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Nonlinear dynamic modeling of planar moving timoshenko beam considering non-rigid non-elastic axial effects

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 479-496页

作者： M.ABBASI GAVArI M.r.HOMAEINEZHAD Faculty of Mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).then,the assumed mode method(AMM)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(AMM) nonlinear motion analysis

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

Clinical validation of the early embryo viability assessment system: Analysis for the blastocyst morphology and pregnancy outcomes

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Asian pacific Journal of reproduction 2024年第5期13卷 219-227页

作者： Vu D Hop An M Cuong Phi t t Anh Nguyen t L Huong Le Hoang Nguyen V Hanh Assisted reproductive technology Centre Tam Anh General HospitalHanoiVietnam Institute of Biotechnology Vietnam Academy of Science and TechnologyHanoiVietnam

Objective:to determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy ***:this retrospective cohort study was conducted on 291 intracytoplasmic sperm injection cycles including 2522 embryos with indications of prolonging embryo culture to the blastocyst stage in the Genea embryo review incubator,and 511 single vitrified-warmed blastocyst transfer cycles from January 2020 to June *** EEVA system produced an EEVA score from E1(best)to E5(worse)for the potential of blastocyst *** morphology was *** association between the EEVA score and each type of blastocyst morphology,implantation rate,clinical pregnancy,and ongoing pregnancy were assessed using generalized estimating ***:the inner cell mass A(ICM A),trophectoderm A(tE A),blastocoele expansion degree of 3,4,5,6,7 rates were higher with lower the EEVA *** adjusted odd ratio(aOr)(E5 vs E1)was 0.3 for ICM A,0.174 for tE A and 0.210 for BL3,4,5,6,7(all Pting a significant association between lower EEVA scores and improved embryo *** implantation,clinical pregnancy,and ongoing pregnancy rate were also higher with lower the EEVA *** aOr of E5 vs E1 was 0.245 for implantation,0.185 for clinical pregnancy and 0.200 for ongoing pregnancy rate(Pthere were associations between blastocyst morphology,pregnancy outcome and EEVA *** good blastocyst morphology and pregnancy outcomes are higher with lower the EEVA score.

关键词： Automated embryo assessment Blastocyst Early embryo viability assessment Genea embryo review incubator

Classification of Conversational Sentences Using an Ensemble Pre-trained Language Model with the Fine-tuned Parameter

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Computers, Materials & Continua 2024年第2期78卷 1669-1686页

作者： r.Sujatha K.Nimala Department of Networking and Communications SRM Institute of Science and TechnologyKattankulathurChengalpattuTamilnadu603203India

Sentence classification is the process of categorizing a sentence based on the context of the *** categorization requires more semantic highlights than other tasks,such as dependence parsing,which requires more syntactic *** existing strategies focus on the general semantics of a conversation without involving the context of the sentence,recognizing the progress and comparing *** ensemble pre-trained language model was taken up here to classify the conversation sentences from the conversation *** conversational sentences are classified into four categories:information,question,directive,and *** classification label sequences are for analyzing the conversation progress and predicting the pecking order of the *** of Bidirectional Encoder for representation of transformer(BErt),robustly Optimized BErt pretraining Approach(roBErta),Generative Pre-trained transformer(GPt),DistilBErt and Generalized Autoregressive Pretraining for Language Understanding(XLNet)models are trained on conversation corpus with *** tuning approach is carried out for better performance on sentence *** Ensemble of Pre-trained Language Models with a Hyperparameter tuning(EPLM-Ht)system is trained on an annotated conversation *** proposed approach outperformed compared to the base BErt,GPt,DistilBErt and XLNet transformer *** proposed ensemble model with the fine-tuned parameters achieved an F1_score of 0.88.

关键词： Bidirectional encoder for representation of transformer conversation ensemble model fine-tuning generalized autoregressive pretraining for language understanding generative pre-trained transformer hyperparameter tuning natural language processing robustly optimized BErt pretraining approach sentence classification transformer models

Modified Black Widow Optimization-Based Enhanced threshold Energy Detection technique for Spectrum Sensing in Cognitive radio Networks

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2339-2356页

作者： r.Saravanan r.Muthaiah A.rajesh School of Computing SASTRA Deemed UniversityThanjavur613401India School of Electrical&Electronics Engineering SASTRA Deemed UniversityThanjavur613401India

this study develops an Enhanced threshold Based Energy Detection approach(EtBED)for spectrum sensing in a cognitive radio *** threshold identification method is implemented in the received signal at the secondary user based on the square *** proposed method is implemented with the signal transmission of multiple outputs-orthogonal frequency division ***,the proposed method is considered the dynamic detection threshold adjustments and energy identification spectrum sensing technique in cognitive radio *** the dynamic threshold,the signal ratio-based threshold is *** threshold is computed by considering the Modified Black Widow Optimization Algorithm(MBWO).So,the proposed methodology is a combination of dynamic threshold detection and *** general threshold-based detection technique has different limitations such as the inability optimal signal threshold for determining the presence of the primary user *** limitations undermine the sensing accuracy of the energy identification ***,the EtBED technique is developed to enhance the energy efficiency of cognitive radio *** projected approach is executed and analyzed with performance and comparison *** proposed method is contrasted with the conventional techniques of theWhale Optimization Algorithm(WOA)and GreyWolf Optimization(GWO).It indicated superior results,achieving a high average throughput of 2.2 Mbps and an energy efficiency of 3.8,outperforming conventional techniques.

