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   2729篇
  免费   178篇
  国内免费   6篇
耳鼻咽喉   37篇
儿科学   76篇
妇产科学   42篇
基础医学   290篇
口腔科学   141篇
临床医学   293篇
内科学   440篇
皮肤病学   175篇
神经病学   173篇
特种医学   240篇
外科学   274篇
综合类   109篇
一般理论   1篇
预防医学   237篇
眼科学   35篇
药学   150篇
中国医学   29篇
肿瘤学   171篇
  2019年   22篇
  2018年   41篇
  2017年   31篇
  2016年   28篇
  2015年   44篇
  2014年   60篇
  2013年   111篇
  2012年   116篇
  2011年   123篇
  2010年   73篇
  2009年   72篇
  2008年   90篇
  2007年   113篇
  2006年   81篇
  2005年   77篇
  2004年   58篇
  2003年   51篇
  2002年   53篇
  2001年   67篇
  2000年   67篇
  1999年   74篇
  1998年   75篇
  1997年   68篇
  1996年   49篇
  1995年   43篇
  1994年   44篇
  1993年   40篇
  1992年   60篇
  1991年   60篇
  1990年   65篇
  1989年   64篇
  1988年   54篇
  1987年   78篇
  1986年   62篇
  1985年   61篇
  1984年   43篇
  1983年   35篇
  1981年   23篇
  1980年   25篇
  1979年   22篇
  1978年   22篇
  1977年   20篇
  1976年   29篇
  1974年   23篇
  1973年   24篇
  1972年   19篇
  1971年   20篇
  1970年   20篇
  1913年   30篇
  1912年   25篇
排序方式: 共有2913条查询结果,搜索用时 13 毫秒
41.
Ohne Zusammenfassung  相似文献   
42.
43.
44.
45.
46.
47.
48.
Acute otomastoiditis and its complications: role of CT   总被引:2,自引:0,他引:2  
Acute bacterial (suppurative) otomastoiditis responds to antibiotic treatment; radiologic study is required only when there is clinical suggestion of coalescent mastoiditis, intracranial complications, or an underlying chronic disease. Computed tomography (CT) is the method of choice for evaluating otogenic intra- or extra-cranial complications. CT scans can show stages of disease progression when infection has spread by way of soft tissue, blood, and bone pathways into the dural venous sinuses, meninges, labyrinth, facial nerves, epidural and other intracranial spaces. When there is clinical suggestion of acute coalescent mastoiditis, a CT scan of the temporal bone can confirm the presence of rarefying osteitis, coalescence of the air cells, and subperiosteal abscess.  相似文献   
49.
The purpose of this study was to evaluate the effects of bleached kraft mill effluent on selected physiological and hematological endpoints in fingerling largemouth bass (Micropterus salmoides). Fish were exposed for 35 days to surface water collected at sites up- and downstream from a pulp and paper mill treatment-effluent discharge. The condition factor, spleen somatic index, and pronephros cellularity were statistically significantly decreased in fish exposed to the downstream site, compared to the upstream site. There was also a shift from lymphocytes to neutrophils in peripheral blood of fish exposed to the downstream site. Hematocrit values and the liver somatic index were statistically significantly increased in fish in the downstream exposure. These results indicate that in-stream exposure to elemental-chlorine-free pulp and paper mill effluents produce a generalized stress response, leading to potential immunosuppression in fish.  相似文献   
50.
Lin EJ  Young D  Baer K  Herzog H  During MJ 《Epilepsia》2006,47(4):773-780
PURPOSE: Neuropeptide Y (NPY) has been shown to modulate seizure activities. To provide further understanding of the involvement of two of the most abundantly expressed NPY receptors, Y1 and Y2, we assessed the effect of Y1 and Y2 gene deletion on systemic kainic acid-induced seizures. We also examined the effect of rAAV-mediated hippocampal NPY overexpression on seizure susceptibility in these receptor knockout mice. METHODS: Recombinant adeno-associated viral vector overexpressing NPY (rAAV-NPY) or an empty vector control (rAAV-Empty) was injected into the hippocampus of adult C57BL/6-129/SvJ wild-type male mice and mice deficient of Y1 or Y2 receptors on the same background. Four weeks after vector injection, mice were subjected to systemic kainic acid-induced seizures, and the seizure behaviors were scored. RESULTS: The rAAV-mediated hippocampal overexpression of NPY led to a twofold reduction in seizures induced by systemic kainic acid in wild-type mice and Y1 receptor knockout mice but not in mice deficient of Y2 receptors. A differential action by the receptors was observed in the seizure-induced mortality rate, with increased fatality in Y2-/- mice. In addition, although NPY overexpression did not significantly affect the mortality rate in Y2-/- and wild-type mice, it abolished KA-induced mortality in Y1-/-mice. CONCLUSIONS: This study shows for the first time an altered susceptibility to chemically induced seizures in Y1 and Y2 knockout mice and demonstrates a differential seizure modulation mediated by these receptors via a genetic approach.  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