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   4841682篇
  免费   393904篇
  国内免费   15403篇
耳鼻咽喉   67875篇
儿科学   151820篇
妇产科学   127961篇
基础医学   727976篇
口腔科学   139595篇
临床医学   439667篇
内科学   882419篇
皮肤病学   114498篇
神经病学   403177篇
特种医学   193128篇
外国民族医学   804篇
外科学   742502篇
综合类   141653篇
现状与发展   24篇
一般理论   2730篇
预防医学   401181篇
眼科学   114266篇
药学   346913篇
  26篇
中国医学   12687篇
肿瘤学   240087篇
  2021年   56296篇
  2019年   58913篇
  2018年   74759篇
  2017年   57203篇
  2016年   63431篇
  2015年   76434篇
  2014年   111054篇
  2013年   176421篇
  2012年   128453篇
  2011年   134401篇
  2010年   127391篇
  2009年   128394篇
  2008年   121513篇
  2007年   129728篇
  2006年   138320篇
  2005年   133252篇
  2004年   134912篇
  2003年   124716篇
  2002年   113876篇
  2001年   190081篇
  2000年   187620篇
  1999年   169551篇
  1998年   75114篇
  1997年   70220篇
  1996年   68410篇
  1995年   64027篇
  1994年   57951篇
  1993年   53885篇
  1992年   128258篇
  1991年   123818篇
  1990年   119108篇
  1989年   116105篇
  1988年   107611篇
  1987年   105519篇
  1986年   100070篇
  1985年   98372篇
  1984年   79629篇
  1983年   70256篇
  1982年   52575篇
  1981年   48509篇
  1980年   45512篇
  1979年   71018篇
  1978年   54979篇
  1977年   48484篇
  1976年   44738篇
  1975年   45374篇
  1974年   51289篇
  1973年   49272篇
  1972年   46209篇
  1971年   42957篇
排序方式: 共有10000条查询结果,搜索用时 31 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