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   53128篇
  免费   5668篇
  国内免费   1800篇
耳鼻咽喉   541篇
儿科学   1016篇
妇产科学   466篇
基础医学   4927篇
口腔科学   484篇
临床医学   6389篇
内科学   8751篇
皮肤病学   599篇
神经病学   11896篇
特种医学   1440篇
外国民族医学   11篇
外科学   3963篇
综合类   7287篇
现状与发展   6篇
一般理论   6篇
预防医学   2751篇
眼科学   1814篇
药学   4313篇
  25篇
中国医学   2239篇
肿瘤学   1672篇
  2024年   204篇
  2023年   1131篇
  2022年   1531篇
  2021年   2372篇
  2020年   2433篇
  2019年   2474篇
  2018年   2334篇
  2017年   2347篇
  2016年   2264篇
  2015年   2189篇
  2014年   3512篇
  2013年   4525篇
  2012年   2975篇
  2011年   3024篇
  2010年   2600篇
  2009年   2528篇
  2008年   2584篇
  2007年   2524篇
  2006年   2337篇
  2005年   2025篇
  2004年   1729篇
  2003年   1581篇
  2002年   1381篇
  2001年   1067篇
  2000年   908篇
  1999年   678篇
  1998年   622篇
  1997年   589篇
  1996年   524篇
  1995年   461篇
  1994年   374篇
  1993年   331篇
  1992年   318篇
  1991年   302篇
  1990年   209篇
  1989年   205篇
  1988年   177篇
  1987年   177篇
  1986年   147篇
  1985年   188篇
  1984年   139篇
  1983年   91篇
  1982年   102篇
  1981年   114篇
  1980年   57篇
  1979年   61篇
  1978年   44篇
  1977年   29篇
  1976年   26篇
  1975年   20篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual.  相似文献   
3.
4.
ObjectivesTo determine the prevalence of restless legs syndrome (RLS) and RLS-mimic conditions, the risk factors for RLS, and whether RLS contributes to functional impairment in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).MethodsADHD children and adolescents were prospectively studied at the outpatient psychiatric clinic. A trained registered nurse used the 2012 Revised International Restless Legs Syndrome Study Group diagnostic criteria to diagnose RLS. Sociodemographic data and medical records were reviewed. Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P) Thai version was used to identify association between RLS and 6 domains of function [family, school (learning), school (behavior), life skills, child self-concept, social activities, and risky activities].ResultsA total of 217 patients were included. Of those, 23 (11%) patients met the criteria for RLS, and 49 (23%) had RLS-mimic conditions. Those conditions included myalgia (30/49), habitual foot tapping (23/49), positional discomfort (20/49), leg ulcer/bruise (1/49), and arthralgia/arthritis (1/49). Binary logistic regression revealed first-degree relative having RLS symptom to be significantly associated with RLS in study patients (OR: 5.06, p < 0.01). Multivariate linear regression showed RLS to be independently associated with school (behavior) (Β = 1.18, p = 0.05) and life skills (Β = 2.36, p = 0.05) impairment.ConclusionsRLS was found to be common in ADHD children and adolescents. RLS-mimic conditions were found in two-thirds of patients who previously met 4 essential RLS criteria. First-degree relative with RLS symptom was associated with RLS, and RLS was associated with functional impairment in the life skills and school (behavior) domains.  相似文献   
5.
??Objective    To observe the effects of lithium chloride pretreatment on cognitive ability of aged rats after oral and maxillofacial surgery. Methods    A total of 48 aged male SD rats??18 ~ 20 months old??weight 550 ~ 700 g?? were bought from the Experimental Animal Center of China Medical University . These rats were randomly divided into three groups??including the normal control group??group C??n=16????surgery and anesthesia group??group O??n=16????and lithium chloride preconditioning group??group L??n=16??.Rats in each group were randomly divided into two parts??one part was given Morris water maze test three days after the surgery and its characteristics of behavior tested. Another part was decapitated 24 h after the surgery and extracted and the hippocampus brain separated at the same time. Test expression content of IL-1β GSK-3β p-GSK-3β??ser9??in the hippocampus by Elisa and Western blotting detection method respectively. Results    Morris water maze test showed that??the first day after surgery??latencies of group L and O were significantly longer than group C??compared with group C in swimming distance?? latency and swim distances of group L were shorter than group O. With the comparison of multiple analysis of variance??differences were statistically significant??P??0.05??. Groups L and O in the second day were slightly shortened compared to the first day??on the third day after surgery it has also improved over the second day. Space exploration experiments in rats showed that??the dwell time of group C was significantly longer in the platform quadrant and the frequency of crossing the platform also increased compared with groups L and O. In addition??group L and group O were higher in IL-β levels than group C??the difference being statistically significant by analysis of variance??P??0.05????but group L was significantly lower compared with group O??the difference being statistically significant??P??0.05??. The content of GSK-3β of three groups were of no significant difference??P > 0.05????but p-GSK-3β??ser9??content was significantly lower in group L and O than in group C. The content of GSK-3β of group L was higher than in group O??the difference being statistically significant??P??0.05??. Conclusion    Pretreatment with lithium chloride in postoperative aged rats can inhibit the expression of inflammatory cytokines and increase GSK-3β phosphorylation in the hippocampus cells??so p-GSK-3β??ser9??upregulates and inhibites  the apoptosis of brain cells??thereby improved cognitive abilities after the cavity and maxillofacial surgery.  相似文献   
6.
7.
8.
9.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
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