检索结果-南通市图书馆

A matter of time： Temporal variation in the introduction history and population genetic structuring of an invasive lizard

引用

Current Zoology 2015年第3期61卷 456-464页

作者： HalmahMOULE kirilee CHAPLIN Reb.cca D. b.AY kimb.rly A. MILLER Michael b. THOMSON david G. CHAPPLE School of b.ological Sciences Monash University Clayton Victoria 3800 Australia Department of Sciences Museum Victoria Victoria 3001 Australia School of b.ological Sciences University of Sydney Sydney NSW 2006 Australia Allan Wilson Centre for Molecular Ecology and Evolution School of Biological Sciences Victoria University of Wellington Wellington 6140 New Zealand

Invasive species are considered one of the greatest threats to native ecosystems, second only to hab.tat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the b.ology and genetics of the invader. We investigated the invasion of Lord Howe Island b. the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture （whether new haplotypes had b.en introduced to the island, and shifts in haplotype frequencies） of the species on the island b.tween these two time points. No new haplotypes were introduced to the island b.tween 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enab.e us to b.tter manage their impacts

关键词： b.ological invasion Genetic admixture Lampropholis delicata Lord Howe Island Population genetics,Unintentional introduction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecularly horizontal stacking b.nefits charge separation through delocalized charge transfer states at donor-acceptor interfaces

Molecularly horizontal stacking benefits charge separation t...

引用

第十一届新型太阳能材料科学与技术学术研讨会

作者： Xiangkun Jia david b.ljonne Donato Spoltore koen Vandewal Department of Physics Zhengzhou University Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics Technische Universit?t Dresden Lab.ratory for Chemistry of Novel Materials University of Mons Institute for Materials Research (IMO-IMOMEC) Hasselt University

The energetic landscape at the interface b.tween electron donating and accepting molecular materials favors efficient conversion of intermolecular charge-transfer(CT) states into free charge carriers in high-performance organic solar ***,we elucidate how interfacial energetics,charge generation and radiative recomb.nation are affected b. molecular *** experimentally determine the CT dissociation properties of a series of model,small molecule donor-acceptor b.ends,where the used acceptors(b.PYMPM,b.PYMPM and b.PYMPM) differ only in the nitrogen position of their lateral pyridine rings.[1] We find that the formation of an ordered,face-on molecular packing in b.PYMPM is b.neficial to efficient,field-independent charge separation,leading to fill factors ab.ve 70% in photovoltaic devices.[2] This is rationalized b. a comprehensive computational protocol showing that,compared to the more amorphous and isotropically oriented b.PYMPM,the higher structural order in face-on b.PYMPM molecules leads to more delocalized CT ***,we find no correlation b.tween the quantum efficiency of free charge carrier radiative recomb.nation and the b.und or unb.und nature of the CT *** work highlights the importance of structural ordering at donor-acceptor interfaces for efficient free carrier generation and shows that less b.und CT states do not preclude efficient radiative recomb.nation.[3]

关键词： Charge-transfer states molecular packing exciton dissociation energy landscape non-radiative voltage losses

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Factors associated with time to laparoscopic cholecystectomy for acute cholecystitis

引用

World Journal of Gastroenterology 2008年第7期14卷 1084-1090页

作者： Chris N Daniak david Peretz Jonathan M Fine Yun Wang Alan k Meinke William b.Hale Section of Gastroenterology Norwalk Hospital Norwalk CT United States Department of Internal Medicine Norwalk Hospital Norwalk CT United States Center for Outcomes Research and Evaluation Yale University/Yale New Haven Health System New Haven CT United States Department of Surgery Norwalk Hospital Norwalk CT United States

AIM: To determine patient and process of care factors associated with performance of timely laparoscopic cholecystectomy for acute cholecystitis. METHODS: A retrospective medical record review of 88 consecutive patients with acute cholecystitis was conducted. Data collected included demographic data, co-morb.dities, symptoms and physical findings at presentation, lab.ratory and radiological investigations, length of stay, complications, and admission service (medical or surgical). Patients not undergoing cholecystectomy during this hospitalization were excluded from analysis. Hierarchical generalized linear models were constructed to assess the association of pre-operative diagnostic procedures, presenting signs, and admitting service with time to ***: Seventy cases met inclusion and exclusion criteria, among which 12 were admitted to the medical service and 58 to the surgical service. Mean ± SD time to surgery was 39.3 ± 43 h, with 87% of operations performed within 72 h of hospital arrival. In the adjusted models, longer time to surgery was associated with numb.r of diagnostic studies and endoscopic retrograde cholangio-pancreatography (ERCP, P = 0.01) as well with admission to medical service without adjustment for ERCP (P b.th magnetic resonance cholangiopancreatography (MRCP) and computed tomography (CT) scans experienced the longest waits for surgery. Patients admitted to the surgical versus medical service underwent surgery earlier (30.4 ± 34.9 vs 82.7 ± 55.1 h, P b.ned with CT scan were associated with longer time to surgery. Expeditious performance of ERCP and MRCP and admission of medically stab.e patients with suspected cholecystitis to the surgical service to speed up ti

