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Development of an active-site titrant for SARS-CoV-2 main protease as an indispensable tool for evaluating enzyme kinetics

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Acta Pharmaceutica Sinica B 2024年第5期14卷 2349-2357页

作者： Rabea Voget Julian Breidenbach Tobias Claff Alexandra Hingst Katharina Sylvester Christian Steinebach Lan Phuong Vu Renato H.Weiße Ulrike Bartz Norbert Sträter Christa E.Müller Michael Gütschow Pharmaceutical Institute Pharmaceutical&Medicinal ChemistryUniversity of BonnBonn 53121Germany Institute of Bioanalytical Chemistry Center for Biotechnology and BiomedicineLeipzig UniversityLeipzig 04103Germany Department of Natural Sciences University of Applied Sciences Bonn-Rhein-SiegRheinbach 53359Germany

A titrant for the SARS-CoV-2 main protease(M^(pro))was developed that enables,for the first time,the exact determination of the concentration of the enzymatically active M^(pro) by active-site *** covalent binding mode of the tetrapeptidic titrant was elucidated by the determination of the crystal structure of the enzyme–titrant *** fluorogenic substrates of M^(pro),including a prototypical,internally quenched Dabcyl-EDANS peptide,were compared in terms of solubility under typical assay *** exploiting the new titrant,key kinetic parameters for the M^(pro)-catalyzed cleavage of these substrates were determined.

关键词： COVID-19 SARS-CoV-2 Main protease Peptide nitriles Fluorogenic substrates Active-site titration X-ray crystallography Inner filter effect

EXISTENCE OF A NONTRIVIAL SOLUTION FOR CHOQUARD'S EQUATION

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Acta Mathematica Scientia 2006年第3期26卷 460-468页

作者：张正杰 Tassilo Küpper 胡爱莲夏红强 Laboratory of Nonlinear Analysis Department of Mathematics Central China Normal UniversityWuhan 430079China Mathematisches der Universit(a|¨)t zu K(o|¨)ln D-50923 K(o|¨)ln Germany Department of Mathematics Central China Normal University Wuhan 430079China Department of Mathematics University of Manchester Oxford RoadManchester M13 9PLUK

In this article, the authors consider the existence of a nontrivial solution for the following equation： -△u＋u=q（x）（｜u｜^2＊1/｜x｜）u, x∈R^3, where q（x） satisfies some conditions. Using a Min-Max method, th... 详细信息

关键词： Existence Choquard's equation Min-Max

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Dynamic in situ reconstruction of NiSe2 promoted by interfacial Ce2（CO3）2O for enhanced water oxidation

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Journal of Energy Chemistry 2024年第11期 472-480页

作者： Fengli Wei Jinghao Shen Jiayin Xie Zuyang Luo Luyan Shi Tayirjan Taylor Isimjan Xiulin Yang Jieshan Qiu Bin Wu Guangxi Key Laboratory of Low Carbon Energy Materials School of Chemistry and Pharmaceutical Sciences Guangxi Normal University Saudi Arabia Basic Industries Corporation (SABIC) at King Abdullah University of Science and Technology (KAUST) State Key Laboratory of Chemical Resource Engineering State Key Laboratory of Organic-Inorganic Composites College of Chemical Engineering Beijing University of Chemical Technology Helmholtz-Zentrum Berlin für Materialien und Energie GmbH Institute of Physics Humboldt University Berlin

