检索结果-南通市图书馆

Progress in Natural Science:Materials International 2014年第4期24卷 321-328页

作者： Liliana Argueta-figueroa Raúl A.Morales-Luckie Rogelio J.Scougall-Vilchis oscar f.o.ea-mejía School of Medicine Autonomous University State of Mexico (UAEMex)Mexico Department of Materials Science Center for Research in Sustainable Chemistry (CIQS)Autonomous University State of Mexico (UAEMex)Km 14.5Carr.Toluca-AtlacomulcoZC 50200Toluca CityState of MexicoMexico Dental Research Center (CIeao) Autonomous University State of Mexico (UAEMex)Mexico

The antibacterial effect is a desirable property in dental *** of simple methods for the preparation of nanosized metal particles has attracted significant attention because of their future applications due to unusual size-dependent antibacterial ***(Cu),Nickel(Ni) and bimetallic Cu–Ni nanoparticles were prepared by a simple chemical method and their antibacterial activity was tested against the widely used standard human pathogens Staphylococcus aureus(gram-negative) and Escherichia coli(gram-positive).Additionally,these nanoparticles were tested against the dental pathogen Streptococcus *** results are promising for potential use in dental materials science.

关键词： Antibacterial properties Metal nanoparticles Copper nanoparticles Nickel nanoparticles Nano-alloy

Superplasticity of a friction stir processed overaged WE54 magnesium alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第11期10卷 3156-3166页

作者： oscar A.Ruano Marta Alvarez-Leal Alberto orozco-Caballero fernando Carreño Physical Metallurgy Department CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain Department of R&D and programmes Technology Centre of Metal-Mechanical and Transport(CETEMET).Avda.1°de Mayos/n.LinaresJaén2370Spain Department of Mechanical Engineering Chemistry and Industrial DesignPolytechnic University of MadridRonda de Valencia 328012MadridSpain

The coarse-grained WE54 magnesium alloy was heat treated in order to have minimum hardness minimizing the effects of precipitates and solid solution. friction stir processing(fSP) was applied in severe conditions to obtain fine, equiaxed and highly misoriented grains, with grain sizes even less than 1 μm. The high severity of processing demonstrated to have a strong impact in the microstructure. Consequently,the processed materials exhibited excellent superplasticity at the high strain rate 10^(-2)s^(-1), and temperatures between 300 and 400 ℃. The maximum tensile superplastic elongation of 756% was achieved at 400 ℃ thanks to the operation of grain boundary sliding mechanism(GBS). Besides the new data obtained through tensile testing, the paper deals with a transcendental question regarding the large differences in strain rate values at a given stress in the superplastic regime at maximum elongation compared to other magnesium-based alloys. With this is mind, 19 magnesium alloys from 22 different investigations were analyzed to give some light to this behavior that never was treated before. It is proposed that this behavior has to be attributed to the accommodation process, necessary for GBS to occur, which is hindered by reinforcing solutes.

关键词： WE54 magnesium alloy friction stir processing Processing severity Superplasticity Grain boundary sliding Solutes

optimization for performance-based design under seismic demands, including social costs

在线全文

学校读者我要写书评

暂无评论

earthquake Engineering and Engineering Vibration 2015年第2期14卷 315-328页

作者： oscar Moller Ricardo o.foschi Juan P.Ascheri Marcelo Rubinstein Sergio Grossman Instituto de Mecanica Aplicada y Estructuras (IMAE) Facultad Cs.Ex. Ingenieríay Agrimensura Universidad Nacional de Rosario Riobambay Berutti 2000 Rosario Argentina Civil Engineering Department University of British Columbia 6250 Applied Sciences Lane Vancouver B.C. Canada V6T1Z4

Performance-based design in earthquake engineering is a structural optimization problem that has, as the objective, the determination of design parameters for the minimization of total costs, while at the same time satisfying minimum reliability levels for the specifi ed performance criteria. Total costs include those for construction and structural damage repairs, those associated with non-structural components and the social costs of economic losses, injuries and fatalities. This paper presents a general framework to approach this problem, using a numerical optimization strategy and incorporating the use of neural networks for the evaluation of dynamic responses and the reliability levels achieved for a given set of design parameters. The strategy is applied to an example of a three-story offi ce building. The results show the importance of considering the social costs, and the optimum failure probabilities when minimum reliability constraints are not taken into account.

