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   3827853篇
  免费   280739篇
  国内免费   5884篇
耳鼻咽喉   54550篇
儿科学   126468篇
妇产科学   107191篇
基础医学   559445篇
口腔科学   109676篇
临床医学   349174篇
内科学   729398篇
皮肤病学   83820篇
神经病学   304494篇
特种医学   144418篇
外国民族医学   1032篇
外科学   570477篇
综合类   83224篇
现状与发展   14篇
一般理论   1496篇
预防医学   306988篇
眼科学   90985篇
药学   285736篇
  17篇
中国医学   7182篇
肿瘤学   198691篇
  2018年   40818篇
  2017年   30729篇
  2016年   34364篇
  2015年   39247篇
  2014年   55228篇
  2013年   84134篇
  2012年   114922篇
  2011年   122705篇
  2010年   72837篇
  2009年   68821篇
  2008年   116019篇
  2007年   123931篇
  2006年   124937篇
  2005年   121835篇
  2004年   116965篇
  2003年   112552篇
  2002年   109607篇
  2001年   164911篇
  2000年   169088篇
  1999年   143252篇
  1998年   42946篇
  1997年   37851篇
  1996年   38161篇
  1995年   36054篇
  1994年   33616篇
  1993年   31438篇
  1992年   113892篇
  1991年   111751篇
  1990年   109468篇
  1989年   106159篇
  1988年   98272篇
  1987年   96597篇
  1986年   91800篇
  1985年   87990篇
  1984年   66232篇
  1983年   57151篇
  1982年   34529篇
  1981年   31062篇
  1979年   62955篇
  1978年   45124篇
  1977年   38146篇
  1976年   36200篇
  1975年   39393篇
  1974年   47196篇
  1973年   45547篇
  1972年   43158篇
  1971年   40568篇
  1970年   37876篇
  1969年   36179篇
  1968年   33776篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   
92.
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment.  相似文献   
93.
94.
95.
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   
96.
97.
98.
99.
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   
100.
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