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   5629篇
  免费   343篇
  国内免费   32篇
耳鼻咽喉   52篇
儿科学   120篇
妇产科学   163篇
基础医学   759篇
口腔科学   102篇
临床医学   450篇
内科学   1227篇
皮肤病学   126篇
神经病学   622篇
特种医学   112篇
外科学   521篇
综合类   13篇
一般理论   1篇
预防医学   435篇
眼科学   65篇
药学   500篇
中国医学   17篇
肿瘤学   719篇
  2024年   11篇
  2023年   46篇
  2022年   120篇
  2021年   182篇
  2020年   123篇
  2019年   142篇
  2018年   159篇
  2017年   138篇
  2016年   148篇
  2015年   184篇
  2014年   223篇
  2013年   267篇
  2012年   474篇
  2011年   394篇
  2010年   228篇
  2009年   200篇
  2008年   357篇
  2007年   353篇
  2006年   382篇
  2005年   372篇
  2004年   341篇
  2003年   309篇
  2002年   268篇
  2001年   45篇
  2000年   36篇
  1999年   39篇
  1998年   53篇
  1997年   34篇
  1996年   41篇
  1995年   39篇
  1994年   27篇
  1993年   31篇
  1992年   17篇
  1991年   22篇
  1990年   9篇
  1989年   12篇
  1988年   23篇
  1987年   13篇
  1986年   14篇
  1985年   12篇
  1984年   14篇
  1983年   10篇
  1982年   8篇
  1981年   6篇
  1979年   12篇
  1978年   10篇
  1975年   5篇
  1974年   7篇
  1969年   6篇
  1966年   12篇
排序方式: 共有6004条查询结果,搜索用时 9 毫秒
81.
Investigation of causal interactions within brain networks using Granger causality analysis (GCA) is a key challenge in studying neural activity on the basis of functional magnetic resonance imaging (fMRI). The article describes an open-source software toolbox GMAC (Granger multivariate autoregressive connectivity) implementing multivariate spectral GCA. Available features are: fMRI data importing/exporting, network nodes definition, time series preprocessing, multivariate autoregressive modeling, spectral Granger causality indexes estimation, statistical significance assessment using surrogate data, network analysis and visualization of connectivity results. All functions have been integrated into a user-friendly graphical interface developed in the Matlab environment, easily accessible to both technical and clinical users.  相似文献   
82.
The aims of the study were to investigate healthy subjects’ performance on a clinical test of high-level language (HLL) and how it is related to demographic characteristics and verbal working memory (VWM). One hundred healthy subjects (20–79 years old) were assessed with the Swedish BeSS test (Laakso, Brunnegård, Hartelius, & Ahlsén, 2000) and two digit span tasks. Relationships between the demographic variables, VWM and BeSS were investigated both with bivariate correlations and multiple regression analysis. The results present the norms for BeSS. The correlations and multiple regression analysis show that demographic variables had limited influence on test performance. Measures of VWM were moderately related to total BeSS score and weakly to moderately correlated with five of the seven subtests. To conclude, education has an influence on the test as a whole but measures of VWM stood out as the most robust predictor of HLL.  相似文献   
83.
84.
85.
Objective: The aim of the analysis is to assess the impact of privately employed migrant care workers (MCWs) on the burden of Italian family members who care for a disabled older person.

Methods: EUROFAMCARE is a one-year prospective survey carried out to provide evidence on the availability and use of support services by family carers of older people in Europe. In Italy, 990 family caregivers were enrolled and successful follow-ups were completed for 863 subjects. The survey also assessed the level of caregiver burden using the COPE index, which has three sub-sections: ‘Positive Value’ (PV), ‘Quality of Support’ (QS) and ‘Negative Impact’ (NI). We used the one-year change of the COPE-NI as dependent variable and we realised multilevel regression models to estimate the longitudinal predictors of caregivers’ burden increase.

Results: At a cross-sectional level, most burdened caregivers are those caring for a demented relative (COPE-NI = 13.6), with no educational title (14.5) and looking after their own spouses (15.1). Longitudinally those employing an MCW are significantly protected against burden increase (regression coefficient: ?1.52; p < 0.01) while those who cannot rely on the support of other family members are exposed to the risk of burden increase (0.991; p < 0.05). Other formal services do not have any protective effect.

Conclusion: Our study suggests that employing an MCW, rather than using formal services, is associated with a reduction of caregiving burden. Further research should assess whether the shift in care responsibilities to the MCWs also implies a transfer of care burden, and understand how these workers can be better supported by existing formal services.  相似文献   
86.
87.
88.
89.
90.
The aim of this study was to evaluate, ex vivo, the histological effects of 445-nm diode laser (Eltech K-Laser srl, Treviso, Italy), during an oral soft ti  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