Pesquisa | SciELO

Resumo Calvatia é um gênero de fungos gasteroides que compreende cerca de 47 espécies em todo o mundo. Neste artigo relatamos a segunda ocorrência de duas espécies pouco conhecidas de Calvatia, registradas no bioma Cerrado do Brasil: C. oblongispora e C. nodulata. Descrições morfológicas detalhadas e ilustrações são fornecidas, incluindo micrografias eletrônicas de varredura de hifas e basidiósporos, bem como uma discussão sobre sua taxonomia e distribuição geográfica.

Abstract Calvatia is a genus of gasteroid fungi, comprising about 47 species worldwide. In this paper we report the second worldwide occurrence of two poorly known species of Calvatia, recorded in the Cerrado biome of Brazil: C. oblongispora and C. nodulata. Detailed morphological descriptions and illustrations, including scanning electron micrographs of hyphae and basidiospores are provided, as well a discussion on their taxonomy and geographic distribution.

https://doi.org/10.1590/1519-6984.247840 493 downloads

Human footprint effects on the distribution of the spotted lowland paca (Cuniculus paca)
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Sánchez-Reyes, Monserrat

; Chiappa-Carrara, Xavier

; Vázquez-Domínguez, Ella

; Yáñez-Arenas, Carlos

; Falconi, Manuel

; Osorio-Olvera, Luis

; Contreras-Díaz, Rusby G.

Therya

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2023, Volume 14 Nº 1 Páginas 75 - 83

Resumo: Es En | Texto: Es En | PDF: Es | PDF: En

Resumen La actividad humana ha disminuido alrededor del 20 % de la diversidad biológica del planeta, así como del 25 % de la abundancia de los vertebrados. Esto ha llevado a mamíferos herbívoros grandes y medianos a extinguirse localmente, desatando una cascada de cambios en los ecosistemas. El tepezcuintle (Cuniculus paca) sufre una importante presión antropogénica debido a la cacería y pérdida de hábitat, por lo que es importante estimar sus efectos sobre su distribución para su conservación y manejo. Modelamos la distribución del tepezcuintle mediante el uso de datos primarios de biodiversidad de acceso libre, variables bioclimáticas, cobertura arbórea y un índice de huella humana que refleja la presión antropogénica sobre los ecosistemas. De 105 modelos candidatos, únicamente uno cumplió con los criterios de selección. Las variables con la mayor contribución fueron la huella humana y la precipitación anual. A partir de las curvas de respuesta del modelo, se observó en la especie una tolerancia a la antropización de baja a media. Estos resultados podrían deberse a que en ambientes antropizados los depredadores del tepezcuintle han disminuido sus tamaños poblacionales. Entender los costos y beneficios de la perturbación antropogénica es esencial para la conservación del tepezcuintle.

Abstract Human activity has caused the decrease of about 20 % of the planet's vertebrate diversity and 25 % in their abundance. Many large and medium-sized herbivore mammals have gone extinct locally, unleashing a cascade of ecosystem changes. The spotted paca (Cuniculus paca) is impacted by hunting and anthropogenic habitat fragmentation and loss. To protect spotted pacas, it is essential to estimate anthropogenic effects on their geographic distribution. Through the use of primary biodiversity data, bioclimatic data, land-cover data, and a human footprint index, we modeled the distribution of C. paca. From 105 candidate models, only one model met our selection criteria. The variables with the highest contribution were the human footprint and annual precipitation. According to the model's performance curves, the spotted paca has low to medium tolerance of anthropogenic pressure. Cuniculus paca tolerates low to medium anthropogenic disturbance, which we hypothesize is related to reduced predator pressure in habitats modified by humans. Accounting for the costs and benefits of anthropogenic disturbance is essential to paca conservation.

https://doi.org/10.12933/therya-23-2237

Molecular Docking in silico Analysis of Brazilian Essential Oils Against Host Targets and SARS-CoV-2 Proteins
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Costa, Rêmullo B. G. M.

; Martins, Regildo M. G.

; Lima, Gerlane S. de

; Stamford, Thayza C. M.

; Tadei, Wanderli P.

; Maciel, Maria Aparecida M.

; Rêgo, Amália C. M. do

; Xavier-Júnior, Francisco H.

