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   70947篇
  免费   5130篇
  国内免费   353篇
耳鼻咽喉   692篇
儿科学   1996篇
妇产科学   1640篇
基础医学   8709篇
口腔科学   1817篇
临床医学   6993篇
内科学   15978篇
皮肤病学   922篇
神经病学   5604篇
特种医学   2140篇
外国民族医学   2篇
外科学   11126篇
综合类   1182篇
现状与发展   1篇
一般理论   107篇
预防医学   5606篇
眼科学   2227篇
药学   5011篇
中国医学   174篇
肿瘤学   4503篇
  2023年   342篇
  2022年   504篇
  2021年   1451篇
  2020年   869篇
  2019年   1216篇
  2018年   1530篇
  2017年   1056篇
  2016年   1238篇
  2015年   1376篇
  2014年   2136篇
  2013年   3200篇
  2012年   4429篇
  2011年   4708篇
  2010年   2717篇
  2009年   2510篇
  2008年   4485篇
  2007年   4637篇
  2006年   4459篇
  2005年   4470篇
  2004年   4173篇
  2003年   3769篇
  2002年   3693篇
  2001年   849篇
  2000年   733篇
  1999年   829篇
  1998年   804篇
  1997年   652篇
  1996年   527篇
  1995年   516篇
  1994年   496篇
  1993年   469篇
  1992年   574篇
  1991年   552篇
  1990年   459篇
  1989年   475篇
  1988年   436篇
  1987年   397篇
  1986年   379篇
  1985年   456篇
  1984年   462篇
  1983年   419篇
  1982年   550篇
  1981年   459篇
  1980年   499篇
  1979年   319篇
  1978年   338篇
  1977年   340篇
  1976年   273篇
  1975年   298篇
  1974年   262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.
International Ophthalmology - To investigate the efficacy and safety of non-valved Aurolab aqueous drainage implant (AADI) surgery combined with phacoemulsification in eyes with refractory glaucoma...  相似文献   
3.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
4.
ABSTRACT

Informal settlements remain a public health problem as they lack basic infrastructure. Furthermore, it is challenging to enforce public health regulations and protocols to prevent the spread of infection during a pandemic. This paper was set out to explore the impact of lockdown during COVID-19 among people living in informal settlements. An exploratory qualitative design was utilised. Purposive sampling was used to select research participants. In-depth one-to-one interviews were held involving 30 research participants through a WhatsApp online telephone platform. A thematic approach underpinned by the four stages of data analysis in interpretive phenomenological analysis was utilised to analyse the data. The study found that during the the research participants were affected by lack of space to practice social distancing, over-burdened infrastructure, lack of savings, loss of income and shortage of food, hunger and diseases, anxiety and depression and poor access to education. There is a need to prioritise the needs of informal settlers and endeavour to establish permanent homes. Health promotion and communication initiatives and pandemic awareness programmes are needed to mitigate the impact of lockdown during a pandemic in informal settlements.  相似文献   
5.
6.
7.
8.
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