Hybrid integral transforms analysis of the bioheat equation with variable properties

Pennes’ equation is the most frequently employed model to describe heat transfer processes within living tissues, with numerous applications in clinical diagnostics and thermal treatments. A number of analytical solutions were provided in the literature that represent the temperature distribution across tissue structures, but considering simplifying assumptions such as uniform and linear thermophysical properties and blood perfusion rates. The present work thus advances such analysis path by considering a heterogeneous medium formulation that allows for spatially variable parameters across the tissue thickness. Besides, the eventual variation of blood perfusion rates with temperature is also accounted for in the proposed model. The Generalized Integral Transform Technique (GITT) is employed to yield a hybrid numerical–analytical solution of the bioheat model in heterogeneous media, which reduces to the exact solution obtained via the Classical Integral Transform Method for a linear formulation with uniform coefficients. The open source UNIT code (“Unified Integral Transforms”) is utilized to obtain numerical results for a set of typical values of the governing parameters, in order to illustrate the convergence behavior of the proposed eigenfunction expansions and inspect the importance of accounting for spatially variable properties in predicting the thermal response of living tissues to external stimulus.Indisponível

O processo de produção de uma injustiça ambiental e seus impactos: o caso do CTR Rio em Seropédica

O artigo tem como objetivo contar um pouco da história da implementação do aterro sanitário de Seropédica (CTR Rio) para receber todo o lixo do município do Rio de Janeiro, dentre outros municípios, ressaltando a frágil relação intermetrópole, em que a cidade central reforça o papel de zona de sacrifício da cidade periférica e, ainda, os reais impactos socioambientais, positivos e negativos, do funcionamento da unidade. Para tal, traz alguns referenciais teóricos, destacando o processo de metropolização em curso que, à luz da teoria da Justiça Ambiental, demonstra a nova função que Seropédica passa a desenvolver na dinâmica metropolitana.The article aims to tell a short history about the Seropédica landfill (CTR Rio) installation to receive all the waste from the municipality of Rio de Janeiro, among other municipalities, underscoring the fragile inter-metropolis relationship, on what the central city reinforces the role of the peripheral city as a sacrifice zone, and also the real, positive and negative, socioenvironmental impacts of the unit’s operation. It brings some theoretical references, highlighting the ongoing metropolization process that, in the light of the Environmental Justice theory, demonstrates the new function that Seropédica develops in the metropolitan dynamics.L’article vise à raconter un peu l’histoire de la mise en place de la décharge de Seropédica (CTR Rio) pour recevoir toutes les ordures de la municipalité de Rio de Janeiro, entre autres municipalité, en mettant en évidence la fragile relation intermétropole, dans laquelle la ville centrale renforce le rôle de la zone de sacrifice de la ville périphérique et, aussi, les impacts socio-environnementaux réels, positifs et négatifs, du fonctionnement de l’unité. À cette fin, il apporte quelques références théoriques, mettant en évidence le processus de métropolisation en cours qui, à la lumière de la théorie de la Justice Environnementale, démontre la nouvelle fonction que Seropédica commence à développer dans la dynamique métropolitaine.El articulo tiene el objetivo narrar la historia da implantación del relleno sanitario de Seropédica (CTR Rio) para recibir la toda la basura del municipio de Rio de Janeiro y de otros municipios, destacando la frágil relación intra metropolitana, en que la ciudad central refuerza el papel de la ciudad periférica como zona de sacrificio y, también, los reales impactos socioambientales, positivos y negativos, de la operación de la unidad fabril. Para esto, traemos algunas referencias teóricas, destacando el proceso de metropolización en curso que, a la luz de la teoría de la justicia ambiental, apunta la nueva función que Seropédica pasa a desarrollar en la dinámica metropolitana

