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   3211219篇
  免费   256738篇
  国内免费   9314篇
耳鼻咽喉   45281篇
儿科学   100901篇
妇产科学   86438篇
基础医学   446476篇
口腔科学   91968篇
临床医学   293546篇
内科学   634771篇
皮肤病学   69687篇
神经病学   269607篇
特种医学   129022篇
外国民族医学   1111篇
外科学   489549篇
综合类   76911篇
现状与发展   3篇
一般理论   1300篇
预防医学   262279篇
眼科学   73604篇
药学   233635篇
  9篇
中国医学   5776篇
肿瘤学   165397篇
  2018年   32854篇
  2016年   29199篇
  2015年   32881篇
  2014年   46825篇
  2013年   71064篇
  2012年   92220篇
  2011年   98222篇
  2010年   59263篇
  2009年   57121篇
  2008年   92748篇
  2007年   98791篇
  2006年   99892篇
  2005年   97319篇
  2004年   93395篇
  2003年   90484篇
  2002年   88111篇
  2001年   147399篇
  2000年   152381篇
  1999年   128305篇
  1998年   38640篇
  1997年   34849篇
  1996年   35167篇
  1995年   34635篇
  1994年   32466篇
  1993年   30397篇
  1992年   104894篇
  1991年   101664篇
  1990年   98094篇
  1989年   93973篇
  1988年   87455篇
  1987年   86248篇
  1986年   81622篇
  1985年   78440篇
  1984年   59781篇
  1983年   50944篇
  1982年   31504篇
  1981年   28336篇
  1980年   26666篇
  1979年   55688篇
  1978年   39819篇
  1977年   33538篇
  1976年   31339篇
  1975年   32900篇
  1974年   40086篇
  1973年   38179篇
  1972年   35709篇
  1971年   33086篇
  1970年   30921篇
  1969年   28788篇
  1968年   26482篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
42.
43.
44.
45.
46.
47.
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   
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