Matlab algorithm to simulate the dynamic behavior of an NiTi alloy through Ansys® APDL models

In recent years, technological advances related with the so-called intelligent materials have been exploited for problem solving in many engineering fields. In this regard, shape memory alloys (SMA) seem suitable for medical and engineering applications and many others. These alloys have the ability to return the original form after an apparently plastic deformation by applying heat and the also ability to perform phase changes with voltage variations under a specific temperature. These properties allow the development of a hysteretic loop with energy dissipation, which can be used as a damping element in a vibratory system. In this paper, a MATLAB® algorithm was developed to create an interface with the Ansys® APDL™ software that simulate the dynamic behavior of a SMA. The software is capable to obtain the cyclical behavior of a vibratory mechanical system based on the energy dissipation properties of the SMA. The results shown that the free vibration of a mass-damper (alloy) system presents the energy dissipation related in magnitude with the area of the hysteresis loop until the deformation caused by the motion which does not correspond to a voltage required to initiate the (direct) phase transformation of the material, thus reducing the displacement to a constant level.info:eu-repo/semantics/publishedVersio

Imunoterapia anti-tumoral com células dendríticas

Dendritic cells (DCs) are professional antigen-presenting cells, which display an extraordinary capacity to induce and regulate T-cell responses. Because of their immunoregulatory capacities and because very small numbers of activated DCs are highly efficient in generating immune responses against antigens, DCs have been extensively used in clinical trials in order to elicit or amplify immune responses against cancer. While clinical trials provide evidence that dendritic cells vaccines are safe and elicit immunological responses in most patients, few complete tumor remissions have been reported. To improve the clinical efficacy, it is mandatory to design novel and improved strategies that can boost adaptive immunity to cancer helping to overcome regulatory T cells and allowing the breakdown of the immunosuppressive tumor microenvironment. The association of DCs vaccines with conventional chemo- and radiotherapy protocols could enhance DCs activation and antigen cross-presentation, selectively eliminating immunosuppressive cells, thus reverting the immunosuppression state caused by cancer, suggesting that relevant chemoimmunotherapy associa- tions could fully exploit DC capacity to trigger anticancer responses. As células dendríticas (DCs) são células apresentadoras de antigénio dotadas de uma extraordinária capacidade de estimular e regular a resposta dos linfócitos T. Devido à sua capacidade imunomoduladora e ao reduzido número de DCs ativadas capazes de gerar uma eficiente resposta imunológica, as DCs têm sido muito utilizadas em ensaios clínicos com o intuito de obter ou amplificar uma resposta imune anti-tumoral. Apesar de estudos clínicos evidenciarem que as vacinas de DCs são seguras e induzem uma resposta imunológica na maioria dos doentes, o número de casos com remissões completas do tumor ainda é pequeno. Para aumentar a eficácia clínica é necessário melhorar e criar novas estratégias que incluam a amplificação da imunidade adaptativa anti-tumoral e o bloqueio da proliferação de linfócitos T reguladores e do micro-ambiente imunossupressor. A combinação de vacinas de DCs com os protocolos convencionais de quimio e radioterapia promovem a ativação de DCs, a apresentação cruzada de antigénios e a eliminação seletiva de células imunossupressoras, revertendo o estado de imunossupressão inerente ao tumor. Assim, esta associação de quimioimunoterapia poderá explorar positivamente a capacidade das DCs na obtenção de uma resposta imunológica mais eficaz.

