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   5056篇
  免费   424篇
  国内免费   9篇
耳鼻咽喉   39篇
儿科学   167篇
妇产科学   129篇
基础医学   719篇
口腔科学   36篇
临床医学   671篇
内科学   991篇
皮肤病学   71篇
神经病学   580篇
特种医学   106篇
外科学   432篇
综合类   34篇
一般理论   11篇
预防医学   681篇
眼科学   125篇
药学   311篇
中国医学   8篇
肿瘤学   378篇
  2024年   12篇
  2023年   72篇
  2022年   83篇
  2021年   184篇
  2020年   113篇
  2019年   206篇
  2018年   179篇
  2017年   148篇
  2016年   166篇
  2015年   187篇
  2014年   220篇
  2013年   276篇
  2012年   419篇
  2011年   412篇
  2010年   214篇
  2009年   172篇
  2008年   332篇
  2007年   313篇
  2006年   310篇
  2005年   285篇
  2004年   257篇
  2003年   266篇
  2002年   216篇
  2001年   28篇
  2000年   18篇
  1999年   29篇
  1998年   33篇
  1997年   42篇
  1996年   17篇
  1995年   27篇
  1994年   24篇
  1993年   20篇
  1992年   13篇
  1991年   9篇
  1990年   14篇
  1989年   11篇
  1987年   8篇
  1986年   4篇
  1984年   6篇
  1983年   11篇
  1982年   15篇
  1981年   7篇
  1980年   10篇
  1979年   6篇
  1978年   9篇
  1977年   5篇
  1973年   4篇
  1971年   4篇
  1965年   5篇
  1935年   3篇
排序方式: 共有5489条查询结果,搜索用时 15 毫秒
81.
This study aimed at investigating the reliability and validity of the Arabic Screen for Child Anxiety Related Emotional Disorders (SCARED) as a first child and adolescent anxiety screening tool in the Arab World. The English parent (SCARED-P) and child (SCARED-C) versions were translated into Arabic and administered along with the Arabic Strengths and Difficulties Questionnaire (SDQ) to 77 parents and 67 children attending a Psychiatry clinic. DSM-IV-TR diagnoses were made by a psychiatrist without knowledge of the scale scores. Internal consistency was confirmed by Cronbach's α=0.92 for SCARED-P and 0.91 for SCARED-C. Their subscales had internal consistencies between 0.65 and 0.89. Parent–child agreement was r=0.67, p<0.001. SCARED-P demonstrated good discriminant validity between participants with anxiety disorders and those with other psychiatric disorders (t(72)=3.13, p=0.003). For SCARED-C, this difference was significant when participants with depressive disorders were excluded (t(43)=2.58, p=0.01). Convergent validity was evident through a significant correlation between SCARED-P and the parent SDQ emotional subscale (r=0.70, p<0.001), and SCARED-C and the child SDQ emotional subscale (r=0.70, p<0.001). Divergent validity with the SDQ hyperactivity subscale was observed as no significant correlation was found. Overall, the Arabic SCARED demonstrated satisfactory psychometric properties in a clinical sample in Lebanon.  相似文献   
82.
Cognitive features, which begin before manifestation of the motor features, are an integral part of Huntington’s disease and profoundly affect quality of life. A number of neuropsychological batteries have been used to assess this aspect of the condition, many of which are difficult to administer and time consuming, especially in advanced disease. We, therefore, investigated a simple and practical way to monitor cognition using the Addenbrooke’s Cognitive Examination-Revised (ACE-R) in 126 manifest Huntington’s disease patients, 28 premanifest gene carriers and 21 controls. Using this test, we demonstrated a selective decrease in phonemic, but not semantic, fluency in premanifest participants Cognitive decline in manifest Huntington’s disease varied according to disease severity with extensive cognitive decline observed in early-stage Huntington’s disease patients, indicating that this would be an optimal stage for interventions designed to halt cognitive decline, and lesser changes in the advanced cases. We next examined cognitive performance in patients prescribed antidopaminergic drugs as these drugs are known to decrease cognition when administered to healthy volunteers. We paradoxically found that these drugs may be beneficial, as early-stage Huntington’s disease participants in receipt of them had improved attention and Mini-Mental State Examination scores. In conclusion, this is the first study to test the usefulness of the ACE-R in a Huntington’s disease population and demonstrates that this is a brief, inexpensive and practical way to measure global cognitive performance in clinical practice with potential use in clinical trials.  相似文献   
83.
Abstract

This study aimed to determine the validity and psychometric properties of the Shape- and Weight-Based Self-Esteem (SAWBS) Inventory in British adolescent girls with and without eating disorders. Sixty patients and 60 age-matched controls completed the SAWBS Inventory and measures of eating disorder symptoms, body shape concerns, and depression. Patients also completed the Eating Disorders Examination. Adolescents with eating disorders attributed more of their self-esteem to weight and shape than those without eating disorders. The combination of weight and shape was the most important component of self-esteem for 28% of eating-disordered individuals compared with only 10% of controls. The measure showed acceptable validity in this sample. The SAWBS Inventory appears to be valid in British adolescent girls and is able to differentiate between those with and without eating disorders. The measure is likely to be a useful tool in both clinical and research settings with eating-disordered young people.  相似文献   
84.
Hand D  Burbridge L  Cole BO 《Dental update》2012,39(4):280-284
Complicated crown-root fractures in permanent teeth present both patient-centred and restorative problems when treating the adolescent. This case highlights an alternative and conservative technique for the management of a traumatically involved maxillary left central incisor in a 12-year-old boy. The injury was successfully managed through an interdisciplinary approach using a combination of endodontics, minor oral surgery and orthodontics. The approach resulted in utilizing the patient's own tooth fragment to facilitate restoration back into successful function and aesthetics with the absence of any pathological changes.  相似文献   
85.