Journal of the Brazilian Chemical Society

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Out 2022, Volume 33 Nº 10 Páginas 1219 - 1235

Resumo: En | Texto: En | PDF: En

The inhibitory activity of thirty-one sesquiterpenes identified from Brazilian essential oils (Copaifera langsdorffii Desf., Croton cajucara Benth. and Siparuna guianensis Aublet.) were analyzed by in silico molecular docking. The compounds were characterized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame-ionization detection (GC-FID), and then, applied against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) proteins and human angiotensin-converting enzyme 2 (hACE2). Applying molecular docking and AutoDock Vina software, a total of 496 individual interactions were detected for sesquiterpenes along with SARS-CoV-2 proteins and hACE2 human angiotensin converting enzyme-2 protein. The findings showed considerable binding affinity of sesquiterpenes with the tested macromolecules. In that, β-selinene from C. langsdorffii displayed the best energy (−7.2 kcal mol-1) and showed strong interactions with the amino acids of the SARS-CoV-2 M-Pro protein. Spathulenol from C. cajucara strongly interacted with human ACE2, with a binding energy of −7.1 kcal mol-1. Meanwhile, γ-eudesmol from S. guianensis presented the lowest binding energy (−7.5 kcal mol-1) by interacting with the SARS-CoV-2 M-Pro complex. Additionally, measurements were performed aiming to evaluate the best sesquiterpenes binding interactions with the main proteins and its homologue files. According to results, these Brazilian essential oils hold antiviral potential being a rich source for further in vitro and in vivo studies focusing on herbal therapeutic adjuvants against SARS-CoV-2 infections.

https://doi.org/10.21577/0103-5053.20220043

Enhanced Catalytic Performance of Strontium-Doped Lanthanum Manganites by the Presence of Molybdenum Oxides for Electro-Reduction of Hydrogen Peroxide
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Xavier, Ludmila G. O.

; Ebambi, Thérèse C.

; Diniz, Renata

; Lins, Vanessa F. C.

; Montoro, Luciano A.

; Matencio, Tulio

Journal of the Brazilian Chemical Society

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Jun 2022, Volume 33 Nº 6 Páginas 589 - 599

Resumo: En | Texto: En | PDF: En

In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and with (LSMMO) mixed molybdenum oxides, were synthesized by the sol-gel route and deposited by immersion in carbon cloth substrates. Their performance as cathodes in the hydrogen peroxide reduction reaction (HPRR) and oxygen reduction reaction (ORR) was investigated through cyclic voltammetry and electrochemical impedance spectroscopy, the electrocatalytic efficiency of these electrodes in the HPRR was analyzed in KOH and H2O2 medium at 298 K. The performance of the cathodes, in a single compartment, using a nickel plate as an anode was also investigated. The results showed that for the reduction reactions, electrodes developed with LSMMO have more significant catalytic activity than LSM after polarization, resulting in 32% higher current densities, lower electrical resistance after polarization, and a 21% increase in power density.

https://doi.org/10.21577/0103-5053.20220016

Effective recommendations towards healthy routines to preserve mental health during the COVID-19 pandemic
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Pilz, Luísa K.

; Couto Pereira, Natividade S.

; Francisco, Ana Paula

; Carissimi, Alicia

; Constantino, Débora B.

; Caus, Letícia B.

; Abreu, Ana Carolina O.

; Amando, Guilherme R.

; Bonatto, Fernanda S.

; Carvalho, Paula V.V.

; Cipolla-Neto, José

; Harb, Ana

; Lazzarotto, Gabriela

; Marafiga, Joseane Righes

; Minuzzi, Luciano

; Montagner, Francisco

; Nishino, Fernanda A.

; Oliveira, Melissa A.B.

; dos Santos, Bruno G.T.

; Steibel, Eduardo G.

; Tavares, Patrice S.

; Tonon, André C.

; Xavier, Nicóli B.

; Zanona, Querusche Klippel

; Amaral, Fernanda G.

; Calcagnotto, Maria Elisa

; Frey, Benicio N.

; Hidalgo, Maria Paz

; Idiart, Marco

; Russomano, Thais

Brazilian Journal of Psychiatry

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Abr 2022, Volume 44 Nº 2 Páginas 136 - 146

Resumo: En | Texto: En | PDF: En

Objective: To assess the adherence to a set of evidence-based recommendations to support mental health during the coronavirus disease 2019 (COVID-19) pandemic and its association with depressive and anxiety symptoms. Methods: A team of health workers and researchers prepared the recommendations, formatted into three volumes (1: COVID-19 prevention; 2: Healthy habits; 3: Biological clock and sleep). Participants were randomized to receive only Volume 1 (control), Volumes 1 and 2, Volumes 1 and 3, or all volumes. We used a convenience sample of Portuguese-speaking participants over age 18 years. An online survey consisting of sociodemographic and behavioral questionnaires and mental health instruments (Patient Health Questionnaire-9 [PHQ-9] and Generalized Anxiety Disorder-7 [GAD-7]) was administered. At 14 and 28 days later, participants were invited to complete follow-up surveys, which also included questions regarding adherence to the recommendations. A total of 409 participants completed the study – mostly young adult women holding university degrees. Results: The set of recommendations contained in Volumes 2 and 3 was effective in protecting mental health, as suggested by significant associations of adherence with PHQ-9 and GAD-7 scores (reflecting anxiety and depression symptoms, respectively). Conclusion: The recommendations developed in this study could be useful to prevent negative mental health effects in the context of the pandemic and beyond.

https://doi.org/10.1590/1516-4446-2021-2109

Perception of fungi by farmers in the Cerrado
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Calaça, F. J. S.

