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   468513篇
  免费   35309篇
  国内免费   8203篇
耳鼻咽喉   4459篇
儿科学   13093篇
妇产科学   9362篇
基础医学   34523篇
口腔科学   12171篇
临床医学   68735篇
内科学   54504篇
皮肤病学   5502篇
神经病学   25459篇
特种医学   9395篇
外国民族医学   31篇
外科学   43474篇
综合类   62669篇
现状与发展   15篇
一般理论   138篇
预防医学   74213篇
眼科学   5690篇
药学   39044篇
  532篇
中国医学   32374篇
肿瘤学   16642篇
  2023年   9233篇
  2022年   13479篇
  2021年   20483篇
  2020年   19670篇
  2019年   24882篇
  2018年   22124篇
  2017年   18699篇
  2016年   15826篇
  2015年   14956篇
  2014年   29294篇
  2013年   32726篇
  2012年   25980篇
  2011年   28037篇
  2010年   21866篇
  2009年   20695篇
  2008年   19897篇
  2007年   20532篇
  2006年   17827篇
  2005年   15091篇
  2004年   12377篇
  2003年   10600篇
  2002年   8181篇
  2001年   7442篇
  2000年   6223篇
  1999年   5247篇
  1998年   4270篇
  1997年   3933篇
  1996年   3433篇
  1995年   3117篇
  1994年   2955篇
  1993年   2419篇
  1992年   2349篇
  1991年   2029篇
  1990年   1801篇
  1989年   1571篇
  1988年   1516篇
  1987年   1270篇
  1985年   3946篇
  1984年   4906篇
  1983年   3411篇
  1982年   3870篇
  1981年   3608篇
  1980年   3222篇
  1979年   2948篇
  1978年   2561篇
  1977年   1944篇
  1976年   2177篇
  1975年   1661篇
  1974年   1449篇
  1973年   1288篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
Measuring outcomes in health care have become mandatory as regulatory agencies, institutional guidelines, employers, and consumer groups advocate for quality health care focusing on improving patient outcomes. System-level quality departments often provide a framework for performance improvement (PI) that supports the organizational PI plan. However, nurses must learn to lead and be actively involved in projects in the radiology department to ensure key performance indicators are developed with on-the-ground quality management to improve patient outcomes, system performance, and professional development. This article explores such efforts at a large women’s specialty hospital in the Southern United States.  相似文献   
4.
目的 建立蒙药绿松石的质量标准。方法 收集不同产地绿松石,共10批。观察绿松石样品和粉末的性状并进行理化鉴别;按2020年版《中国药典》(四部)通则方法测定绿松石样品中水分、浸出物含量;采用原子吸收光谱法测定绿松石样品铜元素含量。结果 绿松石为不规则、周围带有黑石的块状物,表面蓝绿色,体重,质硬脆,难砸碎,断面呈贝壳状,蜡样光泽,粉末呈灰绿色,无臭,味淡;理化鉴别结果显示,呈铜盐反应;10批次样品中水分含量为0.41%-3.94%(SD=1.37%),浸出物含量为0.21%-0.81%(SD=0.21%),铜元素含量为3.03%-4.63%(SD=0.63%)。结论 初步拟定绿松石中水分含量不得超多5.0%、浸出物含量不得低于0.10%,铜元素含量应为2.60%-4.84%,制定的标准可用于蒙药材绿松石的质量控制。  相似文献   
5.
6.
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   
7.
8.
Whose values matter when considering which environment is healthier for a child whose guardianship is contested? The biological mother from a remote Australian Aboriginal community, who voluntarily relinquished her but has now requested her return? The foster mother who has cared for her in a metropolitan centre in another State of Australia, thousands of kilometres away? The welfare professionals who also live in that city? Or the child herself, who left her birth home and community five years earlier at the age of two? Drawing on a case study of a seven-year old Aboriginal girl, the authors argue that non-Indigenous values trumped Indigenous values without the realisation of key players who were empowered to make such determinations. The article uses Manuel DeLanda's neo-assemblage theory to consider the range of processes that exert themselves to shape place-values and social identity in colonised nations. It will also draw on Erik Erikson's and Lev Vygotsky's theories of psychosocial development to consider competing sets of values that raised feelings of dissonance within the child. Beliefs about what makes a place health-giving are revealed to be complex in colonised nations. Despite policy and legislative changes to better support Aboriginal people and their right to difference, non-Indigenous professionals can continue to be driven by an unrecognised systemic racism. While place-values are not, of course, the only (or perhaps even the most significant) consideration in guardianship determinations, this article will argue they can play a significant and covert role.  相似文献   
9.
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   
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