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   4971929篇
  免费   386612篇
  国内免费   17574篇
耳鼻咽喉   69102篇
儿科学   159998篇
妇产科学   132666篇
基础医学   746543篇
口腔科学   137780篇
临床医学   462940篇
内科学   904900篇
皮肤病学   118116篇
神经病学   417032篇
特种医学   191847篇
外国民族医学   1064篇
外科学   738644篇
综合类   139838篇
现状与发展   24篇
一般理论   2841篇
预防医学   418961篇
眼科学   116749篇
药学   353856篇
  30篇
中国医学   13826篇
肿瘤学   249358篇
  2021年   57274篇
  2019年   59644篇
  2018年   76817篇
  2017年   58969篇
  2016年   65285篇
  2015年   77722篇
  2014年   112209篇
  2013年   178429篇
  2012年   145556篇
  2011年   154096篇
  2010年   133095篇
  2009年   132244篇
  2008年   138739篇
  2007年   148534篇
  2006年   155905篇
  2005年   149639篇
  2004年   149885篇
  2003年   139505篇
  2002年   128378篇
  2001年   194467篇
  2000年   191227篇
  1999年   172322篇
  1998年   75503篇
  1997年   70365篇
  1996年   68287篇
  1995年   63790篇
  1994年   57758篇
  1993年   53500篇
  1992年   126761篇
  1991年   121705篇
  1990年   117343篇
  1989年   113843篇
  1988年   104926篇
  1987年   102891篇
  1986年   97398篇
  1985年   94670篇
  1984年   76883篇
  1983年   67952篇
  1982年   51289篇
  1981年   47447篇
  1980年   44451篇
  1979年   66998篇
  1978年   52582篇
  1977年   46108篇
  1976年   43143篇
  1975年   43660篇
  1974年   48728篇
  1973年   46689篇
  1972年   43793篇
  1971年   40700篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
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   
32.
33.
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   
34.
35.
36.
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   
37.
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   
38.
Immunoglobulin light chain amyloidosis (AL) commonly presents with nephrotic range proteinuria, heart failure with preserved ejection fraction, nondiabetic peripheral neuropathy, unexplained hepatomegaly or diarrhea, and should be considered in patients presenting with these symptoms. More importantly, patients being monitored for smoldering multiple myeloma and a monoclonal gammopathy of undetermined significance (MGUS) are at risk for developing AL amyloidosis. MGUS and myeloma patients that have atypical features, including unexplained weight loss; lower extremity edema, early satiety, and dyspnea on exertion should be considered at risk for light chain amyloidosis. Overlooking the diagnosis of light chain amyloidosis leading to therapy delay is common, and it represents an error of diagnostic consideration. Herein we provide a review of established and investigational treatments for patients with AL amyloidosis and provide algorithms for workup and management of these patients.Subject terms: Myeloma, Chemotherapy  相似文献   
39.
40.
Fibroblast growth factor receptors (FGFRs) are aberrantly activated through single-nucleotide variants, gene fusions and copy number amplifications in 5–10% of all human cancers, although this frequency increases to 10–30% in urothelial carcinoma and intrahepatic cholangiocarcinoma. We begin this review by highlighting the diversity of FGFR genomic alterations identified in human cancers and the current challenges associated with the development of clinical-grade molecular diagnostic tests to accurately detect these alterations in the tissue and blood of patients. The past decade has seen significant advancements in the development of FGFR-targeted therapies, which include selective, non-selective and covalent small-molecule inhibitors, as well as monoclonal antibodies against the receptors. We describe the expanding landscape of anti-FGFR therapies that are being assessed in early phase and randomised controlled clinical trials, such as erdafitinib and pemigatinib, which are approved by the Food and Drug Administration for the treatment of FGFR3-mutated urothelial carcinoma and FGFR2-fusion cholangiocarcinoma, respectively. However, despite initial sensitivity to FGFR inhibition, acquired drug resistance leading to cancer progression develops in most patients. This phenomenon underscores the need to clearly delineate tumour-intrinsic and tumour-extrinsic mechanisms of resistance to facilitate the development of second-generation FGFR inhibitors and novel treatment strategies beyond progression on targeted therapy.Subject terms: Cancer, Cancer  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