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   282765篇
  免费   75805篇
  国内免费   7626篇
耳鼻咽喉   4395篇
儿科学   8125篇
妇产科学   5506篇
基础医学   30230篇
口腔科学   12046篇
临床医学   49840篇
内科学   62690篇
皮肤病学   11534篇
神经病学   28412篇
特种医学   9274篇
外国民族医学   40篇
外科学   42077篇
综合类   19576篇
现状与发展   60篇
一般理论   39篇
预防医学   25045篇
眼科学   6536篇
药学   19301篇
  114篇
中国医学   7526篇
肿瘤学   23830篇
  2024年   817篇
  2023年   6452篇
  2022年   4618篇
  2021年   9237篇
  2020年   14000篇
  2019年   15798篇
  2018年   18460篇
  2017年   19973篇
  2016年   20525篇
  2015年   22423篇
  2014年   26321篇
  2013年   28763篇
  2012年   16843篇
  2011年   17362篇
  2010年   21451篇
  2009年   19178篇
  2008年   12570篇
  2007年   10579篇
  2006年   11392篇
  2005年   9112篇
  2004年   6699篇
  2003年   5982篇
  2002年   5246篇
  2001年   5651篇
  2000年   4662篇
  1999年   4544篇
  1998年   3367篇
  1997年   3100篇
  1996年   2932篇
  1995年   2629篇
  1994年   1977篇
  1993年   1424篇
  1992年   1652篇
  1991年   1447篇
  1990年   1190篇
  1989年   1097篇
  1988年   1032篇
  1987年   832篇
  1986年   717篇
  1985年   591篇
  1984年   446篇
  1983年   476篇
  1982年   322篇
  1981年   298篇
  1980年   190篇
  1979年   210篇
  1978年   239篇
  1977年   204篇
  1974年   177篇
  1972年   164篇
排序方式: 共有10000条查询结果,搜索用时 46 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.
5.
6.
7.
8.
9.
10.
Zedoary tumeric (Curcumae Rhizoma, Ezhu in Chinese) has a long history of application and has great potential in the treatment of liver cancer. The anti liver cancer effect of zedoary tumeric depends on the combined action of multiple pharmacodynamic substances. In order to clarify the specific mechanism of zedoary tumeric against liver cancer, this paper first analyzes the mechanism of its single pharmacodynamic substance against liver cancer, and then verifies the joint anti liver cancer mechanism of its "pharmacodynamic group". By searching the research on the anti hepatoma effect of active components of zedoary tumeric in recent years, we found that pharmacodynamic substances, including curcumol, zedoarondiol, curcumenol, curzerenone, curdione, curcumin, germacrone, β-elemene, can act on multi-target and multi-channel to play an anti hepatoma role. For example, curcumin can regulate miR, GLO1, CD133, VEGF, YAP, LIN28B, GPR81, HCAR-1, P53 and PI3K/Akt/mTOR, HSP70/TLR4 and NF-κB. Wnt/TGF/EMT, Nrf2/Keap1, JAK/STAT and other pathways play an anti hepatoma role. Network pharmacological analysis showed that the core targets of the "pharmacodynamic group" for anti-life cancer are AKT1, EGFR, MAPK8, etc, and the core pathways are neuroactive live receiver interaction, nitrogen metabolism, HIF-1 signaling pathway, etc. At the same time, by comparing and analyzing the relationship between the specific mechanisms of pharmacodynamic substance and "pharmacodynamic group", it is found that they have great reference significance in target, pathway, biological function, determination of core pharmacodynamic components, formation of core target protein interaction, in-depth research of single pharmacodynamic substance, increasing curative effect and so on. By analyzing the internal mechanism of zedoary tumeric pharmacodynamic substance and "pharmacodynamic group" in the treatment of liver cancer, this paper intends to provide some ideas and references for the deeper pharmacological research of zedoary tumeric and the relationship between pharmacodynamic substance and "pharmacodynamic group".  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