首页 | 官方网站   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   242413篇
  免费   43469篇
  国内免费   9447篇
医药卫生   295329篇
  2024年   300篇
  2023年   6797篇
  2022年   4477篇
  2021年   9126篇
  2020年   10371篇
  2019年   6375篇
  2018年   11522篇
  2017年   11775篇
  2016年   11773篇
  2015年   14306篇
  2014年   18504篇
  2013年   20464篇
  2012年   15810篇
  2011年   16529篇
  2010年   15871篇
  2009年   16497篇
  2008年   12543篇
  2007年   11286篇
  2006年   11888篇
  2005年   9588篇
  2004年   6818篇
  2003年   6037篇
  2002年   5012篇
  2001年   5255篇
  2000年   4256篇
  1999年   4487篇
  1998年   3450篇
  1997年   3147篇
  1996年   2949篇
  1995年   2682篇
  1994年   2004篇
  1993年   1431篇
  1992年   1660篇
  1991年   1456篇
  1990年   1185篇
  1989年   1110篇
  1988年   1036篇
  1987年   821篇
  1986年   720篇
  1985年   589篇
  1984年   448篇
  1983年   462篇
  1982年   314篇
  1981年   289篇
  1980年   183篇
  1979年   202篇
  1978年   231篇
  1977年   197篇
  1974年   164篇
  1972年   157篇
排序方式: 共有10000条查询结果,搜索用时 325 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.
目的分析盐酸利托君治疗晚期先兆流产保胎患者的临床疗效及不良反应发生率。方法选取2019年6—12月本院收治的行硫酸镁保胎治疗的35例晚期先兆流产患者作为对照组,另选取2020年1—7月本院收治的行盐酸利托君保胎治疗的35例晚期先兆流产患者作为研究组,比较两组治疗情况、保胎成功率、不良反应发生率、新生儿Apgar评分。结果研究组宫缩消失时间、止血时间、腹痛缓解时间、腰痛缓解时间、起效时间均短于对照组,且延长孕期时间长于对照组(P<0.05);研究组保胎成功33例(94.29%),对照组保胎成功26例(74.29%),差异有统计学意义(P<0.05);研究组不良反应发生率为22.86%,低于对照组的20.00%,但差异无统计学意义;研究组Apgar评分高于对照组,差异有统计学意义(P<0.05)。结论盐酸利托君治疗晚期先兆流产保胎患者,可尽快改善患者临床症状,有助于提高保胎成功率,改善母婴结局,且无明显不良症状,安全性较高,值得临床推广。  相似文献   
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-23

京公网安备 11010802026262号