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   192569篇
  免费   33378篇
  国内免费   2618篇
耳鼻咽喉   5513篇
儿科学   6547篇
妇产科学   3557篇
基础医学   8759篇
口腔科学   2380篇
临床医学   30806篇
内科学   56158篇
皮肤病学   8222篇
神经病学   19168篇
特种医学   7725篇
外科学   46254篇
综合类   401篇
现状与发展   72篇
一般理论   19篇
预防医学   10168篇
眼科学   4063篇
药学   3607篇
  1篇
中国医学   91篇
肿瘤学   15054篇
  2024年   735篇
  2023年   5185篇
  2022年   2126篇
  2021年   4737篇
  2020年   6928篇
  2019年   3545篇
  2018年   8927篇
  2017年   8393篇
  2016年   9584篇
  2015年   9796篇
  2014年   17372篇
  2013年   18000篇
  2012年   9182篇
  2011年   9169篇
  2010年   12139篇
  2009年   15871篇
  2008年   8702篇
  2007年   6845篇
  2006年   9022篇
  2005年   6285篇
  2004年   5132篇
  2003年   3878篇
  2002年   3744篇
  2001年   3974篇
  2000年   3127篇
  1999年   3399篇
  1998年   3902篇
  1997年   3658篇
  1996年   3536篇
  1995年   3360篇
  1994年   2076篇
  1993年   1673篇
  1992年   1444篇
  1991年   1472篇
  1990年   1109篇
  1989年   1211篇
  1988年   1044篇
  1987年   879篇
  1986年   910篇
  1985年   739篇
  1984年   579篇
  1983年   536篇
  1982年   548篇
  1981年   422篇
  1980年   379篇
  1979年   315篇
  1978年   339篇
  1977年   408篇
  1975年   283篇
  1972年   309篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
95.
96.
BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation.  相似文献   
97.
98.
99.
100.
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   
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