Malignant melanoma with liver and spleen metastases: case report

CONTEXT: The diagnosis of primary melanoma is easily confirmed after histological analysis of the lesion, whereas it is rarely diagnosed when the patient even has distant metastases. DESIGN: Case report CASE REPORT: Malignant melanoma is responsible for about 1% of all deaths caused by cancer in the USA and only 3% of all malig-nant skin diseases. Malignant melanoma is a rare disease, although it corresponds to 65% of all deaths caused by skin cancer. The liver and spleen are rarely the first sites of melanoma metastases. This paper reports on the clinical picture of a patient with fatal malignant melanoma and hepatic and spleen metastases. As this was an un-usual presentation, the melanoma diagnosis could only be made after pathological analysis of the skin and hepatic lesions.CONTEXTO: O melanoma maligno é responsável por aproximadamente 1% de todas as mortes causadas por câncer nos EUA e apenas 3% de todas as doenças malignas cutâneas. Embora considerada uma patologia rara, representa 65% de todos os óbitos por câncer de pele. O fígado e o baço raramente são os primeiros sítios de metástases de melanoma. TIPO DE ESTUDO: Relato de caso. RELATO DE CASO: Este artigo relata o quadro de um paciente portador de melanoma maligno evoluindo para óbito com metástases hepática e esplênica. Por ser uma apresentação atípica da doença, o diagnóstico definitivo ocorreu somente após a análise histopatológica das lesões de pele e do fígado.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of PathologyUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Gastroenterology DivisionUNIFESP, EPM, Department of PathologyUNIFESP, EPM, Gastroenterology DivisionSciEL

Recent advances in computational-analytical integral transforms for convection-diffusion problems

An unifying overview of the Generalized Integral Transform Technique (GITT) as a computational-analytical approach for solving convection-diffusion problems is presented. This work is aimed at bringing together some of the most recent developments on both accuracy and convergence improvements on this well-established hybrid numerical-analytical methodology for partial differential equations. Special emphasis is given to novel algorithm implementations, all directly connected to enhancing the eigenfunction expansion basis, such as a single domain reformulation strategy for handling complex geometries, an integral balance scheme in dealing with multiscale problems, the adoption of convective eigenvalue problems in formulations with significant convection effects, and the direct integral transformation of nonlinear convection-diffusion problems based on nonlinear eigenvalue problems. Then, selected examples are presented that illustrate the improvement achieved in each class of extension, in terms of convergence acceleration and accuracy gain, which are related to conjugated heat transfer in complex or multiscale microchannel-substrate geometries, multidimensional Burgers equation model, and diffusive metal extraction through polymeric hollow fiber membranes. Numerical results are reported for each application and, where appropriate, critically compared against the traditional GITT scheme without convergence enhancement schemes and commercial or dedicated purely numerical approaches.Indisponível

Control of Small Spacecraft by Optimal Output Regulation: A Reinforcement Learning Approach

The growing number of noncooperative flying objects has prompted interest in sample-return and space debris removal missions. Current solutions are both costly and largely dependent on specific object identification and capture methods. In this paper, a low-cost modular approach for control of a swarm flight of small satellites in rendezvous and capture missions is proposed by solving the optimal output regulation problem. By integrating the theories of tracking control, adaptive optimal control, and output regulation, the optimal control policy is designed as a feedback-feedforward controller to guarantee the asymptotic tracking of a class of reference input generated by the leader. The estimated state vector of the space object of interest and communication within satellites is assumed to be available. The controller rejects the nonvanishing disturbances injected into the follower satellite while maintaining the closed-loop stability of the overall leader-follower system. The simulation results under the Basilisk-ROS2 framework environment for high-fidelity space applications with accurate spacecraft dynamics, are compared with those from a classical linear quadratic regulator controller, and the results reveal the efficiency and practicality of the proposed method

Wheeled mobility: the perception of parents of children with cerebral palsy

Children with cerebral palsy (CP) often use mobility devices as facilitators of their functionality and independence, and these devices may have a positive impact on their caregivers’ quality of life. Considering a family-centered approach, parents assume a decisive role in different stages of the therapeutic process, guiding several actions of the rehabilitation professionals during the search, development and/or adaptation of equipment that meet the specific needs of customers. The aim of this research was to understand the perceptions of parents of children with CP on the use of the wheelchair in the daily routines of their children. This qualitative study used semi-structured interviews with 16 parents of CP children who were wheelchair users assisted at ‘Associação Mineira de Reabilitação’. Content analysis grounded the categorization of themes that emerged from the interviews. The results expressed in themes such as “The look on the daily routine” and “The look on the equipment” pointed out characteristics related to the benefits of the use of the wheelchair in promoting child participation at home, at school, and in community environments, as well as different features of wheelchairs that facilitate or hamper their use in children’s daily routine