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   10853篇
  免费   1065篇
  国内免费   74篇
耳鼻咽喉   84篇
儿科学   363篇
妇产科学   159篇
基础医学   1589篇
口腔科学   357篇
临床医学   1180篇
内科学   1996篇
皮肤病学   242篇
神经病学   766篇
特种医学   635篇
外科学   1389篇
综合类   291篇
一般理论   4篇
预防医学   991篇
眼科学   199篇
药学   724篇
中国医学   14篇
肿瘤学   1009篇
  2021年   143篇
  2020年   90篇
  2019年   123篇
  2018年   158篇
  2017年   130篇
  2016年   140篇
  2015年   163篇
  2014年   207篇
  2013年   385篇
  2012年   443篇
  2011年   475篇
  2010年   292篇
  2009年   279篇
  2008年   401篇
  2007年   511篇
  2006年   446篇
  2005年   443篇
  2004年   431篇
  2003年   394篇
  2002年   375篇
  2001年   316篇
  2000年   339篇
  1999年   307篇
  1998年   176篇
  1997年   179篇
  1996年   151篇
  1995年   153篇
  1994年   115篇
  1993年   139篇
  1992年   287篇
  1991年   264篇
  1990年   230篇
  1989年   268篇
  1988年   199篇
  1987年   225篇
  1986年   202篇
  1985年   230篇
  1984年   143篇
  1983年   137篇
  1982年   113篇
  1981年   104篇
  1980年   105篇
  1979年   144篇
  1978年   94篇
  1977年   104篇
  1976年   104篇
  1975年   88篇
  1973年   93篇
  1972年   92篇
  1971年   92篇
排序方式: 共有10000条查询结果,搜索用时 780 毫秒
1.

Objective

Successful weight loss interventions for African-Americans adolescents are lacking. Cognitive-behavioral interventions seek to develop weight loss skills (e.g., counting calories, goal setting, managing one's environment). Little is known about how well adolescents implement such skills in their daily lives. Study aims were to (1) examine weight loss skills utilization at midpoint and end of a 6-month cognitive-behavioral/motivational interviewing weight loss sequential multiple assignment randomized trial (SMART), and (2) determine if greater skill utilization predicted weight loss at treatment end and 3 months post-treatment.

Method

One hundred and eighty six African-Americans adolescents with obesity and their caregiver were first randomly assigned to complete 3 months of cognitive-behavioral and motivational interviewing family-based weight loss treatment in their home or in the research office (Phase 1). Nonresponders (i.e., those who lost < 3% of initial weight, n?=?161) were rerandomized to 3 months of continued skills training (n?=?83) or contingency management (n?=?78) for Phase 2; responders were allocated to 3 months of relapse prevention (n?=?20). Adolescents’ frequency of weight loss skills utilization was assessed via questionnaire at treatment midpoint and end.

Results

Higher treatment attendance was associated with better skill utilization. Higher skill utilization was associated with more weight loss at treatment end, whereas higher baseline confidence was associated with more weight loss at follow-up.

Conclusions

This study indicates the importance of attending weight loss intervention sessions to develop and strengthen weight loss skills in African-American adolescents with obesity, and strengthening confidence to use such skills for continued weight loss.  相似文献   
2.
3.
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security.  相似文献   
4.
5.
6.
7.
8.
Objective. The safety and efficacy of intrathecal (IT) ziconotide was studied in a randomized, double‐blind, placebo‐controlled trial. Materials and Methods. Patients (169 ziconotide, 86 placebo) with severe chronic nonmalignant pain unresponsive to conventional therapy and a visual analog scale of pain intensity (VASPI score) ≥ 50 mm were treated over a 6‐day period in an inpatient hospital setting. Initial starting dose was 0.4 µg/hour and was titrated to analgesia or intolerance (maximum dose 7.0 µg/hour). The starting and maximum doses were reduced to 0.1 µg/hour and 2.4 µg/hour, respectively, due to adverse events (AEs). Results. The mean percent reduction in VASPI score from baseline was 31.2% and 6.0% for ziconotide‐ and placebo‐treated patients, respectively (p ≤ 0.001). During the initial titration phase, a significantly greater percentage of patients in the ziconotide group compared to the placebo group reported AEs, including abnormal gait, amblyopia, dizziness, nausea, nystagmus, pain, urinary retention, and vomiting. Conclusion. Ziconotide provided significant analgesia in patients for whom conventional therapy failed. However, there was a considerable incidence of ziconotide‐associated AEs due to the rapid titration and high doses administered.  相似文献   
9.
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