Understanding and manipulating the structural evolution of water oxidation electrocatalysts lays the foundation to finetune their catalytic ***,we present a synthesis of NiSe2-Ce2（CO3）2O heterostructure and demonstrate the efficacy of interfacial Ce2（CO3）2O in promoting the formation of catalytically active centers to improve oxygen evolution ***-situ Raman spectroscopy shows that incorporation of Ce2（CO3）2O into NiSe2causes a cathodic shift of the Ni2+→Ni3+transition *** electrochemical impedance spectroscopy reveals that strong electronic coupling at heterogeneous interface accelerates charge transfer ***,density functional theory calculations suggest that actual catalytic active species of NiOOH transformed from NiSe2,which is coupled with Ce2（CO3）2O,can optimize electronic structure and decrease the free energy barriers toward fast oxygen evolution reaction（OER） ***,the resultant NiSe2-Ce2（CO3）2O electrode exhibits remarkable electrocatalytic performance with low overpotentials(268/304 mV@50/100 mA cm-2) and excellent stability(50 mA cm-2for 120 h) in the alkaline *** work emphasizes the significance of modulating the dynamic changes in developing efficient electrocatalyst.

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Correcting Climate Model Sea Surface Temperature Simulations with Generative Adversarial Networks:Climatology,Interannual Variability,and Extremes

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Advances in Atmospheric Sciences 2024年第7期41卷 1299-1312页

作者： Ya WANG Gang HUANG Baoxiang PAN Pengfei LIN Niklas BOERS Weichen TAO Yutong CHEN BO LIU Haijie LI State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Earth System Modelling School of Engineering and DesignTechnical University of MunichOttobrunn 85521Germany Potsdam Institute for Climate Impact Research Potsdam 14412Germany Department of Mathematics and Global Systems Institute University of ExeterExeter EX44QEUK CMA Earth System Modeling and Prediction Centre(CEMC) Chinese Academy of Meteorological SciencesBeijing 100081China

Climate models are vital for understanding and projecting global climate change and its associated ***,these models suffer from biases that limit their accuracy in historical simulations and the trustworthiness of future *** these challenges requires addressing internal variability,hindering the direct alignment between model simulations and observations,and thwarting conventional supervised learning ***,we employ an unsupervised Cycle-consistent Generative Adversarial Network(CycleGAN),to correct daily Sea Surface Temperature(SST)simulations from the Community Earth System Model 2(CESM2).Our results reveal that the CycleGAN not only corrects climatological biases but also improves the simulation of major dynamic modes including the El Niño-Southern Oscillation(ENSO)and the Indian Ocean Dipole mode,as well as SST ***,it substantially corrects climatological SST biases,decreasing the globally averaged Root-Mean-Square Error(RMSE)by 58%.Intriguingly,the CycleGAN effectively addresses the well-known excessive westward bias in ENSO SST anomalies,a common issue in climate models that traditional methods,like quantile mapping,struggle to ***,it substantially improves the simulation of SST extremes,raising the pattern correlation coefficient(PCC)from 0.56 to 0.88 and lowering the RMSE from 0.5 to *** enhancement is attributed to better representations of interannual,intraseasonal,and synoptic scales *** study offers a novel approach to correct global SST simulations and underscores its effectiveness across different time scales and primary dynamical modes.

关键词： generative adversarial networks model bias deep learning El Niño-Southern Oscillation marine heatwaves

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Equilibrium Segregation to Free Surface:Kinet ics and Experiment

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Chinese Physics Letters 1999年第5期16卷 364-366页

作者： CAO Ze-xian Ralf Mueller WANG En-ge NIE Yu-xin State Key Laboratory for Surface Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080 Department of Physics University Kaiserslautern67653 KaiserslauternGermany

Fick's first law is modified with an additional term df(x)/dx to describe the segregation phenomenon,f(x)is a local,analytical function related to the depth profile at *** thus can be determined experimentally by depth profiling *** starting in an initially homogeneous solid is described by an inhomogeneous diffusion equation on the half-infinite *** with and without formation of overlayer suggests different boundary *** solution for the Ansatz f(x)=as exp(-x/d_(s))is in perfect agreement with experimental results on sulphur segregation to the surface of *** from the detailed kinetics,activation energy can be inferred from the surface concentration evolution under different *** sulphur segregation in titanium,E_(act)=718 meV/atom.