关键词： Cognitive radio network spectrum sensing noise uncertainty modified black widow optimization algorithm energy detection technique

Assessment of challenges and strategies for driving energy transitions in emerging markets:A socio-technological systems perspective

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Energy Geoscience 2024年第2期5卷 81-100页

作者： Nelson S.Chipangamate Glen t.Nwaila Wits Mining Institute University of the Witwatersrand1 Jan Smuts Ave.Johannesburg2000South Africa School of Geosciences University of the WitwatersrandPrivate Bag 3Wits2050South Africa

the pursuit of improved quality of life standards has significantly influenced the contemporary mining model in the 21st *** era is witnessing an unprecedented transformation driven by pressing concerns related to sustainability,climate change,the just energy transition,dynamic operating environments,and complex social *** transitions present both opportunities and *** aim of this study is to provide an extensive literature review on energy transition to identify the challenges and strategies associated with navigating transformations in energy *** these transformations is particularly critical in the face of the severe consequences of global warming,where an accelerated energy transition is viewed as a universal *** a socio-technological systems perspective,specifically through the application of Actor Network theory(ANt),this research provides a theoretical foundation while categorising challenges into five distinct domains and outlining strategies across these different *** insights are specifically tailored for emerging market countries to effectively navigate energy transition while fostering the development of resilient ***,our findings highlight that energy transition encompasses more than a mere technological shift;it entails fundamental changes in various systemic socio-economic *** focusing on the role of social structures in transitions,this study makes a significant and innovative contribution to ANt,which has historically been criticised for its limited acknowledgement of social ***,we propose an emerging market energy transition framework,which not only addresses technological aspects,but also integrates social *** framework paves the way for future research and exploration of energy transition *** outcomes of this study offer valuable insights to policymakers,researchers,and practitioners engaged in t

关键词： Actor network theory Energy transition Social innovation technology Actor inclusive policy

A test of the species confidence hypothesis in dusky damselfish

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Current Zoology 2024年第1期70卷 79-86页

作者： Elle Overs Sydney Stump Isabel Severino Daniel t.Blumstein Department of Ecology and Evolutionary Biology University of CaliforniaLos AngelesCA 90095-1606USA

Visual cues are important in both interspecific and intraspecific *** species confidence hypothesis proposes that animals are more attracted to conspecific colors and repelled by colors,not on their *** on terrestrial lizards and birds have tested the species confidence hypothesis and shown that conspecific colors elicit reduced antipredator *** date,the species confidence hypothesis has not been tested in the marine environment,specifically on coral reefs where color communication is of vital *** addressed this knowledge gap by measuring flight initiation distance(the distance an individual moves away from an approaching threat)in dusky damselfish(Stegastes nigricans)in response to an approaching disc of 1 of 4 different color treatments:conspecific,blue,yellow,and *** the species confidence hypothesis explained variation in damselfish flight initiation distance,then we expected individuals to tolerate closer approaches when approached by a conspecific *** addition,we calculated the color difference between each stimulus and its corresponding back-ground as a potential alternative explanation for flight *** tolerated the closest approach from the conspecific color stimulus;there were no significant differences between other colors and there was no support for the alternative color difference *** with similar terrestrial studies,these results are relevant to ecotourists'choice of swimsuit and wetsuit colors because color choice may modify naturalantipredatorbehavior.

关键词： antipredator behavior flight initiation distance risk assessment species confidence hypothesis Stegastes nigricans

Viral and nonviral nanocarriers for in vivo CrISPr-based gene editing

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Nano research 2024年第10期17卷 8904-8925页

作者： Zhongyuan Guo Audrey t.Zhu ronnie H.Fang Liangfang Zhang Aiiso Yufeng Li Family Department of Chemical and Nano Engineering University of California San DiegoLa JollaCA 92093USA Division of Host-Microbe Systems and therapeutics Department of PediatricsUniversity of California San DiegoLa JollaCA 92093USA

the continued development of clustered regularly interspaced short palindromic repeats(CrISPr)technology has the potential to greatly impact clinical medicine,particularly for disease diagnosis and *** high demand for the in vivo delivery of CrISPr-based therapies,significant challenges *** include rapid degradation by enzymes,inefficient disease site targeting,and the risk of undesired off-target *** platforms,with their tailorable properties,have been engineered to efficiently package CrISPr payloads in various formats,including as plasmid DNA,mrNA,and ribonucleoprotein complexes,for in vivo *** them,recombinant adeno-associated viruses,virus-like particles,and lipid nanoparticles have displayed exceptional *** review will discuss the development of these and other nanocarriers for in vivo CrISPr-based genome editing.

关键词： clustered regularly interspaced short palindromic repeats(CrISPr) in vivo gene editing nanocarriers recombinant adeno-associated viruses(rAAVs) virus-like particle(VLP) lipid nanoparticle(LNP)

Astrocytes dynamically regulate the blood-brain barrier in the healthy brain

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Neural regeneration research 2024年第4期19卷 709-710页

作者： AgnėPociūtė Augustas Pivoriūnas Alexei Verkhratsky Department of Stem Cell Biology State Research Institute Centre for Innovative MedicineVilniusLithuania Faculty of Biology Medicine and HealthThe University of ManchesterManchesterUK Achucarro Centre for Neuroscience IKERBASQUEBasque Foundation for ScienceBilbaoSpain Department of Forensic Analytical toxicology School of Forensic MedicineChina Medical UniversityShenyangLiaoning ProvinceChina

the blood-brain barrier(BBB)(discovered and defined by Max Lewandowsky and Lina Stern,and not,as it is universally,and yet erroneously believed,by Paul Ehrlich(Verkhratsky and Pivoriunas,2023))that separates the nervous system from the circulation is evolutionarily conserved from arthropods to *** primeval BBB of the invertebrates and some early vertebrates was made solely by glial cells and secured(in invertebrates)by septate junctions.

关键词： Ehrlich barrier blood