检索结果-南通市图书馆

维普期刊数据库

Rapid Determination of Metabolites in Bio-fluid Samples by Raman Spectroscopy and Optimum Combinations of Chemometric Methods

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2011年第11期29卷 2525-2532页

作者：卞希慧陈达蔡文生 grant, Edward 邵学广 esearch Center for Analytical Sciences College of Chemistry Nankai University Tianjin 300071 China Department of Chemistry University of British Columbia Vancouver BC Canada V6T 1Z1

The application of Raman spectroscopic techniques combined with multivariate chemometrics signal processing promise new means for the rapid multidimensional analysis of metabolites non-destructively, with little or no sample preparation and little sensitivity to water. However, Rayleigh scattering, fluorescence and uncontrolled variance present substantial challenges for the accurate quantitative analysis of metabolites at physiological levels in bio- logically varying samples. Effective strategies include the application of chemometrics pretreatments for reducing Raman spectral interference. However, the arbitrary application of individual or combined pretreatment procedures can significantly alter the outcome of a measurement, thereby complicating spectral analysis. This paper evaluates and compares six signal pretreatment methods for correcting the baseline variances, together with three variable se- lection methods for eliminating uninformative variables, all within the context of multivariate calibration models based on partial least squares （PLS） regression. Raman spectra of 90 artificial bio-fluid samples with eight urine metabolites at near-physiological concentrations were used to test these models. The combination of multiplicative scatter correction （MSC）, continuous wavelet transform （CWT）, randomization test （RT） and PLS modeling pre- sented the best performance for all the metabolites. The correlation coefficient （R） between predicted and prepared concentration reached as high as 0.96.

关键词： Raman spectroscopy metabolites bio-fluids chemometrics multivariate calibration variable selection

Cirrhosis and autoimmune liver disease:Current understanding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Hepatology 2016年第28期8卷 1157-1168页

作者： Rodrigo Liberal Charlotte R grant Institute of Liver Studies King’s College London School of Medicine at King’s College Hospital

Primary biliary cirrhosis(PBC),primary sclerosing cholangitis(PSC) and autoimmune hepatitis(AIH) constitute the classic autoimmune liver diseases(AILDs).While AIH target the hepatocytes,in PBC and PSC the targets of the autoimmune attack are the biliary epithelial *** liver injury,associated with chronic AILD,leads to un-resolving inflammation,cell proliferation and the deposition of extracellular matrix proteins by hepatic stellate cells and portal *** cirrhosis,and the resultant loss of normal liver function,inevitably *** with cirrhosis have higher risks or morbidity and mortality,and that in the decompensated phase,complications of portal hypertension and/or liver dysfunction lead to rapid *** diagnosis and monitoring of cirrhosis is,therefore of upmost *** biopsy is currently the gold standard technique,but highly promising non-invasive methodology is under *** transplantation(LT) is an effective therapeutic option for the management of endstage liver disease secondary to AIH,PBC and *** is indicated for AILD patients who have progressed to end-stage chronic liver disease or developed intractable symptoms or hepatic malignancy;in addition,LT may also be indicated for patients presenting with acute liver disease due to AIH who do not respond to steroids.

关键词： Hepatic fibrosis Cirrhosis Myofibroblasts Primary biliary cirrhosis Primary sclerosing cholangitis Autoimmune hepatitis Liver transplantation

Interactions between rodents and weeds in a lowland rice agro-ecosystem:the need for an integrated approach to management

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 2019年第4期14卷 396-409页

作者： Nyo Me HTWE grant R.SINGLETON David E.JOHNSON Plant Protection Division Department of AgricultureMinistry of AgricultureLivestock and IrrigationMyanmar International Rice Research Institute DAPO Box 7777Metro ManilaPhilippines Natural Resources Institute University of GreenwichChatham MaritimeKentUK

Rodents and weeds are important pests to rice crops in Southeast *** interaction between these 2 major pests is poorly *** temperate cereal systems,seeds of grass weeds can be an important food source for rodents and weed cover along crop margins provides important refuge for *** 2012 and 2013,a replicated study(n=4)in Bago,Myanmar compared 4 treatments(rodents and weeds;no rodents and weeds;rodents and no weeds;no rodents and no weeds)each of 0.25 ha in transplanted *** were managed with hand weeding in the wet season,and hand weeding and herbicides in the dry *** fences were installed to exclude *** examined the weed cover and relative abundance of weed species,rodent damage,rodent population dynamics and rice yield loss caused by rodents and *** dominant rodent species was Bandicota *** the dry season,Cyperus difformis was dominant at the tillering stage and Echinochloa crus-galli was the dominant weed species at the booting *** the wet season ***-galli was a dominant weed throughout the *** by rodents was higher in the dry *** were larger economic benefits for best weed management and effective rodent control in the dry season(258 US$/ha)than in the wet season(30 US$/ha).Concurrent control of weeds in and around rice fields combined with coordinated community trapping of rodents during the early tillering stage and ripening stage of rice are recommended management options.