; Sousa, D. G.

; Belém-Junior, J. S.

; Faquim, R. C. P.

; Xavier-Santos, S.

; Silva-Neto, C. M.

; Souza, M. M. O.

Brazilian Journal of Biology

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2022, Volume 82 elocation e236219

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Resumo Percepção dos fungos por agricultores do Cerrado – Fungos são organismos importantes em vários aspectos da vida humana. Em particular, para a agricultura, fungos patogênicos são de grande importância, pois são responsáveis por perdas de produção dos mais diversos tipos. Por isso, o conhecimento sobre fungos patogênicos é de extrema importância para agricultores e profissionais que trabalham em áreas agrícolas. Entre os agricultores que utilizam práticas agroecológicas, esse conhecimento é ainda mais valioso, pois, ao não adotar métodos convencionais de produção, recorrem a alternativas não invasivas que são menos ou não prejudiciais ao meio ambiente, considerando os métodos de gerenciamento da produção. Este estudo teve como objetivo avaliar a percepção de um grupo de agricultores do bioma Cerrado, na cidade de Goiás (GO), Brasil, a fim de compreender suas percepções etnomicológicas, de modo a verificar práticas históricas de manejo, seu conhecimento sobre fungos fitopatogênicos e como esses produtores percebem os fungos, de modo geral. Utilizamos o método “de camponês para camponês”, formulado pela ANPA – Associação Nacional de Pequenos Agricultores. Discutimos alguns aspectos do conhecimento etnomicológico destes agricultores. A facilidade de identificação de representantes fúngicos está associada a organismos que apresentam características facilmente reconhecíveis, como estereótipo orelha-de-pau ou fungos causadores de doenças em cultivares. Em geral, os agricultores do estudo são capazes de identificar representantes do Reino Fungi que são encontrados em suas vidas cotidianas. A percepção dos agricultores sobre os fungos, um grupo ainda muito desconhecido pela sociedade, é muito relevante para ações futuras dentro da etnomicologia.

Abstract Fungi are important in several aspects of human life. In particular, to agriculture, pathogenic fungi are of great importance, as they are responsible for production losses of the most diverse types. Because of this, knowledge about pathogenic fungus is of extreme importance for farmers and professionals working in agricultural areas. Among farmers who use specific agroecological practices, this knowledge is even more valuable, since by not adopting conventional methods of production, they resort to non-invasive alternatives that are less or not harmful at all to the environment in consideration of production management methods. This study aimed to assess farmer perception in the Cerrado biome in the city of Goiás (GO), Brazil, in order to understand their ethnomycological perceptions to verify historical management practices, their knowledge about phytopathogenic fungi, and how these producers perceive fungi. We used the theoretical reference method “From peasant to peasant” formulated by ANPA - National Association of Small Farmers. Some aspects of farmers’ ethnomycological knowledge are discussed. These ease identification the representatives of the Fungi Kingdom is associated with organisms that present easily recognizable characteristics, such as wood-ears or disease-causing fungi. In general, farmers are able to identify representatives of the Fungi Kingdom that are found in their daily lives. The perception of farmers about fungi, a group still much unknown by society, is very relevant for future actions of ethnomycology.

https://doi.org/10.1590/1519-6984.236219 467 downloads

Enigmatic wood and first evidence of tetrapods in the Yaguarí Formation (Middle-Late Permian), Uruguay
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Piñeiro, G.

; Marchetti, L.

; Mármol, S.

; Celio, A.

; Xavier, P.

; Francia, M.

; Schultz, C.

Agrociencia Uruguay

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2022, Volume 26 Nº nspe1 elocation e504

