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   412篇
  免费   18篇
耳鼻咽喉   32篇
儿科学   9篇
妇产科学   3篇
基础医学   70篇
口腔科学   6篇
临床医学   35篇
内科学   61篇
皮肤病学   6篇
神经病学   36篇
特种医学   13篇
外科学   61篇
综合类   7篇
一般理论   1篇
预防医学   29篇
眼科学   1篇
药学   25篇
肿瘤学   35篇
  2023年   4篇
  2022年   5篇
  2021年   10篇
  2020年   6篇
  2019年   6篇
  2018年   8篇
  2017年   8篇
  2016年   7篇
  2015年   13篇
  2014年   17篇
  2013年   19篇
  2012年   32篇
  2011年   38篇
  2010年   24篇
  2009年   24篇
  2008年   35篇
  2007年   33篇
  2006年   23篇
  2005年   17篇
  2004年   21篇
  2003年   23篇
  2002年   10篇
  2001年   3篇
  2000年   3篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1992年   3篇
  1990年   1篇
  1988年   1篇
  1987年   4篇
  1984年   3篇
  1980年   1篇
  1977年   3篇
  1976年   2篇
  1975年   2篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1970年   2篇
  1961年   1篇
排序方式: 共有430条查询结果,搜索用时 15 毫秒
51.

Background  

Research on the long-term effects of Type A behavior and its components in the prediction of physical activity in adulthood is scarce and there is a lack of prospective data that are able to show such an association.  相似文献   
52.
53.
We report on 3 patients with the cardio-faciocutaneous (CFC) syndrome. Each of them was a sporadic case in the family. The severity of the psychomotor retardation varied from mild to severe. Skin manifestations were often minimal, but each patient had abnormally curly and brittle hair. A skin biopsy from one of the patients showed vellus hair cysts filled with keratin, and the hair follicles were surrounded by unusually thick fibrotic sheaths. © 1992 Wiley-Liss, Inc.  相似文献   
54.

Purpose

Incidental durotomy is one of the most common complications in lumbar spine surgery. There are conflicting reports whether a dural lesion is associated with an inferior outcome after lumbar decompression. This study analyzed the effect of incidental durotomy in this specific group of patients (Dura+) and compared the results with the remaining cohort without dural laceration (Dura?).

Methods

This prospective multi-center study included 800 patients with lumbar spinal stenosis who underwent exclusive decompression surgery. All procedures were performed as part of a multi-center investigation at three highly specialized spine clinics. Outcome measures (ODI, EQ5D, VASback pain and VASleg pain) were obtained preoperatively as well as 3 and 12 months after surgery. The effect of an incidental durotomy on the clinical outcomes was analyzed statistically between the two cohorts.

Results

An intraoperative dura lesion was recorded in 6.5 % (n = 52/800) of all cases. Both cohorts (Dura+ and Dura?) did not reveal any differences regarding patient demographics, risk factors, or co-morbidities at baseline. The length of the hospital stay was significantly longer for the Dura+ cohort (8.0 vs. 6.4 days; p < 0.01). After 12 months, the Dura? cohort demonstrated a significantly greater improvement in VASback pain in comparison to the Dura+ cohort (Δ21.4 vs. Δ7.2 points; p < 0.05). The differences for the remaining outcome measures were not statistically significant (p > 0.05).

Conclusions

The results of this study reveal that an incidental durotomy was associated with a significant increase in the patient’s length of stay, and risk for re-intervention for the treatment of persisting CSF leakage. In contrast to previous reports which have investigated the effects of incidental durotomies on the clinical outcome after lumbar decompression surgery, our data further suggest a possible inferior outcome in terms of low back pain improvement in the Dura+ cohort, which became clinically apparent at the 12-month follow-up period. Future studies should investigate whether a more pronounced decompression required for adequate exposure and repair of a dural laceration may, ultimately, result in increased segmental instability and in clinically undesirable low back pain.
  相似文献   
55.
56.
Background: Understanding variation in physical activity (PA) and sleep is necessary to develop novel intervention strategies targeting adolescents’ health behaviors. We examined the extent to which PA and sleep vary by aspects of the physical environment. Participants: We performed a cross-sectional analysis of 669 adolescents in the Project Viva cohort. Methods: We estimated total PA, sleep duration, sleep efficiency, and sleep midpoint timing from wrist accelerometers. We used multivariable linear regression models and generalized estimated equations to assess associations of PA and sleep with season and daily weather conditions obtained from the National Oceanic and Atmospheric Administration archive. Results: Mean age was 12.9 (SD 0.6) years; 51% were female and 68% were white. Mean sleep duration was 466 (SD 42) min per night and total PA was 1,652 (SD 431) counts per min per day. Sleep midpoint time was 41 (95% CI: 27 to 54) min later in summer, 28 (95% CI: ?41 to ?14) min earlier in spring, and 29 (95% CI: ?43 to ?15) min earlier in autumn compared to winter. Higher temperature and longer day length both were associated with small reductions of nightly sleep duration. Adolescents were less physically active during winter and on rainy and short sunlight days. There was an inverse U-shaped relationship between PA and mean temperature. Conclusions: Season was associated with large changes in sleep timing, and smaller changes in other sleep and PA measurements. Given the importance of sleep and circadian alignment, future health behavioral interventions may benefit by targeting “season-specific” interventions.  相似文献   
57.
OBJECTIVE: To study the effects of cervical headgear treatment of Class II division 1 malocclusion on upper airway structures in children. MATERIALS AND METHODS: Forty children aged 9.1 (7.2-11.5) years with Class II division 1 malocclusion were treated using a cervical headgear as the only treatment appliance. The headgear consisted of a long outer bow bent 15 degrees upward and a large inner bow expanded 10 mm larger than the intermolar distance. Lateral cephalograms were taken before and after the treatment. Upper airway structures were estimated from the cephalograms. The results were compared to cross-sectional data of 80 age-matched controls with a Class I molar relationship. RESULTS: A Class I molar relationship was achieved in all treated children. The mean treatment time was 1.6 (0.3-3.1) years. The Class II malocclusion was accompanied by a similar or wider nasopharyngeal space than in the controls but narrower oro- and hypopharyngeal spaces. The retropalatal area was widened by the treatment (P < .05), whereas the rest of the oropharynx and hypopharynx remained narrower than in the controls. Before the treatment, the mandibular plane was in a more horizontal position than in the controls, but during the treatment, it rotated to a position similar to that of the controls. CONCLUSION: Class II division 1 malocclusion is associated with a narrower upper airway structure even without retrognathia. Headgear treatment is associated with an increase in the retropalatal airway space.  相似文献   
58.
59.
60.
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