检索结果-南通市图书馆

Practical semen analysis： from A to Z

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2010年第1期12卷 14-20页

作者： charlene Brazil Center for health and the Environment University of California Davis CA 95616 USA

Accurate semen analysis is critical for decisions about patient care, as well as for studies addressing overall changes in semen quality, contraceptive efficacy and effects of toxicant exposure. The standardization of semen analysis is very difficult for many reasons, including the use of subjective techniques with no standards for comparison, poor technician training, problems with proficiency testing and a reluctance to change techniques. The World health Organization （WhO） Semen handbook （2010） offers a vastly improved set of standardized procedures, all at a level of detail that will preclude most misinterpretations. however, there is a limit to what can be learned from words and pictures alone. A WhO- produced DVD that offers complete demonstrations of each technique along with quality assurance standards for motility, morphology and concentration assessments would enhance the effectiveness of the manual. however, neither the manual nor a DVD will help unless there is general acknowledgement of the critical need to standardize techniques and rigorously pursue quality control to ensure that laboratories actually perform techniques ＇according to WhO＇ instead of merely reporting that they have done so. Unless improvements are made, patient results will continue to be compromised and comparison between studies and laboratories will have limited merit.

关键词： andrology laboratory quality assurance semen analysis sperm concentration sperm morphology sperm motility

Presenilins as endoplasmic reticulum calcium leak channels and Alzheimer's disease pathogenesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2011年第8期54卷 744-751页

作者： charlene SUPNET Ilya BEZPROZVANNY Department of Physiology University of Texas Southwestern Medical Center at Dallas

Alzheimer disease(AD) is the most common neurodegenerative disorder worldwide and is at present,*** accumulation of toxic amyloid-beta(Aβ) peptide aggregates in AD brain is thought to trigger the extensive synaptic loss and neurodegeneration linked to cognitive decline,an idea that underlies the'amyloid hypothesis'of AD etiology in both the familal(FAD) and sporadic forms of the *** mutations causing FAD also result in the dysregulation of neuronal calcium(Ca2+) handling and may contribute to AD pathogenesis,an idea termed the'calcium hypothesis'of *** in presenilin proteins account for majority of FAD *** function as catalytic subunit ofγ-secretase involved in generation of Aβ peptide Recently,we discovered that presenilns function as low-conductance,passive ER Ca2+ leak channels,independent of γ-secretase *** further discovered that many FAD mutations in presenilins result in loss of ER Ca2+ leak function activity and Ca2+ overload in the *** results provided potential explanation for abnormal Ca2+ signaling observed in FAD cells with mutations in *** latest work on studies of ER Ca2+ leak channel function of presenilins and implications of these findings for understanding AD pathogenesis are discussed in this article.

关键词： calcium signaling neurodegeneration presenilins Alzheimer's disease gamma-secretase amyloid

hard to fly the nest： A study of body condition and plumage quality in house sparrow fledglings

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2014年第4期60卷 449-459页

作者： charlene LELOUTRE Alice GOUZERh Frederic ANGELIER Centre d'Etudes Biologiques de Chiz6 CNRS F-79360 Villiers en Bois France

Contrary to the nestling phase, the post-fledging phase has been less studied probably because it is challenging to follow the chicks after they fledge. however, this phase is crucial to consider when focusing on the life cycle of individuals because it is associated with new demands： After leaving the nest, individuals have to find their own food and cope with a new set of previously unknown stressors. In this study, we aimed at better understanding how energetically demanding the post-ftedging period is in house sparrows Passer domesticus by measuring several indices of a fledgling＇s state （body condition, fat and muscle scores and plumage quality）. If the energetic demands of the post-fledging period are greater than those of the adult life, we predicted that fledglings should be in lower condition and should have a plumage of lower quality relative to adults. Supporting this prediction, the condition and the plumage of fledglings differed dramatically from those of adults. Interestingly, this difference disappeared in autumn. Overall, our results suggest that the post-fledging period is probably one of the most energetically demanding of the life cycle in this species. Supporting this idea, the resighting probability of fledglings was lower relative to adults. however, resighting probability depends on many factors （mortality, dispersal, habitat use and behaviours） and future studies are necessary to tease apart their relative importance in determining resighting probability [Current Zoology 60 （4）： 449-459, 2014].

