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   1685846篇
  免费   160926篇
  国内免费   3509篇
耳鼻咽喉   23795篇
儿科学   55159篇
妇产科学   48352篇
基础医学   230078篇
口腔科学   51907篇
临床医学   165005篇
内科学   335540篇
皮肤病学   37115篇
神经病学   141246篇
特种医学   67987篇
外国民族医学   474篇
外科学   259845篇
综合类   39916篇
现状与发展   43篇
一般理论   550篇
预防医学   135151篇
眼科学   38376篇
药学   122220篇
  2篇
中国医学   2985篇
肿瘤学   94535篇
  2018年   20940篇
  2017年   18306篇
  2016年   19955篇
  2015年   22184篇
  2014年   29968篇
  2013年   42244篇
  2012年   45920篇
  2011年   47851篇
  2010年   32418篇
  2009年   33481篇
  2008年   46066篇
  2007年   47383篇
  2006年   49251篇
  2005年   46603篇
  2004年   45481篇
  2003年   43296篇
  2002年   42287篇
  2001年   77443篇
  2000年   79435篇
  1999年   68001篇
  1998年   19643篇
  1997年   18046篇
  1996年   18038篇
  1995年   17561篇
  1994年   16139篇
  1993年   15113篇
  1992年   56189篇
  1991年   54418篇
  1990年   53079篇
  1989年   51365篇
  1988年   47717篇
  1987年   46924篇
  1986年   44636篇
  1985年   43168篇
  1984年   32298篇
  1983年   27863篇
  1982年   16363篇
  1981年   14620篇
  1979年   30565篇
  1978年   21188篇
  1977年   17902篇
  1976年   16800篇
  1975年   17645篇
  1974年   21585篇
  1973年   20768篇
  1972年   18945篇
  1971年   17819篇
  1970年   16340篇
  1969年   15306篇
  1968年   13968篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
Kinase alterations are increasingly recognised as oncogenic drivers in mesenchymal tumours. Infantile fibrosarcoma and the related renal tumour, congenital mesoblastic nephroma, were among the first solid tumours shown to harbour recurrent tyrosine kinase fusions, with the canonical ETV6::NTRK3 fusion identified more than 20 years ago. Although targeted testing has long been used in diagnosis, the advent of more robust sequencing techniques has driven the discovery of kinase alterations in an array of mesenchymal tumours. As our ability to identify these genetic alterations has improved, as has our recognition and understanding of the tumours that harbour these alterations. Specifically, this study will focus upon mesenchymal tumours harbouring NTRK or other kinase alterations, including tumours with an infantile fibrosarcoma-like appearance, spindle cell tumours resembling lipofibromatosis or peripheral nerve sheath tumours and those occurring in adults with a fibrosarcoma-like appearance. As publications describing the histology of these tumours increase so, too, do the variety kinase alterations reported, now including NTRK1/2/3, RET, MET, RAF1, BRAF, ALK, EGFR and ABL1 fusions or alterations. To date, these tumours appear locally aggressive and rarely metastatic, without a clear link between traditional features used in histological grading (e.g. mitotic activity, necrosis) and outcome. However, most of these tumours are amenable to new targeted therapies, making their recognition of both diagnostic and therapeutic import. The goal of this study is to review the clinicopathological features of tumours with NTRK and other tyrosine kinase alterations, discuss the most common differential diagnoses and provide recommendations for molecular confirmation with associated treatment implications.  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