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   4386489篇
  免费   340412篇
  国内免费   15612篇
耳鼻咽喉   60561篇
儿科学   140046篇
妇产科学   114976篇
基础医学   669553篇
口腔科学   118497篇
临床医学   399696篇
内科学   796670篇
皮肤病学   108165篇
神经病学   370546篇
特种医学   170445篇
外国民族医学   754篇
外科学   659680篇
综合类   123237篇
现状与发展   25篇
一般理论   2615篇
预防医学   361995篇
眼科学   101320篇
药学   310177篇
  34篇
中国医学   12854篇
肿瘤学   220667篇
  2021年   57428篇
  2020年   36638篇
  2019年   59574篇
  2018年   75226篇
  2017年   57690篇
  2016年   63849篇
  2015年   77022篇
  2014年   111483篇
  2013年   177160篇
  2012年   126333篇
  2011年   131124篇
  2010年   127004篇
  2009年   128635篇
  2008年   116939篇
  2007年   124122篇
  2006年   132754篇
  2005年   126756篇
  2004年   127865篇
  2003年   117908篇
  2002年   107062篇
  2001年   167439篇
  2000年   162498篇
  1999年   149153篇
  1998年   71857篇
  1997年   67742篇
  1996年   65759篇
  1995年   61138篇
  1994年   55061篇
  1993年   51081篇
  1992年   106857篇
  1991年   101624篇
  1990年   97443篇
  1989年   95041篇
  1988年   87350篇
  1987年   85492篇
  1986年   80358篇
  1985年   78482篇
  1984年   65507篇
  1983年   58285篇
  1982年   47229篇
  1981年   43891篇
  1980年   41109篇
  1979年   55200篇
  1978年   44812篇
  1977年   40036篇
  1976年   36879篇
  1975年   36855篇
  1974年   39680篇
  1973年   37833篇
  1972年   35434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