关键词： earthquake engineering performance-based design optimization reliabiliy social costs

An Architecture for Software Engineering Gamification

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2020年第6期25卷 776-797页

作者： oscar Pedreira felix Garcia Mario Piattini Alejandro Cortinas Ana Cerdeira-Pena the Universidade da Coruna Centro de Investigacion CITICLaboratorio de Bases de DatosFacultade de InformaticaElvinaA Coruna15071Spain the Universidad de Castilla-La Mancha Grupo AlarcosEscuela Superior de InformaticaPaseo de la Universidad4Ciudad Real13071Spain.

Gamification has been applied in software engineering to improve quality and results by increasing people’s motivation and engagement.A systematic mapping has identified research gaps in the field,one of them being the difficulty of creating an integrated gamified environment comprising all the tools of an organization,since most existing gamified tools are custom developments or *** this paper,we propose a gamification software architecture that allows us to transform the work environment of a software organization into an integrated gamified environment,i.e.,the organization can maintain its tools,and the rewards obtained by the users for their actions in different tools will mount *** developed a gamification engine based on our proposal,and we carried out a case study in which we applied it in a real software development *** case study shows that the gamification engine has allowed the company to create a gamified workplace by integrating custom-developed tools and off-the-shelf tools such as Redmine,TestLink,or JUnit,with the gamification *** main advantages can be highlighted:(i)our solution allows the organization to maintain its current tools,and(ii)the rewards for actions in any tool accumulate in a centralized gamified environment.

关键词： gamification software engineering gamification architecture gamification engine

Levi and Malcev Theorems for finite-Dimensional Algebras from the Variety Defined by the Identities x^(2)=J(x,y,zu)=0

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2021年第1期28卷 87-90页

作者： oscar Guajardo Garza Marina Rasskazova Liudmila Sabinina Centro de Investigacion en Ciencias UAEMCuernavacaMexico omsk State Technical University pr.Mira 11OmskRussia

We study the variety of binary Lie algebras defined by the identities x^(2)=J(x,y,zu)=0,where J(a,b,c)denotes the Jacobian of a,b,*** on previous work by Carrillo,Rasskazova,Sabinina and Grishkov,in the present articl... 详细信息

关键词： Malcev theorem Levi factor splitting algebra binary Lie algebra

Cubosome nanoparticles for enhanced delivery of mitochondria anticancer drug elesclomol and therapeutic monitoring via sub-cellular NAD(P) H multi-photon fluorescence lifetime imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第5期12卷 991-998页

作者： Ana R.faria oscar f.Silvestre Christian Maibohm Ricardo M.R.Adao Bruno f.B.Silva Jana B.Nieder Department of Nanophotonics Ultrafast Bio- and Nanophotonics GroupINL - International Iberian Nanotechnology LaboratoryAv.Mestre Jose Veiga s/n4715-330 BragaPortugal Department of Life Sciences INL-International Iberian Nanotechnology LaboratoryAv.Mestre Jose Veiga s/n4715-330 BragaPortugal

Elesclomol (ELC) is an anticancer drug inducing mitochondria cytotoxicity through reactive oxygen ***,for the first time,we encapsulate the poorly water soluble ELC in monoolein-based cubosomes stabilized with Pluronic *** uptake and nanocarrier accumulation close to the mitochondria with sub-micrometer distance is identified via three-dimensional (3D) confocal microscopy and edge-to-edge compartment *** monitor the therapeutic effect of the ELC nanocarrier,we apply for the first time,label-free time-lapse multi-photon fluorescence lifetime imaging microscopy (MP-fLIM) to track NAD(P)H cofactors with sub-cellular resolution on live cells exposed to an anticancer *** in vitro cytotoxicity is verified when loading the pre-complexed ELC with copper (ELC-Cu).Importantly,for equivalent copper concentration,cubosomes loaded with ELC-Cu show higher cytotoxicity compared to the free *** novel nanocarrier shows promising features for systemic ELC-Cu administration,and furthermore we establish the MP-fLIM technique for the assessment of anticancer drug delivery systems.