COMPARISON OF THE NUMERICAL SOLUTION OBTAINED BY DIFFERENT CONSTITUTIVE EQUATIONS FOR SHAPE MEMORY ALLOYS

A utilização de materiais inteligentes vêm se tornando essencial para o aperfeiçoamento de aplicações existentes e o desenvolvimento de novas tecnologias. As ligas com memória de forma fazem parte desta classe de materiais, onde as suas características ímpares possibilitam a aplicação como por exemplo: amortecedores, sensores e atuadores. Tendo como objetivo a aplicação destas ligas, será necessário a possibilidade de simular fielmente o comportamento destas, de forma a diminuir custos relacionados com produção de protótipos e o respectivo tempo necessário para produzi-los. O presente trabalho vem comparar as soluções apresentada por dois modelos constitutivos para a mesma liga de Níquel-Titânio, utilizando um algoritmo implementado em Matlab® e o software comercial Ansys® Workbench™. Os resultados apresentam as diferenças quantitativas nos modelos e a respectiva análise mostra os fenômenos que foram levados em conta durante a simulação. Pelo que são necessários ensaios experimentais para a validação dos fenômenos mencionados, calibração dos modelos e comparação para assim identificar o modelo mais representativo na representação do comportamento real da liga.The use of smart materials has become essential for the improvement of existing applications and the development of new technologies. Shape Memory Alloys (SMA) are part of this class of materials, where their unique characteristics allow their application as shock absorbers, sensors and actuators, for example. To apply these alloys, it is necessary simulate reliably their behavior, in order to reduce costs related to the prototype production and time to build them. The present research seeks the comparison between two solutions by different constitutive models for the same Nickel-Titanium alloy. One is using an algorithm implemented in Matlab® and the other with the result available in the literature obtained by commercial software Ansys® Workbench™. The results show the quantitative differences in the models and the phenomena that were taken into account during the simulation. Therefore, experimental tests are required for the validation of the mentioned phenomena, calibration and comparison of the models to identify the most representative model in the representation of the actual behavior of the alloy.info:eu-repo/semantics/publishedVersio

Estudo numérico e experimental de uma liga com memória de forma

O trabalho desenvolvido no âmbito do Instituto Politécnico de Bragança engloba a caracterização do comportamento superelástico de uma liga com memória de forma (LMF) tendo maioritariamente em sua composição Níquel e Titânio. Através de estudos experimentais e calibração de modelos numéricos pretendemos simular o comportamento ímpar das ligas, com o intuito de possibilitar o desenvolvimento de dispositivos capazes de atenuar vibrações indesejadas de altas amplitudes, como em fenômenos de flutter ou sismos.info:eu-repo/semantics/publishedVersio

Motivational Approach by phone for family member of drug user: A case study

A entrevista motivacional, intervenção colaborativa que estimula as razões à mudança, pode ser utilizada para ajudar os familiares de usuários de drogas a conduzir transformações na sua interação com o usuário. Os familiares podem desenvolver estratégias mal-adaptativas para manejarem esse problema, conhecido como codependência. Assim, os familiares necessitam receber intervenção, pois podem adoecer diante dos conflitos decorrentes dessa interação. Objetivou-se apresentar um modelo de intervenção breve motivacional por telefone para familiar de usuário. Realizou-se um estudo de caso em um serviço de telemedicina. Os instrumentos utilizados foram: protocolo de atendimento ao familiar, escalas Contemplation Ladder e Holyoake Codependency Index. Betânia, 46 anos, ligou para buscar ajuda para o seu marido usuário de álcool e crack. Após 6 meses, Betânia conseguiu perceber suas necessidades pessoais e as consequências de sua mudança na dinâmica da dependência química. A esposa do usuário reduziu a codependência e modificou comportamentos permissivos. Os serviços de telemedicina e as intervenções breves motivacionais podem promover mudanças comportamentais em familiares que necessitam de atenção e cuidados de saúde de uma forma acessível e abrangente.Palavras-chave: codependência, entrevista motivacional, telefone.Motivational interviewing, a collaborative intervention that stimulates the reasons to change, can be used to help family members of drug users to drive transformation in their interaction with the user. Families of drug users may develop maladaptive strategies for managing this problem, which is known as codependency. Thus, family members need to receive intervention, as they may get sick due to the conflicts arising from this interaction. The goal was to present a model of brief motivational intervention by telephone to the user’s family. We conducted a case study of a telemedicine service. The instruments used were: family attendance protocol, Contemplation Ladder and Holyoake Codependency Index. Bethany, 46 years, called to get help for her husband, an alcohol and crack user. After 6 months, Bethany was able to realize her personal needs and the consequences of her change in the dynamics of addiction. The user’s wife reduced codependency and modified permissive behavior. Telemedicine services and brief motivational interventions can promote behavioral changes in families that need attention and care in an accessible and comprehensive way.Key words: codependency, motivational interviewing, telephone

The COVID-19 pandemic, emergency aid and social work in Brazil.

