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   4396295篇
  免费   342157篇
  国内免费   14907篇
耳鼻咽喉   61535篇
儿科学   139965篇
妇产科学   116232篇
基础医学   670374篇
口腔科学   120792篇
临床医学   397335篇
内科学   790553篇
皮肤病学   110528篇
神经病学   358318篇
特种医学   174748篇
外国民族医学   631篇
外科学   678423篇
综合类   123188篇
现状与发展   23篇
一般理论   2449篇
预防医学   359876篇
眼科学   103781篇
药学   314105篇
  28篇
中国医学   12228篇
肿瘤学   218247篇
  2021年   56447篇
  2019年   59012篇
  2018年   74564篇
  2017年   56939篇
  2016年   62981篇
  2015年   76415篇
  2014年   110994篇
  2013年   176698篇
  2012年   117790篇
  2011年   123176篇
  2010年   125633篇
  2009年   126953篇
  2008年   109499篇
  2007年   117371篇
  2006年   125849篇
  2005年   120958篇
  2004年   121709篇
  2003年   112457篇
  2002年   102222篇
  2001年   161196篇
  2000年   156059篇
  1999年   144416篇
  1998年   71355篇
  1997年   67123篇
  1996年   65095篇
  1995年   60473篇
  1994年   54387篇
  1993年   50508篇
  1992年   105027篇
  1991年   102278篇
  1990年   99420篇
  1989年   97471篇
  1988年   90126篇
  1987年   88010篇
  1986年   83649篇
  1985年   81859篇
  1984年   68053篇
  1983年   60876篇
  1982年   48032篇
  1981年   44631篇
  1980年   42151篇
  1979年   59493篇
  1978年   47444篇
  1977年   42719篇
  1976年   39401篇
  1975年   40919篇
  1974年   44338篇
  1973年   42766篇
  1972年   40216篇
  1971年   37412篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  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