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   4346篇
  免费   336篇
  国内免费   8篇
耳鼻咽喉   46篇
儿科学   104篇
妇产科学   86篇
基础医学   762篇
口腔科学   58篇
临床医学   541篇
内科学   844篇
皮肤病学   80篇
神经病学   520篇
特种医学   136篇
外科学   404篇
综合类   34篇
一般理论   2篇
预防医学   374篇
眼科学   27篇
药学   257篇
中国医学   25篇
肿瘤学   390篇
  2024年   1篇
  2023年   52篇
  2022年   39篇
  2021年   153篇
  2020年   93篇
  2019年   147篇
  2018年   149篇
  2017年   116篇
  2016年   149篇
  2015年   161篇
  2014年   181篇
  2013年   255篇
  2012年   400篇
  2011年   405篇
  2010年   215篇
  2009年   197篇
  2008年   288篇
  2007年   294篇
  2006年   300篇
  2005年   255篇
  2004年   212篇
  2003年   205篇
  2002年   203篇
  2001年   15篇
  2000年   13篇
  1999年   20篇
  1998年   31篇
  1997年   19篇
  1996年   13篇
  1995年   10篇
  1994年   17篇
  1993年   15篇
  1992年   8篇
  1991年   7篇
  1990年   4篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   6篇
  1985年   2篇
  1984年   6篇
  1983年   7篇
  1982年   7篇
  1981年   1篇
  1976年   2篇
  1974年   5篇
  1970年   1篇
  1894年   1篇
排序方式: 共有4690条查询结果,搜索用时 578 毫秒
91.
92.
BackgroundThe COVID-19 pandemic has resulted in negative impacts on the economy, population health, and health-related quality-of-life (HRQoL).ObjectiveTo assess the impact of COVID-19 on US population HRQoL using the EQ-5D-5L.DesignWe surveyed respondents on physical and mental health, demographics, socioeconomics, brief medical history, current COVID-19 status, sleep, dietary, financial, and spending changes. Results were compared to online and face-to-face US population norms. Predictors of EQ-5D-5L utility were analyzed using both standard and post-lasso OLS regressions. Robustness of regression coefficients against unmeasured confounding was analyzed using the E-Value sensitivity analysis.SubjectsAmazon MTurk workers (n=2776) in the USA.Main MeasuresEQ-5D-5L utility and VAS scores by age group.Key ResultsWe received n=2746 responses. Subjects 18–24 years reported lower mean (SD) health utility (0.752 (0.281)) compared with both online (0.844 (0.184), p=0.001) and face-to-face norms (0.919 (0.127), p<0.001). Among ages 25–34, utility was worse compared to face-to-face norms only (0.825 (0.235) vs. 0.911 (0.111), p<0.001). For ages 35–64, utility was better during pandemic compared to online norms (0.845 (0.195) vs. 0.794 (0.247), p<0.001). At age 65+, utility values (0.827 (0.213)) were similar across all samples. VAS scores were worse for all age groups (p<0.005) except ages 45–54. Increasing age and income were correlated with increased utility, while being Asian, American Indian or Alaska Native, Hispanic, married, living alone, having history of chronic illness or self-reported depression, experiencing COVID-19-like symptoms, having a family member diagnosed with COVID-19, fear of COVID-19, being underweight, and living in California were associated with worse utility scores. Results were robust to unmeasured confounding.ConclusionsHRQoL decreased during the pandemic compared to US population norms, especially for ages 18–24. The mental health impact of COVID-19 is significant and falls primarily on younger adults whose health outcomes may have been overlooked based on policy initiatives to date.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11606-021-06674-z.  相似文献   
93.
94.
Abstract

A theory of the cognitive organisation of lexical processing, verbal short-term memory, and verbal learning is presented along with a summary of data that bear on this issue. We conceive of verbal STM as the outcome of processing that invokes both a specialised short-term memory and the lexical system. On this model, performance of verbal STM tasks depends on the integrity of lexical knowledge, access to that knowledge, and processes that encode serial order information.  相似文献   
95.
96.
Odontoblasts are secretory cells displaying epithelial and mesenchymal features, which exist in a monolayer at the interface between the dentin and pulp of a tooth. During embryogenesis, these cells form a dentin shell and throughout life continue to produce dentin while, also acting as sensor cells helping to mediate tooth sensitivity. In this process, odontoblasts are forced to migrate inwards, resulting in an ongoing loss of pulp volume. Correspondingly, there is also a decrease in the surface area of the dentin which supports the odontoblast cell layer. As these events transpire, odontoblasts maintain a tightly controlled monolayer relationship to each other as well as to their dentin substrate. Stability is maintained laterally by epithelial attachment structures and transversely by complex cytoplasmic extensions into the supporting dentin. As a result, it is not possible for the layer to buckle to relieve the mechanical stresses, which develop during the inward migration. A theoretical consequence of this distinctive self-generated niche is the development of long term compressive stresses within the odontoblast population. We present a mechanobiology model, which causally relates the increase in cellular compressive stresses to contact inhibition of proliferation. We link this hypothesis to the observation that there are no reports of pulpal odontoblasts showing neoplasia or acquisition of changes suggestive of a pre-neoplastic phenotype.  相似文献   
97.
98.
99.
BackgroundThe Composite Asthma Severity Index (CASI) is a comprehensive tool to assess asthma severity, which has been applied in the research setting.ObjectiveTo evaluate, in an outpatient setting, whether a CASI score accurately predicts asthma severity or control as determined by means of subspecialist assessment. Asthma Control Test (ACT) and childhood ACT (C-ACT) scores were generated to provide additional context for CASI scores in relationship to assessments using another clinical tool.MethodsChildren aged 5 to 18 years with a physician diagnosis of persistent asthma were recruited from a tertiary care center. A pediatric pulmonologist made determinations on each participant’s asthma severity and control during a clinic visit. A CASI and ACT/C-ACT score was generated for each patient. Logistic regression and Spearman correlations were used to determine how well CASI scores predicted physician assessments. Agreement between ACT/C-ACT scores and physician assessment of asthma control was determined in supplemental analyses.ResultsCASI scores strongly predicted physician assessment of severity (Spearman correlation = 0.61, P < .001); unadjusted odds ratio (OR) equal to 36.67 (95% confidence interval [CI]: 8.83-152.34); and adjusted OR equal to 32.76 (95% CI: 85.70-188.44). In supplemental analyses, ACT/C-ACT scores strongly predicted physician assessment of control (Spearman correlation = 0.72, P < .001) with an unadjusted OR equal to 42.12 (95% CI: 13.34-133.00) and adjusted OR equal to 55.34 (95% CI: 13.62-224.89).ConclusionUse of the CASI was feasible and accurately predicted physician assessments of asthma severity and control in this sample, which are not distinct entities. The CASI is a robust tool that may be used successfully in ambulatory pediatric asthma care.  相似文献   
100.
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