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   15862篇
  免费   1508篇
  国内免费   33篇
耳鼻咽喉   164篇
儿科学   482篇
妇产科学   518篇
基础医学   2180篇
口腔科学   233篇
临床医学   2277篇
内科学   2870篇
皮肤病学   262篇
神经病学   1575篇
特种医学   417篇
外国民族医学   1篇
外科学   1881篇
综合类   315篇
一般理论   12篇
预防医学   1820篇
眼科学   345篇
药学   1037篇
中国医学   19篇
肿瘤学   995篇
  2022年   99篇
  2021年   271篇
  2020年   182篇
  2019年   260篇
  2018年   361篇
  2017年   284篇
  2016年   293篇
  2015年   311篇
  2014年   471篇
  2013年   662篇
  2012年   878篇
  2011年   865篇
  2010年   483篇
  2009年   464篇
  2008年   810篇
  2007年   788篇
  2006年   817篇
  2005年   822篇
  2004年   748篇
  2003年   694篇
  2002年   654篇
  2001年   378篇
  2000年   361篇
  1999年   339篇
  1998年   169篇
  1997年   158篇
  1996年   125篇
  1995年   125篇
  1994年   120篇
  1993年   99篇
  1992年   254篇
  1991年   252篇
  1990年   244篇
  1989年   206篇
  1988年   232篇
  1987年   221篇
  1986年   234篇
  1985年   203篇
  1984年   178篇
  1983年   177篇
  1982年   128篇
  1981年   127篇
  1980年   105篇
  1979年   184篇
  1978年   133篇
  1977年   98篇
  1976年   121篇
  1975年   119篇
  1974年   131篇
  1973年   95篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
51.
Summary Urinary output of endogenous monoamine oxidase (MAO) inhibitory activity, was significantly raised in serial samples collected across a migraine attack compared with collections during attack-free periods and in healthy controls, which did not differ from each other. There was a highly significant correlation in output between isatin, a major fraction of the MAO inhibitory activity, and output of the MAO inhibitory activity itself. However, although there was a tendency towards increased isatin excretion during migraine attacks, it failed to reach statistical significance.  相似文献   
52.
A patient of 12 suffering from aneurysmal cyst of the ischium was studied with traditional radiology, computed tomography (CT) and magnetic resonance imaging (MRI). The advantages of MRI in the study of this pathology compared to traditional radiography and CT are assessed. It was shown that the CT and MRI techniques are superior to standard X-ray examinations in anatomic definition and in evaluating the lesions's relationships with neighbouring structures and, in particular, that MRI is superior to CT in extension.  相似文献   
53.
A 23-year-old man sustained an isolated popliteus tendon rupture while pushing a car. The diagnosis was established with the use of arthroscopy, electromyography, and Cybex testing. After the patient failed to respond to conservative therapy, the tendon rupture was surgically repaired. The patient had an uneventful recovery and returned to his preinjury level of athletic activity. Although popliteus tendon tenosynovitis as well as injury to the popliteus in association with other ligamentous knee injuries has been described, neither an isolated popliteus tendon rupture nor an arthroscopic evaluation of a popliteus tendon rupture has been reported.  相似文献   
54.
55.
A method is described for the chemical measurement of calcium oxalate and phosphate crystal formation in urine. The crystals were centrifuged, washed and the oxalate measured by an immobilised oxalate oxidase technique and the phosphate by a standard centrifugal analyser procedure. The methods proved precise and recoveries were good. Calcium oxalate crystal formation after evaporation is time-dependent and this parameter must therefore be standardised. Values for normal urinary calcium oxalate crystal concentration after concentration are given.  相似文献   
56.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein levels increase in particulate fractions in association with cell death in HEK293 cells, S49 cells, primary thymocytes, PC12 cells, and primary cerebral cortical neuronal cultures. Subcellular fractionation and immunocytochemistry reveal that this increase primarily reflects nuclear translocation. Nuclear GAPDH is tightly bound, resisting extraction by DNase or salt treatment. Treating primary thymocytes, PC12 cells, and primary cortical neurons with antisense but not sense oligonucleotides to GAPDH prevents cell death. Because cell-death-associated nuclear translocation of GAPDH and antisense protection occur in multiple neuronal and nonneuronal systems, we propose that GAPDH is a general mediator of cell death and uses nuclear translocation as a signaling mechanism.  相似文献   
57.
58.
59.
BACKGROUND: Abnormalities in the limbic-hypothalamic-pituitary-adrenal (LHPA) axis have been implicated in the pathogenesis of obsessive-compulsive disorder (OCD). To our knowledge, however, no prior study has measured pituitary gland volume in OCD. METHODS: Volumetric magnetic resonance imaging studies were conducted in 31 psychotropic drug-na?ve children (10 boys, 21 girls) aged 8-17 years and 31 case-matched healthy comparison subjects. RESULTS: Pituitary volume was significantly smaller in patients with OCD as compared with healthy control subjects (11% smaller). Smaller pituitary volume in patients with OCD was associated with increased compulsive but not obsessive symptom severity. Boys with OCD had smaller pituitary gland volumes compared with control boys (20% smaller). No significant differences in pituitary volume were observed between girls with OCD and control girls. Boys with OCD had significantly smaller pituitary volumes than girls with OCD (31% smaller), whereas control boys also had smaller pituitary gland volumes compared with control girls (21% smaller). CONCLUSIONS: These findings provide new evidence of reduced pituitary volume in pediatric OCD that seems to be more prominent in male patients. The observed alterations in pituitary volume are consistent with neuroendocrine studies that have reported abnormalities in the LHPA axis in OCD.  相似文献   
60.
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