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   914篇
  免费   53篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   16篇
妇产科学   37篇
基础医学   144篇
口腔科学   25篇
临床医学   112篇
内科学   153篇
神经病学   95篇
特种医学   74篇
外科学   85篇
综合类   3篇
一般理论   1篇
预防医学   78篇
眼科学   14篇
药学   50篇
中国医学   1篇
肿瘤学   73篇
  2024年   2篇
  2023年   8篇
  2022年   23篇
  2021年   36篇
  2020年   29篇
  2019年   36篇
  2018年   34篇
  2017年   34篇
  2016年   33篇
  2015年   35篇
  2014年   42篇
  2013年   54篇
  2012年   88篇
  2011年   75篇
  2010年   51篇
  2009年   45篇
  2008年   55篇
  2007年   45篇
  2006年   48篇
  2005年   34篇
  2004年   32篇
  2003年   25篇
  2002年   19篇
  2001年   8篇
  2000年   2篇
  1999年   4篇
  1998年   2篇
  1997年   5篇
  1996年   9篇
  1994年   3篇
  1992年   4篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1984年   3篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   4篇
  1976年   2篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1971年   5篇
  1970年   1篇
  1969年   4篇
  1947年   1篇
  1922年   1篇
排序方式: 共有968条查询结果,搜索用时 12 毫秒
21.
22.
Trocar injuries are a possible cause for severe morbidity and mortality when performing laparoscopic surgery. This systematic review investigates the differences in the incidence of complications depending on the method of entry. A meta-analysis of the medical literature was performed. Search results were limited to clinical trials and the following languages: English, French, German, or Dutch. All results that compared the Veress, Hasson, and direct entry technique or compared sharp, blunt, and radially expanding trocars (RET) were included (n = 19). Studies involving pediatric and pregnant patients were excluded. When comparing the Veress needle to direct trocar insertion (DTI), pooled analysis showed a borderline significant reduction for major complications (p = 0.04) based on five events in 2 RCT’s (n = 978) and a reduction in minor complications (p < 0.001) in favor of DTI. RCT’s comparing the Hasson and Veress techniques showed no significant reduction in major complications (p = 0.17), but the Hasson technique showed significantly less minor complications (p = 0.01) and failed entries (p = 0.002). CO2 leakage was far more common when using the Hasson technique (p < 0.001). Our search method did not reveal any studies comparing the Hasson technique to DTI. When comparing bladed to RET, three studies (n = 408) showed less minor complications when using a RET (p = 0.003) and a qualitative analysis showed a trend toward pain reduction when using RET. This meta-analysis concludes that there are less minor complications and failed attempts when using the Hasson or direct entry technique when compared to the Veress method, but there is limited evidence regarding major complications. RET reduce minor vascular complications when compared to bladed trocars.  相似文献   
23.
Minor motor and sensory deficits or neurological soft signs (NSS) are frequently found in patients with schizophrenia at any stage of their illness. Although previous studies have reported that NSS are associated with altered structure and function within fronto-parietal areas, it remains unclear whether the neuroanatomical basis of NSS may be confounded by underlying pathological processes, and by antipsychotic treatment. Morphological brain correlates of NSS in healthy subjects have seldom been investigated. This study evaluated the relationship between NSS levels and abnormalities of subcortical and cortical structures in healthy individuals. High-resolution MRI data at 3 Tesla were obtained from 68 healthy individuals. Automated segmentation of caudate nucleus, putamen, globus pallidus, thalamus, and brainstem was performed using both FSL-FIRST and Freesurfer. The surface-based analysis via Freesurfer enabled calculation of cortical thickness, area and folding (local gyrification index). NSS were examined on the Heidelberg Scale and related to both subcortical and cortical measurements. Using two fully automated brain segmentations methods, we found no significant association between NSS levels and morphological changes in subcortical structures. Higher NSS scores were associated with morphological changes of cortical thickness, area and folding in multiple areas comprising superior frontal, middle temporal, insular and postcentral regions. Our findings demonstrate the benefit of surface-based approaches when investigating brain correlates of NSS. The data lend further support to the hypothesis that NSS in healthy individuals involve multiple cortical rather than subcortical brain regions.  相似文献   
24.
BackgroundPrior studies of rapid response team (RRT) implementation for surgical patients have demonstrated mixed results with respect to reductions in poor outcomes. The aim of this study was to identify predictors of in-hospital mortality and hospital costs among surgical inpatients requiring RRT activation.MethodsWe analyzed data prospectively collected from May 2012 to May 2016 at The Ottawa Hospital. We included patients who were at least 18 years of age, who were admitted to hospital, who received either preoperative or postoperative care, and and who required RRT activation. We created a multivariable logistic regression model to describe mortality predictors and a multivariable generalized linear model to describe cost predictors.ResultsWe included 1507 patients. The in-hospital mortality rate was 15.9%. The patient-related factors most strongly associated with mortality included an Elixhauser Comorbidity Index score of 20 or higher (odds ratio [OR] 3.60, 95% confidence interval [CI] 1.96–6.60) and care designations excluding admission to the intensive care unit and cardiopulmonary resuscitation (OR 3.52, 95% CI 2.25–5.52). The strongest surgical predictors included neurosurgical admission (OR 2.09, 95% CI 1.17–3.75), emergent surgery (OR 2.04, 95% CI 1.37–3.03) and occurrence of 2 or more operations (OR 1.73, 95% CI 1.21–2.46). Among RRT factors, occurrence of 2 or more RRT assessments (OR 2.01, 95% CI 1.44–2.80) conferred the highest mortality. Increased cost was strongly associated with admitting service, multiple surgeries, multiple RRT assessments and medical comorbidity.ConclusionRRT activation among surgical inpatients identifies a population at high risk of death. We identified several predictors of mortality and cost, which represent opportunities for future quality improvement and patient safety initiatives.  相似文献   
25.
26.
27.
28.
The ventricular walls of the human heart comprise an outer compact layer and an inner trabecular layer. In the context of an increased pre‐test probability, diagnosis left ventricular noncompaction cardiomyopathy is given when the left ventricle is excessively trabeculated in volume (trabecular vol >25% of total LV wall volume) or thickness (trabecular/compact (T/C) >2.3). Here, we investigated whether higher spatial resolution affects the detection of trabeculation and thus the assessment of normal and excessively trabeculated wall morphology. First, we screened left ventricles in 1112 post‐natal autopsy hearts. We identified five excessively trabeculated hearts and this low prevalence of excessive trabeculation is in agreement with pathology reports but contrasts the prevalence of approximately 10% of the population found by in vivo non‐invasive imaging. Using macroscopy, histology and low‐ and high‐resolution MRI, the five excessively trabeculated hearts were compared with six normal hearts and seven abnormally trabeculated and excessive trabeculation‐negative hearts. Some abnormally trabeculated hearts could be considered excessively trabeculated macroscopically because of a trabecular outflow or an excessive number of trabeculations, but they were excessive trabeculation‐negative when assessed with MRI‐based measurements (T/C <2.3 and vol <25%). The number of detected trabeculations and T/C ratio were positively correlated with higher spatial resolution. Using measurements on high resolution MRI and with histological validation, we could not replicate the correlation between trabeculations of the left and right ventricle that has been previously reported. In conclusion, higher spatial resolution may affect the sensitivity of diagnostic measurements and in addition could allow for novel measurements such as counting of trabeculations.  相似文献   
29.
30.
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