Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 2026 Synthesis of sulfur- and oxygen-bridged cationic [4]-helicenes mediated by Friedel–Crafts-S _N Ar tandem reactions for red-light-driven organophotoredox catalysis EN Ryoga Hasebe Graduate School of Environment and Information Sciences, Yokohama National University Rumi Hanada Graduate School of Environment and Information Sciences, Yokohama National University Yuta Tanaka Graduate School of Environment and Information Sciences, Yokohama National University Yuta Goto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Mio Takeuchi Graduate School of Environment and Information Sciences, Yokohama National University Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University Yujiro Hoshino Graduate School of Environment and Information Sciences, Yokohama National University The synthesis of sulfur- and oxygen-bridged cationic [4]-helicenes via a tandem Friedel–Crafts–SNAr reaction of a diaryl sulfide or a diaryl ether with a (thio)salicylic acid has been developed. The sulfur-bridged cationic [4]-helicenes are suitable as catalysts for photoredox reactions under low-energy light sources such as red LED light. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1434-193X 2026 Informatics‐Driven and Automated Optimization in Flow Electrochemical Synthesis e202501237 EN Eisuke Sato Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Akine Tani Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tomohiro Nakahama Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Koichi Mitsudo Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Electrochemical synthesis has emerged as a powerful platform for environmentally sustainable chemical transformations. When integrated with flow chemistry, electrosynthetic processes exhibit enhanced scalability, making them suitable for industrial applications. Recently, the integration of electrochemical flow systems with informatics techniques has accelerated the optimization of reaction conditions. Data-driven strategies facilitate rapid exploration of multidimensional parameter spaces, enabling identification of optimal reaction conditions with high efficiency. These advances have enabled the development of automated optimization systems. This review highlights recent progress in combining electrosynthesis, flow chemistry, and computational tools, focusing on representative examples that illustrate efficient optimization protocols and autonomous reaction development. By showcasing these developments, we discuss how the integration of these technologies is driving innovation in electrochemical synthesis. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0016-6480 380 2026 Constitutive activation of MC1R in the large-billed crow (Corvus macrorhynchos) and its potential role in black plumage 114924 EN Saya Nakano Graduate School of Natural Science and Technology, Okayama University Yuichi Tashiro Graduate School of Natural Science and Technology, Okayama University Hibiki Fukuchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Sayaka Aizawa Graduate School of Natural Science and Technology, Okayama University Sakae Takeuchi Graduate School of Natural Science and Technology, Okayama University Melanin-based plumage coloration in birds is largely regulated by the melanocortin 1 receptor (MC1R), a G protein–coupled receptor that promotes eumelanin synthesis via cAMP signaling. In domestic chickens, constitutively activating mutations such as the MC1R^E (E92K) allele cause melanistic phenotypes, demonstrating that persistent MC1R activation can drive generalized darkening. However, to our knowledge, no experimental study has directly demonstrated constitutive MC1R activation in wild birds exhibiting uniformly black plumage. We investigated the sequence and signaling properties of MC1R from the Large-billed Crow (Corvus macrorhynchos), a species with strongly eumelanin-dominant plumage. Crow MC1R exhibited elevated basal cAMP signaling and minimal responsiveness to α-melanocyte-stimulating hormone (α-MSH) in both stable Chinese hamster ovary (CHO-K1) cells and transient CRE-luciferase assays in HEK293T cells, demonstrating ligand-independent activation comparable to that observed in the melanizing chicken MC1R^E (E92K) allele. Comparative sequence analysis identified multiple substitutions conserved across Corvus species. Among these, E12K and E18K were functionally evaluated based on prior associations with melanism in other birds. Although E12K modestly increased basal signaling in chicken MC1R, E18K alone or in combination with E12K did not reproduce crow-level constitutive activity, and reciprocal substitutions in crow MC1R failed to abolish ligand-independent activation. These findings demonstrate that crow MC1R possesses constitutive activity and suggest that this phenotype reflects lineage-specific modifications rather than a single activating substitution. Our results provide experimental evidence that constitutive MC1R activation is a plausible molecular mechanism that may contribute to the black plumage in the Large-billed Crow, although a direct causal relationship remains to be established. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0017-9310 264 2026 Improving thermal stability of a microcavity emitter for utilization under atmospheric environment 128798 EN Kazuma Isobe Faculty of Environmental, Life, Natural Science and Technology, Okayama University Shota Morishige Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taiyo Sato Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yutaka Yamada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Akihiko Horibe Faculty of Environmental, Life, Natural Science and Technology, Okayama University With the development of micro-fabrication technology, various metamaterials with controlled emission spectra have been proposed as thermal emitters. However, general metamaterials have a risk of deformations and degradation at high temperatures in atmospheric conditions, which is inconvenient for use as a thermal emitter. In this study, we propose a concept to enhance the thermal durability of microcavity-type metamaterials. Although typical microcavities are entirely composed of metal to excite the resonance of electromagnetic waves, we assessed the feasibility of a microcavity consisting of silicon with minimal metal coatings. While usual metals are oxidized at high temperatures, gold is rarely oxidized due to its chemical stability. However, the gold layer deposited on the Si substrate has the potential to melt below 400 °C due to the formation of an Au-Si eutectic alloy, which has a much lower melting point than pure gold. Therefore, we focused on the gold-tungsten bilayer as a suitable metal coating for the silicon microcavity, thereby preventing oxidation and melting that would otherwise influence the emission spectra of the thermal emitter. The numerical analysis ensured that the proposed microcavity exhibited electromagnetic resonance, similar to that of a microcavity entirely composed of metal, unless the metal coating was too thin. The fabricated microcavity with the gold-tungsten coating also exhibited a thermal emission within a limited wavelength range, due to the microcavity resonance. Moreover, the heating experiment revealed that the microcavity with a gold-tungsten coating maintained its emissivity even when heated to 400 °C, which is higher than the oxidation point of tungsten and the melting point of the Au-Si eutectic alloy. Consequently, the gold-tungsten coating would be a reasonable approach to improve the stability of the microcavity-type metamaterial at high temperatures under oxidative conditions. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0046-5755 220 3 2026 Knot surgered elliptic surfaces without 1- and 3-handles for a (2, 2h + 1)-torus knot 29 EN Naoyuki Monden Department of Mathematics, Faculty of Science, Okayama University Reo Yabuguchi Department of Mathematics, Faculty of Science, Okayama University For any positive integers h and n, we show that a knot surgered elliptic surface E(n)T(2,2h+1) for a (2, 2h + 1)-torus knot T (2, 2h + 1) admits a handle decomposition without 1- and 3-handles using a Kirby diagram derived from a Lefschetz fibration on it. As a corollary, an elliptic surface E(1)2,2h+1 has such a handle decomposition. No potential conflict of interest relevant to this article was reported.

The Company of Biologists Acta Medica Okayama 2046-6390 15 2 2026 Gap junction-mediated signaling coordinates Rhodopsin coupling for Drosophila color vision bio062463 EN Xuanshuo Zhang Division of Biological Sciences, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Ryoki Shinjo Division of Biological Sciences, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Manabu Kitamata Division of Health Science, Advanced Comprehensive Research Organization, Teikyo University Shinichi Otsune Division of Biological Sciences, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hideki Nakagoshi Division of Biological Sciences, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University The Drosophila compound eye is composed of approximately 800 ommatidia, and every ommatidium contains eight photoreceptor cells, six outer cells (R1-R6) and two inner cells (R7 and R8), and accessory cells (cone and pigment cells). The expression of rhodopsin genes in R7 and R8 is highly coordinated through an instructive signal from R7 to R8. The activity of the homeodomain protein Defective proventriculus in R1 is also required to transmit this instructive signal, suggesting that cell–cell communication between R7, R1, and R8 is important to generate the pattern of Rh expression in R7/R8 (Rhodopsin coupling). As cell junctions play crucial roles in maintaining the structural and functional integrity of tissues, we tested whether cell junction proteins are involved in the interactions between photoreceptor cells. Here, we demonstrate that gap junction proteins innexin 2 and innexin 7 in accessory cells are necessary for transmitting signals from R7 to R8. In addition, Notch-mediated accessory cell development and Rhodopsin coupling in R7/R8 are highly correlated. Our results provide evidence that functional coupling of two different neurons, R7 and R8, is established through gap junction-mediated signaling from adjacent accessory cells. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0040-4039 179 2026 Visible-light-induced photocatalytic intermolecular cyclization for synthesis of 2,2-diarylchromanes 156034 EN Sakura Kodaki Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Momo Kondo Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science Junta Minato Laboratory of Cellular Drug Discovery and Development, Faculty of Pharmaceutical Sciences, Tokyo University of Science Shoko Itakura Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Makiya Nishikawa Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kosuke Kusamori Laboratory of Cellular Drug Discovery and Development, Faculty of Pharmaceutical Sciences, Tokyo University of Science Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University The photocatalytic cyclization of salicylaldehydes with 1,1-diarylalkenes for the synthesis of 2,2-diarylchromanes has been developed. The catalytic amount of Ir photocatalyst proceeds the cyclization to give the various 2,2-diaryl chromanes under irradiation with blue LEDs. The obtained 2,2-diarylchromanes exhibit noticeable free-radical-scavenging activities, which have been largely unexplored. Notably, the chromane can convert to 2,2-diaryl-2H-naphtho[1,2-b]pyran bearing strong electron withdrawing groups, which are found in various photochromic materials. Thus, the present reaction constitutes a promising tool for the synthesis of functional materials and biologically active compounds. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2211-7156 25 2026 Peptide nanomicelles for NIR light-dependent siRNA delivery 103265 EN Taufik Fatwa Nur Hakim Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mizuki Kitamatsu Department of Applied Chemistry, Kindai University Shoumu Fujimoto Department of Applied Chemistry, Kindai University Kazunori Watanabe Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Takashi Ohtsuki Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University The peptide amphiphile PA8, derived from the GAVILRR peptide, was developed as a carrier for small interfering RNA (siRNA) delivery; however, its RNA interference (RNAi) efficacy was limited owing to predominant endocytotic uptake. In this study, the RNAi efficiency of PA8 nanomicelle/siRNA complexes was enhanced by modifying the nanomicelles with the photosensitizer DY750 and the tumor-homing peptide iRGD. The conjugation of DY750 to the nanomicelles facilitated endosomal escape of the nanomicelle/siRNA complexes, enabling the cytosolic release of siRNA. Additionally, the incorporation of iRGD improved RNAi delivery efficiency in the AsPC-1 pancreatic ductal adenocarcinoma cell line. PA8-DY750-iRGD nanomicelle complexes loaded with siRNA against polo-like kinase 1 (PLK1) achieved an 80% reduction in PLK1 mRNA levels in AsPC-1 cells and a moderate 28% knockdown in NCI-N87 gastric cancer cells. Notably, no RNAi effect was observed in noncancerous 1C3D3 pancreatic cells or HEK293T kidney cells, underscoring the selectivity of this system for AsPC-1 cells. These findings highlight the potential of PA8-DY750-iRGD nanomicelle complexes as a targeted therapeutic platform for specific cancers, particularly pancreatic cancer. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2045-2322 16 1 2026 Liquid–liquid phase separation by caged coacervating peptides 10464 EN Akinari Bando Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mizuki Kitamatsu Department of Applied Chemistry, Kindai University Yuuki Kanazaki Department of Applied Chemistry, Kindai University Rika Tojo Department of Applied Chemistry, Kindai University Kazunori Watanabe Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Takashi Ohtsuki Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Liquid–liquid phase separation is an important biomolecular process in the formation of membraneless intracellular organelles that has inspired the development of artificial droplet systems. We developed caged coacervating peptides (CCPs) based on a histidine-rich squid beak protein sequence. The peptides were caged with a photodeprotectable (7-diethylaminocoumarin-4-yl)methoxycarbonyl group. The CCPs formed coacervates in the caged state and were partially dispersed upon blue-light irradiation. Photo-uncaging occurred rapidly, inducing coacervate dispersion. A mutant CCP with reduced π–π interactions exhibited efficient photo-dependent disassembly and enabled the encapsulation and release of a fluorescently labeled adenosine 5′-triphosphate (Bodipy-ATP) upon irradiation. These CCPs offer an efficient light-controlled approach for biomolecular encapsulation within coacervates and targeted drug delivery. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1472-6831 26 1 2026 Evaluation of contact-active antibacterial properties of cetylpyridinium chloride–graphene oxide coatings on dental restorative and titanium surfaces: an in vitro study 558 EN Keisuke Okubo Department of Periodontics and Endodontics, Field of Medical Development, Okayama University Gen Kano Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Masato Komoda Research Institute for Interdisciplinary Science, Okayama University Hideyuki Kamata Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shin Nakamura Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yuki Shinoda-Ito Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kazuhiro Omori Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Shogo Takashiba Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objective Biofilm formation on dental restorative materials and implant surfaces plays a central role in the development of dental caries, periodontal disease, and peri-implantitis. Durable antimicrobial surface treatments that inhibit bacterial adhesion and biofilm formation remain a significant unmet need in restorative and implant dentistry. Therefore, this study aimed to develop a composite coating combining cetylpyridinium chloride and graphene oxide, and to evaluate its durable antibacterial surface modification under in vitro conditions.<br> Methods A composite coating consisting of cetylpyridinium chloride and graphene oxide was prepared and applied to composite resin and titanium surfaces. Antibacterial activity against Streptococcus mutans and Porphyromonas gingivalis was evaluated using adenosine triphosphate assays and fluorescence-based live/dead staining. Coating retention after washing and air-drying was assessed by optical microscopy and Raman spectroscopy.<br> Results Cetylpyridinium chloride-graphene oxide-coated surfaces showed a significant reduction in bacterial viability compared with phosphate-buffered saline, ethanol, and cetylpyridinium chloride-only controls. Antibacterial effects were maintained after rinsing and air-drying on both composite resin and titanium surfaces. Raman spectroscopy confirmed the persistence of characteristic graphene oxide bands after washing, indicating stable retention of the coating on the material surfaces.<br> Conclusions Cetylpyridinium chloride–graphene oxide coatings demonstrate sustained surface-associated antibacterial activity against key cariogenic and periodontal pathogens and remain stably adhered to common dental restorative and implant materials after washing. These findings suggest that cetylpyridinium chloride–graphene oxide coatings may serve as a durable contact-active surface modification strategy to reduce biofilm formation associated with dental caries and peri-implantitis. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2238-7854 42 2026 An electric field temporarily strengthens zirconia ceramics 1806 1810 EN Akira Kishimoto Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takahiro Shimizu Faculty of Environmental, Life, Natural Science and Technology, Okayama University Mitsuru Nishiyama Faculty of Environmental, Life, Natural Science and Technology, Okayama University Shinya Kondo Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takashi Teranishi Faculty of Environmental, Life, Natural Science and Technology, Okayama University By applying an electric field to yttria-stabilized zirconia (8YSZ) equipped with an inert electrode, oxide ions are localized near the positive electrode, causing it to expand. When polarization was performed under different conditions, it was possible to strengthen the material to 1.5 times that of an untreated sample. The lattice constant of the positive electrode surface after polarization was larger than before polarization. When the Vickers hardness of the positive electrode surface was measured by changing the test load, the smaller the load, the higher the hardness value. Polarization caused oxide ions to move near the positive electrode, filling in the defects and generating an expanded layer with a large lattice constant. It is believed that this was subjected to compressive stress from the bulk layer, which had not changed in volume, resulting in an increase in strength. No potential conflict of interest relevant to this article was reported.

岡山大学教育推進機構 教師教育開発センター Acta Medica Okayama 2186-1323 16 2026 大学院共通科目『リーダーシップとSDGs』の教育モデル構築と成果分析 理論学習・ピアレビュー・省察活動によるリーダーシップ教育の新展開 221 235 EN Mamoru ISHIDA Faculty of General Education and Global Studies, Okayama University Shinichi OTSUNE Graduate student, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Takuya NAKAZAWA Graduate student, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University 10.18926/CTED/70371 　岡山大学大学院では、博士課程人材のリーダーシップ育成に向け、共通科目『リーダーシップとSDGs』を設計・実践している。本科目はSDGsに貢献するリーダー育成に主眼を置き、理論学習・ピアレビュー・省察・グループディスカッション等の手法を組み合わせ、学生同士の学び合い・自己成長の促進を目的としている。本稿では、学部・研究科ごとに学習成果を分析し、理論に基づく省察的学びと協働的な批評活動がリーダーシップ理解や成長に有用であることを明らかにした。本研究は、学術的理論と実践的活動を織り交ぜたモデル構築と、その継続的改善の意義を示している。 No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1043-1802 37 3 2026 A Cysteine-Specific Cationization Strategy for Versatile Antibody Production against Intrinsically Disordered Proteins 580 589 EN Ryui Sakaguchi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Ai Miyamoto Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Rikako Kutsuma Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Takeru Mori Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Daichi Nakashima Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mirei Masui Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Tomoko Honjo Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Midori Futami Department of Bioscience, Faculty of Life Science, Okayama University of Science Mariko Morii Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Toshiyuki Oshiki Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Junichiro Futami Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Several autoantigens relevant to the immune system, especially those targeted by autoantibodies induced by antitumor responses, tend to be rich in disordered regions and are prone to aggregation. This inherent instability presents significant challenges for the production, purification, and analysis of autoantigens in laboratory settings. Cysteine-specific cationization can effectively solubilize and purify these challenging proteins, allowing the isolation of full-length water-soluble antigens in their denatured state. The purified antigens enable accurate multiplex autoantibody assays using a suspension Luminex bead array platform. However, well-validated positive control antibodies are essential to ensuring precise clinical diagnosis. In this study, we prepared and characterized a panel of control antibodies by immunizing rabbits with cysteine-specific S-cationized antigens. The resulting antibodies predominantly recognized linear epitopes and were highly effective as quality control reagents in autoantibody array assays. Additionally, these antibodies maintained their ability to bind to their native, unmodified intracellular counterparts, highlighting the usefulness of this approach for producing antibodies against intrinsically disordered proteins. Although a modest immune response against the S-cationized modification site was observed, it remained minimal and did not affect the usefulness of the antibodies for assay validation. We propose this versatile cysteine-specific cationization platform for managing unstable proteins rich in disordered regions, supporting antigen production for diagnostics, and antibody development for research and validation purposes. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2410-387X 9 4 2025 Role-Based Efficient Proactive Secret Sharing with User Revocation 80 EN Yixuan He Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuta Kodera Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yasuyuki Nogami Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Samsul Huda Interdisciplinary Education and Research Field, Okayama University Proactive secret sharing (PSS), an extension of secret-sharing schemes, safeguards sensitive data in dynamic distributed networks by periodically refreshing shares to counter adversarial attacks. In our previous work, we constructed a non-interactive proactive secret scheme by integrating threshold homomorphic encryption (ThHE) while reducing the communication complexity to 𝑂(𝑛). Not only is refreshing shares important but revoking the shares of users who have left the system is also essential in practical dynamic membership scenarios. However, the previous work was insufficient for supporting explicit user revocation. This study strengthens the description of roles for authorized users and proposes a scheme to achieve non-interactive share refresh and dynamic user management. In each epoch, authorized users are classified into three roles: retain, newly join, and rejoin, and they receive a broadcast of the compact ciphertext encoding both the refresh information and the revocation instructions from the trusted center (dealer). Authorized users independently derive new shares through homomorphic computations, whereas revoked users are unable to generate new shares. Hash functions are used to bind revocation parameters to the cryptographic hashes of valid users in order to guarantee integrity during revocation, allowing for effective verification without compromising non-interactivity. Our new scheme not only extends the revocation structure but also preserves the 𝑂(𝑛) communication complexity. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 1424-8220 25 21 2025 Integrated Authentication Server Design for Efficient Kerberos–Blockchain VANET Authentication 6651 EN Maya Rahayu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Md. Biplob Hossain Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Samsul Huda Interdisciplinary Education and Research Field, Okayama University Yasuyuki Nogami Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Vehicular Ad Hoc Network (VANET) is a fundamental component of the intelligent transportation systems (ITS), providing critical road information to users. However, the volatility of VANETs creates significant vulnerabilities from malicious actors. Thus, verifying joining entities is crucial to maintaining the VANET’s communication security. Authentication delays must stay below 100 ms to meet VANET requirements, posing a major challenge for security. Our previous research introduced a Kerberos–Blockchain (KBC) authentication system that contains two main components separately: Authentication Server (AS) and Ticket Granting Server (TGS). However, this KBC architecture required an additional server to accommodate increasing vehicle volumes in urban environments, leading to higher infrastructure costs. This paper presents an integrated authentication server that merges AS and TGS into a Combined Server (CBS) while retaining blockchain security. We evaluate it using OMNeT++ with SUMO for traffic simulation and Ganache for blockchain implementation. Results show that CBS removes the need for an extra server while keeping authentication delays under 100 ms. It also improves throughput by 104% and reduces signaling overhead by 45% compared to KBC. By optimizing authentication without compromising security, the integrated server greatly enhances the cost-effectiveness and efficiency of VANET systems. No potential conflict of interest relevant to this article was reported.

BON VIEW PUBLISHING PTE Acta Medica Okayama 2810-9503 5 1 2025 A Study on Zeek IDS Effectiveness for Cybersecurity in Agricultural IoT Networks 133 142 EN Samsul Huda Interdisciplinary Education and Research Field, Okayama University Muhammad Bisri Musthafa Graduate School of Environmental, Life, Natural Science and Technology, Okayama University S. M. Shamim Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yasuyuki Nogami Graduate School of Environmental, Life, Natural Science and Technology, Okayama University As agriculture moves toward Agriculture 4.0, which uses Internet of Things (IoT) devices to collect data in real time and monitor things from a distance, these networks are becoming increasingly vulnerable to cyberattacks. A common method used to protect against these kinds of threats is the use of intrusion detection systems (IDS). However, the agricultural environment is often changing and has limited resources, which makes cybersecurity challenging. Several available IDS tools are not designed to work properly in places with few resources, intermittent access, and unpredictable network conditions. This paper investigates the performance of Zeek, an open-source IDS, in identifying potential threats in agricultural IoT networks. We performed both offline and real-time experiments: offline analysis used pcap files from the Stratosphere Laboratory dataset, and real-time evaluation involved simulated live attack scenarios, focusing on unauthorized access attempts and distributed denial-of-service (DDoS) attacks. Zeek's performance was assessed based on CPU and memory utilization, as well as quality of service (QoS) metrics. From the experimental results, we found that Zeek was quite effective in protecting agricultural IoT networks against typical threats. Memory usage remained stable around 5% during offline analysis and under 20% during active attacks. However, CPU usage was more volatile, peaking at 120% during DDoS events. In terms of QoS, the system maintained a good throughput (1,375 kbits/s) with minimal packet loss (0.000186%). Among the attack types that we tested, brute force attacks, which represent attempts at unauthorized access, had the strongest effect on network performance, increasing delay to 2.159 ms and jitter to 0.793 ms. It seems clear that a heavier traffic load during such attacks can interfere with QoS. On the basis of our observation, we recommend practical deployment strategies for agricultural IoT systems that take these limitations into consideration, aiming to keep networks both secure and efficient under pressure. No potential conflict of interest relevant to this article was reported.

岡山大学理学部地球科学科 Acta Medica Okayama 1340-7414 32 1 2026 寒風古窯跡群須恵器の岩石学的研究 9 19 EN Taiji ANAMI Department of Earth Sciences, Okayama University Toshio NOZAKA Department of Earth Sciences, Okayama University Osamu KIMURA Department of Archaeology, Osaka University 10.18926/ESR/70295 　The Sabukaze kiln site, a representative ancient tunnel-kiln site in the Kibi region, worked during the Asuka period (from early 7th century to early 8th century) to produce Sue ware including jars, cups, coffins, and ornamental tiles. To determine the provenance of the materials used for the Sue ware, we carried out petrological analyses of 13 Sue sherds, including optical microscopy, X-ray diffractometry, X-ray fluorescence spectroscopy, Raman spectroscopy, and electron-probe analysis. In spite of the difference of production time, all the Sue sherds show close similarities in modal proportion of mineral inclusions with dominant quartz and feldspar, and minor volcanic glass, in chemical compositions of feldspar and interstitial matrix, and in whole-sherd chemical composition. These similarities suggest that the paste materials of the Sabukaze Sue ware were commonly derived from weathered rhyolitic rocks and obtained from the same or neighboring mining site(s) located near the kiln site. No potential conflict of interest relevant to this article was reported.

岡山大学理学部地球科学科 Acta Medica Okayama 1340-7414 32 1 2026 岡山平野児島湾岸部での微動アレイ探査 1 7 EN Nobuyuki YAMADA Faculty of Science and Technology, Kochi University Hiroshi TAKENAKA Department of Earth Sciences, Okayama University 10.18926/ESR/70294 　This report describes microtremor array observations conducted at two sites for deep exploration and three sites for shallow exploration around Kojima Bay area in the southern Okayama Plain. Based on these records, the ground velocity structures were estimated. The results yielded solutions indicating the depth of the top of the seismic base layer (equivalent to 3 km/s layer) ranges from 140 to 300 m, while the depth of the top of the engineering basement layer (equivalent to 0.6 km/s layer) is approximately about 13–14 m. The shallow exploration results also suggested the possible presence of an inversion layer. These estimated velocity structure models provided a reasonable explanation for the observed phase velocities. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 0022-2623 69 5 2026 Discovery of Thermal Sensitizers That Inhibit Heat-Induced SAFB Granule Formation 5944 5955 EN Yuji Furutani Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Natsuki Shimasaki Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Riko Yamada Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Takashi Ohtsuki Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kazunori Watanabe Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Hyperthermia is a minimally invasive cancer treatment based on heat stress-induced apoptosis. Its therapeutic efficacy, however, is often limited by tumor heterogeneity and acquired thermotolerance. Therefore, combination strategies involving hyperthermia and chemotherapy have been developed to enhance the therapeutic efficacy. Previously, we showed that SB366791 enhanced heat-induced apoptosis by inhibiting heat stress-induced scaffold attachment factor B (SAFB) granule formation, although its proapoptotic activity was insufficient. Therefore, we screened to identify novel compounds that enhance heat-induced apoptosis by suppressing SAFB granule formation. We identified four hit compounds that inhibited SAFB granule formation, all exhibiting thermal enhancement ratios > 1.0─that significantly enhanced heat-induced apoptosis efficiency. Additionally, the tumor volume in mice treated with a combination of Z19024498 and hyperthermia was significantly smaller than that in mice treated with hyperthermia or Z19024498. These results indicate that the identified compounds, specifically Z19024498, have potential as thermal sensitizers for hyperthermia therapy. No potential conflict of interest relevant to this article was reported.

The Carbon Society of Japan Acta Medica Okayama 2436-5831 4 3 2025 Synthesis and applications of porous carbonaceous materials with inherited molecular structural features from the precursor molecules 179 187 EN Koki Chida Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Takeharu Yoshi Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Kazuhide Kamiya Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Ryota Sakamoto Department of Chemistry, Graduate School of Science, Tohoku University Fumito Tani Institute for Materials Chemistry and Engineering, Kyushu University Tomoki Ogoshi Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University Hirotomo Nishihara Institute of Multidisciplinary Research for Advanced Materials, Tohoku University The carbonization of organic crystalline materials, such as metal organic frameworks and covalent organic frameworks, has emerged as a promising approach for producing functional porous carbonaceous materials. However, both the chemically defined long-term ordered structures and the local chemical structures derived from these precursor materials are generally lost, resulting in amorphous carbons. As a result, controlling the molecular-level structure of nanoporous carbons remains a significant challenge. We report a new bottom-up synthesis approach for porous carbons with a molecular-level design, involving the carbonization of well-designed precursor molecules by thermal polymerization. Among the resulting carbons, ordered carbonaceous frameworks, which contain a high-density of regularly aligned single-atomic metal species, have been identified as promising platforms for single-atom catalysts. This approach also enables the synthesis of various three-dimensional porous carbons that reflect the structural features of their precursor molecules. Recent progress in the synthesis and applications of porous carbons derived from molecular precursors is summarized, highlighting their potential for the development of functional materials. No potential conflict of interest relevant to this article was reported.