关键词： Bandicota bengalensis Myanmar rice rodents weeds

Small RNA Pathways Are in the Angiosperm Male Present and Functional Gametophyte

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2009年第3期2卷 500-512页

作者： Robert grant-Downton Said Hafidh David Twell Hugh G. Dickinson Department of Plant Sciences South Parks Rd Oxford OX1 3RB UK Department of Biology University of Leicester University Road Leicester LE1 7RH UK

Small non-coding RNAs are essential for development of the sporophyte, the somatic diploid phase of flowering plants. They are integral to key cellular processes such as defense, generation of chromatin structure, and regulation of native gene expression. Surprisingly, very little is known of their presence and function in the male haploid phase of plant development （male gametophyte/pollen grain）, where dramatic cell fate changes leading to gametogenesis occur over just two mitotic divisions. We show that critical components of small RNA pathways are expressed throughout pollen development, but in a pattern that differs from the sporophyte. We also demonstrate that mature pollen accumulates a range of mature microRNAs, the class of small RNA most frequently involved in post-transcriptional regulation of endogenous gene expression. Significantly, these miRNAs cleave their target transcripts in developing pollen-a process that seemingly contributes to the purging of key regulatory transcripts from the mature pollen grain. Small RNAs are thus likely to make a hitherto unappreciated contribution to male gametophyte gene expression patterns, pollen development, and gametogenesis.

关键词： Pollen plant germline small RNA microRNA epigenetics

Sediment transport simulation and design optimization of a novel marsh shoreline protection technology using computational fluid dynamics (CFD) modeling

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 2022年第1期37卷 14-25页

作者： Salman Saki grant Besse Peng Yin Daniel Gang Donald Hayes Department of Civil Engineering University of Louisiana at Lafayette University of Texas at San Antonio U.S.Army Engineer Research and Development Center (ERDC)

Coastal Louisiana has the nation’s most fragile and valuable wetlands,whose loss represents 80% of the total losses in the United *** severely restricted mobility of conventional shoreline protection structures makes them impossible to be *** Wave Suppression and Sediment Collection(WSSC) system is a novel technology of high mobility and compatible with existing shoreline protection *** laboratory studies on WSSC showed great potential for wave reduction and sediment *** current study aimed to optimize the design parameters of WSSC using a validated computational model.A computational fluid dynamics (CFD) model was developed and validated using experimental data from the previous laboratory ***,a parametric analysis was conducted with a focus on the performance optimization of wave reduction and sediment collection with respect to pipe diameter and face *** results showed that the wave reduction efficiency decreased with increasing pipe diameter and face *** contrast,the sediment transport efficiency was enhanced by increasing pipe diameter but was not affected significantly by varying face slopes.

关键词： Breakwaters Computational fluid dynamics Sediment transport Shoreline protection Coastal engineering ANSYS FLUENT

Career Management,A Significant Tool for Employee Retention in the Hotel Industry——A Case Study of Hotels in the Southern Part of Ghana

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Career Management,A Significant Tool for Employee Retention ...

作者： Martin Kobby grant 山东大学

学位级别：硕士

当今世界企业部门面临越来越多的人员流动,公司员工不停进出更换,吸引和留住有价值的员工已成为酒店业日益关注的问题。雇主们在为此问题寻求答案,酒店业的各种人力资源经理也在为员工提供激励和更高的薪酬水平来尽量减少酒店业的劳动... 详细信息

当今世界企业部门面临越来越多的人员流动,公司员工不停进出更换,吸引和留住有价值的员工已成为酒店业日益关注的问题。雇主们在为此问题寻求答案,酒店业的各种人力资源经理也在为员工提供激励和更高的薪酬水平来尽量减少酒店业的劳动力流动。尽管如此,劳动力流动问题仍然存在。员工虽然在工作中获得了更高的薪水和超额福利,但他们仍然离开了他们的组织。研究表明,员工离职的意图是基于员工对其工作价值的个人评估。本论文的研究重点是通过研究高效的职业生涯管理方法来提高酒店行业员工保有率。本论文提出的“酒店职业管理方法”可以通过提高“职业能力”导致员工产生较高“职业满意度”,“职业满意度”可以进一步导致员工“留在工作场所”。论文结构方程建模的结果体现了酒店职业管理的两个方面:“职业评估和定位”以及“职业培训和发展”。从结构方程建模的结果可以看出,“职业评估和定位”对员工“职业能力”的影响是显著的,而“职业培训和发展”则没有太多影响。然而“职业培训与发展”对“职业满意度”具有直接的积极的影响,对员工“留任意向”也具有直接积极的影响。本论文研究结果也证明了“职业能力”与“职业满意度”,“职业满意度”和员工“留任意向”之间的正相关关系。本论文研究的结论是,加纳酒店业的酒店雇主和人力资源经理应认真研究和实践职业管理方法中的“培训和发展”内容,从而提高加纳酒店员工的职业满意度,并提高员工的留任意愿。未来,本论文提出的高效的职业生涯管理方法可以成为留住酒店员工的重要工具。

关键词：酒店管理加纳员工表现竞争

Can an evidence-based fall prevention program be translated for use in culturally diverse communities?

