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   4353250篇
  免费   349798篇
  国内免费   14729篇
耳鼻咽喉   60378篇
儿科学   139595篇
妇产科学   114352篇
基础医学   667424篇
口腔科学   118138篇
临床医学   397490篇
内科学   791719篇
皮肤病学   108027篇
神经病学   368859篇
特种医学   169567篇
外国民族医学   753篇
外科学   656563篇
综合类   121306篇
现状与发展   25篇
一般理论   2617篇
预防医学   361169篇
眼科学   101002篇
药学   307974篇
  26篇
中国医学   11971篇
肿瘤学   218822篇
  2021年   56411篇
  2020年   35953篇
  2019年   59034篇
  2018年   74660篇
  2017年   57129篇
  2016年   63251篇
  2015年   76237篇
  2014年   110529篇
  2013年   176085篇
  2012年   124830篇
  2011年   129536篇
  2010年   126155篇
  2009年   127813篇
  2008年   115615篇
  2007年   122889篇
  2006年   131601篇
  2005年   125707篇
  2004年   126942篇
  2003年   117146篇
  2002年   106365篇
  2001年   166964篇
  2000年   162020篇
  1999年   148698篇
  1998年   71690篇
  1997年   67629篇
  1996年   65644篇
  1995年   61066篇
  1994年   54977篇
  1993年   51025篇
  1992年   106620篇
  1991年   101386篇
  1990年   97240篇
  1989年   94810篇
  1988年   87139篇
  1987年   85306篇
  1986年   80192篇
  1985年   78350篇
  1984年   65397篇
  1983年   58197篇
  1982年   47188篇
  1981年   43861篇
  1980年   41074篇
  1979年   55100篇
  1978年   44753篇
  1977年   39979篇
  1976年   36838篇
  1975年   36804篇
  1974年   39608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 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