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A NEW DYNAMIC CORROSION TEST FOR DENTAL materials

DENTAL materials 1989年第6期5卷 411-414页

作者： MELETIS, EI GIBBS, CA LIAN, K Louisiana State University Materials Science Engineering Program Mechanical Engineering Department Baton Rouge LA 70803-6413 United States University of California Biomedical Engineering Graduate Group Davis CA 95616 United States

A new laboratory technique has been developed in an effort to simulate the deterioration processes occurring in dental amalgam restorations while they are exposed to attack by the oral environment and simultaneously subjected to biting forces during mastication. This combined mechanical wear and corrosion action may be one of the major contributors to the degradation of dental amalgam restorations. The technique provides the capability of varying and measuring electrochemical and mechanical parameters during a sliding-wear process in a corrosive environment. A high-copper dental amalgam was selected and tested to demonstrate the applicability of the method in evaluating and studying the effects of the combined action of wear and corrosion processes on dental materials. For the particular amalgam material tested in the present study, it was found that sliding-wear significantly lowered its corrosion potential and increased corrosion rates by at least one order of magnitude.

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Influences of secondary and tertiary amines in epoxy resins on water dynamics by all-atomic molecular dynamics simulations

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Chemical Physics 2025年 597卷

作者： Yuji Higuchi Yasuyuki Nakamura Masanobu Naito Yoshihisa Fujii Research Institute for Information Technology Kyushu University 744 Motooka Nishi-ku Fukuoka 819-0395 Fukuoka Japan Research Center for Macromolecules and Biomaterials National Institute for Materials Science Sengen 1-2-1 Tsukuba 305-0047 Ibaraki Japan Department of Chemistry for Materials Graduate School of Engineering Mie University 1577 Kurimamachiya-cho Tsu 514-8507 Mie Japan

All-atomic molecular dynamics simulations were conducted to elucidate the water dynamics around amines in epoxy resins. The rotational relaxation and translational diffusion of water molecules were slow in an epoxy resin based on a secondary amine, compared with those in one based on a tertiary amine. This qualitatively agrees with experimental quasielastic neutron scattering results, demonstrating the validity of the simulations. For the tertiary amine, water cluster formation accelerated the rotational relaxation of water, while the secondary amines attracted water molecules slightly more strongly than tertiary amines, preventing water from forming large clusters and slowing down translational diffusion.

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Correlations between water quality and precipitation in areas with different levels of human occupation

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International Journal of Energy and Water Resources 2021年第1期5卷 25-31页

作者： Rodrigues, Lucas Augusto Pereira Radomski, Fernando Aparecido Dias Godoy, Rodrigo Felipe Bedim Trevisan, Elias Crisigiovanni, Enzo Luigi Department of Environment State University of Maringá Maringá-PR Brazil Graduate Program in Materials Science and Engineering Federal University of Paraná Curitiba-PR Brazil Graduate Program in Forest Sciences Unicentro Guarapuava-PR Brazil

Riverine water is largely used for human consumption and it is well known that its quality is correlated to many external factors. Because of that, this study evaluated linear correlations between precipitation and several water quality parameters using data collected from Antas’ river (Paraná, Brazil) at locations with different levels of human occupation aiming to identify water quality irregularities related to these important external factors, especially at a point surrounded by preserved vegetation. The statistical analyses were made using Pearson’s linear correlation coefficient (r) and the open source programming software, R. The results showed that precipitation has moderate to strong correlation with turbidity, true color, total coliforms and E. coli (0.99 ≥ r ≥ 0.44), and also has weak to moderate correlations with pH (− 0.39 ≥ r ≥ − 0.58) and biochemical oxygen demand (0.48 ≥ r ≥ 0.36), regardless of the level of human occupation nearby. The high correlations observed for E. coli and total coliforms in an area protected by native vegetation, probably due to adjacent rural activities, represents a novel and major finding. Dissolved oxygen and temperature showed no significant correlations with rainfall volume (0.26 ≥ r ≥ − 0.19). Since Brazilian law ensures that water quality parameters must be measured and considered in projects of water resources management, the proposed methodology seems to be promising for government policies applications, since it comprises only simple analyzes and a free software for simulations. © Islamic Azad University (IAU) 2021.

