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   2465267篇
  免费   179832篇
  国内免费   3635篇
耳鼻咽喉   33602篇
儿科学   79010篇
妇产科学   65739篇
基础医学   365538篇
口腔科学   68129篇
临床医学   218351篇
内科学   482128篇
皮肤病学   55126篇
神经病学   195106篇
特种医学   90797篇
外国民族医学   490篇
外科学   366794篇
综合类   48043篇
现状与发展   12篇
一般理论   868篇
预防医学   197833篇
眼科学   57687篇
药学   184590篇
  10篇
中国医学   5022篇
肿瘤学   133859篇
  2021年   21134篇
  2019年   21946篇
  2018年   30916篇
  2017年   22817篇
  2016年   25153篇
  2015年   28301篇
  2014年   39186篇
  2013年   58601篇
  2012年   82741篇
  2011年   87828篇
  2010年   51239篇
  2009年   47667篇
  2008年   81239篇
  2007年   86623篇
  2006年   87102篇
  2005年   84177篇
  2004年   80289篇
  2003年   77079篇
  2002年   74522篇
  2001年   111103篇
  2000年   114030篇
  1999年   95518篇
  1998年   27450篇
  1997年   23965篇
  1996年   24349篇
  1995年   22974篇
  1994年   21107篇
  1993年   19887篇
  1992年   73221篇
  1991年   71220篇
  1990年   69571篇
  1989年   66726篇
  1988年   61344篇
  1987年   60088篇
  1986年   56213篇
  1985年   53934篇
  1984年   40013篇
  1983年   34008篇
  1982年   20194篇
  1979年   36783篇
  1978年   26254篇
  1977年   21806篇
  1976年   20905篇
  1975年   22473篇
  1974年   26988篇
  1973年   25704篇
  1972年   24052篇
  1971年   22879篇
  1970年   21047篇
  1969年   20169篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
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   
74.
75.
76.
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   
77.
78.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
79.
80.
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