首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   188004篇
  免费   32820篇
  国内免费   2599篇
耳鼻咽喉   5634篇
儿科学   6046篇
妇产科学   2746篇
基础医学   7872篇
口腔科学   2445篇
临床医学   29288篇
内科学   56335篇
皮肤病学   8003篇
神经病学   17519篇
特种医学   7873篇
外科学   46963篇
综合类   452篇
现状与发展   72篇
预防医学   8292篇
眼科学   4064篇
药学   4073篇
中国医学   100篇
肿瘤学   15646篇
  2024年   697篇
  2023年   4940篇
  2022年   1536篇
  2021年   3667篇
  2020年   6281篇
  2019年   2567篇
  2018年   7910篇
  2017年   7755篇
  2016年   8945篇
  2015年   8975篇
  2014年   16235篇
  2013年   16617篇
  2012年   7000篇
  2011年   7203篇
  2010年   11308篇
  2009年   15088篇
  2008年   7356篇
  2007年   5719篇
  2006年   8184篇
  2005年   5607篇
  2004年   4868篇
  2003年   3825篇
  2002年   3944篇
  2001年   5064篇
  2000年   4432篇
  1999年   4451篇
  1998年   4166篇
  1997年   3860篇
  1996年   3757篇
  1995年   3560篇
  1994年   2276篇
  1993年   1903篇
  1992年   2232篇
  1991年   2168篇
  1990年   1827篇
  1989年   1990篇
  1988年   1769篇
  1987年   1518篇
  1986年   1509篇
  1985年   1307篇
  1984年   1013篇
  1983年   863篇
  1982年   717篇
  1981年   565篇
  1980年   547篇
  1979年   615篇
  1978年   570篇
  1977年   583篇
  1975年   410篇
  1972年   447篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
OBJECTIVE: To obtain consensus among a panel of experts on performance measures useful for evaluating the quality of hospital-based domestic violence (DV) programs. METHODS: The Delphi process of consensus development was used with a panel of 18 experts including DV researchers, program planners, and advocates. Three rounds were conducted over a period of six months, with each round involving the completion of a written questionnaire. Panelists were instructed to concentrate on structure and process measures of DV program performance. Health outcome measures were not considered. During each round, panelists rated (scale of 1-5) their level of agreement with each measure, in terms of the measure's usefulness for evaluating hospital-based DV programs. Data were entered into SPSS on a personal computer and frequency distributions, measures of central tendency, and variance were computed for each measure. Consensus development was defined as a reduction in the item-specific variance from one round to the next. RESULTS: A total of 37 performance measures were agreed upon. These measures fell within nine different domains of DV program activities, including: Policies and Procedures, Hospital Physical Environment, Hospital Cultural Environment, Training of Providers, Screening and Safety Assessment, Documentation, Intervention Services, Evaluation Activities, and Collaboration. CONCLUSIONS: A number of measures have been identified as useful for evaluating hospital-based DV programs. Use of these measures should assist researchers, program planners, and administrators in assessing the quality of hospital-based DV programs.  相似文献   
74.
This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference.  相似文献   
75.
76.
77.
An attempt was made to explore the quantitative relationship between the intestinal absorption data obtained from in vivo studies and in situ perfusion studies. The time course of the fraction remaining to be absorbed of L-glucose, erythritol, and urea in the small intestine following the intrajejunal administration to rats was described by a one-compartment model. Thus derived first-order intestinal absorption rate constants (ka) obtained from the in vivo studies in rats were compared with the membrane permeability clearances (CLa,m) estimated in a single-pass perfusion system. Not only were ka and CLa,m in the same increasing order of L-glucose less than erythritol less than urea, but also the operational luminal volumes given as CLa,m/ka were in agreement with the in vivo luminal volume of jejunum estimated by an inulin dilution method. This result suggests that the in vivo intestinal absorption rate (or ka) can be correlated with the intestinal membrane permeability (or CLa,m) by taking the in vivo luminal volume into account.  相似文献   
78.
This study evaluates the potential for endothelial seeding of a collagen-impregnated Dacron graft with or without surface modifiers (fibronectin, heparin) to attach and retain these cells during flow. Human umbilical endothelial cells were harvested, cultured, labeled with Indium111-oxine and seeded onto 30 mm X 4 mm diameter grafts. Six graft surfaces were studied: 1) a collagen-impregnated Dacron graft, HemashieldR (C); 2) C + fibronectin (C + F); 3) C + heparin (C + H); 4) C + F + H; 5) HytrelR + F (Hyt + F); and 6) Hyt + F + H. Radioactive loss determined the percentage attachment and then percentage retention of labeled inoculum after a one-hour in vitro perfusion. Scanning electron and light microscopy demonstrated the endothelium on the graft surface following perfusion. Fibronectin-coated grafts had a significantly higher percentage attachment than those without fibronectin (ANOVA, P less than 0.05). However, the percentage retention following perfusion was similar for all Dacron grafts and statistically inferior to the HytrelR grafts studied (ANOVA, P less than 0.05). SEM evaluation of the C + F + H graft surface was qualitatively the most impressive Dacron surface for seeding, yet was inferior to the HytrelR graft. We conclude that fibronectin benefits the initial attachment of endothelium to collagen-coated Dacron rivaling the HytrelR surface. Fibronectin does not improve percentage retention of the HemashieldR surface during perfusion, therefore, some of its initial benefit is lost.  相似文献   
79.
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号