全文获取类型
收费全文 | 9936篇 |
免费 | 1124篇 |
国内免费 | 188篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 218篇 |
妇产科学 | 99篇 |
基础医学 | 920篇 |
口腔科学 | 146篇 |
临床医学 | 1212篇 |
内科学 | 1343篇 |
皮肤病学 | 113篇 |
神经病学 | 1693篇 |
特种医学 | 549篇 |
外国民族医学 | 1篇 |
外科学 | 697篇 |
综合类 | 1461篇 |
现状与发展 | 2篇 |
一般理论 | 3篇 |
预防医学 | 814篇 |
眼科学 | 94篇 |
药学 | 927篇 |
8篇 | |
中国医学 | 570篇 |
肿瘤学 | 321篇 |
出版年
2023年 | 152篇 |
2022年 | 205篇 |
2021年 | 468篇 |
2020年 | 490篇 |
2019年 | 457篇 |
2018年 | 416篇 |
2017年 | 434篇 |
2016年 | 423篇 |
2015年 | 453篇 |
2014年 | 752篇 |
2013年 | 759篇 |
2012年 | 602篇 |
2011年 | 629篇 |
2010年 | 485篇 |
2009年 | 483篇 |
2008年 | 430篇 |
2007年 | 435篇 |
2006年 | 406篇 |
2005年 | 340篇 |
2004年 | 285篇 |
2003年 | 279篇 |
2002年 | 216篇 |
2001年 | 166篇 |
2000年 | 137篇 |
1999年 | 138篇 |
1998年 | 91篇 |
1997年 | 105篇 |
1996年 | 65篇 |
1995年 | 87篇 |
1994年 | 82篇 |
1993年 | 71篇 |
1992年 | 52篇 |
1991年 | 59篇 |
1990年 | 66篇 |
1989年 | 50篇 |
1988年 | 37篇 |
1987年 | 34篇 |
1986年 | 36篇 |
1985年 | 62篇 |
1984年 | 57篇 |
1983年 | 30篇 |
1982年 | 39篇 |
1981年 | 30篇 |
1980年 | 37篇 |
1979年 | 19篇 |
1978年 | 20篇 |
1977年 | 27篇 |
1976年 | 11篇 |
1975年 | 14篇 |
1974年 | 9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.
Hypomineralized enamel may be found in connection with the condition molar incisor hypomineralization (MIH), which has a prevalence of around 15% in most parts of the world. Molar incisor hypomineralization is associated with extensive objective and subjective problems, such as hypersensitivity of the affected teeth, enamel breakdown, and problems with retention of restorations. The etiology behind MIH has not yet been elucidated, but a number of possible factors, which affect the same or different functions of ameloblasts during their different stages of maturation, have been suggested. The aim of this study was to utilize multi‐nuclear, solid‐state nuclear magnetic resonance (ss‐NMR) and time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS) to elucidate any differences, at a molecular level, between enamel powder prepared from normal, healthy teeth and enamel powder prepared from teeth diagnosed with MIH. 31P and 23Na ss‐NMR confirmed the presence of and two different Na+ sites in hypomineralized enamel, suggesting a heterogeneous chemical composition. The content of organic components was higher in hypomineralized enamel, as shown by both 13C ss‐NMR and ToF‐SIMS, indicating the presence of higher numbers of proteins and phospholipids. The interplay between both is necessary for the formation and mineralization of enamel, which might be disturbed or halted in hypomineralized enamel. 相似文献
4.
C. Jiamton N. Ratreprasatsuk R. Jarayabhand A. Kritsaneephaiboon T. Apivatthakakul 《Clinical anatomy (New York, N.Y.)》2019,32(2):176-182
The aim of this study was to determine the feasibility of applying MIPO of the humerus via the posterior approach and to observe the tension of the radial nerve in different elbow positions. Two separate incisions were made on the posterior aspect of the humerus in ten fresh cadavers (20 humeri). The radial nerve was identified at the proximal incision and the distances through which the nerve could be elevated from the bone with the elbow in flexion and extension were measured. A 10‐hole extra‐articular distal humeral locking compression plate was inserted and fixed through the submuscular tunnel. The tunnel was then explored to identify any entrapment of the radial nerve and to observe the anatomical relationship of the radial nerve to the plate and bone. There was no entrapment of the radial nerve or its branches. The distances through which the radial nerve could be elevated were greater with the elbow in extension than in flexion (P < 0.01). The radial nerve crossed the medial and lateral borders of the posterior surface of the humerus at 80.1–132 mm (average 104.7 mm) and 116.6–175.5 mm (average 142.7 mm) of its total length, respectively. The axillary nerve was located at 38.7–61.7 mm (average 47.9 mm) of total humeral length. MIPO of the humerus using the posterior approach is an alternative option for treating distal humeral shaft fracture. The risk of radial nerve injury can be minimized by careful dissection in the proximal incision. Clin. Anat. 32:176–182, 2019. © 2018 Wiley Periodicals, Inc. 相似文献
5.
