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   104777篇
  免费   30800篇
  国内免费   1123篇
耳鼻咽喉   2634篇
儿科学   2723篇
妇产科学   2429篇
基础医学   3803篇
口腔科学   5277篇
临床医学   26630篇
内科学   26311篇
皮肤病学   3494篇
神经病学   12908篇
特种医学   4242篇
外国民族医学   3篇
外科学   19102篇
综合类   234篇
现状与发展   40篇
一般理论   4篇
预防医学   13720篇
眼科学   2147篇
药学   1681篇
中国医学   16篇
肿瘤学   9302篇
  2024年   542篇
  2023年   5038篇
  2022年   1148篇
  2021年   2843篇
  2020年   5367篇
  2019年   2091篇
  2018年   6975篇
  2017年   7423篇
  2016年   8054篇
  2015年   8210篇
  2014年   10614篇
  2013年   12361篇
  2012年   4226篇
  2011年   4018篇
  2010年   7068篇
  2009年   9358篇
  2008年   3984篇
  2007年   2949篇
  2006年   4056篇
  2005年   2653篇
  2004年   2041篇
  2003年   1719篇
  2002年   1569篇
  2001年   1982篇
  2000年   1294篇
  1999年   1847篇
  1998年   2201篇
  1997年   2045篇
  1996年   2053篇
  1995年   1781篇
  1994年   1164篇
  1993年   997篇
  1992年   823篇
  1991年   699篇
  1990年   561篇
  1989年   589篇
  1988年   544篇
  1987年   425篇
  1986年   404篇
  1985年   334篇
  1984年   311篇
  1983年   353篇
  1982年   295篇
  1981年   250篇
  1980年   177篇
  1979年   111篇
  1978年   159篇
  1977年   150篇
  1976年   109篇
  1974年   105篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
71.
72.
In May 2017, the Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee hosted a workshop to discuss whether mode of action (MOA) investigation is enhanced through the application of the adverse outcome pathway (AOP) framework. As AOPs are a relatively new approach in genetic toxicology, this report describes how AOPs could be harnessed to advance MOA analysis of genotoxicity pathways using five example case studies. Each of these genetic toxicology AOPs proposed for further development includes the relevant molecular initiating events, key events, and adverse outcomes (AOs), identification and/or further development of the appropriate assays to link an agent to these events, and discussion regarding the biological plausibility of the proposed AOP. A key difference between these proposed genetic toxicology AOPs versus traditional AOPs is that the AO is a genetic toxicology endpoint of potential significance in risk characterization, in contrast to an adverse state of an organism or a population. The first two detailed case studies describe provisional AOPs for aurora kinase inhibition and tubulin binding, leading to the common AO of aneuploidy. The remaining three case studies highlight provisional AOPs that lead to chromosome breakage or mutation via indirect DNA interaction (inhibition of topoisomerase II, production of cellular reactive oxygen species, and inhibition of DNA synthesis). These case studies serve as starting points for genotoxicity AOPs that could ultimately be published and utilized by the broader toxicology community and illustrate the practical considerations and evidence required to formalize such AOPs so that they may be applied to genetic toxicity evaluation schemes. Environ. Mol. Mutagen. 61:114–134, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
73.
Gray platelet syndrome (GPS) is a rare (<1/1 000 000) and inherited platelet function disorder characterized by macrothrombocytopenia, α-granule deficiency, and hemorrhages. Bleeding intensity does not correlate with platelet count nor with functional test results. We hereby describe the perioperative bleeding prevention and management of a patient with GPS requiring multiple redo cardiac surgeries.  相似文献   
74.
75.
76.
77.
78.
79.
80.
ABSTRACT

Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood.  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