Frontiers Media SA Acta Medica Okayama 1664-462X 16 2025 Structural analysis of PSI-ACPI and PSII-ACPII supercomplexes from a cryptophyte alga Rhodomonas sp. NIES-2332 1716939 EN Wenyue Zhang Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nozomi Yonehara Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Mizuki Ishii Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Haowei Jiang Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Romain La Rocca Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Pi-Cheng Tsai Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hongjie Li Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Koji Kato Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Fusamichi Akita Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Jian-Ren Shen Advanced Research Field, Research Institute for Interdisciplinary Science, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Light energy is converted to chemical energy by two photosystems (PSI and PSII) in complex with their light-harvesting complex proteins (LHCI and LHCII) in photosynthesis. Rhodomonas is a member of cryptophyte alga whose LHCs contain unique chlorophyll a/c proteins (ACPs) and phycobiliproteins. We purified PSI-ACPI and PSII-ACPII supercomplexes from a cryptophyte Rhodomonas sp. NIES-2332 and analyzed their structures at high resolutions of 2.08 Å and 2.17 Å, respectively, using cryo-electron microscopy. These structures are largely similar to those reported previously from two other species of cryptophytes, but exhibited some differences in both the pigment locations and subunit structures. A part of the antenna subunits of both photosystems is shifted compared with the previously reported structures from other species of cryptophytes, suggesting some differences in the energy transfer rates from the antenna to the PSI and PSII cores. Newly identified lipids are found to occupy the interfaces between the antennae and cores, which may be important for assembly and stabilization of the supercomplexes. Water molecules surrounding three iron-sulfur clusters of the PSI core are found in our high-resolution structure, some of which are conserved from cyanobacteria to higher plants but some are different. In addition, our structure of PSII-ACPII lacks the subunits of oxygen-evolving complex as well as the Mn4CaO5 cluster, suggesting that the cells are in the S-growth phase, yet the PSI-ACPI structure showed the binding of PsaQ, suggesting that it is in an L-phase. These results suggest that the S-phase and L-phase can co-exist in the cryptophytic cells. The high-resolution structures of both PSI-ACPIs and PSII-ACPIIs solved in this study provide a more solid structural basis for elucidating the energy transfer and quenching mechanisms in this group of the organisms. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2041-6520 17 9 2026 Gaseous CO2 electrolysis: latest advances in electrode and electrolyzer technologies toward abating CO2 emissions 4363 EN Kazuhide Kamiya Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Sora Nakasone Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Ryo Kurihara Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Asato Inoue Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Hazuki Irie Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Shoko Nakahata Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Satoshi Taniguchi Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 Thuy T. H. Nguyen Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 Sho Kataoka Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 The conversion of CO2 into multicarbon (C2+) products via electrochemical reduction is considered a key technology for the sustainable production of fuels and chemicals. The performance of high-rate gaseous CO2 electrolysis is governed by interrelated factors such as the electrocatalysts, electrodes, electrolytes, and cell architectures. Despite the intensive focus on catalyst research, systematic studies addressing the other components remain scarce, leaving critical gaps in our understanding toward achieving higher performance in CO2 electrolysis systems. The nanoscale design of catalyst surface electronic structures and the macroscale design of electrodes and electrolyzer architectures both influence the overall activity of the electrochemical system. In designing macroscale components, it is necessary to establish benchmarks based on a comprehensive evaluation of CO2 emissions for the entire electrolysis process, because these parameters are directly linked to output metrics such as current density and cell voltage under practical operating conditions. This review summarizes recent advances in electrodes and electrolyzers, and through life-cycle assessment (LCA), evaluates key performance indicators (KPIs) for achieving negative emissions and assesses the current technology readiness of CO2 electrolysis. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2589-0042 28 9 2025 Extensive urine production in euryhaline red stingray for adaptation to hypoosmotic environments 113274 EN Naotaka Aburatani Atmosphere and Ocean Research Institute, The University of Tokyo Wataru Takagi Atmosphere and Ocean Research Institute, The University of Tokyo Marty Kwok-Shing Wong Atmosphere and Ocean Research Institute, The University of Tokyo Nobuhiro Ogawa Atmosphere and Ocean Research Institute, The University of Tokyo Shigehiro Kuraku Department of Genomics and Evolutionary Biology, National Institute of Genetics Mana Sato Department of Genomics and Evolutionary Biology, National Institute of Genetics Kazuhiro Saito Ushimado Marine Institute, Faculty of Science, Okayama University Waichiro Godo Ushimado Marine Institute, Faculty of Science, Okayama University Tatsuya Sakamoto Ushimado Marine Institute, Faculty of Science, Okayama University Susumu Hyodo Atmosphere and Ocean Research Institute, The University of Tokyo Maintaining water balance is a prerequisite for all organisms. Euryhaline elasmobranchs face the severest water-influx potential in fresh water (FW), as they retain high concentrations of urea even in hypotonic environments. To elucidate how they overcome this osmotic challenge, we assessed urine output in conscious euryhaline red stingrays (Hemitrygon akajei). Following acclimation to 5% diluted seawater, the stingrays increased urinary output by 87-fold―the greatest change observed in vertebrates―partly due to 6.8-fold increase in glomerular filtration rate (GFR). In the nephron, expressions of Aquaporin-1 (Aqp1), Aqp3, and Aqp15 were strongly downregulated in FW, indicating that tubular diuresis bridges the gap between GFR and final urine volume. Meanwhile, FW-acclimation upregulated Aqp1 and Aqp4 in the distinct bundle structure, which promotes urea reabsorption. Euryhaline elasmobranchs resolve the huge osmotic challenge of FW by excreting massive amounts of water and retaining osmolytes including urea through coordinated regulation of GFR and Aqp expressions. No potential conflict of interest relevant to this article was reported.

Japanese Society of Tribologists Acta Medica Okayama 1881-2198 20 4 2025 Tribological Properties of Amorphous-SiC-Based Coatings on Al2O3 Substrates in Normal Saline 212 219 EN Tadashi Shiota Faculty of Environmental, Life, Natural Science and Technology, Okayama University Daiki Taniya Graduate School of Natural Science and Technology, Okayama University Kazuma Shimazaki Graduate School of Natural Science and Technology, Okayama University Chiyu Nakano Department of Comprehensive Technical Solutions, Okayama University Yuya Omiya Faculty of Environmental, Life, Natural Science and Technology, Okayama University Masahiro Fujii Faculty of Environmental, Life, Natural Science and Technology, Okayama University Amorphous SiC (a-SiC)-based coatings containing not only Si–C bonds but also C–Si–O, C–C, and Si–O2 bonds were deposited on Al2O3 substrates via pulsed laser deposition. Sliding tests using SiC ceramic balls in normal saline revealed that the coating exhibited a low friction coefficient of 0.05-0.06 at a shorter running-in process than SiC bulk ceramic plates. The specific wear rate of the coating was also lower than that of the SiC plate. Reactive molecular dynamics simulations revealed that the C–Si–O bonds in the coating facilitated the generation of Si–O units, which contained Si–O bonds but no Si-C bonds, through tribochemical reactions with water, resulting in superior tribological properties in normal saline compared to those of SiC plates. These findings demonstrate that a-SiC-based coatings containing C–Si–O bonds are promising as low-friction and low-wear coatings for biomedical implants such as ceramic joint prostheses. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2590-1230 29 2026 Unified 2D polygon-based CAM framework integrating tool path generation, machinability evaluation, and cutting-force simulation 108948 EN Kazuki Kaneko Faculty of Environmental, Life, Natural Science and Technology, Okayama University Hiroto Takayasu Graduate School of Science and Engineering, Ibaraki University Atsuya Suzuki Mechanical Systems Engineering Program, Okayama University Hiroyuki Kodama Faculty of Environmental, Life, Natural Science and Technology, Okayama University This study proposes a unified two-dimensional (2D) polygon-based computer-aided manufacturing (CAM) framework that enables tool path generation, machinability evaluation, material removal simulation, and cutting-force prediction within a single computational environment. The proposed method represents three-dimensional geometries as aggregates of orthogonal 2D polygon sets, obtained by slicing the model in the xy-, yz-, and zx-parallel planes and superposing the three polygonal datasets. A novel convolutional offsetting algorithm is developed to perform three-dimensional inflation and shrinkage by incorporating adjacent cross-sectional relationships, thereby achieving accurate 3D offsets independent of the slicing orientation. The inflated 2D polygons are directly utilized to generate contour and scanning tool paths, and sequential inflation–shrinkage analysis enables visualization of unmachinable regions for tool accessibility evaluation. Furthermore, the framework integrates an instantaneous cutting force model that accurately predicts the cutting force waveform by detecting intersections between the cutting edge points and 2D polygon aggregations. The system is experimentally validated via ball-end milling. The results demonstrate that tool paths can be generated in under one minute using only a CPU. Furthermore, the simulated cutting forces closely align with experimental measurements. These findings demonstrate that the proposed 2D polygon-based framework provides an efficient and extensible foundation for integrating mechanical simulation and tool-path generation. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1759-9954 16 47 2025 Synthesis of sterically unhindered Lewis acidic boron-doped π-conjugated polymers 5035 5039 EN Naoki Takahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University We report the synthesis of sterically unhindered boron-doped π-conjugated polymers via polymerization of organo-dilithium reagents with boron trichloride. The resulting polymer exhibits Lewis acidity and catalyzes the transesterification of methyl benzoate. This performance is attributed to the electron-accepting ability, and thermally labile Lewis acid–base interactions, facilitating catalytic turnover. No potential conflict of interest relevant to this article was reported.

International Union of Crystallography (IUCr) Acta Medica Okayama 2056-9890 82 2 2026 Crystal structure of tris[4-(3,4-dimethoxythiophen-2-yl)phenyl]amine E82 EN Masafumi Yano Kansai University Yukiyasu Kashiwagi Osaka Research Institute of Industrial Science and Technology Koki Oishi Kansai University Minori Yano Kansai University Koichi Mitsudo Okayama University In the title compound tris­[4-(3,4-di­meth­oxy­thio­phen-2-yl)phen­yl]amine (DMOT-TPA), C36H33NO6S3, the central nitro­gen atom shows no pyramidalization, with the three para-phenyl­ene rings arranged in a propeller-like geometry. Each thio­phene ring is twisted by about 25–29° relative to the adjacent phenyl­ene ring, giving a distorted π-conjugated framework. In the crystal, mol­ecules are linked through multiple C―H⋯π inter­actions into two-dimensional sheets, which extend into a three-dimensional network. A Cambridge Structural Database survey revealed no prior examples of tri­phenyl­amines bearing 3,4-di­meth­oxy­thio­phen units at the para positions. This unique structure provides new insights into the design of redox-active organic materials. No potential conflict of interest relevant to this article was reported.

American Association for the Advancement of Science (AAAS) Acta Medica Okayama 2375-2548 11 44 2025 Structural insights into the divergent evolution of a photosystem I supercomplex in Euglena gracilis eaea6241 EN Koji Kato Research Institute for Interdisciplinary Science, Advanced Research Field, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yoshiki Nakajima Research Institute for Interdisciplinary Science, Advanced Research Field, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Runa Sakamoto Research Institute for Interdisciplinary Science, Advanced Research Field, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Minoru Kumazawa Institute of Low Temperature Science, Hokkaido University Kentaro Ifuku Graduate School of Agriculture, Kyoto University Takahiro Ishikawa Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University Jian-Ren Shen Research Institute for Interdisciplinary Science, Advanced Research Field, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Atsushi Takabayashi Institute of Low Temperature Science, Hokkaido University Ryo Nagao Faculty of Agriculture, Shizuoka University Photosystem I (PSI) forms supercomplexes with light-harvesting complexes (LHCs) to perform oxygenic photosynthesis. Here, we report a 2.82-angstrom cryo–electron microscopy structure of the PSI-LHCI supercomplex from Euglena gracilis, a eukaryotic alga with secondary green alga-derived plastids. The structure reveals a PSI monomer core with eight subunits and 13 asymmetrically arranged LHCI proteins. Euglena LHCIs bind diadinoxanthin, which is one of the carotenoids typically associated with red-lineage LHCs and is not present in the canonical LHCI belt found in green-lineage PSI-LHCI structures. Phylogenetic analysis shows that the Euglena LHCIs originated from LHCII-related clades rather than from the green-lineage LHCI group and that the nuclear-encoded PSI subunit PsaD likely originated from cyanobacteria via horizontal gene transfer. These observations indicate a mosaic origin of the Euglena PSI-LHCI. Our findings uncover a noncanonical light-harvesting architecture and highlight the structural and evolutionary plasticity of photosynthetic systems, illustrating how endosymbiotic acquisition and lineage-specific adaptation shape divergent light-harvesting strategies. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2694-2445 5 6 2025 Electronic Structure of the S1 State Manganese Cluster in Photosystem II Investigated Using Q-Band Selective Hole-Burning 660 671 EN Shinya Kosaki Department of Physics, Graduate School of Science, Nagoya University Naohiko Nakamura Department of Physics, Graduate School of Science, Nagoya University Yoshiki Nakajima Research Institute for Interdisciplinary Science, Advanced Research Field, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Jian-Ren Shen Research Institute for Interdisciplinary Science, Advanced Research Field, and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyuki Mino Department of Physics, Graduate School of Science, Nagoya University The electronic structure of the S1 state of photosystem II (PSII) was investigated using selective hole burning of Q-band pulsed electron paramagnetic resonance. The free induction decay and spin–echo signals of the tyrosine radical YD• in the plant PSII oscillated because of the magnetic dipole–dipole interaction with the S1 state Mn cluster. The initial period was 410 ns (2.44 MHz) and was assigned to the S = 1 spin state. Based on the oscillation analysis, both Mn1 and Mn4 and both Mn2 and Mn3 were assigned as Mn(III) and Mn(IV), respectively, which is consistent with the quantum chemical calculations. The 410 ns period was accounted for in the simplified model using the isotropic spin density distribution ratio [1.6:–1.1:–1.1:1.6] for Mn1–4 ions. This oscillation was identical with that observed in the presence of methanol. The oscillation decreased in PsbP/Q- and PsbO/P/Q-depleted PSII. In Thermosynechococcus vulcanus, two periods, 390 ns (2.56 MHz) and 630 ns (1.59 MHz), were detected, indicating that the cyanobacterial S1 state includes two isomers, S = 1 and S ≥ 2 spins. The S ≥ 2 spin was not detected in PsbO/U/V-depleted PSII without polyethylene glycol. The S ≥ 2 state was consistent with the reported quantum chemical calculation using S = 3. A simplified model accounted for the S = 1 state as the spin density distribution [1.8:–1.3:–1.3:1.8] and for the S ≥ 2 state as the isotropic spin density distribution [−0.5:0.5:0.5:0.5] for Mn1–4 ions. In combination with quantum chemical calculations, the most probable protonated structure is W1 = H2O, W2 = H2O, O4 = O2–, and O5 = O2– for the S1 state. These results demonstrate that the selective hole burning method is a powerful tool to complement X-ray studies to determine the valence and protonation structure of manganese clusters, not only in the S1 state but also in higher S-states and general metal clusters, which would provide important insights into the water oxidation mechanism. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2079-6374 16 1 2026 Magnetic Detection of Cancer Cells Using Tumor-Homing Peptide-Modified Magnetic Nanoparticles 45 EN Shengli Zhou Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yuji Furutani Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kei Yamashita Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Sakuya Kako Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kazunori Watanabe Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Toshihiko Kiwa Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Takashi Ohtsuki Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Magnetic nanoparticles (MNPs) provide a platform for target detection because of their magnetic responsiveness to alternating magnetic fields (AMFs). We developed a detection method using MNPs modified with tumor-homing peptides (THPs), PL1 and PL3, which selectively bind to protein components enriched in malignant tissues. THP-MNPs were synthesized using maleimide-PEG-NHS linkers and characterized using transmission electron microscopy. Human glioblastoma cancer U87MG and normal tissue-derived HEK293 cells were incubated with THP-MNPs, and the magnetic signals were measured using a high-temperature superconducting quantum interference device (SQUID) magnetometer under an AMF (1.06 kHz). Dark-field microscopy confirmed the preferential binding of THP-MNPs to U87MG cells. In the absence of cells, THP-MNPs exhibited AMF-dependent signal enhancement, which correlated with particle size reduction due to THP release. This increase was completely suppressed in the presence of U87MG cells, indicating a strong THP-mediated interaction. PL3-MNPs exhibited superior discrimination between malignant and non-malignant cells. These results demonstrate that SQUID-based magnetic measurements using THP-MNPs enable rapid and label-free cancer cell detection. No potential conflict of interest relevant to this article was reported.

Laser Institute of America Acta Medica Okayama 1042-346X 37 1 2025 High-quality welding of copper and aluminum by angled laser irradiation and insert metals 012041 EN Yasuhiro Okamoto Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuki Yamada Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Akira Okada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Masaki Miyake Kataoka Corporation Takeshi Yamamura Kataoka Corporation Katsutoshi Nagasaki Kataoka Corporation Norio Nishi Kataoka Corporation Copper is an important material in order to use electricity effectively, and aluminum is also an attractive material to perform lightweight construction. Laser welding of copper and aluminum is required, and there are some reports to weld copper and aluminum firmly by laser irradiation from the aluminum side. On the other hand, laser irradiation from the copper side requires high power density to generate a keyhole, which causes the strong convection of molten aluminum into copper. Thus, brittle intermetallic compounds with rich aluminum result in the deterioration of joining strength. Angled laser irradiation enables mild heat input to the aluminum side, and the combination of angled and superposed irradiation of blue and near-infrared (NIR) lasers achieved a remarkable increase of breaking strength. However, the breaking strength is still lower than the base materials. Therefore, insert materials between copper and aluminum plates were investigated by the angled irradiation of blue and NIR lasers from the copper side. The breaking strength with insert materials showed higher values in the order of titanium mesh, nickel foil, and nickel mesh, and its value with the nickel mesh was close to the tensile strength of aluminum in a cross tensile test. Further improvement of breaking strength is possible by inserting the nickel mesh between copper and aluminum plates in the case of angled irradiation of blue and NIR lasers even from the copper side. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0378-4371 684 2026 Longitudinal-field fidelity susceptibility analysis of the 𝐽1-𝐽2 transverse-field Ising model around 𝐽2∕𝐽1 ≈ 0.5 131245 EN Yoshihiro Nishiyama Department of Physics, Faculty of Science, Okayama University The square-lattice 𝐽1-𝐽2 transverse-field (TF) Ising model was investigated with the exact diagonalization (ED) method. In order to analyze the TF-driven phase transition, we applied the longitudinal-field fidelity susceptibility 𝜒(ℎ)𝐹, which is readily evaluated via the ED scheme. Here, the longitudinal field couples with the absolute value of the magnetic moment |𝑀| rather than the raw 𝑀 so that the remedied fidelity susceptibility exhibits a peak around the critical point; note that the spontaneous magnetization does not appear for the finite-size systems. As a preliminary survey, the modified fidelity susceptibility 𝜒(ℎ)𝐹 is applied to the analysis of criticality for 𝐽2 = 0, where a number of preceding results are available. Thereby, properly scaling the distance from the multi-criticality, 𝜂 = 0.5−𝐽2, the 𝜒(ℎ)𝐹 data were cast into the crossover-scaling formula, and the multi-critical exponent for 𝜒(ℎ)𝐹 is estimated. The result is cross-checked by the numerically evaluated 𝛽-function behavior. No potential conflict of interest relevant to this article was reported.

Iron and Steel Institute of Japan Acta Medica Okayama 0915-1559 65 13 2025 Heat Transfer Enhancement by Forming Bridges among Reactive Particles in a Packed Bed Reactor of a Solid-gas Chemical Heat Storage System 2097 2104 EN Koichi Nakaso Faculty of Environmental, Life Natural Science and Technology, Okayama University Kenji Shimada Graduate School of Natural Science and Technology, Okayama University Yasushi Mino Faculty of Environmental, Life Natural Science and Technology, Okayama University Kuniaki Gotoh Faculty of Environmental, Life Natural Science and Technology, Okayama University In this study, the enhancement of the thermal output of solid-gas chemical heat storage systems was investigated. Bridges made of high-thermal conductivity materials were formed among reactive particles by drying a slurry which contained graphite powder as a thermal additive and dispersant in a packed-bed reactor. First, the effect of the volume ratio of the dispersant on effective thermal conductivity was investigated. The optimum volume ratio of dispersant to graphite powder was determined. Furthermore, repetitive bridge formation increased the effective thermal conductivity. Based on these results, we investigated the thermal response of the energy-discharge process. Consequently, the temperature distribution in the radial direction of the reactor decreased owing to the formation of bridges. In addition, the thermal energy generated by the adsorption of water vapor onto the adsorbent was effectively transferred to the reactor wall. The thermal output was estimated based on the experimental results. The thermal output was increased by the formation of bridges. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2405-8440 11 11 2025 Suppression of defect in plated film on AMed metal products by electron beam polishing e43440 EN Togo Shinonaga Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuki Matsuda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Akira Okada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Additively manufactured (AMed) metal products with high shape accuracy can be produced by laser powder bed fusion (LPBF). However, the AMed metal products have large surface roughness due to the arrangement of bead shape. Surface irregularities such as spatter and small cavity are also generated on the surface. Furthermore, elemental composition of AMed metal products may be changed from that of original metal powder due to oxidation of surface. On the other hand, electroless plating has been applied to improvement of surface functions. However, defect is often generated in the plated film due to surface irregularities and oxidation of base material. Therefore, surface smoothing methods are required for suppression of defect in plated film.<br> In this study, surface smoothing and surface repairing of AMed aluminum (Al) alloy were performed by electron beam (EB) polishing with large-area EB. After the EB polishing, electroless plating was conducted on the AMed Al alloy, and suppression of defect in plated film was proposed. Experimental results show that surface smoothing, surface repairing and removal of oxidization layer of AMed Al alloy can be done simultaneously by the EB polishing. Furthermore, the plated film without defect can be successfully formed on the EB polished Al alloy. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0010-9452 194 2026 Increasing visual uncertainty modulates multisensory decision-making 50 62 EN Xiangfu Yang Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Weiping Yang Department of Psychology, Faculty of Education, Hubei University Yinghua Yu Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yoshimichi Ejima Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Jiajia Yang Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University The brain integrates and transforms information from multiple senses to make optimal decisions, a process that is critical for navigating complex environments with perceptual uncertainty. Despite a growing consensus that individuals adapt flexibly to uncertain sensory input, whether increasing visual uncertainty influences the decision process itself or other, non-decision sensory processes during multisensory decision-making are unclear. Here, an audiovisual categorization task was used to examine the responses of human participants (N = 30) to visual and audiovisual stimuli under low-, medium-, and high-uncertainty conditions. Modeling the behavioral data using a drift‒diffusion model indicated that increased visual uncertainty in the audiovisual context decreased the evidence accumulation rate but had no effect on non-decision processes. Electrophysiological recordings confirmed and expanded upon these results: increased visual uncertainty in the audiovisual context reduced the amplitude during the late decision-making stage (300–380 msec) but had no effect on the amplitude during the early sensory encoding stage (140–220 msec). More importantly, electroencephalography analyses revealed that audiovisual integration in the early sensory encoding stage occurred robustly across all visual uncertainty conditions, whereas audiovisual integration in the late stage occurred only under medium and high visual uncertainty conditions. This study demonstrated that increased visual uncertainty modulates the decision process itself rather than early sensory encoding during multisensory decision-making. Moreover, multisensory integration strategies dynamically adapt to increasing visual uncertainty by engaging different mechanisms to maintain effective decision-making. No potential conflict of interest relevant to this article was reported.

