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   21455篇
  免费   1223篇
  国内免费   114篇
耳鼻咽喉   184篇
儿科学   538篇
妇产科学   273篇
基础医学   2692篇
口腔科学   546篇
临床医学   1530篇
内科学   5304篇
皮肤病学   918篇
神经病学   1544篇
特种医学   630篇
外科学   3733篇
综合类   112篇
一般理论   2篇
预防医学   592篇
眼科学   535篇
药学   1265篇
中国医学   55篇
肿瘤学   2339篇
  2023年   125篇
  2022年   302篇
  2021年   532篇
  2020年   279篇
  2019年   373篇
  2018年   521篇
  2017年   403篇
  2016年   463篇
  2015年   430篇
  2014年   593篇
  2013年   684篇
  2012年   1046篇
  2011年   1061篇
  2010年   677篇
  2009年   539篇
  2008年   960篇
  2007年   1003篇
  2006年   1048篇
  2005年   1119篇
  2004年   1026篇
  2003年   950篇
  2002年   927篇
  2001年   691篇
  2000年   687篇
  1999年   655篇
  1998年   233篇
  1997年   174篇
  1996年   188篇
  1995年   142篇
  1994年   110篇
  1993年   123篇
  1992年   425篇
  1991年   367篇
  1990年   387篇
  1989年   404篇
  1988年   366篇
  1987年   326篇
  1986年   319篇
  1985年   271篇
  1984年   218篇
  1983年   168篇
  1982年   77篇
  1979年   149篇
  1978年   104篇
  1977年   109篇
  1974年   105篇
  1973年   83篇
  1972年   97篇
  1971年   85篇
  1970年   91篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
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   

5.
6.
7.
8.
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   
9.
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   
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