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   23449篇
  免费   1484篇
  国内免费   47篇
耳鼻咽喉   200篇
儿科学   734篇
妇产科学   756篇
基础医学   2939篇
口腔科学   329篇
临床医学   3780篇
内科学   4023篇
皮肤病学   211篇
神经病学   2400篇
特种医学   426篇
外科学   2153篇
综合类   280篇
一般理论   33篇
预防医学   3442篇
眼科学   371篇
药学   1331篇
中国医学   25篇
肿瘤学   1547篇
  2024年   15篇
  2023年   148篇
  2022年   201篇
  2021年   432篇
  2020年   307篇
  2019年   469篇
  2018年   558篇
  2017年   422篇
  2016年   474篇
  2015年   562篇
  2014年   784篇
  2013年   1164篇
  2012年   1700篇
  2011年   1843篇
  2010年   971篇
  2009年   874篇
  2008年   1579篇
  2007年   1726篇
  2006年   1609篇
  2005年   1598篇
  2004年   1580篇
  2003年   1444篇
  2002年   1428篇
  2001年   258篇
  2000年   176篇
  1999年   221篇
  1998年   274篇
  1997年   233篇
  1996年   168篇
  1995年   188篇
  1994年   163篇
  1993年   130篇
  1992年   125篇
  1991年   112篇
  1990年   89篇
  1989年   84篇
  1988年   77篇
  1987年   77篇
  1986年   65篇
  1985年   88篇
  1984年   73篇
  1983年   65篇
  1982年   67篇
  1981年   65篇
  1980年   44篇
  1979年   38篇
  1978年   28篇
  1977年   23篇
  1976年   16篇
  1967年   14篇
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
1.
2.
3.
4.
5.
Digestive Diseases and Sciences -  相似文献   
6.

Background

Current blunt cerebrovascular injury (BCVI) grading grossly differentiates injury characteristics such as luminal stenosis (LS) and aneurysmal disease. The effect of increasing degree of LS beyond the current BCVI grading scale on stroke formation is unknown.

Study Design

BCVI over a 3-year period were retrospectively reviewed. To investigate influence of LS beyond the BCVI grading scale within aneurysmal and non-aneurysmal BCVI, grade 2 BCVI were subdivided into BCVI with ≥ 25% and ≤ 50% LS and BCVI with > 50% and ≤ 99% LS. Grade 3 BCVI were subdivided into BCVI with pseudoaneurysm (PSA) without LS and BCVI with PSA and LS. We hypothesized increased LS beyond the current BCVI grade distinctions would be associated with higher rates of stroke formation.

Results

312 BCVI were included, of which 140 were carotid BCVI and 172 vertebral BCVI. Sixteen carotid BCVI underwent endovascular intervention (EI) and 19 suffered a stroke. In carotid BCVI stroke rates increased sequentially with BCVI grade except in grade 3. There was a stroke rate of 12% in grade 1 carotid BCVI, 18% in grade 2, 6% in grade 3, and 31% in grade 4. In subgroup analysis for grade 2 carotid BCVI, BCVI with > 50% and ≤ 99% LS had higher rates of stroke (22% vs. 15%, p?=?0.44) than BCVI with ≥ 25% and ≤ 50% LS. In subgroup analysis of grade 3 carotid BCVI, BCVI with PSA and LS had higher rates of stroke (9% vs. 4%, p?=?0.48) than BCVI with PSA without LS. Higher rates of EI in grade 2 carotid BCVI with > 50% and ≤ 99% LS (22% vs. 5%, p?=?0.14) and grade 3 carotid BCVI with PSA and LS (35% vs. 4%, p?=?0.01) were noted in subgroup analysis.

Conclusion

Higher percentage LS beyond the currently used BCVI grading scale has a non-significantly increased rate of stroke in both aneurysmal and non-aneurysmal BCVI. Grade 3 BCVI with PSA and LS seems to be a high-risk subgroup. Use of EI confounds modern measurement of stroke risk in higher LS BCVI.  相似文献   
7.

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   
8.
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