Abstract The present paper evaluated the potential application of the functionally graded material (FGM) concept to develop more durable concrete to carbonation, one of the main degradation mechanisms of reinforced concrete structures. Accelerated carbonation tests with controlled temperature (27 ( 2°C), CO2 concentration (3 ( 0.5%) and humidity (65 ( 5%) were carried out in homogeneous concretes and with functional gradation in which the porosity of the material was varied across the slices. For the manufacture of graded concrete specimens, concretes with water/cement ratios equal to 0.35, 0.45, and 0.55 were produced, with lower porosity (w/c = 0.35) close to the surface of the specimen. The advance of the carbonation front was evaluated after 8, 9, 10, 14, and 24 weeks of accelerated exposure, using the chemical indicator phenolphthalein. The results show that the functionally graded concrete had a carbonation coefficient (K) slightly higher than that of the concrete with a w/c ratio equal to 0.35 (1.71 and 1.54 mm.week-0.5, respectively) and much lower than concrete with water-cement ratio equal to 0.45 (2.31 mm.week-0.5) and 0.55 (3.78 mm.week-0.5). This demonstrates that functional grading can be an efficient method to increase the durability of concrete elements subject to carbonation.

Resumo O presente artigo avalia o potencial de aplicação do conceito de material com gradação funcional (MGF) ao desenvolvimento de concretos mais duráveis frente à carbonatação, um dos principais mecanismos de degradação das estruturas de concreto armado. Ensaios acelerados de carbonatação com temperatura (27 ( 2 °C), concentração de CO 2 (3 ( 0,5%) e umidade (65 ( 5%) controladas foram realizados em concretos homogêneos e com gradação funcional em que a porosidade do material foi variada ao longo dos corpos de prova. Para a confecção dos corpos de prova de concreto com gradação funcional foram utilizados concretos com relações água/cimento iguais a 0,35, 0,45 e 0,55 de forma que tivéssemos uma redução de porosidade à medida que nos aproximássemos da superfície da peça. O avanço da frente de carbonatação foi avaliado após 8, 9, 10, 14 e 24 semanas de exposição acelerada, empregando-se o indicador químico fenolftaleína. A partir dos resultados obtidos observou-se que os concretos com gradação funcional apresentaram coeficiente de carbonatação (K) ligeiramente superior ao do concreto com relação a/c igual a 0,35 (1,71 e 1,54 mm.semana -0,5 , respectivamente) e bastante inferior aos concretos com relação água cimento iguais a 0,45 (2,31 mm.semana -0,5 ) e 0,55 (3,78 mm.semana -0,5 ), evidenciando que a gradação funcional pode ser um método eficiente para proporcionar o aumento da durabilidade de elementos de concreto sujeitos à carbonatação.

Abstract Sisal (Agave sisalana) is a plant exploited in semi-arid regions of Brazil for fiber production, but the floral scape of sisal (peduncle) is collected and often burned, causing environmental problems, even through irregular disposal. To circumvent this scenario, the objective of this work was to produce reconstituted panels using the sisal arrow and castor-based polyurethane resin. The panels were obtained using 175 g of crushed sisal arrow core with dimensions smaller than 2 mm and adopting 10% castor-based polyurethane resin and The samples were pressed under tension of 2 MPa. The properties of reconstituted panel were evaluated through NBR 14810-1 (ABNT, 2013) and NBR 14810-2 (ABNT, 2018), the physical properties were investigated: moisture, density, thickness swelling and absorption; as well as mechanical properties: MOR, MOE, internal bond and parallel compression. The found results show that the panel is classified as low density (419.8 kg/m³), and with physical and mechanical properties similars to other panels of the same classification in the literature. For average values of MOR and MOE it was found 5.24 MPa and 147.49 MPa, respectively. For internal bonding it was found 0.14 MPa and for parallel compression properties it was found 1.14 MPa.