Resumo: Es En Pt | Texto: Es En Pt | PDF: Es | PDF: En | PDF: Pt

Resumen: Este artículo describe un intrigante fósil recientemente descubierto en niveles de areniscas finas a medias de la sección superior de la Formación Yaguarí de Uruguay. La naturaleza y las afinidades de este espécimen no fueron inicialmente fáciles de determinar, a pesar de ser sometido a numerosos estudios, incluido un análisis anatómico-comparativo complementado con la preparación de secciones delgadas y análisis de su microestructura bajo Microscopio Electrónico de Barrido. La microestructura mostrada por las láminas delgadas en corte transversal permitió finalmente resolver el problema sobre discernir entre una naturaleza animal o vegetal del espécimen, siendo la última la aceptada. El detallado estudio comparativo de las secciones delgadas reveló que el espécimen es un fragmento de madera relacionado al complejo Dadoxylon-Araucarioxylon. Asimismo, para proveer una mejor calibración temporal de los depósitos de la sección superior de la Formación Yaguarí (Miembro Villa Viñoles), también se incluye en este trabajo una descripción preliminar de huellas de tetrápodos recientemente halladas en esta unidad, las cuales representan la primera evidencia de la presencia de tetrápodos en niveles de la Formación Yaguarí (sensu Elizalde et al., 1970) subyacentes a los conglomerados portadores de la Fauna de Colonia Orozco. Las huellas fueron asignadas a los icnotaxa cf. Karoopes isp., cf. Capitosauroides isp. y cf. Pachypes isp., sugiriendo la presencia de terápsidos gorgonópsidos y therocefalidos y de pareiasauromorfos, respectivamente. La edad Pérmico Medio a Tardío recientemente sugerida para la Formación Yaguarí, basado en estudios de paleomagnetismo sustentados por dataciones radioisotópicas, es congruente con la aportada por los fósiles aquí descriptos, que, aunque fragmentarios, constituyen descubrimientos preliminarmente relevantes para depósitos cuyo potencial fosilífero no ha sido aún explorado.

Abstract: This article describes an intriguing fossil material recently found in the fine-grained sandstone levels from the upper section of the Yaguarí Formation of Uruguay. The nature of this specimen and its relationships were, initially, not easy to determine with confidence although it was subjected to several analyses, such as morphological and comparative examination complemented with preparation of thin sections and microanatomical and chemical studies under SEM. However, the anatomical structure shown in the performed transversal thin sections allowed solving the issue on the different animal or plant interpretations of the fossil specimen, which was finally discerned in favor of the latter. Therefore, after a detailed comparative study of the thin sections, we concluded that the specimen is a wood fragment related to the Dadoxylon-Araucarioxylon complex. Moreover, in order to provide a better biostratigraphic calibration for these deposits until now devoid of fossils, we include a preliminary description of recently found fossil footprints, which represent the first evidence of the presence of tetrapods in levels of the Yaguarí Formation (sensu Elizalde et al., 1970), below the conglomerates that have yielded the Colonia Orozco Fauna. The footprints were preliminary assigned to the ichnotaxa cf. Karoopes isp, cf. Capitosauroides isp., and cf. Pachypes isp., suggesting the presence of gorgonopsids and therocephalian therapsids and pareiasauromorphs, respectively. The Middle-Late Permian age recently suggested for the Yaguarí Formation based on paleomagnetic and radioisotopic studies is here supported by the described fossils, which thus constitute preliminary but nonetheless relevant discoveries for deposits whose fossiliferous potential has yet to be explored.

Resumo: Este artigo descreve um intrigante material fóssil achado recentemente nos níveis de arenito fino da seção superior da Formação Yaguarí no Uruguai. A natureza deste espécime e suas relações não foram, em um primeiro momento, facilmente determináveis, apesar do mesmo ter sido submetido a várias análises. Estas incluíram avaliações preliminares comparativas e de morfologia, complementadas com preparação de lâminas delgadas, e estudos microanatômicos e químicos em MEV. A estrutura anatômica observada nas seções delgadas transversais permitiu solucionar as controversas interpretações do espécime fóssil, animal ou planta, o qual foi finalmente discernido em favor da última. Por enquanto, depois do estudo detalhado das lâminas delgadas o espécime foi relacionado a o complexo Dadoxylon-Araucarioxylon. Além disso, para permitir uma melhor calibração bioestratigráfica para estes depósitos até então desprovidos de fósseis, incluímos uma descrição preliminar de pegadas fósseis recém-encontradas, as quais são a primeira evidência a presença de tetrápodes em níveis da Formação Yaguarí (sensu Elizalde et al., 1970), abaixo dos conglomerados que forneceram a Fauna de Colonia Orozco. As pegadas foram assignadas aos ichnotaxa cf. Karoopes isp., cf. Capitosauroides isp. e cf. Pachypes isp., sugerindo a presença de terápsidos gorgonopsídeos e terocefalídeos e de pareiasauromorfos, respectivamente. Uma idade Meso-Neopermiano recentemente sugerida para a Formação Yaguarí baseada em estudos paleomagnéticos e radiométricos é aqui suportada pelos fósseis descritos, os quais, apesar de serem descobertas preliminares, fornecem dados relevantes para depósitos cujo potencial fossilífero ainda está para ser explorado.

https://doi.org/10.31285/agro.26.504

COVID-19 with and without pneumonia: clinical outcomes in the internal medicine ward
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Melendi, Santiago E.

; Pérez, María M.

; Salas, Cintia E.

; Haedo, Mariana F.

; Xavier, Franco B.

; Navarrete, Jandry D. Saltos

; Aguirre, Camila

; Baleta, María L.

; Balsano, Facundo J.

; Caldano, Mariano G.

