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   3440368篇
  免费   305717篇
  国内免费   13851篇
耳鼻咽喉   47341篇
儿科学   108957篇
妇产科学   87675篇
基础医学   549628篇
口腔科学   93066篇
临床医学   312483篇
内科学   611783篇
皮肤病学   89331篇
神经病学   297429篇
特种医学   138020篇
外国民族医学   299篇
外科学   533874篇
综合类   106013篇
现状与发展   24篇
一般理论   2267篇
预防医学   293534篇
眼科学   78692篇
药学   237484篇
  24篇
中国医学   9548篇
肿瘤学   162464篇
  2021年   55076篇
  2020年   35058篇
  2019年   58066篇
  2018年   71291篇
  2017年   54261篇
  2016年   59950篇
  2015年   74084篇
  2014年   108381篇
  2013年   173405篇
  2012年   92153篇
  2011年   92025篇
  2010年   116530篇
  2009年   120979篇
  2008年   79154篇
  2007年   82316篇
  2006年   92937篇
  2005年   88468篇
  2004年   90473篇
  2003年   81389篇
  2002年   70522篇
  2001年   111002篇
  2000年   104601篇
  1999年   102184篇
  1998年   66163篇
  1997年   63781篇
  1996年   61980篇
  1995年   57736篇
  1994年   51749篇
  1993年   48352篇
  1992年   73485篇
  1991年   70213篇
  1990年   66538篇
  1989年   65113篇
  1988年   60386篇
  1987年   59043篇
  1986年   55862篇
  1985年   55964篇
  1984年   50411篇
  1983年   45758篇
  1982年   42547篇
  1981年   39971篇
  1980年   37667篇
  1979年   41776篇
  1978年   36569篇
  1977年   33116篇
  1976年   30458篇
  1975年   29033篇
  1974年   30266篇
  1973年   29036篇
  1972年   27041篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
202.
203.
204.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
205.
206.
207.
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.  相似文献   
208.
209.
Hepatic NADPH-cytochrome P450 oxidoreductase null (HRN?) mice exhibit normal hepatic and extrahepatic biotransformation enzyme activities when compared to wild-type (WT) mice, but express no functional hepatic cytochrome P450 activities. When incubated in vitro with [14C]-diclofenac, liver microsomes from WT mice exhibited extensive biotransformation to oxidative and glucuronide metabolites and covalent binding to proteins was also observed. In contrast, whereas glucuronide conjugates and a quinone-imine metabolite were formed when [14C]-diclofenac was incubated with HRN? mouse liver, only small quantities of P450-derived oxidative metabolites were produced in these samples and covalent binding to proteins was not observed. Livers from vehicle-treated HRN? mice exhibited enhanced lipid accumulation, bile duct proliferation, hepatocellular degeneration and necrosis and inflammatory cell infiltration, which were not present in livers from WT mice. Elevated liver-derived alanine aminotransferase, glutamate dehydrogenase and alkaline phosphatase activities were also observed in plasma from HRN? mice. When treated orally with diclofenac for 7 days, at 30 mg/kg/day, the severities of the abnormal liver histopathology and plasma liver enzyme findings in HRN? mice were reduced markedly. Oral diclofenac administration did not alter the liver histopathology or elevate plasma enzyme activities of WT mice. These findings indicate that HRN? mice are valuable for exploration of the role played by hepatic P450s in drug biotransformation, but poorly suited to investigations of drug-induced liver toxicity. Nevertheless, studies in HRN? mice could provide novel insights into the role played by inflammation in liver injury and may aid the evaluation of new strategies for its treatment.  相似文献   
210.
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