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   25430篇
  免费   1321篇
  国内免费   136篇
耳鼻咽喉   226篇
儿科学   547篇
妇产科学   302篇
基础医学   3135篇
口腔科学   664篇
临床医学   1742篇
内科学   6573篇
皮肤病学   960篇
神经病学   1750篇
特种医学   719篇
外科学   4476篇
综合类   90篇
一般理论   2篇
预防医学   588篇
眼科学   490篇
药学   1558篇
中国医学   57篇
肿瘤学   3008篇
  2023年   148篇
  2022年   358篇
  2021年   579篇
  2020年   307篇
  2019年   407篇
  2018年   520篇
  2017年   440篇
  2016年   533篇
  2015年   500篇
  2014年   666篇
  2013年   778篇
  2012年   1314篇
  2011年   1391篇
  2010年   912篇
  2009年   716篇
  2008年   1230篇
  2007年   1317篇
  2006年   1395篇
  2005年   1387篇
  2004年   1280篇
  2003年   1257篇
  2002年   1229篇
  2001年   719篇
  2000年   738篇
  1999年   702篇
  1998年   288篇
  1997年   213篇
  1996年   203篇
  1995年   181篇
  1994年   136篇
  1993年   153篇
  1992年   439篇
  1991年   391篇
  1990年   399篇
  1989年   420篇
  1988年   378篇
  1987年   330篇
  1986年   334篇
  1985年   285篇
  1984年   228篇
  1983年   170篇
  1982年   83篇
  1979年   156篇
  1978年   108篇
  1977年   117篇
  1974年   104篇
  1973年   79篇
  1972年   97篇
  1971年   86篇
  1970年   90篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
Context: We sought to describe our experience with the Hybrid Assistive Limb® (HAL®) for active knee extension and voluntary ambulation with remaining muscle activity in a patient with complete paraplegia after spinal cord injury.

Findings: A 30-year-old man with complete paraplegia used the HAL® for 1 month (10 sessions) using his remaining muscle activity, including hip flexor and upper limb activity. Electromyography was used to evaluate muscle activity of the gluteus maximus, tensor fascia lata, quadriceps femoris, and hamstring muscles in synchronization with the Vicon motion capture system. A HAL® session included a knee extension session with the hip flexor and voluntary gait with upper limb activity. After using the HAL® for one month, the patient’s manual muscle hip flexor scores improved from 1/5 to 2/5 for the right and from 2/5 to 3/5 for the left knee, and from 0/5 to 1/5 for the extension of both knees.

Conclusion/clinical relevance: Knee extension sessions with HAL®, and hip flexor and upper-limb-triggered HAL® ambulation seem a safe and feasible option in a patient with complete paraplegia due to spinal cord injury.  相似文献   

6.
7.
8.
9.
Adolescence is a vulnerable period for developing anxiety-related mental disorders such as post-traumatic stress disorder (PTSD), which requires a long-term course of therapy when a traumatic event has been experienced during childhood. However, the biological mechanism underlying these age-dependent characteristics remains unclear. In the present study, we used early adolescent, late adolescent and adult (4-, 8-, and 15-week old) male mice to examine age differences in fear memory, fear extinction, and spontaneous recovery of fear. We also measured the activation of extracellular signal-regulated kinase (ERK) 2 in the dorsal hippocampus (dHip) and the basolateral amygdala (BLA) following a spontaneous recovery test. Our major findings were as follows: (1) early adolescent and adult mice did not recover the fear response; only late adolescent mice recovered the fear response. (2) The ERK2 in the dHip was more activated after the spontaneous recovery test in late adolescent mice than in adult mice, and the ERK2 in the BLA was more activated after the spontaneous recovery test in adult mice than in late adolescent mice. These results suggest that there exists a unique period in which spontaneous recovery occurs and that these late adolescent behavioral signatures may be related to alteration in the ERK2 phosphorylation in the dHip and BLA.  相似文献   
10.
Hidroacanthoma simplex (HAS) is a rare benign eccrine adnexal tumor. HAS is sometimes clinically or pathologically misdiagnosed as squamous cell carcinoma in situ (Bowen's disease; BD), seborrheic keratosis (SK) or other adnexal tumor. To date, there has never been a report focusing on dermoscopic features to distinguish HAS from BD and SK. We found the following dermoscopic findings to be characteristic of HAS: fine black dots/globules (75% of cases) and fine scales arranged annularly (100% of cases). In contrast, glomerular vessels, which are typically observed in BD, were not seen in any of the four cases. Cerebriform appearance and milia‐like cysts, which are typically observed in SK, were also not seen in any of the four cases. The existence of “scattered fine black dots/globules” and “fine scales arranged annularly”, and the absence of the glomerular vessels, may contribute to precise diagnosis of HAS. Even though HAS resembles BD or SK clinically, it can be distinguished from these by the characteristic dermoscopic features.  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