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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

Suspect and non-targeted screening of chemical pollutants in Botswana's aquatic environments

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emerging Contaminants 2024年第3期10卷 363-373页

作者： Kgato P.Selwe Charlotte R.head Gothatamang N.Phokedi Jens e.T.Andersen J.Brett Sallach Caroline e.h.Dessent Department of Chemistry University of YorkHeslingtonYorkUnited Kingdom Department of environment and Geography University of YorkHeslingtonYorkUnited Kingdom Department of Biology University of YorkHeslingtonYorkUnited Kingdom Department of Chemical and Forensic Sciences Botswana International University of Science and TechnologyBotswana

Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological ***,we perform a study of water samples collected from 13 locations distributed across Botswana to obtain the first overview of the nature and distribution of chemical contaminants across the country's aquatic *** resolution mass spectrometry was applied using nontargeted and suspect screening methods to qualitatively analyse samples.A total of 114 contaminants of emerging concern(CeCs)were identified including 68(59.6%)pharmaceuticals and pharmaceutical metabolites;16(14.2%)pesticides;13(11.4%)psychoactive compounds and metabolites;11(9.7%)industrial chemicals and intermediates and lastly,5(4.4%)personal care ***,3,4-dimethylmethcathinone,and diazolidinyl urea represented the most commonly detected pharmaceutical,psychoactive drug and personal care product,*** pesticide dodemorph and three industrial chemicals(stearamide,pthalic acid and bis(2-ethylhexyl)phthalate)were detected in all samples obtained.90 CeCs were detected in receiving water(from 7 sample locations),75 in wastewater(from 3 sample locations)and 60 in surface water(from 9 sample locations).Of the compounds detected,only 8 had been identified in environmental samples acquired in Botswana *** discuss the variations in the nature and frequency of chemical pollutants detected in this work in a geographical *** results indicate that Botswana's aquatic systems are subject to pollution,despite wastewater treatment and that in order to mitigate potentially harmful effects on both human and aquatic ecosystems,more investigations are required to correctly identify,track and tackle the sources of pollution.

关键词： emerging contaminants Chemical pollution Water analysis Pharmaceuticals LC-hRMS/MS

痴心不悔的人文主义者语言与艺术中的表现问题

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新美术 2024年第4期45卷 4-17页

作者： [英]e.h.贡布里希李本正(译) 不详天津美术学院

我的题目改自杰出钢琴家杰拉尔德·穆尔[Gerald Moore]的一本书的书名,你们也许知道,他是世界上一些伟大歌唱家,诸如菲希尔·迪斯考[Fischer Dieskau]等人的伴奏者。穆尔撰写了一部脍炙人口的回忆录,名为《问心无愧的伴奏者》[The Unash... 详细信息

我的题目改自杰出钢琴家杰拉尔德·穆尔[Gerald Moore]的一本书的书名,你们也许知道,他是世界上一些伟大歌唱家,诸如菲希尔·迪斯考[Fischer Dieskau]等人的伴奏者。穆尔撰写了一部脍炙人口的回忆录,名为《问心无愧的伴奏者》[The Unashamed Accompanist],他希望表明,与一些同行不同,他并不为自己在生活中扮演的角色感到难堪,他并不想当一名独奏者或者著名的音乐会钢琴家,也不以为歌唱家伴奏而感到羞愧。恐怕我作为一名人文主义者,还不如杰拉尔德·穆尔作为伴奏者一样出色,但是尽管我常常希望自己能更出色些,我却并不希望换一份别的工作。

关键词：伴奏者人文主义者穆尔杰拉尔德歌唱家钢琴家

A hybrid machine-learning model for solar irradiance forecasting

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Clean energy 2024年第1期8卷 100-110页

作者： Ameera M.Almarzooqi Maher Maalouf Tarek h.M.el-Fouly Vasileios e.Katzourakis Mohamed S.el Moursi Constantinos V.Chrysikopoulos Department of Industrial and Systems engineering Khalifa UniversityAbu DhabiPO Box 127788UAE electrical engineering and Computer Science Department Khalifa University Abu DhabiUAE Department of Civil Infrastructure and environmental engineering Khalifa UniversityAbu DhabiPO Box 127788UAE School of Chemical and environmental engineering Technical University of CreteChaniaGreece

Nowcasting and forecasting solar irradiance are vital for the optimal prediction of grid-connected solar photovoltaic(PV)power *** plants face operational challenges and scheduling dispatch difficulties due to the fluctuating nature of their power *** the generation capacity within the electric grid increases,accurately predicting this output becomes increasingly essential,especially given the random and non-linear characteristics of solar irradiance under variable weather *** study presents a novel prediction method for solar irradiance,which is directly in correlation with PV power output,targeting both short-term and medium-term forecast *** proposed hybrid framework employs a fast trainable statistical learning technique based on the truncated-regularized kernel ridge regression *** proposed method excels in forecasting solar irradiance,especially during highly intermittent weather periods.A key strength of our model is the incorporation of multiple historical weather parameters as inputs to generate accurate predictions of future solar irradiance values in its scalable *** evaluated the performance of our model using data sets from both cloudy and sunny days in Seattle and Medford,USA and compared it against three forecasting models:persistence,modified 24-hour persistence and least *** on three widely accepted statistical performance metrics(root mean squared error,mean absolute error and coefficient of determination),our hybrid model demonstrated superior predictive accuracy in varying weather conditions and forecast horizons.

