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   1352576篇
  免费   123743篇
  国内免费   2572篇
耳鼻咽喉   18471篇
儿科学   43281篇
妇产科学   37093篇
基础医学   192140篇
口腔科学   39504篇
临床医学   141980篇
内科学   270148篇
皮肤病学   30450篇
神经病学   113124篇
特种医学   50211篇
外国民族医学   265篇
外科学   195505篇
综合类   25862篇
现状与发展   42篇
一般理论   573篇
预防医学   116843篇
眼科学   30084篇
药学   93825篇
  6篇
中国医学   2038篇
肿瘤学   77446篇
  2021年   11887篇
  2019年   11878篇
  2018年   19881篇
  2017年   17092篇
  2016年   18468篇
  2015年   20360篇
  2014年   27534篇
  2013年   38484篇
  2012年   41274篇
  2011年   43443篇
  2010年   29430篇
  2009年   30624篇
  2008年   41198篇
  2007年   42911篇
  2006年   43407篇
  2005年   41344篇
  2004年   39167篇
  2003年   37245篇
  2002年   36109篇
  2001年   57691篇
  2000年   58091篇
  1999年   49618篇
  1998年   15291篇
  1997年   13948篇
  1996年   14417篇
  1995年   13457篇
  1994年   12066篇
  1992年   38868篇
  1991年   38249篇
  1990年   36893篇
  1989年   35717篇
  1988年   33133篇
  1987年   32375篇
  1986年   30819篇
  1985年   29045篇
  1984年   22172篇
  1983年   19438篇
  1982年   11570篇
  1979年   21003篇
  1978年   15499篇
  1977年   12896篇
  1976年   11924篇
  1975年   12866篇
  1974年   15653篇
  1973年   15412篇
  1972年   14574篇
  1971年   13590篇
  1970年   12839篇
  1969年   12082篇
  1968年   11239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.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
4.
5.
6.
7.
8.
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