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   5832007篇
  免费   449907篇
  国内免费   17375篇
耳鼻咽喉   84229篇
儿科学   185668篇
妇产科学   156175篇
基础医学   852612篇
口腔科学   169034篇
临床医学   543726篇
内科学   1064215篇
皮肤病学   132330篇
神经病学   485311篇
特种医学   228516篇
外国民族医学   1640篇
外科学   868519篇
综合类   165930篇
现状与发展   24篇
一般理论   3197篇
预防医学   494839篇
眼科学   140874篇
药学   421136篇
  25篇
中国医学   14830篇
肿瘤学   286459篇
  2021年   57949篇
  2019年   60202篇
  2018年   78943篇
  2017年   60286篇
  2016年   67303篇
  2015年   78844篇
  2014年   113901篇
  2013年   179979篇
  2012年   167695篇
  2011年   180716篇
  2010年   139311篇
  2009年   136655篇
  2008年   165108篇
  2007年   178910篇
  2006年   184242篇
  2005年   178652篇
  2004年   178614篇
  2003年   167619篇
  2002年   156516篇
  2001年   236843篇
  2000年   236363篇
  1999年   208511篇
  1998年   82162篇
  1997年   75006篇
  1996年   72850篇
  1995年   68621篇
  1994年   62617篇
  1993年   57860篇
  1992年   157666篇
  1991年   152409篇
  1990年   147110篇
  1989年   142489篇
  1988年   131903篇
  1987年   129945篇
  1986年   123047篇
  1985年   119670篇
  1984年   94661篇
  1983年   82828篇
  1982年   57831篇
  1981年   53233篇
  1979年   86181篇
  1978年   65300篇
  1977年   56514篇
  1976年   53062篇
  1975年   54699篇
  1974年   63786篇
  1973年   61252篇
  1972年   57779篇
  1971年   53442篇
  1970年   50004篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
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   
83.
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   
84.
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   
85.
86.
87.
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   
88.
89.
90.
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