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   5053343篇
  免费   378295篇
  国内免费   17768篇
耳鼻咽喉   70295篇
儿科学   163037篇
妇产科学   134418篇
基础医学   755129篇
口腔科学   140557篇
临床医学   468647篇
内科学   917298篇
皮肤病学   120057篇
神经病学   423234篇
特种医学   195422篇
外国民族医学   1077篇
外科学   749574篇
综合类   140319篇
现状与发展   24篇
一般理论   2859篇
预防医学   422918篇
眼科学   118788篇
药学   359272篇
  30篇
中国医学   14024篇
肿瘤学   252427篇
  2021年   57866篇
  2019年   60220篇
  2018年   78022篇
  2017年   59915篇
  2016年   66579篇
  2015年   78932篇
  2014年   113503篇
  2013年   180301篇
  2012年   149553篇
  2011年   158330篇
  2010年   134890篇
  2009年   133642篇
  2008年   142699篇
  2007年   153070篇
  2006年   160345篇
  2005年   154207篇
  2004年   154124篇
  2003年   143812篇
  2002年   132811篇
  2001年   196269篇
  2000年   193001篇
  1999年   173819篇
  1998年   75854篇
  1997年   70589篇
  1996年   68493篇
  1995年   63975篇
  1994年   57948篇
  1993年   53627篇
  1992年   127564篇
  1991年   122474篇
  1990年   118164篇
  1989年   114633篇
  1988年   105629篇
  1987年   103544篇
  1986年   98058篇
  1985年   95288篇
  1984年   77361篇
  1983年   68299篇
  1982年   51487篇
  1981年   47615篇
  1980年   44618篇
  1979年   67602篇
  1978年   52963篇
  1977年   46385篇
  1976年   43409篇
  1975年   44091篇
  1974年   49199篇
  1973年   47126篇
  1972年   44235篇
  1971年   41120篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
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   
44.
45.
46.
47.
48.
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   
49.
50.
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