; Colignon, María G.

; De Oliveira Brasil, Thayana

; De Wolodimeroff, Nicolás

; Déramo Aquino, Andrea I.

; Fernández De Córdova, Ana G.

; Fontan, María B.

; Galvagno, Florencia I.

; Iturrieta Araya, Noelia S.

; Mollinedo Cruz, Volga S.

; Olivero, Agustín

; Pestalardo, Ignacio

; Ricciardi, María

; Vera Rueda, María L.

; Villaverde, María C.

; Mauri, Marcela Lauko

; Ujeda, Carlos

; Leis, Rocío

Medicina (Buenos Aires)

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Dez 2020, Volume 80 Supl. 6 Páginas 56 - 64

Resumo: En Es | Texto: En Es | PDF: En | PDF: Es

Abstract The clinical features of COVID-19 differ substantially upon the presence (or absence) of viral pneumonia. The aim of this article was to describe the clinical characteristics of COVID-19 patients admitted to the Internal Medicine ward, as divided into those with and without pneumonia. This single-center prospective cohort study was conducted in a tertiary teaching public hospital in Buenos Aires City named Hospital General de Agudos Carlos G. Durand. Baseline data collection was performed within 48 hours of admission and patients were followed until discharge or in-hospital death. Epidemiological, clinical, laboratory, and radiological characteristics together with treatment data were obtained from the medical records. Of the 417 included, 243 (58.3%) had pneumonia. Median age was 43 years (IQR:32-57) and 222 (53.2%) were female. The overall crude case-fatality rate was 3.8%. None of the COVID-19 patients without pneumonia developed critical disease, required invasive mechanical ventilation nor died during hospitalization. However, 7 (4%) developed severe disease during follow-up. Among patients with COVID-19 pneumonia, in-hospital mortality rate was 6.6%, severe disease developed in 81 (33.3%), critical disease in 23 (9.5%), and 22 (9.1%) were admitted to the intensive care unit. A largely good prognosis was observed among COVID-19 patients without pneumonia, still, even among this group, unfavorable clinical progression can develop and should be properly monitored. Critical illness among patients with COVID-19 pneumonia was frequent and observed rates from this cohort provide a sound characterization of COVID-19 clinical features in a major city from South America.

Resumen Las características clínicas del COVID-19 difieren sustancialmente según la presencia (o ausencia) de neumonía viral. El objetivo de este artículo fue describir las características clínicas de los pacientes con COVID-19 internados en el servicio de Clínica Médica, divididos en pacientes con y sin neumonía. Fue un estudio de cohorte prospectivo, con base en un único centro, realizado en un hospital público de la ciudad de Buenos Aires: Hospital General de Agudos Carlos G. Durand. La recolección basal de datos se realizó dentro de las 48 horas del ingreso y los pacientes fueron seguidos hasta el alta o la muerte hospitalaria. Las características epidemiológicas, clínicas, de laboratorio y radiológicas junto con los datos del tratamiento se obtuvieron de la historia clínica. De los 417 incluidos, 243 (58.3%) tenían neumonía. La mediana de edad fue de 43 años (RIC: 32-57) y 222 (53.2%) eran mujeres. La tasa global de letalidad fue del 3.8%. Ninguno de los pacientes con COVID-19 sin neumonía desarrolló enfermedad crítica, requirió ventilación mecánica invasiva ni falleció durante la hospitalización. Sin embargo, 7 (4%) desarrollaron enfermedad grave durante el seguimiento. Entre aquellos con neumonía COVID-19, la tasa de mortalidad hospitalaria fue del 6.6%, se desarrolló enfermedad grave en 81 (33.3%), enfermedad crítica en 23 (9.5%) y 22 (9.1%) fueron trasladados a la unidad de cuidados intensivos. Los pacientes con COVID-19 sin neumonía presentaron buen pronóstico; sin embargo, incluso en este grupo, se observaron algunos con progresión clínica desfavorable, por lo que se requirió seguimiento adecuado. En los pacientes con neumonía por COVID-19, el desarrollo de enfermedad crítica fue frecuente y las tasas observadas en esta cohorte proporcionan una caracterización sólida de las características clínicas de los pacientes con COVID-19 en una importante ciudad de América del Sur.

174 downloads

Analysis of deformability modulus by linear and nonlinear elastic methods in ceramic structural masonry and mortars
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Cerqueira, N. A.

; Marvila, M. T.

; Azevedo, A. R. G. de

; Alexandre, J.

; Xavier, G. C.