American Astronomical Society Acta Medica Okayama 0004-637X 992 1 2025 Observing Supernova Neutrino Light Curves with Super-Kamiokande. VI. A Practical Data Analysis Technique Considering Realistic Experimental Backgrounds 27 EN Fumi Nakanishi Department of Physics, Okayama University Ken’ichiro Nakazato Faculty of Arts and Science, Kyushu University Masayuki Harada Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo Yusuke Koshio Department of Physics, Okayama University Ryuichiro Akaho Faculty of Science and Engineering, Waseda University Yosuke Ashida Department of Physics, Tohoku University Akira Harada National Institute of Technology, Ibaraki College Masamitsu Mori Division of Science, National Astronomical Observatory of Japan Kohsuke Sumiyoshi National Institute of Technology, Numazu College Yudai Suwa Department of Earth Science and Astronomy, The University of Tokyo Roger A. Wendell Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, The University of Tokyo Masamichi Zaizen Department of Earth Science and Astronomy, The University of Tokyo Neutrinos from supernovae, especially those emitted during the late phase of core collapse, are essential for understanding the final stages of massive star evolution. We have been dedicated to developing methods for the analysis of neutrinos emitted during the late phase and observed at Super-Kamiokande (SK). Our previous studies have successfully demonstrated the potential of various analysis methods in extracting essential physical properties; however, the lack of background consideration has limited their practical application. In this study, we address this issue by incorporating a realistic treatment of the experimental signal and background events with the on-going SK experiment. We therefore optimize our analysis framework to reflect realistic observational conditions, including both signal and background events. Using this framework we study several long-time supernova models, simulating the late phase neutrino observation in SK and focusing in particular on the identification of the last observed event. We discuss the possibility of model discrimination methods using timing information from this last observed event. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 79 6 2025 Exacerbation of Proteinuria in a Patient with Behçet’s Disease and IgA Nephropathy Following Colchicine Discontinuation 457 461 EN Tomohiko Asakawa Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Haruhito A. Uchida Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Yu Katayama Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Yoshimasa Sakurabu Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Katsuyoshi Katayama Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Yasuhiro Onishi Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Natsumi Matsuoka-Uchiyama Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Hidemi Takeuchi Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Keiko Tanaka Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Kenji Tsuji Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Ryoko Umebayashi Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Rika Takemoto Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Jun Wada Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Case Report 10.18926/AMO/69849 This case involves a 23-year-old male who was diagnosed with Behçet’s disease 5 years ago and managed with colchicine. Two months ago, he underwent renal biopsy due to abnormal urinalysis and kidney dysfunction, leading to a diagnosis of IgA nephropathy. He subsequently underwent tonsillectomy followed by glucocorticoid pulse therapy. However, after the tonsillectomy, discontinuing colchicine led to increased proteinuria, despite the glucocorticoid pulse therapy. Upon reintroducing colchicine, urinary protein excretion decreased, achieving incomplete remission. These findings suggest that colchicine may be effective in decreasing proteinuria in patients with Behçet’s disease complicated by IgA nephropathy. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2076-3425 15 11 2025 Sensory Modality-Dependent Interplay Between Updating and Inhibition Under Increased Working Memory Load: An ERP Study 1178 EN Yuxi Luo Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Ao Guo Department of Psychology, Institute of Education, China West Normal University Jinglong Wu Faculty of Biomedical Engineering, Shenzhen University of Advanced Technology Jiajia Yang Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Background/Objectives: Working memory (WM) performance relies on the coordination of updating and inhibition functions within the central executive system. However, their interaction under varying cognitive loads, particularly across sensory modalities, remains unclear. Methods: This study examined how sensory modality modulates flanker interference under increasing WM loads. Twenty-two participants performed a visual n-back task at three load levels (1-, 2-, and 3-back) while ignoring visual (within-modality) or auditory (cross-modality) flankers. Results: Behaviorally, increased WM load (2- and 3-back) led to reduced accuracy (AC) and prolonged reaction times (RTs) in both conditions. In addition, flanker interference was observed under the 2-back condition in both the visual within-modality (VM) and audiovisual cross-modality (AVM) tasks. However, performance impairment emerged at a lower load (2-back) in the VM condition, whereas in the AVM condition, it only emerged at the highest load (3-back). Significant performance impairment in the AVM condition occurred at higher WM loads, suggesting that greater WM load is required to trigger interference. Event-related potential (ERP) results showed that N200 amplitudes increased significantly for incongruent flankers under the highest WM load (3-back) in the visual within-modality condition, reflecting greater inhibitory demands. In the cross-modality condition, enhanced N200 was not observed across all loads and even reversed at low load (1-back). Moreover, the results also showed that P300 amplitude increased with load in the within-modality condition but decreased in the cross-modality condition. Conclusions: These results demonstrated that the interaction between updating and inhibition is shaped by both WM load and sensory modality, further supporting a sensory modality-specific resource allocation mechanism. The cross-modality configurations may enable more efficient distribution of cognitive resources under high load, reducing interference between concurrent executive demands. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0883-2927 187 2025 Nitrogen distribution and nitrogen isotope fractionation in synthetic 2:1 phyllosilicates under hydrothermal conditions at 200 °C and saturated vapor pressure 106403 EN Jaeguk Jo Graduate School of Natural Science and Technology, Okayama University Toshiro Yamanaka Graduate School of Natural Science and Technology, Okayama University Youko Miyoshi Research Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST) Masaya Suzuki Research Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST) Yoshihiro Kuwahara Department of Environmental Changes, Faculty of Social and Cultural Studies, Kyushu University Isao Kadota Graduate School of Natural Science and Technology, Okayama University Hitoshi Chiba Graduate School of Natural Science and Technology, Okayama University Bum Han Lee Critical Minerals Research Center, Korea Institute of Geoscience & Mineral Resources (KIGAM) This study investigates nitrogen distribution and isotope fractionation within synthetic 2:1 phyllosilicates, simulating submarine hydrothermal environments at 200 °C and saturated vapor pressure. XRD and EDS results revealed the potential coexistence of multiple cations in the interlayer of synthetic 2:1 phyllosilicate, concurrently suggesting cation substitution in the tetrahedral and/or octahedral sheets. Meanwhile, the iron-enriched 25-5 sample exhibited restricted interlayer expansibility. NH4+ absorptions were identified in the NH4-stretching (3200–2800 cm−1) and NH4-bending (1450–1400 cm−1) regions, with wavenumber shifts indicating the influence of interlayer water removal. At pH 10.56, over 95% of nitrogen was released into the gas phase, while at pH 8.88, nitrogen proportions in the liquid and gas phases were comparable (average 48–49%). Experiments with iron at pH ∼8.80 showed that the nitrogen proportion in the gas phase (average 28%) was more than twofold lower than that in the liquid phase (average 68%). Equilibrium isotope fractionation factors indicated discernible preference for heavier nitrogen isotopes in the solid phase (αsolid-liquid = 1.009–1.021 and αsolid-gas = 1.011–1.027). The αliquid-gas range for sample 25–2 was 1.001–1.008, while that for the iron-enriched composite 25–5 was 0.997–1.010. Our experimental studies have confirmed that, in the absence of exchange interactions with external substances possessing different nitrogen isotope ratios, nitrogen isotope fractionation between ammonium and ammonia, controlled by variations in temperature and pH during mineralization, plays a crucial role in the variation of nitrogen isotope ratios. Additionally, we confirmed that metal-amines influence nitrogen isotope fractionation by modulating ammonia gas emission. These findings enhance our understanding of nitrogen cycling across the gas, liquid, and solid phases in submarine hydrothermal systems. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1463-9262 27 18 2025 Deoxygenative dual CO2 conversions: methylenation and switchable N-formylation/N-methylation of tryptamines 5359 5365 EN Kazuto Takaishi Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hajime Morishita Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kosuke Iwaki Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tadashi Ema Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University The unprecedented one-pot synthesis of N-formyl/N-methyltryptolines from tryptamines was achieved via phenylsilane-assisted deoxygenative dual CO2 conversions. Two CO2 molecules acted as different synthons and were converted into methylene and N-formyl/N-methyl groups. The CO2 reduction step was catalyzed by a pentanuclear zinc complex at atmospheric pressure under solvent-free conditions. The N-formyl/N-methyl products could be switched by changing the amount of phenylsilane, and the amounts of in situ generated bis(silyl)acetals and silyl formates were key to the chemoselectivity. Methylenation, N-formylation, and N-methylation proceeded via the Pictet–Spengler reaction, amine–acid condensation, and the Eschweiler–Clarke reaction, respectively. The CO2 reduction with phenylsilane could also be applied to the one-pot three-step synthesis of spiro[oxindole-pyrrolidine]s. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2574-0962 2025 Enhanced Charge-Transfer Kinetics Enabled by ZrO2–Based Dielectric Layers in Lithium-Ion Batteries EN Takashi Teranishi Graduate School of Natural Science and Technology, Okayama University Yusuke Higaki Graduate School of Natural Science and Technology, Okayama University Tomonori Imamura Graduate School of Natural Science and Technology, Okayama University Motoki Horibe Department of Advanced Ceramics, Nagoya Institute of Technology Shinya Kondo Department of Energy Engineering, Nagoya University Chinatsu Sasaoka R&D Laboratory, Nippon Denko Co., Ltd. Hikaru Hirabaru R&D Laboratory, Nippon Denko Co., Ltd. Shingo Katayama R&D Laboratory, Nippon Denko Co., Ltd. Masanobu Nakayama Department of Advanced Ceramics, Nagoya Institute of Technology Akira Kishimoto Graduate School of Natural Science and Technology, Okayama University The development of high-rate capability lithium-ion batteries (LIBs) requires suppression of charge-transfer resistance (RCT) at electrode–electrolyte interfaces. Here, zirconia-based dielectric oxides (MZ; M = Y, Gd, Sm, Er, etc.) were introduced onto LiCoO2 (LCO) surfaces as electronically and ionically insulating modifiers to accelerate interfacial ion transport. Electrochemical impedance spectroscopy showed that Y2O3 modified ZrO2 (YZ) decoration reduced RCT from 75.8 Ω in reference LCO to 38.3 Ω, accompanied by a 2.3-fold improvement in capacity retention at 20C. Density functional theory molecular dynamics (DFT–MD) simulations showed that solvated Li ions coordinate with surface oxygen atoms in discharging, and that adsorption energies are governed by local charge distributions determined by stabilizing cations. Optimal adsorption activity, and thus the lowest RCT, occurred when the surface charge corrugation was balanced. These findings provide design principles for dielectric interface engineering to enhance rate capability of LIBs. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2771-9316 2025 Photochemical Macrolactonization of Hydroxyaldehydes via C–H Bromination EN Sakura Kodaki Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Haru Ando Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1613-6810 2025 Atomic-Level Insights into Thermal Carbonization of Ethynyl-Containing Boron Compounds e13537 EN Kentaro Ohkura Research Institute for Interdisciplinary Science, Okayama University Satoshi Hayakawa Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Naoki Takahashi Graduate School of Environment Life Natural Science and Technology, Okayama University Ken Yamazaki Graduate School of Environment Life Natural Science and Technology, Okayama University Jun Kano Graduate School of Environment Life Natural Science and Technology, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University This study reports the design, synthesis, and characterization of boron-doped carbon (BDC) derived from a triethynylborane-pyridine complex. Triethynylborane is stabilized by coordination with pyridine, facilitating its synthesis and handling in ambient conditions. The complex is subjected to thermal treatment at various temperatures to form BDC. Powder XRD and single-crystal XRD analyses reveal that BDC prepared at 200 °C retains an ordered structure, while higher temperatures induce alkyne structural changes without significant weight or surface area alterations. Coin cells are assembled using BDC as the anode, demonstrating unique Li-ion and Na-ion storage properties distinct from graphite. These results suggest that the BDC reflects the precursor's crystal structure, enabling novel electrochemical behavior. These findings offer insight into the development of advanced BDC materials for energy storage applications. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2158-4001 2025 A Linear Search Algorithm for Resource Allocation in Frequency Domain Non-Orthogonal Multiple Access EN Satoshi Denno Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuto Ohba Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yafei Hou Faculty of Environmental, Life, Natural Science and Technology, Okayama University This paper proposes a linear search algorithm for resource allocation in frequency domain non-orthogonal multiple access based on the low-density signature (LDS). Although the proposed linear search enables the non-orthogonal multiple access to achieve superior transmission performance, the proposed linear search makes the resource allocation implemented with lower and fixed computational complexity. The performance of the non-orthogonal access based on the proposed linear search is evaluated by computer simulation. The proposed linear search algorithm makes the non-orthogonal multiple access achieve a gain of about 6 dB at the BER of 10–5 when the overloading ratio is set to 2. The complexity of the non-orthogonal access based on the proposed linear search algorithm is approximately half as much as that of the conventional low complexity resource allocation when the overloading ratio is 2, if the complexity is evaluated in terms of the number of additions. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Development of a synthetic method for terpene scaffolds via stereoselective construction of quaternary carbon centers EN Naochika MATSUMARU Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Structural insights into a citrate transporter that mediates aluminum tolerance EN TRAN NGUYEN THAO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Geochemical characterization of gaseous reservoirs in the enstatite-chondrite forming-region of the proto-solar nebula: Constraints from Li-isotope, O-isotope, and trace-element compositions in chondrule components EN TORII PHILIP DOUGLAS-SONG Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Development of a micro-organic matter identifier and its application to characterise insoluble organic matter in carbonaceous chondrite and Ryugu samples EN RAHUL KUMAR Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Synthesis of Indole Derivatives via Deoxygenative CO2 Conversions EN Sha LI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Design and Synthesis of Cholesterol 24-Hydroxylase Inhibitors Using 1,3-Oxazole as a Heme-Iron Binding Group EN Yoshiteru ITO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Development of a production method for biologically active globular proteins through chemical modification-based solubilization of denatured proteins EN Shuichiro KIMURA Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 サイドプランジ研削における研削温度の実験的検討とクーラント供給の最適化 EN Lingxiao Gao Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Lightweight Deep Learning-Based Intrusion Detection System for Deployment on Raspberry Pi EN MUHAMMAD BISRI MUSTHAFA Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Integrated Kerberos-Blockchain Authentication Framework for Securing Vehicular Ad-Hoc Network EN MAYA RAHAYU Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 A Blockchain-Based PGP Key Sharing Mechanism for Secure Email Communication EN MD. BIPLOB HOSSAIN Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 A Study of Indoor Navigation System Using Unity Game Engine and Smartphone EN EVIANITA DEWI FAJRIANTI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 A Study of Reference Paper Collection System Using Web Scraping and BERT Model EN INZALI NAING Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 銅による炭素−水素結合活性化を利用したアルケンの二官能基化反応 EN Yuichi YAMAMOTO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Coherence Generation in Atomic Cesium for Cosmic Dark Matter Detection EN JING WANG Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 The X-ray induced quenching of the thorium-229 isomer states in a CaF2 crystal host EN Ming Guan Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Functional-morphological relationships of vasopressin in the macaque neuroendocrine system EN Akito OTSUBO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Multimodal analysis of the Caenorhabditis elegans lipid molecular profile EN Sara Mandic Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 交代符号行列と数理物理モデルとの関係および組み合わせゲーム理論への応用 EN Toyokazu OMOTO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2072-6694 17 19 2025 Utility of Same-Modality, Cross-Domain Transfer Learning for Malignant Bone Tumor Detection on Radiographs: A Multi-Faceted Performance Comparison with a Scratch-Trained Model 3144 EN Joe Hasei Department of Medical Informatics and Clinical Support Technology Development, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ryuichi Nakahara Science of Functional Recovery and Reconstruction, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yujiro Otsuka Department of Radiology, Juntendo University School of Medicine Koichi Takeuchi Graduate School of Environmental, Life Natural Science and Technology, Okayama University Yusuke Nakamura Plusman LCC Kunihiro Ikuta Department of Orthopedic Surgery, Graduate School of Medicine, Nagoya University Shuhei Osaki Department of Musculoskeletal Oncology and Rehabilitation, National Cancer Center Hospital Hironari Tamiya Department of Musculoskeletal Oncology Service, Osaka International Cancer Institute, Shinji Miwa Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kanazawa University Shusa Ohshika Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine Shunji Nishimura Department of Orthopaedic Surgery, Kindai University Hospital Naoaki Kahara Department of Orthopedic Surgery, Mizushima Central Hospital Aki Yoshida Science of Functional Recovery and Reconstruction, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroya Kondo Science of Functional Recovery and Reconstruction, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Tomohiro Fujiwara Science of Functional Recovery and Reconstruction, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Toshiyuki Kunisada Science of Functional Recovery and Reconstruction, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Toshifumi Ozaki Science of Functional Recovery and Reconstruction, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background/Objectives: Developing high-performance artificial intelligence (AI) models for rare diseases like malignant bone tumors is limited by scarce annotated data. This study evaluates same-modality cross-domain transfer learning by comparing an AI model pretrained on chest radiographs with a model trained from scratch for detecting malignant bone tumors on knee radiographs. Methods: Two YOLOv5-based detectors differed only in initialization (transfer vs. scratch). Both were trained/validated on institutional data and tested on an independent external set of 743 radiographs (268 malignant, 475 normal). The primary outcome was AUC; prespecified operating points were high-sensitivity (≥0.90), high-specificity (≥0.90), and Youden-optimal. Secondary analyses included PR/F1, calibration (Brier, slope), and decision curve analysis (DCA). Results: AUC was similar (YOLO-TL 0.954 [95% CI 0.937–0.970] vs. YOLO-SC 0.961 [0.948–0.973]; DeLong p = 0.53). At the high-sensitivity point (both sensitivity = 0.903), YOLO-TL achieved higher specificity (0.903 vs. 0.867; McNemar p = 0.037) and PPV (0.840 vs. 0.793; bootstrap p = 0.030), reducing ~17 false positives among 475 negatives. At the high-specificity point (~0.902–0.903 for both), YOLO-TL showed higher sensitivity (0.798 vs. 0.764; p = 0.0077). At the Youden-optimal point, sensitivity favored YOLO-TL (0.914 vs. 0.892; p = 0.041) with a non-significant specificity difference. Conclusions: Transfer learning may not improve overall AUC but can enhance practical performance at clinically crucial thresholds. By maintaining high detection rates while reducing false positives, the transfer learning model offers superior clinical utility. Same-modality cross-domain transfer learning is an efficient strategy for developing robust AI systems for rare diseases, supporting tools more readily acceptable in real-world screening workflows. No potential conflict of interest relevant to this article was reported.

Japanese Society of Tribologists Acta Medica Okayama 1881-2198 20 3 2025 Water Lubrication of Polysiloxane-Containing Polyimide Coatings on Stainless Steel Substrates 124 129 EN Yuelin Fan Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tadashi Shiota Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuya Omiya Faculty of Environmental, Life, Natural Science and Technology, Okayama University Masahiro Fujii Faculty of Environmental, Life, Natural Science and Technology, Okayama University This study investigated the water-lubricated tribological properties of coatings made of a novel polysiloxane-containing polyimide (si-PI) material that was recently developed for the aerospace industry and can be diluted with the harmless and environmentally friendly ethanol or water. The si-PI coatings were deposited on stainless steel (JIS SUS304) substrates at curing temperatures ranging from 160°C to 275°C. Their water lubrication properties were measured by rubbing the coatings against each other in water at room temperature. The coatings exhibited lower friction than conventional polyimide materials, with a minimum friction coefficient of 0.04, which was lower than that of polytetrafluoroethylene (PTFE) measured under the same sliding conditions. Unlike the conventional polyimide, the coatings did not exhibit any obvious wear or damage. The results demonstrate that the si-PI coating is a promising low-friction and highly durable coating for water lubrication. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2399-3669 8 1 2025 Synthesis of thienoacenes by electrochemical double C–S cyclization using a halogen mediator 366 EN Koichi Mitsudo Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Takuya Nagahara Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nozomi Kataura Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuka Okamura Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Toki Yonezawa Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuri Tachibana Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nolan Soulié Faculty of Science and Engineering, Sorbonne Université Keisuke Shigemori Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroki Mandai Department of Pharmacy, Faculty of Pharmacy, Gifu University of Medical Science Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Thienoacenes are significant compounds as organic materials. One of the most efficient ways to synthesize thienoacenes is to form multiple C–S bonds in a single step. Because unprotected S–H bonds are easily oxidized to S–S bonds, S-Me protected substrates are commonly used for the purpose. However, their reactivity is insufficient, and one-step construction of multiple C–S bonds is still challenging. We herein report the electrochemical synthesis of thienoacenes from S-methoxymethyl (MOM)-protected diarylacetylenes. In the presence of Bu4NBr as a halogen mediator, electrochemical double C–S cyclization of diarylacetylenes bearing two MOM groups proceeded to afford [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives. While S-Me or S-p-methoxybenzyl (PMB)-protected diarylacetylenes did not afford BTBT, BTBT was selectively obtained when a substrate protected with S-MOM groups was used. The S-MOM protection strategy is also effective for the electrochemical synthesis of a more π-expanded thienoacene such as dibenzo[d,d′]thieno[3,2-b,4,5-b′]dithiophene (DBTDT). No potential conflict of interest relevant to this article was reported.

Institute of Electrical and Electronics Engineers (IEEE) Acta Medica Okayama 2169-3536 13 2025 Enhancing Protection Against Code Reuse Attacks on IoT Devices by Randomizing Function Addresses 185111 185124 EN Kazuma Saji Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Satoru Kobayashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Hideo Taniguchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Most Internet of Things (IoT) devices currently in use are vulnerable to code reuse attacks because manufacturers typically deploy the same firmware across all devices. This uniformity enables attackers to craft a single exploit that can compromise multiple devices. To mitigate this risk, we propose a firmware diversification approach that creates multiple executable files with varying software compositions. Our approach introduces two complementary techniques: Function Address Reordering (FAR), which randomizes the order of functions within object files during compilation, and Object Address Reordering (OAR), which permutes the linking order of object files in the final executable. These techniques collectively diversify firmware instances without altering runtime behavior, making executing code reuse attacks significantly more difficult. By deploying firmware with diverse executable files, it is possible to enhance security without altering device behavior. We evaluate the effectiveness and limitations of the proposed methods when integrated into actual IoT firmware, assessing their resilience to code reuse attacks, impact on runtime behavior, and compilation overhead. Experimental results demonstrate that FAR and OAR significantly reduce the success rate of return-oriented programming attacks while incurring minimal performance overhead. This study offers a scalable, hardware-independent defense against code reuse attacks that increases resilience without a significant performance overhead, rendering it practical for widespread adoption in various IoT applications. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 61 89 2025 The direct photochemical cross-esterification of alcohols via site-selective C–H bromination site-selective C–H bromination 17364 17367 EN Atsuya Miyamoto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University We have developed a direct photochemical cross-esterification of alcohols that proceeds via the in situ generation of acyl bromides. The C–H bond of a benzyl alcohol is selectively activated by a bromo source under light irradiation, enabling the cross-esterification to afford a variety of functionalized esters. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2352-4928 50 2026 Effects of grain size and crystal orientation on tensile properties of pure titanium thin wires 114240 EN Junji Sakamoto Faculty of Environmental, Life, Natural Science and Technology, Okayama University Naoya Tada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takeshi Uemori Faculty of Environmental, Life, Natural Science and Technology, Okayama University To clarify the effects of the grain size and crystal orientation on the tensile properties of pure titanium thin wires, tensile and stepwise tensile tests were conducted on pure titanium wires with diameters of approximately 180 μm and different average grain sizes (52, 37, 23, and 3.8 μm). When the grain size was large, the fracture strain was significantly smaller, the variation in tensile strength was larger, and the grain size threshold for such properties was a grain-size ratio to wire diameter of 0.13 or greater. For larger grain sizes, the slip system with the highest modified Schmid factor (MSF), which is the Schmid factor divided by the critical resolved shear stress of each slip system, was activated in all 15 grains whereas for smaller grain sizes, the percentage of slip systems activated with the highest MSF was slightly lower. In addition, the fracture location in a thin wire with larger grain sizes was highly correlated with the average MSF of the grains in the cross-section. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1939-5981 2025 Effect of Repeated Gravity Casting on the Microstructure and Mechanical Properties of 6061 Aluminum Alloy EN Mitsuhiro Okayasu Department of Mechanical Systems and Engineering, Okayama University Shouei Makino Department of Mechanical Systems and Engineering, Okayama University Shota Nakagawa Research & Development Center, Marketing & Technology Division, UACJ Corporation Shuhei Takeuchi Department of Mechanical Systems and Engineering, Okayama University Yoshifumi Shinzato Research & Development Center, Marketing & Technology Division, UACJ Corporation Tadashi Minoda Research & Development Center, Marketing & Technology Division, UACJ Corporation Naotaka Ohtsuka Research & Development Center, Marketing & Technology Division, UACJ Corporation This study systematically investigates the effects of repeated gravity casting on the microstructure and mechanical properties of 6061 aluminum alloy. With an increasing number of casting cycles from one to ten, grain coarsening and a decrease in dislocation density were observed, mainly due to the significant depletion of magnesium from 1.03 to 0.01% and titanium from 0.009 to 0.005%. These microstructural changes led to a decrease in solid-solution strengthening and grain-boundary strengthening, resulting in a 30% reduction in tensile strength, while ductility increased by about three times. Moreover, work hardening decreased with increasing the casting cycle, which can be attributed not only to the microstructural changes but also to the increase in stacking fault energy (SFE) associated with compositional evolution. From the transmission electron microscopy (TEM) observations, in the 1-cycle sample, Mg2Si precipitates were finely dispersed and a high amount of Mg element in the matrix, resulting in significant dislocation accumulation, whereas the 10-cycle sample exhibited weaker dislocation tangling. These microstructural evolutions provide insight into the degradation of mechanical performance in aluminum alloys subjected to multiple casting processes. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2510-1560 2025 Enhanced electric power generation in PZT ceramics via stress control EN Mitsuhiro Okayasu Department of Mechanical Systems and Engineering, Okayama University Itsuki Shimazu Department of Mechanical Systems and Engineering, Okayama University This study aimed to enhance the electric power generation of lead zirconate titanate piezoelectric (PZT) ceramics by optimizing stress distribution. Specifically, it focused on applying high stress over a broad area of the PZT ceramic to induce shape deformation in the PZT plate. Pre-straining the PZT plate into an arch shape improved voltage generation, reaching its peak at a maximum deflection of 0.04 mm due to the expanded and intensified stress distribution. However, exceeding this deflection threshold led to a decline in voltage output due to material degradation, including crack formation and 90° domain switching. Finite element analysis confirmed that the increased stress distribution in the pre-strained PZT plate contributed to higher voltage output. Additionally, electron backscatter diffraction analysis revealed that at higher pre-strains (deflection of 0.08 mm), 90°domain switching occurred, resulting in increased internal strain and potential crack formation. Experimental investigations using bulk PZT rods further demonstrated that moderate pre-straining effectively enhanced voltage output. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1939-5981 2025 Upgrading Recycle Technology for Iron Removal in ADC12 Alloy Using Gravity and Magnetic Force EN M. Okayasu Department of Mechanical Systems and Engineering, Okayama University S. Takeuchi Department of Mechanical Systems and Engineering, Okayama University M. Syahid Department of Mechanical Engineering, Hasanuddin University T. Ikeda Department of Mechanical Systems and Engineering, Okayama University As there is a technical issue to remove iron elements during aluminum recycling process, an attempt was made to evaluate the effectiveness of magnetic and gravitational separation methods for removing iron from Al-Si-Cu alloy (ADC12). A rare-earth samarium–cobalt (SmCo) magnet was employed during the solidification process to attract Fe-rich eutectic structures. The microstructural analysis revealed that block-like Fe-Cr-Si-based phases formed preferentially near the magnet and at the bottom of the crucible, suggesting that magnetic and gravity attraction contributed to the localized segregation of these phases. However, other Fe-based phases, including Fe-Si-based ones, are not strongly affected by magnet. Additionally, prolonged heating in the solid–liquid coexistence (SLC) region at 577 °C for 10 h led to the settling of a largely grown Fe-Cr-Si-rich crystal at the bottom of the crucible due to gravity. Other structures, such as Si-rich eutectic phases, were not influenced by gravity, which may be caused by the low density of Si compared to Fe one. From this approach, combining magnetic attraction and gravitational settling is a promising method to promote the removal of iron impurities from aluminum alloys. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0361-5235 54 7 2025 Electric Power Generation of PZT Piezoelectric Ceramics Using Both Direct and Inverse Piezoelectric Effects 5143 5150 EN Mitsuhiro Okayasu Department of Mechanical Systems and Engineering, Okayama University Itsuki Shimazu Department of Mechanical Systems and Engineering, Okayama University The power generation characteristics of lead zirconate titanate (PZT) piezoelectric ceramics (E-PZT) were experimentally investigated using a specialized PZT system which utilizes both the direct and inverse piezoelectric effects inherent to PZT materials. Specifically, electric voltage was generated from the vibration of E-PZT through the inverse piezoelectric effect, induced by mechanical energy transferred from the vibration of a PZT piezoelectric ceramic plate, such as a buzzer (B-PZT). In this system, an insulating material was placed between the B-PZT and E-PZT plates to address the electrical conductivity of the PZT ceramic. Various insulating materials with different thicknesses and different hardness were prepared. Additionally, the PZT systems were mounted in several distinct configurations to evaluate their power generation performance: a fully fixed around the PZT plate and a free-hanging setup. The influence of insulation materials and mounting conditions on electrical output was analyzed at various loading conditions, e.g., loading value and frequency. The results demonstrated that the generated electric voltage decreased with increasing insulation thickness and hardness, suggesting that thinner and softer insulating materials enhance output voltage. Conversely, when the PZT system was securely fixed around the PZT plate with an appropriate fixture, a higher and more stable electric voltage was generated. The voltage generated also varied by the loading condition, which is related to the strain value of the E-PZT plate, demonstrating a linear relationship between the strain and the output voltage. Notably, the strain was significantly influenced by resonant frequencies, which played a crucial role in achieving higher voltage outputs. Based on these experimental results, two power generation systems have been proposed. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 1096-4959 281 2026 N-terminal domains and site-specific glycosylation regulate the secretion of avian melanocortin inverse agonists, agouti signaling protein (ASIP) and agouti-related protein (AGRP) 111174 EN Hibiki Fukuchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Ryoya Watanabe Graduate School of Natural Science and Technology, Okayama University Yuna Iida Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Saya Nakano Graduate School of Natural Science and Technology, Okayama University Aya Mizutani Graduate School of Natural Science and Technology, Okayama University Tatsuhiko Abo Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Sayaka Aizawa Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Sakae Takeuchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Agouti signaling protein (ASIP) and agouti-related protein (AGRP) are paralogous inverse agonists of melanocortin receptors with distinct physiological roles, but their structural and biochemical properties in birds remain poorly understood. Here, we characterized chicken ASIP and AGRP proteins. Analysis of available sequences revealed that a motif resembling the mammalian proprotein convertase 1/3 (PC1/3, also known as PCSK1) cleavage site is conserved across a broad range of avian orders, but Western blot analysis of transfected Chinese hamster ovary (CHO-K1) cells and chicken hypothalamus detected no cleavage, suggesting that avian AGRP may not be post-translationally processed at this site. Chicken ASIP mRNA contains an in-frame upstream ATG (uATG) and a putative N-linked glycosylation site at Asn-42, both conserved across multiple avian orders. Overexpression in CHO-K1 cells showed that ASIP translated from either ATG produces a mature protein of the same size that is N-glycosylated at Asn-42 and exhibits markedly lower secretion efficiency than AGRP. Domain-swapping experiments revealed that the N-terminal domain reduces secretion, whereas a naturally occurring ASIP-b variant with an additional N-glycan at Asn-47 shows enhanced secretion. Proteasome inhibition increased intracellular ASIP, and endoglycosidase H (Endo H) sensitivity indicated endoplasmic reticulum (ER) retention, suggesting that the N-terminal domain limits secretion via ER-associated proteasomal degradation. These findings reveal species-specific post-translational regulation of avian melanocortin inverse agonists, in which N-terminal features and site-specific N-glycosylation determine secretion efficiency, likely contributing to their distinct roles in pigmentation and hypothalamic energy balance. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1532-0626 37 27-28 2025 Algebraic Connectivity Maximizing Regular Graphs: Special Case Analysis and Depth‐First Search e70357 EN Masashi Kurahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Najd Salaani Polytech Sorbonne, Sorbonne University Tsuyoshi Migita Faculty of Environmental, Life, Natural Science and Technology, Okayama University Norikazu Takahashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University The algebraic connectivity is an indicator of how well connected a graph is. It also characterizes the convergence speed of some dynamic processes over networks. In this paper, taking into account that homogeneous networks are modeled as regular graphs, we tackle the following problem: given a pair (𝑛, 𝑘) of positive integers such that 𝑘 is less than 𝑛 and kn is an even number, find a 𝑘-regular graph with 𝑛 vertices that have the maximum algebraic connectivity. We first consider some special cases and derive solutions through theoretical analysis. We next present depth-first search algorithms for solving the problem, which reduce the search space by making use of some known properties of the regular graph and the algebraic connectivity.We also show the results of execution of the proposed algorithms for the values of 𝑛 up to 12. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1439-0108 2025 Coupling effects of biochar and sediment microbial fuel cells on CH4 and CO2 emissions from straw-amended paddy soil EN Adhena Tesfau Bekele Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Morihiro Maeda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nozomi Nakahara Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Ayumi Hashiguchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroaki Somura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Satoshi Akao Faculty of Science and Engineering, Doshisha University Chiyu Nakano Department of Comprehensive Technical Solutions, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Purpose The independent incorporation of biochar and sediment microbial fuel cells (SMFCs) into paddy soil has been shown to reduce methane (CH4) emissions. However, the application of rice straw into paddy soil enhances the availability of labile carbon that stimulates methanogen growth, counteracting the mitigation effects of both methods. This study, therefore, aimed to investigate the effect of coupling biochar and SMFC on CH4 and CO2 emissions from straw-amended paddy soil.<br> Materials and methods Single chamber SMFC setups constructed using acrylic columns (height, 25 cm; inner diameter, 9 cm) with six treatments were established using soil amended with 0% (0BC), 1% (1BC), and 2% (2BC) biochar: with and without SMFC conditions. Stainless steel mesh (15 × 3 cm) and graphite felt (6 × 5 cm) were used as anode and cathode materials, respectively.<br> Results Cumulative emission of CH4 in the 0BC treatment with SMFC was 39% less than in that without SMFC. Biochar addition and SMFC operation together further reduced CH4 emission by 57% and 60% in 1BC and 2BC treatments, respectively, compared to that in the 0BC treatment without SMFC operation. The relative abundance of microbial communities indicated methane-oxidizing bacteria were enriched in the presence of biochar and hydrogenotrophic Methanoregula were suppressed by SMFC operation. This suggested that SMFC mainly inhibited CH4 production by outcompeting hydrogenotrophic archaea.<br> Conclusion The use of biochar made from leftover rice straw has an interactive effect on SMFC operation and both methods can be used to reduce CH4 emission from straw-amended paddy soil. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 1882-0778 18 10 2025 Multichannel topological elastic waveguide in a multilayer Kagome phononic crystal 107001 EN Yusuke Hata Department of Electrical and Electronic Engineering, Okayama University Kenji Tsuruta Department of Electrical and Electronic Engineering, Okayama University By examining the geometric characteristics of various boundaries formed within the Kagome phononic lattice and vertically stacking the lattices, we designed an elastic waveguide that enables selective propagation of topologically protected edge modes across layers in a bilayer system. This layer-selective transmission is manifested as polarized boundary modes that appear in phononic dispersions of the systems incorporating the bridge, zigzag, and armchair boundaries. We numerically demonstrated that efficient elastic layer converters and splitters can be designed, thereby paving the way for the practical development of three-dimensional elastic-wave devices. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1086-9379 2025 The effect of pressure on dihedral angle between liquid Fe‐S and orthopyroxene: Implication for percolative core formation in planetesimals and planetary embryos EN Takumi Miura Department of Earth and Space Science, Osaka University Hidenori Terasaki Department of Earth Sciences, Okayama University Hyu Takaki Department of Earth Sciences, Okayama University Kotaro Kobayashi Department of Earth Sciences, Okayama University Geoffrey David Bromiley School of Geosciences, The University of Edinburgh Takashi Yoshino Institute for Planetary Materials, Okayama University During precursor stages of planet formation, many planetesimals and planetary embryos are considered to have differentiated, forming an iron-alloy core and silicate mantle. Percolation of liquid iron-alloy in solid silicates is one of the major possible differentiation processes in these small bodies. Based on the dihedral angles between Fe-S melts and olivine, a criterion for determining whether melt can percolate through a solid, it has been reported that Fe-S melt can percolate through olivine matrices below 3 GPa in an oxidized environment. However, the dihedral angle between Fe-S melts and orthopyroxene (opx), the second most abundant mineral in the mantles of small bodies, has not yet been determined. In this study, high-pressure and high-temperature experiments were conducted under the conditions of planetesimal and planetary embryo interiors, 0.5–5.0 GPa, to determine the effect of pressure on the dihedral angle between Fe-S melts and opx. Dihedral angles tend to increase with pressure, although the pressure dependence is markedly reduced above 4 GPa. The dihedral angle is below the percolation threshold of 60° at pressures below 1.0–1.5 GPa, indicating that percolative core formation is possible in opx-rich interiors of bodies where internal pressures are lower than 1.0–1.5 GPa. The oxygen content of Fe-S melt decreases with increasing pressure. High oxygen contents in Fe-S melt reduce interfacial tension between Fe-S melt and opx, resulting in reduced dihedral angles at low pressure. Combined with previous results for dihedral angle variation of the olivine/Fe-S system, percolative core formation possibly occurs throughout bodies up to a radius of 1340 km for an olivine-dominated mantle, and up to 770 km for an opx-dominated mantle, in the case of S-rich cores segregating under relatively oxidizing conditions. For mantles of small bodies in which abundant olivine and opx coexist, the mineral with the largest volume fraction and/or smallest grain size will allow formation of interconnected mineral channels, and, therefore, the wetting property of this mineral determines the wettability of the melt, that is, controls core formation. No potential conflict of interest relevant to this article was reported.

