全文获取类型
收费全文 | 821篇 |
免费 | 51篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 15篇 |
妇产科学 | 46篇 |
基础医学 | 133篇 |
口腔科学 | 7篇 |
临床医学 | 83篇 |
内科学 | 145篇 |
皮肤病学 | 42篇 |
神经病学 | 73篇 |
特种医学 | 31篇 |
外科学 | 115篇 |
综合类 | 5篇 |
一般理论 | 5篇 |
预防医学 | 49篇 |
眼科学 | 4篇 |
药学 | 44篇 |
肿瘤学 | 73篇 |
出版年
2023年 | 10篇 |
2022年 | 11篇 |
2021年 | 34篇 |
2020年 | 28篇 |
2019年 | 29篇 |
2018年 | 31篇 |
2017年 | 27篇 |
2016年 | 36篇 |
2015年 | 30篇 |
2014年 | 41篇 |
2013年 | 48篇 |
2012年 | 61篇 |
2011年 | 68篇 |
2010年 | 55篇 |
2009年 | 39篇 |
2008年 | 46篇 |
2007年 | 44篇 |
2006年 | 36篇 |
2005年 | 44篇 |
2004年 | 31篇 |
2003年 | 34篇 |
2002年 | 37篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1974年 | 3篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有877条查询结果,搜索用时 250 毫秒
81.
Hiller ML Leukefeld CG Garrity TF Godlaski T Schoeneberger M Townsend M Hascal K 《Journal of psychoactive drugs》2007,39(1):59-68
Several national evaluations have been conducted since the late 1960s that have assessed the effectiveness of publicly-funded substance abuse treatment in the United States. These studies, however, have focused principally on urban-based treatment programs, and it is unclear whether findings from urban programs can be replicated in outcome studies of programs in rural areas. The current study, therefore, examined the treatment outcomes of clients admitted to one of several short-term inpatient or outpatient drug-free treatment agencies in rural Kentucky. Findings showed that treatment was associated with reductions in drug use and criminality during a six-month follow-up interval. Employment status also improved significantly, and health services utilization was reduced. The similarity between the current findings and findings from national outcome studies of urban-based treatment programs is discussed. 相似文献
82.
83.
Standardized and transparent priority setting in medicine, desirable as it is, will generally exacerbate inter-temporal equity problems arising from changes in treatment priorities: when can it be fair that the treatment of already waiting patients who would have had priority under an established system should be postponed (withheld) for an extended period of time to advance the treatment of others under a reformed system? The reform of the Eurotransplant system of priority setting in kidney allocation (ETKAS), which is in many respects ideal, is a case in point. To give due weight to new medical knowledge, waiting time after the onset of end state renal failure should change from a priority-enhancing to a priority-reducing factor. Since those who have gained in priority by waiting under the present system would be set back under the new, severe problems of transitional justice must be overcome when responding to advances in medical knowledge. The paper explores conceptually some possible ways of rule change and indicates their general relevance from an ethical and a practical point of view for future problems of medical resource allocation under transparent, standardized priority-setting rules. 相似文献
84.
Marlies De Boeck Sonia Lardau Jean-Pierre Buchet Micheline Kirsch-Volders Dominique Lison 《癌变.畸变.突变》2001,13(4)
An increased lung cancer risk is associated with occupational exposure to mixtures of cobalt metal and metallic carbide particles, but when exposure is to cobalt metal alone. The current TLV-TWA was established without consideration of carcinogenicity data. The present study was designed to assess whether an increased cancer risk can be detected in workers currently exposed on average to the TLV-TWA (20 μg/m3). 相似文献
85.