关键词： Hydrology R software Rainfall Spatial data Statistical analysis

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Front Cover: Potassium Carbonate as a Low-Cost and Highly Active Solid Base Catalyst for Low-Temperature Methanolysis of Polycarbonate (ChemSusChem 2/2025)

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ChemSusChem 2025年第2期18卷

作者： Tzu-Ming Lin Philip Anggo Krisbiantoro Miyu Sato Yu-Chia Chang Eduardo C. Atayde Dr. Weisheng Liao Prof. Yuichi Kamiya Dr. Ryoichi Otomo Prof. Kevin C.-W. Wu Department of Chemical Engineering National Taiwan University Taipei 10617 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei 11529 Taiwan International Graduate Program of Molecular Science and Technology National Taiwan University Taipei 10617 Taiwan Graduate School of Environmental Science Hokkaido University Nishi 5 Kita 10 Kita-ku Sapporo 060-0810 Japan Department of Chemistry National Tsing Hua University Hsinchu 30013 Taiwan Faculty of Environmental Earth Science Hokkaido University Nishi 5 Kita 10 Kita-ku Sapporo Japan Department of Chemical Engineering and Materials Science Yuan Ze University Chung-Li Taoyuan Taiwan Department of Chemical Engineering Chung Yuan Christian University Taoyuan City 320 Taiwan

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When quantum dots meet blue phase liquid crystal elastomers:visualized full-color and mechanically-switchable circularly polarized luminescence

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Light(science & Applications) 2024年第6期13卷 1210-1220页

作者： Shan Li Yuqi Tang Qingyan Fan Ziyuan Li Xinfang Zhang Jingxia Wang Jinbao Guo Quan Li Key Laboratory of Carbon Fibers and Functional Polymers Ministry of Educationand College of Materials Science and EngineeringBeijing University of Chemical Technology100029BeijingChina Institute of Advanced Materials and School of Chemistry and Chemical Engineering Southeast UniversityNanjing211189China Materials Science Graduate Program Kent State UniversityKentOH44242USA CAS Key Laboratory of Bio-Inspired Materials and Interfacial Sciences Technical Institute of Physics and ChemistryChinese Academy of Sciences100190BeijingChina

Polymer-based circularly polarized luminescence(CPL)materials with the advantage of diversified structure,easy fabrication,high thermal stability,and tunable properties have garnered considerable ***,adequate and precise tuning over CPL in polymer-based materials remains challenging due to the difficulty in regulating chiral ***,visualized full-color CPL is achieved by doping red,green,and blue quantum dots(QDs)into reconfigurable blue phase liquid crystal elastomers(BPLCEs).In contrast to the CPL signal observed in cholesteric liquid crystal elastomers(CLCEs),the chiral 3D cubic superstructure of BPLCEs induces an opposite CPL ***,this effect is entirely independent of photonic bandgaps(PBGs)and results in a high glum value,even without matching between PBGs and the emission bands of ***,the lattice structure of the BPLCEs can be reversibly switched via mechanical stretching force,inducing on-off switching of the CPL signals,and these variations can be further fixed using dynamic disulfide bonds in the ***,the smart polymer-based CPL systems using the BPLCEs for anti-counterfeiting and information encryption have been demonstrated,suggesting the great potential of the BPLCEs-based CPL active materials.

关键词： circular quantum crystal

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Reuse of sodium–doped iridium oxide nanoparticles as a bio–stimulating electrode by a chemical and electrochemical recovery process

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Ceramics International 2024年第4期50卷 6220-6228页

作者： Tso, Kuang-Chih Chen, Chieh-Hsuan Chen, Po-Chun Li, Shao-Sian Chen, Jeng-Lung Ohta, Jun Wu, Pu-Wei Division of Materials Science Graduate School of Science and Technology Nara Institute of Science and Technology Nara630-0192 Japan Graduate Degree Program of Science and Technology of Accelerator Light Source National Yang Ming Chiao Tung University Hsinchu300 Taiwan Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu300 Taiwan Institute of Materials Science and Engineering National Taipei University of Technology Taipei106 Taiwan National Synchrotron Radiation Research Center Hsinchu300 Taiwan