Springer Nature Singapore Acta Medica Okayama 1865-0929 2025 Evaluation of a Startup Program Identification for Efficient and Accurate IoT Security Investigations 417 431 EN Yuta Shimamoto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Jiratchaya Phinyodom School of Engineering, Okayama University Ryota Yoshimoto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyuki Uekawa NTT Social Informatics Laboratories Mitsuaki Akiyama NTT Social Informatics Laboratories Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Not all file in firmware are executed while using Internet of Things (IoT) devices and hundreds to approximately a thousand executable and linkable format files exist in one firmware. Therefore, security investigations without prioritization may lead to investigate programs that are not executed while using IoT devices first. This has resulted in inefficient security investigations. To perform efficient security investigations, we proposed a method that can identify programs executed during the startup process. However, only two firmware were used for the evaluation which can only evaluate one of the two startup sequences in the OpenWrt-based firmware. In addition, security investigations to validate whether the proposed method addresses the problem of inefficient security investigations were limited to OpenWrt-based firmware. In this study, we use more firmware data for evaluation and validation. We use nine firmware not used in previous studies including startup methods that have not previously been used for evaluation. In addition, we increase the number of firmware used for validation to 225. The evaluation results demonstrate that the proposed method can identify with only few false positives. The validation demonstrates that efficiency can be improved and prioritizing investigations by considering the proposed method result is worthwhile. No potential conflict of interest relevant to this article was reported.

Japan Institute of Metals Acta Medica Okayama 0021-4876 89 11 2025 Ti-18Nb-xAl合金の構成相と材料特性に及ぼすAl添加量の影響 337 343 EN Yoshikazu Mantani Department of Materials Science and Engineering, National Institute of Technology (KOSEN), Suzuka College Yoshito Takemoto Faculty of Environmental, Life, Natural Science and Technology, Okayama University The Ti-18mass%Nb alloy with a quenched α” martensitic structure exhibited a high damping capacity. However, there are issues such as lower strength than annealed α+β structure and decreasing damping capacity due to heating until 400 K. Therefore, in this study, to address these issues, we investigated the effect of Al addition on the constituent phases and material properties of Ti-18Nb-xAl alloys. The crystal structure was determined by examining the lattice constant and unit volume using X-ray diffraction, and optical microscopy was also performed. The material properties were investigated by Vickers hardness, Young’s modulus, internal friction, tensile tests, and DSC measurements. Vickers hardness and tensile strength increased with increasing Al content. This is thought to be due to the combined effects of the refinement of the microstructure and solid-solution strengthening due to Al addition. The Young’s modulus increased slightly from 0Al to 1Al, but increased significantly to 4Al. Internal friction was highest for 0Al and decreased for 4Al, whereas 7Al showed a higher value than 1Al. In the DSC heating curves, there was a decrease in the exothermic peak starting temperature and an increase in the phase-transformation heat with the addition of Al, except for 1Al. It was suggested that these changes in Ti-18Nb-xAl alloys were influenced by the structure of the quenched α” phase, texture, and pseudoelasticity or phase transformation by deformation. No potential conflict of interest relevant to this article was reported.

Informa UK Limited Acta Medica Okayama 0960-3409 2025 Creep damage parameters based on the distribution of cavities on grain boundaries EN Naoya Tada Faculty of Environmental, Life, Natural Science and Technology, Okayama University When polycrystalline heat-resistant steels are subjected to static or cyclic loading at high temperatures, they can exhibit various fracture modes and processes. This paper begins by outlining representative methods for life assessment under creep-dominated conditions. It then discusses the fracture processes and the underlying mechanisms. Under creep-dominated conditions, the initiation and growth of cavities serve as the primary form of material damage, making their quantitative assessment essential. Several parameters have been proposed to evaluate cavity distributions quantitatively. However, the relationship between these parameters and the actual cavity distribution in materials, as well as their physical significance, has remained unclear. In this study, a simple cavity distribution model was employed to clarify these issues. The results suggest that the area fraction of cavities is an appropriate damage evaluation parameter for transgranular fracture, while the fraction of cavities on grain boundary line is suitable for intergranular fracture. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0952-1976 150 2025 Surrogate-assisted motion planning and layout design of robotic cellular manufacturing systems 110530 EN Tomoya Kawabe Graduate School of Environmental, Life and Natural Science and Technology, Okayama University Tatsushi Nishi Graduate School of Environmental, Life and Natural Science and Technology, Okayama University Ziang Liu Graduate School of Environmental, Life and Natural Science and Technology, Okayama University Tomofumi Fujiwara Graduate School of Environmental, Life and Natural Science and Technology, Okayama University A surrogate-assisted multi-objective evolutionary algorithm is proposed for simultaneous optimization of robot motion planning and layout design in robotic cellular manufacturing systems. A sequence-pair is used to represent the layout of components in a robotic cell to avoid overlapping in the evolutionary computation. The robot motion planning with Rapidly exploring Random Trees Star (RRT*) is applied to compute the total operation time of a robot arm for each layout. Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used to minimize the total required layout area and the operation time for a robot arm. The proposed surrogate model can estimate the robot’s operation time with 98% of accuracy without explicit computations of the motion planning algorithm. The experimental results with a physical 6 Degree of Freedom (DOF) manipulator show that the total computation time is approximately 1/400, significantly shorter than the conventional methods. No potential conflict of interest relevant to this article was reported.

Japan Society on Water Environment Acta Medica Okayama 1348-2165 23 5 2025 Biochar-amended Sediment Microbial Fuel Cells for Water Quality Improvement in Intensive and Extensive Pond Drainages in Central Vietnam 234 249 EN Uyen Tu Nguyen Graduate School of Environmental and Life Science, Okayama University Morihiro Maeda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroaki Somura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nozomi Nakahara Department of Comprehensive Technical Solutions, Okayama University Gamamada Liyanage Erandi Priyangika Perera Graduate School of Environmental and Life Science, Okayama University Chiyu Nakano Graduate School of Environmental and Life Science, Okayama University Huu Tien Le Department of Education, Science and Technology Quang Tri Branch, Hue University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University The use of nutrient-rich feed in shrimp farming in Central Vietnam has led to high nitrogen (N) and phosphorus (P) contents in the pond sediment. The objectives of the study were to assess the effectiveness of biochar-sediment microbial fuel cells (BC-SMFCs) in suppressing P and N release from two types of sediment in intensive (Int) and extensive (Ext) pond drainages in Central Vietnam. Single chamber SMFCs were set up and operated under open or closed-circuit (no SMFC or SMFC) conditions. Coconut shell biochar (BC) was amended to sediments at 1%. For Int-sediment, total phosphorus (TP) release was reduced by no BC-SMFCs through co-precipitation with Fe. On the other hand, BC-SMFCs did not suppress TP release because P was released from BC and organic matter decomposition was enhanced in the sediment. Application of BC enhanced organic N mineralization in the sediment. Nitrification and denitrification occurred in the overlying water, reducing mineral N concentrations. For Ext-sediment, BC addition and SMFC conditions did not affect TP and total nitrogen (TN) release because of low initial organic matter content, and less reductive condition. Our study suggested that the effect of SMFCs was masked by BC which released more P from Int-sediment to the water. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0921-8831 36 10 2025 Evaluating the effects of electrolytes on the interaction forces between alumina surfaces in polyacrylic acid solutions using atomic force microscopy 105028 EN Naoto Kishimoto Graduate School of Natural Science and Technology, Okayama University Ryota Kaji Faculty of Science and Engineering, Doshisha University Katsumi Tsuchiya Faculty of Science and Engineering, Doshisha University Koreyoshi Imamura Graduate School of Natural Science and Technology, Okayama University Naoyuki Ishida Faculty of Science and Engineering, Doshisha University Evaluation and control of ceramic slurry at the microscopic level are critical to ensure consistent quality in manufactured ceramics. Notably, metal ions such as Mg2+ and Al3+ are common in ceramic slurries and significantly influence the stability of particle. This study applied atomic force microscopy to investigate the interaction forces between alumina particle surfaces in the presence of different concentrations of three metal ions and polyacrylic acid (PAA), a widely used dispersant.<br> The attractive forces observed at low PAA concentrations were attributed to polymer bridging between alumina surfaces, whereas the repulsive forces observed at high PAA concentrations were attributed to the domination of steric repulsion between adsorbed PAA molecules. The presence of multivalent metal ions, such as Mg2+ and Al3+, modulated these interactions; an increasing ion valence induced a transition from repulsive to attractive force, primarily owing to electrostatic screening, which caused conformational collapse of the PAA chains and diminished the range of steric repulsion. Similarly, increasing the concentration of these metal ions decreased the range of repulsive forces, eventually resulting in a net attraction driven by the same electrostatic and polymer conformation mechanisms. Notably, the addition of 0.1 M AlCl3 produced an anomalous long-range attraction between surfaces that could not be explained by conventional mechanisms, such as polymer bridging or electrostatic interactions between charge domains. No potential conflict of interest relevant to this article was reported.

Frontiers Media SA Acta Medica Okayama 1664-462X 16 2025 The response to thermospermine is fine-tuned by the balance between SAC51 and LHW family proteins in Arabidopsis thaliana EN Yao Xu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Mitsuru Saraumi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tomohiko Toyoshima Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyasu Motose Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taku Takahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Thermospermine negatively regulates xylem formation. In Arabidopsis, SAC51 and SACL3, members of the SAC51 gene family encoding basic loop-helix-loop (bHLH) proteins play a key role in this regulation. These mRNAs contain an upstream open-reading-frame (uORF) that is highly conserved across species, and its inhibitory effect on the main ORF translation is alleviated by thermospermine. A double knockout of SAC51 and SACL3 results in thermospermine insensitivity at high concentrations that normally inhibit xylem formation and shoot growth in the wild type. Conversely, uORF mutants of SAC51, SACL3, and SACL1 suppress the excessive xylem formation and dwarf phenotype of acl5, a mutant defective in thermospermine biosynthesis. In this study, we generated genome-edited uORF mutants of SACL2 and confirmed that they partially recover the acl5 phenotype. All uORF mutants exhibited increased sensitivity to thermospermine. SACL3 represses the function of LHW, a key bHLH transcription factor required for xylem proliferation, through direct interaction. We found that the lhw mutant is also hypersensitive to thermospermine, while this sensitivity was suppressed by the sac51 sacl3 double knockout. Yeast two-hybrid assays demonstrated that all four SAC51 family members interact with LHW and its family members. These findings suggest that overaccumulation of SAC51 family proteins leads to thermospermine hypersensitivity by repressing the function of LHW family proteins, whose activity must be fine-tuned to ensure proper xylem development. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0960-7412 123 5 2025 RNA processing/modifying enzymes play key roles in the response to thermospermine in Arabidopsis thaliana e70476 EN Mitsuru Saraumi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Takahiro Tanaka Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Daiki Koyama Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yoshitaka Nishi Graduate School of Engineering, Kyushu Sangyo University Yoshihiro Takahashi Department of Life Science, Faculty of Life Science, Kyushu Sangyo University Hiroyasu Motose Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taku Takahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Thermospermine is involved in negative regulation of xylem differentiation by enhancing the translation of mRNAs of the SAC51 gene family in Arabidopsis (Arabidopsis thaliana). These mRNAs contain conserved upstream open reading frames (uORFs) that interfere with the translation of the main ORF. To investigate the mechanism by which thermospermine acts in this process, we isolated mutants insensitive to thermospermine, named ‘its’. We show that the four genes responsible for these mutants, its1 to its4, encode: (i) a homolog of SPOUT RNA methyltransferase, (ii) an rRNA pseudouridine synthase CBF5/NAP57, (iii) a putative spliceosome disassembly factor STIPL1/NTR1, and (iv) a plant-specific RNA-binding protein PHIP1. These four mutants were found to have much higher levels of thermospermine than the wild-type. While all these mutants except its1 appear almost normal, they enhance the dwarf phenotype of a mutant of ACL5, which encodes thermospermine synthase, resulting in tiny plants resembling a double knockout of ACL5 and SACL3, a member of the SAC51 family. Reporter assays revealed that GUS activity from the CaMV 35S promoter-SAC51 5′-GUS fusion construct was significantly reduced in its1 and its4 or not affected in its2 and its3, while it was slightly increased in its1, its3, and its4, or not changed in its2 by thermospermine. These findings underscore the critical role of RNA processing and modification in the thermospermine-dependent translational regulation of uORF-containing transcripts. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0167-6903 105 4 2025 Effect of environmental conditions on seed germination and seedling growth in Cuscuta campestris 1157 1167 EN Koki Nagao Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taku Takahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Ryusuke Yokoyama Graduate School of Life Sciences, Tohoku University Dodder (Cuscuta) is an obligate parasitic plant that cannot survive without a host and causes significant damage to crop yields. To understand its growth characteristics before parasitism, we examined the effects of environmental conditions on seed germination and seedling growth in Cuscuta campestris Yunck. Among various factors, we focused on the effects of light, pH, temperature, sugars, salts, hormones, amino acids and polyamines on seeds sown on agar plates. Regarding the effect of light on germination, far-red light was preferable rather than red light and the reversible response of seeds to red and far-red light was confirmed, implicating a phytochrome-mediated signaling pathway opposite to that in many seed plants. Among the amino acids, aspartic acid and alanine had a promotive effect, while histidine had an inhibitory effect on germination. We further found that, in addition to gibberellic acid, methyl jasmonate stimulated both germination and shoot elongation. While 2,4-D extended the viability of trichomes around the root cap, kinetin induced the formation of scale leaves on the shoot and undifferentiated cell clusters at the base of the shoot and root tip. Real-time reverse transcriptase PCR (RT-PCR) experiments confirmed that the expression of a putative RbcS gene for photosynthesis showed no response to light, whereas that of a Phytochrome A homolog increased in the dark. Our results indicate that some of the molecular mechanisms involved in responding to light and hormone signals are uniquely modified in dodder seedlings, providing clues for understanding the survival strategy of parasitic plants. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0957-4522 36 1 2024 Optical bandgap tuning in SnO2–MoS2 nanocomposites: manipulating the mass of SnO2 and MoS2 using sonochemical solution mixing 6 EN Chinkhai Ong School of Engineering and Physical Sciences, Heriot-Watt University Malaysia Weng Nam Lee Heriot-Watt Global College, Heriot-Watt University Malaysia Yee Seng Tan Sunway Biofunctional Molecules Discovery Centre, School of Medical and Life Sciences, Sunway University Patrik Ohberg School of Engineering and Physical Sciences, Institute of Photonics and Quantum Sciences, Heriot-Watt University Yasuhiko Hayashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takeshi Nishikawa Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuenkiat Yap Heriot-Watt Global College, Heriot-Watt University Malaysia This study investigates controlled optical bandgap tuning through precise adjustment of the SnO2 and MoS2 mass in nanocomposites. A sonochemical solution mixing method, coupled with bath sonication, is employed for the preparation of SnO2–MoS2 nanocomposite. This approach allows for comprehensive characterization using UV–Vis FTIR, XRD, EDX, Raman spectroscopies, and FESEM, providing insights into morphology, chemical, and optical properties. Increasing the SnO2 mass leads to a linear decrease in the optical bandgap energy, from 3.0 to 1.7 eV. Similarly, increasing the MoS2 mass also results in a decrease in the optical bandgap energy, with a limitation of around 2.01 eV. This work demonstrates superior control over optical bandgap by manipulating the SnO2 mass compared to MoS2, highlighting the complexities introduced by MoS2 2D nanosheets during sonication. These findings hold significant value for optoelectronic applications, emphasizing enhanced control of optical bandgap through systematic mass manipulation. No potential conflict of interest relevant to this article was reported.

Informa UK Limited Acta Medica Okayama 0003-2719 58 2 2024 Influence of Dilution Upon the Ultraviolet-Visible Peak Absorbance and Optical Bandgap Estimation of Tin(IV) Oxide and Tin(IV) Oxide-Molybdenum(IV) Sulfide Solutions 196 212 EN Chin Khai Ong School of Engineering and Physical Sciences, Heriot-Watt University Malaysia Weng Nam Lee Heriot-Watt Global College, Heriot-Watt University Malaysia Mohammad Khalid Sunway Centre for Electrochemical Energy and Sustainable Technology (SCEEST), School of Engineering and Technology, Sunway University Muhammad Amirul Aizat Mohd Abdah Sunway Centre for Electrochemical Energy and Sustainable Technology (SCEEST), School of Engineering and Technology, Sunway University Patrik Ohberg Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University Ling Hong Lim Heriot-Watt Global College, Heriot-Watt University Malaysia Yasuhiko Hayashi Graduate School of Natural Science and Technology, Faculty of Engineering, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Faculty of Engineering, Okayama University Yuenkiat Yap Heriot-Watt Global College, Heriot-Watt University Malaysia The study investigated the constraints associated with the dilution technique in determining the optical bandgap of nanoparticle dispersion and modified nanocomposites, utilizing ultraviolet-visible absorbance spectra and Tauc plot analysis. A case study involving SnO2 dispersion and SnO2-MoS2 nanocomposite solutions, prepared through the direct solution mixing method, was conducted to assess the implications of dilution upon the absorbance spectra and bandgap estimation. The results emphasize the considerable impact of the dilution technique on the measured optical bandgap, demonstrating that higher dilution factors lead to shift in bandgap values. Furthermore, the study highlights that dilution can induce variations in the average nanoparticle sizes due to agglomeration, thereby influencing bandgap estimation. In the context of nanocomposites, the interaction between SnO2 nanoparticles and exfoliated MoS2 nanosheets diminishes with increasing dilution, leading to the estimated optical bandgap being primarily attributable to SnO2 nanoparticles alone. These observations underscore the necessity for caution when employing the dilution technique for bandgap estimation in nanoparticles dispersion and nanocomposites, offering valuable insights for researchers and practitioners in the field. No potential conflict of interest relevant to this article was reported.

Fuji Technology Press Ltd. Acta Medica Okayama 1883-8022 19 5 2025 Study on an Effective Coolant Supply Method in the Side Plunge Grinding Process 939 948 EN Lingxiao Gao Graduate School of Natural Science and Technology, Okayama University Taichi Fujimoto Graduate School of Natural Science and Technology, Okayama University Hiroyuki Kodama Faculty of Environmental, Life, Natural Science and Technology, Okayama University Kazuhito Ohashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Grinding is widely used for finishing components with journal and thrust surfaces, such as crankshafts. Side-plunge grinding enables the simultaneous finishing of thrust and cylindrical surfaces in a single plunge. However, compared to cylindrical grinding, it involves a larger contact area between the grinding wheel and the workpiece, leading to increased heat generation. In particular, poor coolant penetration near internal corners can degrade surface quality, potentially causing stress concentrations and cracks. To enhance coolant effectiveness in side-plunge grinding, this study installs a high-pressure nozzle that supplies coolant from the side of the grinding wheel. The effectiveness of this setup is experimentally verified. Additionally, the distribution of coolant flow within the contact area between the grinding wheel and the workpiece is measured to determine the optimal nozzle position for efficient coolant delivery. The nozzle’s performance is evaluated by measuring the workpiece surface temperature using a wire/workpiece thermocouple, the amount of coolant discharged from the grinding wheel, and the residual stress distribution. The results show that coolant penetrates the grinding wheel and effectively reaches the grinding zone, enhancing the cooling effect. This study clarifies the relationship between effective coolant supply and the position of the side nozzle. Considering physical constraints, such as potential interference during grinding, the optimal nozzle location is as close as possible to both the edge of the grinding wheel and the workpiece. This positioning ensures maximum coolant delivery, reduces grinding temperature, and helps suppress drastic variations in residual stress. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2050-7488 13 35 2025 Thermally polymerizable phthalocyanine realizes a metal–nitrogen-doped carbon material featuring a defined single-atom catalyst motif with CO2RR activity 28887 28895 EN Yuki Sano Department of Chemistry, Graduate School of Science, Tohoku University Daichi Nakajima Department of Chemistry, Graduate School of Science, Tohoku University Biplab Manna Center for Basic Research on Materials, National Institute for Materials Science Koki Chida Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Ryojun Toyoda Department of Chemistry, Graduate School of Science, Tohoku University Shinya Takaishi Department of Chemistry, Graduate School of Science, Tohoku University Kazuyuki Iwase Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Koji Harano Center for Basic Research on Materials, National Institute for Materials Science Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Takeharu Yoshii Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Ryota Sakamoto Department of Chemistry, Graduate School of Science, Tohoku University Metal–nitrogen-doped carbon materials (MNCs) exhibit good electrocatalytic performance owing to the intrinsic advantages of carbon-based materials and the presence of isolated and stabilized metal atoms coordinated by nitrogen sites. However, conventional high-temperature pyrolysis of precursor molecules make it difficult to control the coordination structure precisely. To address this issue, here we report a new synthesis strategy for MNCs. Specifically, we design and synthesize Ni-phthalocyanine functionalized with ethynyl groups as solid-state thermal polymerization points. After depositing the Ni-phthalocyanine precursor on a carbon support and performing a thermal treatment, the resultant carbon composite material features a Ni–N4 coordination structure derived from the precursor, and enhanced porosity. This material demonstrates high catalytic activity for the CO2 reduction reaction (CO2RR). Our synthetic approach is applicable to various precursor molecules and carbon supports, paving the way for the further development of MNC-based electrode catalysts. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0008-6223 243 2025 Organic solvent transport through reduced graphene oxide membranes with controlled oxygen content 120539 EN Hongzhe Chen School of Materials Science and Engineering, University of New South Wales Sydney Tongxi Lin School of Materials Science and Engineering, University of New South Wales Sydney Zeno Rizqi Ramadhan Electron Microscope Unit, University of New South Wales Aditya Rawal Mark Wainwright Analytical Centre, University of New South Wales Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Amir Karton School of Science and Technology, University of New England Xiaojun Ren School of Materials Science and Engineering, University of New South Wales Sydney Rakesh Joshi School of Materials Science and Engineering, University of New South Wales Sydney Recent advances in membranes based on 2-dimensional (2D) materials have enabled precise control over angstrom-scale pores, providing a unique platform for studying diverse mass transport mechanisms. In this work, we systematically investigate the transport of solvent vapors through 2D channels made of graphene oxide (GO) laminates with precisely controlled oxygen content. Using in-situ chemical reduction of GO with vitamin C, we fabricated reduced GO membranes (VRGMs) with oxygen content systematically decreased from 31.6 % (pristine GO) to 24.0 % (VRGM-maximum reduction). Vapor permeability measurements showed a distinct correlation between oxygen functional groups and solvent transport behaviour. Specifically, non-polar hexane exhibits 114 % of enhanced permeance through the reduced membranes with larger graphitic domains, while the permeance of water decreases by 55 %. With the support of density functional theory (DFT) simulations, we modelled the hydrogen-bond and dispersion complexes between the solvents and GO and calculated the complexation energies. The simulation results suggest that polar molecules interact with the oxygen functional groups of GO via a hydrogen-bond network, supporting in-plane transport. In contrast, van der Waals forces drive the transport of low-polarity solvents along the graphitic domains of the 2D channel in reduced GO membranes. Our findings provide potential strategies for future design of organic solvent nanofiltration membranes. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 2053-1583 12 4 2025 Covalent cross-linked graphene oxide aerogels for moisture adsorption 045010 EN Zhijian Cao School of Materials Science and Engineering, University of New South Wales Xiaojun Ren School of Materials Science and Engineering, University of New South Wales Tongxi Lin School of Materials Science and Engineering, University of New South Wales Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Masamichi Yoshimura Graduate School of Engineering, Toyota Technological Institute Rakesh Joshi School of Materials Science and Engineering, University of New South Wales Covalent cross-linking is an effective approach to enhance the hydrophilicity and water adsorption properties of graphene oxide (GO). We studied moisture absorption in GO cross-linked with poly(ethylene glycol) diamines. At relative humidity (RH) of 85%, the PEG-cross-linked GO exhibited a significantly enhanced water uptake capacity of 0.59 g of water per gram of GO (gg−1), compared to 0.37 for unmodified GO. This is attributed to the presence of alkoxy groups via cross-linking, resulting in the enhanced interaction between GO and water molecules. These findings highlight the potential of PEG-based covalent functionalisation for efficient moisture capture in GO-based materials. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2694-2496 2025 RNA Delivery Using a Graphene Oxide-Polyethylenimine Hybrid Inhibiting Myotube Differentiation EN Koji Matsuura CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Giacomo Reina CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Zhengfeng Gao CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Alberto Bianco CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Graphene oxide (GO) conjugated with short polyethylenimine (PEI) chains (GO-PEI) has been designed as a candidate nanocarrier for small interfering RNA (siRNA) delivery to mammalian cells based on the efficient interaction between the positively charged GO-based platform and the negatively charged siRNA. The function and efficiency of siRNA delivery using GO-PEI were compared to those using the positive control Lipofectamine RNAiMax by analyzing the differentiation to myotubes, and myogenin gene and protein expression in C2C12 cells. RNAiMax transfection induced cellularization and reduction of both myogenin gene and protein expression, suggesting that the differentiation of C2C12 cells was triggered by gene silencing. While GO-PEI also promoted cellularization, the myogenin gene expression remained comparable to scrambled controls, whereas the protein levels were higher than those observed with RNAiMax. Mechanistically, we attributed the reduced gene silencing efficiency of GO-PEI to a poor endosomal escape, despite strong siRNA complexation. This limitation was likely due to a low buffering capacity of GO-PEI, as a significant fraction of nitrogen atoms were already protonated, reducing the availability of free amines necessary for endosomal disruption. An appropriate chemical modification to enhance siRNA release from the endosomes is therefore essential for advancing the development of GO-based platforms as versatile and efficient nanocarriers in gene therapy applications. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2640-4567 2025 Integration of Cholesterol Oxidase‐Based Biosensors on a Smart Contact Lens for Wireless Cholesterol Monitoring from Tears 2500368 EN Yang Cui Graduate school of Information, Production and Systems, Waseda University Lin Zhuo Graduate school of Information, Production and Systems, Waseda University Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Saman Azhari Graduate school of Information, Production and Systems, Waseda University Takeo Miyake Graduate school of Information, Production and Systems, Waseda University Cholesterol plays a critical role in physiological functions, but elevated levels increase the risk of cardiovascular disease. Regular cholesterol monitoring is essential for elderly or obese individuals. Current methods, such as blood tests, are invasive, inconvenient, and require a professional operator. In contrast, tears, as an accessible body fluid, offer a promising alternative for noninvasive monitoring due to their correlation with blood cholesterol levels. Herein, a noninvasive approach for monitoring cholesterol levels in tears using a biosensor integrated into a smart contact lens is reported. The biosensor employs cholesterol oxidases as the biocatalyst, coupled with an osmium-based mediator, to detect cholesterol concentrations ranging from 0.1 mM to 1.2 mM in artificial tears. A key challenge is the extremely low cholesterol concentration in tears, which is addressed using a parity-time (P-T) symmetry-based magnetic resonance coupling system. This system enables wireless signal reading and achieves high sensitivity due to its high-quality (Q) factor, which can achieve a detection limit of 0.061 mM. This portable, high-sensitivity smart contact lens demonstrates significant potential as a wearable device for continuous, noninvasive cholesterol monitoring. The findings contribute to advancing tear-based diagnostic systems and highlight the scientific importance of utilizing tear biomarkers for health monitoring. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 1743-6095 2025 Dual-action intranasal oxytocin enhances both male sexual performance and fertility in rats 1 3 EN Chica Enomoto Department of Biology, Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takumi Oti Department of Biology, Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takahiro Yamanaka Laboratory of Reproductive Endocrinology, Graduate School of Integrated Sciences for Life, Hiroshima University Masayuki Shimada Laboratory of Reproductive Endocrinology, Graduate School of Integrated Sciences for Life, Hiroshima University Hirotaka Sakamoto Department of Biology, Faculty of Environmental, Life, Natural Science and Technology, Okayama University No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 2025 Generation of alkyl radicals via C(sp3)–C(sp3) bond cleavage of xanthene-based precursors for photocatalytic Giese-type reaction EN Shuta Horiuchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Masato Oishi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Asuka Mizutani Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University Novel xanthene-based alkyl radical precursors were developed and subjected to photocatalytic C(sp3)–C(sp3) bond cleavage for the efficient generation of alkyl radicals, which were subsequently reacted with various alkenes to afford the corresponding Giese-type products. After the reaction, the produced xanthones can be recovered in high yield. No potential conflict of interest relevant to this article was reported.