关键词： Body condition Fault bar Fat score Muscle score Passer domesticus

Poultry gut health-microbiome functions,environmental impacts,microbiome engineering and advancements in characterization technologies

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 Animal Science and Biotechnology 2022年第2期13卷 338-352页

作者： Christiana Eleojo Aruwa charlene Pillay Martin M.Nyaga Saheed Sabiu Department of Biotechnology and Food Science Faculty of Applied SciencesDurban University of TechnologyP.O.Box 1334Durban 4000South Africa Next Generation Sequencing Unit Division of VirologyFaculty of Heath SciencesUniversity of the Free StateBloemfonteinSouth Africa

The gastrointestinal tract(GIT)health impacts animal *** poultry microbiome has functions which range from protection against pathogens and nutrients production,to host immune system *** in the microbiome have also been linked to prevailing environmental *** poultry birds possess a natural resistance to ***,the exploration of environmental impacts and other relevant factors on poultry growth and health have been *** good performance and growth rate are central to animal production,the host-microbiome relationship remains *** to the emergence of metagenomic techniques,conventional methods for poultry microbiome studies were used and were low-throughput and associated with insufficient genomic data and high cost of ***,the advent of high-throughput sequencing platforms have circumvented some of these shortfalls and paved the way for increased studies on the poultry gut microbiome diversity and ***,we give an up-to-date review on the impact of varied environments on microbiome profile,as well as microbiome engineering and microbiome technology *** is hoped that this paper will provide invaluable information that could guide and inspire further studies on the lingering pertinent questions about the poultry microbiome.

关键词： Disease Environmental impacts Gut microbiome Microbiome engineering Poultry health

Research on Factors Determining Capital Structure of Non-Financial Firms in Sub-saharan Region of Africa

在线全文

学校读者我要写书评

暂无评论

Research on Factors Determining Capital Structure of Non-Fin...

作者： charlene Rufaro Kadzunge 浙江工商大学

学位级别：硕士

非金融公司或企业是一国经济发展非常重要的环节,对于促进一国金融发展具有重要意义。很长一段时间以来,资本结构是公司金融领域里的热门研究主题。资本结构是公司长期债务和股权的最合适组合,也是影响重要公司政策方向的基础,因为它涉... 详细信息

非金融公司或企业是一国经济发展非常重要的环节,对于促进一国金融发展具有重要意义。很长一段时间以来,资本结构是公司金融领域里的热门研究主题。资本结构是公司长期债务和股权的最合适组合,也是影响重要公司政策方向的基础,因为它涉及公司的经营活动以及债务和股权比率。本文以非洲撒哈拉以南地区非金融公司为研究样本,以探究资本结构的影响因素。本文选取了2000年至2020年间54家非金融企业的面板数据。基于hausman检验结果,运用固定效应模型实证分析企业规模、盈利能力等因素对企业资本结构的影响。在单位根检验之后,本文得出结论在5%的显著性水平下,所有变量在第一阶差分后都是平稳的,协整结果表明企业规模、盈利能力等因素与企业资本结构存在长期稳定关系。固定效应模型估计表明,盈利能力和流动性之间存在负相关关系。研究结果支持了对啄序理论的理解。本文还发现企业规模与负债率之间存在显著的相关关系;不同的是,本文发现了利率和资本结构之间并无显著相关性。实证研究结果表明,资本结构是企业规模、利润波动率、盈利能力、流动性和现金波动率等多个变量的函数。正因为这些因素决定了企业的生死存亡,企业积极主动地确定资本结构里的组成部分是至关重要的。

关键词：资本结构现金流波动率收益波动率利率盈利能力流动性规模非洲

Bacteriophage M13 as a Scaffold for Preparing Conductive Polymeric Composite Fibers

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

Nano Research 2008年第3期1卷 235-241页

作者： Zhongwei Niu Michael ABruckman Brandon harp charlene MMello Qian Wang Department of Chemistry and Biochemistry and Nanocenter University of South CarolinaColumbiaSC 29208USA Bioscience and Technology Team US Army Natick Soldier ResearchDevelopment&Engineering CenterNatickMA 01760-5020USA

Using biological templates to build one-dimensional functional materials holds great promise in developing nanosized electrical devices,sensors,catalysts,and energy storage *** this communication,we report a versatile assembly process for the preparation of water-soluble conductive polyaniline(PANi)/M13 composite nanowires by employing the bacteriophage M13 as a *** surface lysine residues of M13 can be derivatized with carboxylic groups to improve its binding ability to the aniline;the resulting modifi ed M13 is denoted as *** negatively-charged poly(sulfonated styrene)was used both as a dopant acid and a stabilizing agent to enhance the stability of the composite fi bers in aqueous solution.A transparent solution of the conductive PANi/m-M13 composite fi bers can be readily obtained without any further purifi cation *** fi bers can be easily fabricated into thin conductive fi lms due to their high aspect ratio and good solubility in aqueous *** synthesis discloses a unique and versatile way of using bionanorods to produce composite fi brillar materials with narrow dispersity,high aspect ratio,and high processibility,which may have many potential applications in electronics,optics,sensing,and biomedical engineering.

