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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL J.choi s.F.sHAH C.LEE s.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles.w.th poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)

Inclusive quasielastic neutrino-nucleus scattering with energy density functional nuclear models

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Chinese Physics C 2024年第8期48卷 153-158页

作者： K.s.Kim soonchul choi Hana Gil Chang Ho Hyun school of liberal arts and science korea aerospace universitygoyang 10540korea Center for exotic nuclear studies institute for basic sciencedaejeon 34126korea Center for extreme nuclear matters korea universityseoul 02841korea Department of physics education daegu universitygyeongsan 38453korea

In this study,we calculated the inclusive charged-current neutrino-nucleus scattering from ^(40)Ar in the quasielastic *** explore the effect of uncertainties stemming from the nuclear structure,we used the KIDs(Korea-IBs-Daegu-sKKU)nuclear energy density functional and skyrme force models,namely sLy4,skI3,and *** models.w.re selected to have distinct behavior in terms of the density dependence of the symmetry energy and the effective mass of the *** the charged-current neutrino scattering,the single-and double-differential cross sections.w.re calculated for various *** cross sections are reported as a function of the incident neutrino *** theoretical cross sections.w.re compared with experimental data,and the roles of the effective mass and symmetry energy were investigated in terms of charged-current neutrino-nucleus scattering.

关键词： energy density functional neutrino-nucleus scattering symmetry energy effective mass of the nucleon

Extracellular vesicles and angiotensin-converting enzyme 2 in COVID-19 disease

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BIOCELL 2024年第1期48卷 1-8页

作者： YU LIU ROBERT J.KAsPER NATALIE J.s.choi Department of Family and Community Medicine Northwestern University Feinberg School of MedicineChicagoIllinois

Extracellular vesicles(EVs)are membranous vesicular structures released from almost all eukaryotic cell types under different physiological or pathological *** evidence demonstrates that EVs can serve as mediators of intercellular communication between donor and recipient cells or microorganism-infected and noninfected *** disease 2019(COVID-19)disease is caused by infection of the severe acute respiratory syndrome coronavirus 2(sARs-CoV-2)of host cells in the respiratory system and various extra-pulmonary tissue/organs,resulting in complications of multiple organ *** the cell surface receptor,angiotensin-converting enzyme 2(ACE2)mediates cellular entry of sARs-CoV-2 into the host cells in patients.w.th *** studies have found that ACE2 can be released with EVs.w.ich have been shown to interfere with the entry of the virus into host cells and thus may be involved in COVID-19 *** addition,ACE2,neprilysin(NEP),and thimet oligopeptidase(TOP)are the key enzymes that regulate angiotensin metabolism by converting angiotensin II or angiotensin I to angiotensin 1-7,the latter of which has protective effects in counterbalancing the harmful effects of angiotensin II in COVID-19 *** review summarizes the recent research progress regarding EV-associated ACE2,NEP,and TOP and the perspectives of their potential involvement in the pathophysiology of COVID-19 disease.

关键词： Extracellular vesicles COVID-19 Angiotensin converting enzyme 2 Thimet oligopeptidase

Modeling asymmetric fracture mechanics of Mg alloy wire in drawing process

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Journal of Magnesium and Alloys 2024年第5期12卷 2057-2069页

作者： sunghoon choi Jongwon shin Joung sik suh Dongchoul Kim Department of Mechanical Engineering Sogang UniversitySeoul04107Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

In this study,a numerical analysis.w.s conducted on the ductile fracture of a 2-mm diameter Mg-1Zn-0.5Mn-0.5sr-0.1Ca alloy wire during *** hexagonally close-packed crystal structure of Mg alloys causes asymmetric fracture behavior,especially in the compression *** aim of this study is to develop a comprehensive damage model for Mg alloy wire that accurately predicts ductile fracture,with a focus on the compression region.A novel experimental method was introduced to measure the ductile fracture of Mg alloy wires under different stress *** wire drawing process.w.s simulated using the Generalized Incremental stress-state dependent damage(GIssMO)Model and the semi-Analytical Model for Polymers(sAMP)*** damage model's prediction and the experimental results.w.re found to be in excellent agreement,especially in determining crack *** analysis established a safe zone diagram for die angle and reduction ratio,and experimental validation confirmed the feasibility of this *** proposed damage model can provide a practical and reliable analysis for optimizing the drawing process of Mg alloy wire.