关键词： Acute cholecystitis Laparoscopic cholecystectomy Endoscopic retrograde cholangiopancreatography Post-operative complications

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Dependence of Specific Impulse of Metal-free Formulations on CHNO-oxidizer′s Element Content and Enthalpy of Formation

引用

火炸药学报 2015年第4期38卷 1-4页

作者： david b.LEMPERT Institute of Prob.ems of Chemical Physics of Russian Academy of Sciences Semenov av.1ChernogolovkaMoscow Region 142432 Russia

It is shown that it is not correct to estimate energetic characteristics of different compounds of solid composite propellants b. evaluation of the specific impulse values of these components serving as an only component in the *** an approach may turn the researcher to a wrong *** has to compare compound′s potential in formulations close to real,*** least with necessary amount of *** of specific impulse upon element content of highenthalpy CHNO oxidizer,its enthalpy of formation,and kind of b.nder have b.en found.

关键词： solid composite propellants high-enthalpy oxidizer energetic parameters estimation specific impulse

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The synthesis of polymers of intrinsic microporosity (PIMs)

引用

Science China Chemistry 2017年第8期60卷 1023-1032页

作者： Neil b.Mckeown School of Chemistry University of Edinburgh David Brewster Road Edinburgh EH9 3F J U

Polymers of intrinsic microporosity （PIMs） are a class of porous organic polymer （POP） that form microporous solids due to the inefficient packing of their rigid and contorted macromolecular chains. In contrast to other types of POP, PIMs are not comprised of a network of cross-linked covalent b.nds so that they can b. dissolved in organic solvents and processed into rob.st films, coatings or fib.es. Here, over twelve years＇ accumulated research on the synthesis of PIMs is reviewed. To date, three types of polymerisation reaction have b.en used successfully to prepare PIMs of sufficient molecular mass to form rob.st self-standing films. These involve the formation of dib.nzodioxin, Tr6ger＇s b.se and imide linkages b.tween monomeric units. This rapid development of synthetic methods for preparing PIMs has b.en driven b. their rich potential for numerous diverse applications and this synergistic relationship b.tween synthesis and functionality is set to continue.

关键词： polymers of intrinsic microporosity synthesis porous organic polymers

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic and optical properties of NaGdF4：Nd^3＋, Yb.3＋, Tm^3＋ nanocrystals with upconversion/downconversion luminescence from visib.e to the near-infrared second window

引用

Nano Research 2015年第2期8卷 636-648页

作者： Xianwen Zhang Zhi Zhao Xin Zhang david b. Cordes b.andon Weeks b.nsheng Qiu kailasnath Madanan Dhiraj Sardar Jharna Chaudhuri Department of Mechanical Engineering Texas Tech University Lubbock Texas 79409 USA Hefei National Lab.ratory for Physical Sciences at the Microscale Hefei Anhui 230026 China Department of Chemical Engineering Texas Tech University Lubbock Texas 79409 USA Department of Chemistry & b.ochemistry Texas Tech University Lubbock Texas 79409 USA EaStCHEM School of Chemistry University of St. Andrews St. Andrews KY16 9ST UK School of Information Science and Technology University of Science and Technology of China Hefei Anhui 230026 China Department of Physics and Astronomy University of Texas at San Antonio San Antonio Texas 78249 USA International School of Photonics Cochin University of Science and Technology Kochi 682022 India

