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   1130320篇
  免费   77401篇
  国内免费   1674篇
耳鼻咽喉   15593篇
儿科学   36010篇
妇产科学   30059篇
基础医学   160434篇
口腔科学   30897篇
临床医学   100751篇
内科学   216441篇
皮肤病学   25147篇
神经病学   85922篇
特种医学   44685篇
外国民族医学   203篇
外科学   171843篇
综合类   22640篇
现状与发展   2篇
一般理论   362篇
预防医学   79494篇
眼科学   26242篇
药学   90137篇
  7篇
中国医学   2915篇
肿瘤学   69611篇
  2021年   8569篇
  2019年   8625篇
  2018年   12377篇
  2017年   9648篇
  2016年   10948篇
  2015年   12242篇
  2014年   16839篇
  2013年   24753篇
  2012年   33933篇
  2011年   35981篇
  2010年   21071篇
  2009年   19780篇
  2008年   33566篇
  2007年   35819篇
  2006年   36308篇
  2005年   34742篇
  2004年   33199篇
  2003年   31671篇
  2002年   30617篇
  2001年   60623篇
  2000年   62005篇
  1999年   51545篇
  1998年   13128篇
  1997年   11552篇
  1996年   11467篇
  1995年   10773篇
  1994年   9776篇
  1993年   9257篇
  1992年   38254篇
  1991年   36712篇
  1990年   36108篇
  1989年   34664篇
  1988年   31215篇
  1987年   30327篇
  1986年   28544篇
  1985年   26836篇
  1984年   19574篇
  1983年   16487篇
  1982年   9316篇
  1979年   17312篇
  1978年   11700篇
  1977年   10528篇
  1976年   9085篇
  1975年   10346篇
  1974年   11884篇
  1973年   11478篇
  1972年   10932篇
  1971年   10187篇
  1970年   9381篇
  1969年   9034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.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
4.
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   
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.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  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