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   240940篇
  免费   6867篇
  国内免费   603篇
耳鼻咽喉   3488篇
儿科学   8574篇
妇产科学   6895篇
基础医学   31449篇
口腔科学   9132篇
临床医学   19031篇
内科学   44930篇
皮肤病学   5704篇
神经病学   15843篇
特种医学   11669篇
外国民族医学   98篇
外科学   34534篇
综合类   1352篇
一般理论   15篇
预防医学   20769篇
眼科学   5269篇
药学   16758篇
  2篇
中国医学   503篇
肿瘤学   12395篇
  2021年   1958篇
  2020年   1185篇
  2019年   1660篇
  2018年   5378篇
  2017年   5073篇
  2016年   4422篇
  2015年   6085篇
  2014年   6127篇
  2013年   5833篇
  2012年   13440篇
  2011年   8877篇
  2010年   4361篇
  2009年   5495篇
  2008年   5155篇
  2007年   5832篇
  2006年   5798篇
  2005年   13629篇
  2004年   14983篇
  2003年   10204篇
  2002年   5293篇
  2001年   5070篇
  2000年   2487篇
  1999年   6364篇
  1992年   6997篇
  1991年   7220篇
  1990年   7461篇
  1989年   7034篇
  1988年   6538篇
  1987年   6308篇
  1986年   6029篇
  1985年   5325篇
  1984年   3688篇
  1983年   2976篇
  1982年   1055篇
  1980年   893篇
  1979年   3869篇
  1978年   2398篇
  1977年   1817篇
  1976年   1583篇
  1975年   2503篇
  1974年   3130篇
  1973年   2756篇
  1972年   2788篇
  1971年   2775篇
  1970年   2584篇
  1969年   2482篇
  1968年   2248篇
  1967年   2187篇
  1966年   1913篇
  1965年   1144篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  相似文献   
4.
5.
6.
7.
8.
9.
10.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  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