Análise experimental da evolução da carbonatação em argamassas de cal aérea / Experimental analysis of carbonating evolution in air lime mortars

Durante séculos, o cal aéreo tem sido frequentemente usado como ligante para preparar argamassa em edifícios de alvenaria. Contudo, o conhecimento sobre o comportamento material das argamassas aéreas de cal ainda é reduzido, e são necessárias contribuições para o melhor entendimento de suas propriedades físicas e mecânicas. Neste trabalho, é realizado um programa experimental para investigar a evolução do processo de carbonatação. Começa com a definição de composição da argamassa, sendo adotada uma composição típica. As amostras com espessura reduzida foram armazenadas em três câmaras diferentes. A primeira câmara apresenta condições ambientais comuns, enquanto os outros dois ambientes apresentam umidade elevada ou concentração de CO2. A análise termogravimétrica foi realizada às cinco idades, e os resultados indicam um aumento progressivo da carbonatação; no entanto, foi observado um processo incompleto de carbonatação, sendo adotada uma normalização. Os dados mostram um processo de carbonatação mais rápido para a amostra armazenada na câmara com CO2 elevado e uma evolução reduzida da argamassa armazenada na câmara úmida nas primeiras idades.

O Sínodo da Amazônia e os dilemas do catolicismo

O presente artigo pretende apreciar, reflexivamente, a proposta do Sínodo da Amazônia convocado pelo Papa Francisco – a realizar-se em Roma em 2019. Os documentos preparatórios e as reações internas e externas à Igreja, demonstram a importância social, ecológica, econômica, cultural, política e religiosa deste evento, que poderíamos chamar de momento inflexivo. No contexto mais amplo, percebemos o esforço de reconfigurar o catolicismo na Amazônia. A partir de metodologia qualitativa teórica, com revisão bibliográfica parcial, combinada às reflexões sobre alguns sinais extra e intrainstitucionais investigaremos que caminhos o catolicismo está trilhando na Amazônia e na contemporaneidade

Aerodynamic characterization of lateral forces due to vortex shedding in slender buildings with rectangular cross-section

O projeto de uma estrutura esbelta exige o conhecimento dos fatores ambientais que venham a impactá-la estatica e dinamicamente. No caso desse tipo de estrutura, a ação do vento é um fator determinante a ser considerado na avaliação do comportamento estrutural na sua fase de projeto. Nesse sentido, um fenômeno dinâmico importante relacionado à ação do vento em estruturas é o desprendimento de vórtices. Ao longo dos anos as pesquisas sobre o tema avançaram com o intuito de caracterizar o fenômeno, estimar suas ações e mitigar seus efeitos. Diante desse contexto, diversos pesquisadores vêm empenhando esforços para propor metodologias e procedimentos técnicos que façam previsões suficientemente precisas a respeito das respostas que a estrutura pode apresentar quando submetida às condições do fenômeno de desprendimento de vórtices, seja a estrutura de seção circular, retangular ou qualquer outra. Quando se trata de estruturas de seção retangular os estudos ainda necessitam ser mais explorados, frente a isso, o presente trabalho busca abordar o fenômeno para o caso destas estruturas com o intuito de contribuir com a caracterização aerodinâmica das forças laterais provenientes do fenômeno de desprendimento de vórtices. A partir da análise dos dados extraídos de cada modelo estudado foi possível a obtenção dos coeficientes r.m.s. da força lateral e dos espectros da força lateral possibilitando assim a caracterização das relações dimensionais de estruturas de seção retangular e sua suscetibilidade em sofrer os efeitos do desprendimento de vórtices.The design of a slender structure requires knowledge of the environmental factors that can statically and dynamically impact it. In the case of this type of structure, wind action is a crucial factor to be considered in the evaluation of structural behavior during the design phase. In this regard, an important dynamic phenomenon related to wind action on structures is vortex shedding. Over the years, research on this topic has advanced with the aim of characterizing the phenomenon, estimating its effects, and mitigating its consequences. In this context, numerous researchers have been making efforts to propose methodologies and technical procedures that provide sufficiently accurate predictions regarding the responses that a structure may exhibit when subjected to vortex shedding conditions, whether the structure has a circular, rectangular, or any other cross-section. When it comes to structures with rectangular cross-sections, studies are still scarce. Therefore, this study aims to address the phenomenon specifically for structures of this type, with the objective of contributing to the aerodynamic characterization of the lateral forces resulting from vortex shedding. By analyzing the data extracted from each studied model, it was possible to obtain the r.m.s. coefficients of lateral force and the spectra of lateral force. This enabled the characterization of dimensional relationships in structures with rectangular cross-sections and their susceptibility to experiencing vortex shedding effects

