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   5457477篇
  免费   425041篇
  国内免费   16714篇
耳鼻咽喉   78241篇
儿科学   173037篇
妇产科学   145689篇
基础医学   805817篇
口腔科学   155652篇
临床医学   504920篇
内科学   997680篇
皮肤病学   125878篇
神经病学   456592篇
特种医学   213835篇
外国民族医学   1455篇
外科学   815936篇
综合类   153438篇
现状与发展   24篇
一般理论   3043篇
预防医学   459916篇
眼科学   130912篇
药学   393161篇
  28篇
中国医学   14113篇
肿瘤学   269865篇
  2021年   57272篇
  2019年   59725篇
  2018年   77453篇
  2017年   59444篇
  2016年   66276篇
  2015年   78188篇
  2014年   113035篇
  2013年   178931篇
  2012年   156206篇
  2011年   166521篇
  2010年   135296篇
  2009年   134136篇
  2008年   151812篇
  2007年   163677篇
  2006年   170224篇
  2005年   164375篇
  2004年   164693篇
  2003年   154151篇
  2002年   143641篇
  2001年   219553篇
  2000年   217959篇
  1999年   194076篇
  1998年   79256篇
  1997年   73107篇
  1996年   70918篇
  1995年   66581篇
  1994年   60585篇
  1993年   55947篇
  1992年   145353篇
  1991年   139874篇
  1990年   134577篇
  1989年   130636篇
  1988年   120916篇
  1987年   119002篇
  1986年   112573篇
  1985年   109413篇
  1984年   87366篇
  1983年   76680篇
  1982年   55192篇
  1981年   50943篇
  1980年   47675篇
  1979年   78474篇
  1978年   60140篇
  1977年   52365篇
  1976年   49026篇
  1975年   49971篇
  1974年   57577篇
  1973年   55235篇
  1972年   51996篇
  1971年   47951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