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   98341篇
  免费   30575篇
  国内免费   1415篇
耳鼻咽喉   2434篇
儿科学   2531篇
妇产科学   2290篇
基础医学   2629篇
口腔科学   5101篇
临床医学   26135篇
内科学   24526篇
皮肤病学   3302篇
神经病学   12145篇
特种医学   3626篇
外国民族医学   2篇
外科学   17902篇
综合类   1125篇
现状与发展   41篇
一般理论   1篇
预防医学   13422篇
眼科学   2186篇
药学   1520篇
  4篇
中国医学   446篇
肿瘤学   8963篇
  2024年   557篇
  2023年   5097篇
  2022年   1286篇
  2021年   2978篇
  2020年   5528篇
  2019年   2151篇
  2018年   6983篇
  2017年   7479篇
  2016年   8020篇
  2015年   8174篇
  2014年   10587篇
  2013年   12228篇
  2012年   3805篇
  2011年   3528篇
  2010年   6902篇
  2009年   9149篇
  2008年   3485篇
  2007年   2400篇
  2006年   3555篇
  2005年   2095篇
  2004年   1503篇
  2003年   1230篇
  2002年   1087篇
  2001年   1979篇
  2000年   1217篇
  1999年   1747篇
  1998年   2092篇
  1997年   1944篇
  1996年   1979篇
  1995年   1707篇
  1994年   1107篇
  1993年   923篇
  1992年   753篇
  1991年   638篇
  1990年   524篇
  1989年   524篇
  1988年   506篇
  1987年   383篇
  1986年   356篇
  1985年   293篇
  1984年   250篇
  1983年   298篇
  1982年   221篇
  1981年   196篇
  1980年   117篇
  1978年   119篇
  1977年   114篇
  1976年   83篇
  1974年   70篇
  1972年   72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.
5.
6.
7.
8.
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   
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