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   224397篇
  免费   4192篇
  国内免费   246篇
耳鼻咽喉   1775篇
儿科学   7769篇
妇产科学   4209篇
基础医学   23462篇
口腔科学   3048篇
临床医学   17742篇
内科学   41373篇
皮肤病学   1508篇
神经病学   21247篇
特种医学   10535篇
外科学   34982篇
综合类   2639篇
一般理论   45篇
预防医学   21524篇
眼科学   3510篇
药学   12810篇
  1篇
中国医学   683篇
肿瘤学   19973篇
  2023年   301篇
  2022年   508篇
  2021年   1159篇
  2020年   763篇
  2019年   1006篇
  2018年   22943篇
  2017年   18290篇
  2016年   20575篇
  2015年   2197篇
  2014年   2519篇
  2013年   3273篇
  2012年   10647篇
  2011年   24661篇
  2010年   20964篇
  2009年   13480篇
  2008年   22502篇
  2007年   24979篇
  2006年   3688篇
  2005年   5369篇
  2004年   6316篇
  2003年   7080篇
  2002年   4994篇
  2001年   718篇
  2000年   784篇
  1999年   683篇
  1998年   776篇
  1997年   669篇
  1996年   508篇
  1995年   461篇
  1994年   407篇
  1993年   378篇
  1992年   307篇
  1991年   342篇
  1990年   365篇
  1989年   330篇
  1988年   292篇
  1987年   243篇
  1986年   230篇
  1985年   263篇
  1984年   225篇
  1983年   216篇
  1982年   232篇
  1981年   178篇
  1980年   186篇
  1979年   136篇
  1978年   150篇
  1977年   146篇
  1976年   118篇
  1975年   119篇
  1974年   114篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Die Anaesthesiologie - Phantomschmerzen haben eine hohe Prävalenz nach Majoramputationen und sind mit einer zusätzlichen Einschränkung der Lebensqualität verbunden....  相似文献   
2.
3.
Introduction: The Hedgehog (HH) pathway constitutes a collection of signaling molecules which critically influence embryogenesis. In adults, however, the HH pathway remains integral to the proliferation, maintenance, and apoptosis of adult stem cells including hematopoietic stem cells.

Areas covered: We discuss the current understanding of the HH pathway as it relates to normal hematopoiesis, the pathology of acute myeloid leukemia (AML), the rationale for and data from combination therapies including HH pathway inhibitors, and ultimately the prospects that might offer promise in targeting this pathway in AML.

Expert opinion: Efforts to target the HH pathway have been focused on impeding this disposition and restoring chemosensitivity to conventional myeloid neoplasm therapies. The year 2018 saw the first approval of a HH pathway inhibitor (glasdegib) for AML, though for an older population and in combination with an uncommonly-used therapy. Several other clinical trials with agents targeting modulators of HH signaling in AML and MDS are underway. Further study and understanding of the interplay between the numerous aspects of HH signaling and how it relates to the augmented survival of AML will provide a more reliable substrate for therapeutic strategies in patients with this poor-risk disease.  相似文献   

4.
Despite common experiences of identity damage, decline, and deterioration, many brain injury survivors succeed in reconstructing robust identities in the wake of injury. Yet, while this accomplishment greatly benefits survivors’ quality of life, little is known about how positive identity work might be facilitated or enhanced in therapeutic institutions. Drawing on data from a women’s self-help group, we argue that an egalitarian, reflective, strength-focused, and gender-segregated environment can provide female ABI (acquired brain injury) survivors with a fertile scene for identity enhancement and offer unique opportunities for collective identity development. Sociolinguistic interactional analysis revealed four types of positive identity work undertaken within the group: constructing competent selves; tempering the threat of loss and impairment; resisting infantilisation and delegitimisation; and asserting a collective gender identity. This identity work was facilitated by specific programme attributes and activities and contributed to the global project of decentring disability and destigmatising impairments and losses. We call for increased attention to identity issues in brain injury rehabilitation and argue that gender-segregated programming can provide a unique space for female survivors to construct empowering individual and collective identities after injury.  相似文献   
5.
6.
7.
8.
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   
9.
10.
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