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Discovery and characterization of naturally occurring covalent inhibitors of SARS-CoV-2 M^(pro)from the antiviral herb Ephedra

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Chinese Journal of Natural Medicines 2024年第9期22卷 797-807页

作者： HU Qing ZHANG Yiwen CHEN Pengcheng ZHANG Yani ZHU Guanghao LIU Wei WANG Chaoran ZHENG Shuilian shen Nonger WANG Haonan HUANG ping GE Guangbo Center for Clinical Pharmacy Cancer CenterDepartment of PharmacyZhejiang Provincial People’s Hospital(Affiliated People’s Hospital)Hangzhou Medical CollegeHangzhou 310014China Shanghai Frontiers Science Center of TCM Chemical Biology Institute of Interdisciplinary Integrative Medicine ResearchShanghai University of Traditional Chinese MedicineShanghai 201203China Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine Shanghai 200021China Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023China

The Chinese herb Ephedra(also known as Mahuang)has been extensively utilized for the prevention and treatment of coronavirus-induced diseases,including coronavirus disease 2019(COVID-19).However,the specific anti-SARS-CoV-2 compounds and mechanisms have not been fully *** main protease(M^(pro))of SARS-CoV-2 is a highly conserved enzyme responsible for proteolytic processing during the viral life cycle,making it a critical target for the development of antiviral *** study aimed to identify naturally occurring covalent inhibitors of SARS-CoV-2 M^(pro)from Ephedra and to investigate their covalent binding *** results demonstrated that the non-alkaloid fraction of Ephedra(ENA)exhibited a potent inhibitory effect against the SARS-CoV-2 M^(pro)effect,whereas the alkaloid fraction did ***,the chemical constituents in ENA were identified,and the major constituents'anti-SARS-CoV-2 M^(pro)effects were *** the tested constituents,herbacetin(HE)and gallic acid(GA)were found to inhibit SARS-CoV-2 M^(pro)in a time-and dose-dependent *** combination displayed a significant synergistic effect on this key ***,various techniques,including inhibition kinetic assays,chemoproteomic methods,and molecular dynamics simulations,were employed to further elucidate the synergistic anti-M^(pro)mechanisms of the combination of HE and ***,this study deciphers the naturally occurring covalent inhibitors of SARS-CoV-2 M^(pro)from Ephedra and characterizes their synergistic anti-M^(pro)synergistic effect,providing robust evidence to support the anti-coronavirus efficacy of Ephedra.

关键词： Main protease Ephedra Ephedra non-alkaloid fraction Covalent inhibitors Synergistic effect

On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 127-136页

作者： Rui Chen Shun-Qing shen Department of Physics The University of Hong KongHong Kong 999077China Department of Physics Hubei UniversityWuhan 430062China

In topological insulators,massive surface states resulting from local symmetry breaking were thought to exhibit a half-quantized Hall conductance,obtained from the low-energy effective model in an infinite Brillouin *** a lattice model,the surface band is composed of a combination of surface states and bulk *** massive surface states alone may not be enough to support an exact one-half quantized surface Hall conductance in a finite Brillouin zone and the whole surface band always gives an integer quantized Hall conductance as enforced by the TKNN *** explore this,we investigate the band structures of a lattice model describing the magnetic topological insulator film that supports the axion insulator,Chern insulator,and semi-magnetic topological insulator *** reveal that the gapped and gapless surface bands in the three phases are characterized by an integer-quantized Hall conductance and a half-quantized Hall conductance,*** propose an effective model to describe the three phases and show that the low-energy dispersion of the surface bands inherits from the surface Dirac *** gapped surface band manifests a nearly half-quantized Hall conductance at low energy near the center of Brillouin zone,but is compensated by another nearly half-quantized Hall conductance at high energy near the boundary of Brillouin zone because a single band can only have an integer-quantized Hall *** gapless band hosts a zero Hall conductance at low energy but is compensated by another half-quantized Hall conductance at high energy,and thus the half-quantized Hall conductance can only originate from the gapless ***,we calculate the layer-resolved Hall conductance of the *** conclusion suggests that the individual gapped surface band alone does not support the half-quantized surface Hall effect in a lattice model.