A sequential chlorination and electrochemical reduction process is demonstrated to convert Na–doped iridium oxide nanoparticles into useful IrIIICl63−(aq) serving as the precursor for the fabrication of bio–stimulating electrode. The Na–doped iridium oxide nanoparticles are treated in 35 wt% hydrochloric acid at 70 °C for 18 h to form IrIVCl62−(aq) with pH of 0.3, so the latter could be readily reduced to IrIIICl63−(aq) at a potentiostatic mode of 0.6 V (vs. SCE). The oxidation state and the nature of complexing ligands for the regenerated IrIIICl63− and IrIVCl62−, as well as commercially available IrIIICl63− are validated by X–ray Absorption Spectroscopy. UV–Vis profiles of regenerated IrIVCl62−(aq) are recorded and the absorbance at 487 nm signal is benchmarked against that of standard IrIVCl62−(aq) to obtain the effective regeneration ratio of 68.6%. X–ray diffraction patterns of Na–doped iridium oxide nanoparticles before and after the annealing treatment indicate the amorphous structure facilitates the chlorination step. The regenerated IrIIICl63− is reused to synthesize Na–doped iridium oxide thin film serving as a bio–stimulating electrode for implantable bio–electronics. The regenerated Na–doped iridium oxide thin film reveals a charge-storage capacity of 0.32 mC/cm2-nm and impressive stability that are comparable to those of fresh Na–doped iridium oxide thin film derived from commercially available IrIIICl63−. © 2023 Elsevier Ltd and Techna Group S.r.l.

关键词： Transition metal oxides

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Two-dimensional multi-array formation of hepatocyte spheroids on a micro-fabricated PEG-brush surface

Two-dimensional multi-array formation of hepatocyte spheroid...

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Transactions - 7th World biomaterials Congress

作者： Otsuka, H. Satomi, T. Itadani-Harada, J. Nagasaki, Y. Horiike, Y. Kataoka, K. Biomaterials Center Natl. Inst. for Materials Science Tsukuba Ibaraki Japan Department of Materials Science Tokyo University of Science Noda Chiba Japan Dept. of Mat. Sci. and Engineering Graduate School of Engineering University of Tokyo Tokyo Japan

ISBN: (纸本)1877040193

The micropatterning of rat primary hepatocyte hetero-spheroids was prepared on microfabricated glass substrates coated with poly(ethylene glycol) (PEG) brushes. Co-cultivation of hepatocytes and endothelial cells was used to stabilize hepatocyte viability and liver-specific functions. Rat primary hepatocytes, suspended in a culture medium, were applied to the patterned dishes with cultured endothelial cells selectively located in the circular domains. Rat primary hepatocytes formed spheroids within 24-h only on the circular regions of existing endothelial cells, generating a two-dimensional (2D)-arrayed structure of the hepatocyte spheroids.

关键词： Cells

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Construction of micro-patterned poly (ethylene glycol) brush surface for controlling protein and cell interactions

Construction of micro-patterned poly (ethylene glycol) brush...

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Transactions - 7th World biomaterials Congress

作者： Satomi, T. Otsuka, H. Nagasaki, Y. Horiike, Y. Kataoka, K. Biomaterials Center Natl. Inst. for Materials Science Tsukuba Ibaraki Japan Department of Materials Science Tokyo University of Science Noda Chiba Japan Dept. of Mat. Sci. and Engineering Graduate School of Engineering University of Tokyo Tokyo Japan

ISBN: (纸本)1877040193

The micro-patterned poly(ethylene glycol) (PEG) brush surface for controlling protein and cell interactions was constructed. PEGylated substrates with two-dimensional arrays of plasma-etched circular domains were prepared by coating of mercapto-functionalized (PEG) on Au surface, followed by plasma-etching through a metal mask pattern with circular holes. The micro-patterning of bovine articular chondrocytes or rat primary hepatocytes hetero-spheroids underlaid with human umbilical endothelial cells (HUVEC) was achieved. These arrayed spheroids are promising materials for tissue and cell-based biosensors (TBB and CBB) as well as tissue engineering technologies.