关键词： Bacteriophage M13 nanofi ber conductive polymer self-assembly bioconjugation

Mobile EMR Use for Epidemiological Surveillance on a Medical Service Trip in honduras: A Pilot Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

E-health Telecommunication Systems and Networks 2016年第1期5卷 1-7页

作者： Christopher J. Dainton charlene h. Chu Grand River hospital Kitchener Canada University of Toronto Toronto Canada

Rationale: Medical treatment on short-term primary care medical service trips (MSTs) is generally symptom-based and supplemented by point-of-care testing. This pilot study contributes to the effective planning for such austere settings based on predicted symptomology. Objective: We aimed to prospectively document the epidemiology of patients seen during two low-resource clinics on a MST in honduras and apply predefined case definitions adapted from guidelines used by international healthcare organizations (e.g. World health Organization). Methods: An observational design was used to track the epidemiology during two clinics on an MST in Limon, honduras in March 2015. The QuickChart mobile electronic medical record (EMR) application was piloted to document diagnoses according to predefined case definitions. Results: The most commonly diagnosed syndromes were upper respiratory complaints (20.19%), nonspecific abdominal complaints (20.19%), general pain (15.38%), hypertension (9.62%), pruritus (6.73%), and asthma/ COPD (4.81%). The case definitions accounted for 94% of all complaints and diagnoses on the brigade. Discussion: The distribution of common patient diagnoses on this MST was similar to that which had been reported elsewhere. The use of broader symptom-based case definitions for epidemiologic surveillance could also facilitate the syndromic management of patients seen on MSTs, and improve the consistency of treatment offered. Conclusion: Case definitions for common syndromes on primary care MSTs may be a feasible method of standardizing patient management. Preliminary use of the QuickChart EMR was acceptable for documentation of epidemiology in the field. Further study is necessary to investigate the reliability of syndromic diagnostic criteria between different clinicians and in a variety of MST settings.

关键词： Electronic Medical Records Epidemiology Global health Experience Medical Missions Medical Service Trip Primary Care

A comparison of handheld and standard ultrasound in Swiss medical students

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 Emergency Medicine 2022年第2期13卷 85-90页

作者： Mark Slader hayley Young Margot Barker Kylie Prentice Katherine Bogaard charlene Yuan Soheil Saadat Shadi Lahham School of Medicine University of CaliforniaIrvine 92617USA Department of Emergency Medicine University of CaliforniaIrvine 92868USA

BACKGROUND:The use of ultrasound(US)within healthcare has inspired the development of new US *** have been few studies comparing the use of handheld US to standard US for medical *** research aims to determine whether a handheld US device can provide a comparable primary learning experience to that of a standard US ***:Over two days of instruction,participants were taught and evaluated on core US *** standard group received instruction on standard US machines,while the handheld group received instruction on handheld US *** completed a qualitative survey regarding their *** hundred and four images were obtained and graded by two emergency medicine ***:A total of 119 Swiss medical students were enrolled in our *** was no statistically significant difference in the US assessment measurements,except for faster endpoint septal separation(EPSS)vascular setup time in the handheld group(P=0.001).There was no statistically significant difference in participants’perceived difficulty of US learning(P=0.198),comfort level(P=0.188),or self-estimated capability to perform US in the future(P=0.442).There was no statistically significant difference in the percentage of correctly obtained images(P=0.211)or images that were clinically useful(P=0.256).The median quality score of images obtained by the standard group was eight compared to seven in handheld group(Phandheld US machine can perform as well as a standard US machine as an educational tool despite sacrifices in image quality.

关键词： handheld ultrasound Ultrasound education Switzerland Medical education

Transient Absorption of the Chlorophyll a in Ethanol

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2006年第1期19卷 6-10页

作者： Ying Shi Y. J. Shiu charlene Su S.h. Lin Ke-li han State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 115023 Institute of Atomic and Molecular Sciences Academia Sinica.Taipei Department of Chemistry National Taiwan University Taipei

The excited state of Chlorophyll a is *** by ferntosecond transient absorption. The transient absorption spectra of Q band and By band of Chlorophyll a in ethanol have been observed. The fast kinetics of Chlorophyll a which exhibit two ultrafast components were also ineasured. The one is assigned to transient absorption of the inhomogencously broadened ground state absorption spectrum, while the other is the response of the solvent to the change of the electron configuration in the excited state due to solvation dynamics of the polar solvent molecules. To understand the anisotropy of Chlorophyll a in ethanol, the anisotropy profile was also performed by 405 nm excitation and found that the anisotropy profile is 0.143. The possible combination of θda, θdb and η at at excitation of By band has been simulated.

关键词： Femtosecond Chlorophyll a Transient absorption