; Souza, V. B. de

Cerâmica

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Set 2020, Volume 66 Nº 379 Páginas 229 - 235

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Resumo Existem estudos analisando os parâmetros de resistência de alvenaria estrutural, porém poucos são realizados avaliando a interferência da argamassa nos parâmetros de deformabilidade. O objetivo deste estudo foi verificar teorias de elasticidade (modelo linear de Hooke e modelos não lineares de Ghosh, de Duffing e de Martin, Roth e Stiehler) aplicados a alvenaria estrutural. Foram confeccionados blocos cerâmicos prensados e queimados a 890 ºC e argamassas na proporção 1:1:5:0,5:2 de cimento: cal hidratada: areia: cola PVA: água. Os materiais foram ensaiados à compressão individualmente e em prismas com e sem a utilização das argamassas. Os resultados obtidos com a análise linear elástica mostraram-se incoerentes uma vez que o módulo de deformabilidade obtido para os prismas com argamassa foi maior do que os sem argamassa. Realizando a análise pelas teorias não lineares, verificou-se que os resultados obtidos foram mais coerentes, principalmente pela teoria de Duffing, que utiliza um parâmetro para rigidez e outro para amortecimento do material.

Abstract There are studies analyzing the parameters of structural masonry strength, however few are performed evaluating the interference of the mortar in the deformability parameters. The objective of this study was to verify the theories of elasticity (Hooke’s linear model and nonlinear models by Ghosh, Duffing, and Martin, Roth, and Stiehler) applied to structural masonry. Ceramic blocks were pressed and fired at 890 ºC and mortars prepared with the proportion 1:1:5:0.5:2 of cement: hydrated lime: sand: PVA binder: water. The materials were tested in compression individually and in prisms with and without the use of mortars. The results obtained with the linear elastic analysis were incoherent since the deformability modulus obtained for the mortar prisms was higher than those without mortar. Performing the analysis by nonlinear theories, it was found that the results obtained were more coherent, mainly by Duffing’s theory that uses one parameter for stiffness and another for damping of the material.

https://doi.org/10.1590/0366-69132020663792845 696 downloads

10.

Performance, metabolic efficiency and egg quality in Japanese quails fed with acidulated soybean soapstock and lecithin for a prolonged period
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BAVARESCO, CAROLINE

; SILVA, SUELEN N.

; DIAS, RENATA C.

; LOPES, DÉBORA C.N.

; XAVIER, EDUARDO G.

; ROLL, VICTOR F.B.

Anais da Academia Brasileira de Ciências

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2020, Volume 92 elocation e20180620

Resumo: En | Texto: En | PDF: En

Abstract This study aimed to evaluate the use of acidulated soybean soapstock in association with lecithin on productive performance, metabolic efficiency in the utilization of nutrientes, and the egg quality of Japanese quails. A total of 192 quails were used, distributed randomly in a 2×2×2 factorial scheme that included two types of oils, two levels of supplementation (4% and 8%) and two levels of lecithin (1% or 0%). At the end of the six-month experimental period, some double significant interactions were shown between the level of oil and lecithin for the performance variables (egg weight p=0.04, feed intake p<0.01 and feed conversion rate p=0.04). The feed conversion rate also was influenced by a double significant interaction between the type of oil and the level of oil (p<0.01). The nutrient digestibility showed that different interactions affected the results. The evaluation of egg quality, was verified that the use of acidulated soybean soapstock did not affect most variables of internal quality. The results showed that it is possible to use 8% acidulated soybean soapstock in combination with 1% lecithin in the diets of Japanese quails for a period of up to six months without a reduction in performance.

https://doi.org/10.1590/0001-3765202020180620 565 downloads

11.

Experimental analysis of bolts employed as shear connectors in circular concrete-filled tube columns
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XAVIER, E. M.

; R. NETO, J. G.

; SARMANHO, A. M. C.

; ROQUETE, L.

; PAULA, L. G. C. De

Revista IBRACON de Estruturas e Materiais

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Abr 2019, Volume 12 Nº 2 Páginas 337 - 370

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Resumo Este estudo apresenta análises experimentais e teóricas do uso de parafusos como conectores de cisalhamento em pilares mistos de aço em seção tubular circular preenchidos com concreto (PMPCs). Os resultados obtidos experimentalmente são comparados com os resultados das formulações propostas pela norma ABNT NBR 16239:2013. Os ensaios são de cisalhamento direto, variando parâmetros como diâmetro e comprimento dos parafusos, quantidade de conectores e resistência do concreto. A partir dos resultados experimentais observou-se que as equações da ABNT NBR 16239:2013 estão a favor da segurança, e é proposta uma adequação das formulações da norma para considerar o efeito do confinamento do concreto. Verificou-se também que o aumento do diâmetro e comprimento do parafuso aumenta a capacidade de carga do conector, porém a variação da quantidade de parafusos e da resistência do concreto não interferem na sua capacidade de carga.

