检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2016年第7期37卷 903-918页

作者： R.ANSARI t.POURASHRAF R.GHOLAMI H.ROUHI Department of Mechanical Engineering University of Guilan Department of Mechanical Engineering Lahijan BranchIslamic Azad University Department of Engineering Science Faculty of Technology and Engineering East of GuilanUniversity of Guilan

the size-dependent nonlinear buckling and postbuckling characteristics of circular cylindrical nanoshells subjected to the axial compressive load are investigated with an analytical approach. the surface energy effects are taken into account according to the surface elasticity theory of Gurtin and Murdoch. the developed geometrically nonlinear shell model is based on the classical Donnell shell theory and the von Karman＇s hypothesis. With the numerical results, the effect of the surface stress on the nonlinear buckling and postbuckling behaviors of nanoshells made of Si and Al is studied. Moreover, the influence of the surface residual tension and the radius-to-thickness ratio is illustrated. the results indicate that the surface stress has an important effect on prebuckling and postbuekling characteristics of nanoshells with small sizes.

关键词： cylindrical nanoshell surface stress nonlinear buckling postbuckling analytical method

Hepatitis B Virus X Protein Sensitizes Primary Mouse Hepatocytes to Ethanol-and tNF-α-Induced Apoptosis by a Caspase-3-Dependent Mechanism

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2005年第1期2卷 40-48页

作者： Won-HoKim FengHong BarbaraJaruga ZhengshengZhang SaijunFan t.JakeLiang BinGao SectiononLiverBiology LaboratoryofPhysiologicStudiesNationalInstituteonAlcoholAbuseandAlcoholismNationalInstitutesofHealthBethesdaMD20892USA. LiverDiseasesBranch NationalInstituteofDiabetesandDigestiveandKidneyDiseasesNationalInstitutesofHealthBethesdaMD20892USA. DepartmentofOncology LombardiCancerCenterGeorgetownUniversity3970ReservoirRoadNWWashingtonDC20057USA.

It is well-documented that alcohol drinking together with hepatitis viral infection accelerates liver injury;however the underlying mechanisms remain *** this paper,we demonstrated that primary hepatocytes from transgenic mice overexpressing hepatitis B virus X protein(HBX)were more susceptible to ethanol- and tNF-α- induced apoptotic *** to normal control mouse hepatocytes,ethanol and/or tNF-α treatment led to a significant increase in reactive oxygen species,mitochondrial permeability transition,cytochrome C release, caspase-3 activity,and poly(ADP-ribose)polymerase degradation in hepatocytes from HBX transgenic mice. Blocking caspase-3 activity antagonized ethanol-and tNF-α-induced apoptosis in primary hepatocytes from HBX transgenic *** together,our findings suggest that HBX sensitizes primary mouse hepatocytes to ethanol- and tNF-α-induced apoptosis by a caspase-3-dependent mechanism,which may partly explain the synergistic effects of alcohol consumption and hepatitis B virus infection on liver *** & Molecular Immunology. 2005;2(1):40-48.

关键词： HBV X protein ethanol apoptosis tNF-α caspase-3

Modelling of the behavior of marine oil spills: applications based on random walk techniques

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2000年第1期12卷 3-8页

作者： Li, Zhi-Wei Mead, Christopher t. Zhang, Shu-Shen Dept. of Environ. Sci. and technol. Dalian University of Technology Dalian 116012 China HR Wallingford Howbery Park Wallingford Oxon OX10 8BA United Kingdom

A numerical model has been developed to simulate the transport and fate of oil spilled at sea. the model combines the transport and fate processes of spilled oil with the random walk technique. Oil movement under the influence of tidal currents, wind driven currents, and turbulent eddies is simulated by the PLUME RW dispersion model developed by HR Wallingford. the weathering processes in the model represent physical and chemical changes of soil slicks with time, and comprise mechanical spreading, dispersion, evaporation and emulsification. Shoreline stranding is determined approximately using a capacity method for different shoreline types. this paper presents details of the model, and describe the results of various sensitivity tests. the model is suitable for oil spill contingency planning.

