Competition controls the rate of transition between the peripheral pools of CD4+CD25− and CD4+CD25+ T cells

Recent reports have hinted that it is possible to regenerate CD4+CD25+ regulatory T cells (Treg) from CD4+CD25− cells, a phenomenon termed conversion. We evaluated the relative contribution of this process to the Treg pool by transferring purified populations of CD4+ T cells into T cell-deficient mice. We report that conversion of CD25− cells into the CD4+CD25+Treg pool is minor if other bona fide CD25+ Tregs are present. Moreover, in the same hosts, the loss of CD25 expression by a population of Tregs also decreases in the presence of co-injected CD4+CD25− cells. Thus, the rate of exchange between CD25− and CD25+ T-cell populations is determined by the presence or absence of T-cell competitors. Our results attest for the role of competition in the contribution of different T-cell subsets for the regeneration of the peripheral CD4+ T-cell pool during lymphopeni

Caracterização mecânica de um solo fino

A tese que se apresenta, expõe o estudo de aplicabilidade do ensaio edométrico, nomeadamente com recurso à instrumentação de três edómetros, a uma areia siltosa, existente na cidade de Bragança, sendo que objetiva a aplicabilidade do ensaio aos solos de granulometria mais fina da região, com a ressalva de que a curva granulométrica destes se afasta de forma substancial das curvas granulométricas dos solos que por norma são alvo do ensaio edométrico. Objetiva assim o estudo efetuado, a aplicabilidade do ensaio aos solos mais finos oriundos de uma região com predominância de maciço residual granítico. Dado que o solo ensaiado apresenta características pertencentes aos dois tipos de solo mais comuns no âmbito da geotecnia, a presente tese, foca as características fundamentais destes dois grupos, dando especial enfoque aos solos finos. Estando o processo de consolidação, associado à existência de estratos compressíveis no solo de fundação, que muitas vezes dão origem a assentamentos mais ou menos pronunciados, cuja velocidade e magnitude dependem dos parâmetros físicos e mecânicos do solo, e do valor da tensão que neles se induz, a presente tese, para além da determinação dos parâmetros referidos, enfoca, no domínio da mecânica clássica, um estudo acerca da indução de tensões, provenientes de diferentes tipos de fundações superficiais. Em termos de resumo, o estudo efetuado apresenta ainda um exemplo, onde se estima o valor da magnitude de assentamento, em um maciço constituído por dois estratos compressíveis, materializados nos dois solos ensaiados, solicitados pelo valor da tensão induzida por duas sapatas de labo !, afastadas de !, e desenvolvimento infinito ", na consideração de estrato confinado, onde se poderá observar a delicadeza com que estes maciços deverão ser tratados, nomeadamente o baixo valor da tensão a que deverão ser solicitados, para que neles não ocorram assentamentos excessivos, sendo que dos resultados de laboratório obtidos, se permite aferir a aplicabilidade de ensaio aos solos que evidenciem plasticidade, nomeadamente os relativos à região envolvente.This thesis exposes the applicability study of the oedometer test, in particular, with the use of three instrumented oedometers, to an existing silty sand soil, from the city of Braganza, aiming the applicability of the test to the finest soils in the region, considering that the granulometric curve of these soils are substantially different from the granulometric curves of the soils that are usually tested. According to this, the study aim the applicability of the test to the fine grain soils from a region with a predominance of granitic residual soils. Due to the tested soil characteristics belong to the two most common types of soil from geotechnics point of view, this study focuses the fundamental characteristics of these two groups of soils, with a special focus on fine grains soils. Since the consolidation process, associated to the existence of compressible strata, which often give rise to more or less pronounced settlements, whose speed and magnitude depend on the physical and mechanical parameters of the soil, and the magnitude, of the induced stress, the present thesis, in addition to the determination of the referred parameters, focuses, in the field of classical mechanics, a study about the induced stress, coming from different types of surface foundations. In resume terms, the present study also gives an example for the estimate value off the settlement magnitude, on two compressible strata, materialized in the two types of soil tested, with the induced stress from two foundations with ! side length, distanced from ! length, both foundations with infinite side length ", in confined stratum situation, evidencing the delicacy associated to the soil strata, namely the low induced stress value to which they should be requested to avoid major settlements. In addition to this, the results obtained from the laboratory, allows to say, that it´s possible to apply the oedometer test to the soils from the surrounding region that evidence some plasticity

