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   195931篇
  免费   33966篇
  国内免费   2572篇
耳鼻咽喉   5536篇
儿科学   6802篇
妇产科学   3558篇
基础医学   9501篇
口腔科学   2043篇
临床医学   31439篇
内科学   56622篇
皮肤病学   8205篇
神经病学   20281篇
特种医学   7418篇
外科学   44688篇
综合类   610篇
现状与发展   72篇
一般理论   59篇
预防医学   12491篇
眼科学   3949篇
药学   3884篇
  6篇
中国医学   92篇
肿瘤学   15213篇
  2024年   914篇
  2023年   5671篇
  2022年   2508篇
  2021年   5212篇
  2020年   7240篇
  2019年   3842篇
  2018年   9254篇
  2017年   8550篇
  2016年   9727篇
  2015年   9884篇
  2014年   17274篇
  2013年   18013篇
  2012年   9487篇
  2011年   9448篇
  2010年   12275篇
  2009年   15889篇
  2008年   8586篇
  2007年   6797篇
  2006年   9092篇
  2005年   6205篇
  2004年   5212篇
  2003年   3959篇
  2002年   3738篇
  2001年   3966篇
  2000年   3139篇
  1999年   3408篇
  1998年   3957篇
  1997年   3700篇
  1996年   3552篇
  1995年   3375篇
  1994年   2057篇
  1993年   1675篇
  1992年   1441篇
  1991年   1473篇
  1990年   1111篇
  1989年   1248篇
  1988年   1068篇
  1987年   897篇
  1986年   931篇
  1985年   764篇
  1984年   604篇
  1983年   566篇
  1982年   544篇
  1981年   439篇
  1980年   386篇
  1979年   328篇
  1978年   347篇
  1977年   420篇
  1975年   289篇
  1972年   310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