关键词： solar power generation kernel ridge regression hybrid model forecasting

Improving the utility of locally differentially private protocols for longitudinal and multidimensional frequency estimates

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Digital Communications and Networks 2024年第2期10卷 369-379页

作者： héber h.Arcolezi Jean-François Couchot Bechara Al Bouna Xiaokui Xiao Inria andÉcole Polytechnique(IPP) PalaiseauFrance Femto-ST Institute Univ.Bourg.Franche-ComtéUBFCCNRSBelfortFrance TICKeT Lab. Antonine University Hadat-BaabdaBaabdaLebanon School of Computing National University of SingaporeSingaporeSingapore

This paper investigates the problem of collecting multidimensional data throughout time(i.e.,longitudinal studies)for the fundamental task of frequency estimation under Local Differential Privacy(LDP)*** to frequency estimation of a single attribute,the multidimensional aspect demands particular attention to the privacy ***,when collecting user statistics longitudinally,privacy progressively ***,the“multiple”settings in combination(i.e.,many attributes and several collections throughout time)impose several challenges,for which this paper proposes the first solution for frequency estimates under *** tackle these issues,we extend the analysis of three state-of-the-art LDP protocols(Generalized Randomized Response–GRR,Optimized Unary encoding–OUe,and Symmetric Unary encoding–SUe)for both longitudinal and multidimensional data *** the known literature uses OUe and SUe for two rounds of sanitization(***),i.e.,L-OUe and L-SUe,respectively,we analytically and experimentally show that starting with OUe and then with SUe provides higher data utility(i.e.,L-OSUe).Also,for attributes with small domain sizes,we propose Longitudinal GRR(L-GRR),which provides higher utility than the other protocols based on unary ***,we also propose a new solution named Adaptive LDP for LOngitudinal and Multidimensional FRequency estimates(ALLOMFRee),which randomly samples a single attribute to be sent with the whole privacy budget and adaptively selects the optimal protocol,i.e.,either L-GRR or *** shown in the results,ALLOMFRee consistently and considerably outperforms the state-of-the-art L-SUe and L-OUe protocols in the quality of the frequency estimates.

关键词： Local differential privacy Discrete distribution estimation Frequency estimation Multidimensional data Longitudinal studies

The effect of the concentration of plastic waste on the formation of reaction products of the Ti–PeT system

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Green Chemical engineering 2024年第3期5卷 374-382页

作者： Aleksey e.Matveev Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences

The paper presents research results of the synthesis, phase composition, and structure of products obtained by highly exothermic reactions between Ti and C10h8O4mixture components, depending on the plastic waste concentration and Ti powder dispersiveness, density of initial samples, and synthesis medium. The dependence of the phase composition and structure of the synthesis products on the concentration of the polymer（plastic）component in the initial Ti-PeT(C10h8O4) system was found. When the plastic waste content is 20 wt% to 25 wt%, synthesis products contain TiC0.5O0.5–TiC0.6–0.75particle agglomerates. Further growth in the polyethylene terephthalate content from 30 wt% to 45 wt% leads to the formation of synthesis products consisting of titanium carbide(TiC0.6–1.0). The gaseous byproduct composition of the exothermic reaction is investigated for the Ti–-C10h8O4mixture composition. It is found that the gaseous by-product mostly contains hydrogen and carbon monoxide as well as impurities of different hydrocarbons（methane, acetylene, ethane, ethene） and carbon dioxide. The maximum adiabatic temperature of the gas combustion temperature is 2080℃, which demonstrates the possibility of using gas as a fuel for energy generation devices. Based on the data obtained, it is possible to create a basis for a new plastic waste technology to fabricate carbide-containing materials.