Abstract This paper presents experimental and theoretical analysis of bolts employed as shear connectors in circular concrete-filled steel tube columns (CFTs). The theoretical results, obtained from ABNT NBR 16239:2013 formulations, were compared with the experimental results. A series of push-out tests were carried out, where the diameter and length of the bolts, the number of connectors and the concrete strength were varied. From the experimental results, it was observed that the equations from ABNT NBR 16239:2013 are conservative. Therefore, it is proposed an adjustment to the formulations in order to consider the concrete confinement. It was also verified that increments in the diameter and the length of the bolt increase the load capacity of the connector. However, the variation of the quantity of bolts and the concrete strength did not interfere in the load capacity.

https://doi.org/10.1590/s1983-41952019000200008 988 downloads

12.

New Synthesis Method for a Core-Shell Composite Based on α-Bi2O3 @PPy and its Electrochemical Behavior as Supercapacitor Electrode
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Xavier, Fárlon F. S.

; Bruziquesi, Carlos G. O.

; Fagundes, Wélique S.

; Matsubara, Elaine Y.

; Rosolen, José M.

; Silva, Adilson C.

; Canobre, Sheila C.

; Amaral, Fábio A.

Journal of the Brazilian Chemical Society

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Abr 2019, Volume 30 Nº 4 Páginas 727 - 735

Resumo: En | Texto: En | PDF: En

New composite based on polypyrrole (PPy) and bismuth oxide (α-Bi2O3) was investigated as supercapacitor electrode. The α-Bi2O3 was obtained by hydrothermal route at 500 ºC for 2 h. Cyclic voltammetry was used to electropolymerize PPy on graphite electrode (GE) or on GE/α-Bi2O3. The X-ray diffraction profile of Bi2O3 revealed the α-Bi2O3 monoclinic structure with space group P21/c.The scanning and transmission electron microscopy images showed that PPy coated α-Bi2O3. Raman spectra showed that PPy inhomogeneously coated α-Bi2O3, but it was still possible to obtain a α-Bi2O3 @PPy core-shell hybrid composite with highly ordered α-Bi2O3 with electronic interaction between the oxide and the polymer chain of the polymer. The GE/α-Bi2O3@PPy composite electrode (type I supercapacitor) displayed a predominantly capacitive profile with low impedance values and good electrochemical stability after 50 charge and discharge cycles. The specific capacitance of α-Bi2O3 @PPy composite was found in the range of 634 to 301 F g-1 to gravimetric current of 3 and 10 A g-1, respectively.

https://doi.org/10.21577/0103-5053.20180192 819 downloads

13.

Relationship between Electrochemical Parameters, Cytotoxicity Data against Cancer Cells of 3-Thio-Substituted Nor-Beta-Lapachone Derivatives. Implications for Cancer Therapy
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Paiva, Yen G. de

; Silva, Thaissa L.

; Xavier, André F. A.

; Cardoso, Mariana F. C.

; Silva, Fernando C. da

; Silva, Maria F. S.

; Pinheiro, Daniel P.

; Pessoa, Claudia

; Ferreira, Vitor F.

; Goulart, Marilia O. F.

Journal of the Brazilian Chemical Society

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Mar 2019, Volume 30 Nº 3 Páginas 658 - 672

Resumo: En | Texto: En | PDF: En

Electrochemical methods are powerful in the characterization and design of redox-modulating agents. We, herein, report the electrochemical investigation, in aprotic medium, of eleven synthetic 3-thio-substituted-nor-beta-lapachones, along with the determination of cytotoxic activity and correspondent selectivity index, against several cancer cell lines and one normal cell. Four of the quinones are novel compounds. The redox behavior is representative of two independent systems: the easy reduction of the quinone moiety and, at far more negative potential, the reductive cleavage of the C-S-C bonding; and the anodic part controlled by the oxidation of the sulfur moiety. The compounds have shown relevant cytotoxic activity, with emphasis on 3-phenyl-thio-2,2-dimethyl-2,3-dihydronaphtho[1,2-b]furan-4,5-dione (compound 2), which mechanism of molecular action was shown to be related to reactive oxygen species (ROS) release. Despite the absence of a linear correlation, there is a trend: the majority of the thionaphthoquinones, with values of first wave reduction potential, less negative than -0.65 V, were active. The less electrophilic compound (3-(cyclohexylthio)-2,2-dimethyl-2,3-dihydronaphtho[1,2-b]furan-4,5-dione, cyclohexyl derivative) is also the less cytotoxic toward cancer cells. Agents containing chalcogens and quinones can be used to attack entities with a disturbed redox balance.

https://doi.org/10.21577/0103-5053.20180248 741 downloads

14.