This essay reflects on the implementation of federal government emergency aid in Brazil in the context of the COVID-19 pandemic, highlighting elements from the work of Social Workers in the context of growing demand for the supply of material provisions. Economic and social conditions in Brazil have particularities that impact the operationalisation of this benefit, which is aimed at the poor, that add complexity and impose limits. When considering the structural limits set, this context imposes challenges on the work of Social Workers. The need to reconnect and enhance the struggle for social rights is emphasised through the different strategies of the working class

Structural and doping effects in the half-metallic double perovskite A2A_2CrWO6_6

he structural, transport, magnetic and optical properties of the double perovskite $A_2$CrWO$_6$ with $A=\text{Sr, Ba, Ca}$ have been studied. By varying the alkaline earth ion on the $A$ site, the influence of steric effects on the Curie temperature $T_C$ and the saturation magnetization has been determined. A maximum $T_C=458$ K was found for Sr$_2$CrWO$_6$ having an almost undistorted perovskite structure with a tolerance factor $f\simeq 1$. For Ca$_2$CrWO$_6$ and Ba$_2$CrWO$_6$ structural changes result in a strong reduction of $T_C$. Our study strongly suggests that for the double perovskites in general an optimum $T_C$ is achieved only for $f \simeq 1$, that is, for an undistorted perovskite structure. Electron doping in Sr$_2$CrWO$_6$ by a partial substitution of Sr$^{2+}$ by La$^{3+}$ was found to reduce both $T_C$ and the saturation magnetization $M_s$. The reduction of $M_s$ could be attributed both to band structure effects and the Cr/W antisites induced by doping. Band structure calculations for Sr$_2$CrWO$_6$ predict an energy gap in the spin-up band, but a finite density of states for the spin-down band. The predictions of the band structure calculation are consistent with our optical measurements. Our experimental results support the presence of a kinetic energy driven mechanism in $A_2$CrWO$_6$, where ferromagnetism is stabilized by a hybridization of states of the nonmagnetic W-site positioned in between the high spin Cr-sites.Comment: 14 pages, 10 figure

Effects of accelerated versus standard care surgery on the risk of acute kidney injury in patients with a hip fracture : A substudy protocol of the hip fracture Accelerated surgical TreaTment and Care tracK (HIP ATTACK) international randomised controlled trial

Introduction Inflammation, dehydration, hypotension and bleeding may all contribute to the development of acute kidney injury (AKI). Accelerated surgery after a hip fracture can decrease the exposure time to such contributors and may reduce the risk of AKI. Methods and analysis Hip fracture Accelerated surgical TreaTment And Care tracK (HIP ATTACK) is a multicentre, international, parallel-group randomised controlled trial (RCT). Patients who suffer a hip fracture are randomly allocated to either accelerated medical assessment and surgical repair with a goal of surgery within 6 hours of diagnosis or standard care where a repair typically occurs 24 to 48 hours after diagnosis. The primary outcome of this substudy is the development of AKI within 7 days of randomisation. We anticipate at least 1998 patients will participate in this substudy. Ethics and dissemination We obtained ethics approval for additional serum creatinine recordings in consecutive patients enrolled at 70 participating centres. All patients provide consent before randomisation. We anticipate reporting substudy results by 2021. Trial registration number NCT02027896; Pre-results

Development and evaluation of an emulsion containing lycopene for combating acceleration of skin aging

Licopeno é um carotenóide com potente atividade antioxidante encontrado em grande quantidade no tomate e usado no combate a diversas doenças como doenças cardiovasculares e diferentes tipos de cânceres, incluindo o câncer de próstata. O objetivo desse trabalho foi desenvolver uma emulsão contendo extrato de licopeno obtido do tomate salada e avaliar a citotoxicidade do extrato, a estabilidade, o comportamento reológico, atividade antioxidante e permeação do fitocosmético. O cosmético foi desenvolvido utilizando fase oleosa contendo derivados de Karité e submetido à avaliação da estabilidade físico-química, espalhabilidade, análise térmica, comportamento reológico, qualidade microbiológica, citotoxicidade, atividade antioxidante e testes de permeação e retenção cutânea. Os resultados demonstraram que o fitocosmético é estável, apresenta comportamento reológico desejável para uma formulação tópica e é um produto promissor para ser utilizado no combate à aceleração do envelhecimento cutâneo.Lycopene, a carotenoid and potent antioxidant is found in large quantities in tomatoes. Lycopene combats diseases, such as cardiovascular disease and different types of cancer, including prostate cancer. However, its topical use in emulsion form for the combat of skin aging is under-explored. The aim of the present study was to develop an emulsion containing lycopene extracted from salad tomatoes and evaluate its cytotoxicity, stability, rheological behavior, antioxidant activity and phytocosmetic permeation. The developed cosmetic comprised an oil phase made up of shea derivatives and was evaluated in terms of its physiochemical stability, spreadability, thermal analysis, rheological behavior, microbiological quality, cytotoxicity, antioxidant activity, cutaneous permeation and retention. The results demonstrate that this phytocosmetic is stable, exhibits satisfactory rheological behavior for a topical formula and is a promising product for combating skin aging