Applicability study os the oedometer test to a silty sand

This paper exposes the applicability study of the oedometer test to an existing silty sand soil, from the city of Braganza, with the purpose to verify the applicability of this test to soils with fines in his composition, in a region with predominance of granite residual soils, considering that the granulometric curve of these soils are substantially different from the granulometric curves of the soils that are usually tested. For this, two types of soils were collected, namely intact samples of a silty sand, and a disturbed soil sample whose grains size distribution curve built into laboratory corresponds to a high plasticity silt. Due to the greater predominance of fines in the high plasticity silt, the mechanical behaviour of this soil, more conditioned by forces of an electrochemical nature, serves as a comparative term to the mechanical behaviour of the undisturbed samples of the silty sand, with a behaviour less dependent on these forces, thus allowing to show applicability of the test to soils with lower percentage of fines, with a more pronounced gravitational behaviour and, therefore, more atypical to the oedometer test. From the results obtained for silty sand, a high value of the immediate settlement was verified after each applied load cycle. Thus this observation, the beginning of the consolidation process demands high accurate recording of the settlement that clearly identify the time that primary consolidation begins. In this way, the implementation of the data acquisition system, allowing the correct reading of the consolidation beginning, minimizing human errors, expands the spectrum of soils existing in the region that can be study by the consolidation problematics point of view.info:eu-repo/semantics/publishedVersio

New topology of a hybrid, three-phase, four-wire shunt active power filter

With a view to reducing harmonic content in electrical power systems, and, consequently, improving power quality level, filters and other harmonic compensation devices are widely used. In the category of filters, they can be distinguished into two classes that are related to the operating mode, active or passive, both widely known and applied in electrical power grids and in the most diverse industry sectors. In this sense, taking into account the use of compensating devices in four-wire electrical systems feeding single-phase, non-linear loads, this paper presents a new hybrid arrangement of harmonic compensation that incorporates both active and passive filtering, which performs all functions concerning the harmonic compensation of a four-leg shunt active power filter. In this hybrid arrangement, the harmonic filtering of positive and negative sequence components is performed by a three-leg shunt active power filter, while the filtering of zero-sequence harmonics is attributed to the electromagnetic zero-sequence suppressor. The results, which confirm the effectiveness of the proposed hybrid arrangement, are proven through simulations and experimental tests in different operating scenarios, revealing a substantial improvement in the system’s power factor, as well as a reduction in harmonic distortions.This research was funded by FCT—Fundação para a Ciência e Tecnologia grant number UIDB/00319/2020

Modeling, design, and experimental test of a zero‐sequence current electromagnetic suppressor

This paper presents the experimental investigation of an electromagnetic suppressor to minimize the circulation of zero‐sequence currents in three‐phase four‐wire distribution systems. The proposed zero‐sequence current electro- magnetic suppressor (ZSS) integrates two distinct electromagnetic devices, namely a zero‐sequence filter (ZSF) and a zero‐ sequence blocker (ZSB), connected in parallel and in series between the source and the load, respectively. In this paper are presented the theoretical modeling and analysis of each device, the mathematical concepts of harmonic compensation, and the procedures for the design and determination of the constructive details. The experimental results of the combined operation of the devices that integrate the ZSS demonstrate the feasibility of the proposed arrangement, by minimizing the flow of the zero‐sequence harmonic currents in the source side, enabling a significant reduction of the current in the neutral conductor, and also by improving the system power factor.This work has been supported by CNPq ‐ National Council for Scientific and Technological Development, by CAPES ‐ Coordinationfor the Improvement of Higher Education Personnel through the PDSE ‐ Doctoral Program Sandwich Abroad 7427‐12‐3, and by FCT ‐ Foundation for Science and Technology within the Project Scope: UID/CEC/00319/2019 and FCT within project PTDC/EEI‐EEE/28813/2017

