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   122903篇
  免费   6364篇
  国内免费   153篇
耳鼻咽喉   1840篇
儿科学   5316篇
妇产科学   4042篇
基础医学   17396篇
口腔科学   3182篇
临床医学   8981篇
内科学   23111篇
皮肤病学   3460篇
神经病学   9530篇
特种医学   5244篇
外国民族医学   34篇
外科学   19907篇
综合类   1625篇
一般理论   32篇
预防医学   6441篇
眼科学   3440篇
药学   8554篇
  2篇
中国医学   333篇
肿瘤学   6950篇
  2018年   995篇
  2017年   887篇
  2016年   1208篇
  2015年   1333篇
  2014年   1764篇
  2013年   2614篇
  2012年   3393篇
  2011年   3442篇
  2010年   2163篇
  2009年   2147篇
  2008年   3564篇
  2007年   3797篇
  2006年   3977篇
  2005年   4044篇
  2004年   3945篇
  2003年   3827篇
  2002年   3788篇
  2001年   7237篇
  2000年   7179篇
  1999年   6060篇
  1998年   1696篇
  1997年   1659篇
  1996年   1410篇
  1995年   1289篇
  1994年   1162篇
  1993年   1185篇
  1992年   3917篇
  1991年   3719篇
  1990年   3693篇
  1989年   3471篇
  1988年   3116篇
  1987年   3003篇
  1986年   2909篇
  1985年   2693篇
  1984年   2039篇
  1983年   1660篇
  1982年   978篇
  1981年   964篇
  1980年   810篇
  1979年   1878篇
  1978年   1410篇
  1977年   1158篇
  1976年   978篇
  1975年   1241篇
  1974年   1274篇
  1973年   1246篇
  1972年   1085篇
  1971年   1022篇
  1970年   915篇
  1969年   822篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Two young men with longstanding suprapatellar masses are presented. The initial clinical diagnosis was of a synovial or soft tissue tumour. Magnetic resonance imaging showed the features of an arteriovenous malformation (AVM). Surgical exploration and biopsy confirmed the diagnosis. AVMs, although rare, should be considered as a possible diagnosis of a peri-articular swelling of the knee.  相似文献   
62.
We investigated the effects of anti-psoriatic therapy with dithranol (1/20-1%) in salicylic acid (0.5%) in white petrolatum on lesional skin. FITC-labeled lectins and pemphigus vulgaris antibodies (PV) served as analytical means to study the glycocalyx. Antibodies of bullous pemphigoid (BP) were used as basal membrane markers. Nuclear antigens were recorded according to the binding of speckled, anti-nuclear antibodies (ANA) as well as antibodies to dsDNA. With some lectins, dithranol therapy resulted in pronounced fluorescence of the lower parts of the basal cells. ConA was fixed by the basal cell layer. To a lesser degree, ANA were fixed by nuclei of keratinocytes. PV antibodies were not fixed at all.  相似文献   
63.
64.
65.
BACKGROUND AND AIMS: Liver surgery is developing with new techniques and treatment modalities. The aim of this study is to describe liver surgery over a long period of time in a country with a public health care system. PATIENTS AND METHOD: A register study including adult patients admitted for liver resection in Sweden (population 8.8 million) selected from the Inpatient Register 1987-99. Additional data were collected from the Swedish Cancer Register and the Cause of Death Register. Analyses of the patients, indications, mortality and causes of death are presented. RESULTS: 2,405 operations were performed (21 per million per year). The most frequent indication was colorectal metastases (27%). The 5-year survival after an operation for primary liver cancer and colorectal liver metastases was 27% and 26%, respectively. CONCLUSIONS: Few patients were admitted for liver operations compared to expected figures. The survival rates are in conformity with those previously published. With an increasing awareness of the relatively favourable prognosis and the introduction of new methods, the volume of liver operations will probably increase in Sweden.  相似文献   
66.
The effects of acute stress exposure upon cholecystokinin (CCK) and substance P (SP) concentrations in discrete hypothalamic regions of the adult male rat brain were studied. Animals were exposed to foot shock stress for periods of 2, 4, 10, 30 or 60 min duration; immediately afterwards they were decapitated; brains were frozen and subsequently microdissected. CCK and SP concentrations were assayed by a specific RIA, as were serum levels of ACTH, corticosterone, PRL, GH, LH and testosterone. Stress had no effect upon SP concentrations in the anterior or posterior parts of the arcuate nucleus (ARC), but led to elevated CCK levels in the posterior ARC following 60 min of exposure. In both the ventromedial and dorsomedial hypothalamic areas, stress induced depletions of both neuropeptides. In the anterior (but not the posterior) portions of the lateral hypothalamic area, CCK and SP concentrations were reduced by stress exposure. These studies demonstrate that discrete hypothalamic CCK and SP neuronal systems are responsive to stress. This suggests that endogenous hypothalamic CCK and SP participate, along with other neurotransmitters/neuromodulators, in the integrated hypothalamic stress response, and mediate stress-neuroendocrine interactions.  相似文献   
67.
Activating effect of substance P on nerve tissue in culture   总被引:1,自引:0,他引:1  
The effect of substance P on organotypic culture of rat sympathetic ganglia and spinal cord was studied. Substance P was able to stimulate the fibre outgrowth from explant, to increase the numbers of glial and fibroblasttypic cells in ganglia growth zone. The effect was observed in the range from 10(-5) to 10(-12) M (for sympathetic ganglia) and from 10(-5) to 10(-14) M (for spinal cord culture). It is suggested that substance P can be used as a nonspecific growth factor for peripheral and central nervous tissue.  相似文献   
68.
69.
At independence in 1961, Tanzania inherited a classic economic structure from Britain. The most immediate aims of the new government included replacing the colonial administration with trained nationals, radical change of the development philosophy and strategies and development of self-reliance in all development sectors. The Arusha Declaration of 1967 was the turning point in Tanzania and achievements in all the sectors can be measured against targets established soon after. This paper examines development in the health sector within the wider national framework.  相似文献   
70.
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