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   4350586篇
  免费   349691篇
  国内免费   14722篇
耳鼻咽喉   60398篇
儿科学   139893篇
妇产科学   114440篇
基础医学   666739篇
口腔科学   118090篇
临床医学   397045篇
内科学   790938篇
皮肤病学   107816篇
神经病学   368378篇
特种医学   169586篇
外国民族医学   753篇
外科学   656849篇
综合类   121494篇
现状与发展   24篇
一般理论   2615篇
预防医学   360789篇
眼科学   101005篇
药学   307729篇
  27篇
中国医学   11946篇
肿瘤学   218445篇
  2021年   56132篇
  2020年   35808篇
  2019年   58788篇
  2018年   74356篇
  2017年   56976篇
  2016年   63088篇
  2015年   76056篇
  2014年   110256篇
  2013年   175799篇
  2012年   124198篇
  2011年   128908篇
  2010年   125871篇
  2009年   127602篇
  2008年   115122篇
  2007年   122376篇
  2006年   131219篇
  2005年   125281篇
  2004年   126585篇
  2003年   116798篇
  2002年   106041篇
  2001年   166946篇
  2000年   162010篇
  1999年   148687篇
  1998年   71747篇
  1997年   67647篇
  1996年   65669篇
  1995年   61072篇
  1994年   54995篇
  1993年   51048篇
  1992年   106615篇
  1991年   101387篇
  1990年   97249篇
  1989年   94831篇
  1988年   87156篇
  1987年   85317篇
  1986年   80211篇
  1985年   78357篇
  1984年   65407篇
  1983年   58204篇
  1982年   47197篇
  1981年   43869篇
  1980年   41084篇
  1979年   55109篇
  1978年   44758篇
  1977年   39991篇
  1976年   36847篇
  1975年   36812篇
  1974年   39609篇
  1973年   37749篇
  1972年   35358篇
排序方式: 共有10000条查询结果,搜索用时 31 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