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   936篇
  免费   87篇
  国内免费   20篇
耳鼻咽喉   7篇
儿科学   25篇
妇产科学   7篇
基础医学   103篇
口腔科学   50篇
临床医学   82篇
内科学   275篇
皮肤病学   23篇
神经病学   91篇
特种医学   108篇
外科学   101篇
综合类   38篇
预防医学   40篇
眼科学   18篇
药学   42篇
中国医学   3篇
肿瘤学   30篇
  2023年   4篇
  2021年   9篇
  2020年   9篇
  2018年   17篇
  2017年   14篇
  2016年   17篇
  2015年   21篇
  2014年   11篇
  2013年   27篇
  2012年   36篇
  2011年   39篇
  2010年   33篇
  2009年   40篇
  2008年   30篇
  2007年   55篇
  2006年   31篇
  2005年   33篇
  2004年   24篇
  2003年   27篇
  2002年   26篇
  2001年   30篇
  2000年   24篇
  1999年   22篇
  1998年   29篇
  1997年   48篇
  1996年   35篇
  1995年   21篇
  1994年   21篇
  1993年   21篇
  1992年   9篇
  1991年   21篇
  1990年   18篇
  1989年   26篇
  1988年   30篇
  1987年   28篇
  1986年   15篇
  1985年   20篇
  1984年   9篇
  1983年   17篇
  1982年   9篇
  1981年   13篇
  1980年   11篇
  1979年   3篇
  1978年   8篇
  1977年   6篇
  1976年   7篇
  1975年   7篇
  1974年   4篇
  1972年   4篇
  1962年   3篇
排序方式: 共有1043条查询结果,搜索用时 62 毫秒
1.
Journal of Autism and Developmental Disorders - Parents of children with autism spectrum disorder (ASD) experience elevated stress, yet parent-specific interventions are sparse. Thirty-five parents...  相似文献   
2.
3.
4.
SUMMARY Dysbaric symptoms following ascent from a scuba dive are due to symptomatic nitrogen or air emboli with clear patterns of associated injury. This case report highlights an unusual presentation of dysbaric injury treated successfully with a prostacyclin analogue.  相似文献   
5.
6.
Anomalies of the vertebral arteries are uncommon, but important to recognize in the diagnosis and catheter based evaluation and treatment of patients suffering cerebrovascular disease. This article illustrates our experience with such anomalies. These include the vertebral artery arising as the fourth and most distal branch of the aortic arch, as a right subclavian artery branch arising distal to the right thyrocervical trunk, as a right common carotid artery branch in a patient with an aberrant right subclavian artery, and a case of left vertebral artery proximal duplication, with both aortic and left subclavian vertebral arteries present in the same patient; the latter join to form a single distal cervical vertebral artery.  相似文献   
7.
Genetic and environmental control of host-gut microbiota interactions   总被引:1,自引:0,他引:1  
Genetics provides a potentially powerful approach to dissect host-gut microbiota interactions. Toward this end, we profiled gut microbiota using 16s rRNA gene sequencing in a panel of 110 diverse inbred strains of mice. This panel has previously been studied for a wide range of metabolic traits and can be used for high-resolution association mapping. Using a SNP-based approach with a linear mixed model, we estimated the heritability of microbiota composition. We conclude that, in a controlled environment, the genetic background accounts for a substantial fraction of abundance of most common microbiota. The mice were previously studied for response to a high-fat, high-sucrose diet, and we hypothesized that the dietary response was determined in part by gut microbiota composition. We tested this using a cross-fostering strategy in which a strain showing a modest response, SWR, was seeded with microbiota from a strain showing a strong response, A×B19. Consistent with a role of microbiota in dietary response, the cross-fostered SWR pups exhibited a significantly increased response in weight gain. To examine specific microbiota contributing to the response, we identified various genera whose abundance correlated with dietary response. Among these, we chose Akkermansia muciniphila, a common anaerobe previously associated with metabolic effects. When administered to strain A×B19 by gavage, the dietary response was significantly blunted for obesity, plasma lipids, and insulin resistance. In an effort to further understand host-microbiota interactions, we mapped loci controlling microbiota composition and prioritized candidate genes. Our publicly available data provide a resource for future studies.Studies carried out over the last decade have revealed that gut microbiota contribute to a variety of common disorders, including obesity and diabetes (Musso et al. 2011), colitis (Devkota et al. 2012), atherosclerosis (Wang et al. 2011), rheumatoid arthritis (Vaahtovuo et al. 2008), and cancer (Yoshimoto et al. 2013). The evidence for metabolic interactions is particularly strong, as a large body of data now supports the conclusion that gut microbiota influence the