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   1806777篇
  免费   166302篇
  国内免费   3643篇
耳鼻咽喉   25825篇
儿科学   59213篇
妇产科学   51256篇
基础医学   248272篇
口腔科学   55890篇
临床医学   174763篇
内科学   358081篇
皮肤病学   40827篇
神经病学   152647篇
特种医学   72797篇
外国民族医学   477篇
外科学   277855篇
综合类   40404篇
现状与发展   43篇
一般理论   585篇
预防医学   141904篇
眼科学   41260篇
药学   130825篇
  3篇
中国医学   3192篇
肿瘤学   100603篇
  2018年   23613篇
  2017年   20417篇
  2016年   22730篇
  2015年   24595篇
  2014年   32670篇
  2013年   47074篇
  2012年   52126篇
  2011年   55025篇
  2010年   36368篇
  2009年   36212篇
  2008年   53157篇
  2007年   54885篇
  2006年   56519篇
  2005年   53751篇
  2004年   52135篇
  2003年   50024篇
  2002年   48933篇
  2001年   81247篇
  2000年   84340篇
  1999年   70751篇
  1998年   20789篇
  1997年   18963篇
  1996年   18784篇
  1995年   18145篇
  1994年   16659篇
  1993年   15648篇
  1992年   56743篇
  1991年   54907篇
  1990年   53562篇
  1989年   51827篇
  1988年   48105篇
  1987年   47404篇
  1986年   44998篇
  1985年   43705篇
  1984年   32841篇
  1983年   28333篇
  1982年   16857篇
  1981年   15072篇
  1979年   30944篇
  1978年   21556篇
  1977年   18267篇
  1976年   17135篇
  1975年   17995篇
  1974年   21906篇
  1973年   21002篇
  1972年   19154篇
  1971年   18060篇
  1970年   16570篇
  1969年   15516篇
  1968年   14172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.
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