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   513936篇
  免费   33362篇
  国内免费   614篇
耳鼻咽喉   6893篇
儿科学   16838篇
妇产科学   13521篇
基础医学   85011篇
口腔科学   14473篇
临床医学   44338篇
内科学   93604篇
皮肤病学   12154篇
神经病学   36181篇
特种医学   18453篇
外国民族医学   63篇
外科学   77035篇
综合类   8471篇
一般理论   118篇
预防医学   38966篇
眼科学   12134篇
药学   40537篇
中国医学   1006篇
肿瘤学   28116篇
  2018年   4930篇
  2015年   4508篇
  2014年   6059篇
  2013年   9544篇
  2012年   12866篇
  2011年   14268篇
  2010年   8299篇
  2009年   7770篇
  2008年   13692篇
  2007年   14695篇
  2006年   14938篇
  2005年   14353篇
  2004年   14045篇
  2003年   13387篇
  2002年   13266篇
  2001年   24067篇
  2000年   25078篇
  1999年   20555篇
  1998年   5426篇
  1997年   4705篇
  1996年   5041篇
  1995年   4625篇
  1994年   4318篇
  1993年   4135篇
  1992年   15726篇
  1991年   16309篇
  1990年   16422篇
  1989年   15796篇
  1988年   14575篇
  1987年   14419篇
  1986年   13597篇
  1985年   12975篇
  1984年   9627篇
  1983年   8247篇
  1982年   4559篇
  1981年   4229篇
  1979年   9418篇
  1978年   6855篇
  1977年   5772篇
  1976年   5602篇
  1975年   6396篇
  1974年   7634篇
  1973年   7130篇
  1972年   6960篇
  1971年   6685篇
  1970年   6172篇
  1969年   5888篇
  1968年   5559篇
  1967年   5012篇
  1966年   4450篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Management of splenic injuries in children has evolved over the past two decades. Splenectomies or splenorrhaphies are now performed infrequently, with the majority of hemodynamically stable children with splenic injuries managed nonoperatively. This article reviews the imaging features of acute splenic injuries in children as well as the appearance of healing splenic injuries. Follow-up evaluation and outcomes in children with splenic injuries also are addressed.  相似文献   
52.
53.
54.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy.  相似文献   
55.
Maya families from Guatemala migrated to the United States in record numbers from the late 1970s to the early 1990s. Births to Maya immigrant women have created a sizable number of Maya American children. The height and sitting height of 5 to 12 years children (n = 431) were measured in 1999 and 2000. Leg length was estimated and the sitting height ratio was calculated. These data were compared with a sample of Maya children living in Guatemala measured in 1998 (n = 1,347). Maya American children are currently 11.54 cm taller and 6.83 cm longer‐legged, on average, than Maya children living in Guatemala. Consequently, the Maya Americans have a significantly lower average sitting height ratio (i.e., relatively longer legs in proportion to length of the head and trunk) than do the Maya in Guatemala. These results add support to the hypothesis that both the height and body proportions of human populations are sensitive indicators of the quality of the environment for growth. Am. J. Hum. Biol. 14:753–761, 2002. © 2002 Wiley‐Liss, Inc.  相似文献   
56.
57.
58.
59.
Formulae for the calculation of the count of microorganisms isolated from natural bacterial biocenoses of a child's body have been derived. The authors suggest a variant of simplified drip method for the computation of microorganism colonies in solid media. The described method helps cut down the nutrient media consumption at least 3-fold and is time-saving.  相似文献   
60.
Perceptual asymmetry on a series of four specially constructed dichotic word tests was found to change as a function of the emotional quality of the words in the tests (P = 0.05). This was most pronounced in the case of positively valued words which produced an increase in asymmetry consistent with facilitated left-hemisphere function (P less than 0.004). Changes in asymmetry with emotion differed as a function of personality characteristics of the subjects, with repressors and high anxious subjects showing an increase with emotion while true low anxious subjects showed a decrease (P less than 0.02). Personality groups also differed in asymmetry on an emotionally neutral test (P less than 0.04) and in changes in asymmetry over time independent of emotion (P less than 0.001). These data suggest that emotion mediated activation of the left hemisphere may facilitate information processing within that hemisphere. Moreover, they indicate that dichotic listening tests may provide a non-invasive and inexpensive method for assessing emotion mediated changes in brain state that are clinically relevant.  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