Characterization and biological activity of condensed tannins from tropical forage legumes
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Pereira, Tatiana Pires

; Modesto, Elisa Cristina

; Nepomuceno, Delci de Deus

; Oliveira, Osniel Faria de

; Freitas, Rafaela Scalise Xavier de

; Muir, James Pierre

; Dubeux Junior, José Carlos Batista

; Almeida, João Carlos de Carvalho

Pesquisa Agropecuária Brasileira

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Set 2018, Volume 53 Nº 9 Páginas 1070 - 1077

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Resumo: O objetivo deste trabalho foi caracterizar taninos condensados de seis leguminosas forrageiras e determinar sua atividade biológica. Os monômeros propelargonidina, prodelfinidina e procianidina foram analisados, assim como taninos condensados extraíveis (TCE), taninos condensados ligados a proteínas (TCLP) e ligados a fibras (TCLF), massa molecular, grau de polimerização, índice de polidispersão e atividade biológica, por meio de proteínas precipitadas por fenóis (PPF), em folhas das leguminosas Cajanus cajan, Gliricidia sepium, Stylosanthes capitata x Stylosanthes macrocephala (estilosantes), Flemingia macrophylla, Cratylia argentea e Mimosa caesalpiniifolia, e na casca desta última espécie. Foram observadas diferenças nas concentrações de TCE, TCLP, PPF e total de taninos condensados entre as espécies, mas não na de TCLF. O maior valor de TCLP ocorreu em F. macrophylla. O total de TC variou de não detectável em C. argentea à maior concentração em folhas de M. caesalpiniifolia, que contêm os maiores níveis de PPF. Não se observaram diferenças quanto ao grau de polimerização em estilosantes, F. macrophylla e M. caesalpiniifolia. Folhas de estilosantes, C. cajan e G. sepium, todas com total de TC entre 20 e 50 g kg-1, poderiam ser fontes benéficas de TC, se oferecidas como única fonte de alimentos em dietas de ruminantes. A proporção prodelfinidina:procianidina variou de 10:80 (stylo) a 65:35 (F. machrophylla), e a propelargonidina é determinada somente em C. argentea.

Abstract: The objective of this work was to characterize condensed tannins (CT) from six tropical forage legumes and to determine their biological activity. The monomers propelargonidin, prodelphinidin and procyanidin were analyzed, as well as extractable condensed tannin (ECT), protein-bound CT (PBCT) and fiber-bound CT (FBCT), molecular weight, degree of polymerization, polydispersity index, and biological activity by protein precipitate by phenols (PPP) of leaves of the legumes Cajanus cajan, Gliricidia sepium, Stylosanthes capitata x Stylosanthes macrocephala (stylo), Flemingia macrophylla, Cratylia argentea, and Mimosa caesalpiniifolia, and of the bark of this latter species. Differences were observed in the concentrations of ECT, PBCT, PPP, and total condensed tannin among species, but not in that of FBCT. The highest value of PBCT occurred in F. macrophylla. Total CT varied from nondetected concentration in C. argentea to the highest concentration in M. caesalpiniifolia leaves that contain the greatest levels of PPP. No differences were observed for polymerization degree in stylo, F. macrophylla, and M. caesalpiniifolia. Leaves of stylo, C. cajan, and G. sepium, all containing between 20 and 50 g kg-1 total CT, should be beneficial CT sources, if offered as sole feeds in ruminant diets. The ratio of prodelphinidin:procyanidin varies from 10:80 (stylo) to 65:35 (F. machrophylla), and propelargonidin is only determined in C. argentea.

https://doi.org/10.1590/s0100-204x2018000900011 1167 downloads

15.

3ª Diretriz Brasileira de Transplante Cardíaco
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Bacal, Fernando

; Marcondes-Braga, Fabiana G.

; Rohde, Luis Eduardo Paim

; Xavier Júnior, José Leudo

; Brito, Flávio de Souza

; Moura, Lídia Ana Zytynski

; Colafranceschi, Alexandre Siciliano

; Lavagnoli, Carlos Fernando Ramos

; Gelape, Cláudio Leo

; Almeida, Dirceu Rodrigues

; Gaiotto, Fábio Antônio

; Atik, Fernando Antibas

; Figueira, Fernando Augusto M. S.

; Souza, Germano Emílio Conceição

; Rodrigues, Hélcio

; Campos, Iáscara Wozniak

; Souza Neto, João David de

; Rossi Neto, João Manoel

; Gasparetto, Juliano

; Goldraich, Lívia Adams

; Benvenuti, Luiz Alberto

; Seguro, Luis Fernando B. C.

; Ulhôa Júnior, Marcelo Botelho

; Moreira, Maria da Consolação V.

; Ávila, Mônica Samuel

; Carneiro, Rodrigo

; Mangini, Sandrigo

; Ferreira, Sílvia Moreira Ayub

; Strabelli, Tânia Mara

Arquivos Brasileiros de Cardiologia

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Ago 2018, Volume 111 Nº 2 Páginas 230 - 289

Resumo: Pt | Texto: Pt | PDF: Pt

https://doi.org/10.5935/abc.20180153 28659 downloads

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