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2014年第1期3卷 32-33,65页

作者： David A.Sleet grant T.Baldwin Centers for Disease Control and Prevention

Older adult falls are a significant public health problem,but one that is amenable to preventive interventions.1,2 Despite the progress made in identifying risk factors,developing efficacious health-related interventions,and promoting evidencebased programs in the community,much work remains before these strategies are broadly available and effectively used to reduce fall-related injuries.3 As Newton and ScottFindlay4 have pointed out,the translation of basic scientific knowledge into clinical studies,and the transformation of clinical studies into improvements in health services and public health practices,remain major obstacles to widespread adoption.

关键词： Can an evidence-based fall prevention program be translated for use in culturally diverse communities

维普期刊数据库

TRANSFORMING-GROWTH FACTOR-PI PREFERENTIALLY INHIBITS THE INDUCTION OF CYTOTOXICITY IN HUMAN T CELLS STIMULATED VIA CD28

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 1993年第2期5卷 19-25页

作者：谢剑伟 grant Gellagher Department of Surgery University of Glasgow Glasgow Royal Infirmary Glasgow G31 2ER. U.K. Department of Surgery University of Glasgow Glasgow Royal Infirmary Glasgow G31 2ER. U.K.enerally TGF-βs are held to down- regulate the growth of immune cells and to inhibit the development of certain differentiated functions such as the induction of LAK activity by IL-2. In the present study the effects of TGF-β1 on the proliferation and cytotoxicity of human PBMC activated by anti-CD3 or and-CD3 plus anti-CD28 was investigated. The results demonstrated that TGF- β1 clearly inhibits the induction of cytotoxic ability in human PBMC stimulated via CD3 or CD3 and CD28 ( P<0. 01) without significantly altering the proliferative response to these stimuli at the tested doses of TGF-β1. Co-stimulation with IL-2 was hardly altered suggesting that TGF-β1 action is affected by the nature of the costimulatory signals.

Generally, TGF-βs are held to down- regulate the growth of immune cells and to inhibit the development of certain differentiated functions, such as the induction of LAK activity by IL-2. In the present study, the effects of TGF-β1 on the proliferation and cytotoxicity of human PBMC activated by anti-CD3 or and-CD3 plus anti-CD28 was investigated. The results demonstrated that TGF- β1 clearly inhibits the induction of cytotoxic ability in human PBMC stimulated via CD3 or CD3 and CD28 ( P<0. 01) , without significantly altering the proliferative response to these stimuli, at the tested doses of TGF-β1. Co-stimulation with IL-2 was hardly altered, suggesting that TGF-β1 action is affected by the nature of the costimulatory signals.

关键词： TGF-β Gytotoxlty Human T cell CD28

维普期刊数据库

Revealing and exploiting hierarchical material structure through complex atomic networks

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2017年第1期3卷 163-170页

作者： Sebastian E.Ahnert William P.grant Chris J.Pickard Theory of Condensed Matter Group Cavendish LaboratoryUniversity of CambridgeJJ Thomson AvenueCambridge CB30HEUK Sainsbury Laboratory University of CambridgeBateman StreetCambridge CB21LRUK Department of Materials Science&Metallurgy University of Cambridge27 Charles Babbage RoadCambridge CB30FSUK Advanced Institute for Materials Research Tohoku University 2-1-1 KatahiraAobaSendai 980-8577Japan

One of the great challenges of modern science is to faithfully model,and understand,matter at a wide range of *** with atoms,the vastness of the space of possible configurations poses a formidable challenge to any simulation of complex atomic and molecular *** introduce a computational method to reduce the complexity of atomic configuration space by systematically recognising hierarchical levels of atomic structure,and identifying the individual *** a list of atomic coordinates,a network is generated based on the distances between the *** the technique of modularity optimisation,the network is decomposed into *** procedure can be performed at different resolution levels,leading to a decomposition of the system at different scales,from which hierarchical structure can be *** considering the amount of information required to represent a given modular decomposition we can furthermore find the most succinct descriptions of a given atomic *** straightforward,automatic and general approach is applied to complex crystal *** show that modular decomposition of these structures considerably simplifies configuration space,which in turn can be used in discovery of novel crystal structures,and opens up a pathway towards accelerated molecular dynamics of complex atomic *** power of this approach is demonstrated by the identification of a possible allotrope of boron containing 56 atoms in the primitive unit cell,which we uncover using an accelerated structure search,based on a modular decomposition of a known dense phase of boron,γ-B_(28).

关键词： structure atomic complex