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   1726911篇
  免费   128053篇
  国内免费   3968篇
耳鼻咽喉   22119篇
儿科学   56316篇
妇产科学   46801篇
基础医学   245496篇
口腔科学   50122篇
临床医学   153772篇
内科学   342729篇
皮肤病学   39492篇
神经病学   134051篇
特种医学   64487篇
外国民族医学   242篇
外科学   262260篇
综合类   39143篇
现状与发展   4篇
一般理论   540篇
预防医学   127033篇
眼科学   41011篇
药学   125562篇
  7篇
中国医学   4604篇
肿瘤学   103141篇
  2021年   14095篇
  2019年   14619篇
  2018年   21237篇
  2017年   15954篇
  2016年   17359篇
  2015年   19947篇
  2014年   27601篇
  2013年   39669篇
  2012年   55447篇
  2011年   58344篇
  2010年   34351篇
  2009年   32198篇
  2008年   53795篇
  2007年   57147篇
  2006年   57441篇
  2005年   54585篇
  2004年   52530篇
  2003年   49714篇
  2002年   47864篇
  2001年   92040篇
  2000年   93821篇
  1999年   77203篇
  1998年   19999篇
  1997年   17522篇
  1996年   17582篇
  1995年   16881篇
  1994年   15426篇
  1993年   14193篇
  1992年   57489篇
  1991年   55381篇
  1990年   53069篇
  1989年   50798篇
  1988年   46172篇
  1987年   44980篇
  1986年   42282篇
  1985年   40038篇
  1984年   29404篇
  1983年   24950篇
  1982年   13961篇
  1979年   25554篇
  1978年   17596篇
  1977年   14919篇
  1976年   13891篇
  1975年   14581篇
  1974年   17666篇
  1973年   16959篇
  1972年   15684篇
  1971年   14469篇
  1970年   13442篇
  1969年   12525篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
43.
44.
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   
45.
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   
46.
47.
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   
48.
49.
50.
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