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   1994篇
  免费   108篇
  国内免费   30篇
耳鼻咽喉   79篇
儿科学   83篇
妇产科学   101篇
基础医学   116篇
口腔科学   85篇
临床医学   172篇
内科学   538篇
皮肤病学   18篇
神经病学   96篇
特种医学   59篇
外科学   467篇
综合类   38篇
预防医学   48篇
眼科学   88篇
药学   54篇
中国医学   1篇
肿瘤学   89篇
  2024年   1篇
  2023年   12篇
  2022年   23篇
  2021年   38篇
  2020年   29篇
  2019年   47篇
  2018年   54篇
  2017年   41篇
  2016年   80篇
  2015年   122篇
  2014年   115篇
  2013年   134篇
  2012年   159篇
  2011年   163篇
  2010年   99篇
  2009年   75篇
  2008年   162篇
  2007年   168篇
  2006年   152篇
  2005年   153篇
  2004年   136篇
  2003年   77篇
  2002年   49篇
  2001年   10篇
  2000年   5篇
  1999年   5篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1987年   1篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1974年   1篇
  1971年   1篇
排序方式: 共有2132条查询结果,搜索用时 343 毫秒
41.
42.
43.
The aim of this prospective experimental study was to evaluate the effect of light-emitting diode (LED) photobiomodulation therapy (LPT) on the stability of immediately loaded miniscrews under different force levels, as assessed by resonance frequency analysis (RFA). Sixty titanium orthodontic miniscrews with a length of 8 mm and a diameter of 1.4 mm were implanted into cortical bone by closed flap technique in each proximal tibia of 15 New Zealand white adult male rabbits (n = 30). The animals were randomly divided into irradiated and control groups under different force levels (0, 150, and 300 cN). OsseoPulse? LED device (Biolux Research Ltd.) 618 nm wavelength and 20 mW/cm(2) output power irradiation (20 minutes/day) was applied to the miniscrews for 10 days. The RFA records were performed at miniscrew insertion session (T1) and 21 days after surgery (T2). Wilcoxon and Mann-Whitney U-tests were used for statistical evaluation at P < 0.005 level. It was found that initial primer stability of all miniscrews was similar in all groups at the start of the experimental procedure. Statistically significant differences were found for changes in implant stability quotient (ISQ) values between LED-photobiomodulated group and the control (0 cN, P = 0.001; 150 cN, P < 0.001; and 300 cN, P < 0.001). Significant increase was found in ISQ values of LPT applied miniscrews under 0 cN (+11.63 ISQ), 150 cN (+10.50 ISQ), and 300 cN (+7.00 ISQ) force during observation period. By the increase of force levels, it was determined that ISQ values decreased in non-irradiated control miniscrews. Within the limits of this in vivo study, the present RFA findings suggest that LPT might have a favourable effect on healing and attachment of titanium orthodontic miniscrews.  相似文献   
44.
Background: The level and activity of indoleamine 2,3-dioxygenase (IDO) and the concentrations of L-tryptophan and its metabolite L-kynurenine were determined in association with various renal diseases. However, there have been no data regarding these parameters in patients on peritoneal dialysis compared to those undergoing hemodialysis or kidney transplantation.

Methods: This study investigated the level and activity of IDO and determined oxidative balance by calculating the total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI). We enrolled 60 kidney disease patients, including 20 on peritoneal dialysis (PD group), 19 on hemodialysis (HD group), and 21 with kidney transplantation (KT group), as well as 21 control group.

Results: IDO levels were increased in the PD, HD, and KT groups compared to the control group. The concentration of kynurenine was significantly increased in the PD group compared to the other groups (p?p?p?Conclusion: The results showed that IDO levels were increased in peritoneal dialysis and hemodialysis patients and in renal transplant recipients, while oxidative stress was found to be related to IDO activity and was most increased in the patients on peritoneal dialysis.  相似文献   
45.
46.
47.
48.
49.
OBJECTIVE: To increase retention of overdentures in cleft palate patients by means of heightened telescopic copings with a newly designed attachment. In this study, a "precision attachment" is described to develop the stability and retention of telescopic overdentures. CASE: A cleft palate patient was treated with a newly designed overdenture. Intraoral examination revealed poor tooth structure and retention. Therefore, a new semiprecision attachment was designed in order to increase retention and stabilization. CONCLUSION: The patient's tolerance was increased with the new overdenture.  相似文献   
50.
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