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   25615篇
  免费   5928篇
  国内免费   133篇
耳鼻咽喉   724篇
儿科学   686篇
妇产科学   787篇
基础医学   924篇
口腔科学   2723篇
临床医学   4678篇
内科学   5738篇
皮肤病学   513篇
神经病学   2213篇
特种医学   1139篇
外科学   4453篇
综合类   99篇
现状与发展   12篇
一般理论   5篇
预防医学   3186篇
眼科学   448篇
药学   460篇
中国医学   27篇
肿瘤学   2861篇
  2024年   166篇
  2023年   1131篇
  2022年   455篇
  2021年   877篇
  2020年   1305篇
  2019年   655篇
  2018年   1490篇
  2017年   1410篇
  2016年   1611篇
  2015年   1687篇
  2014年   2155篇
  2013年   2584篇
  2012年   1084篇
  2011年   1029篇
  2010年   1480篇
  2009年   2064篇
  2008年   914篇
  2007年   667篇
  2006年   815篇
  2005年   583篇
  2004年   459篇
  2003年   408篇
  2002年   376篇
  2001年   435篇
  2000年   328篇
  1999年   423篇
  1998年   523篇
  1997年   502篇
  1996年   552篇
  1995年   407篇
  1994年   318篇
  1993年   273篇
  1992年   215篇
  1991年   194篇
  1990年   186篇
  1989年   201篇
  1988年   162篇
  1987年   169篇
  1986年   141篇
  1985年   133篇
  1984年   107篇
  1983年   120篇
  1982年   103篇
  1981年   86篇
  1980年   70篇
  1979年   54篇
  1978年   55篇
  1977年   66篇
  1976年   49篇
  1975年   58篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.

Background

Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.

Objectives

To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.

Methods

Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.

Results

Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.

Conclusions

These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study.  相似文献   
4.
5.
6.
7.
8.

Introduction

In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.

Methods

We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.

Results

A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.

Conclusion

The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department.  相似文献   
9.
The intention of this article is to introduce the reader to the Transograph from a historical perspective. The technical data presented are intended to help the reader understand the design of this unique instrument and how it was programmed, but will not provide the reader a thorough understanding of this philosophy. The article seeks neither to defend nor criticize the principles of Transographics.  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