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   4344249篇
  免费   349672篇
  国内免费   14681篇
耳鼻咽喉   60390篇
儿科学   139432篇
妇产科学   114293篇
基础医学   667170篇
口腔科学   118045篇
临床医学   396537篇
内科学   789046篇
皮肤病学   107802篇
神经病学   368312篇
特种医学   169520篇
外国民族医学   753篇
外科学   656268篇
综合类   121238篇
现状与发展   24篇
一般理论   2614篇
预防医学   358185篇
眼科学   100909篇
药学   307883篇
  23篇
中国医学   11957篇
肿瘤学   218201篇
  2021年   56354篇
  2020年   35919篇
  2019年   58928篇
  2018年   74556篇
  2017年   56779篇
  2016年   62966篇
  2015年   75863篇
  2014年   110158篇
  2013年   175872篇
  2012年   124742篇
  2011年   129512篇
  2010年   126171篇
  2009年   127751篇
  2008年   115228篇
  2007年   122511篇
  2006年   131299篇
  2005年   125364篇
  2004年   126665篇
  2003年   116861篇
  2002年   106079篇
  2001年   166983篇
  2000年   162046篇
  1999年   148705篇
  1998年   71674篇
  1997年   67624篇
  1996年   65638篇
  1995年   61066篇
  1994年   54987篇
  1993年   51025篇
  1992年   106625篇
  1991年   101392篇
  1990年   97253篇
  1989年   94827篇
  1988年   87152篇
  1987年   85319篇
  1986年   80207篇
  1985年   78373篇
  1984年   65408篇
  1983年   58219篇
  1982年   47213篇
  1981年   43872篇
  1980年   41084篇
  1979年   55118篇
  1978年   44766篇
  1977年   39991篇
  1976年   36851篇
  1975年   36819篇
  1974年   39623篇
  1973年   37762篇
  1972年   35363篇
排序方式: 共有10000条查询结果,搜索用时 15 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