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   3651篇
  免费   279篇
  国内免费   24篇
耳鼻咽喉   20篇
儿科学   50篇
妇产科学   118篇
基础医学   537篇
口腔科学   43篇
临床医学   396篇
内科学   752篇
皮肤病学   66篇
神经病学   309篇
特种医学   254篇
外科学   561篇
综合类   30篇
一般理论   3篇
预防医学   141篇
眼科学   63篇
药学   251篇
中国医学   2篇
肿瘤学   358篇
  2024年   9篇
  2023年   62篇
  2022年   92篇
  2021年   199篇
  2020年   119篇
  2019年   138篇
  2018年   158篇
  2017年   110篇
  2016年   115篇
  2015年   142篇
  2014年   161篇
  2013年   187篇
  2012年   285篇
  2011年   269篇
  2010年   149篇
  2009年   120篇
  2008年   162篇
  2007年   203篇
  2006年   166篇
  2005年   158篇
  2004年   139篇
  2003年   123篇
  2002年   133篇
  2001年   56篇
  2000年   54篇
  1999年   41篇
  1998年   41篇
  1997年   23篇
  1996年   18篇
  1995年   12篇
  1994年   12篇
  1992年   27篇
  1991年   29篇
  1990年   22篇
  1989年   13篇
  1988年   24篇
  1987年   15篇
  1986年   19篇
  1985年   19篇
  1984年   10篇
  1983年   7篇
  1981年   12篇
  1979年   10篇
  1978年   6篇
  1977年   11篇
  1975年   6篇
  1974年   9篇
  1973年   6篇
  1971年   8篇
  1970年   5篇
排序方式: 共有3954条查询结果,搜索用时 31 毫秒
51.
52.
53.
Reconstructions of large surgical defects of the central part of the nose pose a challenge for the surgeon due to its cosmetically prominent location. Treatment options include second intention healing, full‐thickness skin grafts and various local flaps. In the present case the “Peng flap” was used for the reconstruction of a 3.1 × 7 cm sized deep defect of the convex curve of the central nasal area in a 66‐year‐old woman. The Peng flap was performed as single‐stage procedure without complications. Good cosmetic outcome was provided by the use of adjacent skin from the lax perinasal area, the placement of the scar lines between facial cosmetic units, and the excellent tissue match for the sebaceous nasal skin. Considering the few complications of a single‐stage procedure associated with an excellent aesthetic outcome, the Peng flap should be considered not only as an effective choice for reconstruction of the cosmetically complex midline nasal tip but also the convex curve of the central nose.  相似文献   
54.
55.
56.
57.
Within the mode-coupling theory (MCT) of the glass transition, we reconsider the numerical schemes to evaluate the MCT functional. Here we propose nonuniform discretizations of the wave number, in contrast to the standard equidistant grid, in order to decrease the number of grid points without losing accuracy. We discuss in detail how the integration scheme on the new grids has to be modified from standard Riemann integration. We benchmark our approach by solving the MCT equations numerically for mono-disperse hard disks and hard spheres and by computing the critical packing fraction and the nonergodicity parameters. Our results show that significant improvements in performance can be obtained employing a nonuniform grid.  相似文献   
58.
59.

Background

Arousal and sleep represent basic domains of behavior, and alterations are of high clinical importance.

Objective/hypothesis

The aim of this study was to further elucidate the neurobiology of insomnia disorder (ID) and the potential for new treatment developments, based on the modulation of cortical activity through the non-invasive brain stimulation technique transcranial direct current stimulation (tDCS). Specifically, we tested the hypotheses that bi-frontal anodal tDCS shortens and cathodal tDCS prolongs total sleep time in patients with ID, compared to sham stimulation. Furthermore, we tested for differences in indices of arousal between ID patients and healthy controls and explored their potential impact on tDCS effects.

Methods

Nineteen ID patients underwent a within-subject repeated-measures sleep laboratory study with adaptation, baseline and three experimental nights. Bifrontal anodal, cathodal and sham tDCS was delivered in a counterbalanced order immediately prior to sleep. Wake EEG was recorded prior to and after tDCS as well as on the following morning. Subsequently, we compared patients with ID to a healthy control group from an earlier dataset.

Results

Against our hypothesis, we did not observe any tDCS effects on sleep continuity or sleep architecture in patients with ID. Further analyses of nights without stimulation demonstrated significantly increased levels of arousal in ID patients compared to healthy controls, as indexed by subjective reports, reduced total sleep time, increased wake after sleep onset and increased high frequency EEG power during wakefulness and NREM sleep. Of note, indices of increased arousal predicted the lack of effect of tDCS in ID patients.

Conclusions

Our study characterizes for the first time differential effects of tDCS on sleep in patients with ID and healthy controls, presumably related to persistent hyperarousal in ID. These findings suggest that adapted tDCS protocols need to be developed to modulate arousal and sleep dependent on baseline arousal levels.  相似文献   
60.
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