关键词： Plastic waste Titanium carbide Green technology hydrogen synthesis

event-triggered h_(∞) consensus control for input-constrained multi-agent systems via reinforcement learning

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Control Theory and Technology 2024年第1期22卷 25-38页

作者： Jinxuan Zhang Chang-e Ren College of Information engineering Capital Normal UniversityBeijing100089China

This article presents an event-triggered h_(∞) consensus control scheme using reinforcement learning (RL) for nonlinear second-order multi-agent systems (MASs) with control constraints. First, considering control constraints, the constrained h_(∞) consensus problem is transformed into a multi-player zero-sum game with non-quadratic performance functions. Then, an event-triggered control method is presented to conserve communication resources and a new triggering condition is developed for each agent to make the triggering threshold independent of the disturbance attenuation level. To derive the optimal controller that can minimize the cost function in the case of worst disturbance, a constrained hamilton–Jacobi–Bellman (hJB) equation is defined. Since it is difficult to solve analytically due to its strongly non-linearity, reinforcement learning (RL) is implemented to obtain the optimal controller. In specific, the optimal performance function and the worst-case disturbance are approximated by a time-triggered critic network;meanwhile, the optimal controller is approximated by event-triggered actor network. After that, Lyapunov analysis is utilized to prove the uniformly ultimately bounded (UUB) stability of the system and that the network weight errors are UUB. Finally, a simulation example is utilized to demonstrate the effectiveness of the control strategy provided.

关键词： h_(∞)optimal control Input constrains Multi-agent systems(MASs) Reinforcement learning(RL)

DNA metabarcoding reveals seasonal changes in diet composition across four arthropod-eating lizard species(Phrynosomatidae:Sceloporus)

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Integrative Zoology 2024年第3期19卷 480-495页

作者： Mauricio heRNÁNDeZ Stephanie heReIRA-PACheCO Antton ALBeRDI Aníbal h.DÍAZ De LA VeGA-PÉReZ Arturo eSTRADA-TORReS Sergio ANCONA Yendi e.NAVARRO-NOYA Doctorado en Ciencias Biológicas Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico estación Científica La Malinche Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Center for evolutionary hologenomics The Globe InstituteUniversity of CopenhagenCopenhagenDenmark Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de TlaxcalaTlaxcalaMexico Departamento de ecología evolutiva Instituto de EcologíaUniversidad Nacional Autónoma de MéxicoMexico CityMexico Laboratorio de Interacciones Bióticas Centro de Investigación en Ciencias BiológicasUniversidad Autónoma de TlaxcalaSan Felipe IxtacuixtlaTlaxcalaMexico

Diet composition and its ecological drivers are rarely investigated in coexisting closely related *** used a molecular approach to characterize the seasonal variation in diet composition in four spiny lizard species inhabiting a mountainous *** metabarcoding revealed that the lizards Sceloporus aeneus,***,***,and *** mostly consumed arthropods of the orders hemiptera,Araneae,hymenoptera,and *** terrestrial lizards *** and *** mostly predated ants and spiders,whereas the arboreal–saxicolous *** and saxicolous *** largely consumed grasshoppers and *** taxonomic and phylogenetic diversity of the prey was higher during the dry season than the rainy season,likely because reduced prey availability in the dry season forced lizards to diversify their diets to meet their nutritional *** and phylogenetic composition varied seasonally depending on the species,but only dietary composition varied with *** dietary turnover was greater in *** than in ***,suggesting site-specific seasonal variability in prey availability;no other differences among species were ***,which lives at the highest altitude in our study site,displayed interseasonal variation in diet *** differences were correlated with the species’feeding strategies and elevational distribution,which likely contributed to the coexistence of these lizard species in the studied geographic area and beyond.

关键词： arthropod-eating lizards diet breadth environmental barcoding mountainous ecosystem seasonal dietary shifts

Organ Abscission in Plants: With Special emphasis on Bell Pepper

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Phyton-International Journal of experimental Botany 2024年第7期93卷 1467-1484页

作者： Ramiro Reyes-Castro héctor G.Núñez-Palenius Juan I.Valiente-Banuet María e.Sosa-Morales Blanca e.Orosco-Alcalá Rafael Guzmán-Mendoza Graciela M.L.Ruiz-Aguilar Rogelio Costilla-Salazar Life Sciences Division Universidad de GuanajuatoIrapuato36500México School of engineering and Sciences Tecnologico de MonterreyQuerétaro76130México

Bell pepper(Capsicum annuum L.),along with potato and tomato,is one of the three most cultivated vegetables in the *** pepper is worldwide accepted due to its characteristics of color,smell,ﬂavor,and *** pepper is also considered a nutritious food due to its vitamin and antioxidant *** Mexico,bell pepper production has a high value because it is grown for the international markets,particularly the United States of ***,the abscission ofﬂowers and fruits is a factor that limits the yield,hinders the planning of activities,and causes a variation in the prices of *** to the importance of this process,in this work we did a bibliometric analysis and literature review of scientiﬁc advances for the understanding of the abscission pro-cess in plants,and in particular for the bell ***,we introduce new perspectives that would help direct future research about organ abscission in ***,the lack of research that would further clarify abscis-sion process in the bell pepper plant is discussed.

关键词： Capsicum annuum abscission zone plant growth regulators environmental factors