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   1124篇
  免费   92篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   48篇
妇产科学   17篇
基础医学   142篇
口腔科学   12篇
临床医学   202篇
内科学   289篇
皮肤病学   5篇
神经病学   73篇
特种医学   28篇
外科学   119篇
综合类   5篇
一般理论   2篇
预防医学   154篇
眼科学   16篇
药学   65篇
肿瘤学   38篇
  2023年   12篇
  2022年   15篇
  2021年   46篇
  2020年   18篇
  2019年   39篇
  2018年   31篇
  2017年   26篇
  2016年   41篇
  2015年   25篇
  2014年   32篇
  2013年   50篇
  2012年   113篇
  2011年   96篇
  2010年   38篇
  2009年   39篇
  2008年   57篇
  2007年   51篇
  2006年   47篇
  2005年   42篇
  2004年   49篇
  2003年   47篇
  2002年   40篇
  2001年   22篇
  2000年   42篇
  1999年   26篇
  1998年   20篇
  1997年   10篇
  1996年   4篇
  1995年   8篇
  1994年   5篇
  1992年   19篇
  1991年   15篇
  1990年   14篇
  1989年   10篇
  1988年   7篇
  1987年   8篇
  1986年   7篇
  1985年   9篇
  1984年   5篇
  1983年   5篇
  1982年   2篇
  1981年   5篇
  1980年   4篇
  1979年   2篇
  1978年   3篇
  1977年   3篇
  1974年   2篇
  1973年   3篇
  1971年   1篇
  1960年   1篇
排序方式: 共有1218条查询结果,搜索用时 15 毫秒
101.
Posttraumatic nightmares are considered as a reexperiencing symptom of the DSM‐IV posttraumatic stress disorder (PTSD) diagnosis. Different types of posttraumatic nightmares, however, may differ in their relation to psychopathology. Thirty‐two children were longitudinally assessed 10 days, 2 months, and 6 months after traffic accidents. Occurrence and characteristics of nightmares were examined and their relation to psychopathology assessed. Thirty‐four percent of children reported posttraumatic nightmares during at least one assessment. Exact replicative nightmares at baseline assessment predicted PTSD symptoms 2 and 6 months postaccident, but not depressive symptoms. Exact replicative nightmares revealed the strongest cross‐sectional association with trauma‐specific psychopathology but not with depression. The authors conclude that posttraumatic nightmares—especially exact replicative ones—may be closely related to psychopathological mechanisms of posttraumatic stress in children.  相似文献   
102.
103.
104.
Mutations in the RECQL4 gene can lead to three clinical phenotypes with overlapping features. All these syndromes, Rothmund-Thomson (RTS), RAPADILINO and Baller-Gerold (BGS), are characterized by growth retardation and radial defects, but RAPADILINO syndrome lacks the main dermal manifestation, poikiloderma that is a hallmark feature in both RTS and BGS. It has been previously shown that RTS patients with RECQL4 mutations are at increased risk of osteosarcoma, but the precise incidence of cancer in RAPADILINO and BGS has not been determined. Here, we report that RAPADILINO patients identified as carriers of the c.1390+2delT mutation (p.Ala420_Ala463del) are at increased risk to develop lymphoma or osteosarcoma (6 out of 15 patients). We also summarize all the published RECQL4 mutations and their associated cancer cases and provide an update of 14 novel RECQL4 mutations with accompanying clinical data.  相似文献   
105.
106.

Background and aim

Trunk performance is an important predictor of functional outcome after stroke. However, the percentage of explained variance varies considerably between studies. This may be explained by the stroke population examined, the different scales used to assess trunk performance and the time points used to measure outcome. The aim of this multicentre study was to examine the predictive validity of the Trunk Impairment Scale (TIS) and its subscales when predicting the Barthel Index score at 6 months after stroke.

Methods

A total of 102 subjects were recruited in three European rehabilitation centres. Participants were assessed on admission (median time since stroke onset 20 days) and 6 months after stroke. Correlation analysis and forward stepwise multiple regression analysis were used to model outcome.

