329 research outputs found

    Modeling hospital infrastructure by optimizing quality, accessibility and efficiency via a mixed integer programming model

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    BACKGROUND: The majority of curative health care is organized in hospitals. As in most other countries, the current 94 hospital locations in the Netherlands offer almost all treatments, ranging from rather basic to very complex care. Recent studies show that concentration of care can lead to substantial quality improvements for complex conditions and that dispersion of care for chronic conditions may increase quality of care. In previous studies on allocation of hospital infrastructure, the allocation is usually only based on accessibility and/or efficiency of hospital care. In this paper, we explore the possibilities to include a quality function in the objective function, to give global directions to how the ‘optimal’ hospital infrastructure would be in the Dutch context. METHODS: To create optimal societal value we have used a mathematical mixed integer programming (MIP) model that balances quality, efficiency and accessibility of care for 30 ICD-9 diagnosis groups. Typical aspects that are taken into account are the volume-outcome relationship, the maximum accepted travel times for diagnosis groups that may need emergency treatment and the minimum use of facilities. RESULTS: The optimal number of hospital locations per diagnosis group varies from 12-14 locations for diagnosis groups which have a strong volume-outcome relationship, such as neoplasms, to 150 locations for chronic diagnosis groups such as diabetes and chronic obstructive pulmonary disease (COPD). CONCLUSIONS: In conclusion, our study shows a new approach for allocating hospital infrastructure over a country or certain region that includes quality of care in relation to volume per provider that can be used in various countries or regions. In addition, our model shows that within the Dutch context chronic care may be too concentrated and complex and/or acute care may be too dispersed. Our approach can relatively easily be adopted towards other countries or regions and is very suitable to perform a ‘what-if’ analysis

    Clinical longevity of intracoronal restorations made of gold, lithium disilicate, leucite, and indirect resin composite:a systematic review and meta-analysis

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    OBJECTIVES: The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium disilicate, leucite, and indirect composite materials.MATERIAL AND METHODS: This systematic review and meta-analysis were conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. The protocol for this study was registered in PROSPERO (registration number: CRD42021233185). A comprehensive literature search was conducted across various databases and sources, including PubMed/Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and gray literature. A total of 7826 articles were screened on title and abstract. Articles were not excluded based on the vitality of teeth, the language of the study, or the observation period. The risk difference was utilized for the analyses, and a random-effects model was applied. All analyses were conducted with a 95% confidence interval (95% CI). The calculated risk differences were derived from the combined data on restoration survival and failures obtained from each individual article. The presence of heterogeneity was assessed using the I2 statistic, and if present, the heterogeneity of the data in the articles was evaluated using the non-parametric chi-squared statistic (p &lt; 0.05).RESULTS: A total of 12 eligible studies were selected, which included 946 restorations evaluated over a minimum observation period of 1 year and a maximum observation period of 7 years. Results of the meta-analysis indicated that intracoronal indirect resin composite restorations have an 18% higher rate of failure when compared to intracoronal gold restorations over 5-7 years of clinical service (risk difference =  - 0.18 [95% CI: - 0.27, - 0.09]; p = .0002; I2 = 0%). The meta-analysis examining the disparity in survival rates between intracoronal gold and leucite restorations could not be carried out due to methodological differences in the studies.CONCLUSIONS: According to the currently available evidence, medium-quality data indicates that lithium disilicate and indirect composite materials demonstrate comparable survival rates in short-term follow-up. Furthermore, intracoronal gold restorations showed significantly higher survival rates, making them a preferred option over intracoronal indirect resin-composite restorations. Besides that, the analysis revealed no statistically significant difference in survival rates between leucite and indirect composite restorations. The short observation period, limited number of eligible articles, and low sample size of the included studies were significant limitations.CLINICAL SIGNIFICANCE: Bearing in mind the limitations of the reviewed literature, this systematic review and meta-analysis help clinicians make evidence-based decisions on how to restore biomechanically compromised posterior teeth.</p

    Classification of bicovariant differential calculi on the Jordanian quantum groups GL_{g,h}(2) and SL_{h}(2) and quantum Lie algebras