Lise Barlebo Ahlborn Olga
strup 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2019,127(5):329-336
Circulating tumor DNA (ctDNA) refers to the fraction of cell‐free DNA in a patient's blood originating from tumor cells. Increased knowledge about tumor genomics, improvements in targeted therapies, and accompanying advances in DNA‐sequencing technologies have increased the interest in using ctDNA as a minimally invasive tool in cancer diagnostics and treatment. Especially, early tumor detection including identification of minimal residual disease and stratification of adjuvant therapy are promising approaches. Also, ctDNA showed to be reliable in treatment monitoring and can be used to assess therapy resistance due to the broad variety of tumor subclones captured in ctDNA. Therefore, using ctDNA in the clinical setting has the potential to improve therapeutic outcomes. In the present review, we summarize the status of ctDNA in oncology with focus of being an alternative to tissue biopsies in early detection and treatment monitoring. 相似文献
6.
7.
8.
9.
Objective
To empirically assess the effect of adopting Affordable Care Act's Community First Choice (CFC) option on overall state home and community-based services (HCBS) expenditures as well as distribution of HCBS expenditures across different HCBS mechanisms. We also explore the heterogeneous effect of CFC across adopting states.Data Source
We used data from the Medicaid Long Term Services and Support (LTSS) expenditure reports prepared by Truven Analytics and Mathematica for the Centers for Medicare & Medicaid Services from 2008–2018 for all 48 states and the District of Columbia.Study Design
An event-study difference-in-differences model was used to estimate the effect of CFC on HCBS expenditures using Medicaid LTSS expenditure reports from 2008–2018. We also employ the synthetic control method to unmask heterogeneity across CFC adopting states using data from 2008–2018.Data Collection/Extraction Methods
Not applicable.Principal Findings
Overall, CFC was not associated with a change in HCBS expenditures per capita or HCBS expenditures as a proportion of LTSS expenditures. However, there appears to be an increase in HCBS expenditures among states that were institutionally-oriented prior to CFC adoption. Additionally, CFC adoption was associated with an overall decrease in expenditures in alternative HCBS mechanisms (Personal Care Services State Plan Option and 1915(c) waivers), suggesting potential substitution across overlapping programs.Conclusion
Results indicate heterogeneity across states adopting CFC. More institutionally-oriented states appear to use CFC to expand HCBS. In contrast, more HCBS-oriented states appear to employ CFC to strategically restructure their overall portfolio and processes. 相似文献10.
《Saudi Pharmaceutical Journal》2022,30(6):679-692
Croton stellatopilosus (Plaunoi) leaves accumulate several diterpenes and possess various pharmacological activities. The present study aimed to prepare, characterize and assess the antibacterial activity of inclusion complexes prepared by mixing plaunotol (PL) or plaunoi extract (PE) with cyclodextrins (CD), including α-CD, β-CD, γ-CD, and hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complexes were characterized using SEM, XRD, DSC, and FT-IR and evaluated for aqueous solubility and thermal stability. The PL and PE lyophilized complexes with HP-β-CD were further evaluated for their antibacterial activity against acne-causing bacteria. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of PL, PE, and the inclusion complexes evaluated using the agar dilution method revealed that the MIC and MBC values of the inclusion complexes were lower than those of PL or PE alone. Interestingly, the complexes had a synergistic activity with clindamycin after testing with checkerboard assay. The hydrogel containing the inclusion complex and clindamycin were assessed for antibacterial activity using the agar well diffusion method. The results indicated that the hydrogels showed significant inhibition of bacterial growth. In conclusion, the prepared solid dispersion of PL or PE with HP-β-CD could enhance antibacterial activity by increasing the drug solubility. The hydrogels containing PL or PE complex and clindamycin could be considered as a candidate for the treatment of acne vulgaris. 相似文献