全文获取类型
收费全文 | 72398篇 |
免费 | 5444篇 |
国内免费 | 438篇 |
专业分类
耳鼻咽喉 | 734篇 |
儿科学 | 1777篇 |
妇产科学 | 1926篇 |
基础医学 | 9040篇 |
口腔科学 | 1730篇 |
临床医学 | 7295篇 |
内科学 | 16242篇 |
皮肤病学 | 946篇 |
神经病学 | 5621篇 |
特种医学 | 2185篇 |
外国民族医学 | 2篇 |
外科学 | 11095篇 |
综合类 | 1327篇 |
现状与发展 | 2篇 |
一般理论 | 105篇 |
预防医学 | 5693篇 |
眼科学 | 2047篇 |
药学 | 5334篇 |
4篇 | |
中国医学 | 332篇 |
肿瘤学 | 4843篇 |
出版年
2023年 | 383篇 |
2022年 | 605篇 |
2021年 | 1433篇 |
2020年 | 903篇 |
2019年 | 1292篇 |
2018年 | 1554篇 |
2017年 | 1059篇 |
2016年 | 1166篇 |
2015年 | 1446篇 |
2014年 | 2154篇 |
2013年 | 3308篇 |
2012年 | 4444篇 |
2011年 | 4890篇 |
2010年 | 2812篇 |
2009年 | 2566篇 |
2008年 | 4550篇 |
2007年 | 4683篇 |
2006年 | 4522篇 |
2005年 | 4591篇 |
2004年 | 4268篇 |
2003年 | 3801篇 |
2002年 | 3727篇 |
2001年 | 979篇 |
2000年 | 829篇 |
1999年 | 897篇 |
1998年 | 804篇 |
1997年 | 660篇 |
1996年 | 528篇 |
1995年 | 551篇 |
1994年 | 510篇 |
1993年 | 487篇 |
1992年 | 651篇 |
1991年 | 600篇 |
1990年 | 501篇 |
1989年 | 491篇 |
1988年 | 449篇 |
1987年 | 436篇 |
1986年 | 385篇 |
1985年 | 455篇 |
1984年 | 476篇 |
1983年 | 420篇 |
1982年 | 553篇 |
1981年 | 459篇 |
1980年 | 501篇 |
1979年 | 324篇 |
1978年 | 337篇 |
1977年 | 335篇 |
1976年 | 278篇 |
1975年 | 305篇 |
1974年 | 261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.
Dongbing Lai Emma C. Johnson Sarah Colbert Gayathri Pandey Grace Chan Lance Bauer Meredith W. Francis Victor Hesselbrock Chella Kamarajan John Kramer Weipeng Kuang Sally Kuo Samuel Kuperman Yunlong Liu Vivia McCutcheon Zhiping Pang Martin H. Plawecki Marc Schuckit Jay Tischfield Leah Wetherill Yong Zang Howard J. Edenberg Bernice Porjesz Arpana Agrawal Tatiana Foroud 《Alcoholism, clinical and experimental research》2022,46(3):374-383
3.
Rajendrababu Sharmila Puthuran George Varghese Alia Laxmi Ananya Uduman Mohammed Sithiq Wijesinghe Hiruni Kaushalya 《International ophthalmology》2022,42(8):2609-2618
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
4.
Qiangsheng He Chongfei Huang Xiwen Qin Yuanyuan Yu Di Tang Junjie Huang Zi Chong Kuo Yuyao Ling Deli Mao Bin Xia Wenjing Li Kuiqing Lu Man Yang Yulong He Wenbo Meng Jinqiu Yuan Yihang Pan 《International journal of cancer. Journal international du cancer》2023,153(5):942-949
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes. 相似文献
5.
6.
Hsiao-Hsuan Kuo Ran Fan Nina Dvorina Andres Chiesa-Vottero William M. Baldwin III 《Journal of the American Society of Nephrology : JASN》2015,26(4):855-863
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses. 相似文献
7.
8.
9.
10.