首页 | 官方网站   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   513篇
  免费   18篇
医药卫生   531篇
  2023年   2篇
  2021年   3篇
  2020年   5篇
  2019年   5篇
  2018年   4篇
  2017年   5篇
  2016年   7篇
  2015年   8篇
  2014年   13篇
  2013年   9篇
  2012年   25篇
  2011年   25篇
  2010年   12篇
  2009年   12篇
  2008年   26篇
  2007年   33篇
  2006年   29篇
  2005年   26篇
  2004年   25篇
  2003年   26篇
  2002年   26篇
  2001年   23篇
  2000年   27篇
  1999年   25篇
  1998年   5篇
  1996年   2篇
  1993年   7篇
  1992年   12篇
  1991年   8篇
  1990年   8篇
  1989年   4篇
  1988年   8篇
  1987年   5篇
  1986年   6篇
  1985年   13篇
  1984年   4篇
  1982年   3篇
  1980年   2篇
  1979年   9篇
  1977年   3篇
  1976年   2篇
  1975年   9篇
  1974年   6篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
  1967年   1篇
  1966年   1篇
排序方式: 共有531条查询结果,搜索用时 15 毫秒
1.

Introduction

For never-smokers (smoked <100 lifetime cigarettes), lung cancer (LC) has emerged as an important issue. We aimed to investigate the effects of prevalence changes in tobacco smoking and particulate matter (PM) 2.5 (PM2.5) levels on LC in Taiwan, in relation to contrasting PM2.5 levels, between Northern Taiwan (NT) and Southern Taiwan (ST).

Methods

We reviewed 371,084 patients with LC to assess smoking prevalence and correlations between the incidence of adenocarcinoma lung cancer (AdLC) and non-AdLC. Two subsets were selected to assess different AdLC stage trends and the effect of PM2.5 on survival of patients with AdLC.

Results

From 1995 to 2015, the proportion of male adult ever-smokers decreased from 59.4% to 29.9% whereas the female smoking rate remained low (3.2% to 5.3%). AdLC incidence in males and females increased from 9.06 to 23.25 and 7.05 to 24.22 per 100,000 population, respectively. Since 1993, atmospheric visibility in NT improved (from 7.6 to 11.5 km), but deteriorated in ST (from 16.3 to 4.2 km). The annual percent change in AdLC stages IB to IV was 0.3% since 2009 (95% confidence interval [CI]: -1.9%–2.6%) in NT, and 4.6% since 2007 (95% CI: 3.3%–5.8%) in ST; 53% patients with LC had never smoked. Five-year survival rates for never-smokers, those with EGFR wild-type genes, and female patients with AdLC were 12.6% in NT and 4.5% in ST (hazard ratio: 0.79, 95% CI: 0.70–0.90).

