全文获取类型
收费全文 | 159517篇 |
免费 | 14108篇 |
国内免费 | 407篇 |
专业分类
耳鼻咽喉 | 2076篇 |
儿科学 | 4473篇 |
妇产科学 | 2850篇 |
基础医学 | 22246篇 |
口腔科学 | 2809篇 |
临床医学 | 18296篇 |
内科学 | 31077篇 |
皮肤病学 | 2153篇 |
神经病学 | 14319篇 |
特种医学 | 5755篇 |
外国民族医学 | 10篇 |
外科学 | 23837篇 |
综合类 | 2529篇 |
一般理论 | 154篇 |
预防医学 | 15202篇 |
眼科学 | 3772篇 |
药学 | 11916篇 |
1篇 | |
中国医学 | 171篇 |
肿瘤学 | 10386篇 |
出版年
2023年 | 975篇 |
2022年 | 1541篇 |
2021年 | 3441篇 |
2020年 | 2056篇 |
2019年 | 3249篇 |
2018年 | 3824篇 |
2017年 | 2747篇 |
2016年 | 2916篇 |
2015年 | 3390篇 |
2014年 | 4763篇 |
2013年 | 6502篇 |
2012年 | 9815篇 |
2011年 | 10301篇 |
2010年 | 5566篇 |
2009年 | 5043篇 |
2008年 | 8452篇 |
2007年 | 8975篇 |
2006年 | 8434篇 |
2005年 | 8442篇 |
2004年 | 7741篇 |
2003年 | 7130篇 |
2002年 | 6689篇 |
2001年 | 3286篇 |
2000年 | 3209篇 |
1999年 | 3044篇 |
1998年 | 1828篇 |
1997年 | 1444篇 |
1996年 | 1324篇 |
1995年 | 1189篇 |
1994年 | 1191篇 |
1993年 | 1116篇 |
1992年 | 2338篇 |
1991年 | 2209篇 |
1990年 | 2066篇 |
1989年 | 2017篇 |
1988年 | 1913篇 |
1987年 | 1899篇 |
1986年 | 1807篇 |
1985年 | 1804篇 |
1984年 | 1560篇 |
1983年 | 1400篇 |
1982年 | 1069篇 |
1981年 | 938篇 |
1980年 | 793篇 |
1979年 | 1304篇 |
1978年 | 985篇 |
1977年 | 854篇 |
1976年 | 783篇 |
1974年 | 904篇 |
1973年 | 793篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
31.
32.
33.
Rebecca Carman Lesley Andrew Amanda Devine Jacques Oosthuizen 《Australian and New Zealand journal of public health》2019,43(6):563-569
Objective: To identify behavioural barriers of service provision within general practice that may be impacting the vaccination coverage rates of Aboriginal children in Perth, Western Australia (WA). Methods: A purposive developed survey was distributed to 316 general practices across Perth and three key informant interviews were conducted using a mixed‐methods approach. Results: Of the surveyed participants (n=101), 67.4% were unaware of the low vaccination coverage in Aboriginal children; 64.8% had not received cultural sensitivity training in their workplace and 46.8% reported having inadequate time to follow up overdue child vaccinations. Opportunistic vaccination was not routinely performed by 30.8% of participants. Key themes identified in the interviews were awareness, inclusion and cultural safety. Conclusion: Inadequate awareness of the current rates, in association with a lack of cultural safety training, follow‐up and opportunistic practice, may be preventing greater vaccination uptake in Aboriginal children in Perth. Cultural safety is a critical component of the acceptability and accessibility of services; lack of awareness may restrict the development of strategies designed to equitably address low coverage. Implications: The findings of this study provide an opportunity to raise awareness among clinicians in general practice and inform future strategies to equitably deliver targeted vaccination services to Aboriginal children. 相似文献
34.
35.