关键词： oil spill modelling random walk technique CLC number: tQ021 4 Document code: A

Influence of Quantal and Statistical Fluctuations on Phase transitions in Finite Nuclei

在线全文

学校读者我要写书评

暂无评论

Communications in theoretical Physics 2011年第10期56卷 718-726页

作者： G.Kanthimathi N.Boomadevi t.R.Rajasekaran R.M.D.Engineering College R.S.M.NagarKavaraipettai-601206Tamil NaduIndia Department of Physics Manonmaniam Sundaranar UniversityTirunelveli-627012Tamil NaduIndia

Investigations on thermal evolution of pairing-phase transition and shape-phase transition in light nuclei are made as a function of pair gap, deformation, temperature and angular momentum using a finite temperature statistical approach with main emphasis to fluctuations. the occurrence of a peak structure in the specific heat predicted as signals of the pairing-phase and shape-phase transitions are reviewed and it is found that they are not actually true phase transitions and it is only an artifact of the mean field models. Since quantal number and spin fluctuations and statistical fluctuations in pair gap, deformation degrees of freedom and energy when incorporated, it wash out the pairing-phase transition and smooth out the shape-phase transition. Phase transitions due to collapse of pair gap and deformation is discussed and a clear picture of pairing-phase transition in light nuclei is presented in which pairing transition is reconciled.

关键词： phase transitions specific heat fluctuations

支气管或肺动脉化学栓塞治疗不能切除和不能消融的肺转移瘤：一项一期临床研究

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2022年第1期 108-109页

作者： F.E.Boas N.E.Kemeny C.t.Sofocleous R.yeh V.R.thompson M.Hsu 曹秋婷

摘要肺化学栓塞术是一种新兴的治疗肺肿瘤的方法，但最佳的栓塞剂、药物及技术尚不明确。目的探讨用乙碘化油、丝裂霉素和微球进行支气管或肺动脉化学栓塞肺转移瘤

关键词：

Raman Scattering Study of ND_(4)^(+)-Ion Motion and Structural Phase transitions in(ND_(4))_(2)PbCl_(6)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 1996年第5期13卷 394-396页

作者： SHI Jin-rong XU yong-chen y.Kume B.Arnscheidt J.Pelzl WU Xiang Pohl Institute of Solid State Physics Tongji UniversityShanghai 200092 Faculty of General Education Azabu UniversityFuchinobeSagatniharaKanagazva 229Japan Institut fur ExperimentalphysikⅢ AG Festkorperspektroskopie y Ruhr-Universitat Bochum44780 BochumGermany International Center for Materials Physics Chinese Academy of SciencesShenyany 110015

Rams spectra of the internal modes of ND^(+)_(4)-ion in (ND_(4))_(2)PbCl_(6) crystal have been recorded in the temperature range of 5-300 K.A new structural phase tratisition was observed at 34 K be-ca-use of deuterium *** behaviours of the internal modes of the ND 4-ion at this temperature show that the structural transition is one of first order.

关键词： effect. (4) transition

Cellular mechanisms regulating sperm-zona pellucida interaction

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 2011年第1期13卷 88-96页

作者： Andrew t Reid Kate Redgrove R John Aitken Brett Nixon Reproductive Science Group Discipline of Biological Sciences School of Environmental and Life Sciences University of Newcastle Callaghan NSW 2308 Australia ARC Centre of Excellence in Biotechnology and Development Discipline of Biological Sciences School of Environmental and Life Sciences University of Newcastle CaUaghan NSW 2308 Australia

For mammalian spermatozoa to exhibit the ability to bind the zona pellucida （ZP） they must undergo three distinct phases of maturation, namely, spermatogenesis （testis）, epididymal maturation （epididymis） and capacitation （female reproductive tract）. An impressive array of spermatozoa surface remodeling events accompany these phases of maturation and appear critical for recognition and adhesion of the outer vestments of the oocyte, a structure known as the ZP. It is becoming increasingly apparent that species-specific zona adhesion is not mediated by a single receptor. Instead, compelling evidence now points toward models implicating a multiplicity of receptor-ligand interactions. this notion is in keeping with emerging research that has shown that there is a dynamic aggregation of proteins believed to be important in sperm-ZP recognition to the regions of sperm that mediate this binding event. Such remodeling may in turn facilitate the assembly of a multimeric zona recognition complex （MZRC）. though formation of MZRCs raises questions regarding the nature of the block to polyspermy, formation and assembly of such a structure would no doubt explain the strenuous maturation process that sperm endure on their sojourn to functional maturity.

