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   72989篇
  免费   5465篇
  国内免费   336篇
耳鼻咽喉   689篇
儿科学   1811篇
妇产科学   1676篇
基础医学   9112篇
口腔科学   1706篇
临床医学   7478篇
内科学   15944篇
皮肤病学   945篇
神经病学   6382篇
特种医学   2316篇
外国民族医学   2篇
外科学   10876篇
综合类   1159篇
现状与发展   1篇
一般理论   114篇
预防医学   6408篇
眼科学   2130篇
药学   5185篇
中国医学   159篇
肿瘤学   4697篇
  2023年   334篇
  2022年   527篇
  2021年   1291篇
  2020年   808篇
  2019年   1136篇
  2018年   1398篇
  2017年   970篇
  2016年   1131篇
  2015年   1326篇
  2014年   1990篇
  2013年   3122篇
  2012年   4232篇
  2011年   4599篇
  2010年   2629篇
  2009年   2424篇
  2008年   4456篇
  2007年   4658篇
  2006年   4469篇
  2005年   4573篇
  2004年   4289篇
  2003年   3890篇
  2002年   3851篇
  2001年   973篇
  2000年   966篇
  1999年   1015篇
  1998年   863篇
  1997年   705篇
  1996年   608篇
  1995年   589篇
  1994年   547篇
  1993年   526篇
  1992年   733篇
  1991年   714篇
  1990年   692篇
  1989年   608篇
  1988年   586篇
  1987年   523篇
  1986年   501篇
  1985年   574篇
  1984年   557篇
  1983年   506篇
  1982年   618篇
  1981年   541篇
  1980年   548篇
  1979年   389篇
  1978年   398篇
  1977年   370篇
  1976年   300篇
  1975年   344篇
  1974年   300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.
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.
4.
5.
6.
7.
8.
9.
10.

Background

Patients undergoing cardiac surgery are at significant risk of developing postoperative acute kidney injury (AKI). Neutrophil–lymphocyte ratio (NLR) is a widely available inflammatory biomarker which may be of prognostic value in this setting.

Methods

We conducted a systematic review and meta-analysis of studies reporting associations between perioperative NLR with postoperative AKI. We searched Medline, Embase and the Cochrane Library, without language restriction, from inception to May 2022 for relevant studies. We meta-analysed the reported odds ratios (ORs) with 95% confidence intervals (CIs) for both elevated preoperative and postoperative NLR with risk of postoperative AKI and need for renal replacement therapy (RRT). We conducted a meta-regression to explore inter-study statistical heterogeneity.

Results

Twelve studies involving 10,724 participants undergoing cardiac surgery were included, with eight studies being deemed at high risk of bias using PROBAST modelling. We found statistically significant associations between elevated preoperative NLR and postoperative AKI (OR 1.45, 95% CI 1.18–1.77), as well as postoperative need for RRT (OR 2.37, 95% CI 1.50–3.72). Postoperative NLR measurements were not of prognostic significance.

Conclusions

Elevated preoperative NLR is a reliable inflammatory biomarker for predicting AKI following cardiac surgery.  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