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   1660篇
  免费   241篇
  国内免费   17篇
耳鼻咽喉   16篇
儿科学   69篇
妇产科学   15篇
基础医学   167篇
口腔科学   16篇
临床医学   249篇
内科学   361篇
皮肤病学   30篇
神经病学   136篇
特种医学   88篇
外科学   308篇
综合类   57篇
现状与发展   20篇
预防医学   178篇
眼科学   45篇
药学   79篇
中国医学   2篇
肿瘤学   82篇
  2023年   42篇
  2021年   36篇
  2020年   27篇
  2019年   18篇
  2018年   64篇
  2017年   50篇
  2016年   35篇
  2015年   48篇
  2014年   53篇
  2013年   92篇
  2012年   53篇
  2011年   68篇
  2010年   68篇
  2009年   80篇
  2008年   67篇
  2007年   59篇
  2006年   61篇
  2005年   40篇
  2004年   36篇
  2003年   29篇
  2002年   40篇
  2001年   44篇
  2000年   32篇
  1999年   35篇
  1998年   34篇
  1997年   42篇
  1996年   49篇
  1995年   40篇
  1994年   24篇
  1993年   27篇
  1992年   26篇
  1991年   26篇
  1990年   31篇
  1989年   28篇
  1988年   35篇
  1987年   29篇
  1986年   21篇
  1985年   24篇
  1984年   15篇
  1983年   12篇
  1982年   13篇
  1981年   10篇
  1980年   9篇
  1979年   14篇
  1978年   16篇
  1977年   15篇
  1976年   16篇
  1975年   12篇
  1971年   15篇
  1968年   11篇
排序方式: 共有1918条查询结果,搜索用时 62 毫秒
1.
2.
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   
3.

Background  

The fibromyalgia syndrome (FMS) is suggested to be a manifestation of depression or affective spectrum disorder. We measured the cognitive style of patients with FMS to assess personality styles in 44 patients with fibromyalgia syndrome (FMS) by comparing them with 43 patients with major depressive disorder (MDD) and 41 healthy controls (HC).  相似文献   
4.
5.
6.
B G Stiles 《Toxicon》1991,29(4-5):503-510
A non-radioactive assay was developed for detecting the binding of postsynaptic neurotoxins to acetylcholine receptor (AchR) from Torpedo californica. Enzyme linked immunosorbent assay (ELISA) wells coated with long or short chain neurotoxins specifically bound to purified AchR while crotamine or two different cardiotoxins did not. Bound receptor was detected by antibody against AchR. Specificity was determined by dose-response experiments and competition studies using carbamylcholine chloride, acetylcholine chloride, or Naja naja atra cobrotoxin mixed with receptor.  相似文献   
7.
8.
A randomized controlled trial of sedation in the critically ill   总被引:2,自引:0,他引:2  
A randomized controlled trial comparing: a) a combination of oral chloral hydrate and promethazine to b) a continuous intravenous midazolam infusion, for maintenance sedation in critically ill children, was carried out. The level of sedation was assessed four hourly using a specifically devized sedation scale. Forty-four children entered the study of whom two were subsequently excluded. The number of satisfactory assessments (desired and actual levels of sedation equal) was significantly greater in the chloral hydrate and promethazine group (Chi-squared P <0.01; confidence intervals of the difference 0.06 to 0.20). The number of assessments at level 5 on the sedation scale (patient restless/distressed) was significantly greater in the midazolam group (Chi-squared P <0.05). The total number of satisfactory assessments in the two groups were only 61 and 48% respectively, suggesting that sedation can be considerably improved. Chloral hydrate and promethazine are more effective than midazolam as maintenance sedation in critically ill children. It is possible to prospectively study the efficacy of sedative drugs in critically ill children.  相似文献   
9.
10.
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