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   3822398篇
  免费   307932篇
  国内免费   15047篇
耳鼻咽喉   53530篇
儿科学   119014篇
妇产科学   100520篇
基础医学   593263篇
口腔科学   106273篇
临床医学   337139篇
内科学   688737篇
皮肤病学   100520篇
神经病学   324915篇
特种医学   150292篇
外国民族医学   585篇
外科学   591574篇
综合类   112380篇
现状与发展   24篇
一般理论   2423篇
预防医学   311874篇
眼科学   87456篇
药学   267431篇
  20篇
中国医学   11399篇
肿瘤学   186008篇
  2021年   57505篇
  2020年   36549篇
  2019年   60612篇
  2018年   76116篇
  2017年   57432篇
  2016年   63308篇
  2015年   77145篇
  2014年   111725篇
  2013年   178715篇
  2012年   108530篇
  2011年   109920篇
  2010年   123115篇
  2009年   125922篇
  2008年   95552篇
  2007年   101062篇
  2006年   110036篇
  2005年   104916篇
  2004年   106080篇
  2003年   96620篇
  2002年   86431篇
  2001年   122730篇
  2000年   116126篇
  1999年   112741篇
  1998年   66651篇
  1997年   64029篇
  1996年   61571篇
  1995年   56933篇
  1994年   51191篇
  1993年   47703篇
  1992年   79445篇
  1991年   75789篇
  1990年   72657篇
  1989年   71585篇
  1988年   66898篇
  1987年   65317篇
  1986年   62502篇
  1985年   61649篇
  1984年   54333篇
  1983年   49002篇
  1982年   43629篇
  1981年   40905篇
  1980年   38655篇
  1979年   46783篇
  1978年   39788篇
  1977年   36299篇
  1976年   32920篇
  1975年   33063篇
  1974年   35353篇
  1973年   34139篇
  1972年   32420篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
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   
34.
35.
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   
36.
37.
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   
38.
39.
40.
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   
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