Institute of Electrical and Electronics Engineers (IEEE) Acta Medica Okayama 2169-3536 13 2025 Optimized Ensemble Deep Learning for Real-Time Intrusion Detection on Resource-Constrained Raspberry Pi Devices 113544 113556 EN Muhammad Bisri Musthafa Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Samsul Huda Interdisciplinary Education and Research Field, Okayama University Tuy Tan Nguyen School of Informatics, Computing, and Cyber Systems, Northern Arizona University Yuta Kodera Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yasuyuki Nogami Graduate School of Environmental, Life, Natural Science and Technology, Okayama University The rapid growth of Internet of Things (IoT) networks has increased security risks, making it essential to have effective Intrusion Detection Systems (IDS) for real-time threat detection. Deep learning techniques offer promising solutions for such detection due to their superior complex pattern recognition and anomaly detection capabilities in large datasets. This paper proposes an optimized ensemble-based IDS designed specifically for efficient deployment on edge hardware. However, deploying such computationally intensive models on resource-limited edge devices remains a significant challenge due to model size and computational overhead on devices with limited processing capabilities. Building upon our previously developed stacked Long Short-Term Memory (LSTM) model integrated with ANOVA feature selection, we optimize it by integrating dual-stage model compression: pruning and quantization to create a lightweight model suitable for real-time inference on Raspberry Pi devices. To evaluate the system under realistic conditions, we combined with a Kafka-based testbed to simulate dynamic IoT environments with variable traffic loads, delays, and multiple simultaneous attack sources. This enables the assessment of detection performance under varying traffic volumes, latency, and overlapping attack scenarios. The proposed system maintains high detection performance with accuracy of 97.3% across all test scenarios, while efficiently leveraging multi-core processing with peak CPU usage reaching 111.8%. These results demonstrate the system’s practical viability for real-time IoT security at the edge. No potential conflict of interest relevant to this article was reported.

Institute of Electrical and Electronics Engineers (IEEE) Acta Medica Okayama 2169-3536 13 2025 Security in Post-Quantum Era: A Comprehensive Survey on Lattice-Based Algorithms 89003 89024 EN Hien Nguyen School of Informatics, Computing, and Cyber Systems, Northern Arizona University Samsul Huda Interdisciplinary Education and Research Field, Okayama University Yasuyuki Nogami Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tuy Tan Nguyen School of Informatics, Computing, and Cyber Systems, Northern Arizona University Lattice-based post-quantum cryptography (PQC) has attracted significant attention as a promising solution to the security challenges posed by quantum computing. Unlike traditional cryptographic algorithms, lattice-based schemes are expected to remain secure even in the presence of quantum attacks, making them essential for securing future data. Despite their strong theoretical foundations, lattice-based schemes face several practical challenges, particularly in optimizing performance and scalability for real-world applications. This survey provides a novel taxonomy that categorizes lattice-based PQC designs, with an emphasis on computational paradigms and security considerations. We systematically evaluate lattice-based PQC implementations across both software platforms, including central processing units and graphics processing units, as well as hardware platforms like field-programmable gate arrays and application-specific integrated circuits, highlighting their strengths and limitations. In addition, we explore the practical applications of lattice-based cryptography in fields such as secure communication, critical infrastructure, privacy-preserving data analytics, artificial intelligence, and trust and authentication systems. By offering a comprehensive overview of the current state of lattice-based PQC, this survey aims to provide valuable insights into the ongoing advancements and future research directions in the field as we transition to a post-quantum era. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1939-5981 2025 MATERIAL PROPERTIES OF DIE-CASTING DIE AROUND HEAT-CHECKING CREATED BY A HIGH-PRESSURE ALUMINUM ALLOY DIE-CASTING OPERATION EN Mitsuhiro Okayasu Department of Mechanical Systems Engineering, Okayama University Junya Shimazu Department of Mechanical Systems Engineering, Okayama University In this study, the material properties of a nitride die-casting die exhibiting heat-checking after the die-casting process were experimentally investigated using various methods. Based on the obtained results, the authors believe that several possible mechanisms underlying the formation of heat-checking can be identified. The microstructure of the die-casting die near the heat-checking region is characterized by equiaxed grains along the vicinity of the prior γ-grain boundaries, resulting from the lath martensitic formation. Additionally, numerous Cr–Mo–V-based nitride particles, approximately 100 nm in diameter, are precipitated. The surface hardness of the die-casting die, enhanced by nitriding, induces compressive residual stresses and increases adhesive forces. As a result of changes in microstructural characteristics and crack formation, the stress state near the die-casting die is altered, where compressive residual stresses, observed in the die-casting die, are released, leading to the tensile residual stresses. This phenomenon could accelerate the formation of a large number of heat-checking cracks. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2227-7080 13 4 2025 An Implementation of Creep Test Assisting System with Dial Gauge Needle Reading and Smart Lighting Function for Laboratory Automation 139 EN Dezheng Kong Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nobuo Funabiki Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Shihao Fang Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Noprianto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Mitsuhiro Okayasu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Pradini Puspitaningayu Department of Electrical Engineering, Universitas Negeri Surabaya For decades, analog dial gauges have been essential for measuring and monitoring data at various industrial instruments including production machines and laboratory equipment. Among them, we focus on the instrument for creep test in a mechanical engineering laboratory, which evaluates material strength under sustained stress. Manual reading of gauges imposes significant labor demands, especially in long-duration tests. This burden further increases under low-lighting environments, where poor visibility can lead to misreading data points, potentially compromising the accuracy of test results. In this paper, to address the challenges, we implement a creep test assisting system that possesses the following features: (1) to save the installation cost, a web camera and Raspberry Pi are employed to capture images of the dial gauge and automate the needle reading by image processing in real time, (2) to ensure reliability under low-lighting environments, a smart lighting mechanism is integrated to turn on a supplementary light when the dial gauge is not clearly visible, and (3) to allow a user to stay in a distant place from the instrument during a creep test, material break is detected and the corresponding message is notified to a laboratory staff using LINE automatically. For evaluations, we install the implemented system into a material strength measuring instrument at Okayama University, Japan, and confirm the effectiveness and accuracy through conducting experiments under various lighting conditions. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 0024-9297 58 3 2025 Synthesis and Postfunctionalization of Acrylate-Appended Poly(cyclohexene carbonate)s: Modulation of Properties of CO2-Based Polymers 1571 1577 EN Chihiro Maeda Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Hina Inoue Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Tadashi Ema Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Functional CO2-based polycarbonates are expected to be sustainable materials. Herein, a bifunctional aluminum porphyrin catalyzed the terpolymerization of cyclohexene oxide (CHO), acrylate-appended CHO, and CO2 to provide poly(cyclohexene carbonate)s (PCHCs) with acrylate groups. Postfunctionalization of PCHCs via Michael addition or Heck reaction enabled the incorporation of thiol, amine, and aromatics into PCHCs with high selectivity and efficiency. PCHCs with the flexible long alkyl chains showed a glass-transition temperature (Tg) of down to 52 °C, which was much lower than that of PCHC (127 °C). In sharp contrast, PCHCs with rigid pyrenyl groups showed Tg values of up to 152 °C and fluorescence emission. Thus, a wide range of polymers were obtained by robust and sustainable synthetic methods, and the functional groups modulated the properties of the CO2-based polycarbonates. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0947-8396 131 9 2025 Optical and chemical properties of silver tree-like structure treated with gold galvanic substitution 744 EN Kazushi Honda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nobuyuki Takeyasu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Galvanic gold substitution was executed in the presence of trisodium citrate on silver tree-like structures. No discernible difference in geometry was observed between the pre- and post-gold substitution phases, which benefited from the presence of citrate ions. The extent of gold substitution was regulated by the amount of gold ion solution added. After the gold substitution, an increase in extinction was observed in the ultraviolet region, indicating that gold was deposited at the surface. Raman scattering of para-toluenethiol was measured on the gold/silver tree-like structures at 488 nm excitations, where a decrease in the Raman peak intensity was observed as the quantity of gold ion solution increased. The results indicated that the optical property of silver was lost due to the increase of the amount of gold deposition. Concurrently, an investigation was conducted into the chemical resistance of the gold/silver tree-like structures, which was evaluated by measuring the resistivity inverse-proportional to the amount of silver ions dissolved by the diluted nitric acid. As the amount of gold ion solution added increased, the resistivity increased and became constant. The result implied that the surface chemical property had undergone a complete transformation into gold. No potential conflict of interest relevant to this article was reported.

International Union of Crystallography (IUCr) Acta Medica Okayama 2052-2525 12 5 2025 Illuminating DNA repair in action: structural insights into a photocaged glycosylase complex 513 514 EN Michihiro Suga Research Institute for Interdisciplinary Science, Okayama University No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0956-5663 287 2025 A plant-insertable multi-enzyme biosensor for the real-time monitoring of stomatal sucrose uptake 117674 EN Shiqi Wu Graduate School of Information, Production and Systems, Waseda University Wakutaka Nakagawa Graduate School of Information, Production and Systems, Waseda University Yuki Mori Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu Saman Azhari Graduate School of Information, Production and Systems, Waseda University Gábor Méhes Graduate School of Information, Production and Systems, Waseda University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Tomonori Kawano Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu Takeo Miyake Graduate School of Information, Production and Systems, Waseda University Monitoring sucrose transport in plants is essential for understanding plant physiology and improving agricultural practices, yet effective sensors for continuous and real-time in-vivo monitoring are lacking. In this study, we developed a plant-insertable sucrose sensor capable of real-time sucrose concentration monitoring and demonstrated its application as a useful tool for plant research by monitoring the sugar-translocating path from leaves to the lower portion of plants through the stem in living plants. The biosensor consists of a bilirubin oxidase-based biocathode and a needle-type bioanode integrating glucose oxidase, invertase, and mutarotase, with the two electrodes separated by an agarose gel for ionic connection. The sensor exhibits a sensitivity of 6.22 μA mM−1 cm−2, a limit of detection of 100 μM, a detection range up to 60 mM, and a response time of 90 s at 100 μM sucrose. Additionally, the sensor retained 86 % of its initial signal after 72 h of continuous measurement. Day-night monitoring from the biosensor inserted in strawberry guava (Psidium cattleianum) showed higher sucrose transport activity at night, following well the redistribution of photosynthetically produced sugars. In addition, by monitoring the forced translocation of sucrose dissolved in the stable isotopically labeled water, we demonstrated that a young seedling of Japanese cedar known as Sugi (Cryptomeria japonica) can absorb and transport both water and sucrose through light-dependently opened stomata, which is the recently revealed path for liquid uptake by higher plants. These findings highlight the potential of our sensor for studying dynamic plant processes and its applicability in real-time monitoring of sugar transport under diverse environmental conditions. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 1742-6588 2892 2024 Crystal Grain Rotation during Tensile Test of Polycrystalline Pure Titanium Thin Sheet Based on Surface Height and Crystal Orientation 012002 EN Naoya Tada Okayama University Hiroaki Ohashi Okayama University Takeshi Uemori Okayama University Junji Sakamoto Okayama University Thin sheets and wires of polycrystalline pure titanium are important materials for various devices used in electrical, mechanical, dental, and medical fields. Since pure titanium shows strong anisotropy in elastic and plastic deformation, and the individual grains comprising a polycrystalline body have different orientations and geometries, inhomogeneous deformation always occurs on the microscopic scale. This inhomogeneity is more significant in thin films than in bulk materials. It is therefore important to investigate the inhomogeneous deformation of pure titanium thin sheets to ensure the reliability of various titanium devices. In this study, thin-sheet specimens made of polycrystalline pure titanium were subjected to tensile testing. Inhomogeneous deformation was evaluated on the basis of two kinds of crystal grain rotations based on surface height and crystal orientation. The results under elastic and plastic tensile conditions were compared. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 0009-2673 98 6 2025 Redox-potential-controlled intermolecular [2 + 2] cycloaddition of styrenes for the regio- and diastereoselective synthesis of multisubstituted halogenocyclobutanes uoaf044 EN Asuka Mizutani Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Momo Kondo Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science Shoko Itakura Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yujiro Hoshino Graduate School of Environment and Information Sciences, Yokohama National University Makiya Nishikawa Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kosuke Kusamori Laboratory of Cellular Drug Discovery and Development, Faculty of Pharmaceutical Sciences, Tokyo University of Science Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University The redox potential is an important factor for controlling the outcome of photoredox catalysis. Particularly, the selective oxidation of substrates and the control over the reactions are challenging when using photoredox catalysts that have high excited-state reduction potentials. In this study, a redox-potential-controlled intermolecular [2 + 2] cycloaddition of styrenes using a thioxanthylium organophotoredox (TXT) catalyst has been developed. This TXT catalyst selectively oxidizes β-halogenostyrenes and smoothly promotes the subsequent intermolecular [2 + 2] cycloadditions to give multisubstituted halogenocyclobutanes with excellent regio- and diastereoselectivity, which has not been effectively achieved by the hitherto reported representative photoredox catalysts. The synthesized halogenocyclobutanes exhibit interesting free radical scavenging activity. The present reaction contributes to the field of redox-potential-controlled electron transfer chemistry. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0009-4536 2025 Elucidation of the relationship between solid‐state photoluminescence and crystal structures in 2,6‐substituted naphthalene derivatives EN Minoru Yamaji Department of Applied Chemistry, Division of Materials and Environment, Graduate School of Science and Engineering, Gunma University Isao Yoshikawa Department of Materials and Environmental Science, Institute of Industrial Science, The University of Tokyo Toshiki Mutai Technology Transfer Service Corporation Hirohiko Houjou Department of Materials and Environmental Science, Institute of Industrial Science, The University of Tokyo Kenta Goto Institute for Materials Chemistry and Engineering, Kyushu University Fumito Tani Institute for Materials Chemistry and Engineering, Kyushu University Kengo Suzuki Hamamatsu Photonics K.K Hideki Okamoto Department of Chemistry, Faculty of Environment, Life, Natural Sciences and Technology, Okayama University Polycyclic aromatic hydrocarbons (PAHs) are known to exhibit fluorescence in solution, but generally do not emit in the solid state, with the notable exception of anthracene. We previously reported that PAHs containing multiple chromophores show solid-state emission, and we have investigated the relationship between their crystal structures and photoluminescence properties. In particular, PAHs with herringbone-type crystal packing, such as 2,6-diphenylnaphthalene (DPhNp), which has a slender and elongated molecular structure, exhibits red-shifted solid-state fluorescence spectra relative to their solution-phase counterparts. In this study, we synthesized 2,6-naphthalene derivatives bearing phenyl and/or pyridyl substituents (PhPyNp and DPyNp) and observed distinct, red-shifted emission in the solid state compared with that in solution. Crystallographic analysis revealed that both PhPyNp and DPyNp adopt herringbone packing motifs. These findings support our hypothesis that the spectral characteristics of PAH emission are closely linked to crystal packing arrangements, providing a useful strategy for screening PAH candidates for applications in organic semiconducting materials. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1613-6810 2025 Polyglycerol‐Grafted Graphene Oxide with pH‐Responsive Charge‐Convertible Surface to Dynamically Control the Nanobiointeractions for Enhanced in Vivo Tumor Internalization 2503029 EN Yajuan Zou Research Institute for Interdisciplinary Science, Okayama University Alberto Bianco Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University pH-responsive charge-convertible nanomaterials (NMs) ameliorate the treatment of cancer via simultaneously reducing nonspecific interactions during systemic circulation and improving targeted uptake within solid tumors. While promising, little is known about how the pH-responsiveness of charge-convertible NMs directs their interactions with biological systems, leading to compromised performance, including off-target retention and low specificity to tumor cells. In the present study, polyglycerol-grafted graphene oxide bearing amino groups (GOPGNH2) at different densities are reacted with dimethylmaleic anhydride (DMMA), a pH-responsive moiety, to generate a set of charge-convertible GOPGNH-DMMA variants. This permits the assessment of a quantitative correlation between the structure of GOPGNH-DMMA to their pH-responsiveness, their dynamic interactions with proteins and cells, as well as their in vivo biological fate. Through a systematic investigation, it is revealed that GOPGNH115-DMMA prepared from GOPGNH2 with higher amine density experienced fast charge conversion at pH 7.4 to induce non-specific interactions at early stages, whereas GOPGNH60-DMMA and GOPGNH30-DMMA prepared from lower amine density retarded off-target charge conversion to enhance tumor accumulation. Notably, GOPGNH60-DMMA is also associated with enough amounts of proteins under acidic conditions to promote in vivo tumor internalization. The findings will inform the design of pH-responsive NMs for enhanced treatment accuracy and efficacy. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2079-6447 3 4 2024 N-Phenylphenothiazine Radical Cation with Extended π-Systems: Enhanced Heat Resistance of Triarylamine Radical Cations as Near-Infrared Absorbing Dyes 350 359 EN Masafumi Yano Faculty of Chemistry, Material and Bioengineering, Kansai University Minami Ueda Faculty of Chemistry, Material and Bioengineering, Kansai University Tatsuo Yajima Faculty of Chemistry, Material and Bioengineering, Kansai University Koichi Mitsudo Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yukiyasu Kashiwagi Osaka Research Institute of Industrial Science and Technology N-Phenylphenothiazine derivatives extended with various aryl groups were designed and synthesized. These derivatives have bent conformation in crystal and exhibit high solubility. Radical cations obtained by one-electron oxidation of these derivatives gave stable radical cations in solution and showed absorption in the near-infrared region. A radical cation was isolated as a stable salt, which exhibited heat resistance up to around 200 °C. A design strategy for radical cation-based near-infrared absorbing dyes, which are easily oxidized and stable not only as a solution but in solid form, is described. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2691-3704 5 2 2025 Mechanistic Insights Into Oxidative Response of Heat Shock Factor 1 Condensates 606 617 EN Soichiro Kawagoe Institute of Advanced Medical Sciences, Tokushima University Motonori Matsusaki Institute of Advanced Medical Sciences, Tokushima University Takuya Mabuchi Frontier Research Institute for Interdisciplinary Sciences, Tohoku University Yuto Ogasawara Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kazunori Watanabe Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Koichiro Ishimori Department of Chemistry, Faculty of Science, Hokkaido University Tomohide Saio Institute of Advanced Medical Sciences, Tokushima University Heat shock factor 1 (Hsf1), a hub protein in the stress response and cell fate decisions, senses the strength, type, and duration of stress to balance cell survival and death through an unknown mechanism. Recently, changes in the physical property of Hsf1 condensates due to persistent stress have been suggested to trigger apoptosis, highlighting the importance of biological phase separation and transition in cell fate decisions. In this study, the mechanism underlying Hsf1 droplet formation and oxidative response was investigated through 3D refractive index imaging of the internal architecture, corroborated by molecular dynamics simulations and biophysical/biochemical experiments. We found that, in response to oxidative conditions, Hsf1 formed liquid condensates that suppressed its internal mobility. Furthermore, these conditions triggered the hyper-oligomerization of Hsf1, mediated by disulfide bonds and secondary structure stabilization, leading to the formation of dense core particles in the Hsf1 droplet. Collectively, these data demonstrate how the physical property of Hsf1 condensates undergoes an oxidative transition by sensing redox conditions to potentially drive cell fate decisions. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1598-2351 2025 Hydrogen Embrittlement Characteristics of Austenitic Stainless Steels After Punching Process EN Mitsuhiro Okayasu Department of Mechanical and Systems Engineering, Okayama University Xichang Li Department of Mechanical and Systems Engineering, Okayama University Tomohisa Kawakami SHOYO SANGYO Co., Ltd. This study investigates the influence of microstructural characteristics on the hydrogen embrittlement of SUS304 austenitic stainless steel. The investigation utilized SUS304 sheets with a thickness of 1.5 mm, which were processed by punching with an 8 mm diameter to make specimens. Severe plastic deformation was localized near the punching edge, with the extent of deformation determined by the punching speed. Slower punching speeds induced more pronounced plastic strain, which was closely associated with work hardening and strain-induced martensitic (SIM) transformation. The SIM phase was predominantly observed within a depth of approximately 0.1 mm from the punched edge when processed at a punching speed of 0.25 mm/s, corresponding to roughly 10% of the cross-sectional area of the sample. These microstructural changes led to a significant reduction in tensile and fatigue strength, thereby exacerbating susceptibility to severe hydrogen embrittlement, despite the limited extent of microstructural alteration. Based on these findings, a modified Goodman diagram for SUS304 austenitic stainless steel, incorporating mechanical properties and hydrogen embrittlement behavior, was proposed. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2452-3216 68 2025 Method for predicting crack size using amplitude change in titanium alloy under bending vibration 1319 1323 EN Junji Sakamoto Okayama University, Faculty of Environmental, Life, Natural Science and Technology Naoya Tada Okayama University, Faculty of Environmental, Life, Natural Science and Technology Takeshi Uemori Okayama University, Faculty of Environmental, Life, Natural Science and Technology The natural frequency of a material decreases owing to the presence of cracks. Thus, when a crack initiates in a material under vibration, the amplitude of the vibration changes with the crack propagation. In this study, we investigated a method for predicting crack size using the amplitude change in a plate specimen of a titanium alloy under bending vibration. The bending displacement amplitudes were measured using high-speed camera images of the specimens. The crack sizes were measured using optical microscopy images of plastic replicas of the specimen surfaces that were obtained after interrupting tests at specified intervals. By using the relationship between the total area of the cracks and bending displacement amplitude for tests at two different vibration frequencies as well as the relationship between the vibration frequency and bending displacement amplitude for an undamaged specimen, the bending displacement amplitude at any vibration frequency can be monitored to predict the total area of the cracks. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1939-5981 2025 Study of the Mechanical Properties of Al–Mg ADC6 Aluminum Alloy Produced by Unidirectional Casting Under Various Cooling Rates EN S. Takeuchi M. Okayasu To create the high strength and high ductility of Al–Mg-based aluminum alloy (JIS–ADC6), ADC6 samples were produced by the unidirectional continuous casting (HMC). The HMC process was conducted with direct water cooling to melt ADC6, which can make fine microstructures and control crystal orientation. The cast samples were prepared under various cooling rates (CRs): 6.3, 34, and 62 K/s. The microstructure and crystal orientation of the samples were altered with CR. At CRs of 34 K/s and 62 K/s, the α-Al phases and intermetallic compounds, e.g., Mg2Si and Al15(Fe, Mn)3Si2, became finer and more spherical. The secondary dendrite arm spacing for the sample at 62 K/s was 8.7 µm―more than 70% smaller than the ADC6 sample (ingot) made by a gravity casting process. Notably, at a CR of 34 K/s, the crystal orientation was predominantly arranged with the (101) plane. Tensile properties―ultimate tensile strength (σUTS), 0.2% proof stress (σ0.2), and failure strain (εf)―varied with the CR. The tensile strength (σUTS and σ0.2) consistently increased with increasing the CR. The improvement in the tensile strength resulted from the refined microstructures, such as the α-Al phase and intermetallic compounds. Similarly, the failure strain also increased with increasing CR, which was severely affected by the finer and more spherical intermetallic compounds. In this case, the εf value of the sample at 34 K/s was, however, slightly higher than that at 62 K/s, due to more uniformly organized crystal orientation, while their ductility was much higher than that of the gravity cast sample. The tensile properties in detail were further analyzed using their failure characteristics. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1613-6810 2025 Droplet Transportation on Janus Harp Wires for Enhanced Fog Harvesting e06765 EN Yutaka Yamada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Taku Ishikawa Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kazuma Isobe Faculty of Environmental, Life, Natural Science and Technology, Okayama University Akihiko Horibe Faculty of Environmental, Life, Natural Science and Technology, Okayama University Ensuring freshwater resources is a vital issue for human beings worldwide. Fog harvesting is one promising way to provide water from unconventional sources. However, clogging by the captured liquid depresses the fog harvesting performance. Here, a harp-shaped Janus harvesting system, which has thin wires with a superhydrophobic side facing the fog stream and a superhydrophilic back side to transport the droplets, is used to yield simultaneous fog capturing and water transport abilities. Attached droplets on the Janus wire transported along the periphery avoided clogging and enhanced the performance. The Janus system thus suppressed the increase and fluctuations of actual shade coefficients, which indicated blockage of the fog stream. This optimized the design of the harvester. Experiments using a multilayered Janus harvester demonstrated a significant enhancement compared with that constructed with mono-wettability wires. Overall, the results indicated the promise of droplet transportation on single wires for improving fog harvesting, as well as for other applications such as oil mist recovery and demulsification. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2637-6105 2025 Tailoring Mechanical Properties and Ionic Conductivity of Poly(ionic liquid)-Based Ion Gels by Tuning Anion Compositions EN Takaichi Watanabe Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Yuna Mizutani Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Carlos G. Lopez Material Science and Engineering Department, The Pennsylvania State University, 80 Pollock Road, State College Tsutomu Ono Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Poly(ionic liquid) (PIL)-based ion gels have emerged as promising materials for advanced electrochemical applications because of their excellent miscibility with ionic liquids (IL), tunable mechanical properties, and high ionic conductivity. Despite extensive studies on PIL-based ion gels, a comprehensive understanding of how different anion combinations in the system affect physicochemical properties is lacking. In this study, we systematically investigate the effect of different anion species, such as bis(trifluoromethanesulfonyl)imide (TFSI) and hexafluorophosphate (PF6), on the mechanical, viscoelastic, and ion conductive behaviors of PIL-based ion gels. We investigate the interplay between anion size, packing density, and polymer segmental dynamics by varying the anion composition in both the PIL network and IL component. Rheological analysis and uniaxial tensile testing results indicate that PF6-containing ion gels exhibit enhanced higher Young’s modulus because of their restricted chain mobility resulting in higher glass transition temperature (Tg). In addition, we confirm the anion exchange between PIL and IL during gel preparation and find that the mechanical and ion conductive properties of the gels are governed by the total molar ratio of anions in the gels. Our findings highlight that tuning the anion composition in PIL-based ion gels provides an effective strategy to tailor their performance, with potential applications for flexible electronics and solid-state electrochemical devices. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2642-4150 2025 Electrostatically‐Driven Collapse of Polyelectrolytes: The Role of the Solvent's Dielectric Constant EN Anish Gulati Institute of Physical Chemistry, RWTH Aachen University Lingzi Meng Materials Science and Engineering Department, The Pennsylvania State University, State College Takaichi Watanabe Department of Applied Chemistry, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Carlos G. Lopez Materials Science and Engineering Department, The Pennsylvania State University, State College We experimentally confirm a longstanding theoretical prediction of counterion-induced polyelectrolyte collapse in low dielectric media. The scattering behavior of polystyrene sulfonate in different solvents with dielectric permittivities in the range of ε ≃ 12 − 180 is investigated. For high and intermediate ε media, typical polyelectrolyte behavior is observed: the correlation length (ξ) scales with concentration (c) as ξ ∼ c−1∕2, as predicted by various theories. When the dielectric constant of the solvent decreases below ≃ 22, a scaling of ξ ∼ c−1∕3, characteristic of partially collapsed polyelectrolytes, is observed. For these solvents, the correlation peak disappears at high concentrations. Interestingly, polyelectrolyte collapse is observed under both solvophilic and solvophobic conditions, supporting the existence of attractive electrostatic interactions. These results are in qualitative agreement with theoretical predictions which expect chain collapse in low dielectric media due to the influence of condensed counterions, either via dipolar attraction and/or charge-correlation-induced attractions. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2192-2640 14 10 2024 Biocompatibility of Water-Dispersible Pristine Graphene and Graphene Oxide Using a Close-to-Human Animal Model: A Pilot Study on Swine 2401783 EN Paola Nicolussi Istituto Zooprofilattico Sperimentale della Sardegna Giovannantonio Pilo Istituto Zooprofilattico Sperimentale della Sardegna Maria Giovanna Cancedda Istituto Zooprofilattico Sperimentale della Sardegna Guotao Peng Institute of Environmental Medicine, Karolinska Institutet Ngoc Do Quyen Chau CNRS, Immunology, Immunopathology and Therapeutic Chemistry Alejandro De la Cadena Dipartimento di Fisica, Politecnico di Milano Renzo Vanna Istituto di Fotonica e Nanotecnologie – CNR Yarjan Abdul Samad Cambridge Graphene Centre, University of Cambridge Tanweer Ahmed Cambridge Graphene Centre, University of Cambridge Jeremia Marcellino Cambridge Graphene Centre, University of Cambridge Giuseppe Tedde Istituto Zooprofilattico Sperimentale della Sardegna Linda Giro ImmuneNano Laboratory, Department of Biomedical Sciences Acelya Ylmazer Department of Biomedical Engineering, Ankara University Federica Loi Istituto Zooprofilattico Sperimentale della Sardegna Gavina Carta Istituto Zooprofilattico Sperimentale della Sardegna Loredana Secchi Istituto Zooprofilattico Sperimentale della Sardegna Silvia Dei Giudici Istituto Zooprofilattico Sperimentale della Sardegna Simona Macciocu Istituto Zooprofilattico Sperimentale della Sardegna Dario Polli Dipartimento di Fisica, Politecnico di Milano Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Ciriaco Ligios Istituto Zooprofilattico Sperimentale della Sardegna Giulio Cerullo Dipartimento di Fisica, Politecnico di Milano Andrea Ferrari Cambridge Graphene Centre, University of Cambridge Alberto Bianco CNRS, Immunology, Immunopathology and Therapeutic Chemistry Bengt Fadeel Institute of Environmental Medicine, Karolinska Institutet Giulia Franzoni Istituto Zooprofilattico Sperimentale della Sardegna Lucia Gemma Delogu ImmuneNano Laboratory, Department of Biomedical Sciences Graphene-based materials (GBMs) are of considerable interest for biomedical applications, and the pilot study on the toxicological and immunological impact of pristine graphene (GR) and graphene oxide (GO) using swine as a close-to-human provides valuable insights. First, ex vivo experiments are conducted on swine blood cells, then GBMs are injected intraperitoneally (i.p.) into swine. Hematological and biochemical analyses at various intervals indicate that neither GO nor GR cause systemic inflammation, pro-coagulant responses, or renal or hepatic dysfunction. Importantly, no systemic toxicity is observed. Analysis of a panel of 84 immune-related genes shows minimal impact of GO and GR. The animals are sacrificed 21 days post-injection, and transient absorption imaging and Raman mapping show the presence of GO and GR in the mesentery only. Histological evaluation reveals no signs of alterations in other organs. Thus, clusters of both materials are detected in the mesentery, and GO aggregates are surrounded only by macrophages with the formation of granulomas. In contrast, modest local reactions are observed around the GR clusters. Overall, these results reveal that i.p. injection of GBMs resulted in a modest local tissue reaction without systemic toxicity. This study, performed in swine, provides essential guidance for future biomedical applications of graphene. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2694-2496 4 4 2024 Light-Responsive and Antibacterial Graphenic Materials as a Holistic Approach to Tissue Engineering 263 272 EN Andrea Ferreras Department of Bioengineering, Universidad Carlos III de Madrid Ana Matesanz Department of Electronic Technology, Universidad Carlos III de Madrid Jabier Mendizabal Domotek ingeniería prototipado y formación S.L. Koldo Artola Domotek ingeniería prototipado y formación S.L. Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Pablo Acedo Department of Electronic Technology, Universidad Carlos III de Madrid José L. Jorcano Department of Bioengineering, Universidad Carlos III de Madrid Amalia Ruiz Institute of Cancer Therapeutics, School of Pharmacy and Medical Sciences, Faculty of Life Sciences, University of Bradford Giacomo Reina Empa Swiss Federal Laboratories for Materials Science and Technology Cristina Martín Department of Bioengineering, Universidad Carlos III de Madrid While the continuous development of advanced bioprinting technologies is under fervent study, enhancing the regenerative potential of hydrogel-based constructs using external stimuli for wound dressing has yet to be tackled. Fibroblasts play a significant role in wound healing and tissue implants at different stages, including extracellular matrix production, collagen synthesis, and wound and tissue remodeling. This study explores the synergistic interplay between photothermal activity and nanomaterial-mediated cell proliferation. The use of different graphene-based materials (GBM) in the development of photoactive bioinks is investigated. In particular, we report the creation of a skin-inspired dressing for wound healing and regenerative medicine. Three distinct GBM, namely, graphene oxide (GO), reduced graphene oxide (rGO), and graphene platelets (GP), were rigorously characterized, and their photothermal capabilities were elucidated. Our investigations revealed that rGO exhibited the highest photothermal efficiency and antibacterial properties when irradiated, even at a concentration as low as 0.05 mg/mL, without compromising human fibroblast viability. Alginate-based bioinks alongside human fibroblasts were employed for the bioprinting with rGO. The scaffold did not affect the survival of fibroblasts for 3 days after bioprinting, as cell viability was not affected. Remarkably, the inclusion of rGO did not compromise the printability of the hydrogel, ensuring the successful fabrication of complex constructs. Furthermore, the presence of rGO in the final scaffold continued to provide the benefits of photothermal antimicrobial therapy without detrimentally affecting fibroblast growth. This outcome underscores the potential of rGO-enhanced hydrogels in tissue engineering and regenerative medicine applications. Our findings hold promise for developing game-changer strategies in 4D bioprinting to create smart and functional tissue constructs with high fibroblast proliferation and promising therapeutic capabilities in drug delivery and bactericidal skin-inspired dressings. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2691-3704 2025 Electrochemical Generation of Sulfonamidyl Radicals via Anodic Oxidation of Hydrogen Bonding Complexes: Applications to Electrosynthesis of Benzosultams EN Yasuyuki Okumura Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Koichi Mitsudo Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Amidyl radicals and sulfonamidyl radicals are widely used in the field of organic synthesis. In particular, the electrochemical oxidation of amides in the presence of bases is one of the most practical methods for generating amidyl radicals. However, it is often difficult to observe the “true” radical precursor, such as an amide anion and/or a hydrogen bonding complex with an amide and a base. We found that a sulfonamide and Bu4NOAc form a 1:1 hydrogen bonding complex by spectroscopic experiments. Cyclic voltammetry suggested that 1:1 hydrogen bonding complexes should be oxidized predominantly under the optimized conditions to afford a sulfonamidyl radical via the proton-coupled electron transfer (PCET) process by the oxidation of the complex. Thus-generated sulfonamidyl radicals could be used in the electrochemical synthesis of a variety of benzosultams. No potential conflict of interest relevant to this article was reported.