Resumo O sisal (Agave sisalana) é uma planta explorada nas regiões semiáridas do Brasil para produção de fibras, mas o escapo floral do sisal (flecha) é coletado e frequentemente queimado causando problemas ambientais, até mesmo pelo descarte irregular. Para contornar este cenário, o objetivo deste trabalho foi produzir painéis reconstituídos usando a flecha do sisal e resina poliuretana à base de mamona. Os painéis foram obtidos empregando 175 g do miolo da flecha de sisal triturada com dimensões inferiores a 2 mm e adotando 10% de resina poliuretana à base de mamona e as amostras foram prensadas com tensão de 2 MPa. Avaliou-se no painel reconstituído, através da NBR 14810-1 (ABNT, 2013) e NBR 14810-2 (ABNT, 2018) as propriedades físicas: umidade, densidade, inchamento e absorção; bem como as propriedades mecânicas: MOR, MOE, força de ligação e compressão paralela. Os resultados encontrados mostram que o painel é classificado como de baixa densidade (419,8 kg/m³), e de propriedades físicas e mecânicas semelhantes a outros painéis de mesma classificação da literatura. Para MOR e MOE foram encontrados 5,24 MPa e 147,49 MPa de média, respectivamente. Já os ensaios de tração perpendicular e compressão paralela obtiveram resultados de 0,14 MPa e 1,14 MPa, respectivamente.

Abstract We investigated posts on Twitter using the word “datapovo”, which became popular in the context of the 2022 presidential elections in Brazil. The term refers to content that sought to discredit electoral polls, in contrast to the imagery record of crowds of supporters of candidates. We use concepts of pragmatism and semiotics in order to understand how these signs can stimulate the fixation of beliefs around a possible fragility in the electoral process. We also highlight the manipulation of contemporary technical images, fostering debates on the sign effects of this type of strategy in disinformation processes.

Resumo Investigamos postagens no Twitter com a expressão datapovo, que se popularizou no contexto das eleições presidenciais de 2022 no Brasil. O termo se refere a conteúdos que buscavam questionar as pesquisas eleitorais, em contraste com o registro imagético da multidão de apoiadores dos candidatos. Acionamos conceitos do pragmatismo e da semiótica, a fim de compreender como esses signos podem estimular a fixação de crenças de uma possível fragilidade no processo eleitoral. Levantamos também uma reflexão sobre a manipulação das imagens técnicas contemporâneas, fomentando debates sobre os efeitos sígnicos desse tipo de estratégia nos processos de desinformação.

SUMMARY OBJECTIVE: The objective of this study was to evaluate possible cytogenetic changes in children and adolescents with human immunodeficiency virus on antiretroviral therapy, through the micronucleus test in oral mucosa. METHODS: This was a prospective study consisted of 40 individuals, of whom 21 comprised the human immunodeficiency virus group and 19 comprised the control group. Children and adolescents with human immunodeficiency virus were enrolled. The inclusion criteria were <18 years old and consent in participating in the study. The exclusion criteria were the presence of numerous systemic comorbidities, oral lesions, the habit of smoking, alcohol consumption, and X-rays or CT scans taken within 15 days prior to sample collection. A gentle scraping was performed on the inner portion of the jugal mucosa on both sides. A total of 2,000 cells per slide were analyzed for the determination of mutagenicity parameters as follows: micronuclei, binucleation, and nuclear buds. For measuring cytotoxicity, the following metanuclear changes were evaluated: pyknosis, karyolysis, and karyorrhexis, in a double-blind manner. The repair index was also evaluated in this setting. RESULTS: The human immunodeficiency virus group showed high frequencies of micronuclei (p=0.05), binucleated cells (p=0.001), and nuclear buds (p=0.03). In the cytotoxicity parameters, represented by the cell death phases, there was an increase with statistical difference (p≤0.05) in the karyorrhexis frequency (p=0.05). Additionally, repair index was decreased in the human immunodeficiency virus group. CONCLUSION: These results indicate that human immunodeficiency virus -infected individuals undergoing antiretroviral therapy have cytogenetic changes in oral mucosal cells.

Abstract The aim of this systematic review was to evaluate published papers regarding the micronucleus assay in oral mucosal cells of patients undergoing orthodontic therapy (OT). A search of the scientific literature was made in the PubMed, Scopus, and Web of Science databases for all data published until November, 2021 using the combination of the following keywords: “fixed orthodontic therapy,” “genetic damage”, “DNA damage,” “genotoxicity”, “mutagenicity”, “buccal cells”, “oral mucosa cells,” and “micronucleus assay”. The systematic review was designed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Nine studies were retrieved. Some authors demonstrated that OT induces cytogenetic damage in oral mucosal cells. Out of the nine studies included, two were classified as strong, five as moderate, and two as weak, according to the quality assessment components of the Effective Public Health Practice Project (EPHPP). Meta-analysis data revealed no relationship between mutagenicity in oral cells and OT in different months of treatment. At one month, the SMD = 0.65 and p = 0.08; after three months of OT, the SMD = 1.21 and p = 0.07; and after six months of OT, the SMD = 0.56 and p = 0.11. In the analyzed months of OT, I2 values were >75%, indicating high heterogeneity. In summary, this review was not able to demonstrate that OT induces genetic damage in oral cells. The study is important for the protection of patients undergoing fixed OT, given that mutagenesis participates in the multi-step process of carcinogenesis.

