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   2597796篇
  免费   204720篇
  国内免费   6338篇
耳鼻咽喉   34893篇
儿科学   86206篇
妇产科学   73081篇
基础医学   375424篇
口腔科学   74927篇
临床医学   241660篇
内科学   500604篇
皮肤病学   54322篇
神经病学   213574篇
特种医学   99354篇
外国民族医学   804篇
外科学   378388篇
综合类   62372篇
现状与发展   4篇
一般理论   958篇
预防医学   212912篇
眼科学   59042篇
药学   194646篇
  9篇
中国医学   5429篇
肿瘤学   140245篇
  2018年   27456篇
  2017年   21062篇
  2016年   23235篇
  2015年   26689篇
  2014年   36802篇
  2013年   56824篇
  2012年   77304篇
  2011年   82002篇
  2010年   48094篇
  2009年   45132篇
  2008年   76686篇
  2007年   80962篇
  2006年   81592篇
  2005年   79200篇
  2004年   76799篇
  2003年   73284篇
  2002年   71623篇
  2001年   117060篇
  2000年   120943篇
  1999年   102105篇
  1998年   28873篇
  1997年   26251篇
  1996年   25986篇
  1995年   25098篇
  1994年   23586篇
  1993年   22283篇
  1992年   83454篇
  1991年   81664篇
  1990年   79493篇
  1989年   76330篇
  1988年   70999篇
  1987年   69680篇
  1986年   66455篇
  1985年   63996篇
  1984年   48121篇
  1983年   41334篇
  1982年   24709篇
  1981年   22002篇
  1979年   45144篇
  1978年   31735篇
  1977年   26547篇
  1976年   25357篇
  1975年   26586篇
  1974年   32487篇
  1973年   31453篇
  1972年   28952篇
  1971年   27186篇
  1970年   25050篇
  1969年   23271篇
  1968年   21762篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.  相似文献   
12.
13.
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.  相似文献   
14.
15.
16.
The coronavirus 2019 pandemic has affected almost every aspect of health care delivery in the United States, and the emergency medicine system has been hit particularly hard while dealing with this public health crisis. In an unprecedented time in our history, medical systems and clinicians have been asked to be creative, flexible, and innovative, all while continuing to uphold the important standards in the US health care system. To continue providing quality services to patients during this extraordinary time, care providers, organizations, administrators, and insurers have needed to alter longstanding models and procedures to respond to the dynamics of a pandemic. The Emergency Medicine Treatment and Active Labor Act of 1986, or EMTALA, is 1 example of where these alterations have allowed health care facilities and clinicians to continue their work of caring for patients while protecting both the patients and the clinicians themselves from infectious exposures at the same time.  相似文献   
17.
18.
19.
20.
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