PARTICIPAÇÃO NO PROCESSO DECISÓRIO DO APL DE VESTUÁRIO DE MURIAÉ-MG

A governança permite superar os desafios dos Arranjos Produtivos Locais (APLs) quanto às formas de cooperação e coordenação de ações conjuntas. A participação dos atores no processo decisório do APL é um elemento importante para caracterizar a governança, pois algumas investigações sugerem que o desenvolvimento do APL tem relação direta com essa participação. Nesse contexto, o objetivo deste estudo foi compreender a participação dos atores no processo decisório do APL de Vestuário de Muriaé-MG. Foi feita uma pesquisa qualitativa de caráter descritivo. Os dados primários foram coletados por meio de entrevistas semiestruturadas com 19 atores do APL, em julho de 2014, e analisados pela técnica de análise de conteúdo, com suporte do software NVivo®. Com a pesquisa constatou-se que os representantes das empresas não participam do processo decisório. Ao contrário do que ocorre com os representantes das entidades, dentre os quais se percebeu um maior envolvimento no processo decisório do APL. Conclui-se que no APL de Vestuário de Muriaé-MG o processo decisório é centralizado nas entidades, o que caracteriza a participação no processo decisório como incipiente. Resultado que faz surgir o interesse em investigar outros elementos, como os mecanismos que podem ser indicados, sugeridos ou criados para que a participação dos atores ocorra de forma efetiva

Retrosternal Goiter – Cancer Incidence

O bócio retroesternal é uma afecção rara da glândula tireóide, que acomete principalmente mulheres acima de 60 anos, caracterizada por tireóide aumentada de tamanho, peso e volume, que invade a cavidade torácica total ou parcialmente. A não realização do ato cirúrgico tem sido preconizada em alguns casos como forma alternativa de melhoria da qualidade de vida, sobretudo em pacientes idosos assintomáticos. Todavia, existe uma incidência de câncer nos bócios retroesternais, associado a um índice maior de complicações, que justifica a abordagem cirúrgica precoce, principalmente em pacientes jovens, mesmo que assintomáticos. Este trabalho resulta de um relato de caso e revisão de literatura, sobre bócio retroesternal e incidência de câncer em uma paciente de 62 anos, submetida a tireoidectomia total, com achados histopatológicos de pós operatório, de carcinoma papilífero, carcinoma folicular e adenoma folicular. Esses achados nos alerta para a possibilidade de incidência de câncer nesses pacientes, devendo ser aventado o tratamento cirúrgico precoceThe retrosternal goiter is a rare thyroid gland disease, which mainly affects women over 60 years, characterized by increased thyroid size, weight and volume, which invades the thoracic cavity. Failure to perform the surgery has been recommended in some cases as an alternative way of improving the quality of life, especially in asymptomatic elderly patients. However, there is an incidence of cancer in retrosternal goiters associated with a higher rate of complications, justified the early surgical approach, especially in young patients, even if asymptomatic. This work results from a case report and literature review on retrosternal goiter and cancer incidence in a 62-year-old patient submitted total thyroidectomy with histopathologic findings after surgery, papillary carcinoma, follicular carcinoma and follicular adenoma. These findings alerts us to the possibility of cancer incidence in these patients, recommending in such cases, early surgical treatmen

Análise comparativa entre ecofuncional por pediatra e ecocardiografia compreensiva por cardiologista em unidade de terapia intensiva pediátrica e neonatal

