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   533059篇
  免费   27786篇
  国内免费   507篇
耳鼻咽喉   6724篇
儿科学   17150篇
妇产科学   12617篇
基础医学   92973篇
口腔科学   12391篇
临床医学   48858篇
内科学   96207篇
皮肤病学   11896篇
神经病学   34277篇
特种医学   19816篇
外国民族医学   54篇
外科学   78405篇
综合类   7633篇
现状与发展   2篇
一般理论   108篇
预防医学   38773篇
眼科学   11968篇
药学   41560篇
  1篇
中国医学   1130篇
肿瘤学   28809篇
  2021年   3946篇
  2018年   5791篇
  2017年   4167篇
  2016年   4903篇
  2015年   5406篇
  2014年   7173篇
  2013年   10606篇
  2012年   15700篇
  2011年   17522篇
  2010年   10027篇
  2009年   8901篇
  2008年   15845篇
  2007年   17591篇
  2006年   17072篇
  2005年   16385篇
  2004年   16032篇
  2003年   15386篇
  2002年   14919篇
  2001年   22542篇
  2000年   23094篇
  1999年   19030篇
  1998年   5279篇
  1997年   4397篇
  1996年   4431篇
  1995年   4137篇
  1992年   14475篇
  1991年   15882篇
  1990年   16014篇
  1989年   15698篇
  1988年   14366篇
  1987年   14265篇
  1986年   13199篇
  1985年   12735篇
  1984年   9425篇
  1983年   8037篇
  1982年   4195篇
  1979年   8975篇
  1978年   6408篇
  1977年   5164篇
  1976年   5528篇
  1975年   6622篇
  1974年   7441篇
  1973年   7179篇
  1972年   6620篇
  1971年   6321篇
  1970年   5897篇
  1969年   5473篇
  1968年   5168篇
  1967年   4628篇
  1966年   3971篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
The paper presents the results of experimental and clinical testing of 3-hydroxypyridine derivatives (emoxipin, mexidol and new compounds) various extreme conditions (hypoxia, hyper- and hypothermia, vibration, hypokinesia, ionizing and nonionizing radiation and others). Analysis of the results led to the conclusion that 3-hydroxipiridine derivatives are a group of compounds worthy of further in-depth investigations in a broad range of extreme conditions in order to assess their potential use in development of new medical protectors of humans and animals facing extreme factors of various nature.  相似文献   
992.
993.
994.
995.
The aim of the study was to assess both p27 and p53 expression in the stromal and epithelial component of carcinosarcoma and to assess if their expression in the latter is different than in endometrial carcinoma. Immunohistochemical staining for p27 and p53 was performed on paraffin-embedded tissue blocks of 18 uterine specimens with carcinosarcoma and their expression assessed. Their expression in the epithelial element was also compared to that in 35 paraffin-embedded tissue blocks of endometrial endometrioid carcinoma. Reduced p27 expression was observed in a similarly high proportion of the stromal (77.8%) as well as of the epithelial component (66.7%) of carcinosarcoma. Although statistically not significant, the proportion of reduced p27 expression in endometrial carcinoma (85.7%) was higher than in the epithelial element of carcinosarcoma. The percentage of p53 overexpression in both elements of carcinosarcomas and in endometrial carcinomas was low and also similar (27.8 and 20.0%, respectively). Our results indicate that reduced p27 expression is common and p53 overexpression is infrequent in carcinosarcoma. Their similar rates of expression in the stromal and epithelial elements of the tumor support the contention of a monoclonal origin of carcinosarcoma. Unexpectedly, reduced p27 expression is more common in endometrial carcinoma than in the epithelial element of carcinosarcoma, in spite of the less favorable prognosticators and outcome in the latter. Further studies of p27 expression in carcinosarcoma are indicated to establish its clinical value in this aggressive malignancy.  相似文献   
996.
997.
The worldwide shortage of organs for transplantation makes it important to understand why some oppose donation. Attitudes vary with religion and ethnicity. Accordingly, we undertook a qualitative study of the attitudes of 141 U.K. Muslim Indo-Asians to organ donation. Participants were observed, focus group discussions held and in-depth individual interviews conducted. We identified a high level of alienation from the health care system in general. With respect to organ donation in particular, its importance was generally discounted, often in deference to authority figures within the community who appeared negatively disposed. The culture-specific issues arguing against donation included a sense of the sacredness of the body, a fatalistic approach to illness, a belief that organs took on an independent role as 'witnesses' to an individual's life on Judgement Day and an anxiety that the donor would have no control of the probity of the recipient of an organ. We believe these data suggest a need to improve in a culturally sensitive fashion the provision of health information provided to this community.  相似文献   
998.
999.
1000.
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