Resumo: O desafio de garantir integridade acadêmica na avaliação a distância tornou-se tema emergente com a remotização do ensino no período de pandemia. Uma abordagem que pode dificultar a cópia de respostas e incentivar o desenvolvimento individual de soluções de questões em instrumentos avaliativos é a individualização de questões. Para tanto, a automação pode ser uma grande aliada, de modo a ser possível gerar enunciados e gabaritos distintos por meio de constantes e variáveis. Este trabalho disserta sobre uma experiência de automação na geração de provas individualizadas no período de ensino emergencial. A abordagem parece ter atenuado, entre os alunos, de cópia de soluções e respostas, ou a obtenção destas na internet ou em livros didáticos. Ainda, a experiência pode ser vista como uma tentativa de solução multifatorial, em um contexto complexo, indicando a viabilidade para o desenvolvimento de um framework capaz de atender também a outros domínios do conhecimento e seus segmentos. Resumo tornouse tornou se pandemia tanto aliada variáveis emergencial atenuado alunos didáticos Ainda multifatorial complexo segmentos

Abstract: During the pandemic period, the challenge of maintaining academic integrity in distance learning has emerged as a key issue. Individualization of questions is an approach that can make it difficult for students to copy answers and can encourage personal development of solutions in evaluation tools. Automation could be a great help in this situation because it makes it possible to create different rubrics and answer keys by using constants and variables. This paper discusses the experience with automated personalized test generation during the period of emergency remote teaching. The strategy appears to have mitigated, among students, the tendency to copy solutions and answers from their classmates, find them online, or copy them directly from textbooks. The experience also shows the viability of creating a framework that might be suitable for other academic domains and grade levels by attempting a multifactorial solution in a complex context. Abstract issue tools variables teaching mitigated classmates online textbooks context

SUMMARY OBJECTIVE: The objective of this study was to evaluate cytogenetic changes in individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use through the micronucleus test in oral mucosa. METHODS: This study consisted of 37 individuals, of whom 17 comprised the pre-exposure prophylaxis group and 20 comprised the control group. A total of 2,000 cells per slide were analyzed for the determination of micronuclei, binucleation, nuclear buds, and cytotoxicity parameters: pyknosis, karyolysis, and karyorrhexis (KR), in a double-blind manner. The repair index was also evaluated in this setting. RESULTS: In the mutagenicity parameters, the pre-exposure prophylaxis group showed increased frequencies of micronuclei (p=0.0001), binucleation (p=0.001), and nuclear buds (p=0.07). Regarding the cytotoxicity parameters, there was an increase with a statistical difference (p≤0.05) in the karyorrhexis frequency (p=0.001). Additionally, the repair system efficiency decreased in the pre-exposure prophylaxis group. CONCLUSION: These results indicate that individuals undergoing pre-exposure prophylaxis use have geno- and cytotoxicity in oral mucosal cells.

Resumo Fundamento A classificação funcional da New York Heart Association (NYHA) é o sistema de classificação mais utilizado para a insuficiência cardíaca (IC), enquanto o teste de exercício cardiopulmonar (TECP) é o padrão ouro para a avaliação do estado funcional na IC. Objetivo Analisar a correlação e a concordância entre as classes da NYHA e as variáveis do TECP. Métodos Foram selecionados pacientes com IC com indicação clínica para TECP e fração de ejeção (FE) < 50%. A correlação (coeficiente de Spearman) e a concordância (kappa) entre a classificação da NYHA e as classificações baseadas no TECP foram analisadas. Um valor de p < 0,05 foi considerado significativo. Resultados No total, foram incluídos 244 pacientes no estudo. A idade média foi de 56±14 anos, e a FE média foi de 35,5%±10%. A distribuição de pacientes de acordo com a classificação da NYHA foi a seguinte: classe I (31,2%), classe II (48,3%), classe III (19,2%) e classe IV (1,3%). A correlação (r) entre as classes da NYHA e de Weber foi de 0,489 (p < 0,001), e a concordância foi de 0,231 (p < 0,001). A correlação (r) entre as classes da NYHA e ventilatórias (inclinação da ventilação minuto/produção de dióxido de carbono [VE/VCO2]) foi de 0,218 (p < 0,001), e a concordância foi de 0,002 (p = 0,959). A correlação de Spearman entre as classes da NYHA e do escore TECP foi de 0,223 (p = 0,004), e a concordância kappa foi de 0,027 (p = 0,606). Conclusão Foi identificada uma associação moderada entre as classes da NYHA e de Webber, embora a concordância tenha sido baixa. As classes ventilatórias (inclinação VE/VCO2) e do escore TECP apresentaram uma associação fraca e uma baixa concordância com as classes da NYHA.