关键词： capacitation fertilization spermatozoa sperm-zona pellucida interaction

Probiotic bacteria change Escherichia coli-induced gene expression in cultured colonocytes:Implications in intestinal pathophysiology

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 Gastroenterology 2007年第47期13卷 6370-6378页

作者： Pinaki Panigrahi Gheorghe t Braileanu Hegang Chen O Colin Stine Departments of Pediatrics University of Maryland School of Medicine 22 South Greene Street Baltimore MD 21201 United States Department of Epidemiology & Preventive Medicine University of Maryland School of Medicine 22 South Greene Street Baltimore MD 21201 United States Genomics Core University of Maryland School of Medicine 22 South Greene Street Baltimore MD 21201 United States

AIM: to investigate the change in eukaryotic gene expression profile in Caco-2 cells after infection with strains of Escherichia coli and commensal probiotic bacteria. MEtHODS: A 19 200 gene/expressed sequence tag gene chip was used to examine expression of genes after infection of Caco-2 cells with strains of normal flora E. coli,Lactobacillus plantarum,and a combination of the two. RESULtS: the cDNA microarray revealed up-regulation of 155 and down-regulation of 177 genes by E. coli . L. plantarum up-regulated 45 and down-regulated 36 genes. During mixed infection,27 genes were up-regulated and 59 were down-regulated,with nullification of stimulatory/inhibitory effects on most of the genes. Expression of several new genes was noted in this group. CONCLUSION: the commensal bacterial strains used in this study induced the expression of a large number of genes in colonocyte-like cultured cells and changed the expression of several genes involved in important cellular processes such as regulation of transcription,protein biosynthesis,metabolism,cell adhesion,ubiquitination,and apoptosis. Such changes induced by the presence of probiotic bacteria may shape the physiologic and pathologic responses they trigger in the host.

关键词： Lactobacillus Escherichia coli Gene expression Probiotic cDNA microarray

Impact of lanthanum on the modification of HfO_2 films structure

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 Rare Earths 2015年第8期33卷 857-862页

作者： t.P.Smirnova L.V.yakovkina V.O.Borisov Nikolaev Institute of Inorganic Chemistry SB RAS

LaxHf1-xOy thin films with various concentrations of La, homogeneous and nonhomogeneous distributions of elements throughout the films thickness was purposefully grown by CVD. the composition of the films and their chemical structures were characterized throughout the films thickness by X-ray photoelectron spectroscopy （XPS） and energy-dispersive X-ray spectrometry （EDXA）. A full picture of the film crystallinity was provided by the combination of grazing incidence X-ray diffraction （GIXRD） synchrotron radiation （SR） and high resolution transmission electron microscopy （HR tEM）. It was shown that La acted as ＂molar volume modulator＂ and stabilized the nonequilibrium at t≤1300 ℃ cubic phases. the samples with La content in range of 7 at.%〈CLa〈22 at.% were materials with fluorite-type （Fm-3m） structure. the pyroehlore phase formation was observed at -18 at.% La content. the correlation between the La-doped content and the films microstructure was revealed.

关键词： Hf1-xLaxOy films solid solutions X-ray diffraction microstructure rare earths

A population study of fasting time and serum prostate-specific antigen （PSA） level

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2014年第5期16卷 740-744,I0009,I0010页

作者： Cheryl K Lau Maggie Guo Jeannine A Viczko Christopher t Naugler Calgary Laboratory Services Calgary Department of Family Medicine University of Calgary Calgary Canada Department of Pathology and Laboratory Medicine Department of Family Medicine University of Calgary Calgary Canada

Prostate cancer is one of the most common cancers in men. traditional screening and diagnostic methods include digital rectal examinations （DREs）, biopsies and serum prostate-specific antigen （PSA） tests, with the latter being the more popular. PSA is a biomarker for prostate cancer; however, it is highly sensitive to external factors as well as other prostate diseases. As such, the reliability of of the serum PSA level as a sole screening and diagnostic tool for prostate cancer is controversial. Recently, it has been shown that fasting extremes can affect concentrations of serum chemistry analytes, thus raising the question of whether or not fasting has an effect on the highly sensitive PSA biomarker. Patients testing for serum PSA levels are often concomitantly submitting to other tests that require fasting, subjecting certain patients to a fasting PSA level while others not. the objective of this study was to investigate whether this discrepancy in fasting state translates into an effect on serum PSA levels. Serum PSA levels and fasting time records for 157 276 men who underwent testing at Calgary Laboratory Services （CLS; Calgary, Alberta, Canada） between 01 January 2010 and 31 March 2013 were accessed. Linear regression models of mean PSA levels and fasting times revealed a statistically important relationship at certain fasting times. Applying a dynamic mathematical model to explore the clinical effect of fasting suggests minimal impact on serum PSA result interpretation. thus, patients can be tested for serum PSA levels regardless of their fasting state.

关键词： diagnostic test fasting prostate-specific antigen (PSA)