150 research outputs found

    Intrathecal drug delivery systems for the management of chronic non-cancer pain : a systematic review of economic evaluations

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    Background: Intrathecal drug delivery (ITDD) systems are one of a limited number of management options for chronic non-cancer pain, cancer pain and spasticity. Concerns over their effectiveness and high initial costs led NHS England to decommission ITDD for patients with chronic non-cancer pain. However, the extent to which this decision is in line with existing economic evidence is unclear. The aim of this systematic review is to identify and review the existing evidence on the cost-effectiveness of ITDD for chronic non-cancer pain. Methods: Full and partial economic evaluations on ITDD were identified through systematic searches in MEDLINE, EMBASE, Web of Science and the National Health Service Centre for Reviews and Dissemination databases. Database searches were complemented by hand searching of reference lists of relevant studies and searches of grey literature. Study selection was carried out by two assessors, independently. Study quality assessment was performed to inform critical appraisal of health economics studies. Data were extracted using a data extraction form developed for this study. Results: 4464 unique studies were identified, of which seven met the inclusion criteria. With the exception of one study, the studies found ITDD to be either cost-saving or cost-effective compared to conventional medical management. ITDD becomes cost-ineffective in one further study following price year adjustment to 2016. Conclusions: Study findings show ITDD as not cost-effective only in extremely conservative scenarios. There is limited evidence on the effectiveness of ITDD in non-cancer pain; however, the available economic evidence controverts arguments to refute the treatment on economic grounds

    Generalized Wasserstein distance and its application to transport equations with source

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    In this article, we generalize the Wasserstein distance to measures with different masses. We study the properties of such distance. In particular, we show that it metrizes weak convergence for tight sequences. We use this generalized Wasserstein distance to study a transport equation with source, in which both the vector field and the source depend on the measure itself. We prove existence and uniqueness of the solution to the Cauchy problem when the vector field and the source are Lipschitzian with respect to the generalized Wasserstein distance

    Initial/boundary-value problems of tumor growth within a host tissue

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    This paper concerns multiphase models of tumor growth in interaction with a surrounding tissue, taking into account also the interplay with diffusible nutrients feeding the cells. Models specialize in nonlinear systems of possibly degenerate parabolic equations, which include phenomenological terms related to specific cell functions. The paper discusses general modeling guidelines for such terms, as well as for initial and boundary conditions, aiming at both biological consistency and mathematical robustness of the resulting problems. Particularly, it addresses some qualitative properties such as a priori nonnegativity, boundedness, and uniqueness of the solutions. Existence of the solutions is studied in the one-dimensional time-independent case.Comment: 30 pages, 5 figure

    Time-evolving measures and macroscopic modeling of pedestrian flow

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    This paper deals with the early results of a new model of pedestrian flow, conceived within a measure-theoretical framework. The modeling approach consists in a discrete-time Eulerian macroscopic representation of the system via a family of measures which, pushed forward by some motion mappings, provide an estimate of the space occupancy by pedestrians at successive time steps. From the modeling point of view, this setting is particularly suitable to treat nonlocal interactions among pedestrians, obstacles, and wall boundary conditions. In addition, analysis and numerical approximation of the resulting mathematical structures, which is the main target of this work, follow more easily and straightforwardly than in case of standard hyperbolic conservation laws, also used in the specialized literature by some Authors to address analogous problems.Comment: 27 pages, 6 figures -- Accepted for publication in Arch. Ration. Mech. Anal., 201

    Métodos para a climatização de bananas ‘prata-anã’ produzidas na Amazônia Setentrional brasileira.

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    O objetivo, neste trabalho, foi avaliar o uso da climatização para a uniformização de bananas 'Prata-Anã' produzidas em Boa Vista-RR. Após colhidos, os frutos foram selecionados no formato de buquês, sanitizados, climatizados por abafamento com lona plástica ou por imersão em solução de Ethrel®, embalados com filme de polietileno de baixa densidade e armazenados por quatro períodos de tempo (0; 10;20 e 30 dias) a 12 ± 1 ºC e 93 ± 2% de UR. Após cada período de armazenamento refrigerado (AR) os frutos foram submetidos ao armazenamento em condições ambiente (22 ± 1 ºC e 75 ± 3% UR), retirados das embalagens plásticas e sendo analisados após 1; 2; 3 e 4 dias. As seguintes análises foram realizadas: perda de massa fresca, coloração da casca, produção de etileno e CO2, atividade das enzimas pectinametilesterase e poligalacturonase, acidez titulável (AT), pectina total e solúvel, amido e sólidos solúveis (SS). Não houve diferenças significativas entre os métodos de climatização, porém verificou-se que, quanto maior o período de AR e de condicionamento, menor foi o período de conservação das bananas 'Prata-Anã'. Ficou evidenciado, também, que a climatização, independentemente do método utilizado, deve ser realizada em até 20 dias após a colheita, nas condições de AR aqui testadas. Nessas condições, foi possível manter a qualidade sensorial das bananas por até 3 dias após a retirada dos frutos do armazenamento refrigerado
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