Conclusions

In Taiwan, greater than 50% of patients with LC had never smoked. PM2.5 level changes can affect AdLC incidence and patient survival.  相似文献   
2.
3.
4.
Multisite neuroimaging studies can facilitate the investigation of brain‐related changes in many contexts, including patient groups that are relatively rare in the general population. Though multisite studies have characterized the reliability of brain activation during working memory and motor functional magnetic resonance imaging tasks, emotion processing tasks, pertinent to many clinical populations, remain less explored. A traveling participants study was conducted with eight healthy volunteers scanned twice on consecutive days at each of the eight North American Longitudinal Prodrome Study sites. Tests derived from generalizability theory showed excellent reliability in the amygdala ( = 0.82), inferior frontal gyrus (IFG; = 0.83), anterior cingulate cortex (ACC; = 0.76), insula ( = 0.85), and fusiform gyrus ( = 0.91) for maximum activation and fair to excellent reliability in the amygdala ( = 0.44), IFG ( = 0.48), ACC ( = 0.55), insula ( = 0.42), and fusiform gyrus ( = 0.83) for mean activation across sites and test days. For the amygdala, habituation ( = 0.71) was more stable than mean activation. In a second investigation, data from 111 healthy individuals across sites were aggregated in a voxelwise, quantitative meta‐analysis. When compared with a mixed effects model controlling for site, both approaches identified robust activation in regions consistent with expected results based on prior single‐site research. Overall, regions central to emotion processing showed strong reliability in the traveling participants study and robust activation in the aggregation study. These results support the reliability of blood oxygen level‐dependent signal in emotion processing areas across different sites and scanners and may inform future efforts to increase efficiency and enhance knowledge of rare conditions in the population through multisite neuroimaging paradigms. Hum Brain Mapp 36:2558–2579, 2015. © 2015 Wiley Periodicals, Inc .  相似文献   
5.
Genetic associations involving both rare and common alleles have been reported for schizophrenia but there have been no systematic scans for rare recessive genotypes using fully phased trio data. Here, we use exome sequencing in 604 schizophrenia proband–parent trios to investigate the role of recessive (homozygous or compound heterozygous) nonsynonymous genotypes in the disorder. The burden of recessive genotypes was not significantly increased in probands at either a genome-wide level or in any individual gene after adjustment for multiple testing. At a system level, probands had an excess of nonsynonymous compound heterozygous genotypes (minor allele frequency, MAF ⩽1%) in voltage-gated sodium channels (VGSCs; eight in probands and none in parents, P=1.5 × 104). Previous findings of multiple de novo loss-of-function mutations in this gene family, particularly SCN2A, in autism and intellectual disability provide biological and genetic plausibility for this finding. Pointing further to the involvement of VGSCs in schizophrenia, we found that these genes were enriched for nonsynonymous mutations (MAF ⩽0.1%) in cases genotyped using an exome array, (5585 schizophrenia cases and 8103 controls), and that in the trios data, synaptic proteins interacting with VGSCs were also enriched for both compound heterozygosity (P=0.018) and de novo mutations (P=0.04). However, we were unable to replicate the specific association with compound heterozygosity at VGSCs in an independent sample of Taiwanese schizophrenia trios (N=614). We conclude that recessive genotypes do not appear to make a substantial contribution to schizophrenia at a genome-wide level. Although multiple lines of evidence, including several from this study, suggest that rare mutations in VGSCs contribute to the disorder, in the absence of replication of the original findings regarding compound heterozygosity, this conclusion requires evaluation in a larger sample of trios.  相似文献   
6.
7.
8.
9.

Background  

The use of short screening questionnaires may be a promising option for identifying children at risk for depression in a community setting. The objective of this study was to assess the validity of the Short Mood and Feelings Questionnaire (SMFQ) and one- and two-item screening instruments for depressive disorders in a school-based sample of young adolescents.  相似文献   
10.
We evaluated the discrepancy of endophenotypic performance between probands with schizophrenia and unaffected siblings by paternal age at proband birth, a possible marker for de novo mutations. Pairs of schizophrenia probands and unaffected siblings (N=220 pairs) were evaluated on 11 neuropsychological or neurophysiological endophenotypes previously identified as heritable. For each endophenotype, the sibling-minus-proband differences were transformed to standardized scores. Then for each pair, the average discrepancy was calculated from its standardized scores. We tested the hypothesis that the discrepancy is associated with paternal age, controlling for the number of endophenotypes shared between proband and his or her sibling, and proband age, which were both associated with paternal age. The non-significant association between the discrepancy and paternal age was in the opposite direction from the hypothesis. Of the 11 endophenotypes only sensori-motor dexterity was significant, but in the opposite direction. Eight other endophenotypes were also in the opposite direction, but not significant. The results did not support the hypothesized association of increased differences between sibling/proband pairs with greater paternal age. A possible explanation is that the identification of heritable endophenotypes was based on samples for which schizophrenia was attributable to inherited rather than de novo/non-inherited causes.  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-23

京公网安备 11010802026262号