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   1299013篇
  免费   114240篇
  国内免费   4027篇
耳鼻咽喉   18025篇
儿科学   43078篇
妇产科学   34970篇
基础医学   178374篇
口腔科学   37481篇
临床医学   131526篇
内科学   262725篇
皮肤病学   31356篇
神经病学   109514篇
特种医学   48147篇
外国民族医学   388篇
外科学   193623篇
综合类   24824篇
现状与发展   40篇
一般理论   450篇
预防医学   109202篇
眼科学   28836篇
药学   87983篇
  3篇
中国医学   2723篇
肿瘤学   74012篇
  2021年   12474篇
  2020年   10906篇
  2019年   12749篇
  2018年   23440篇
  2017年   19239篇
  2016年   20899篇
  2015年   22768篇
  2014年   29172篇
  2013年   41573篇
  2012年   47240篇
  2011年   49123篇
  2010年   32256篇
  2009年   31507篇
  2008年   45019篇
  2007年   46599篇
  2006年   47048篇
  2005年   44364篇
  2004年   42247篇
  2003年   39970篇
  2002年   38218篇
  2001年   53627篇
  2000年   54134篇
  1999年   46356篇
  1998年   14132篇
  1997年   12692篇
  1996年   12712篇
  1995年   12042篇
  1994年   10701篇
  1993年   9925篇
  1992年   35572篇
  1991年   34396篇
  1990年   33710篇
  1989年   32422篇
  1988年   29594篇
  1987年   29506篇
  1986年   27570篇
  1985年   26485篇
  1984年   19828篇
  1983年   16821篇
  1982年   10129篇
  1979年   17977篇
  1978年   13060篇
  1977年   11120篇
  1976年   10397篇
  1975年   10941篇
  1974年   13254篇
  1973年   12787篇
  1972年   11755篇
  1971年   10956篇
  1970年   10191篇
排序方式: 共有10000条查询结果,搜索用时 252 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.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
4.

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   
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