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   2436739篇
  免费   177091篇
  国内免费   4976篇
耳鼻咽喉   32633篇
儿科学   78824篇
妇产科学   64754篇
基础医学   356911篇
口腔科学   64495篇
临床医学   217395篇
内科学   476346篇
皮肤病学   53076篇
神经病学   195197篇
特种医学   92053篇
外国民族医学   489篇
外科学   371460篇
综合类   48302篇
现状与发展   12篇
一般理论   848篇
预防医学   192263篇
眼科学   55109篇
药学   179032篇
  9篇
中国医学   4584篇
肿瘤学   135014篇
  2021年   18982篇
  2019年   19563篇
  2018年   35497篇
  2017年   27313篇
  2016年   31635篇
  2015年   26693篇
  2014年   37249篇
  2013年   55769篇
  2012年   77408篇
  2011年   87357篇
  2010年   53753篇
  2009年   50074篇
  2008年   82624篇
  2007年   89342篇
  2006年   81256篇
  2005年   79944篇
  2004年   76949篇
  2003年   75302篇
  2002年   72006篇
  2001年   109671篇
  2000年   112397篇
  1999年   94245篇
  1998年   27718篇
  1997年   24484篇
  1996年   24880篇
  1995年   23663篇
  1994年   21738篇
  1993年   20445篇
  1992年   72749篇
  1991年   70757篇
  1990年   68988篇
  1989年   66203篇
  1988年   60816篇
  1987年   59700篇
  1986年   55652篇
  1985年   53535篇
  1984年   39743篇
  1983年   33771篇
  1982年   20250篇
  1979年   36173篇
  1978年   25881篇
  1977年   21383篇
  1976年   20524篇
  1975年   21937篇
  1974年   26278篇
  1973年   24897篇
  1972年   23296篇
  1971年   22104篇
  1970年   20336篇
  1969年   19395篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Henna, derived from a combination of natural leaves and coloring additives, is a common decorative dye traditionally used in many Islamic religious celebrations. Para‐phenylenediamine (PPD), a major component of black henna tattoo, is a strong sensitizer and common allergen. We report a case of severe connubial allergic contact dermatitis after black henna heterotransfer in a girl.  相似文献   
62.
63.
64.
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   
65.
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   
66.
67.
68.
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   
69.
70.
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