Japan Society on Water Environment Acta Medica Okayama 1348-2165 22 6 2024 Effects of Sediment Microbial Fuel Cells on CH4 and CO2 Emissions from Straw Amended Paddy Soil 271 285 EN Adhena Tesfau Bekele Graduate School of Environmental and Life Science, Okayama University Morihiro Maeda Graduate School of Environmental and Life Science, Okayama University Satoshi Akao Faculty of Science and Engineering, Doshisha University Hiroaki Somura Graduate School of Environmental and Life Science, Okayama University Chiyu Nakano Organization for Research Strategy and Development, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Straw returning into paddy soil enhances soil organic matter which usually promotes the emission of greenhouse gases to the atmosphere. The application of sediment microbial fuel cells (SMFCs) to paddy soil activates power-generating microorganisms and enhances organic matter biodegradation. In the present study, rice straw addition in SMFCs was examined to determine its effect on CH4 and CO2 emissions. Columns (height, 25 cm; inner diameter, 9 cm) with four treatments: soil without and with rice straw under SMFC and without SMFC conditions were incubated at 25°C for 70 days. Anodic potential values at 7 cm depth sediment were kept higher by SMFCs than those without SMFCs. Cumulative CH4 emission was significantly reduced by SMFC with straw amendment (p < 0.05) with no significant effect on CO2 emission. 16S rRNA gene analysis results showed that Firmicutes at the phylum, Closteridiales and Acidobacteriales at order level were dominant on the anode of straw-added SMFC, whereas Methanomicrobiales were in the treatment without SMFC, indicating that a certain group of methanogens were suppressed by SMFC. Our results suggest that the anodic redox environment together with the enrichment of straw-degrading bacteria contributed to a competitive advantage of electrogenesis over methanogenesis in straw-added SMFC system. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2470-1343 9 34 2024 Engineering Zeolitic-Imidazolate-Framework-Derived Mo-Doped Cobalt Phosphide for Efficient OER Catalysts 36114 36121 EN Mohammad Atiqur Rahman Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Ze Cai Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Zannatul Mumtarin Moushumy Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University Ryuta Tagawa Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Yoshiharu Hidaka Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Chiyu Nakano Research Core for Interdisciplinary Sciences, Okayama University Md. Saidul Islam Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Yoshihiro Sekine Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Shintaro Ida Institute of Industrial Nanomaterials (IINa), Kumamoto University Shinya Hayami Institute of Industrial Nanomaterials (IINa), Kumamoto University Designing a cheap, competent, and durable catalyst for the oxygen evolution reaction (OER) is exceedingly necessary for generating oxygen through a water-splitting reaction. In this project, we have designed a ZIF-67-originated molybdenum-doped cobalt phosphide (CoP) using a simplistic dissolution–regrowth method using Na2MoO4 and a subsequent phosphidation process. This leads to the formation of an exceptional hollow nanocage morphology that is useful for enhanced catalytic activity. Metal–organic frameworks, especially ZIF-67, can be used both as a template and as a metal (cobalt) precursor. Molybdenum-doped CoP was fabricated through a two-step synthesis process, and the fabricated Mo-doped CoP showed excellent catalytic activity during the OER with a lower value of overpotential. Furthermore, the effect of the Mo amount on the catalytic activity has been explored. The best catalyst (CoMoP-2) showed an onset potential of around 1.49 V at 10 mA cm–2 to give rise to a Tafel slope of 62.1 mV dec–1. The improved catalytic activity can be attributed to the increased porosity and surface area of the resultant catalyst. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0008-6223 238 2025 Grafting-through functionalization of graphene oxide with cationic polymers for enhanced adsorption of anionic dyes and viruses 120296 EN Ryota Kimura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Pilar Ferré-Pujol Research Core for Interdisciplinary Sciences, Okayama University Yuta Nishina Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Graphene oxide (GO) is a sheet-like carbon material with abundant oxygen-containing functional groups on its surface. GO has been extensively studied as an adsorbent for heavy metals and organic compounds. However, effective strategies for negatively charged materials have yet to be established. This study aimed to synthesize composites of GO and cationic polymers for the selective adsorption of negatively charged materials; a challenge in this approach is the strong electrostatic interactions between GO and cationic polymers, which can lead to aggregation. This study addresses this issue by employing the grafting-through method. GO was initially modified with allylamine to introduce a polymerizable site, followed by radical polymerization to covalently bond polymers to the GO surface, effectively preventing aggregation. Adsorption experiments demonstrated that the GO-polymer composite selectively adsorbs anionic dye, such as methyl orange. Virus adsorption tests showed significantly enhanced performance compared to pristine GO. These results emphasize the critical role of controlled surface modification and charge manipulation in optimizing the adsorption performance of GO. This study establishes a simple and effective approach for synthesizing GO-cationic polymer composites, contributing to the development of advanced materials for water purification applications. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 60 76 2024 Investigating the radical properties of oxidized carbon materials under photo-irradiation: behavior of carbon radicals and their application in catalytic reactions 10544 10547 EN Md Razu Ahmed Research Institute for Interdisciplinary Science, Okayama University Israel Ortiz Anaya Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Oxidized carbon materials have abundant surface functional groups and customizable properties, making them an excellent platform for generating radicals. Unlike reactive oxygen species such as hydroxide or superoxide radicals that have been reported previously, oxidized carbon also produces stable carbon radicals under photo-irradiation. This has been confirmed through electron spin resonance. Among the various oxidized carbon materials synthesized, graphene oxide shows the largest number of carbon radicals when exposed to blue LED light. The light absorption capacity, high surface area, and unique structural characteristics of oxidized carbon materials offer a unique function for radical-mediated oxidative reactions. No potential conflict of interest relevant to this article was reported.

Springer Nature Singapore Acta Medica Okayama 0302-9743 2025 RKPM: Restricted Kernel Page Mechanism to Mitigate Privilege Escalation Attacks 213 231 EN Hiroki Kuzuno Graduate School of Engineering, Kobe University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Kernel memory corruption attacks against operating systems exploit kernel vulnerabilities to overwrite kernel data. Kernel address space layout randomization makes it difficult to identify kernel data by randomizing their virtual address space. Control flow integrity (CFI) prevents unauthorized kernel code execution by verifying kernel function calls. However, these countermeasures do not prohibit writing to kernel data. If the virtual address of privileged information is specified and CFI is circumvented, the privileged information can be modified by a kernel memory corruption attack. In this paper, we propose a restricted kernel page mechanism (RKPM) to mitigate kernel memory corruption attacks by introducing restricted kernel pages to protect the kernel data specified in the kernel. The RKPM focuses on the fact that kernel memory corruption attacks attempt to read the virtual addresses around the privileged information. The RKPM adopts page table mapping handling and a memory protection key to control the read and write restrictions of the restricted kernel pages. This allows us to mitigate kernel memory corruption attacks by capturing reads to the restricted kernel page before the privileged information is overwritten. As an evaluation of the RKPM, we confirmed that it can mitigate privilege escalation attacks on the latest Linux kernel. We also measured that there was a certain overhead in the kernel performance. This study enhances kernel security by mitigating privilege escalation attacks through the use of software or hardware based restricted kernel pages. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2024 kdMonitor: Kernel Data Monitor for Detecting Kernel Memory Corruption 66 73 EN Hiroki Kuzuno Graduate School of Engineering, Kobe University Toshihiro Yamauchi Okayama University,Faculty of Environmental, Life, Natural Science and Technology Privilege escalation attacks through memory corruption via kernel vulnerabilities pose significant threats to operating systems. Although the extended Berkley Packet Filter has been employed to trace kernel code execution by inserting interrupts before and after kernel code invocations, it does not track operations before and after kernel data writes, thus hindering effective kernel data monitoring. In this study, we introduce a kernel data monitor (kdMonitor), which is a novel security mechanism designed to detect unauthorized alterations in the monitored kernel data of a dedicated kernel page. The kdMonitor incorporates two distinct methods. The first is periodic monitoring which regularly outputs the monitored kernel data of the dedicated kernel pages. The second is dynamic monitoring, which restricts write access to a dedicated kernel page, supplements any write operations with page faults, and outputs the monitored kernel data of dedicated kernel pages. kdMonitor enables real-time tracking of specified kernel data of the dedicated kernel page residing in the kernel's virtual memory space from the separated machine. Using kdMonitor, we demonstrated its capability to pinpoint tampering with user process privileged information stemming from privilege escalation attacks on the kernel. Through an empirical evaluation, we validated the effectiveness of kdMonitor in detecting privilege escalation attacks by user processes on Linux. Performance assessments revealed that kdMonitor achieved an attack detection time of 0.83 seconds with an overhead of 0.726 %. No potential conflict of interest relevant to this article was reported.

Springer Nature Switzerland Acta Medica Okayama 0302-9743 2023 vkTracer: Vulnerable Kernel Code Tracing to Generate Profile of Kernel Vulnerability 222 234 EN Hiroki Kuzuno Graduate School of Engineering, Kobe University Toshihiro Yamauchi Faculty of Natural Science and Technology, Okayama University Vulnerable kernel codes are a threat to an operating system kernel. An adversary’s user process can forcefully invoke a vulnerable kernel code to cause privilege escalation or denial of service (DoS). Although service providers or security operators have to determine the effect of kernel vulnerabilities on their environment to decide the kernel updating, the list of vulnerable kernel codes are not provided from the common vulnerabilities and exposures (CVE) report. It is difficult to identify the vulnerable kernel codes from the exploitation result of the kernel which indicates the account information or the kernel suspension. To identify the details of kernel vulnerabilities, this study proposes a vulnerable kernel code tracer (vkTracer), which employs an alternative viewpoint using proof-of-concept (PoC) code to create a profile of kernel vulnerability. vkTracer traces the user process of the PoC code and the running kernel to hook the invocation of the vulnerable kernel codes. Moreover, vkTracer extracts the whole kernel component’s information using the running and static kernel image and debug section. The evaluation results indicated that vkTracer could trace PoC code executions (e.g., privilege escalation and DoS), identify vulnerable kernel codes, and generate kernel vulnerability profiles. Furthermore, the implementation of vkTracer revealed that the identification overhead ranged from 5.2683 s to 5.2728 s on the PoC codes and the acceptable system call latency was 3.7197 μs. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0040-4039 169 2025 Recent progress on phenothiazine organophotoredox catalysis 155745 EN Kenta Tanaka Research Institute for Interdisciplinary Science, Okayama University Hiroyoshi Takamura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Isao Kadota Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Photoredox catalysis has garnered significant attention in recent years due to its broad applicability in visible-light-induced organic transformations. While significant progress has been made in the development of highly oxidizing catalysts, such as acridinium catalysts, there remains a notable shortage of strongly reducing organophotoredox catalysts. Phenothiazines are widely used as photoredox catalysts owing to their unique redox potentials, particularly their low excited-state oxidation potentials (Eox* = −1.35 V to −3.51 V vs. SCE). Thus, they can be applied to a variety of photoredox reactions with oxidative-quenching cycles, and effectively reduce various organic molecules, such as aryl and alkyl halides, alkenes, malonyl peroxides, cobalt complexes, and redox-active esters. Due to their unique properties, this review focuses on the recent advances in phenothiazine organophotoredox catalysis. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2574-0962 8 13 2025 Microagglomerate of VO2 Particles Packing Paraffin Wax Using Capillary Force as a Latent Thermal Energy Storage Medium 9595 9603 EN Kazuma Isobe Faculty of Environmental, Life, Natural Science and Technology, Okayama University Kaketo Yamauchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yutaka Yamada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Akihiko Horibe Faculty of Environmental, Life, Natural Science and Technology, Okayama University This study proposed a material to retain paraffin wax with vanadium dioxide (VO2) particles as a latent thermal energy storage medium, an alternative to core–shell microcapsules containing phase change materials. VO2 microparticles, which were synthesized through a sol–gel method and annealing process, were dispersed in the oil-in-water microemulsion to obtain microagglomerates of VO2 microparticles. The average diameter of microagglomerates was 5 μm, and they retained paraffin wax at the vacancies among VO2 particles. Although the microagglomerates had no complete shells similar to core–shell microcapsules, the microagglomerates successfully trapped paraffin wax droplets without any leakage even in a high-temperature environment. It was because capillary forces acting among VO2 particles strictly prevented any leakage of paraffin waxes. The differential scanning calorimetry revealed that the microagglomerates contained only 16.5 wt % of n-octadecane, used as a paraffin wax. However, since VO2 particles can release or absorb latent heat due to their metal–insulator phase transition, the proposed microagglomerates exhibited higher thermal energy storage densities than phase change microcapsules whose shells do not show phase transitions. Moreover, the microagglomerates exhibited higher thermal conductivity than microcapsules with amorphous inorganic shells because the VO2 particles were crystallized through annealing. The proposed microagglomerate is a promising form for further improving the thermal energy storage density and thermal performance of the latent thermal energy storage medium, especially in the temperature range of 30 to 70 °C. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2041-6520 16 26 2025 Collective motions in the primary coordination sphere: a critical functional framework for catalytic activity of the oxygen-evolving complex of photosystem II 12024 EN Hiroshi Isobe Takayoshi Suzuki Research Institute for Interdisciplinary Science, Okayama University Michihiro Suga Research Institute for Interdisciplinary Science, Okayama University Jian-Ren Shen Research Institute for Interdisciplinary Science, Okayama University Kizashi Yamaguchi Center for Quantum Information and Quantum Biology, Osaka University Photosynthetic water oxidation, vital for dioxygen production and light energy conversion, is catalyzed by the oxygen-evolving complex of photosystem II, where the inorganic Mn4CaO5 cluster acts as the catalytic core. In this study, we investigate the functional significance of collective motions of amino acid side chains within the primary coordination sphere of the Mn cluster, focusing on their role in modulating the energetic demands for catalytic transformations in the S3 state. We applied regularized canonical correlation analysis to quantitatively correlate the three-dimensional arrangement of coordinating atoms with catalytic driving forces computed via density functional theory. Our analysis reveals that distinct collective side chain motions profoundly influence the energetic requirements for structural reconfigurations of the Mn cluster, achieved through expansion and contraction of the ligand cavity while fine-tuning its geometry to stabilize key intermediates. Complementary predictions from a neural network-based machine learning model indicate that the coordination sphere exerts a variable energetic impact on the catalytic transformations of the Mn cluster, depending on the S-state environment. Integrated computational analyses suggest that the extended lifetime of the S3YZ˙ state, consistently observed after three flash illuminations, may result from slow, progressive protein dynamics that continuously reshape the energy landscape, thereby shifting the equilibrium positions of rapid, reversible chemical processes over time. Overall, our findings demonstrate that collective motions in the primary coordination sphere constitute an active, dynamic framework essential for the efficient execution of multi-electron catalysis under ambient conditions, while simultaneously achieving a high selectivity with irreversible nature required for effective 3O2 evolution. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2056-306X 11 1 2025 Effect of temperature cycles on the sleep-like state in Hydra vulgaris 2 EN Aya Sato Faculty of Arts and Science, Kyushu University Manabu Sekiguchi Graduate School of Natural Science and Technology, Okayama University Koga Nakada Graduate School of Systems Life Sciences, Kyushu University Taishi Yoshii Graduate School of Natural Science and Technology, Okayama University Taichi Q. Itoh Faculty of Arts and Science, Kyushu University Background Sleep is a conserved physiological phenomenon across species. It is mainly controlled by two processes: a circadian clock that regulates the timing of sleep and a homeostat that regulates the sleep drive. Even cnidarians, such as Hydra and jellyfish, which lack a brain, display sleep-like states. However, the manner in which environmental cues affect sleep-like states in these organisms remains unknown. In the present study, we investigated the effects of light and temperature cycles on the sleep-like state in Hydra vulgaris.<br> Results Our findings indicate that Hydra responds to temperature cycles with a difference of up to 5° C, resulting in decreased sleep duration under light conditions and increased sleep duration in dark conditions. Furthermore, our results reveal that Hydra prioritizes temperature changes over light as an environmental cue. Additionally, our body resection experiments show tissue-specific responsiveness in the generation ofthe sleep-like state under different environmental cues. Specifically, the upper body can generate the sleep-like state in response to a single environmental cue. In contrast, the lower body did not respond to 12-h light–dark cycles at a constant temperature.<br> Conclusions These findings indicate that both light and temperature influence the regulation of the sleep-like state in Hydra. Moreover, these observations highlight the existence of distinct regulatory mechanisms that govern patterns of the sleep-like state in brainless organisms, suggesting the potential involvement of specific regions for responsiveness of environmental cues for regulation of the sleep-like state. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2041-1723 15 1 2024 A high-protein diet-responsive gut hormone regulates behavioral and metabolic optimization in Drosophila melanogaster 10819 EN Yuto Yoshinari Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University Takashi Nishimura Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University Taishi Yoshii Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Shu Kondo Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science Hiromu Tanimoto Graduate School of Life Sciences, Tohoku University Tomoe Kobayashi Division of Molecular Genetics, Shigei Medical Research Institute Makoto Matsuyama Division of Molecular Genetics, Shigei Medical Research Institute Ryusuke Niwa Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba Protein is essential for all living organisms; however, excessive protein intake can have adverse effects, such as hyperammonemia. Although mechanisms responding to protein deficiency are well-studied, there is a significant gap in our understanding of how organisms adaptively suppress excessive protein intake. In the present study, utilizing the fruit fly, Drosophila melanogaster, we discover that the peptide hormone CCHamide1 (CCHa1), secreted by enteroendocrine cells in response to a high-protein diet (HPD), is vital for suppressing overconsumption of protein. Gut-derived CCHa1 is received by a small subset of enteric neurons that produce short neuropeptide F, thereby modulating protein-specific satiety. Importantly, impairment of the CCHa1-mediated gut-enteric neuronal axis results in ammonia accumulation and a shortened lifespan under HPD conditions. Collectively, our findings unravel the crosstalk of gut hormone and neuronal pathways that orchestrate physiological responses to prevent and adapt to dietary protein overload. No potential conflict of interest relevant to this article was reported.