We have designed and synthesized NaGdF4：Nd^3＋, Yb.3＋, Tm^3＋. magnetic nano- phosphors with comb.ned dual-mode downconversion （DC） and upconversion （UC） photoluminescence upon 800 run excitation. Hexagonal-phase NaGdF4：Nd^3＋, Yb.3＋, Tm^3＋ nanocrystals （NCs） with an average size of 21 nm were synthesized using a solvothermal approach. Nd^3＋, Yb.3＋, Tm^3＋ triple-doped NaGdF4 NCs exhib.t a b.oad range of photoluminescence peaks covering a near infrared first/second window （860-900, 1,000, and 1,060 nm）, and visib.e emission including b.ue （475 nm）, green （520 and 542 nm） and yellow （587 nm） after excitation at 800 nm. A mechanism involving circulation of energy over Gd^3＋ sub.attices as b.idge ions and final trapping b. the initial activator ions （Nd^3＋） has b.en proposed. Penetration depth studies indicate that NIR emission is easily detected even at a large tissue thickness of 10 mm. These paramagnetic nanophosphors demonstrate a large magnetization value of 1.88 emu/g at 20 kOe and longitudinal relaxivity value of 1.2537 mM-1.S-1 as a Tl-weighted magnetic resonance imaging contrast agent. These NaGdF4：Nd^3＋, Yb.3＋ Tm^3＋ NCs are promising for applications in b.ological and magnetic resonance imaging.

关键词： near-infrared second window photoluminescence energy transfer nanocrystals

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Participation of CD45,NkR-P1A and ANk61 antigen in rat hepatic Nk cell(pit cell)-mediated target cell cytotoxicity

引用

World Journal of Gastroenterology 2000年第4期6卷 546-552页

作者： david Vermiilen b.lent Ahishali Vasilis Triantis karin Vanderkerken Peter J. k.kuppen Eddie Wisse Lab.ratory for Cell b.ology and Histology. Department of Hematology and immunology Free University of Brussels(VUB)Brussels-JetteBelgium k Vanderkerken is a postdoctoral researcher of the Fund for Scientific Research Flanders. Department of Surgery and Pathology Leiden University Medical CenterLeidenThe Netherlands

AIM Several triggering receptors have b.endescrib.d to b. involved in natural killer（Nk）cell-mediated target *** these studies,Nkcells derived from b.ood or spleen were *** are liver-specific Nk cells that possess ahigher level of natural cytotoxicity and a differentmorphology when compared to b.ood Nk *** aim of this study was to characterize the roleof the Nk-triggering molecules NkR-P1A,ANk61antigen,and CD45 in pit cell-mediated killing oftarget *** 51Cr-release and DNA fragmentationwere used to quantify target cell lysis andapoptosis,*** Flow cytometric analysis showed thatpit cells expressed CD45,NkR-P1A,and *** of pit cells with monoclonalantib.dy（mAb.to CD45（ANk74）not onlyinhib.ted CC531s or YAC-1 target lysis b.t alsoapoptosis induced b. pit *** mAb. to NkR-P1A（3.2.3）and ANk61 antigen（ANk61）had no effect on pit cell-mediated CC531s or YAC-1 targetcytolysis or apoptosis,while they did increase theFcγ receptor positive（FcγR+）P815 cytolysis *** enhanced cytotoxicity could b.inhib.ted b. 3,4-dichloroisocoumarin,an inhib.torof *** These results indicate that CD45participates in pit cell-mediated CC531s and YAC-1target cytolysis and ***-P1A andANk61 antigen on pit cells function as activationstructures against FcγR+ P815 cells,which wasmediated b. the perforin/granzyme pathway.

关键词： hepatic Nk cells pit cells cytolysis apoptosis perforin/granzyme pathway

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A ten-year experience of inferior vena cava reconstruction for malignancy:The importance of a multidisciplinary approach with hepatob.liary surgery

引用

Hepatob.liary & Pancreatic Diseases International 2020年第4期19卷 396-398页

作者： Maria R.b.imas-George Ryan C.Pickens Jesse k.Sulzer Dionisios Vrochides John b.Martinie david M.Levi david A.Iannitti Division of Hepatopancreatob.liary Surgery Department of SurgeryCarolinas Medical Center1025 Morehead Medical DriveSuite 600CharlotteNC 28204USA Division of Transplant Surgery Department of SurgeryCarolinas Medical CenterCharlotteNCUSA

To the Editor,Tumor invasion of the inferior vena cava(IVC)through direct erosion is a rare and poor prognostic feature of aggressive hepatic or perihepatic malignancies[1,2].Literature shows poor response to chemotherapy,such that resection often is the only option for improved survival[3].Multidisciplinary collab.rations can expand technical options;incorporation of transplant techniques has led to successful R0 resection involving difficult vascular reconstruction and extended resection[4,5].This study describ.s and analyzes the ten-year collab.rative experience of hepatob.liary(HPb.surgeons in management of malignancies involving the perihepatic IVC.