Abstract Background The New York Heart Association (NYHA) functional classification is the most commonly used classification system for heart failure (HF), whereas cardiopulmonary exercise testing (CPET) is the gold standard for functional status evaluation in HF. Objective This study aimed to analyze correlation and concordance between NYHA classes and CPET variables. Methods HF patients with clinical indication for CPET and ejection fraction (EF) < 50% were selected. Correlation (Spearman coefficient) and concordance (kappa) between NYHA classification and CPET-based classifications were analyzed. A p < 0.05 was accepted as significant. Results In total, 244 patients were included. Mean age was 56 ± 14 years, and mean EF was 35.5% ± 10%. Distribution of patients according to NYHA classification was 31.2%% class I, 48.3% class II, 19.2% class III, and 1.3% class IV. Correlation (r) between NYHA and Weber classes was 0.489 (p < 0.001), and concordance was 0.231 (p < 0.001). Correlation (r) between NYHA and ventilatory classes (minute ventilation/carbon dioxide production [VE/VCO2] slope) was 0.218 (p < 0.001), and concordance was 0.002 (p = 0.959). Spearman correlation between NYHA and CPET score classes was 0.223 (p = 0.004), and kappa concordance was 0.027 (p = 0.606). Conclusion There was a moderate association between NYHA and Weber classes, although concordance was low. Ventilatory (VE/VCO2slope) and CPET score classes had a weak association and a low concordance with NYHA classes.

Abstract In this article, we present the analysis of a problemsolving activity performed during a chemical technician course. We examine the contributions of the teaching sequence when implemented in the development of conceptual, procedural, and attitudinal learning, focusing on environmental issues related to pesticides. In our investigation, we also report the perception of students regarding the teaching and learning processes. The research was carried out in a public school in the city of Porto Alegre, Brazil, involving 29 students of the chemical technician course. The students solved problems created to address different approaches concerning pesticides. Data were obtained by the analysis of the researchers’ field diaries and questionnaires of the class in which the students participated in the problem-solving activity. The results showed that the teaching sequence favoured conceptual, procedural, and attitudinal learning related to problem-solving and the environmental hazards that pesticides can cause. It was observed that the problem-solving methodology favoured the students’ autonomy, which is the ability to self-govern, to make one’s own decisions, and to be critical and reflective.

Resumen En este artículo presentamos el análisis de una actividad de resolución de problemas realizada durante un curso de técnico químico. Examinamos las contribuciones de la secuencia enseñanza cuando se implementa en el desarrollo del aprendizaje conceptual, procedimental y actitudinal, enfocándonos en temas ambientales relacionados con plaguicidas. En nuestra investigación, también reportamos la percepción de los estudiantes sobre procesos de enseñanzas y de aprendizajes. La investigación se llevó a cabo en una escuela pública de la ciudad de Porto Alegre, Brasil, con la participación de 29 estudiantes del curso de técnico químico. Los estudiantes resolvieron problemas creados para abordar diferentes enfoques relacionados con los pesticidas. Los datos se obtuvieron mediante el análisis de los diarios de campo de los investigadores y los cuestionarios de la clase en la que los estudiantes participaron en la actividad de resolución de problemas. Los resultados mostraron que la secuencia enseñanza favoreció el aprendizaje conceptual, procedimental y actitudinal relacionado con la resolución de problemas y los daños ambientales que pueden causar los plaguicidas. Se observó que la metodología de resolución de problemas favoreció la autonomía de los estudiantes, que es la capacidad de autogobernarse, tomar sus propias decisiones, ser crítico y reflexivo.

