全文获取类型
收费全文 | 1150464篇 |
免费 | 78711篇 |
国内免费 | 1712篇 |
专业分类
耳鼻咽喉 | 15930篇 |
儿科学 | 36634篇 |
妇产科学 | 30406篇 |
基础医学 | 163293篇 |
口腔科学 | 31205篇 |
临床医学 | 102701篇 |
内科学 | 220581篇 |
皮肤病学 | 25937篇 |
神经病学 | 87996篇 |
特种医学 | 45422篇 |
外国民族医学 | 205篇 |
外科学 | 174737篇 |
综合类 | 22824篇 |
现状与发展 | 2篇 |
一般理论 | 367篇 |
预防医学 | 80899篇 |
眼科学 | 26559篇 |
药学 | 91420篇 |
7篇 | |
中国医学 | 2944篇 |
肿瘤学 | 70818篇 |
出版年
2021年 | 8861篇 |
2019年 | 8879篇 |
2018年 | 12938篇 |
2017年 | 10035篇 |
2016年 | 11441篇 |
2015年 | 12784篇 |
2014年 | 17366篇 |
2013年 | 25594篇 |
2012年 | 35334篇 |
2011年 | 37412篇 |
2010年 | 21754篇 |
2009年 | 20344篇 |
2008年 | 34659篇 |
2007年 | 37006篇 |
2006年 | 37445篇 |
2005年 | 35806篇 |
2004年 | 34230篇 |
2003年 | 32608篇 |
2002年 | 31544篇 |
2001年 | 61059篇 |
2000年 | 62424篇 |
1999年 | 51986篇 |
1998年 | 13258篇 |
1997年 | 11656篇 |
1996年 | 11546篇 |
1995年 | 10863篇 |
1994年 | 9877篇 |
1993年 | 9326篇 |
1992年 | 38448篇 |
1991年 | 36939篇 |
1990年 | 36296篇 |
1989年 | 34853篇 |
1988年 | 31382篇 |
1987年 | 30498篇 |
1986年 | 28706篇 |
1985年 | 27003篇 |
1984年 | 19686篇 |
1983年 | 16606篇 |
1982年 | 9384篇 |
1979年 | 17427篇 |
1978年 | 11785篇 |
1977年 | 10607篇 |
1976年 | 9157篇 |
1975年 | 10450篇 |
1974年 | 11983篇 |
1973年 | 11559篇 |
1972年 | 11027篇 |
1971年 | 10269篇 |
1970年 | 9448篇 |
1969年 | 9103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.
Hassen Lena M. Albarrak Rana A. Albahlal Reem A. Alsaqabi Dimah K. Hassen Ikhlass M. Daghestani Maha H. Alqurtas Eman M. Alkhalaf Abdulaziz T. Bedaiwi Mohammed K. Omair Mohammed A. Almaghlouth Ibrahim A. 《Quality of life research》2022,31(11):3229-3239
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.
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
6.
7.
8.
9.
Patrick W. Keeley Mikayla C. Lebo Jordan D. Vieler Jason J. Kim Ace J. St. John Benjamin E. Reese 《The Journal of neuroscience》2021,41(1):103
Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.SIGNIFICANCE STATEMENT Different types of retinal neuron spread their processes across the surface of the retina to achieve a degree of dendritic coverage that is characteristic of each type. Many of these types achieve a constant coverage by varying their dendritic field area inversely with the local density of like-type neighbors. Here we report a population of retinal amacrine cells that do not develop dendritic arbors in relation to the spatial positioning of such homotypic neighbors; rather, this cell type modulates the extent of its dendritic branching when faced with a variable number of overlapping dendritic fields to approximate a uniformity in dendritic density across the retina. 相似文献