关键词： magnetic topological insulator Dirac equation half-quantized Hall conductance

Thermodynamic property of sandwich cylindrical shell structure with metallic wire mesh:Numerical modeling and experimental analysis

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Chinese Journal of Aeronautics 2024年第1期37卷 138-152页

作者： Xin XUE Guojian shen Juan LIAO Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Fujian Shuikou Power Generation Group Co. LTDFuzhou 350000China

As a new addition to lightweight composite structures,the sandwich cylindrical shell with a metallic wire mesh core has emerged as a promising solution for thermodynamic performance analysis at elevated *** intricate interwoven cellular formations within the metallic wire mesh pose difficulties for thermo-mechanical modeling and property ***,the constitutive models employed to characterize hysteresis phenomena were presented,comprising isotropic elasticity,Bergstrom-Boyce model,Ogden hyper-elasticity,and parameter identification through mechanical examinations at varying ***,the finite element modeling of cylindrical shell structures was determined for modal and steady-state dynamic ***,the experimental procedures were carried out,including the preparation of the sandwich cylindrical shell and the dynamic testing *** first-order natural frequency of the cylindrical shell structure is close to the resonance frequency of the dynamic test results,with a maximum error of 6.5%,demonstrating the accuracy of the simulation *** compared to the solid-core cylindrical shell,the average insertion loss of the sandwich cylindrical shell structure within the frequency range of 10–1000 Hz at room temperature is up to 11.09 ***,at elevated temperatures,the average insertion loss of the sandwich cylindrical shell decreases but fluctuates as the temperature changes.

关键词： Energy dissipation Metallic matrix composites Numerical analysis Sandwich structure Thermodynamic properties

Bioinspired 3D flexible devices and functional systems

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National Science Review 2024年第3期11卷 271-295页

作者： Xu Cheng Zhangming shen Yihui Zhang Applied Mechanics Laboratory Department of Engineering Mechanics Tsinghua University Laboratory of Flexible Electronics Technology Tsinghua University

Flexible devices and functional systems with elaborated three-dimensional(3D) architectures can endow better mechanical/electrical performances, more design freedom, and unique functionalities, when compared to their two-dimensional(2D) counterparts. Such 3D flexible devices/systems are rapidly evolving in three primary directions, including the miniaturization, the increasingly merged physical/artificial intelligence and the enhanced adaptability and capabilities of heterogeneous *** challenges exist in this emerging research area, such as relatively poor controllability in the locomotion of soft robotic systems, mismatch of bioelectronic interfaces, and signal coupling in multi-parameter sensing. By virtue of long-time–optimized materials, structures and processes, natural organisms provide rich sources of inspiration to address these challenges, enabling the design and manufacture of many bioinspired 3D flexible devices/systems. In this Review, we focus on bioinspired 3D flexible devices and functional systems, and summarize their representative design concepts, manufacturing methods, principles of structure-function relationship and broad-ranging applications. Discussions on existing challenges, potential solutions and future opportunities are also provided to usher in further research efforts toward realizing bioinspired 3D flexible devices/systems with precisely programmed shapes,enhanced mechanical/electrical performances, and high-level physical/artificial intelligence.

关键词： bioinspired designs biomimetic 3D structures 3D flexible electronics 3D functional systems direct 3D manufacture 2D-to-3D assembly

Theoretical insights of the pharmaceutical compound fluoxetine in water:Role in direct photolysis and indirect photolysis by free radicals

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Journal of Environmental Sciences 2024年第8期142卷 269-278页

作者： Ying Lu Se Wang Yifan shen School of Environmental Science and Engineering Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologyJiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlNanjing University of Information Science and TechnologyNanjing 210044China

The frequent detection of pharmaceutical compounds in the environment has led to a growing awareness,which may pose a major threat to the aquatic *** this study,photodegradation(direct and indirect photolysis)of two different dissociation states of fluoxetine(FLU)was investigated in water,mainly including the determination of photolytic transition states and products,and the mechanisms of indirect photodegradation with·OH,CO_(3)^(*-)and NO_(3)^(*).The main direct photolysis pathways are defluorination and C–C bond *** addition,the indirect photodegradation of FLU in water is mainly through the reactions with·OH and NO_(3)^(*),and the photodegradation reaction with CO_(3)^(*-)is relatively difficult to occur in the water *** results provide a theoretical basis for understanding the phototransformation process of FLU in the water environment and assessing its potential risk.