Effects of Fish Oil Supplementation on Oxidative Stress Biomarkers and Liver Damage in Hypercholesterolemic Rats

Metabolic syndrome, especially its component related to dyslipidemia, is related to the development of nonalcoholic fatty liver disease (NAFLD), which is a disease with a significant global prevalence. Supplementation with omega-3 polyunsaturated fatty acids emerged as a complementary therapeutic possibility for dyslipidemia, but its benefits are questioned. This paper aims at evaluating the effects of fish oil supplementation in rats with hypercholesterolemia induced by hypercholesterolemic diet (HD). The study design is based on an experimental model in which the animals were randomly divided into 3 groups: G1 (standard commercial feed + saline solution); G2 (hypercholesterolemic diet + saline solution) and G3 (hypercholesterolemic diet + fish oil) over a period of 16 weeks. Metabolic control parameters and oxidative stress biomarkers were evaluated according to standardized methodologies. The G3 group showed significantly lower values of plasma concentrations of TG, and hepatic myeloperoxidase as well as higher erythrocyte superoxide dismutase activity (p < 0.05). Regarding histopathological analysis, there was lipid accumulation in the liver of animals from group G2; meanwhile, hepatocytes reorganization and expressive reduction of lipid vacuoles and hepatic TG content was observed in group G3. This study demonstrated how fish oil supplementation reduced the plasma concentration and hepatic content of triglycerides, as well as liver tissue damage in histopathological analysis

Effects of ω-3 PUFA-Rich Oil Supplementation on Cardiovascular Morphology and Aortic Vascular Reactivity of Adult Male Rats Submitted to an Hypercholesterolemic Diet

Atherosclerosis is a cardiovascular disease associated with abnormalities of vascular functions. The consumption of mono- and polyunsaturated fatty acids can be considered a strategy to reduce clinical events related to atherosclerosis. In the present study, we investigated the effects of supplementation with 310 mg of ω-3 PUFAs (2:1 eicosapentaenoic/docosahexaenoic acids) for 56 days on rats with hypercholesterolemia induced by a diet containing cholesterol (0.1%), cholic acid (0.5%), and egg yolk. Serum biochemical parameters were determined by the enzymatic colorimetric method. Assessment of vascular effects was performed by analysis of histological sections of the heart and aortic arch stained with hematoxylin and eosin and vascular reactivity of the aorta artery. We observed that treatment with ω-3 PUFAs did not promote alterations in lipid profile. On the other hand, we documented a favorable reduction in liver biomarkers, as well as contributions to the preservation of heart and aortic arch morphologies. Interestingly, the vascular reactivity of rat thoracic aortic preparations was improved after treatment with ω-3 PUFAs, with a decrease in hyperreactivity to phenylephrine and increased vasorelaxation promoted by acetylcholine. Our findings suggest that the supplementation of hypercholesterolemic rats with ω-3 PUFAs promoted improvement in liver and vascular endothelial function as well as preserving heart and aortic tissue, reinforcing the early health benefits of ω-3 PUFAs in the development of atherosclerotic plaque and further related events

Increased interregional virus exchange and nucleotide diversity outline the expansion of chikungunya virus in Brazil

Abstract The emergence and reemergence of mosquito-borne diseases in Brazil such as yellow fever, zika, chikungunya, and dengue have had serious impacts on public health. Concerns have been raised due to the rapid dissemination of the chikungunya virus across the country since its first detection in 2014 in Northeast Brazil. In this work, we carried out on-site training activities in genomic surveillance in partnership with the National Network of Public Health Laboratories that have led to the generation of 422 chikungunya virus genomes from 12 Brazilian states over the past two years (2021–2022), a period that has seen more than 312 thousand chikungunya fever cases reported in the country. These genomes increased the amount of available data and allowed a more comprehensive characterization of the dispersal dynamics of the chikungunya virus East-Central-South-African lineage in Brazil. Tree branching patterns revealed the emergence and expansion of two distinct subclades. Phylogeographic analysis indicated that the northeast region has been the leading hub of virus spread towards other regions. Increased frequency of C > T transitions among the new genomes suggested that host restriction factors from the immune system such as ADAR and AID/APOBEC deaminases might be driving the genetic diversity of the chikungunya virus in Brazil

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease