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   6213篇
  免费   420篇
  国内免费   6篇
耳鼻咽喉   56篇
儿科学   162篇
妇产科学   104篇
基础医学   807篇
口腔科学   120篇
临床医学   532篇
内科学   1293篇
皮肤病学   68篇
神经病学   812篇
特种医学   189篇
外科学   755篇
综合类   69篇
预防医学   637篇
眼科学   165篇
药学   422篇
中国医学   10篇
肿瘤学   438篇
  2022年   54篇
  2021年   108篇
  2020年   82篇
  2019年   120篇
  2018年   127篇
  2017年   92篇
  2016年   98篇
  2015年   119篇
  2014年   165篇
  2013年   241篇
  2012年   316篇
  2011年   308篇
  2010年   170篇
  2009年   152篇
  2008年   303篇
  2007年   286篇
  2006年   300篇
  2005年   284篇
  2004年   264篇
  2003年   244篇
  2002年   219篇
  2001年   188篇
  2000年   173篇
  1999年   144篇
  1998年   68篇
  1997年   54篇
  1996年   51篇
  1995年   51篇
  1994年   64篇
  1993年   56篇
  1992年   117篇
  1991年   98篇
  1990年   91篇
  1989年   102篇
  1988年   83篇
  1987年   90篇
  1986年   97篇
  1985年   82篇
  1984年   62篇
  1983年   70篇
  1982年   54篇
  1981年   46篇
  1979年   73篇
  1978年   48篇
  1977年   43篇
  1976年   53篇
  1975年   39篇
  1974年   49篇
  1973年   42篇
  1972年   41篇
排序方式: 共有6639条查询结果,搜索用时 8 毫秒
1.
2.
3.
4.
5.
6.
7.
Piroximone (MDL 19,205), a new imidazolone derivative, was given intravenously to 14 patients with congestive heart failure (NYHA class II-III), while under constant daily doses of digitalis and diuretics. In the first 3 patients, we determined the dose safely eliciting a favorable hemodynamic response. The subsequent 11 patients received 1 mg/kg of piroximone intravenously, and the hemodynamic effects were compared with those of sodium nitroprusside (SN) at a dose-lowering mean blood pressure by 10-20 mm Hg. Piroximone increased heart rate (13.2 +/- 2.0 beats/min, mean +/- SEM) and lowered mean arterial pressure (9 +/- 2.3 mm Hg). Both agents reduced similarly wedge pressure (6.5 +/- 2.9 and 9 +/- 2.9 mm Hg, respectively, for SN and piroximone) and total peripheral resistance. Cardiac index was increased less by SN (15%) than piroximone (48%) (p less than 0.001), and stroke work index significantly enhanced only by piroximone (p less than 0.001). The changes in loading conditions induced by the two agents being similar, it is likely that piroximone not only acts by peripheral vasodilation, but also possesses positive inotropic properties. Myocardial oxygen demand, assessed indirectly by tension-time index, was not affected by piroximone. Thus, piroximone appears to combine well-balanced vasodilator and inotropic properties which make this new agent potentially very useful for the management of congestive heart failure.  相似文献   
8.
Streptococcus agalactiae, known as a pathogen that causes meningitis and septicemia in neonates, emerges as an invasive organism in nonpregnant adults. This case report describes the fulminant course of a necrotizing fasciitis (NF) with streptococcal toxic shock-like syndrome (STSS) in a 76-year-old diabetic patient caused by S. agalactiae, serotype V. Chronic diseases and immunodeficiency are considered to be risk factors for the acquisition of group B streptococcal disease. Since early surgical treatment in conjunction with antimicrobial and intensive care therapy is critical for the outcome of patients with NF and/or STSS, clinicians should be aware of invasive S. agalactiae infections in adults with subcutaneous emphysema.  相似文献   
9.
Implicit learning was examined in 15 Huntington's disease (HD) patients and 15 control subjects (NC) using a semantic decision-making task. HD patients demonstrated only slightly reduced priming; like NC subjects, their decision times decreased over repeated presentations, though to a somewhat lesser degree. On explicit recognition testing, the HD group made significantly more false positive errors than did the control group, suggesting an impairment of effortful retrieval. The groups displayed equivalent retention of implicitly learned material after 6 months. The striatal neuronal loss of early Huntington's disease does not markedly affect priming or retention of primed stimuli, but may alter explicit memory judgements.  相似文献   
10.
The post-lumbar puncture syndrome (PLPS) can best be explained by prolonged spinal fluid leakage owing to delayed closure of a dural defect. Its incidence after spinal anaesthesia is much lower than after diagnostic lumbar puncture (LP). This difference could be caused by a strand of arachnoid, which might enter the needle with the outflowing cerebrospinal fluid (CSF) during diagnostic LP and upon removal of the needle be threaded back through the dura to produce prolonged CSF leakage. To find a technique that further reduces the incidence of PLPS, this hypothesis was tested by evaluating the effect that reinserting the stylet before removing the needle had on the incidence of PLPS. By reinserting the stylet to the tip of the needle, the hypothesized strand would be pushed out, thereby reducing the frequency of PLPS. Sprotte’s “atraumatic needle” (21 gauge) was used for LP. A total of 600 patients participated in the prospective study. They were randomized into two groups and questioned about their complaints every day for up to 7 days after the LP. All LPs were performed by two experienced neurologists (T.B., M.S.). In 300 patients, the stylet was reinserted to the tip of the needle; in the other 300 it was not reinserted. Whereas 49 of the 300 patients without reinsertion developed PLPS, only 15 of the 300 patients with reinsertion did. This significant difference (16.3 vs 5.0%, P < 0.005, chi square test) supports our hypothesis. On the basis of our results, we recommend reinserting the stylet before removing the needle in order to reduce the incidence of PLPS. Received: 30 September 1997 Received in revised form: 9 March 1998 Accepted: 20 March 1998  相似文献   
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