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   2609543篇
  免费   205812篇
  国内免费   6329篇
耳鼻咽喉   35052篇
儿科学   86760篇
妇产科学   73379篇
基础医学   376770篇
口腔科学   75198篇
临床医学   243599篇
内科学   502191篇
皮肤病学   54451篇
神经病学   214777篇
特种医学   99707篇
外国民族医学   804篇
外科学   379887篇
综合类   62713篇
现状与发展   4篇
一般理论   995篇
预防医学   214395篇
眼科学   59226篇
药学   195614篇
  9篇
中国医学   5443篇
肿瘤学   140710篇
  2018年   27691篇
  2017年   21219篇
  2016年   23405篇
  2015年   26899篇
  2014年   37107篇
  2013年   57303篇
  2012年   77931篇
  2011年   82709篇
  2010年   48514篇
  2009年   45402篇
  2008年   77285篇
  2007年   81656篇
  2006年   82336篇
  2005年   79864篇
  2004年   77463篇
  2003年   73834篇
  2002年   72119篇
  2001年   117371篇
  2000年   121265篇
  1999年   102361篇
  1998年   29016篇
  1997年   26370篇
  1996年   26078篇
  1995年   25197篇
  1994年   23666篇
  1993年   22371篇
  1992年   83662篇
  1991年   81878篇
  1990年   79689篇
  1989年   76534篇
  1988年   71204篇
  1987年   69874篇
  1986年   66641篇
  1985年   64172篇
  1984年   48280篇
  1983年   41487篇
  1982年   24835篇
  1981年   22124篇
  1979年   45338篇
  1978年   31859篇
  1977年   26669篇
  1976年   25463篇
  1975年   26687篇
  1974年   32610篇
  1973年   31559篇
  1972年   29073篇
  1971年   27272篇
  1970年   25156篇
  1969年   23354篇
  1968年   21837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