energy harvest from dietary components, particularly complex carbohydrates, and that metabolites such as the short-chain fatty acids produced by gut bacteria can perturb metabolic traits, including adiposity and insulin resistance (Turnbaugh et al. 2006, 2009; Backhed et al. 2007; Wen et al. 2008; Ridaura et al. 2013). Gut microbiota communities are assembled each generation, influenced by maternal seeding, environmental factors, host genetics, and age, resulting in substantial variations in composition among individuals in human populations (Eckburg et al. 2005; Costello et al. 2009; Human Microbiome Project Consortium 2012; Goodrich et al. 2014). Most experimental studies of host-gut microbiota interactions have employed large perturbations, such as comparisons of germ-free versus conventional mice, and the significance of common variations in gut microbiota composition for disease susceptibility is still poorly understood. Furthermore, while studies with germ-free mice have clearly implicated microbiota in clinically relevant traits, it has proven difficult to identify the responsible taxa of bacteria.We now report a population-based analysis of host-gut microbiota interactions in the mouse. One of the issues we explore is the role of host genetics. Although some evidence is consistent with significant heritability of gut microbiota composition, the extent to which the host controls microbiota composition under controlled environmental conditions is unclear. We also examined the role of common variations in gut microbiota in metabolic traits such as obesity and insulin resistance and mapped loci contributing to the abundance of certain microbiota. We performed our study using a resource termed the Hybrid Mouse Diversity Panel (HMDP), consisting of about 100 inbred strains of mice that have been either sequenced or subjected to high-density genotyping (Bennett et al. 2010). The resource has several advantages for genetic analysis as compared to traditional genetic crosses. First, it allows high-resolution mapping by association rather than linkage analysis, and it has now been used for the identification of a number of novel genes underlying complex traits (Farber et al. 2011; Lavinsky et al. 2015; Parks et al. 2015; Rau et al. 2015). Second, since the strains are permanent, the data from separate studies can be integrated, allowing the development of large, publicly available databases of physiological and molecular traits relevant to a variety of clinical disorders (systems.genetics.ucla.edu and phenome.jax.org). Third, the panel is ideal for examining gene-by-environment interactions, since it is possible to examine individuals of a particular genotype under a variety of conditions (Orozco et al. 2012; Parks et al. 2013).  相似文献   
8.
9.
10.
BackgroundLeft bundle branch block (LBBB) and left ventricular (LV) dyssynchrony likely contribute to progressive systolic dysfunction. The evaluation of newly recognized LBBB includes screening for structural heart abnormalities and coronary artery disease (CAD). In patients whose LV ejection fraction (EF) is preserved during initial testing, the incidence of subsequent cardiomyopathy is not firmly established.HypothesisThe risk of developing LV systolic dysfunction among LBBB patients with preserved LVEF is high enough to warrant serial imaging.MethodsWe screened records of 1000 consecutive patients with LBBB from our ECG database and identified subjects with an initially preserved LVEF (≥45%) without clinically relevant CAD or other cause for cardiomyopathy. Baseline imaging, clinical data, and follow‐up imaging were recorded to determine the risk of subsequent LV systolic dysfunction (LVEF ≤40%).Results(Data are mean + SD) 784 subjects were excluded, the majority for CAD or depressed LVEF upon initial imaging. Of the remaining 216, 37 (17%) developed a decline in LVEF(≤40%) over a mean follow‐up of 55 ± 31 months; 94% of these patients had a baseline LVEF≤60% and LV end systolic diameter (ESD) ≥ 2.9 cm indicating that these measures may be useful to define which patients warrant longitudinal follow‐up. The negative predictive value of a LVEF>60% and LVESD <2.9 cm was 98%.ConclusionsSeventeen percent of patients with LBBB and initial preserved LVEF develop dyssynchrony cardiomyopathy. We believe the risk of developing dyssynchrony cardiomyopathy is high enough to warrant serial assessment of LV systolic function in this high‐risk population.  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