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   2516053篇
  免费   177892篇
  国内免费   3399篇
耳鼻咽喉   33166篇
儿科学   82534篇
妇产科学   65955篇
基础医学   365044篇
口腔科学   65317篇
临床医学   224548篇
内科学   487137篇
皮肤病学   52802篇
神经病学   201349篇
特种医学   96338篇
外国民族医学   491篇
外科学   380849篇
综合类   49857篇
现状与发展   12篇
一般理论   853篇
预防医学   199616篇
眼科学   57004篇
药学   184641篇
  10篇
中国医学   5215篇
肿瘤学   144606篇
  2021年   19609篇
  2019年   20330篇
  2018年   46989篇
  2017年   36132篇
  2016年   40365篇
  2015年   27168篇
  2014年   37641篇
  2013年   55787篇
  2012年   82220篇
  2011年   99150篇
  2010年   64140篇
  2009年   55478篇
  2008年   92697篇
  2007年   99553篇
  2006年   81840篇
  2005年   80640篇
  2004年   78357篇
  2003年   76448篇
  2002年   72409篇
  2001年   109125篇
  2000年   111952篇
  1999年   93783篇
  1998年   27349篇
  1997年   23990篇
  1996年   24235篇
  1995年   22921篇
  1994年   21076篇
  1993年   19843篇
  1992年   72087篇
  1991年   70218篇
  1990年   68568篇
  1989年   65770篇
  1988年   60391篇
  1987年   59193篇
  1986年   55286篇
  1985年   53069篇
  1984年   39370篇
  1983年   33467篇
  1982年   19930篇
  1979年   35889篇
  1978年   25687篇
  1977年   21268篇
  1976年   20378篇
  1975年   21852篇
  1974年   26202篇
  1973年   24823篇
  1972年   23217篇
  1971年   22051篇
  1970年   20272篇
  1969年   19345篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
62.
While previous randomised controlled trials and meta-analyses offer only limited evidence for the effectiveness of cognitive rehabilitation, qualitative studies examining patient perspectives report more positive outcomes. This meta-synthesis of qualitative studies examined patient perspectives of cognitive rehabilitation for memory, attention, and executive function problems in people with multiple sclerosis. Using set eligibility criteria, we screened electronic databases, reference lists, and academic networks for relevant papers. Seven papers (195 participants) were selected. Two independent researchers conducted quality appraisals of papers. Data analysis, guided by the thematic synthesis approach, yielded six main themes. These suggested that patients benefitted from the group environment in rehabilitation. Cognitive rehabilitation facilitated the participants’ reflection and awareness of their cognitive deficits, and was associated with increased knowledge and understanding of their illness. Increased strategy use was reported and associated with improvements in cognitive functioning and greater confidence and perseverance. Participants reported emotional and social improvements, and felt more optimistic. Overall, these changes had a positive impact on participants’ quality of life. This synthesis of qualitative studies indicates that people with multiple sclerosis who experience cognitive deficits benefit from cognitive rehabilitation programmes. This finding must, however, be viewed in light of the limitations of this meta-synthesis. The meta-synthesis was registered in the PROSPERO database under CRD42017040148.  相似文献   
63.
We report two British cases of liver abscess, due to Klebsiella pneumoniae and associated with synchronous infection elsewhere, which required liver resection for definitive treatment. They illustrate the geographic spread of aggressive K pneumoniae liver infection and demonstrate the importance of early aggressive treatment.  相似文献   
64.
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   
65.
66.
67.
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation.  相似文献   
68.
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   
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