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   2616327篇
  免费   203391篇
  国内免费   4538篇
耳鼻咽喉   36317篇
儿科学   81167篇
妇产科学   67477篇
基础医学   362611篇
口腔科学   70486篇
临床医学   234659篇
内科学   512320篇
皮肤病学   49693篇
神经病学   223601篇
特种医学   107074篇
外国民族医学   889篇
外科学   401244篇
综合类   59589篇
现状与发展   1篇
一般理论   1084篇
预防医学   213589篇
眼科学   59552篇
药学   191851篇
  4篇
中国医学   5069篇
肿瘤学   145979篇
  2018年   46858篇
  2017年   36754篇
  2016年   41235篇
  2015年   25783篇
  2014年   36596篇
  2013年   54905篇
  2012年   80282篇
  2011年   97621篇
  2010年   63071篇
  2009年   54731篇
  2008年   92777篇
  2007年   100337篇
  2006年   79646篇
  2005年   79542篇
  2004年   78061篇
  2003年   76702篇
  2002年   73679篇
  2001年   113456篇
  2000年   117546篇
  1999年   99212篇
  1998年   28956篇
  1997年   26464篇
  1996年   26115篇
  1995年   25259篇
  1994年   23745篇
  1993年   22110篇
  1992年   79791篇
  1991年   76815篇
  1990年   73944篇
  1989年   71140篇
  1988年   66143篇
  1987年   65121篇
  1986年   61589篇
  1985年   58678篇
  1984年   44502篇
  1983年   37903篇
  1982年   23216篇
  1981年   20560篇
  1980年   19317篇
  1979年   41450篇
  1978年   29135篇
  1977年   24442篇
  1976年   22960篇
  1975年   24023篇
  1974年   29726篇
  1973年   28095篇
  1972年   26260篇
  1971年   24175篇
  1970年   22795篇
  1969年   21141篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.
47.
Acne vulgaris (acne) is a chronic inflammatory disease of the sebaceous gland, characterized by follicular hyperkeratinization, excessive colonization by Propionibacterium acnes (Pacnes) as well as immune reactions and inflammation. Despite an armamentarium of topical treatments available including benzoyl peroxide, retinoids and azelaic acid, topical antibiotics in monotherapies, especially erythromycin and clindamycin, are still used in Europe to treat acne. This intensive use led to antimicrobial‐resistant P. acnes and staphylococci strains becoming one of the main health issues worldwide. This is an update on the current topical acne treatments available in Europe, their mechanism of action, their potential to induce antimicrobial resistance and their clinical efficacy and safety.  相似文献   
48.
49.
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   
50.
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   
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