关键词： cubosomes mitoch on dria reactive oxyge n species elesclomol NAD(P)H fluoresce nee lifetime anticancer therapy

Integrated site-specific quantification of faecal bacteria and detection of DNA markers in faecal contamination source tracking as a microbial risk tracking tool in urban Lake ecosystems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of.o.eanology and Limnology 2018年第5期36卷 1629-1642页

作者： oscar omondi DoNDE TIAN Cuicui XIAo Bangding Key Laboratory of Algal Biology of Chinese Academy of Sciences-Lake Restoration Research Group Institute of Hydrobiology Chinese Academy of SciencesWuhan 430072China International College University of Chinese Academy of SciencesBeijing 100049China Egerton University Department of Environmental ScienceP.O.Box 536-20115Egerton-Kenya

The presence of feacal-derived pathogens in water is responsible for several infectious diseases and deaths worldwide. As a solution, sources of fecal pollution in waters must be accurately assessed, properly determined and strictly controlled. However, the exercise has remained challenging due to the existing overlapping characteristics by different members of faecal coliform bacteria and the inadequacy of information pertaining to the contribution of seasonality and weather condition on tracking the possible sources of pollution. There are continued ef forts to improve the faecal Contamination Source Tracking(fCST) techniques such as Microbial Source Tracking(MST). This study aimed to make contribution to MST by evaluating the efficacy of combining site specific quantification of faecal contamination indicator bacteria and detection of DNA markers while accounting for seasonality and weather conditions' eff ects in tracking the major sources of faecal contamination in a freshwater system(Donghu Lake, China). The results showed that the use of cyd gene in addition to lacZ and uidA genes differentiates E. coli from other closely related faecal bacteria. The use of selective media increases the pollution source tracking accuracy. BSA addition boosts PCR detection and increases fCST efficiency. Seasonality and weather variability also influence the detection limit for DNA markers.

关键词： assay contamination faecal bacteria indicator source tracking water quality

Detecting polygenic selection in marine populations by combining population genomics and quantitative genetics approaches

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2016年第6期62卷 603-616页

作者： Pierre-Alexandre GAGNAIRE oscar E. GAGGIoTTI Universite Montpellier 2 Place Eugene Bataillon 34095 Montpellier Cedex 5 France ISEM - CNRS UMR 5554 SMEL 2 rue des Chantiers Sete 34200 France Scottish oceans Institute University of St Andrews East Sands St Andrews KY16 9LB UK

Highly fecund marine species with dispersive life-history stages often display large population sizes and wide geographic distribution ranges. Consequently, they are expected to experience reduced genetic drift, efficient selection fueled by frequent adaptive mutations, and high migration loads. This has important consequences for understanding how local adaptation proceeds in the sea. A key issue in this regard, relates to the genetic architecture underlying fitness traits. Theory predicts that adaptation may involve many genes but with a high variance in effect size. Therefore, the effect of selection on allele frequencies may be substantial for the largest effect size loci, but insignificant for small effect genes. In such a context, the performance of population genomic methods to unravel the genetic basis of adaptation depends on the fraction of adaptive genetic variance explained by the cumulative effect of outlier loci. Here, we address some methodological challenges associated with the detection of local adaptation using molecular approaches. We provide an overview of genome scan methods to detect selection, including those assuming complex demographic models that better describe spatial population structure. We then focus on quantitative genetics approaches that search for genotype-phenotype associations at different genomic scales, including genome-wide methods evaluating the cumulative effect of variants. We argue that the limited power of single locus tests can be alleviated by the use of polygenic scores to estimate the joint contribution of candidate variants to phenotypic variation.