Results

The best predictors of the Barthel Index scores at 6 months after stroke were total TIS score (partial R2 = 0.52, p<.0001) and static sitting balance subscale score (partial R2 = 0.50, p<.0001) on admission. The TIS score on admission and its static sitting balance subscale were stronger predictors of the Barthel Index score at 6 months than the Barthel Index score itself on admission.

Conclusions

This study emphasises the importance of trunk performance, especially static sitting balance, when predicting functional outcome after stroke. The TIS is recommended as a prediction instrument in the rehabilitation setting when considering the prognosis of stroke patients. Future studies should address the evolution of trunk performance over time and the evaluation of treatment interventions to improve trunk performance.Although the age specific incidence of major stroke has fallen over the past few years,1 it is still the main cause of long term disability in adults, with a growing number of survivors being dependent for activities of daily living (ADL).2,3 Frequently identified variables predicting ADL after stroke are age and initial severity of motor and functional deficits.4 Trunk performance has also been identified as an important independent predictor of ADL after stroke.5,6,7,8,9 However, based on multiple regression analyses, the reported variance of functional outcome after stroke explained by trunk performance ranges from 9% to 71%.5,6,7,8,9 Differences in reported variance could be explained by the stroke population included, the various scales used to measure trunk performance and the time points used to measure outcome.Previous studies evaluating the predictive validity of trunk performance after stroke were performed in a single rehabilitation setting, warranting caution when generalising results.5,6,7,8,9,10 Clinical tools used to assess trunk performance are the Trunk Control Test,5,6,10 trunk control items of the Postural Assessment Scale for Stroke patients7,8 and trunk assessment of Fujiwara et al.9 A limitation of the first two tests is that they both have a ceiling effect, which makes their use less suitable in long term outcome studies.5,11,12,13 Furthermore, the trunk control items of the Trunk Control Test and Postural Assessment Scale for Stroke patients are largely comparable with the items of the trunk measure of Fujiwara et al.9 All previously mentioned clinical tools include items in the supine position which involve rolling as well as only basic balance movements in sitting. Finally, with the exception of the trunk control items of the Postural Assessment Scale for Stroke patients,8 no study has evaluated the prognostic value of trunk performance when predicting functional outcome at 6 months after stroke.The Trunk Impairment Scale (TIS) for patients after stroke was designed to measure ADL related selective trunk movements rather than participation of the trunk in gross transfer movements.14 The TIS assesses static and dynamic sitting balance and trunk coordination. Reliability, validity, measurement error, internal consistency and discriminant ability of the TIS have been reported elsewhere.14,15 The TIS has no ceiling effect in subacute and chronic stroke patients and already appeared to be strongly related to measures of gait, balance and functional ability in a cross sectional study.12 To the best of our knowledge, the predictive value of the TIS and its subscales has not been evaluated. Including age and other measures of motor and functional performance could provide a useful combination of variables predicting outcome after stroke. The Barthel Index score is a widely accepted measure in stroke rehabilitation research and assesses functional milestones in stroke recovery. Predicting Barthel Index scores at 6 months after stroke based on measurements taken on admission to a rehabilitation centre would further establish the importance of trunk performance when predicting long term outcome after stroke. Experts in the field of neurological rehabilitation have addressed the trunk as the central key point of the body.16 Proximal stability of the trunk is a prerequisite for distal head and limb movement and therefore expected to be related to functional ADL.In summary, there is still a lack of clarity regarding the importance of trunk performance in functional outcome after stroke. Scales which have been used in previous studies have important statistical limitations and are likely to be a comprehensive measure of motor performance of the trunk. Therefore, the aim of this multicentre study was to examine the predictive validity of the TIS and its subcomponents, together with other known predictors, in predicting functional outcome measured as a Barthel Index score at 6 months after stroke.  相似文献   
107.
108.
The application of advances in biomedical computing to medical imaging research is enabling scientists to conduct quantitative clinical imaging studies using data collected across multiple sites to test new hypotheses on larger cohorts, increasing the power to detect subtle effects. Given that many research groups have valuable existing (legacy) data, one goal of the Morphometry Biomedical Informatics Research Network (BIRN) Testbed is to assess the feasibility of pooled analyses of legacy structural neuroimaging data in normal aging and Alzheimer’s disease. The present study examined whether such data could be meaningfully reanalyzed as a larger combined data set by using rigorous data curation, image analysis, and statistical modeling methods; in this case, to test the hypothesis that hippocampal volume decreases with age and to investigate findings of hippocampal asymmetry. This report describes our work with legacy T1-weighted magnetic resonance (MR) and demographic data related to normal aging that have been shared through the BIRN by three research sites. Results suggest that, in the present application, legacy MR data from multiple sites can be pooled to investigate questions of scientific interest. In particular, statistical analyses suggested that a mixed-effects model employing site as a random effect best fits the data, accounting for site-specific effects while taking advantage of expected comparability of age-related effects. In the combined sample from three sites, significant age-related decline of hippocampal volume and right-dominant hippocampal asymmetry were detected in healthy elderly controls. These expected findings support the feasibility of combining legacy data to investigate novel scientific questions. Brad Dickerson and Randy L. Gollub contributed equally.  相似文献   
109.
The type I interferons, interferon-beta and alpha (IFN-β, IFN-α), are widely used for the treatment of autoimmune demyelination in the central nervous system (CNS). Their effects on de- and remyelination through the broadly expressed type I IFN receptor (IFNAR), however, are highly speculative. In order to elucidate the role of endogenous type I interferons for myelin damage and recovery we induced toxic demyelination in the absence of IFNAR1. We demonstrate that IFNAR signalling was induced during acute demyelination since the cytokine IFN-β as well as the IFN-dependent genes IRF7, ISG15 and UBP43 were strongly upregulated. Myelin damage, astrocytic and microglia response, however, were not significantly reduced in the absence of IFNAR1. Furthermore, motor skills of IFNAR1-deficient animals during non-immune demyelination were unaltered. Finally, myelin recovery was found to be independent from endogenous IFNAR signalling, indicating a redundant role of this receptor for non-inflammatory myelin damage and repair.  相似文献   
110.