关键词： Fluoxetine Photochemical mechanism Direct photolysis Free radical reaction DFT

Exploring Long-Memory Process in the Prediction of Interval-Valued Financial Time Series and Its Application

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Journal of Systems Science & Complexity 2024年第2期37卷 759-775页

作者： shen Tingting TAO Zhifu CHEN Huayou School of Economics Anhui UniversityHefei 230601China Center for Financial and Statistical Research Anhui UniversityHefei 230061China Stony Brook Institute at Anhui University Anhui UniversityHefei 230601China Center for Applied Mathematics Anhui UniversityHefei 230601China

Long-memory process has been widely studied in classical financial time series analysis,which has merely been reported in the field of interval-valued financial time *** aim of this paper is to explore long-memory process in the prediction of interval-valued time series(IvTS).To model the long-memory process,two novel interval-valued time series prediction models named as interval-valued vector autoregressive fractionally integrated moving average(IV-VARFIMA)and ARFIMAX-FIGARCH were *** the developed long-memory pattern,both of the short term and long-term influences contained in IvTS can be *** an application of the proposed models,interval-valued form of WTI crude oil futures price series is *** to current IvTS prediction models,IV-VARFIMA and ARFIMAX-FIGARCH can provide better in-sample and out-of-sample forecasts.

关键词： ARFIMAX-FIGARCH interval-valued time series IV-VARFIMA long-memory process WTI crude oil futures price

Mechanism of microarc oxidation on AZ91D Mg alloy induced byβ-Mg_(17)Al_(12) phase

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 712-724页

作者： Dajun Zhai Xiaoping Li Jun shen College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg *** kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/*** characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic *** was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and *** nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in *** effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge *** MAO coating on Zr-FSP sample had good wettability and corrosion ***,TiO_(2)particles were hardly detected in the coating on TiFSP sample.

关键词： AZ91D Mg alloy microarc oxidation friction stir processing ZrO_(2) TiO_(2) β-Mg_(17)Al_(12)

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黑河中游间作灌溉农田的能量平衡

冰川冻土 2006年第3期28卷 443-449页

作者：吴锦奎丁永建沈永平王根绪中国科学院寒区旱区环境与工程研究所

利用布设在黑河流域中游的张掖绿洲区的一套自动气象观测系统在2004年作物生长期内的完整资料,分析了黑河中游春小麦和玉米间作农田生态系统的辐射收支,在此基础上选用波文比能量平衡法(BREB)进行了能量平衡计算.结果表明:间作作物土壤... 详细信息

利用布设在黑河流域中游的张掖绿洲区的一套自动气象观测系统在2004年作物生长期内的完整资料,分析了黑河中游春小麦和玉米间作农田生态系统的辐射收支,在此基础上选用波文比能量平衡法(BREB)进行了能量平衡计算.结果表明:间作作物土壤系统截获的太阳短波辐射占太阳总辐射的比例从生长初期的0.81持续增加到生长末期的0.86;净辐射在生长初期较小,生长中期第一阶段增幅大,至第二阶段达到最大,生长末期降低;净辐射占太阳总辐射的比例与净辐射的变化相似.能量平衡中,净辐射的消耗以潜热为主,占70%左右,感热能量占20%,土壤热通量占净辐射总值的10%.不同生长阶段的能量平衡差异较大,能量平衡在不同生长阶段呈现出不同的日变化特征.

关键词：辐射收支能量平衡间作黑河中游

H_(∞)/Passive Synchronization of Semi-Markov Jump Neural Networks Subject to Hybrid Attacks via an Activation Function Division Approach

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Journal of Systems Science & Complexity 2024年第3期37卷 1023-1036页

作者： ZHANG Ziwei shen Hao SU Lei School of Electrical and Information Engineering Anhui University of TechnologyMa'anshan 243002China Anhui Province Key Laboratory of Special Heavy Load Robot and School of Electrical and Information Engineering Anhui University of TechnologyMa'anshan243002China

In this work,an H_(∞)/passive-based secure synchronization control problem is investigated for continuous-time semi-Markov neural networks subject to hybrid attacks,in which hybrid attacks are the combinations of denial-of-service attacks and deception attacks,and they are described by two groups of independent Bernoulli *** this foundation,via the Lyapunov stability theory and linear matrix inequality technology,the H_(∞)/passive-based performance criteria for semi-Markov jump neural networks are ***,an activation function division approach for neural networks is adopted to further reduce the conservatism of the ***,a simulation example is provided to verify the validity and feasibility of the proposed method.

关键词： Activation function division approach deception attacks denial-of-service attacks H_(∞)/passive synchronization semi-Markov jump neural networks