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   2588606篇
  免费   185151篇
  国内免费   7589篇
耳鼻咽喉   34276篇
儿科学   85225篇
妇产科学   71585篇
基础医学   363848篇
口腔科学   69684篇
临床医学   234574篇
内科学   515789篇
皮肤病学   62475篇
神经病学   213615篇
特种医学   99933篇
外国民族医学   736篇
外科学   386532篇
综合类   50393篇
现状与发展   5篇
一般理论   970篇
预防医学   196250篇
眼科学   56682篇
药学   188062篇
  8篇
中国医学   5338篇
肿瘤学   145366篇
  2021年   20049篇
  2019年   20664篇
  2018年   29345篇
  2017年   22631篇
  2016年   26277篇
  2015年   29556篇
  2014年   40513篇
  2013年   60493篇
  2012年   80339篇
  2011年   84600篇
  2010年   51057篇
  2009年   49204篇
  2008年   79120篇
  2007年   83905篇
  2006年   85630篇
  2005年   81785篇
  2004年   78774篇
  2003年   76092篇
  2002年   73370篇
  2001年   128415篇
  2000年   131335篇
  1999年   110504篇
  1998年   31259篇
  1997年   27922篇
  1996年   28222篇
  1995年   27386篇
  1994年   25068篇
  1993年   23421篇
  1992年   85161篇
  1991年   81566篇
  1990年   78784篇
  1989年   76061篇
  1988年   69469篇
  1987年   67997篇
  1986年   63544篇
  1985年   60510篇
  1984年   44941篇
  1983年   37949篇
  1982年   22456篇
  1981年   19988篇
  1979年   38961篇
  1978年   27439篇
  1977年   23252篇
  1976年   21497篇
  1975年   22813篇
  1974年   26789篇
  1973年   25370篇
  1972年   23749篇
  1971年   21956篇
  1970年   20183篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
152.
153.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia.  相似文献   
154.
155.
M Vousden 《Nursing times》1988,84(10):16-17
  相似文献   
156.
The Dundee Memory Clinic was established in 1991. This paper reviews the diagnosis of the first 150 attenders and compares the findings with those of other memory clinics.  相似文献   
157.
Fibroblasts incorporated within collagen gels induce a cell-mediated contraction of the gel to form a three-dimensional, tissue-like structure by a mechanism thought to mimic wound contraction in vivo . In this study a gel contraction model was used to investigate the ability of fibroblasts derived from adult gingiva, adult skin and fetal skin to organise a collagen matrix. In addition the effects of interleukin-1β (IL-1β) on the contraction process was also investigated. Over the concentration range 5-50 U/ml, IL-1β induced a statistically significant inhibition of gel contraction in all fibroblast cell types ( P <0.05), although fetal fibroblasts appeared least responsive and gingival fibroblasts most responsive to the inhibitory effects of this cytokine. Comparison of gel contraction by the different fibroblast strains indicated that fetal and gingival fibroblasts shared similar contraction kinetics. For the adult skin fibroblasts, three of five strains studied showed significantly diminished levels of gel contraction compared to fetal and gingival cells. This apparent difference in fibroblast phenotype may, at least in part, explain the fetal-like wound healing pattern seen in the oral mucosa.  相似文献   
158.
Membrane-bound CD14 acts as a receptor for lipopolysaccharide (LPS) on monocytes/macrophages and neutrophils. Studies have suggested that the activation of monocytes/macrophages by the binding of LPS to membrane-bound CD14 may require the association of a signal-transducing molecule with membrane-bound CD14. The observation that non-CD14 expressing cells, such as endothelial cells, can nevertheless be activated by a complex of LPS and a soluble form of CD14 (sCD14) suggests that the receptor for this complex may be identical to the signal transducing molecule associated with membrane-bound CD14. The studies described show that two CD14-specific MoAb are able to block the LPS-induced activation of endothelial cells but do not affect the response of monocytes to LPS. This suggests that the interaction of the sCD14:LPS complex with endothelial cells is distinct from the interaction of membrane-bound CD14 with its putative signal-transducing molecule.  相似文献   
159.
160.
Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did.  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