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   5000740篇
  免费   387420篇
  国内免费   15869篇
耳鼻咽喉   70960篇
儿科学   162202篇
妇产科学   134041篇
基础医学   747652篇
口腔科学   139589篇
临床医学   455817篇
内科学   912741篇
皮肤病学   120293篇
神经病学   416443篇
特种医学   196468篇
外国民族医学   1079篇
外科学   755399篇
综合类   136964篇
现状与发展   24篇
一般理论   2783篇
预防医学   412520篇
眼科学   118558篇
药学   357841篇
  27篇
中国医学   13332篇
肿瘤学   249296篇
  2021年   57326篇
  2019年   59903篇
  2018年   77308篇
  2017年   59247篇
  2016年   65924篇
  2015年   78415篇
  2014年   112962篇
  2013年   179432篇
  2012年   142568篇
  2011年   150663篇
  2010年   132560篇
  2009年   132317篇
  2008年   136450篇
  2007年   146788篇
  2006年   154478篇
  2005年   148706篇
  2004年   149202篇
  2003年   139403篇
  2002年   128886篇
  2001年   194734篇
  2000年   190896篇
  1999年   172310篇
  1998年   75494篇
  1997年   70199篇
  1996年   68178篇
  1995年   63526篇
  1994年   57552篇
  1993年   53251篇
  1992年   126827篇
  1991年   121975篇
  1990年   118147篇
  1989年   115045篇
  1988年   106376篇
  1987年   104161篇
  1986年   98590篇
  1985年   96035篇
  1984年   77666篇
  1983年   68788篇
  1982年   51648篇
  1981年   47619篇
  1980年   44692篇
  1979年   68358篇
  1978年   53286篇
  1977年   47126篇
  1976年   43709篇
  1975年   45202篇
  1974年   50088篇
  1973年   47950篇
  1972年   45316篇
  1971年   41901篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among...  相似文献   
73.
European Surgery - Treatment of pilonidal sinus disease (PSD) requires a tailored approach. A national guideline was published in 2014. The current status of surgical PSD therapy...  相似文献   
74.
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric plasma equilibrium problem. The proposed method, obtained from an improvement of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium problem in unbounded domains by discretizing only the plasma region; the external conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github. om/matteobonotto/ FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against experimental data from RFX-mod device, and numerical equilibria of an ITER-like device.  相似文献   
75.
76.
77.
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   
78.
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