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   2380篇
  免费   141篇
  国内免费   7篇
耳鼻咽喉   60篇
儿科学   52篇
妇产科学   136篇
基础医学   176篇
口腔科学   74篇
临床医学   237篇
内科学   528篇
皮肤病学   43篇
神经病学   145篇
特种医学   127篇
外国民族医学   1篇
外科学   397篇
综合类   45篇
预防医学   122篇
眼科学   113篇
药学   170篇
中国医学   7篇
肿瘤学   95篇
  2023年   18篇
  2022年   20篇
  2021年   71篇
  2020年   42篇
  2019年   62篇
  2018年   88篇
  2017年   55篇
  2016年   71篇
  2015年   86篇
  2014年   113篇
  2013年   129篇
  2012年   204篇
  2011年   192篇
  2010年   120篇
  2009年   112篇
  2008年   175篇
  2007年   159篇
  2006年   175篇
  2005年   165篇
  2004年   132篇
  2003年   98篇
  2002年   75篇
  2001年   29篇
  2000年   23篇
  1999年   22篇
  1998年   14篇
  1997年   12篇
  1996年   11篇
  1994年   2篇
  1992年   6篇
  1991年   3篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
  1979年   1篇
  1975年   2篇
  1974年   3篇
  1973年   4篇
  1972年   2篇
  1971年   3篇
  1970年   3篇
  1969年   5篇
  1968年   2篇
  1930年   1篇
排序方式: 共有2528条查询结果,搜索用时 17 毫秒
1.
Aim: The aim of this study was to determine the prevalence of childhood psychopathologies in Turkey.

Method: A nation-wide, randomly selected, representative population of 5830 children (6–13 years-old) enrolled as a 2nd,3rd or 4th grade student in 30 cities were evaluated for presence of a psychiatric or mental disorder by a Sociodemographic Form, Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version (K-SADS-PL), and DSM-IV-Based Screening Scale for Disruptive Behavior Disorders in Children and Adolescents scales. Impairment criterion was assessed via a 3 point-Likert scale by the parent and the teacher independently.

Results: Overall prevalence of any psychopathology was 37.6% without impairment criterion, and 17.1% with impairment criterion. Attention-deficit hyperactivity disorder was the most frequent diagnosis, followed by anxiety (19.5% and 16.7% without impairment, 12.4% and 5.3% with impairment, respectively). Lower education level and presence of a physical or psychiatric problem of the parents were independent predictors of any psychopathology of the offspring.

Conclusion: This is the largest and most comprehensive epidemiological study to determine the prevalence of psychopathologies in children and adolescents in Turkey. Our results partly higher than, and partly comparable to previous national and international studies. It also contributes to the literature by determining the independent predictors of psychopathologies in this age group.  相似文献   

2.
3.
4.
International Journal of Diabetes in Developing Countries - Although monogenic diabetes accounts for a small proportion of diabetes cases, accurate diagnosis may significantly change treatment....  相似文献   
5.

Background

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the “gold standard” of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons.

Methods

Several formulations of silicone were utilized for the design and fabrication of a model which realizes the hierarchical structure of peripheral nerves. The mechanical properties were characterized via the Universal Testing Machine; the damage caused by the needle on the entry sites was assessed through scanning electron microscopy (SEM).

Results

Mechanical properties of the formulations of silicone were tested to mimic human peripheral nerves. A formulation with 83.3?wt% silicone oil and 0.1?wt% cotton fiber was chosen to be used as nerve fascicles. Both 83.3?wt% silicone oil with cotton fiber and 66.6?wt% silicone oil without fiber provided a microsuturing response similar to that of epineurium at a wall thickness of 1?mm. SEM also confirmed that the entry of the needle did not introduce significant holes at the microsuturing sites.

Conclusions

The proposed peripheral nerve model mimicked human tissues mechanically and cosmetically, and a simulation of the repair of a fifth-degree nerve injury was achieved.  相似文献   
6.
Inflammation in the liver is an extraintestinal manifestation that is frequently seen during inflammatory bowel diseases (IBD). The authors investigated histopathologycal, ultrastructural and antioxidant effects of dexmedetomidine (Dex) on liver during trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease. Thirty-two BALB/c mice were divided (n?=?8) as follows: control; Dex (dexmedetomidine) (30?μg/kg) for 6 days; TNBS 150?μL, TNBS?+?ethanol (50% w/v) intrarectally; TNBS?+?Dex. The histopathological and ultrastructural changes were evaluated. The levels of malondialdehyde (MDA), activity of antioxidant enzymes (GPx and SOD) were measured in liver tissue. Induction of colitis induced histopathological and ultrastructural changes of damage in liver. Those changes were markedly reduced in the TNBS?+?Dex group and that reduction was even significant in comparison to the TNBS group. MDA levels were significantly higher in the TNBS group and dexmedetomidine significantly elevated SOD levels in the TNBS?+?Dex group. These results suggest that the administration of dexmedetomidine reduces the histopathological and ultrastructural damage and increases the defense capacity against oxidative damage on liver in this IBD mice model.  相似文献   
7.
8.
9.
10.
PURPOSE: The purpose of this project was to study the effect of chitosan bead encapsulating calcium sulfate, which provides a sustained release of chitosan and calcium sulfate after implantation, on early bony consolidation in distraction osteogenesis of a dog model. MATERIALS AND METHODS: Forty-five dogs were used for this study. An external distraction device was applied to the mandibular body after a vertical osteotomy and mandibular distraction was initiated 5 days after the operation at a rate of 1 mm/day up to a 10-mm distraction. The experimental group was divided into a control group (I), hyaluronic acid group (II), chitosan group (III), calcium sulfate group (IV), and chitosan bead encapsulating calcium sulfate group (V). Normal saline was injected in group I. In group II, 1 mL of hyaluronic acid solution was injected into the distracted region. In group III, 1 mL of injectable solution of chitosan mixed with hyaluronic acid was implanted. In group IV, 1 mL of injectable solution of calcium sulfate mixed with hyaluronic acid was implanted. In group V, an injectable form of powdered chitosan bead encapsulating calcium sulfate mixed with 1 mL volume of hyaluronic acid was implanted. RESULTS: Bone mineral density was 12% of the contralateral normal mandible at 3 weeks, 23.4% at 6 weeks in group I, 15% at 3 weeks, 29.1% at 6 weeks in group II, 16% at 3 weeks and 32% at 6 weeks in group III, 30.4% at 3 weeks and 52.8% at 6 weeks in group IV, and 33.6% at 3 weeks and 55% at 6 weeks in group V with statistical significance (P < .005). The mean 3-point failure load was compared with the intact contralateral mandible and noted to be 12% in the control group, 16% in group II, 18% in group III, 34.3% in group IV, and 31.7% in group V. Difference of mean percentages between one group and another was statistically significant (P < .005). In the histologic findings, new bone was generated in all groups. In groups IV and V, the formation of active woven bone was observed throughout the distracted region at 6 weeks. The amount of new bone formation in the distracted zone was in the order of group IV and V, III and II, and the control group. CONCLUSIONS: These findings suggest that chitosan bead encapsulating calcium sulfate appears to facilitate early bony consolidation in distraction osteogenesis.  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