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   229721篇
  免费   70400篇
  国内免费   1210篇
耳鼻咽喉   3823篇
儿科学   8851篇
妇产科学   4882篇
基础医学   26204篇
口腔科学   10448篇
临床医学   46671篇
内科学   56260篇
皮肤病学   11114篇
神经病学   29146篇
特种医学   6423篇
外国民族医学   33篇
外科学   35530篇
综合类   1105篇
现状与发展   40篇
一般理论   151篇
预防医学   26194篇
眼科学   3937篇
药学   10461篇
  1篇
中国医学   1111篇
肿瘤学   18946篇
  2024年   569篇
  2023年   5327篇
  2022年   1588篇
  2021年   5187篇
  2020年   11043篇
  2019年   13991篇
  2018年   16538篇
  2017年   17715篇
  2016年   18868篇
  2015年   19004篇
  2014年   21970篇
  2013年   25514篇
  2012年   11853篇
  2011年   11989篇
  2010年   16998篇
  2009年   15683篇
  2008年   9652篇
  2007年   8261篇
  2006年   9351篇
  2005年   7528篇
  2004年   6785篇
  2003年   6229篇
  2002年   5998篇
  2001年   3152篇
  2000年   2254篇
  1999年   2513篇
  1998年   3017篇
  1997年   2601篇
  1996年   2568篇
  1995年   2239篇
  1994年   1619篇
  1993年   1441篇
  1992年   1143篇
  1991年   977篇
  1990年   815篇
  1989年   813篇
  1988年   783篇
  1987年   661篇
  1986年   614篇
  1985年   583篇
  1984年   551篇
  1983年   604篇
  1982年   610篇
  1981年   558篇
  1980年   432篇
  1979年   256篇
  1978年   305篇
  1977年   298篇
  1976年   256篇
  1974年   215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.
9.
10.
ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation.  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