86.
Murine MHC class I can be readily expressed on the surface of human cell lines, but human class I molecules are expressed on mouse cells at a reduced level. Both human beta-2-microglobulin (beta(2)m) and tapasin (Tpn) have been demonstrated to be required for proper human MHC class I surface expression. Here we report that besides beta(2)m and tapasin, an extra unidentified component is also critical for the expression of certain human class I alleles. By covalently linking HLA-B4402 heavy chain to beta(2)m (beta(2)m-B44) a pre-assembled class I molecule has been created, which can be efficiently expressed and travel to the surface in human cells. In spite of being able to express inside cells, the linked beta(2)m-B44 molecule does not express on the surface of a murine fibroblast. Further investigation shows that lack of appearance on the surface is not due to quick degradation of unloaded class I, since provision of HLA-B4402 binding peptide could not rescue impaired surface expression. Co-expression with human tapasin does not rescue the defect excluding tapasin as the critical component for expression and indicating that a novel component of human origin is required for efficient surface expression of beta(2)m-B44 in murine cells. Surprisingly, not only did the beta(2)m-B44 construct fail to express on murine cells but also the surface expression of native murine MHC class I Kb was greatly reduced in transfected cells. It is likely that the expressed linked chain competitively associates with a component of class I processing in murine cells, reducing the exit rate of assembled mouse class I molecules. The results together suggest an unknown mechanism, which leads to the trapping of class I molecules in the ER.  相似文献   
87.
88.
QUESTIONS: What is the volume, quality, consistency, and generalisability of the evidence for breathing control? What is the effect on outcomes related to the target and mechanism of breathing control, as well as physiological and clinical outcomes? DESIGN: Systematic review with meta-analysis. PARTICIPANTS: People with chronic respiratory disease, post-surgical, or asymptomatic individuals. INTERVENTION: Breathing control (relaxed basal, diaphragmatic, or abdominal breathing) as the sole intervention. OUTCOME MEASURES: All outcome measures providing continuous data. RESULTS: Twenty studies were included within the meta-analysis. A beneficial effect was found for abdominal movement (SMD 1.36, 95% CI 0.42 to 2.31), diaphragm excursion (SMD 1.39, 95% CI 1.00 to 1.77), respiratory rate (SMD -0.84, 95% CI -1.09 to -0.60), tidal volume (SMD 0.98, 95% CI 0.71 to 1.25), arterial oxygen saturation (SMD 0.63, 95% CI 0.25 to 1.02) and percutaneous oxygen (SMD 1.48, 95% CI 0.85 to 2.11). Breathing control had a detrimental effect on the work of breathing (SMD 1.06, 95% CI 0.52 to 1.60) and dyspnoea (SMD 1.47, 95% CI 0.88 to 2.05). CONCLUSION: When used as a sole intervention, there was a beneficial effect on outcomes related to the mechanism of breathing control as well as on short-term physiological outcomes. In people with severe respiratory disease, breathing control resulted in a detrimental effect on dyspnoea and work of breathing. There was no clear evidence of an effect on ventilation or long-term physiological outcomes related to gas exchange or the energy cost of breathing. Overall, evidence was satisfactory with studies demonstrating poor consistency, good generalisability, and satisfactory volume and quality.  相似文献   
89.
OBJECTIVE: To assess whether respiratory care protocols from different hospitals result in similar care plans for identical patients, we asked: 1. Does applying respiratory care protocols from different hospitals to standardized patient vignettes produce identical care plans? 2. If there are differences in the care plans produced, what is the extent of the difference, and for which modalities are the differences greatest? 3. Does installing the protocol in a computerized information management system to generate the respiratory care plan improve the level of agreement? 4. Do protocols from different hospitals agree with regard to indications for respiratory care treatments and use of the Clinical Practice Guidelines from the American Association for Respiratory Care? METHODS: Protocols were compared by applying each of 4 hospitals' protocols to 15 patient vignettes that we developed, with various respiratory problems. With each vignette, 3 experienced respiratory therapist evaluators developed respiratory care plans, using both a manual (paper-based) and a computer-aided approach. RESULTS: The overall degree of agreement among the 4 protocols was moderate (kappa 0.60, 95% confidence interval 0.46-0.71). The degree of concordance differed for the individual respiratory care modalities; concordance was generally highest for oxygen, aerosol delivery, and pulse oximetry, and was lower for bronchopulmonary hygiene and hyperinflation. Concordance regarding indications for therapy also differed among the modalities; concordance was greatest for the indications for incentive spirometry, bronchodilator use, and pulse oximetry. The concordance of care plans developed with the computer-aided approach resembled that of the manual approach (kappa 0.62, 95% confidence interval 0.45-0.77). CONCLUSIONS: Our results suggest moderate agreement between care plans generated with respiratory care protocols from different hospitals. The sources of differences included differences in the indications for therapy, different degrees of protocol compliance with the American Association for Respiratory Care Clinical Practice Guidelines, and subjectivity in the indications for therapy. This study identifies opportunities to lessen regional variation in respiratory care, by encouraging uniform application of protocols and evidence-based guidelines.  相似文献   
90.
Lasers in Medical Science - The authors aimed to conduct a systematic review to assess data from the current literature on the effectiveness of low-level laser therapy (LLLT) in preventing tooth...  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