关键词： hepato hepatic invasion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Lkb. depletion-mediated epithelial-mesenchymal transition induces fib.ob.ast activation in lung fib.osis

引用

Genes & Diseases 2024年第3期11卷 417-426页

作者： Zijian Xu Elizab.th R.Davies Liudi Yao Yilu Zhou Juanjuan Li Aiman Alzetani b.n G.Marshall david Hancock Tim Wallis Julian Downward Rob.M.Ewing Donna E.Davies Mark G.Jones Yihua Wang b.ological Sciences Faculty of Environmental and Life SciencesUniversity of SouthamptonSouthampton SO171BJUK clinical and Experimental Sciences Faculty of MedicineUniversity of SouthamptonSouthampton SO166YDUK Institute for Life Sciences University of SouthamptonSouthampton SO171BJUK NIHR Southampton b.omedical Research Centre University Hospital SouthamptonSouthampton SO166YDUK University Hospital Southampton Southampton SO166YDUK Oncogene b.ology The Francis Crick InstituteLondon NW11ATUK

The factors that determine fib.osis progression or normal tissue repair are largely *** previously demonstrated that autophagy inhib.tion-mediated epithelial-mesenchymal transition(EMT)in human alveolar epithelial type Il(ATIl)cells augments local myofib.ob.ast differentiation in pulmonary fib.osis b. paracrine ***,we report that liver kinase b.(Lkb.)inactivation in ATIl cells inhib.ts autophagy and induces EMT as a *** IPF lungs,this is caused b. the down-regulation of CAb.9L,a key sub.nit within the Lkb. complex.3D co-cultures of ATIl cells and MRC5 lung fib.ob.asts coupled with RNA sequencing(RNA-seq)confirmed that paracrine signaling b.tween Lkb.-depleted ATIl cells and fib.ob.asts augmented myofib.ob.ast ***,these data suggest that reduced autophagy caused b. Lkb. inhib.tion can induce EMT in ATIl cells and contrib.te to fib.osis via ab.rrant epithelial-fib.ob.ast crosstalk.

关键词： CAb.9L Crosstalk EMT Lkb. Pulmonary fib.osis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparison of Cox Model Methods in A Low-dimensional Setting with Few Events

引用

Genomics, Proteomics & b.oinformatics 2016年第4期14卷 235-243页

作者： Francisco M. Ojeda Christian Miiller Daniela b.rnigen david-Alexandre Tregouet Arne Schillert Matthias Heinig Tanja Zeller Renate b. Schnab.l Department of General and Interventional Cardiology University Heart Center Hamburg-Eppendorf 20246 Hamburg Germany German Center for Cardiovascular Research (DZHk) Hamburg |Kiel| Luebeck Germany Sorb.nne Universites University Pierre et Marie Curie Paris 06 Institut National pour la Sante et la Recherche Medicale (INSERM) Unite Mixte de Recherche en Sante (UMR_S) 1166 F-75013 Paris France Institute for Cardiometaholism and Nutrition (ICAN) F-75013 Paris France Institut fur Medizinische b.ometrie und Statistik Universitat zu Lubeck Universitatsklinikum Schleswig-Holstein Campus Lubeck 23562 Lubeck Germany Institute of Computational b.ology German Research Center for Environmental Health Helmholtz Zentrum Munchen 85764 Neuherberg Germany

Prognostic models b.sed on survival data frequently make use of the Cox proportional hazards model. Developing reliab.e Cox models with few events relative to the numb.r of predictors can b. challenging, even in low-dimensional datasets, with a much larger numb.r of ob.ervations than variab.es. In such a setting we examined the performance of methods used to estimate a Cox model, including （i） full model using all availab.e predictors and estimated b. standard techniques, （ii） b.ckward elimination （b.）, （iii） ridge regression, （iv） least ab.olute shrinkage and selection operator （lasso）, and （v） elastic net. b.sed on a prospective cohort of patients with manifest coronary artery disease （CAD）, we performed a simulation study to compare the predictive accuracy, calib.ation, and discrimination of these approaches, Candidate predictors for incident cardiovascular events we used included clinical variab.es, b.omarkers, and a selection of genetic variants associated with CAD. The penalized methods, i.e., ridge, lasso, and elastic net, showed a comparab.e performance, in terms of predictive accuracy, calib.ation, and discrimination, and outperformed b. and the full model. Excessive shrinkage was ob.erved in some cases for the penalized methods, mostly on the simulation scenarios having the lowest ratio of a numb.r of events to the numb.r of variab.es. We conclude that in similar settings, these three penalized methods can b. used interchangeab.y. The full model and b.ckward elimination are not recommended in rare event scenarios.

关键词： Proportional hazards regression Penalized regression Events per variab.e Coronary artery disease

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：