SAGE Publications Acta Medica Okayama 0748-7304 2025 Neurotransmitter and Receptor Mapping in Drosophila Circadian Clock Neurons via T2A-GAL4 Screening EN Ayumi Fukuda Graduate School of Natural Science and Technology, Okayama University Aika Saito Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taishi Yoshii Graduate School of Environmental, Life, Natural Science and Technology, Okayama University The circadian neuronal network in the brain comprises central pacemaker neurons and associated input and output pathways. These components work together to generate coherent rhythmicity, synchronize with environmental time cues, and convey circadian information to downstream neurons that regulate behaviors such as the sleep/wake cycle. To mediate these functions, neurotransmitters and neuromodulators play essential roles in transmitting and modulating signals between neurons. In Drosophila melanogaster, approximately 240 brain neurons function as clock neurons. Previous studies have identified several neurotransmitters and neuromodulators, including the Pigment-dispersing factor (PDF) neuropeptide, along with their corresponding receptors in clock neurons. However, our understanding of the neurotransmitters and receptors involved in the circadian system remains incomplete. In this study, we conducted a T2A-GAL4-based screening for neurotransmitter and receptor genes expressed in clock neurons. We identified 2 neurotransmitter-related genes and 22 receptor genes. Notably, while previous studies had reported the expression of 6 neuropeptide receptor genes in large ventrolateral neurons (l-LNv), we also found that 14 receptor genes―including those for dopamine, serotonin, and γ-aminobutyric acid―are expressed in l-LNv neurons. These findings suggest that l-LNv neurons serve as key integrative hubs within the circadian network, receiving diverse external signals. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0039-9140 297 2026 Microfluidic paper-based analytical devices for antioxidant vitamins C and E in foods 128540 EN Mana Kawahara Department of Chemistry, Okayama University Kaewta Danchana Department of Chemistry, Okayama University Takashi Kaneta Department of Chemistry, Okayama University In this study, we developed microfluidic paper-based analytical devices (μPADs) for the determination of antioxidant vitamins. The proposed μPADs utilize the reduction of metal ions by hydrophilic and hydrophobic antioxidant vitamins, which is followed by colorimetric reactions with chelating reagents. Hydrophilic vitamin C reduces Fe(III) to Fe(II) and forms a stable Fe(II)-bathophenanthroline complex in an aqueous solution. By contrast, this complex is unstable in organic solvents, and hydrophobic vitamin E requires Fe(III) and bathophenanthroline to be replaced with Cu(II) and bathocuproine. In these results, the relationship between the logarithm of a vitamin's concentration and its color intensity was linear and ranged from 4.4 to 35 mg L−1 for ascorbic acid and 50–200 mg L−1 for α-tocopherol. The limits of detection, estimated from the standard deviation of blank samples, were 3.1 mg L−1 for ascorbic acid and either 27 mg L−1 (in hexane) or 48 mg L−1 (in ethanol) for α-tocopherol. The proposed method was used to quantify vitamin C in bell peppers, mandarin oranges, kiwifruit, and lemons, as well as vitamin E in almonds, almond milk, and dietary supplements. The results demonstrate the effectiveness of these μPADs for the practical analysis of antioxidant vitamins in food samples. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0910-6340 2025 Innovations in paper-based analytical devices and portable absorption photometers for onsite analysis EN Sasikarn Seetasang Department of Chemistry, Faculty of Science and Technology, Thammasat University Mika I. Umeda Department of Chemistry, Okayama University Jianchao Ren Department of Chemistry, Okayama University Takashi Kaneta Department of Chemistry, Okayama University Two types of analytical instruments and devices―one sophisticated high-performance instrument and another portable device―have been the focus of recent trends in analytical science. The necessity of point-of-care testing and onsite analysis has accelerated the advancement of high-performance, user-friendly portable analytical devices such as paper-based analytical devices (PADs) and light-emitting diode-based portable photometers. In this review, we summarize our achievements in the study of PADs and portable photometers. Several types of PADs are capable of performing titrations, metal ion analysis, and food analysis, while photometers, which consist of paired emitter–detector light-emitting diode (PEDD) photometers, are used for thiocyanate and herbicide analysis. These PADs and photometers permit the onsite determination of real environmental, body fluid, and food samples when an equipped laboratory is unavailable. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0960-9822 35 12 2025 Oxytocin facilitates human touch-induced play behavior in rats 2916 2926.e3 EN Himeka Hayashi Department of Biology, Faculty of Environmental, Life, Natural Science and Technology, Okayama University, Sayaka Tateishi Ushimado Marine Institute (UMI), Faculty of Environmental, Life, Natural Science and Technology, Okayama University Ayumu Inutsuka Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University Sho Maejima Ushimado Marine Institute (UMI), Faculty of Environmental, Life, Natural Science and Technology, Okayama University Daisuke Hagiwara Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, German Center for Psychiatry (DZPG), Medical Faculty Mannheim, University of Heidelberg Yasuo Sakuma Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Nippon Medical School Tatsushi Onaka Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University Valery Grinevich Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, German Center for Psychiatry (DZPG), Medical Faculty Mannheim, University of Heidelberg Hirotaka Sakamoto Department of Biology, Faculty of Environmental, Life, Natural Science and Technology, Okayama University, Pleasant touch sensations play a fundamental role in social bonding, yet the neural mechanisms underlying affinity-like behaviors remain poorly understood. Here, we demonstrate that juvenile-adolescent rats, which naturally engage in social play with peers characterized by rough-and-tumble interactions and 50 kHz ultrasonic vocalizations indicating pleasant sensations, develop a strong affinity for human hands through similar playful contact achieved by repeated tickling with human hands. Using this rat with tickling-induced high affinity for human hands, we discovered that repeated tickling mimicking rough-and-tumble play led to increased oxytocin receptor (OTR) expression in the ventrolateral part of the ventromedial hypothalamus (VMHvl). Inhibition of oxytocin signaling in the VMHvl reduced affinity-like behaviors from rats to human hands. These findings suggest that OTR neurons in VMHvl play an important role in the increase in affinity for human hands induced by pleasant touch sensation with human touch-induced play behavior. Based on retrograde and anterograde tracing studies examining the supraoptic nucleus (SON) and the paraventricular nucleus (PVN) as primary sources of oxytocin, we demonstrate that a subset of oxytocin fibers in the VMHvl originate from the SON, suggesting that affinity-like behavior from rats to human hands may be controlled by oxytocin signaling from magnocellular neurons. Together, this work advances our understanding of how oxytocin shapes social behavior and may inform the development of therapeutic strategies to promote positive social interactions. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 2772-4174 13 2025 Photochemical internalization of mRNA using a photosensitizer and nucleic acid carriers 100242 EN Hayaki Maemoto Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Ryohei Suzaki Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kazunori Watanabe Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University Keiji Itaka Department of Biofunction Research, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University Takashi Ohtsuki Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University mRNA has great potential for therapeutic applications because it can encode a variety of proteins and antigens, in addition to advantages over DNA in terms of gene expression without genomic integration, nuclear localization, or transcription. However, therapeutic applications of mRNA require safe and effective delivery into target cells. Therefore, we aimed to investigate photochemical internalization (PCI) as a promising strategy for delivering mRNA to target cells. In this strategy, mRNA is taken up into cells by endocytosis, accumulates in endosomes, and is released in a light-dependent manner from the endosomes using an endosome-accumulating photosensitizer, aluminum phthalocyanine disulfonate (AlPcS2a), in combination with nucleic acid carrier molecules. We compared the efficacy of various nucleic acid carriers, including branched polyethyleneimine (bPEI) and poly{N'-[N-(2-aminoethyl)-2-aminoethyl] aspartamide} (PAsp(DET)) under the same conditions for PCI-based mRNA delivery. Our results indicated that bPEI and PAsp(DET) at low N/P ratios exhibited efficient light-enhancement of mRNA expression by PCI with AlPcS2a. Notably, bPEI exhibited the highest light-dependent mRNA delivery among the carriers evaluated (including cationic polymers, cationic peptides, and lipids), whereas PAsp(DET) showed promise for clinical use because of its lower toxicity compared with bPEI. This PCI strategy allows effective cytosolic mRNA delivery at low N/P ratios, thereby reducing cationic carrier molecule-induced cytotoxicity. This method allows spatiotemporal control of protein expression and holds potential for novel light-dependent mRNA therapies. Overall, this study provided valuable insights into optimizing mRNA delivery systems for therapeutic applications. No potential conflict of interest relevant to this article was reported.

日本エアロゾル学会 Acta Medica Okayama 0912-2834 40 2 2025 水溶性高分子含有スラリー液滴乾燥過程の評価 99 108 EN Koichi Nakaso Faculty of Environmental, Life, Natural Science and Technology, Okayama University Daichi Yamashita Graduate School of Natural Science and Technology, Okayama University Yutaro Aoyama Graduate School of Natural Science and Technology, Okayama University Yasushi Mino Faculty of Environmental, Life, Natural Science and Technology, Okayama University Kuniaki Gotoh Faculty of Environmental, Life, Natural Science and Technology, Okayama University The granulation process of a slurry droplet containing a water-soluble polymer in a spray dryer is investigated. Although there have been many studies on the drying behavior of a single-component slurry droplet, there have been few reports for a multicomponent slurry droplet. This is due to the complexity and difficulty in evaluating the drying behavior of a multicomponent slurry droplet. Therefore, for the production of granules from multicomponent materials by a spray dryer, its operating conditions are usually determined by trial and error. To optimize the practical granule production process, the drying behavior of multicomponent slurry droplets should be studied. In this study, the drying behavior of a silica slurry droplet containing polyvinyl alcohol (PVA) is investigated. The drying behavior of a droplet suspended on the tip of a needle was observed. The effect of the volume fraction of PVA on the drying behavior and the morphology of a dried granule is studied. The effect of drying condition on the granule formation process is also investigated. As a result, the structure of dried granules was strongly influenced by PVA concentration. Segregation of PVA in the dried granules was observed. Based on the results, the drying process diagram is presented. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1433-7851 2025 Development of a Vinylated Cyclic Allene: A Fleeting Strained Diene for the Diels–Alder Reaction e202510319 EN Haruki Mizoguchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Takumi Obata Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taiki Hirai Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Manaka Komatsu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Akira Sakakura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Fleeting molecules possessing strained multiple bonds are important components in organic synthesis due to their ability to undergo various chemical reactions driven by the release of strain energy. Although the use of strained π-bonds as 2π components, represented by dienophiles in Diels–Alder reactions, has been well studied, “the strained diene (4π component) approach” for molecular construction remains underexplored. Herein, we report the design of a vinyl cyclic allene (1-vinyl-1,2-cyclohexadiene) as a highly reactive strained diene and the development of its Diels–Alder reactions. Experimental and computational studies of vinyl cyclic allenes revealed that this diene system undergoes cycloaddition with dienophiles regio- and stereoselectively under mild reaction conditions. These studies also provide insight into the reactivity and selectivity of the system. The strained diene approach enables the convergent construction of polycyclic molecules through bond disconnections distinct from conventional retrosynthetic analysis, thus offering an efficient strategy for the assembly of functional molecules. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Towards SBOM-based Access Control for Transparent and Explicit Program Execution EN Yuta Shimamoto Okayama University Hiroyuki Uekawa NTT Social Informatics Laboratories Mitsuaki Akiyama NTT Social Informatics Laboratories Toshihiro Yamauchi Okayama University Although a Software Bill of Materials (SBOM) plays a key role in software transparency, inconsistencies in SBOM descriptions can undermine its value. To address this, we propose a novel approach to program access control, SBOMAC, which leverages Mandatory Access Control (MAC) systems to ensure transparent and explicit program execution. In this study, we identify the challenges associated with implementing this approach and present preliminary investigation results to address these challenges. No potential conflict of interest relevant to this article was reported.

日本機械学会 Acta Medica Okayama 2187-9761 91 946 2025 ボールエンドミルの突き出し長さに応じた切削条件補正システムの開発 24-00128 EN Hiroyuki KODAMA Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuki MORIYA Graduate school of Environmental, Life, Natural Science and Technology, Okayama University Tatsuo MORIMOTO Graduate school of Environmental, Life, Natural Science and Technology, Okayama University Kazuhito OHASHI Faculty of Environmental, Life, Natural Science and Technology, Okayama University In the field of die and mold machining, determining appropriate cutting conditions is crucial. Factors such as tool geometry, machining path, work material characteristics, machining efficiency, and finishing accuracy must be taken into consideration. However, the current method of determining cutting conditions relies heavily on the intuition and experience of skilled engineers, and there is a need for a system to replace such knowledge. One of the critical factors affecting machining accuracy and efficiency is the tool overhang length, which is directly related to tool geometry. Unfortunately, there is no clear guideline for its determination. In a previous study, researchers developed a system to quickly derive cutting conditions using a data mining method and Random Forest Regression (RFR) applied to a tool catalog database. In this study, we constructed a new cutting condition compensation system based on the existing model, which accounts for the tool overhang length. The results of cutting experiments under high aspect ratio overhang lengths confirm that the correction coefficients proposed by the system are significant. No potential conflict of interest relevant to this article was reported.

Fuji Technology Press Ltd. Acta Medica Okayama 1883-8022 19 3 2025 Study on the Grinding Temperature of Workpiece in Side Plunge Grinding Process 337 345 EN Lingxiao Gao Graduate School of Natural Science and Technology, Okayama University Motoki Kuida Graduate School of Natural Science and Technology, Okayama University Hiroyuki Kodama Faculty of Environmental, Life, Natural Science and Technology, Okayama University Kazuhito Ohashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Grinding is used to finish thrust metal attachment parts, such as crankshafts, which have both journal and thrust surfaces. In side plunge grinding, a thrust surface and a cylindrical surface of a shaft workpiece with collars are finished in a single plunge grinding process. However, the surface quality near the ground internal corner, where grinding fluid may not penetrate, can deteriorate, causing high residual stress and cracks owing to grinding heat. While it has been reported that quality issues at the inner corners of the ground surface can be mitigated by reducing the grinding point temperature through efficient cooling fluid supply, the mechanisms of grinding phenomena and heat generation in side plunge grinding are not yet fully understood. In this study, the variations in the grinding temperature at the thrust surface of a workpiece with a collar were experimentally investigated using a wire/workpiece thermocouple to clarify these phenomena. The results revealed a significant increase in the grinding temperature at the corners of the grinding zone. However, it slightly decreases as the thermocouple output approaches the center of the workpiece, indicating a slight effect of the grinding speed. The surface temperature of the workpiece in side plunge grinding is primarily influenced by the wheel depth-of-cut in the thrust direction. Additionally, the effect of workpiece rotational speed and grinding infeed speed on temperature distribution has been demonstrated. No potential conflict of interest relevant to this article was reported.

Springer International Publishing Acta Medica Okayama 0302-9743 2022 CyNER: Information Extraction from Unstructured Text of CTI Sources with Noncontextual IOCs 85 104 EN Shota Fujii Graduate School of Natural Science and Technology, Okayama University Nobutaka Kawaguchi Research & Development Group, Hitachi, Ltd. Tomohiro Shigemoto Research & Development Group, Hitachi, Ltd. Toshihiro Yamauchi Faculty of Natural Science and Technology, Okayama University Cybersecurity threats have been increasing and growing more sophisticated year by year. In such circumstances, gathering Cyber Threat Intelligence (CTI) and following up with up-to-date threat information is crucial. Structured CTI such as Structured Threat Information eXpression (STIX) is particularly useful because it can automate security operations such as updating FW/IDS rules and analyzing attack trends. However, as most CTIs are written in natural language, manual analysis with domain knowledge is required, which becomes quite time-consuming.<br> In this work, we propose CyNER, a method for automatically structuring CTIs and converting them into STIX format. CyNER extracts named entities in the context of CTI and then extracts the relations between named entities and IOCs in order to convert them into STIX. In addition, by using key phrase extraction, CyNER can extract relations between IOCs that lack contextual information, such as those listed at the bottom of a CTI, and named entities. We describe our design and implementation of CyNER and demonstrate that it can extract named entities with the F-measure of 0.80 and extract relations between named entities and IOCs with the maximum accuracy of 81.6%. Our analysis of structured CTI showed that CyNER can extract IOCs that are not included in existing reputation sites, and that it can automatically extract IOCs that have been exploited for a long time and across multiple attack groups. CyNER is thus expected to contribute to the efficiency of CTI analysis. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2832-1324 2023 Analyzing Post-injection Attacker Activities in IoT Devices: A Comprehensive Log Analysis Approach 292 297 EN Hervet Victor Okayama University Satoru Kobayashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University With the continuous proliferation of Internet of Things (IoT) devices, malware threats that specifically target these devices continue to increase. The urgent need for robust security measures is predicated on a comprehensive understanding of the behavioral patterns of IoT malware. However, previous studies have often overlooked the analysis of command sequences in Telnet logs. This study bridges this research gap by examining the post-injection behaviors of attackers. By analyzing a vast dataset comprising more than ten million logs collected from an IoT honeypot, we reveal three distinct post-injection activity patterns, each with unique characteristics. These patterns provide pivotal insights that not only help distinguish between legitimate operations and attempted attacks, but also drive the development of robust cybersecurity measures that effectively deter such behaviors. The nuances discovered in this study contribute significantly to IoT security by enhancing our understanding of malware tactics and informing targeted defense strategies. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2832-1324 2023 Prevention Method for Stack Buffer Overflow Attack in TA Command Calls in OP-TEE 274 278 EN Kaito Shiba Graduate School of Natural Science and Technology, Okayama University Hiroki Kuzuno Graduate School of Engineering, Kobe University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University TEE systems provide normal world and secure world. It is impossible to gain access to the secure world directly from the normal world. However, vulnerabilities in the secure world can cause attacks to compromise the secure world. In this study, we investigate the security features applied to trusted applications (TA) in OP-TEE and clarify the lack of protection against stack buffer overflow in TA command calls. We also propose a method for preventing attacks that exploit stack buffer overflows in TA command calls. In addition, the experimental results show that attacks on the vulnerable TAs can be prevented with the proposed method and the overhead can be evaluated. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2379-1896 2023 Evaluation of Effectiveness of MAC Systems Based on LSM for Protecting IoT Devices 161 167 EN Masato Miki Graduate School of Natural Science and Technology, Okayama University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Satoru Kobayashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Numerous active attacks targeting Internet of Things (IoT) devices exist. They exploit the latest vulnerabilities discovered in IoT devices. Therefore, Mandatory Access Control (MAC) systems based on Linux Security Modules (LSM), such as SELinux and AppArmor, are effective security features for IoT devices because they can mitigate the impact of attacks even if software vulnerabilities are discovered. However, they are not adopted by most IoT devices. The existing approaches are insufficient for investigating the causes of this problem.In this study, we comprehensively investigated what factors can affect the applicability of MAC systems based on LSM in IoT devices. We focused on how frequently cases can occur where they cannot be adopted, owing to each factor. To increase the comprehensiveness of the factors affecting the adoption of MAC systems in IoT devices, we investigated the kernel version, CPU architecture, and support for BusyBox in addition to the investigation of resources, which conducted in previous studies. We also conducted simulated experiments based on the attack method of Mirai to investigate whether MAC systems can protect against IoT malware. Finally, we discuss the impact of a combination of these factors on MAC system adoption. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2833-2350 2023 Non Real-Time Data Transmission Performance Analysis of PROFINET for Assuring Data Transmission Quality 236 244 EN Takashi Norimatsu Graduate School of Natural Science and Technology, Okayama University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University The industrial Ethernet PROFINET supports three different data transmission modes: isochronous real-time (IRT), real-time (RT), and non real-time (NRT) transmitting data requiring hard, soft, and no real-time performances, respectively. The data transmission latency in the NRT increased with the amount of data transmission in the IRT, RT, and NRT. Therefore, the quality of data transmission in NRT may degrade as the amount of data transmission in IRT, RT, and NRT increases. In this study, we derived the average data transmission latency in an NRT with data transmission in IRT and RT by applying stochastic processes. This allowed us to maintain the quality of data transmission in the NRT by adjusting the number of devices connected to the network and the number of applications transmitting data in the NRT so that the average latency of data in the NRT does not exceed a certain value. No potential conflict of interest relevant to this article was reported.

IEEE Acta Medica Okayama 2832-1324 2023 Supporting Multiple OS Types on Estimation of System Call Hook Point by Virtual Machine Monitor 267 273 EN Masaya Sato Okayama Prefectural University Taku Omori Okayama Prefectural University Toshihiro Yamauchi Okayama University Hideo Taniguchi Okayama University Methods to hook system calls issued by a guest operating system (OS) running on a virtual machine using a virtual machine monitor are proposed. The address of the hook point is derived from the guest OS’s source code and established prior to the kernel startup process. Due to changes in system call processing in OS updates and address space layout randomization, the addresses of these hook points cannot always be pre-determined before the kernel startup process. To address this challenge, a method for estimating the system call hook point is proposed in Linux by analyzing the guest OS memory on x86-64 CPUs rather than pre-calculation. Although the method supports Linux, the method can be extended to support other OS types. In this paper, we propose a method to extend the method to support additional OSes. Specifically, we present analysis results and a novel method for estimating hook points on FreeBSD, NetBSD, and OpenBSD. The effectiveness of our proposed method is also demonstrated through evaluation. No potential conflict of interest relevant to this article was reported.

Springer Nature Switzerland Acta Medica Okayama 2367-4512 2025 Investigation Towards Detecting Landing Websites for Fake Japanese Shopping Websites 107 119 EN Daigo Michishita Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Satoru Kobayashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Toshihiro Yamauchi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Recently, the number of victims of fake shopping websites that imitate legitimate ones to defraud people has been increasing. It has been shown that fake shopping websites use legitimate defaced landing websites as their leading paths. Therefore, if the detection of landing websites for fake shopping websites can be achieved, it can assist in addressing these websites and reduce the opportunities for users to be redirected to fake shopping websites. In this study, we collect and investigate existing landing websites that redirect users to fake Japanese shopping websites and identify effective features for detecting them. We identified effective search terms for collecting landing websites for fake Japanese shopping websites and found that using Google searches with queries of top-level domain and product names was effective. We also investigated the conditions for activating analytical evasion functions in the collected landing websites for fake Japanese shopping websites and clarified the differences in search results between crawlers and users. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1523-7060 2025 Transformation of α,β-Unsaturated Aldehydes with a Small Amount of Electricity: Cyanosilylation, Isomerization, and Nucleophilic Addition EN Mayu Fujii Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nanaho Ueno Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Koichi Mitsudo Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University An electrochemical method was developed to convert α,β-unsaturated aldehydes into carboxylic acid derivatives via cyanosilylation, isomerization, and nucleophilic addition. This reaction is more sustainable than the usual electrochemical organic reaction because this reaction proceeds catalytically with active species generated by a very small amount of electricity. Furthermore, scale-up synthesis with a flow reactor has been achieved. No potential conflict of interest relevant to this article was reported.

The Endocrine Society Acta Medica Okayama 1945-7170 166 8 2025 Neuromedin U Deficiency Disrupts Daily Testosterone Fluctuation and Reduces Wheel-running Activity in Rats bqaf102 EN Mai Otsuka Graduate School of Natural Science and Technology, Okayama University Yu Takeuchi Graduate School of Natural Science and Technology, Okayama University Maho Moriyama Graduate School of Natural Science and Technology, Okayama University Sakura Egoshi Department of Biology, Faculty of Science, Okayama University Yuki Goto Graduate School of Natural Science and Technology, Okayama University Tingting Gu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Atsushi P Kimura Department of Biological Sciences, Faculty of Science, Hokkaido University Shogo Haraguchi Department of Biochemistry, Showa University School of Medicine Taishi Yoshii Graduate School of Natural Science and Technology, Okayama University Sakae Takeuchi Graduate School of Natural Science and Technology, Okayama University Makoto Matsuyama Division of Molecular Genetics, Shigei Medical Research Institute George E Bentley Department of Integrative Biology and Helen Wills Neuroscience Institute, University of California at Berkeley Sayaka Aizawa Graduate School of Natural Science and Technology, Okayama University The objective of this study was to elucidate the role of endogenous Neuromedin U (NMU) in rats by performing NMU knockout (KO). Male, but not female NMU KO rats exhibited decreased wheel-running activity vs wildtype (WT), although overall home cage activity was not affected. Plasma testosterone in WT rats varied significantly over the course of a day, with a peak at ZT1 and a nadir at ZT18, whereas in NMU KO rats testosterone remained stable throughout the day. Chronic administration of testosterone restored wheel-running activity in NMU KO rats to the same level as in WT rats, suggesting that the decrease in wheel-running activity in NMU KO rats is due to the disruption of the diurnal change of testosterone. Accordingly, expression of the luteinizing hormone beta subunit (Lhb) mRNA in the pars distalis of anterior pituitary was significantly lower in NMU KO rats; immunostaining revealed that the size of luteinizing hormone (LH)–expressing cells was also relatively small in those animals. In the brain of male WT rats, Nmu was highly expressed in the pars tuberalis, and the NMU receptor Nmur2 was highly expressed in the ependymal cell layer of the third ventricle. This study reveals a novel function of NMU and indicates that endogenous NMU in rats plays a role in the regulation of motivated activity via regulation of testosterone. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0021-9797 695 2025 Tunable interlayer distance in graphene oxide through alkylamine surface coverage and chain length 137727 EN Israel Ortiz-Anaya Graduate School of Natural Sciences and Technology, Okayama University Seiji Obata Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Layered materials have unique structures that can be modified by adjusting the space between layers through pillaring or surface functionalization. Unlike typical crystalline layered materials, graphene oxide (GO) possesses reactive oxygenated functional groups, which lead to spontaneous reduction and stacking upon thermal treatment. Here, we investigated the functionalization of GO with different amounts of hexylamine to control the degree of surface coverage. Furthermore, octylamine and dodecylamine were employed to confirm the effect of the alkyl chain length on the interlayer distance of the resultant GO derivatives. Subsequent thermal treatment produced reduced GO (rGO) functionalized with alkylamines, demonstrating the retention of the interlayer distance. Additionally, amine-functionalized rGOs exhibited varying porous structures. No potential conflict of interest relevant to this article was reported.

eLife Sciences Publications, Ltd Acta Medica Okayama 2050-084X 13 2024 Structural basis for molecular assembly of fucoxanthin chlorophyll a/c-binding proteins in a diatom photosystem I supercomplex RP99858 EN Koji Kato Research Institute for Interdisciplinary Science and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yoshiki Nakajima Research Institute for Interdisciplinary Science and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Jian Xing Graduate School of Agriculture, Kyoto University Minoru Kumazawa Graduate School of Agriculture, Kyoto University Haruya Ogawa Research Institute for Interdisciplinary Science and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Jian-Ren Shen Research Institute for Interdisciplinary Science and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kentaro Ifuku Graduate School of Agriculture, Kyoto University Ryo Nagao Faculty of Agriculture, Shizuoka University Photosynthetic organisms exhibit remarkable diversity in their light-harvesting complexes (LHCs). LHCs are associated with photosystem I (PSI), forming a PSI-LHCI supercomplex. The number of LHCI subunits, along with their protein sequences and pigment compositions, has been found to differ greatly among the PSI-LHCI structures. However, the mechanisms by which LHCIs recognize their specific binding sites within the PSI core remain unclear. In this study, we determined the cryo-electron microscopy structure of a PSI supercomplex incorporating fucoxanthin chlorophyll a/c-binding proteins (FCPs), designated as PSI-FCPI, isolated from the diatom Thalassiosira pseudonana CCMP1335. Structural analysis of PSI-FCPI revealed five FCPI subunits associated with a PSI monomer; these subunits were identified as RedCAP, Lhcr3, Lhcq10, Lhcf10, and Lhcq8. Through structural and sequence analyses, we identified specific protein–protein interactions at the interfaces between FCPI and PSI subunits, as well as among FCPI subunits themselves. Comparative structural analyses of PSI-FCPI supercomplexes, combined with phylogenetic analysis of FCPs from T. pseudonana and the diatom Chaetoceros gracilis, underscore the evolutionary conservation of protein motifs crucial for the selective binding of individual FCPI subunits. These findings provide significant insights into the molecular mechanisms underlying the assembly and selective binding of FCPIs in diatoms. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Visible-Light-Responsive Nanocarbon Catalyst for Radical-Mediated Organic Transformations EN MD RAZU AHMED Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Observation of the Radiative Decay from the Isomeric State of Thorium-229 EN Koichi OKAI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 和歌山県紀伊半島の四万十帯の美山付加コンプレックスと竜神付加コンプレックスにおける構造性メランジュの未固結から岩石化初期の剪断変形構造に関する研究 EN Norito TAKESUE Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 The evolutionary contextualization and deep neural network modeling on fruit ripening response EN Eriko KUWADA Graduate School of Environmental, Life, Natural Science and Technology, Okayama University No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Analysis of Protein Toxicity and Cellular Phenotypes Triggered by the Maximum Overexpression of Proteins in Yeast EN Shotaro NAMBA Graduate School of Environmental, Life, Natural Science and Technology, Okayama University No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Tuning the 3D Structure of Graphene Oxide Assembly for Precisely Controlled Adsorption Properties EN ISRAEL ORTIZ ANAYA Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Development of synthetic methods for complex molecular frameworks via 1,2-rearrangement reactions EN Hidetoshi KAMADA Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Deeper Mechanistic Understanding of Some Reaction Processes in Electroorganic Synthesis EN Yuta NIKI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 高性能ワイヤ放電加工のための油加工液特性の最適化に関する研究 EN Shixian LIU Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 組紐製造技術による繊維強化型人工筋肉の製作手法の確立と変位センシングの実現 EN WEIHANG TIAN Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 数理統計学と情報理論を用いた限定的な事前情報下での意思決定補助手法に関する研究 EN Shuto TANABASHI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Bandgap tuning of halide perovskite materials using crystal structure changes associated with B-site metal cation substitution EN THIRI HTUN Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Implementations of Web Application Systems for Docker Image Generation and Flutter Programming Exercise Answer EN LYNN HTET AUNG Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 A Study of Hand Gestures for Controlling Video Games in Rehabilitation Exergame System EN RADHIATUL HUSNA Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Enhancements of Active Access-Point Configuration for IEEE 802.11n 2.4GHz Wireless Local-Area Network EN Mousumi Saha Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Social Factors in Motion: Quantifying the Dynamics of Dyad–Individual Collision Avoidance EN Adrien Thibaud Marie GREGORJ Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 A Study on Information Security for End-to-End Communication by TCP/IP Internet Protocol Suite EN Takashi NORIMATSU Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Synthesis and Properties of Benzothiadiazole-Based Organic Photovoltaic Donor Materials EN Yi YAN Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Palladium-Catalyzed Decarbonylative Halogenation of Carboxylic Acid Derivatives EN Tian TIAN Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Molecular Simulation and Integral Equation Studies of the Solute-Solute Effective Interactions in Water and Simple Liquids EN Hidefumi NAITO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 MOLECULAR SIMULATION STUDY ON AQUEOUS SOLUTIONS OF ALCOHOLS AND PNIPAM WITH DEVELOPMENT OF ION MODELS EN Aoi TAIRA Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Sexually dimorphic behavior and its hormonal regulation in rodents EN Himeka HAYASHI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Development of Enzyme Activity Assays Based on Spectrometric Methods and Paper-Based Analytical Devices EN JIANCHAO REN Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Development of on-site environmental analytical methods for nitrogen compounds using microfluidic paper-based analytical devices EN Mika UMEDA (ISOYAMA) Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Structural Design of Nanoporous Materials with Substance Formation on Two-Dimensional Materials Using Calcination EN Yuki TAKEUCHI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 炭素材料の内部状態解析に向けた固体NMR観測手法の革新と応用 EN Hideka ANDO Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Synthesis and characterization of novel nanoporous carbons using graphene oxide EN Zhao LI Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Design of the full-sky scanning strategy and systematic effect control in a cosmic microwave background probe EN Yusuke TAKASE Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0039-9140 295 2025 Using a microfluidic paper-based analytical device and solid-phase extraction to determine phosphate concentration 128303 EN Kaewta Danchana Department of Chemistry, Okayama University Haruka Namba Department of Chemistry, Okayama University Takashi Kaneta Department of Chemistry, Okayama University Phosphate is an essential nutrient, but in high concentrations it contributes to water pollution. Traditional methods for phosphate measurement, such as absorption spectrophotometry and ion chromatography, require expensive equipment and skilled operators. This study introduces a microfluidic paper-based analytical device (μPAD) that is designed to accomplish field-based, low-concentration phosphate measurements. This μPAD utilizes colorimetric detection based on the molybdenum blue method. Herein, we describe how the conditions were optimized in terms of design and sensitivity by adjusting reagent concentrations, paper thickness, and the time frames for sample introduction, and reaction. The operation consists of simply dipping the μPAD into a sample, capturing images in a home-made photo studio box, and processing the images with ImageJ software to measure RGB intensity. An additional preconcentration step involves solid-phase extraction with an anion exchange resin that achieves a 10-fold enrichment, which enables detection that ranges from 0.05 to 1 mg L−1 with a detection limit of 0.089 mg L−1 and a quantification limit of 0.269 mg L−1. The replicated measurements showed good reproducibility both intraday and interday (five different days) as 4.7 % and 3.0 % of relative standard deviations, respectively. After storage in a refrigerator for as long as 26 days, this μPAD delivered stable and accurate results for real-world samples of natural water, soil, and toothpaste. The results produced using this system correlate well with those produced via spectrophotometry. This μPAD-based method is a cost-effective, portable, rapid, and simple approach that allows relatively unskilled operators to monitor phosphate concentrations in field applications. No potential conflict of interest relevant to this article was reported.