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    We classify all 4-dimensional first order bicovariant calculi on the Jordanian quantum group GL_{h,g}(2) and all 3-dimensional first order bicovariant calculi on the Jordanian quantum group SL_{h}(2). In both cases we assume that the bicovariant bimodules are generated as left modules by the differentials of the quantum group generators. It is found that there are 3 1-parameter families of 4-dimensional bicovariant first order calculi on GL_{h,g}(2) and that there is a single, unique, 3-dimensional bicovariant calculus on SL_{h}(2). This 3-dimensional calculus may be obtained through a classical-like reduction from any one of the three families of 4-dimensional calculi on GL_{h,g}(2). Details of the higher order calculi and also the quantum Lie algebras are presented for all calculi. The quantum Lie algebra obtained from the bicovariant calculus on SL_{h}(2) is shown to be isomorphic to the quantum Lie algebra we obtain as an ad-submodule within the Jordanian universal enveloping algebra U_{h}(sl(2)) and also through a consideration of the decomposition of the tensor product of two copies of the deformed adjoint module. We also obtain the quantum Killing form for this quantum Lie algebra.Comment: 33 pages, AMSLaTeX, misleading remark remove

    A reforma do estado dos anos 90: lógica e mecanismos de controle

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    Demostración de resultado económico: percepción del comando da aeronáutica de Brasil

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    No ano de 2010, uma alteração no quadro normativo brasileiro introduziu a Demonstração do Resultado Econômico (DRE) para o setor público, que busca comparar custos internos de produção com valores de mercado, segundo o conceito de custo de oportunidade. Este estudo procura analisar as possíveis respostas estratégicas dos gestores , buscando perceber se a cultura contábil existente no País permite a aceitação do novo instrumento. Por meio das percepções dos agentes públicos do Comando da Aeronáutica (Comaer), no Brasil, conclui-se que a resposta estratégica dos entrevistados tende para a atitude de aceitação da nova rotina, demonstrando traços de menor conservadorismo e maior interesse pela evidenciação de resultados.In 2010, a change in the Brazilian accounting regulatory framework introduced the Demonstração do Resultado Econômico (DRE) [Economic Income Statement] for the public sector, which seeks to compare the internal costs of production to market values, according to the concept of opportunity cost. This study aims to analyse the possible strategic responses of managers and tries to understand if the existing accounting culture in Brazil facilitates the introduction of the new statement. By means of perceptions of officials of the Aeronautical Command (Comaer), in Brazil, it is possible to conclude that the strategic response of respondents is closer to acceptance of the new routine, showing traces of less conservatism and greater interest for displaying results.En el año 2010, una modificación del cuadro normativo brasileño introdujo la Demostración del Resultado Económico (DRE) para el sector público, que busca comparar los costos internos de producción con los valores del mercado, según el concepto de costo de oportunidad. Este estudio tiene como objetivo analizar las posibles respuestas estratégicas de los gestores, con el fin de percibir si la cultura contable existente en el país permite la aceptación del nuevo instrumento. Por medio de las percepciones de los agentes públicos del Comando da Aeronáutica (Comaer), en Brasil, se concluyó que la respuesta estratégica de los entrevistados tiende a aceptar la nueva rutina, mostrando rasgos de menos conservadurismo y más interés por la manifestación de resultados.Fundação para a Ciência e a Tecnologia (FCT

    Coseismic fault lubrication by viscous deformation

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    Despite the hazard posed by earthquakes, we still lack fundamental understanding of the processes that control fault lubrication behind a propagating rupture front and enhance ground acceleration. Laboratory experiments show that fault materials dramatically weaken when sheared at seismic velocities (>0.1 m s−1). Several mechanisms, triggered by shear heating, have been proposed to explain the coseismic weakening of faults, but none of these mechanisms can account for experimental and seismological evidence of weakening. Here we show that, in laboratory experiments, weakening correlates with local temperatures attained during seismic slip in simulated faults for diverse rock-forming minerals. The fault strength evolves according to a simple, material-dependent Arrhenius-type law. Microstructures support this observation by showing the development of a principal slip zone with textures typical of sub-solidus viscous flow. We show evidence that viscous deformation (at either sub- or super-solidus temperatures) is an important, widespread and quantifiable coseismic lubrication process. The operation of these highly effective fault lubrication processes means that more energy is then available for rupture propagation and the radiation of hazardous seismic waves
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