Numerical simulation of a coupled cardiovascular drug delivery model

A two dimensional coupled model of drug delivery in the cardiovascular tissue using biodegradable drug eluting stents is developed. The qualitative behaviour of the model is analyzed. Numerical results computed with an Implicit Explicit Finite Element Method show a complete agreement with the expected physical behaviour

The effect of reversible binding sites on drug release from drug eluting stents

A coupled non-Fickian model of a cardiovascular drug delivery system using a biodegradable drug eluting stent is proposed. The reversible reaction between the drug and the arterial tissue binding sites are taken into account. The proposed model accounts for the different nature of the therapeutic compounds used. The numerical results are obtained using an IMEX finite element method in the variational form

The role of stiffness in the proliferation of brain tumors

In this paper we present a mathematical model to describe the evolution of glioma cells taking into account the viscoelastic properties of brain tissue. A theoretical stability analysis gives information to design protocols which efficiency is illustrated by a number of numerical simulations

Ruderal Plants Providing Bees Diversity on Rural Properties

Many  are  the  anthropogenic  drivers  of  pollinator  decline,  but  the  loss  of  suitable  habitats, among other effects caused by agricultural intensification, deserves special attention.  Reduction  in  the  availability  of  floral  resources  negatively  affects  bee communities, compromising bee species composition, foraging behavior, corporal size, and fitness. Our study aims to understand whether the presence of herbaceous plants, acting as foraging sites, next to crops contributes to bee species richness in smallholder rural properties. Bee sampling was performed on smallholder rural properties in the municipality of Guapiara, southern São Paulo state. Individuals who visited the flowers of ruderal plants and crops were collected, using an entomological net, for ten months. A total of 61 bee species were identified, with the highest species richness being sampled in ruderal plant flowers in the three properties studied. Only in one property, ruderal plants hosted a more diverse bee assemblage (Shannon-Weiner and taxonomic diversity indices), but species composition differed from that sampled in crop plants (Jaccard index) in all properties. Thirty-two species were sampled exclusively in ruderal plants, versus 9 only in crops and 20 species in both types of plants. Pollen analysis showed that of the 22 species of bees that were sampled only on flowers of ruderal plants, 9 species carried pollen of tomato and one species of bee carried pollen of kabocha squash. Ruderal plants can provide an alternative food resource for pollinators, enabling these insects to remain in or be attracted to crop areas, where, in addition to visiting such plants, they also visit the cultivated plant flowers. Allowing coexistence between crops and ruderal plants, provided that the issues of plant health are observed, is a simple and low-cost measure for farmers and will provide both economic and environmental benefits

Efficient protocols to control glioma growth

In this paper we consider a mathematical model to describe glioma evolution. The model is established combining the viscoelastic behaviour of the brain tissue with a mass conservation law that takes into account the effect of chemotherapy. For the non Fickian model we establish an upper bound for the tumor mass that leads to a sufficient condition to control tumor growth. Based on the theoretical upper bound, protocol for chemotherapy treatment are proposed. Numerical experiments are included to illustrate the behaviour of the model as well as the efficiency of the presented protocols

Educação integral

Monografia (especialização)—Universidade de Brasília, Instituto de Psicologia, Departamento de Psicologia Escolar e do Desenvolvimento Humano, Programa de Pós-Graduação em Processos de Desenvolvimento Humano e Saúde, 2015.O trabalho tem como objetivo mostrar que educação integral, mesmo estando em construção em nosso município de Ipatinga MG, tem dados suficientes para comprovar sua forma de cooperar no processo de educação plena para a cidadania. Suas ações contemplam os alunos do ensino regular e alunos com necessidades educacionais especiais. Participaram desta pesquisa a escola pública a da rede municipal e a Associação de Pais e Amigos dos Excepcionais de Ipatinga – APAE, Associação Recreativa e Cultural de Ipatinga – USIPA e o Centro de Atendimento Multidisciplinar - CENAM que ofertam atividades no contraturno para alunos que interessam pela educação integral. O desenvolvimento do trabalho se deu no estudo de um aluno que é deficiente visual e participa ativamente da educação integral. Para análise dos dados, desenvolvemos entrevistas com professores, família e o aluno objeto da pesquisa. O resultado mostrou que as atividades auxiliaram o aluno até mesmo em competições em torneios com seus pares em Ipatinga. Por fim, observamos que apesar das dificuldades enfrentadas pelas escolas, as atividades propostas no contraturno têm contribuído para que a educação integral de fato aconteça

A mathematical model of controlled drug release in a completely detached vitreous

A model represented by four coupled systems of partial differential equations describing the transport of drug in the posterior segment of the eye is presented. The case of drug release to the retina through an aging eye and where a vitreous chamber detachment has already occurred is analyzed. Numerical simulations lead to a better understanding of in vitro results and suggest new research paths

A mathematical model for controlled drug delivery in swelling polymers

We propose a one-dimensional model to describe the sorption of a solvent by a polymeric membrane, followed by polymer swelling and drug release. We assume that the solvent diffuses into the membrane and induces a stress driven diffusion, that causes a non-Fickian mass flux. We assume that the drug is present in two states (dissolved and undissolved) and that its transport occurs by Fickian diffusion and non-linear dissolution. Polymer swelling is tracked with a volume conservation equation. The system of partial differential equations that define the model is numerically solved. A qualitative analysis of the dependence of the solutions on the parameters of the model shows a complete agreement with the expected physical behavior

Dissolution and bulk erosion in viscoelastic materials: numerical study

A mathematical model to simulate drug delivery from a vicoelastic erodible matrix is presented in this paper. The drug is initially distributed in the matrix which is in contact with water. The entrance of water in the material changes the molecular weight and bulk erosion can be developed depending on how fast is this entrance and how fast degradation occurs. The viscoelastic properties of the matrix also change in the presence of water as the molecular weight changes. The model is represented by a system of quasi linear partial differential equations that take into account different phenomena: the uptake of water, the decreasing of the molecular weight, the viscolestic behaviour, the dissolution of the solid drug and the delivery of the dissolved drug. Numerical simulations illustrating the behaviour of the model are included

Juvenile hormone downregulates vitellogenin production in Ectatomma tuberculatum (Hymenoptera: Formicidae) sterile workers

In the ant Ectatomma tuberculatum (Olivier 1792), workers have active ovaries and lay trophic eggs that are eaten by the queen and larvae. Vitellogenins are the main proteins found in the eggs of insects and are the source of nutrients for the embryo in the fertilized eggs and for adults in the trophic eggs. In social insects, vitellogenin titres vary between castes and affect reproductive social status, nursing, foraging, longevity, somatic maintenance, and immunity. In most insects, vitellogenin synthesis is mainly regulated by juvenile hormone. However, in non-reproductive worker ants, this relationship is poorly characterized. This study determined the effects of juvenile hormone on vitellogenin synthesis in non-reproductive E. tuberculatum workers. Juvenile hormone was topically applied onto workers, and the effect on vitellogenin synthesis in the fat body and vitellogenin titres in the haemolymph were analysed by ELISA and qPCR. Juvenile hormone downregulated protein synthesis and reduced vitellogenin titres in the haemolymph, suggesting that in workers of E. tuberculatum, juvenile hormone loses its gonadotrophic function