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   4855073篇
  免费   368431篇
  国内免费   16991篇
耳鼻咽喉   67721篇
儿科学   156133篇
妇产科学   129594篇
基础医学   731828篇
口腔科学   133902篇
临床医学   448731篇
内科学   877143篇
皮肤病学   116501篇
神经病学   400227篇
特种医学   186437篇
外国民族医学   824篇
外科学   729707篇
综合类   138362篇
现状与发展   23篇
一般理论   2792篇
预防医学   412526篇
眼科学   114511篇
药学   341751篇
  30篇
中国医学   13289篇
肿瘤学   238463篇
  2021年   56787篇
  2019年   59199篇
  2018年   76017篇
  2017年   58225篇
  2016年   64461篇
  2015年   76960篇
  2014年   111564篇
  2013年   177320篇
  2012年   142132篇
  2011年   151334篇
  2010年   132222篇
  2009年   131151篇
  2008年   136124篇
  2007年   146104篇
  2006年   153565篇
  2005年   148146篇
  2004年   147581篇
  2003年   137033篇
  2002年   125803篇
  2001年   179910篇
  2000年   176436篇
  1999年   159995篇
  1998年   74121篇
  1997年   69186篇
  1996年   67255篇
  1995年   62611篇
  1994年   56719篇
  1993年   52639篇
  1992年   117653篇
  1991年   114357篇
  1990年   110198篇
  1989年   106819篇
  1988年   98712篇
  1987年   96892篇
  1986年   91778篇
  1985年   89839篇
  1984年   73550篇
  1983年   65248篇
  1982年   50223篇
  1981年   46742篇
  1980年   43816篇
  1979年   65094篇
  1978年   51708篇
  1977年   44995篇
  1976年   42497篇
  1975年   42960篇
  1974年   48256篇
  1973年   46462篇
  1972年   43593篇
  1971年   40712篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
Dosage form is a mean used for the delivery of drug to a living body. In order to get the desired effect the drug should be delivered to its site of action at such rate and concentration to achieve the maximum therapeutic effect and minimum adverse effect. Since oral route is still widely accepted route but having a common drawback of difficulty in swallowing of tablets and capsules. Therefore a lot of research has been done on novel drug delivery systems. This review is about oral dispersible tablets a novel approach in drug delivery systems that are now a day''s more focused in formulation world, and laid a new path that, helped the patients to build their compliance level with the therapy, also reduced the cost and ease the administration especially in case of pediatrics and geriatrics. Quick absorption, rapid onset of action and reduction in drug loss properties are the basic advantages of this dosage form.  相似文献   
54.
55.
56.
57.
58.
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   
59.
60.
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   
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