关键词： local adaptation genome scans quantitative genetics genotype-phenotype association polygenic scores.

Latitudinal pattern of the thermal sensitivity of running speed in the endemic lizard Liolaemus multimaculatus

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2022年第4期17卷 619-637页

作者： oscar Aníbal STELLATELLI Laura EVEGA Carolina BLoCK Camila RoCCA Patricio BELLAGAMBA Juan Esteban DAJIL félix Benjamín CRUZ Instituto de Investigaciones Marinas y Costeras(IIMyC) Universidad Nacional de Mar del Plata-CONICETFacultad de Ciencias Exactas y NaturalesMar del PlataArgentina Municipalidad de General Pueyrredón Mar del PlataArgentina Instituto de Investigaciones en Biodiversidad y Medioambiente(INIBIoMA) Universidad Nacional del Comahue-CONICETSan Carlos de BarilocheArgentina

Physiological performance in lizards may be affected by climate across latitudinal or altitudinal *** the coastal dune barriers in central-eastern Argentina,the annual maximum environmental temperature decreases up to 2℃ from low to high latitudes,while the mean relative humidity of the air decreases from 50%to 25%.Liolaemus multimaculatus,a lizard in the family Liolaemidae,is restricted to these coastal *** investigated the locomotor performance of the species at 6 different sites distributed throughout its range in these dune *** inquired whether locomotor performance metrics were sensitive to the thermal regime attributable to *** thermal performance breadth increased from 7%to 82%with latitude,due to a decrease in its critical thermal minimum of up to 5℃ at higher *** from high latitude sites showed a thermal optimum,that is,the body temperature at which maximum speed is achieved,up to 4℃lower than that of lizards from the low *** relatively low temperatures,the maximum running speed of high-latitude individuals was faster than that of low-latitude *** parameters of locomotor performance were labile,decreasing as a function of *** results show populations of *** adjust thermal physiology to cope with local climatic *** suggests that thermal sensitivity responds to the magnitude of latitudinal fluctuations in environmental temperature.

关键词： latitude Liolaemus reptile running speed temperature thermal sensitivity

Characteristics of developing scour-holes at a sand-embedded cylinder

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2008年第3期23卷 258-266页

作者： oscar LINK florian PfLEGER Ulrich ZANKE Dept. of Civil Engineering University of Concepción Edmundo Larenas 270 Concepción Chile.Dr.-Ing. Assistant Prof. Doctoral Research fellow Institute for Hydromechanics Technische Universitt München Arcisstrasse 21 80333 München Germany. Institute for Hydraulic and Water Resources Engineering Darmstadt University of Technology Rundeturmstraβe 1 64283 Germany.Full Prof.

Characteristics of developing scour-holes at a sand-embedded 0.2 m diameter circular cylinder are presented. Non-intrusive, high-resolution topographic measurements of developing scour-holes were made with an experimental installation using a laser distance sensor (LDS) and precision step-motors. A clear-water experiment was conducted with bed shear stress equal to 95% of the critical bed shear stress for the initiation of sediment motion at the undisturbed plane sand bed with a d50 of 0.26 mm. During the running experiment of 21 hours duration, measurements were taken by the LDS in different azimuthal half-planes with θ = 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180o in order to study the spatio-temporal variation of geometric properties in developing scour-holes. After 21 hours, the equilibrium condition was approached, with a scour rate less than d50 per hour. Measurement of maximum scour depth in different azimuthal half-planes at different points in time during the experiment show that scour started at the cylinder side and surrounded the cylinder after about 20% of experiment time. Slopes of developing scour-holes presented three regions with different inclinations, which were attributed to vortex action. Both maximum scour depth and maximum scour radius at different azimuthal half-planes are well correlated with the maximum scour depth at plane with θ = 0o. When providing maximum scour depth at the cylinder front, the presented correlations are useful for simple calculation of scour-hole topography. This work provides an experimental database for advanced numerical simulation for loose sediment hydraulics.

关键词： Scour Bridges Piers Sediment transport Loose sediment hydraulics