Introduction: Bedside ultrasound performed by a non-imaging specialist has proven to be a useful tool in the diagnostic evaluation and performance of invasive procedures. Several clinical situations favor manifestations of hemodynamic instability, especially in intensive care units. Nowadays, several pediatric units have used functional echocardiography (fECHO) and, often, before the examination by echocardiography performed by a cardiologista (cECHO). Objective: Compare the accuracy of echocardiography performed by a pediatrician (fECHO) and a cardiologist (cECHO) on neonatal and pediatric patients in an intensive care unit. Material and Methods: Retrospective analysis of the medical records of pediatric patients from zero days to 14 years, admitted to the intensive care unit, with a clinical indication for evaluation by comprehensive echocardiography of anatomical cardiac alterations were also evaluated through ecofunctional by a pediatrician. Results: Eight nine patients were admitted from zero days to 14 years, 55 of whom were male, and 34 were female. The respective sensitivity and specificity of fECHO and cECHO were 80% and 96.2% for the persistence of the ductus arteriosus; 88.4% and 98.4% for congenital acyanotic heart disease; 77.7% and 98.7% for congenital cyanotic heart disease; 83.3% and 98.8% for ventricular hypertrophy; 100% and 100% for pericardial effusion; 76.2% and 96.2% for persistent neonatal pulmonary hypertension. Conclusions: The results demonstrate a good accuracy of the pediatrician performing fECHO compared with a examination performed by the cardiologist, which does not reduce the importance and obligation of expert assessment. The incorporation of fECHO in the routine pediatric evaluation allows for the expansion and improvement of the pediatrician's physical examination.Introdução: A ultrassonografia à beira do leito realizada por não especialista em imagem tem mostrado ser uma ferramenta útil na avaliação diagnóstica e realização de procedimentos invasivos. Diversas situações clínicas favorecem manifestações de instabilidade hemodinâmica, principalmente, nas unidades de terapia intensiva. Neste sentido, unidades pediátricas têm utilizado ecocardiografia funcional, muitas vezes, antes do exame realizado por um ecocardiografista. Objetivo: Avaliar a acurácia da ecocardiografia realizada por pediatra comparativamente à realizada por ecocardiografista em pacientes de uma unidade neonatal e pediátrica de tratamento intensivo. Material e Métodos: Análise retrospectiva dos prontuários de pacientes pediátricos de zero dia a 14 anos, internados na unidade de terapia intensiva, com indicação clínica para avaliação da existência de alterações anatômicas por ecocardiografia compreensiva e que também foram avaliados através da ecocardiografia funcional por pediatra. Resultados: Um total de 89 casos foram analisados com admissão variando de zero dia a 14 anos, sendo 55 do sexo masculino e 34 do sexo feminino. A sensibilidade e especificidade, respectivamente, da ecocardiografia funcional pelo pediatra comparado à ecocardiografia compreensiva feita pelo cardiologista relativamente às alterações encontradas foram: 80% e 96,2% para persistência do canal arterial; 88,4% e 98,4% para cardiopatia congênita acianótica; 77,7% e 98,7% para cardiopatia congênita cianótica e/ou críticas; 83,3% e 98,8% para miocardiopatia hipertrófica; 100% e 100% para derrame pericárdico; e 76,2% e 96,2% para hipertensão pulmonar persistente neonatal. Conclusões: Os resultados demonstram boa acurácia do pediatra realizando a ecocardiografia funcional quando comparado com exame realizado pelo cardiologista (ecocardiografia compreensiva), o que não reduz a importância e obrigatoriedade da análise do especialista. A incorporação da ecocardiografia funcional na avaliação rotineira pediátrica permite expandir e melhorar o exame físico pelo pediatra

Cell-to-Cell Interactions and Signals Involved in the Reconstitution of Peripheral CD8+ TCM and TEM Cell Pools

We here describe novel aspects of CD8+ and CD4+ T cell subset interactions that may be clinically relevant and provide new tools for regulating the reconstitution of the peripheral CD8+ T cell pools in immune-deficient states. We show that the reconstitution capacity of transferred isolated naïve CD8+ T cells and their differentiation of effector functions is limited, but both dramatically increase upon the co-transfer of CD4+ T cells. This helper effect is complex and determined by multiple factors. It was directly correlated to the number of helper cells, required the continuous presence of the CD4+ T cells, dependent on host antigen-presenting cells (APCs) expressing CD40 and on the formation of CD4/CD8/APC cell clusters. By comparing the recovery of (CD44+CD62Lhigh) TCM and (CD44+CD62Llow) TEM CD8+ T cells, we found that the accumulation of TCM and TEM subsets is differentially regulated. TCM-cell accumulation depended mainly on type I interferons, interleukin (IL)-6, and IL-15, but was independent of CD4+ T-cell help. In contrast, TEM-cell expansion was mainly determined by CD4+ T-cell help and dependent on the expression of IL-2Rβ by CD8 cells, on IL-2 produced by CD4+ T-cells, on IL-15 and to a minor extent on IL-6