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   158350篇
  免费   31849篇
  国内免费   2404篇
耳鼻咽喉   5264篇
儿科学   5663篇
妇产科学   2526篇
基础医学   4020篇
口腔科学   1770篇
临床医学   27387篇
内科学   48629篇
皮肤病学   7521篇
神经病学   15699篇
特种医学   6674篇
外科学   42106篇
综合类   371篇
现状与发展   72篇
一般理论   4篇
预防医学   7717篇
眼科学   3486篇
药学   1321篇
中国医学   14篇
肿瘤学   12359篇
  2024年   753篇
  2023年   5116篇
  2022年   1496篇
  2021年   3174篇
  2020年   6067篇
  2019年   2213篇
  2018年   7448篇
  2017年   7378篇
  2016年   8469篇
  2015年   8449篇
  2014年   15587篇
  2013年   15752篇
  2012年   5688篇
  2011年   5690篇
  2010年   10438篇
  2009年   14341篇
  2008年   5979篇
  2007年   4228篇
  2006年   6710篇
  2005年   3952篇
  2004年   3236篇
  2003年   2210篇
  2002年   2306篇
  2001年   4045篇
  2000年   3289篇
  1999年   3464篇
  1998年   3724篇
  1997年   3528篇
  1996年   3404篇
  1995年   3284篇
  1994年   2002篇
  1993年   1615篇
  1992年   1601篇
  1991年   1646篇
  1990年   1274篇
  1989年   1398篇
  1988年   1211篇
  1987年   1095篇
  1986年   1086篇
  1985年   893篇
  1984年   691篇
  1983年   643篇
  1982年   586篇
  1981年   478篇
  1980年   421篇
  1979年   440篇
  1978年   423篇
  1977年   480篇
  1975年   339篇
  1972年   383篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
84.
85.
86.
87.
88.
89.
90.
BACKGROUND: Endovascular radiofrequency obliteration has been used since 1998 as an alternative to conventional vein stripping surgery for elimination of saphenous vein insufficiency. OBJECTIVE: To demonstrate the long-term efficacy of this treatment modality. METHODS: Data were prospectively collected in a multicenter ongoing registry. Only great saphenous vein above-knee treatments were included in this study. Eight hundred ninety patients (1,078 limbs) were treated prior to November 2003 at 32 centers. Clinical and duplex ultrasound follow-up was performed at 1 week, 6 months, and 1, 2, 3, and 4 years. RESULTS: Among 1,078 limbs treated, 858 were available for follow-up within 1 week, 446 at 6 months, 384 at 1 year, 210 at 2 years, 114 at 3 years, and 98 at 4 years. The vein occlusion rates were 91.0%, 88.8%, 86.2%, 84.2%, and 88.8%, respectively; the reflux-free rates were 91.0%, 89.3%, 86.2%, 86.0%, and 85.7%, respectively; and the varicose vein recurrence rates were 7.2%, 13.5%, 17.1%, 14.0%, and 21.4%, respectively, at each follow-up time point at 6 months, and 1, 2, 3, and 4 years. Patient symptom improvement persisted over 4 years. CONCLUSIONS: Endovascular temperature-controlled radiofrequency obliteration of saphenous vein reflux exhibits an enduring treatment efficacy clinically, anatomically, and hemodynamically up to 4 years following treatment.  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