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   150444篇
  免费   31213篇
  国内免费   2392篇
耳鼻咽喉   5170篇
儿科学   5373篇
妇产科学   2403篇
基础医学   3047篇
口腔科学   1628篇
临床医学   26601篇
内科学   47151篇
皮肤病学   7422篇
神经病学   14802篇
特种医学   6324篇
外科学   40961篇
综合类   234篇
现状与发展   72篇
一般理论   2篇
预防医学   6954篇
眼科学   3331篇
药学   894篇
中国医学   8篇
肿瘤学   11672篇
  2024年   684篇
  2023年   4784篇
  2022年   1194篇
  2021年   3070篇
  2020年   6008篇
  2019年   2151篇
  2018年   7352篇
  2017年   7312篇
  2016年   8377篇
  2015年   8377篇
  2014年   15440篇
  2013年   15580篇
  2012年   5371篇
  2011年   5379篇
  2010年   10299篇
  2009年   14191篇
  2008年   5717篇
  2007年   3936篇
  2006年   6411篇
  2005年   3710篇
  2004年   2985篇
  2003年   1977篇
  2002年   2048篇
  2001年   3858篇
  2000年   3056篇
  1999年   3256篇
  1998年   3642篇
  1997年   3460篇
  1996年   3359篇
  1995年   3213篇
  1994年   1946篇
  1993年   1562篇
  1992年   1406篇
  1991年   1440篇
  1990年   1079篇
  1989年   1200篇
  1988年   1046篇
  1987年   874篇
  1986年   907篇
  1985年   737篇
  1984年   551篇
  1983年   527篇
  1982年   517篇
  1981年   403篇
  1980年   363篇
  1979年   314篇
  1978年   342篇
  1977年   403篇
  1975年   280篇
  1972年   307篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
BACKGROUND: Previous data indicate that injections of autologous fibroblasts increase collagen formation, accompanied by a concomitant increase in thickness and density of dermal collagen. OBJECTIVE: The purpose of this study was to determine efficacy and side effects of autologous living fibroblast injections versus placebo in a randomized Phase III trial for the treatment of various facial contour defects. METHODS: This was a double-blind, randomized comparison of injectable living autologous fibroblast cells and placebo for the treatment of facial contour defects (N=215). Live fibroblasts (20 million/mL) or placebo (the transport medium without living cells) were given as three doses administered at 1- to 2-week intervals. Efficacy evaluations were performed 1, 2, 4, 6, 9, and 12 months after the first injection. RESULTS: Living fibroblasts produced statistically significantly greater improvements in dermal deformities and acne scars than did placebo. The difference between live fibroblast injections and placebo achieved statistical significance at 6 months (p<.0001). At 9- and 12-month follow-up, live fibroblast-treated patients continued to demonstrate benefit from treatment with response rates of 75.0 and 81.6%, respectively. No serious treatment-related adverse events were reported. CONCLUSIONS: Our results indicate that autologous fibroblast injections can safely and effectively produce improvements in rhytids, acne scars, and other dermal defects continuing for at least 12 months after injection.  相似文献   
82.
83.
Treatment of traumatically intruded teeth is based largely on empirical clinical experience rather than on scientific data. The aim of this qualitative meta-analysis was to provide an evidence base to evaluate the orthodontic repositioning approach. In a MEDLINE search of the literature in English, 14 reported patients involving 22 teeth were found to have been treated by this modality. Additionally, 3 new patients, involving 9 intruded teeth and presented herein, were combined to form a total study sample of 17 subjects (7 girls, 10 boys, aged 8.9 +/- 1.2 years). Orthodontic extrusive forces were applied in the immediate posttrauma period (up to 3 months), with a variety of orthodontic appliances. Repositioning was achieved for 90.3% of the affected teeth but failed in 9.7% because of inflammatory resorption (2 teeth) or a misdiagnosis of root fracture (1 tooth). Early complications included loss of pulp vitality and external root resorption. All intruded teeth with closed root apices lost their vitality regardless of the degree of intrusion, whereas among those with incomplete apices, 45.5% that had been moderately intruded remained vital. External resorption was encountered in 54.8% of the teeth. Loss of marginal bone support was rarely encountered. Late complications included inflammatory root resorption in teeth with closed apices, in which endodontic treatment was not initially performed, and obliteration of the pulp tissue in teeth that remained vital. The results show that this method is superior to other treatment alternatives.  相似文献   
84.
85.
86.
87.
88.
89.
90.
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