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   59332篇
  免费   6504篇
  国内免费   4248篇
耳鼻咽喉   731篇
儿科学   792篇
妇产科学   654篇
基础医学   5623篇
口腔科学   1359篇
临床医学   7403篇
内科学   7321篇
皮肤病学   562篇
神经病学   2431篇
特种医学   2287篇
外国民族医学   21篇
外科学   5703篇
综合类   13135篇
现状与发展   12篇
一般理论   4篇
预防医学   4948篇
眼科学   1269篇
药学   7107篇
  93篇
中国医学   4485篇
肿瘤学   4144篇
  2024年   232篇
  2023年   1055篇
  2022年   2290篇
  2021年   3387篇
  2020年   2617篇
  2019年   1925篇
  2018年   2012篇
  2017年   2000篇
  2016年   1797篇
  2015年   2954篇
  2014年   3558篇
  2013年   3646篇
  2012年   5135篇
  2011年   5386篇
  2010年   4152篇
  2009年   3485篇
  2008年   3717篇
  2007年   3695篇
  2006年   3329篇
  2005年   2754篇
  2004年   2203篇
  2003年   1995篇
  2002年   1725篇
  2001年   1273篇
  2000年   942篇
  1999年   654篇
  1998年   358篇
  1997年   347篇
  1996年   256篇
  1995年   206篇
  1994年   192篇
  1993年   120篇
  1992年   125篇
  1991年   102篇
  1990年   112篇
  1989年   67篇
  1988年   56篇
  1987年   49篇
  1986年   36篇
  1985年   18篇
  1984年   24篇
  1983年   18篇
  1982年   6篇
  1981年   8篇
  1979年   8篇
  1978年   6篇
  1975年   5篇
  1973年   9篇
  1968年   4篇
  1966年   4篇
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
11.
12.
13.
14.
Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019  相似文献   
15.
16.
17.
目的 探讨糖尿病前期的中医证型及证素分布特点。方法 检索中国知网、万方及维普三大数据库中收录的自建库以来有关糖尿病前期证型的临床研究文献,对中医证型进行规范整理,建立数据库,提取证素,运用数据挖掘技术中的关联分析、聚类分析探究证素分布规律。结果 共纳入10篇文献,总有效病例1620例,证型经规范处理后整理为18个,主要证型为脾虚痰湿证。共提取证素13个,主要病位证素为脾,主要病性证素为气虚、湿和痰,关联分析显示脾—湿支持度和置信度最高,聚类分析结果可得到3个聚类组。结论 糖尿病前期病位在脾,气虚、脾、痰、湿是常见证素,临床诊治糖尿病前期应注重从脾论治,需辨证施治。  相似文献   
18.
19.

Aim

Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.

Materials and methods

Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.

Results

LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.

Conclusion

Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC.  相似文献   
20.
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