Susan C. Fox Jane A. May Natalia Dovlatova Jackie R. Glenn Andrew Johnson Ann E. White 《Platelets》2019,30(3):290-295
Measurement of P-selectin on activated platelets as a means of measuring platelet function utilizing the technology described here has the advantage of not requiring immediate access to specialist equipment and expertise. Blood samples are activated, fixed, stored, and transported to a central laboratory for flow cytometric analysis. Here we have compared P-selectin with other more traditional approaches to measuring platelet function in blood and/or platelet-rich plasma (PRP) from patients with acute coronary syndromes on treatment for at least 1 month with either aspirin and clopidogrel or aspirin with prasugrel. The comparators were light transmission aggregometry (LTA), VerifyNow and Multiplate aggregometry (for determining the effects of aspirin) and LTA, VerifyNow and Multiplate together with the BioCytex VASP phosphorylation assay (for the P2Y12 antagonists). The P-selectin Aspirin Test revealed substantial inhibition of platelet function in all but three of 96 patients receiving aspirin with clopidogrel and in none of 51 patients receiving aspirin and prasugrel. The results were very similar to those obtained using LTA. There was only one patient with high residual platelet aggregation and low P-selectin expression. The same patients identified as “non-responders” to aspirin also presented with the highest residual platelet activity as measured using the VerifyNow system, although not quite as well separated from the other values. With the Multiplate test only one of these patients clearly stood out from the others. The results obtained using the P-selectin P2Y12 Test in 102 patients taking aspirin and clopidogrel were similar to the more traditional approaches in that a wide scatter of results was obtained. Generally, high values seen with the P-selectin P2Y12 Test were also high with the LTA, VerifyNow, Multiplate, and BioCytex VASP P2Y12 Tests. Similarly, low residual platelet function using the P2Y12 test was seen irrespective of the testing procedure used. However, there were differences in some patients. Prasugrel was always more effective than clopidogrel in inhibiting platelet function with none of 56 patients (P-selectin and VerifyNow), only 2 of 56 patients (Multiplate) and only 3 of 56 patients (Biocytex VASP) demonstrating high on-treatment residual platelet reactivity (HRPR) defined using previously published cut-off values. The exception was LTA where there were 11 of 56 patients with HRPR. It remains to be seen which experimental approach provides the most useful information regarding outcomes after adjusting therapies in treated patients. 相似文献
36.
Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed. 相似文献
37.
Lesley A. Inker Morgan E. Grams Andrew S. Levey Josef Coresh Massimo Cirillo John F. Collins Ron T. Gansevoort Orlando M. Gutierrez Takayuki Hamano Gunnar H. Heine Shizukiyo Ishikawa Sun Ha Jee Florian Kronenberg Martin J. Landray Katsuyuki Miura Girish N. Nadkarni Carmen A. Peralta Dietrich Rothenbacher Mark Woodward 《American journal of kidney diseases》2019,73(2):206-217
38.
Rotary ventricular assist devices (VADs) are less sensitive to preload than the healthy heart, resulting in inadequate flow regulation in response to changes in patient cardiac demand. Starling‐like physiological controllers (SLCs) have been developed to automatically regulate VAD flow based on ventricular preload. An SLC consists of a cardiac response curve (CRC) which imposes a nonlinear relationship between VAD flow and ventricular preload, and a venous return line (VRL) which determines the return path of the controller. This study investigates the importance of a physiological VRL in SLC of dual rotary blood pumps for biventricular support. Two experiments were conducted on a physical mock circulation loop (MCL); the first compared an SLC with an angled physiological VRL (SLC‐P) against an SLC with a vertical VRL (SLC‐V). The second experiment quantified the benefit of a dynamic VRL, represented by a series of specific VRLs, which could adapt to different circulatory states including changes in pulmonary (PVR) and systemic (SVR) vascular resistance versus a fixed physiological VRL which was calculated at rest. In both sets of experiments, the transient controller responses were evaluated through reductions in preload caused by the removal of fluid from the MCL. The SLC‐P produced no overshoot or oscillations following step changes in preload, whereas SLC‐V produced 0.4 L/min (12.5%) overshoot for both left and right VADs. Additionally, the SLC‐V had increased settling time and reduced controller stability as evidenced by transient controller oscillations. The transient results comparing the specific and standard VRLs demonstrated that specific VRL rise times were improved by between 1.2 and 4.7 s ( = 3.05 s), while specific VRL settling times were improved by between 2.8 and 16.1 seconds ( = 8.38 s) over the standard VRL. This suggests only a minor improvement in controller response time from a dynamic VRL compared to the fixed VRL. These results indicate that the use of a fixed physiologically representative VRL is adequate over a wide variety of physiological conditions. 相似文献
39.
40.
Children with autism spectrum disorder (ASD) demonstrate limited playfulness. Their difficulty engaging in meaningful interaction with others renders playful engagement in social interactions a challenge. Although little direct evidence exists regarding the promotion of these children’s playful engagement, links can be established with many traits cited in play and social interaction studies. This paper presents the results of a conceptual clarification exercise regarding the key behaviours associated with the construct of playful engagement in preschool-aged children with ASD. Behaviours were identified based on hallmark deficits in early social interactions and play of children with ASD. The analysis revealed the following behaviours: positive affect, engagement, imitation, joint attention, initiation of social interaction, social responsiveness, flexibility, child’s laughter in funny situations and giving and reading non-verbal cues. In conclusion, a conceptually coherent stage has been set for exploring the literature regarding interventions to promote the playful engagement of preschool-aged children with ASD. 相似文献