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   4383557篇
  免费   354559篇
  国内免费   18662篇
耳鼻咽喉   60652篇
儿科学   139771篇
妇产科学   114604篇
基础医学   670754篇
口腔科学   118620篇
临床医学   401691篇
内科学   793618篇
皮肤病学   108132篇
神经病学   369818篇
特种医学   170903篇
外国民族医学   773篇
外科学   659967篇
综合类   131690篇
现状与发展   34篇
一般理论   2616篇
预防医学   361261篇
眼科学   101882篇
药学   312626篇
  62篇
中国医学   15898篇
肿瘤学   221406篇
  2021年   58467篇
  2020年   37763篇
  2019年   60421篇
  2018年   75893篇
  2017年   58218篇
  2016年   64244篇
  2015年   77939篇
  2014年   112556篇
  2013年   177976篇
  2012年   127514篇
  2011年   132517篇
  2010年   128341篇
  2009年   129457篇
  2008年   117255篇
  2007年   124634篇
  2006年   133331篇
  2005年   127228篇
  2004年   128618篇
  2003年   119317篇
  2002年   108299篇
  2001年   168725篇
  2000年   163138篇
  1999年   149420篇
  1998年   72140篇
  1997年   68040篇
  1996年   65905篇
  1995年   61303篇
  1994年   55204篇
  1993年   51149篇
  1992年   106775篇
  1991年   101518篇
  1990年   97368篇
  1989年   94921篇
  1988年   87226篇
  1987年   85380篇
  1986年   80253篇
  1985年   78402篇
  1984年   65415篇
  1983年   58212篇
  1982年   47189篇
  1981年   43870篇
  1980年   41082篇
  1979年   55105篇
  1978年   44752篇
  1977年   39978篇
  1976年   36836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 31 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.
Clinical and Experimental Medicine - Recently, the use of novel targeted drugs significantly improved the overall response rate (ORR) and survival of patients with relapsed/refractory chronic...  相似文献   
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