American Association for the Advancement of Science Acta Medica Okayama 2375-2548 11 20 2025 Structure of a photosystem I supercomplex from Galdieria sulphuraria close to an ancestral red alga eadv7488 EN Koji Kato Research institute for interdisciplinary Science and Graduate School of environ-mental, life, natural Science and technology, Okayama University Minoru Kumazawa Graduate School of Agriculture, Kyoto University Yoshiki Nakajima Research institute for interdisciplinary Science and Graduate School of environ-mental, life, natural Science and technology, Okayama University Takehiro Suzuki Biomolecular characterization Unit, RiKen center for Sustainable Resource Science Naoshi Dohmae Biomolecular characterization Unit, RiKen center for Sustainable Resource Science Jian-Ren Shen Research institute for interdisciplinary Science and Graduate School of environ-mental, life, natural Science and technology, Okayama University Kentaro Ifuku Graduate School of Agriculture, Kyoto University Ryo Nagao Faculty of Agriculture, Shizuoka University Red algae exhibit unique photosynthetic adaptations, characterized by photosystem I (PSI) supercomplexes containing light-harvesting complexes (LHCs), forming PSI-LHCI supercomplexes. In this study, we solved the PSI-LHCI structure of Galdieria sulphuraria NIES-3638 at 2.19-angstrom resolution using cryo-electron microscopy, revealing a PSI monomer core associated with seven LHCI subunits. Structural analysis uncovered the absence of phylloquinones, the common secondary electron acceptor in PSI of photosynthetic organisms, suggesting adaptation to a benzoquinone-like molecule. Phylogenetic analysis suggests that G. sulphuraria retains traits characteristic of an ancestral red alga, including distinctive LHCI binding and interaction patterns. Variations in LHCI composition and interactions across red algae, particularly in red-lineage chlorophyll a/b-binding-like protein and red algal LHCs, highlight evolutionary divergence and specialization. These findings not only deepen our understanding of red algal PSI-LHCI diversification but also enable us to predict features of an ancestral red algal PSI-LHCI supercomplex, providing a framework to explore evolutionary adaptations from an ancestral red alga. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2041-1723 16 1 2025 Structure of a photosystem II-FCPII supercomplex from a haptophyte reveals a distinct antenna organization 4175 EN Romain La Rocca Research Institute for Interdisciplinary Science, and Advanced Research Field, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Koji Kato Research Institute for Interdisciplinary Science, and Advanced Research Field, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Pi-Cheng Tsai Research Institute for Interdisciplinary Science, and Advanced Research Field, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yoshiki Nakajima Research Institute for Interdisciplinary Science, and Advanced Research Field, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Fusamichi Akita Research Institute for Interdisciplinary Science, and Advanced Research Field, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Jian-Ren Shen Research Institute for Interdisciplinary Science, and Advanced Research Field, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Haptophytes are unicellular algae that produce 30 to 50% of biomass in oceans. Among haptophytes, a subset named coccolithophores is characterized by calcified scales. Despite the importance of coccolithophores in global carbon fixation and CaCO3 production, their energy conversion system is still poorly known. Here we report a cryo-electron microscopic structure of photosystem II (PSII)-fucoxanthin chlorophyll c-binding protein (FCPII) supercomplex from Chyrostila roscoffensis, a representative of coccolithophores. This complex has two sets of six dimeric and monomeric FCPIIs, with distinct orientations. Interfaces of both FCPII/FCPII and FCPII/core differ from previously reported. We also determine the sequence of Psb36, a subunit previously found in diatoms and red algae. The principal excitation energy transfer (EET) pathways involve mainly 5 FCPIIs, where one FCPII monomer mediates EET to CP47. Our findings provide a solid structural basis for EET and energy dissipation pathways occurring in coccolithophores. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1523-7060 27 18 2025 Electrochemical Oxidation of Benzyl Alcohols via Hydrogen Atom Transfer Mediated by 2,2,2-Trifluoroethanol 4737 4741 EN Takahiro Kawajiri API R&D Laboratory, Research Division, Shionogi & Co., Ltd. Masahiro Hosoya API R&D Laboratory, Research Division, Shionogi & Co., Ltd. Satoshi Goda API R&D Laboratory, Research Division, Shionogi & Co., Ltd. Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University We report a novel electrochemical oxidation of benzyl alcohols. We found that trifluoroethanol plays a role as a hydrogen atom transfer (HAT) mediator, enabling the oxidation of electron-deficient substrates that are difficult to directly oxidize on electrode surfaces. Density functional theory calculations, cyclic voltammetry measurements, and constant potential electrolysis studies supported the proposed HAT mechanism. Moreover, the obtained carbonyl compounds could be functionalized in an electrochemical one-pot manner, further highlighting their synthetic utility. No potential conflict of interest relevant to this article was reported.

岡山大学理学部地球科学科 Acta Medica Okayama 1340-7414 31 1 2025 南西諸島の前弧域における付加体を含む堆積層のモデル化 1 15 EN Masanao KOMATSU Okayama Gakuin University Sohei URAKAMI Formerly Department of Earth Sciences, Okayama University Taro OKAMOTO Department of Earth and Planetary Sciences, School of Science, Institute of Science Tokyo Hiroshi TAKENAKA Department of Earth Sciences, Okayama University 10.18926/ESR/68676 　We combine the recent seismic reflection profiles to construct a new seismic velocity model of the sedimentary layer incorporating the accretionary prism along the Ryukyu trench. In constructing the new model, we refer to the zoning (ZONE1 to ZONE4) identified by Okamura et al. (2017, Tectonophys.). The construction process consists of the following steps: First, we digitize either unconformities or VP=4 to 5 km/s lines as the seismic basement, whichever is more clearly identifiable. Second, the digitized thickness data of the sedimentary layer from the reflection profiles are geometrically modeled and interpolated to make the three-dimensional structure model. Finally, we supplement the external region of the constructed 3-D sedimentary model using the J-SHIS model provided by the NIED to complete the velocity structure model in the entire Ryukyu arc. The main features of our model are as follows: In ZONE1, off Ishigaki-jima island, the thick sedimentary layer extends about 50 km wide from the Ryukyu trench. In ZONE2, off Miyako-jima island, the thinner layer compared to the other zones is found near the trench, with a thin sedimentary terrace covering the area behind it. In ZONE3, off Okinawa-jima island, the sedimentary layer deepens as it approaches the trench. In ZONE4, off Tokara islands, the deepest layer among all zones is identified. We then conduct 3-D finite-difference simulations of seismic wave propagation using the new and the previous models to confirm the improvement of the new model. In the simulations, the effects of the accretionary prism along the Ryukyu trench on the seismic wave propagation are clearly identified. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2227-7080 13 4 2025 An Implementation of Creep Test Assisting System with Dial Gauge Needle Reading and Smart Lighting Function for Laboratory Automation 139 EN Dezheng Kong Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nobuo Funabiki Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Shihao Fang Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Mitsuhiro Noprianto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Mitsuhiro Okayasu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Pradini Puspitaningayu Department of Electrical Engineering, Universitas Negeri Surabaya For decades, analog dial gauges have been essential for measuring and monitoring data at various industrial instruments including production machines and laboratory equipment. Among them, we focus on the instrument for creep test in a mechanical engineering laboratory, which evaluates material strength under sustained stress. Manual reading of gauges imposes significant labor demands, especially in long-duration tests. This burden further increases under low-lighting environments, where poor visibility can lead to misreading data points, potentially compromising the accuracy of test results. In this paper, to address the challenges, we implement a creep test assisting system that possesses the following features: (1) to save the installation cost, a web camera and Raspberry Pi are employed to capture images of the dial gauge and automate the needle reading by image processing in real time, (2) to ensure reliability under low-lighting environments, a smart lighting mechanism is integrated to turn on a supplementary light when the dial gauge is not clearly visible, and (3) to allow a user to stay in a distant place from the instrument during a creep test, material break is detected and the corresponding message is notified to a laboratory staff using LINE automatically. For evaluations, we install the implemented system into a material strength measuring instrument at Okayama University, Japan, and confirm the effectiveness and accuracy through conducting experiments under various lighting conditions. No potential conflict of interest relevant to this article was reported.

Informa UK Limited Acta Medica Okayama 0737-3937 43 6 2025 Spray-drying of polymer solutions across a broad concentration range and the subsequent formation of a few micro- ∼nano-meter sized fibers 1108 1116 EN Chika Araga Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Kaito Fukushima Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Haruna Sato Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Nao Honda Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Takato Hasegawa Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Koichi Nakaso Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Naoyuki Ishida Department of Chemical Engineering and Material Sciences, Faculty of Science and Engineering, Doshisha University Koreyoshi Imamura Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University Spray drying is a widely utilized technique for the concentration and fine particulation of dried products. This study demonstrated that a versatile spray dryer, equipped with a two-fluid nozzle atomizer, can convert polymer solutions into nanoscale fibers by manipulating the conditions of the polymer solutions. The polymers employed in this research included polyvinylpyrrolidones (Mw 24.5 k to 60 kDa), dextrans (70 k to 450–650 kDa), pullulan, gum Arabic, Eudragit and agar, with methanol and water serving as solvents. Various combinations of polymers and solvents were subjected to spray drying at polymer concentrations ranging from 5 to 1000 g/L. Scanning electron microscopy analyses of the spray-dried samples indicated that the products transitioned from micrometer-sized particles to sub-micrometer fibers in several instances when the polymer concentrations exceeded specific threshold levels. The investigation also explored the relationship between these threshold concentrations and the surface tension and viscosity of the polymer solutions. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1424-8220 25 7 2025 Length Estimation of Pneumatic Artificial Muscle with Optical Fiber Sensor Using Machine Learning 2221 EN Yilei Ni Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Shuichi Wakimoto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Weihang Tian Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuichiro Toda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Takefumi Kanda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Daisuke Yamaguchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University A McKibben artificial muscle is a soft actuator driven by air pressure, characterized by its flexibility, lightweight design, and high power-to-weight ratio. We have developed a smart artificial muscle that is capable of sensing its motion. To enable this sensing function, an optical fiber was integrated into the sleeve consisting of multiple fibers and serving as a component of the McKibben artificial muscle. By measuring the macrobending loss of the optical fiber, the length of the smart artificial muscle is expected to be estimated. However, experimental results indicated that the sensor's characteristics depend not only on the length but also on the load and the applied air pressure. This dependency arises because the stress applied to the optical fiber increases, causing microbending loss. In this study, we employed a machine learning model, primarily composed of Long Short-Term Memory (LSTM) neural networks, to estimate the length of the smart artificial muscle. The experimental results demonstrate that the length estimation obtained through machine learning exhibits a smaller error. This suggests that machine learning is a feasible approach to enhancing the length measurement accuracy of the smart artificial muscle. No potential conflict of interest relevant to this article was reported.

AIP Publishing Acta Medica Okayama 0034-6748 96 3 2025 Development of density measurement at high pressure and high temperature using the x-ray absorption method combined with laser-heated diamond anvil cell 033907 EN Hidenori Terasaki Department of Earth Sciences, Okayama University Hiroyuki Kamina Department of Earth Sciences, Okayama University Saori I. Kawaguchi Japan Synchrotron Radiation Research Institute, SPring-8 Tadashi Kondo Department of Earth and Space Science, Osaka University Ko Morioka Department of Earth Sciences, Okayama University Ryo Tsuruoka Department of Earth and Space Science, Osaka University Moe Sakurai Department of Earth Sciences, Okayama University Akira Yoneda Department of Earth and Space Science, Osaka University Seiji Kamada AD Science Incorporation Naohisa Hirao Japan Synchrotron Radiation Research Institute, SPring-8 The densities of liquid materials at high pressures and high temperatures are important information to understand the elastic behavior of liquids at extreme conditions, which is closely related to the formation and evolution processes of the Earth and planetary interiors. The x-ray absorption method is an effective method to measure the density of non-crystalline materials at high pressures. However, the temperature condition of the x-ray absorption method using a diamond anvil cell (DAC) has been limited to 720 K to date. To significantly expand the measurable temperature condition of this method, in this study, we developed a density measurement technique using the x-ray absorption method in combination with a laser-heated DAC. The density of solid Ni was measured up to 26 GPa and 1800 K using the x-ray absorption method and evaluated by comparison with the density obtained from the x-ray diffraction. The density of solid Ni with a thickness >17 μm was determined with an accuracy of 0.01%–2.2% (0.001–0.20 g/cm3) and a precision of 0.8%–1.8% (0.07–0.16 g/cm3) in the x-ray absorption method. The density of liquid Ni was also determined to be 8.70 ± 0.15–8.98 ± 0.38 g/cm3 at 16–23 GPa and 2230–2480 K. Consequently, the temperature limit of the x-ray absorption method can be expanded from 720 to 2480 K by combining it with a laser-heated DAC in this study. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1999-5903 17 3 2025 Facial Privacy Protection with Dynamic Multi-User Access Control for Online Photo Platforms 124 EN Andri Santoso Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Samsul Huda Green Innovation Center, Okayama University Yuta Kodera Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yasuyuki Nogami Graduate School of Environmental, Life, Natural Science and Technology, Okayama University In the digital age, sharing moments through photos has become a daily habit. However, every face captured in these photos is vulnerable to unauthorized identification and potential misuse through AI-powered synthetic content generation. Previously, we introduced SnapSafe, a secure system for enabling selective image privacy focusing on facial regions for single-party scenarios. Recognizing that group photos with multiple subjects are a more common scenario, we extend SnapSafe to support multi-user facial privacy protection with dynamic access control designed for online photo platforms. Our approach introduces key splitting for access control, an owner-centric permission system for granting and revoking access to facial regions, and a request-based mechanism allowing subjects to initiate access permissions. These features ensure that facial regions remain protected while maintaining the visibility of non-facial content for general viewing. To ensure reproducibility and isolation, we implemented our solution using Docker containers. Our experimental assessment covered diverse scenarios, categorized as "Single", "Small", "Medium", and "Large", based on the number of faces in the photos. The results demonstrate the system's effectiveness across all test scenarios, consistently performing face encryption operations in under 350 ms and achieving average face decryption times below 286 ms across various group sizes. The key-splitting operations maintained a 100% success rate across all group configurations, while revocation operations were executed efficiently with server processing times remaining under 16 ms. These results validate the system's capability in managing facial privacy while maintaining practical usability in online photo sharing contexts. No potential conflict of interest relevant to this article was reported.

Beilstein-Institut Acta Medica Okayama 1860-5397 21 2025 Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra 670 679 EN Yuuki Ishii Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Minoru Yamaji Division of Molecular Science, Graduate School of Science and Engineering, Gunma University Fumito Tani Institute for Materials Chemistry and Engineering, Kyushu University Kenta Goto Institute for Materials Chemistry and Engineering, Kyushu University Yoshihiro Kubozono Research Institute for Interdisciplinary Science, Okayama University Hideki Okamoto Graduate School of Environmental, Life, Natural Science and Technology, Okayama University [n]Phenacenes ([n] = 5-7), octafluorinated at the terminal benzene rings (F8-phenacenes: F8PIC, F8FUL, and F87PHEN), were photochemically synthesized, and their electronic spectra were investigated to reveal the effects of the fluorination on the electronic features of phenacene molecules. F8-Phenacenes were conveniently synthesized by the Mallory photoreaction of the corresponding fluorinated diarylethenes as the key step. Upon fluorination on the phenacene cores, the absorption and fluorescence bands of the F8-phenacenes in CHCl3 systematically red-shifted by ca. 3-5 nm compared to those of the corresponding parent phenacenes. The vibrational progressions of the absorption and fluorescence bands were little affected by the fluorination in the solution phase. In the solid state, the absorption band of F8-phenacenes appeared in the similar wavelength region for the corresponding parent phenacenes whereas their fluorescence bands markedly red-shifted and broadened. These observations suggest that the intermolecular interactions of excited-state F8-phenacene molecules are significantly different from those of the corresponding parent molecules, most likely due to different crystalline packing motifs. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2045-2322 15 1 2025 Local-structure insight into the improved superconducting properties of Pb-substituted La(O, F)BiS2: a photoelectron holography study 8366 EN Yajun Li Graduate School of Natural Science and Technology, Okayama University Yusuke Hashimoto Nara Institute of Science and Technology (NAIST) Noriyuki Kataoka Graduate School of Natural Science and Technology, Okayama University Zexu Sun Nara Institute of Science and Technology (NAIST) Sota Kawamura Nara Institute of Science and Technology (NAIST) Hiroto Tomita Nara Institute of Science and Technology (NAIST) Taro Setoguchi Graduate School of Natural Science and Technology, Okayama University Soichiro Takeuchi Nara Institute of Science and Technology (NAIST) Shunjo Koga Nara Institute of Science and Technology (NAIST) Kohei Yamagami Japan Synchrotron Radiation Research Institute (JASRI) Yoshinori Kotani Japan Synchrotron Radiation Research Institute (JASRI) Satoshi Demura Department of Physics, College of Science and Technology(CST), Nihon University Kanako Noguchi Tokyo University of Science Hideaki Sakata Tokyo University of Science Tomohiro Matsushita Nara Institute of Science and Technology (NAIST) Takanori Wakita Graduate School of Natural Science and Technology, Okayama University Yuji Muraoka Graduate School of Natural Science and Technology, Okayama University Takayoshi Yokoya Graduate School of Natural Science and Technology, Okayama University Pb-substituted La(O, F)BiS2 (Pb-LaOFBiS2) exhibits improved superconducting properties and a resistivity anomaly around 100 K that is attributed to a structural transition. We have performed temperature(T)-dependent photoelectron holography (PEH) to study dopant incorporation sites and the local structure change across the anomaly. The PEH study of Pb-LaOFBiS2 provided evidence for the dominant incorporation sites of Pb and F: Pb atoms are incorporated into the Bi sites and F atoms are incorporated into the O site. No remarkable difference in the local structures around Pb and Bi atoms was observed. Across the temperature of the resistivity anomaly (T*), photoelectron holograms of Bi 4f changed. Comparisons of holograms with those of non-substituted LaOFBiS2 sample, as well as simulated holograms, suggested that (1), above T*, the tetragonal structure of Pb-LaOFBiS2 is different from the tetragonal structure of LaOFBiS2 and (2), below T*, the tetragonal structure still remains in Pb-LaOFBiS2. We discuss a possible origin of the difference in the structure above T* and the implication of the result below T*, which are necessary ingredients to understand the physical properties of Pb-LaOFBiS2. No potential conflict of interest relevant to this article was reported.

Taylor and Francis Group Acta Medica Okayama 1559-2316 20 1 2025 Specific enhancement of the translation of thermospermine-responsive uORF-containing mRNAs by ribosomal mutations in Arabidopsis thaliana 2480231 EN Koki Mutsuda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuichi Nishii Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tomohiko Toyoshima Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroko Fukushima Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroyasu Motose Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Taku Takahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Auxin-induced xylem formation in angiosperms is negatively regulated by thermospermine, whose biosynthesis is also induced by auxin. In Arabidopsis thaliana, loss-of-function mutants of ACL5, which encodes thermospermine synthase, exhibit a dwarf phenotype accompanied by excessive xylem formation. Studies of suppressor mutants that recover from the acl5 dwarf phenotype suggest that thermospermine alleviates the inhibitory effect of an upstream open-reading frame (uORF) on the main ORF translation of SAC51 mRNA. Many suppressor mutations for acl5 have been mapped to the uORF conserved in the SAC51 family or to ribosomal protein genes, such as RPL10A, RPL4A, and RACK1A. In this study, we identified newly isolated acl5 suppressors, sac501, sac504, and sac506, which are additional alleles of RPL10A and the uORFs of SAC51 family members, SACL1 and SACL3, respectively. To investigate whether acl5-suppressor alleles of ribosomal genes broadly affect translation of uORF-containing mRNAs, we examined GUS activity in several 5'-GUS fusion constructs. Our results showed that these alleles enhanced GUS activity in SAC51 and SACL3 5'-fusion constructs but had no effect on other 5'-fusion constructs unrelated to thermospermine response. This suggests that these ribosomal proteins are specifically involved in the thermospermine-mediated regulation of mRNA translation. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 0743-7463 41 11 2025 Droplet Impact Behavior on Convex Surfaces with a Circumferential Wettability Difference 7640 7647 EN Taku Ishikawa Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yutaka Yamada Faculty of Environmental, Life, Natural Science and Technology, Okayama University Kazuma Isobe Faculty of Environmental, Life, Natural Science and Technology, Okayama University Akihiko Horibe Faculty of Environmental, Life, Natural Science and Technology, Okayama University Controlling the bouncing behavior of the impacting droplets is an important issue for splay cooling, icing prevention, and other applications. The bouncing behavior of impacting droplets on superhydrophobic curved surfaces and flat substrates with a wettability difference has been widely investigated, and droplets impacting these surfaces show shorter contact times than those on superhydrophobic flat surfaces and droplet transport. However, there have been few studies on the droplet impact behavior on curved surfaces with a wettability difference, where efficient droplet control could be achieved by combining the features. In the present study, droplet impact experiments were conducted using copper cylinders with different circumferential wettabilities from hydrophilic to superhydrophobic, varying the impact velocity, cylinder diameter, and rotation angle. Droplets that impacted the wettability boundary showed asymmetric deformation and moved to the hydrophilic side, owing to the driving force of the wettability difference. Moreover, the droplet behavior was classified into four types: the droplet bounced off the surface, the droplet bounced off the surface and split, the droplet attached to the surface, and the droplet attached to the surface and split. The droplet behavior was estimated by using the maximum spreading width of the droplet impacted on the flat substrate. We evaluated whether the droplets attached to the surface or bounced off the surface after impact using the Weber number and rotation angle, and the estimations were in agreement with the experimental results for cylinder diameters of 4 and 6 mm. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2041-1723 16 1 2025 Keratinocyte-driven dermal collagen formation in the axolotl skin 1757 EN Ayaka Ohashi Graduate School of Environment, Life, Natural Science and Technology, Okayama University Hirotaka Sakamoto Graduate School of Environment, Life, Natural Science and Technology, Okayama University Junpei Kuroda Graduate School of Frontier Biosciences, Osaka University Yohei Kondo Center for One Medicine Innovative Translational Research (COMIT), Nagoya University Yasuhiro Kamei Laboratory for Biothermology, National Institute for Basic Biology Shigenori Nonaka The Graduate University for Advanced Studies (SOKENDAI) Saya Furukawa Graduate School of Environment, Life, Natural Science and Technology, Okayama University Sakiya Yamamoto Graduate School of Environment, Life, Natural Science and Technology, Okayama University Akira Satoh Graduate School of Environment, Life, Natural Science and Technology, Okayama University Type I collagen is a major component of the dermis and is formed by dermal fibroblasts. The development of dermal collagen structures has not been fully elucidated despite the major presence and importance of the dermis. This lack of understanding is due in part to the opacity of mammalian skin and it has been an obstacle to cosmetic and medical developments. We reveal the process of dermal collagen formation using the highly transparent skin of the axolotl and fluorescent collagen probes. We clarify that epidermal cells, not dermal fibroblasts, contribute to dermal collagen formation. Mesenchymal cells (fibroblasts) play a role in modifying the collagen fibers already built by keratinocytes. We confirm that collagen production by keratinocytes is a widely conserved mechanism in other model organisms. Our findings warrant a change in the current consensus about dermal collagen formation and could lead to innovations in cosmetology and skin medication. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0026-265X 210 2025 A microfluidic paper-based analytical device that uses gelatin film to assay protease activity via time readout 112952 EN Jianchao Ren Department of Chemistry, Okayama University Kaewta Danchana Department of Chemistry, Okayama University Takashi Kaneta Department of Chemistry, Okayama University Food processing, detergents, and pharmaceuticals frequently employ proteases, which are enzymes that break the chemical bonds of both proteins and peptides. In this work, we developed a microfluidic paper-based analytical device (µPAD) for protease activity assays via time readout. To accomplish this, we folded the µPAD to form layers, then inserted a water-insoluble gelatin film between the layers of paper to form the device. Lamination helps to maintain the gelatin film between the introduction zone, which is the upper layer, and the detection channel, which is the lower layer. Proteases decompose the gelatin film when it enters the introduction zone, which then allows it to flow into the detection channel. The protease activity in the sample solution determines the time required to dissolve the gelatin film, which leads to a linear relationship between the logarithm of the protease concentration and the time required to flow the solution a specific distance on the detection channel. The µPAD was used to measure proteases in concentrations that ranged from 0.25 to 1 mg L−1 for bromelain, 2.5 to 10 mg L−1 for papain, and 1 to 8 mg L−1 for trypsin. The limits of quantification for bromelain, papain, and trypsin were 0.41, 2.7, and 9.2 mg mL−1, respectively. The relative standard deviations for bromelain were smaller than 2 % for concentrations ranging from 0.5 to 1.0 mg L−1. We compared the µPAD to a commercially available protease activity assay kit, which relies on quenching fluorescein isothiocyanate-labeled casein. Both methods demonstrated the same order of activity: bromelain > papain > trypsin. The proposed device allowed the assay of bromelain in both pineapple pulp and juice, which were stored at room temperature. When first using the proposed device, the bromelain in the pulp gradually lost its activity, while the activity of the bromelain in the juice showed no significant change for five days. The µPAD requires no analytical instruments for quality control and monitoring of the protease activity in food. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 61 25 2025 Recent development of azahelicenes showing circularly polarized luminescence 4757 4773 EN Chihiro Maeda Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Tadashi Ema Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Recently, a variety of circularly polarized luminescence (CPL) dyes have been developed as next-generation chiroptical materials. Helicenes, ortho-fused aromatics, have been recognized as some of the most promising CPL dyes. Although typical carbohelicenes show CPL, weak fluorescence is often emitted in the blue region. In contrast, heteroatom-embedded helicenes (heterohelicenes) can show intense fluorescence and CPL in the visible region because heteroatoms alter the electronic states of helicene frameworks. Among various heterohelicenes, nitrogen-embedded helicenes (azahelicenes) have unique features such as facile functionalization and sensitive responses to acid/base or metal ions. Furthermore, polycyclic aromatic hydrocarbons (PAHs) containing azaborine units have been recognized as excellent luminescent materials, and the helical derivatives, B,N-embedded helicenes, have been rapidly growing recently. In this feature article, we review and summarize the synthesis and chiroptical properties of azahelicenes, which are classified into imine-type and amine-type azahelicenes and B,N-embedded helicenes. CPL switching systems of azahelicenes are also reviewed. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2076-3417 15 5 2025 Deep Reinforcement Learning for Dynamic Pricing and Ordering Policies in Perishable Inventory Management 2421 EN Yusuke Nomura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Ziang Liu Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tatsushi Nishi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Perishable goods have a limited shelf life, and inventory should be discarded once it exceeds its shelf life. Finding optimal inventory management policies is essential since inefficient policies can lead to increased waste and higher costs. While many previous studies assume the perishable inventory is processed following the First In, First Out rule, it does not reflect customer purchasing behavior. In practice, customers' preferences are influenced by the shelf life and price of products. This study optimizes inventory and pricing policies for a perishable inventory management problem considering age-dependent probabilistic demand. However, introducing dynamic pricing significantly increases the complexity of the problem. To tackle this challenge, we propose eliminating irrational actions in dynamic programming without sacrificing optimality. To solve this problem more efficiently, we also implement a deep reinforcement learning algorithm, proximal policy optimization, to solve this problem. The results show that dynamic programming with action reduction achieved an average of 63.1% reduction in computation time compared to vanilla dynamic programming. In most cases, proximal policy optimization achieved an optimality gap of less than 10%. Sensitivity analysis of the demand model revealed a negative correlation between customer sensitivity to shelf lives or prices and total profits. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0022-0396 429 2025 Polyhedral entire solutions in reaction-diffusion equations 529 565 EN Masaharu Taniguchi Research Institute for Interdisciplinary Science, Okayama University This paper studies polyhedral entire solutions to a bistable reaction-diffusion equation in Rn. We consider a pyramidal traveling front solution to the same equation in Rn+1. As the speed goes to infinity, its projection converges to an n-dimensional polyhedral entire solution. Conversely, as the time goes to -infinity, an n-dimensional polyhedral entire solution gives n-dimensional pyramidal traveling front solutions. The result in this paper suggests a correlation between traveling front solutions and entire solutions in general reaction-diffusion equations or systems. No potential conflict of interest relevant to this article was reported.