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   3757935篇
  免费   311893篇
  国内免费   14624篇
耳鼻咽喉   50659篇
儿科学   119229篇
妇产科学   97598篇
基础医学   590153篇
口腔科学   102128篇
临床医学   339045篇
内科学   671019篇
皮肤病学   98424篇
神经病学   316398篇
特种医学   146764篇
外国民族医学   262篇
外科学   580404篇
综合类   113819篇
现状与发展   23篇
一般理论   2357篇
预防医学   308148篇
眼科学   88778篇
药学   260588篇
  23篇
中国医学   11430篇
肿瘤学   187203篇
  2021年   55578篇
  2020年   35384篇
  2019年   58482篇
  2018年   72715篇
  2017年   55156篇
  2016年   61036篇
  2015年   74751篇
  2014年   109017篇
  2013年   174442篇
  2012年   104370篇
  2011年   106252篇
  2010年   120717篇
  2009年   123642篇
  2008年   92782篇
  2007年   97376篇
  2006年   106854篇
  2005年   101637篇
  2004年   103335篇
  2003年   93287篇
  2002年   82633篇
  2001年   136073篇
  2000年   129629篇
  1999年   121995篇
  1998年   68585篇
  1997年   65259篇
  1996年   62994篇
  1995年   58540篇
  1994年   52522篇
  1993年   48890篇
  1992年   85035篇
  1991年   80952篇
  1990年   76661篇
  1989年   75101篇
  1988年   69019篇
  1987年   67189篇
  1986年   63526篇
  1985年   62763篇
  1984年   54873篇
  1983年   49574篇
  1982年   43617篇
  1981年   40987篇
  1980年   38458篇
  1979年   44840篇
  1978年   38233篇
  1977年   34916篇
  1976年   31960篇
  1975年   30782篇
  1974年   32482篇
  1973年   31179篇
  1972年   29033篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
31.
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   
32.
33.
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   
34.
35.
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   
36.
37.
38.
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   
39.
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   
40.
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