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   157267篇
  免费   31966篇
  国内免费   2411篇
耳鼻咽喉   5225篇
儿科学   5523篇
妇产科学   2532篇
基础医学   4209篇
口腔科学   1630篇
临床医学   27389篇
内科学   48725篇
皮肤病学   7524篇
神经病学   15344篇
特种医学   6524篇
外科学   41802篇
综合类   382篇
现状与发展   72篇
一般理论   7篇
预防医学   7767篇
眼科学   3398篇
药学   1487篇
中国医学   10篇
肿瘤学   12094篇
  2024年   685篇
  2023年   4804篇
  2022年   1220篇
  2021年   3154篇
  2020年   6056篇
  2019年   2219篇
  2018年   7442篇
  2017年   7359篇
  2016年   8439篇
  2015年   8459篇
  2014年   15561篇
  2013年   15727篇
  2012年   5642篇
  2011年   5705篇
  2010年   10444篇
  2009年   14332篇
  2008年   5960篇
  2007年   4163篇
  2006年   6658篇
  2005年   3975篇
  2004年   3217篇
  2003年   2191篇
  2002年   2247篇
  2001年   4070篇
  2000年   3261篇
  1999年   3442篇
  1998年   3751篇
  1997年   3529篇
  1996年   3444篇
  1995年   3273篇
  1994年   2013篇
  1993年   1631篇
  1992年   1592篇
  1991年   1614篇
  1990年   1264篇
  1989年   1352篇
  1988年   1191篇
  1987年   1024篇
  1986年   1081篇
  1985年   888篇
  1984年   680篇
  1983年   667篇
  1982年   609篇
  1981年   497篇
  1980年   431篇
  1979年   448篇
  1978年   462篇
  1977年   492篇
  1975年   377篇
  1972年   369篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
65.
66.
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   
67.
68.
69.
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   
70.
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   
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