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   31284篇
  免费   2507篇
  国内免费   194篇
耳鼻咽喉   372篇
儿科学   824篇
妇产科学   650篇
基础医学   3661篇
口腔科学   1635篇
临床医学   2892篇
内科学   6705篇
皮肤病学   820篇
神经病学   1927篇
特种医学   832篇
外国民族医学   8篇
外科学   4529篇
综合类   820篇
一般理论   20篇
预防医学   2263篇
眼科学   1110篇
药学   2677篇
中国医学   268篇
肿瘤学   1972篇
  2024年   39篇
  2023年   370篇
  2022年   1036篇
  2021年   1675篇
  2020年   1105篇
  2019年   1446篇
  2018年   1726篇
  2017年   1224篇
  2016年   1346篇
  2015年   1302篇
  2014年   1702篇
  2013年   2035篇
  2012年   2484篇
  2011年   2661篇
  2010年   1615篇
  2009年   1235篇
  2008年   1720篇
  2007年   1575篇
  2006年   1361篇
  2005年   1217篇
  2004年   1051篇
  2003年   872篇
  2002年   754篇
  2001年   269篇
  2000年   253篇
  1999年   233篇
  1998年   131篇
  1997年   110篇
  1996年   107篇
  1995年   99篇
  1994年   56篇
  1993年   64篇
  1992年   98篇
  1991年   71篇
  1990年   71篇
  1989年   80篇
  1988年   86篇
  1987年   73篇
  1986年   66篇
  1985年   63篇
  1984年   61篇
  1983年   39篇
  1982年   39篇
  1981年   35篇
  1980年   28篇
  1979年   36篇
  1978年   27篇
  1977年   30篇
  1975年   23篇
  1974年   23篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
A rare case of congenital lumbar hernia associated with carpus equina varus is described in a week old baby. The treatment is described with limited review of the literature.  相似文献   
32.
Despite recent advances in surgical technique using laparoscopic and robotic approaches for the management of early organ-confined prostate cancer, most contemporary reports demonstrate significant rates of erectile dysfunction comparable to standard open approaches. Controversy remains related to many of the pre-and postoperative management strategies, including agents to enhance nerve recovery, erectogenic drugs, antioxidants, vasoactive injectables, vacuum erection devices and nerve grafting procedures. Additionally, the optimal timing of these interventions and their duration, dose, frequency and outcome thresholds remain ill-defined. In our paper, we provide a comprehensive literature review involving both the basic and clinical data surrounding rehabilitative approaches.  相似文献   
33.
34.
Device-induced thrombogenesis was studied in an in vitro model using human blood circulated through an artificial ventricle. A new constant pressure filtration technique was used to detect circulating microemboli, the activated partial thromboplastin time (APTT) test was used to monitor the blood for the presence of anticoagulant activity of heparin, and hemolysis was quantified by measuring the plasma free hemoglobin level. Circulation of blood through a 20-ml stroke volume pneumatically driven ventricle for 6-9 h resulted in a significant reduction of APTT, indicating the loss of the anticoagulant effect of heparin. Microemboli concentration was minimal until the APTT decreased below 125 s, at which time the microemboli concentration increased rapidly. This was presumed to be due to the formation of thrombi following a decrease in heparin activity. A significant increase in hemolysis was also noted when blood was pumped. None of these changes was noted in the nonpumped control blood. Spontaneous loss of heparin activity in blood circulated by a pneumatically driven pump may have clinical implications and may help understanding of the problems associated with device-induced thrombogenesis.  相似文献   
35.
36.
37.
38.
A consecutive series of 47 hospitalized cases of Guillain-Barré syndrome seen over a 10-year period was analysed with respect to: (1) age and sex; (2) antecedent events and seasonal distribution; (3) patterns of clinical presentation; (4) CSF and neurophysiological findings; (5) results of treatment with plasma exchange; and (6) outcome. Twenty-two were children, 20 middle-aged and 5 aged; 37 were male and 10 were female. The most frequent antecedent event was upper respiratory tract infections; a seasonal peak incidence was found in winter. Clinical, CSF and neurophysiological findings concurred with those in the Western literature; 79% of the cases were severe. Plasma exchange performed within the first 2 weeks of onset benefitted in the short-term outcome, i.e. improvement by 1 grade at 4 weeks, but the long-term benefit, i.e. the ability to regain independent locomotion, was questionable. Plasma exchange helped in curtailing the time to walking unaided but had no benefit on the duration of artificial ventilation. Factors associated with an adverse outcome were: age over 15 years, severity of motor electrodiagnostic findings (especially a decreased distal CMAP amplitude and EMG signs of acute denervation), requirement for ventilation and slow progression (>3 weeks) to maximum deficit. After a mean follow-up of 11 months, 55% of the patients regained independent locomotion, which is a comparatively low proportion.  相似文献   
39.
The effects of tetracaine (10–50 M) and ryanodine (0.1–10 M) were tested on the slow outward K+ current (I so) and the mechanical tension of isolated frog muscle fibres in a voltage-clamp device (double mannitol-gap) connected to a mechanoelectric transducer. In the concentration range tested, both drugs induced a simultaneous inhibition of tension and current. In all cases the effect on tension was twice that on current. The tetracaine-induced current and tension blocks were fully reversible and dose-dependent. In contrast the ryanodine effects on current and tension were not reversible and did not exhibit a dose dependence except for the delay before the onset of the response, which was shortened when the concentration was raised. Linear regression analysis of the time-dependent and dose-dependent effects of both drugs indicated a strong correlation between the decreases in tension and current. It is concluded that the slow outward current is partly under the control of the Ca2+ release from sarcoplasmic reticulum during contraction.  相似文献   
40.
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