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   2325166篇
  免费   175446篇
  国内免费   5588篇
耳鼻咽喉   30430篇
儿科学   75798篇
妇产科学   64682篇
基础医学   344361篇
口腔科学   64936篇
临床医学   223198篇
内科学   447978篇
皮肤病学   48384篇
神经病学   191370篇
特种医学   84922篇
外国民族医学   603篇
外科学   325377篇
综合类   50435篇
现状与发展   4篇
一般理论   978篇
预防医学   197879篇
眼科学   52098篇
药学   171434篇
  12篇
中国医学   4780篇
肿瘤学   126541篇
  2019年   19161篇
  2018年   26275篇
  2017年   20030篇
  2016年   21751篇
  2015年   24957篇
  2014年   34637篇
  2013年   53506篇
  2012年   73083篇
  2011年   77807篇
  2010年   45206篇
  2009年   42515篇
  2008年   72064篇
  2007年   76745篇
  2006年   76468篇
  2005年   74370篇
  2004年   71215篇
  2003年   67972篇
  2002年   65786篇
  2001年   101832篇
  2000年   104442篇
  1999年   88001篇
  1998年   25227篇
  1997年   22935篇
  1996年   22986篇
  1995年   21812篇
  1994年   20368篇
  1993年   19089篇
  1992年   70298篇
  1991年   69232篇
  1990年   67146篇
  1989年   64251篇
  1988年   59557篇
  1987年   58401篇
  1986年   55704篇
  1985年   53110篇
  1984年   40139篇
  1983年   34785篇
  1982年   20866篇
  1979年   37554篇
  1978年   27228篇
  1977年   22466篇
  1976年   21550篇
  1975年   22593篇
  1974年   27613篇
  1973年   27206篇
  1972年   25372篇
  1971年   23732篇
  1970年   22211篇
  1969年   20622篇
  1968年   19443篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
11.
12.
13.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
14.
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   
15.
16.
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   
17.
18.
19.
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   
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