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   5828666篇
  免费   449735篇
  国内免费   17370篇
耳鼻咽喉   84206篇
儿科学   185491篇
妇产科学   156060篇
基础医学   852272篇
口腔科学   168960篇
临床医学   543033篇
内科学   1063782篇
皮肤病学   132275篇
神经病学   485087篇
特种医学   228481篇
外国民族医学   1640篇
外科学   868301篇
综合类   165893篇
现状与发展   24篇
一般理论   3196篇
预防医学   494383篇
眼科学   140723篇
药学   420822篇
  25篇
中国医学   14823篇
肿瘤学   286294篇
  2021年   57902篇
  2019年   60168篇
  2018年   78892篇
  2017年   60245篇
  2016年   67259篇
  2015年   78802篇
  2014年   113839篇
  2013年   179866篇
  2012年   167501篇
  2011年   180463篇
  2010年   139205篇
  2009年   136568篇
  2008年   164862篇
  2007年   178632篇
  2006年   183974篇
  2005年   178379篇
  2004年   178361篇
  2003年   167440篇
  2002年   156292篇
  2001年   236825篇
  2000年   236351篇
  1999年   208496篇
  1998年   82142篇
  1997年   74988篇
  1996年   72834篇
  1995年   68608篇
  1994年   62605篇
  1993年   57852篇
  1992年   157663篇
  1991年   152403篇
  1990年   147116篇
  1989年   142489篇
  1988年   131899篇
  1987年   129939篇
  1986年   123049篇
  1985年   119666篇
  1984年   94650篇
  1983年   82819篇
  1982年   57822篇
  1981年   53223篇
  1979年   86178篇
  1978年   65294篇
  1977年   56512篇
  1976年   53055篇
  1975年   54693篇
  1974年   63782篇
  1973年   61251篇
  1972年   57778篇
  1971年   53439篇
  1970年   50001篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
31.
32.
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   
33.
34.
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   
35.
36.
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   
37.
38.
39.
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   
40.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.  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