关键词： Polyethylene glycols

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Low-Temperature Methanolysis of Polycarbonate over Solid Base Sodium Aluminate

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Langmuir 2024年第10期40卷 5338-5347页

作者： Krisbiantoro, Philip Anggo Sato, Miyu Lin, Tzu-Ming Chang, Yu-Chia Peng, Tzu-Yun Wu, Yun-Chih Liao, Weisheng Kamiya, Yuichi Otomo, Ryoichi Wu, Kevin C.-W. Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei11529 Taiwan International Graduate Program of Molecular Science and Technology National Taiwan University Taipei10617 Taiwan Department of Chemical Engineering College of Engineering National Taiwan University Taipei10617 Taiwan Graduate School of Environmental Science Hokkaido University Nishi 5 Kita 10 Sapporo060-0810 Japan Faculty of Environmental Earth Science Hokkaido University Nishi 5 Kita 10 Sapporo060-0810 Japan Center of Atomic Initiative for New Materials National Taiwan University Taipei10617 Taiwan Department of Chemical Engineering and Materials Science Yuan Ze University Taoyuan320 Taiwan

Herein, a low-cost and readily available sodium aluminate (NaAlO2) was used as a solid base catalyst for the depolymerization of polycarbonate (PC) via methanolysis in the presence of tetrahydrofuran (THF) as a solvent. NaAlO2 was highly active for the reaction, and the performance was comparable to that of soluble strong base SrO and much higher than those of MgO and CaO. By the reaction over the catalyst, a highly pure and crystalline bisphenol A (BPA) was obtained. Among tested organic solvents, THF was the best in aiding PC methanolysis over NaAlO2 due to the polarity similar to PC according to Hansen solubility parameters (HSPs). At 60 °C, 98.1% PC conversion and 96.8% BPA yield were achieved within just 2 h. NaAlO2 was reusable without any severe catalyst deactivation in at least four runs. The mechanistic study revealed that the reaction proceeded via the methoxide pathway, with THF aiding the dissolution of PC. The reaction over NaAlO2 possessed a low apparent activation energy (Ea) of 75.1 kJ mol-1, which is the lowest ever reported so far for the reaction over solid catalysts. © 2024 The Authors. Published by American Chemical Society.

关键词： Sodium Aluminate

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Bioplastics from orange processing waste and poly(lactic acid)

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Future Foods 2025年 11卷

作者： Laís T. Possari Marina S. de Paula George F. Nunes Iago A. Reis Marcos V. Basaglia Caio G. Otoni Sílvia H.P. Bettini Federal University of São Carlos (UFSCar) Graduate Program in Materials Science and Engineering (PPGCEM) São Carlos SP 13565-905 Brazil Federal University of São Carlos (UFSCar) Department of Materials Engineering (DEMa) São Carlos SP 13565-905 Brazil University of Campinas (UNICAMP) Institute of Chemistry Campinas SP 13083-862 Brazil

Bioplastics have the potential to mitigate the aggravating crisis of plastic pollution. Valorizing agri-food side streams for such a purpose is particularly beneficial as it valorizes massively produced waste, thus contributing to the shift towards circular and regenerative productive chains. In this work, citrus pulp (CP) obtained as a by-product from orange juice production was upcycled into thermoplastic compounds via extrusion-assisted plasticization with glycerol. Compounds with poly(lactic acid) (PLA) were then produced by extrusion melt blending. An experimental 2² factorial design with a central point was performed to evaluate their mechanical, thermal, and biodegradation behavior. The levels for the variables plasticized CP (PCP) and glycerol contents were 30 and 70 % for PCP, and 40 and 60 % for glycerol. Calorimetry showed that PCP increased PLA free volume and chain mobility. Still, the different fractions of PCP and glycerol did not alter the melting behavior of the compounds significantly. PCP led to a progressive toughening effect on PLA. Mass loss after 90 d of soil burial reached 53–64 % for the formulations containing 70 % PCP, and PLA chain scission was accelerated at 30 % PCP with 60 % glycerol, and 70 % PCP with 40 % glycerol. This work opens new pathways to citrus biomass valorization by exploring CP, a scarcely investigated residue, and a novel processing strategy. The produced compounds can be applied as bio-based semi-rigid packaging and utensils.

关键词： Biodegradable plastic PLA Biomass Food waste Upcycling Citrus sinensis

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