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   1051082篇
  免费   81001篇
  国内免费   2914篇
耳鼻咽喉   13522篇
儿科学   35933篇
妇产科学   29887篇
基础医学   152143篇
口腔科学   29042篇
临床医学   95855篇
内科学   205563篇
皮肤病学   23640篇
神经病学   83537篇
特种医学   40109篇
外国民族医学   307篇
外科学   158056篇
综合类   24667篇
现状与发展   1篇
一般理论   486篇
预防医学   82425篇
眼科学   24248篇
药学   75866篇
  3篇
中国医学   2151篇
肿瘤学   57556篇
  2019年   8216篇
  2018年   11669篇
  2017年   9010篇
  2016年   10258篇
  2015年   11633篇
  2014年   16020篇
  2013年   24598篇
  2012年   32432篇
  2011年   34593篇
  2010年   20638篇
  2009年   19466篇
  2008年   32448篇
  2007年   34273篇
  2006年   34668篇
  2005年   33424篇
  2004年   32418篇
  2003年   30967篇
  2002年   29948篇
  2001年   47568篇
  2000年   48601篇
  1999年   40913篇
  1998年   11849篇
  1997年   10660篇
  1996年   10597篇
  1995年   10208篇
  1994年   9516篇
  1993年   8887篇
  1992年   32718篇
  1991年   31914篇
  1990年   31368篇
  1989年   30254篇
  1988年   27502篇
  1987年   27634篇
  1986年   25723篇
  1985年   24957篇
  1984年   18755篇
  1983年   15814篇
  1982年   9724篇
  1981年   8736篇
  1979年   17086篇
  1978年   12478篇
  1977年   10560篇
  1976年   9949篇
  1975年   10407篇
  1974年   12523篇
  1973年   12029篇
  1972年   11042篇
  1971年   10192篇
  1970年   9494篇
  1969年   8800篇
排序方式: 共有10000条查询结果,搜索用时 187 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.
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   
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.
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   
6.
7.
8.
9.
10.
Cognitive Therapy and Research - Despite interest in psychological inflexibility as a marker of suicide risk, no measure of psychological inflexibility specific to SI exists. The present study...  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