Problem: Non-response and non-usable response were found in population surveys on valuation of health states. If non-response is selective regarding valuations, then generalization of the resulting values to the whole survey population is not permitted. This could limit the use of empirical utility values in resource allocation in health care. Methods: Response behaviour of a sample of 1400 from the Dutch general population to the mailed EuroQolc-questionnaire was analyzed by four methods. I. Phoning resolute non-respondents; II. comparison of zip code characteristics of respondents and non-respondents (because individual data on background characteristics were not available for the non-respondents); III. analysis of response over time (wave-analysis); IV: comparison of background variables of successful (less than two valuations missing) and unsuccessful respondents, combined with analysis of the effect of these background variables on valuations. Results: No indications for selective non-response were found, although the phenomenon appeared hard to investigate. The successful response came from a slightly younger and better educated subsample. However, a general influence of age and educational level on valuations could not be shown. This finding is consistent with the literature. Conclusion: Although the existence of selective non-response cannot be excluded, its relevance can be considered to be small. This finding is encouraging for the use of empirical utility values in allocative decisions. 相似文献
86.
van der Welle ME Roelofs JG Op Den Camp HJ Lamers LP 《Environmental toxicology and chemistry / SETAC》2007,26(4):686-694
Metal pollution can be a serious threat to ecosystems at a global scale. Although the bioavailability of potentially toxic metals is determined by many biotic and abiotic factors, including pH and redox potential, total metal concentrations in the soil are used widely to assess or predict toxicity. In the present study we tested the effect of desiccation of soils differing in acidification potential and total heavy metal contamination on the growth and metal uptake of three typical, common wetland species: Caltha palustris, Juncus effusus, and Rumex hydrolapathum. We found that plant growth in wet soils mainly was determined by nutrient availability, though in dry soils the combined effects of acidification and increased metal availability prevailed. Metal uptake under anaerobic conditions was best predicted by the acidification potential (sediment S/[Ca + Mg] ratio), not by total metal concentrations. We propose that this is related to radial oxygen loss by wetland plant roots, which leads to acidification of the rhizosphere. Under aerobic conditions, plant metal uptake was best predicted by the amount of CaCl2-extractable metals. We conclude that total metal concentrations are not suitable for predicting bioavailability and that the above diagnostic parameters will provide insight into biogeochemical processes involved in toxicity assessment and soil policy. 相似文献
87.
Sprong T Pickkers P Geurts-Moespot A van der Ven-Jongekrijg J Neeleman C Knaup M Leroy D Calandra T van der Meer JW Sweep F van Deuren M 《Shock (Augusta, Ga.)》2007,27(5):482-487
Macrophage migration inhibitory factor (MIF) is a mediator of innate immunity and important in the pathogenesis of septic shock. Lipopolysaccharide (LPS) and tumor necrosis factor (TNF) alpha are reported to be inducers of MIF. We studied MIF and cytokines in vivo in patients with meningococcal disease, in human experimental endotoxemia, and in whole blood cultures using a newly developed sensitive and specific enzyme-linked immunosorbent assay. Twenty patients with meningococcal disease were investigated. For the human endotoxemia model, 8 healthy volunteers were intravenously injected with 2 ng/kg Escherichia coli LPS. Whole blood from healthy volunteers was incubated with LPS or heat-killed meningococci. Macrophage migration inhibitory factor concentration in blood was increased during meningococcal disease and highest in the patients presenting with shock compared with patients without shock. Plasma concentration of MIF correlated with disease severity, the presence of shock and with the cytokines interleukin (IL) 1beta, IL-10, IL-12, and vascular endothelial growth factor, but not with TNF-alpha. MIF was not detected in blood in experimental endotoxemia, nor after stimulation of whole blood with LPS or meningococci, although high levels of TNF-alpha were seen in both models. In conclusion, MIF is increased in patients with meningococcal disease and highest in the presence of shock. Macrophage migration inhibitory factor cannot be detected in a human endotoxemia model and is not produced by whole blood cells incubated with LPS or meningococci. 相似文献
88.
89.
Alternative Ways to Quantify Sustained Remission: Applying the Continuity Rewarded Score and Patient Vector Graph 下载免费PDF全文
90.
Marlies Ostermann Jessica Lo Michael Toolan Emma Tuddenham Barnaby Sanderson Katie Lei John Smith Anna Griffiths Ian Webb James Coutts John Chambers Paul Collinson Janet Peacock David Bennett David Treacher 《Critical care (London, England)》2014,18(2):R62