关键词： technique. titanium sulphur

Female mating competition alters female mating preferences in common gobies

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Current Zoology 2018年第3期64卷 351-361页

作者： Katja HEUBEL Institute for Zoology Ecological Research Station Rees Grietherbusch 3a D-46459 Rees Germany Tvarminne Zoological Station University of Helsinki J.A. Palmenin tie 260 10900 Hanko Finland

Mating decisions can be affected by intrasexual competition and sensitive to operational sex-ratio （OSR） changes in the population. Conceptually, it is assumed that both male and female matecompetition may interfere with female reproductive decisions. Experimentally, however, the focus has been on the effect of male competition on mate choice. In many species with paternal care as in the common goby Pomatoschistus microps, the OSR is often female-biased and female matecompetition for access to available nesting males occurs. Using the same protocol for 3 experi- ments testing the effect of a perceived risk of female mate-competition, I studied female preferences for nest-holding males differing in its nest size （large/small）, body size （large/small）, and nest status （with/without eggs already in nest） and measured mating decisions, spawning latencies, and clutch size. Regardless of the social context, females preferred males with larger nests. A preference for large males was only expressed in presence of additional females. For nest status, there was a tendency for females to prefer mating with males with an empty nest. Here, female-female competition increased the propensity to mate. The results of this study show that females are sensitive to a female competitive social environment and suggest that in choice situations, females respond to the social context mainly by mating decisions per se rather than by adjusting the clutch size or spawning latency. Females base their mating decisions not only on a male＇s nest size but also on male size as an additional cue of mate quality in the presence of additional females.

关键词： audience effect intrasexual competition mate sampling parental care Pomatoschistus microps sex-roles size.

Relationships between soil seed banks and above-ground vegetation along a disturbance gradient in the W National Park trans-boundary biosphere reserve,West Africa

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Journal of Plant Ecology 2017年第2期10卷 349-363页

作者： Patrice Savadogo Lassina Sanou SDjibril Dayamba Fidele Bognounou Adjima Thiombiano World Agroforestry Centre and International Crop Research Institute for the Semi-Arid Tropics(ICRAF-ICRISAT) West and Central Africa Region-Sahel NodeBP 12404 NiameyNiger Centre National de la Recherche Scientifique et Technologique INERADépartement Productions Forestières03 BP 7047Ouagadougou 03BurkinaFaso Unitéde Formation et de Recherche en Sciences de la Vie et de la Terre/Laboratoire de Biologie et Ecologie Végétales(UFR/SVT) Universitéde Ouagadougou03 BP 7047Ouagadougou 03BurkinaFaso World Agroforestry Centre(ICRAF) West and Central Africa Regional Office-Sahel NodeBP E5118 BamakoMali Département des Sciences Biologiques Université´du QuébecàMontréal2080 rue Saint Urbain8888Montréal QC H3C 3P8Canada

Aims Vegetation succession depends on the availability of suitable prop-agules in the soils,thus knowledge of soil seed banks is essential for formulating effective strategies for restoring the vegetation of degraded *** W National Park,the only trans-boundary bio-sphere reserve in West Africa,is being extensively fragmented and degraded in recent *** aims of this study were to assess the reserve’s soil seed banks,their relationships with standing veg-etation and bundle of disturbances and their potential significance for vegetation *** The size and composition of the above-ground species vegetation were assessed in nine plots of 1 ha each representing a range of habitats with differing disturbance severity(low,intermediate and high).A total of 702 soil samples were taken from three layers(0-3,3-6 and 6-9 cm)and soil seed bank was analyzed using the seed-ling emergence *** Findings Generally,seeds of non-woody taxa dominated in samples from all soil depths and habitats of all disturbance *** mean soil seed density was 17.8,24.4 and 26.3 seeds/dm^(3) in samples from the least,intermediate and most disturbed sites,respectively,and highest in the upper soil layers in all *** results indi-cate that there is limited potential for restoring woody vegetation solely from soil seed banks,and that woody species in the region rely more on recently shed seeds trapped in the standing dead biomass and litter on the ground than soil seed banks for ***,human intervention is needed to accelerate forest recovery,mainly through alleviating anthropogenic impacts on the ecosystem(for instance,avoiding destruction of new seeds by intense fire),and site manipulation to improve environmen-tal conditions for seedling establishment and *** ways of restoring forests than through the soil seed bank(*** seeds collected elsewhere,and planting tree seedlings)could also be relevant.