关键词： Mg alloy wire drawing Finite element method Damage model safe zone diagram

Effects of low molecular weight polysaccharide from sargassum thunbergii against palmitic acid-induced intracellular lipid accumulation in 3T3-L1 adipocyte and HepG2 cells

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Food science and Human wellness 2024年第4期13卷 2244-2252页

作者： Hyo-Geun Lee D.P.Nagahawatta M.J.M.s.Kurera Kyung-Mo song Yun-sang choi You-Jin Jeon Min-Cheol Kang Department of Marine Life sciences Jeju National UniversityJeju 63243Republic of Korea Department of Biotechnology Faculty of Agriculture and Plantation ManagementWayamba University of Sri LankaMakanduraGonawila(NWP)60170Sri Lanka Research Group of Food Processing Korea Food Research Institute245Wanju 55365Republic of Korea

Low molecular weight polysaccharides can be isolated from sargassum thunbergii(LMPsT)and in vitro experiments.w.re conducted to evaluate the inhibitory effects on *** natures of LMPsT were attained from *** and appraised their LMPsT on palmitic acid(PA)induced lipid accretion in Hep G2,and 3T3-L1 *** treatment lessened lipid deposition and intracellular free fatty acid and triglyceride intensities in PA-treated above mentioned *** mechanistic study publicized that LMPsT2 significantly suppressed adipogenesis and stimulated the PA-treated 3T3-L1 cells occupied in the lipolysis ***,in PA-treated Hep G2 cells,the free fatty acid oxidation was significantly increased by *** these constructive properties of LMPsT2 from ***,is a potential candidate for diminishing the intracellular lipids,and for a therapeutic agent in those conditions.

关键词： sargassum thunbergii Low molecular weight polysaccharide Lipid accumulation Obesity Liver steatosis

The Association between Fear of COVID-19,Obsession with COVID-19,and Post Traumatic stress Disorder in Korean Emergency Rescue Firefighters:A Cross-sectional study

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International Journal of Mental Health Promotion 2024年第6期26卷 475-480页

作者： Yun-Jung choi Heewon song Red Cross College of Nursing Chung-Ang UniversitySeoulSouth Korea Department of Nursing Chung-Ang UniversitySeoulSouth Korea

During the rapid spread of COVID-19,first responders are at risk of being exposed to COVID-19 due to their role in providing first aid and responding to an unspecified number of *** uncertainty can have adverse mental health effects,such as increased anxiety and *** study aimed to investigate the degree of association between fear of COVID-19,obsession with COVID-19,and post-traumatic stress disorder(PTsD)in emergency rescue *** participants.w.re 150 emergency rescue firefighters.w.rking in Region s,*** filled out self-report questionnaires:The data obtained through the Fear of COVID-19 scale,Obsession with COVID-19 scale,and Impact of Event scale-Revised Korean version were subjected to nonparametric statistical analysis using sPss.w.N *** study found a significant correlation between emergency rescue firefighters’fear of COVID-19,obsession with COVID-19,and *** and obsession with COVID-19 were higher among first responder firefighters.w.o were directly involved in COVID-19-related ***,a one-point increase in obsession was associated with a 2.837-point increase in *** on the results.w. found that there is a need for effective control of obsessions and fears among first responder firefighters during COVID-19,and we suggest that there is a need for mental health care for first responder firefighters during the pandemic through the development and support of programs to prevent and mitigate obsessions.

关键词： COVID-19 emergency rescue firefighters fear of COVID-19 mental health promotion obsession with COVID-19 PTsD

The Cause of Institutionalized Private Tutoring in Korea:Defective Public schooling or a Universal Desire for Family Reproduction?

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ECNU Review of Education 2024年第1期7卷 12-41页

作者： sang Hoon Bae Kee Ho choi sungkyunkwan University seoul National University

Purpose:In Korea,private tutoring is considered a social evil that damages the capacity of public schooling and undermines social *** the government has implemented various policies to reduce private tutoring,ranging from improving the quality of education to providing"quasi-private tutoring"programs and regulating the shadow education market,total spending on private tutoring has continued to *** study examines a little noticed but important cause of institutionalized private tutoring in ***/Approach/Methods:The study employed a socio-ecological perspective to analyze both education and socio-structural *** extensive review of the government's private tutoring reduction policies and related literature was ***:Private tutoring functions as a means by which parents can help their children compete for admission to prestigious universities and pass on wealth and social status to their *** in private tutoring has become a social norm that is taken for *** root causes of institutionalized private tutoring lie in both educational and socio-structural ***/Nalue:The study suggests that government policies.w.en ignoring the long-established"grammar"of parents about children's education,may either end in failure or produce unintended consequences.