This paper evaluates the effect of adding glycerol to the electrodeposition bath on the deposition efficiency and characteristics of Ni-Mo coating in concentrations ranging from 0.07 to 0.82 mol.L-1. Evaluation of the corrosion resistance was performed by means of weight loss tests in four different periods of immersion. Electrochemical techniques, such as obtaining polarization curves, linear polarization resistance, corrosion current density, corrosion potential, and electrochemical impedance spectroscopy were applied. Corrosion measurements were obtained in 0.5 mol.L-1 NaCl acid solution and 0.5 mol.L-1 NaOH alkaline solution. The morphology and microstructures of electrodeposited were analyzed using Scanning Electron Microscopy and Spectrometry X-Ray Diffraction. The effect of glycerol on Ni-Mo hardness was evaluated by Vickers microhardness measurements. The presence of glycerol in the electrodeposition bath increased the grain size and decreased the hardness of the coating. However, it promoted the formation of a more compact and less porous coating, increasing the corrosion resistance of the coating. Moreover, the addition of 0.82 mol.L-1 glycerol increases current efficiency, thereby reducing the amount of energy consumed during electroplating.

Resumo A corrosão é um dos principais fenômenos que geram manifestações patológicas nas estruturas de concreto armado em ambientes agressivos, sendo o íon cloro o maior responsável por sua ocorrência. Desta forma, entender os mecanismos de transporte deste íon através da microestrutura do concreto é de fundamental importância para impedir ou retardar a penetração destes agentes agressivos, visando garantir uma estrutura durável. Na literatura são vastos os estudos referentes à difusão de cloretos em concreto e a influência das adições pozolânicas neste mecanismo, entretanto, poucos correlacionam os diferentes métodos de análise. Assim, este trabalho visa determinar os coeficientes de difusão do íon cloro em concretos contendo diversos teores de adição de sílica ativa (5%, 10% e 15%) ou com variação do teor de argamassa (54%, 80% e 100%), comparando os resultados obtidos por meio dos ensaios de migração iônica e de coluna. Observou-se que, apesar das técnicas utilizadas serem bastante distintas, os valores de coeficientes de difusão obtidos foram semelhantes, colaborando para a validação de ambas as técnicas. Além disso, a variação no teor de argamassa acarreta uma redução na zona de transição interfacial agregado graúdo/argamassas e um aumento no teor de aluminatos, o que promove efeito semelhante ao uso de sílica ativa.

Abstract Corrosion is one of the main phenomena that lead to pathological manifestations in reinforced concrete structures under aggressive environments. with the chloride ion being the most responsible for its occurrence. In this way, understanding the transport mechanisms of this ion through the microstructure of the concrete is of fundamental importance to prevent or delay the penetration of these aggressive agents to guarantee a durable structure. In the literature, there are extensive studies concerning the diffusion of chlorides in concrete and the influence of pozzolanic additions in this mechanism. However, only a few correlate the different methods of analysis. This work aims to determine the chloride ion diffusion coefficients in concrete containing various levels of silica fume (5%, 10%, and 15%) or varying the mortar content (54%, 80%, and 100%), and compares the results obtained through column tests and chloride migration tests. It was observed that, although the techniques used were quite distinct, the diffusion values obtained were similar, contributing to the validation of both techniques. Furthermore, the variation in the mortar ratio causes a reduction in the interfacial transition zone of coarse aggregate/mortars and an increase in the content of aluminates, which promotes a similar effect to the use of silica fume.

Resumo A Síndrome Respiratória Aguda Grave é uma doença causada pelo novo coronavírus, cuja disseminação em escala mundial causou a pandemia da Covid-19. Este artigo tem por base a espacialização de dados governamentais relativos à capital fluminense, combinada com entrevistas e outros tipos de informações. Parte de uma perspectiva teórica que considera a ação de diferentes agentes na contribuição dos processos socioespaciais. A elaboração deste artigo teve por base o boletim Mapa Social do Corona , realizado pelo Observatório de Favelas, entre junho e agosto de 2020, que contou com a colaboração de uma equipe interdisciplinar em parceria com diferentes instituições e profissionais. Evidenciou-se como a desigualdade socioespacial contribuiu para uma taxa maior de letalidade nos bairros populares.

Abstract Severe Acute Respiratory Syndrome (SARS-COV-2) is a disease caused by the new coronavirus, whose dissemination across the world has caused the Covid-19 pandemic. This article is based on the spatialization of governmental data about the city of Rio de Janeiro, combined with interviews and other types of information. It starts from a theoretical perspective that considers the action of different agents in the contribution of socio-spatial processes. The writing of the article was grounded in the bulletin “Mapa Social do Corona” (Social Map of the Coronavirus), issued by Observatório de Favelas between June and August 2020 with the collaboration of an interdisciplinary team, in partnership with different institutions and professionals. It shows that socio-spatial inequality has contributed to a higher lethality rate in low--income neighborhoods.