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   104734篇
  免费   10373篇
  国内免费   668篇
耳鼻咽喉   291篇
儿科学   2166篇
妇产科学   1791篇
基础医学   5952篇
口腔科学   4546篇
临床医学   18966篇
内科学   8498篇
皮肤病学   689篇
神经病学   5633篇
特种医学   955篇
外科学   3970篇
综合类   11682篇
现状与发展   5篇
一般理论   95篇
预防医学   41860篇
眼科学   392篇
药学   4880篇
  112篇
中国医学   1151篇
肿瘤学   2141篇
  2024年   384篇
  2023年   3016篇
  2022年   4022篇
  2021年   5598篇
  2020年   5874篇
  2019年   5450篇
  2018年   4717篇
  2017年   4519篇
  2016年   4350篇
  2015年   4326篇
  2014年   7198篇
  2013年   9224篇
  2012年   6386篇
  2011年   6877篇
  2010年   5155篇
  2009年   5053篇
  2008年   4956篇
  2007年   4911篇
  2006年   4199篇
  2005年   3268篇
  2004年   2758篇
  2003年   2390篇
  2002年   1777篇
  2001年   1681篇
  2000年   1435篇
  1999年   995篇
  1998年   843篇
  1997年   667篇
  1996年   571篇
  1995年   372篇
  1994年   360篇
  1993年   351篇
  1992年   276篇
  1991年   239篇
  1990年   205篇
  1989年   161篇
  1988年   189篇
  1987年   126篇
  1986年   109篇
  1985年   150篇
  1984年   100篇
  1983年   68篇
  1982年   61篇
  1981年   64篇
  1980年   63篇
  1979年   46篇
  1978年   43篇
  1977年   60篇
  1976年   48篇
  1975年   42篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.

Objective

The aim of the study was to estimate the effect of the state-based reinsurance programs through the section 1332 State Innovation Waivers on health insurance marketplace premiums and insurer participation.

Data Source

2015 to 2022 Robert Wood Johnson Foundation Health Insurance Exchange Compare Datasets.

Study Design

An event study difference-in-differences (DD) model separately for each year of implementation and a synthetic control method (SCM) are used to estimate year-by-year effects following program implementation.

Data Collection/Extraction Methods

Not applicable.

Principal Findings

Reinsurance programs were associated with a decline in premiums in the first year of implementation by 10%–13%, 5%–19%, and 11%–17% for bronze, silver, and gold plans (p < 0.05). There is a trend of sustained declines especially for states that implemented their programs in 2019 and 2020. The SCM analyses suggest some effect heterogeneity across states but also premium declines across most states. There is no evidence that reinsurance programs affected insurer participation.

Conclusion

State-based reinsurance programs have the potential to improve the affordability of health insurance coverage. However, reinsurance programs do not appear to have had an effect on insurer participation, highlighting the need for policy makers to consider complementary strategies to encourage insurer participation.  相似文献   
2.
3.
4.
PurposeAccording to the social determinants of health framework, income inequality is a potential risk factor for adverse mental health. However, few studies have explored the mechanisms suspected to mediate this relationship. The current study addresses this gap through a mediation analysis to determine if social support and community engagement act as mediators linking neighbourhood income inequality to maternal anxiety and depressive symptoms within a cohort of new mothers living in the City of Calgary, Canada.MethodsData collected at three years postpartum from mothers belonging to the All Our Families (AOF) cohort were used in the current study. Maternal data were collected between 2012 and 2015 and linked to neighbourhood socioeconomic data from the 2006 Canadian Census. Income inequality was measured using Gini coefficients derived from 2006 after-tax census data. Generalized structural equation models were used to quantify the associations between income inequality and mental health symptoms, and to assess the potential direct and indirect mediating effects of maternal social support and community engagement.ResultsIncome inequality was not significantly associated with higher depressive symptoms (β = 0.32, 95%CI = −0.067, 0.70), anxiety symptoms (β = 0.11, 95%CI = −0.39, 0.60), or lower social support. Income inequality was not associated with community engagement. For the depression models, higher social support was significantly associated with lower depressive symptoms (β = −0.13, 95%CI = −0.15, −0.097), while community engagement was not significantly associated with depressive symptoms (β = 0.059, 95%CI = −0.15, 0.27). Similarly, for the anxiety models, lower anxiety symptoms were significantly associated with higher levels of social support (β = −0.17, 95%CI = −0.20, −0.13) but not with higher levels of community engagement (β = 0.14, 95%CI = −0.14, 0.41).ConclusionThe current study did not find clear evidence for social support or community engagement mediating the relationship between neighbourhood income inequality and maternal mental health. Future investigations should employ a broader longitudinal approach to capture changes in income inequality, potential mediators, and mental health symptomatology over time.  相似文献   
5.
6.
The effects of climate change include floods, hurricanes, heat waves, and fires; these natural disasters can result in respiratory, cardiovascular, and psychological harm in older adults, who experience the highest morbidity and mortality during heat waves. Advanced practice registered nurses (APRNs) need education on preparing, assessing, and treating older adults for climate-change disasters, especially heat waves. This article will help APRNs understand the effects of climate-change events on the vulnerable older adults and advocates for the need to integrate health effects of climate change into curricula, practicums, policy, and research agendas.  相似文献   
7.
8.
Child benefits are typically paid from birth. This paper asks whether starting universal child benefits in pregnancy leads to improvements in infant health. Leveraging administrative birth registry and hospital microdata from England and Wales, I study the effects of the Health in Pregnancy Grant, a universal conditional cash transfer equivalent to three months of child benefit (190 GBP) as a lump sum to pregnant mothers from 2009 to 2011. I exploit quasi-experimental variation in eligibility with a regression discontinuity design in the date of birth of the baby. I find that the policy increased birth weight by 8–12 grams on average, reduced low birth weight (<2500 g) by 3-6 percent and decreased prematurity by 9–11 percent. Younger mothers, particularly those living in deprived areas, benefit the most. I present evidence that the mechanisms are unlikely to be antenatal care, nutrition or smoking, with reductions in stress remaining a possible explanation.  相似文献   
9.
10.
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