AIMS

This study aimed to investigate possible effects of ABCB1 genotype on fluvastatin, pravastatin, lovastatin, and rosuvastatin pharmacokinetics.

METHODS

In a fixed-order crossover study, 10 healthy volunteers with the ABCB1 c.1236C/C-c.2677G/G-c.3435C/C (CGC/CGC) genotype and 10 with the c.1236T/T-c.2677T/T-c.3435T/T (TTT/TTT) genotype ingested a single 20-mg dose of fluvastatin, pravastatin, lovastatin, and rosuvastatin. Plasma fluvastatin, pravastatin, and lovastatin concentrations were measured up to 12 h and plasma and urine rosuvastatin concentrations up to 48 and 24 h, respectively.

RESULTS

The ABCB1 genotype had no significant effect on the pharmacokinetics of any of the investigated statins. The geometric mean ratio (95% confidence interval) of the area under the plasma concentration–time curve from 0 h to infinity (AUC0–∞) in participants with the TTT/TTT genotype to that in those with the CGC/CGC genotype was 0.96 (0.77, 1.20; P= 0.737) for fluvastatin, 0.92 (0.53, 1.62; P= 0.772) for pravastatin, 0.83 (0.36, 1.90; P= 0.644) for lovastatin, 1.25 (0.72, 2.17; P= 0.400) for lovastatin acid, and 1.10 (0.73, 1.65; P= 0.626) for rosuvastatin. The AUC0–∞ of lovastatin acid correlated significantly with that of rosuvastatin (r= 0.570, P= 0.009), but none of the other AUC0–∞ pairs showed a significant correlation.

CONCLUSIONS

These data suggest that the ABCB1 c.1236C-c.2677G-c.3435C and c.1236T-c.2677T-c.3435T haplotypes play no significant role in the interindividual variability in the pharmacokinetics of fluvastatin, pravastatin, lovastatin, and rosuvastatin.  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