关键词： disturbance savanna-woodland restoration regeneration seed bank vegetation degradation West Africa

Lattice Distortion Analysis Directly from High Resolution Transmission Electron Microscopy Images —the LADIA Program Package

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Journal of Materials Science & Technology 2002年第2期18卷 135-138页

作者： Y.Rau, N.Y.Jin-Phillipp and F.PhillippMax-Planck-Institut fiir Metallforschung, Heisenbergstrasse 1, Stuttgart, D-70569, Germany [ Manuscript received November 22, 2001] Max-Planck-Inst. für Metall. Heisenbergstrasse 1 D-70569 Stuttgart Germany

Direct strain mapping from high resolution transmission electron microscopy images is possible for coherent structures. At proper imaging conditions the intensity peaks in the image have a constant spatial relationship with the projected atom columns. This allows the determination of the geometry of the projected unit cell without comparison with image simulations. The fast procedure is particularly suited for the analysis of large areas. The software package LADIA is written in the PV-WAVE code and provides all necessary tools for image processing and analysis. Image intensity peaks are determined by a cross-correlation technique, which avoids problems from noise in the low spatial frequency range. The lower limit of strain that can be detected at a sampling rate of 44 pixels/nm is≈2%.

关键词： High-resolution transmission electron microscopy Distortion analysis

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Oxidization-induced structural optimization of Ni_(3)Fe-N-C derived from 3D covalent organic framework for high-efficiency and durable oxygen evolution reaction

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Nano Research 2023年第5期16卷 6710-6720页

作者： Haibing Meng Bin Wu Tianxiao Sun Long Wei Yunlong Zhang Bo Liu Kai Chen Zhen-Bo Wang Shuhui Sun Chunru Wang Xian-Ming Zhang College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China Helmholtz-Zentrum Berlin für Materialien und Energie GmbH Albert-Einstein-Straße 15Berlin 12489Germany Institute of Physics Humboldt University BerlinNewton-Straße 15Berlin 12489Germany National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China Institute National de La Recherche Scientifique(INRS)-CentreÉnergie Matériaux Télécommunications VarennesQC J3X 1P7Canada Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Nanostructure and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

NiFe composites have been regarded as promising candidates to replace commercial noble-based electrocatalysts for the oxygen evolution reaction(OER).However,their practical applications still suffer from poor conductivity,limited activity,*** address these issues,herein,by utilizing three-dimensional covalent organic framework(3D-COF)with porous confined structures and abundant coordinate N sites as the precursor,the partially oxidized Ni_(3)Fe nanoalloys wrapped by Ndoped carbon(N-C)layers are constructed via simple pyrolysis and subsequent *** from the 3D curved hierarchical structure,high-conductivity of Ni_(3)Fe and N-C layers,well-distributed active sites,the as-synthesized O-Ni_(3)Fe-NC catalyst demonstrates excellent activity and durability for catalyzing *** and theoretical analyses disclose that both high-temperature oxidization and the OER process greatly promote the formation and exposure of the Ni(Fe)OOH active species as well as lower charge transfer resistance,inducing its optimized OER *** robust graphitized N-C layers with superior conductivity and their couplings with oxidized Ni_(3)Fe nanoalloys are beneficial for stabilizing catalytic centers,thereby imparting O-Ni_(3)Fe-N-C with such outstanding *** work not only provides a rational guidance for enriching and stabilizing high-activity catalytic sites towards OER but also offers more insights into the structural evolution of NiFe-based OER catalysts.

关键词： three-dimensional covalent organic framework(3D-COF) Ni_(3)Fe graphitized N-C layer structure optimization durability