关键词： Private tutoring social reproduction unintended consequences upward mobility

TEAM:Transformer Encoder Attention Module for Video Classification

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Computer systems science & Engineering 2024年第2期48卷 451-477页

作者： Hae sung Park Yong suk choi Department of Artificial Intelligence Hanyang UniversitySeoulKorea Department of Computer science Hanyang UniversitySeoulKorea

Much like humans focus solely on object movement to understand actions,directing a deep learning model’s attention to the core contexts.w.thin videos is crucial for improving video *** the recent study,Video Masked Auto-Encoder(VideoMAE)employs a pre-training approach with a high ratio of tube masking and reconstruction,effectively mitigating spatial bias due to temporal redundancy in full video *** steers the model’s focus toward detailed temporal ***,as the VideoMAE still relies on full video frames during the action recognition stage,it may exhibit a progressive shift in attention towards spatial contexts,deteriorating its ability to capture the main spatio-temporal *** address this issue,we propose an attention-directing module named Transformer Encoder Attention Module(TEAM).This proposed module effectively directs the model’s attention to the core characteristics.w.thin each video,inherently mitigating spatial *** TEAM first figures out the core features among the overall extracted features from each *** that,it discerns the specific parts of the video where those features are located,encouraging the model to focus more on these informative ***,during the action recognition stage,the proposed TEAM effectively shifts the VideoMAE’s attention from spatial contexts towards the core spatio-temporal *** attention-shift manner alleviates the spatial bias in the model and simultaneously enhances its ability to capture precise video *** conduct extensive experiments to explore the optimal configuration that enables the TEAM to fulfill its intended design purpose and facilitates its seamless integration with the VideoMAE *** integrated model,i.e.,VideoMAE+TEAM,outperforms the existing VideoMAE by a significant margin on something-something-V2(71.3%vs.70.3%).Moreover,the qualitative comparisons demonstrate that the TEAM encourages the model to disregard insignificant featur

关键词： Video classification action recognition vision transformer masked auto-encoder

Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications

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Nano-Micro Letters 2024年第3期16卷 1-35页

作者： sourav Dutta seungmin Noh Roger sanchis Gual Xiangzhong Chen salvador Pané Bradley J.Nelson Hongsoo choi Department of Robotics and Mechatronics Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea DGIsT‑ETH Microrobotics Research Center DGISTDaegu 42988Republic of Korea Multi‑scale Robotics Lab Institute of Robotics and Intelligent SystemsETH Zurich8092 ZurichSwitzerland Institute of Optoelectronics State Key Laboratory of Photovoltaic Science and TechnologyShanghai Frontiers Science Research Base of Intelligent Optoelectronics and PerceptionFudan UniversityShanghai 200433People’s Republic of China

synthetic micromotor has gained substantial attention in biomedicine and environmental ***-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fuel-free propulsion,favorable biocompatibility,and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media,efficient cargo delivery and favorable biocompatibility.A noteworthy number of degradable metal-based micromotors employ bubble propulsion,utilizing water as fuel to generate hydrogen *** novel feature has projected degradable metallic micromotors for active in vivo drug delivery *** addition,understanding the degradation mechanism of these micromotors is also a key parameter for their design and *** propulsion efficiency and life span govern the overall performance of a degradable metallic *** we review the design and recent advancements of metallic degradable ***,we describe the controlled degradation,efficient in vivo drug delivery,and built-in acid neutralization capabilities of degradable micromotors.w.th versatile biomedical ***,we discuss micromotors’efficacy in detecting and destroying environmental ***,we address the limitations and future research directions of degradable metallic micromotors.

关键词： Magnesium Zinc Iron Biodegradable microrobot Biomedical Environmental

Pulsed laser interference patterning of transition-metal carbides for stable alkaline water electrolysis kinetics

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Carbon Energy 2024年第5期6卷 65-80页

作者： Yewon Oh Jayaraman Theerthagiri Ahreum Min Cheol Joo Moon Yiseul Yu Myong Yong choi Department of Chemistry(BK21 FOUR) Research Institute of Natural SciencesGyeongsang National UniversityJinjuRepublic of Korea Core−Facility Center for Photochemistry and Nanomaterials Gyeongsang National UniversityJinjuRepublic of Korea

we investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed laser ablation of Co,Fe,Ti,and Mo metals in *** interaction between carbon s-p-orbitals and metal d-orbitals causes a redistribution of valence structure through charge transfer,leading to the formation of surface defects as observed by X-ray photoelectron *** defects influence the evolved TMCs,making them effective for hydrogen and oxygen evolution reactions(HER and OER)in an alkaline ***_(3)C with more oxygen affinity promoted CoO(OH)intermediates,and the electrochemical surface oxidation to Co_(3)O_(4)was captured via in situ/operando electrochemical Raman probes,increasing the number of active sites for OER *** with more d-vacancies exhibits strong hydrogen binding,promoting HER kinetics.w.ereas Fe_(3)C and TiC with more defect states to trap charge carriers may hinder both OER and HER *** results show that the assembled membrane-less electrolyzer with Co_(3)C∥Co_(3)C and MoC∥MoC electrodes requires~2.01 and 1.99 V,respectively,to deliver a 10 mA cm−2 with excellent electrochemical and structural *** addition,the ascertained pulsed laser synthesis mechanism and unit-cell packing relations.w.ll open up sustainable pathways for obtaining highly stable electrocatalysts for electrolyzers.

关键词： acetone H_(2)and O_(2)evolution reactions pulsed laser ablation surface defects transition-metal carbides water electrolyzer