Colunas mistas parcialmente revestidas: efeito da resistência e rigidez na resistência à flambagem sob ação do fogo

Colunas mistas, parcialmente revestidas com concreto, apresentam melhor desempenho estrutural que colunas apenas de aço. O concreto entre os banzos do perfil metálico, aumenta a resistência ao fogo da coluna, além da resistência e rigidez, sendo necessário determinar esta propriedade para estes elementos estruturais. O Eurocódigo 4 parte 1-2, no anexo G, apresenta um método simplificado de cálculo para determinar a resistência ao fogo das colunas mistas parcialmente revestidas, calculando a resistência à flambagem, em relação ao eixo de menor momento de segunda ordem, quando expostas a curva de incêndio padrão. Estudos feitos por A. Fellouh e melhorados por L. Calió, determinam que a norma apresenta resultados inseguros, propondo novas equações e parâmetros para o método da soma ponderada presente no anexo G. Neste sentido, o presente trabalho visa propor um novo aprimoramento para o modelo simplificado de cálculo, utilizando novas formulações, provenientes dos resultados de simulações térmicas transientes não lineares, utilizando o programa ANSYS. Foram estudadas trinta configurações de colunas mistas parcialmente revestidas, sendo dez perfis de cada uma das seguintes séries, HEB, HD e UC. Os resultados das simulações numéricas foram usados para realizar o aprimoramento do modelo, sendo este comparado com a sua atual versão do Eurocódigo. Os resultados obtidos com a atual proposta para o modelo, apresentam valores mais seguros, quando comparados com a atual versão do Eurocódigo. Existe uma boa concordância entre os resultados numéricos e o novo modelo de solução proposto.Composite columns, partially encased with concrete, present a better structural performance than bare steel columns. The concrete between the flanges, increases the fire resistance of the column, besides the strength and stiffness, being necessary to determine this property for this type of structural element. The Eurocode 4, in the annex G, presents a simplified calculation method to determine the fire resistance of the partially encased columns, calculating the buckling resistance, around the weak axis, when exposed to the standard fire curve. Studies developed by A. Fellouh and improved by L. Calió, concluded for unsafe results when using the Eurocode, proposing new equations and parameters for the balanced summation model presented in the annex G. This study aims to propose a new improvement for the simplified calculation model, using new formulae, based on thermal transient nonlinear simulation result, developed with the software ANSYS. This investigation deals with thirty different cross sections of partially encased columns, being ten of each specified for the profile series, HEB, HD and UC. The numerical simulation results were used to improve the model, being this solution compared with the current version of Eurocode. The results obtained with the current proposal model present safer values when compared with the current version of Eurocode. There is a good agreement between the numerical results and the new proposed solution model

Structural Model of the hUbA1-UbcH10 Quaternary Complex: In Silico and Experimental Analysis of the Protein-Protein Interactions between E1, E2 and Ubiquitin

UbcH10 is a component of the Ubiquitin Conjugation Enzymes (Ubc; E2) involved in the ubiquitination cascade controlling the cell cycle progression, whereby ubiquitin, activated by E1, is transferred through E2 to the target protein with the involvement of E3 enzymes. In this work we propose the first three dimensional model of the tetrameric complex formed by the human UbA1 (E1), two ubiquitin molecules and UbcH10 (E2), leading to the transthiolation reaction. The 3D model was built up by using an experimentally guided incremental docking strategy that combined homology modeling, protein-protein docking and refinement by means of molecular dynamics simulations. The structural features of the in silico model allowed us to identify the regions that mediate the recognition between the interacting proteins, revealing the active role of the ubiquitin crosslinked to E1 in the complex formation. Finally, the role of these regions involved in the E1–E2 binding was validated by designing short peptides that specifically interfere with the binding of UbcH10, thus supporting the reliability of the proposed model and representing valuable scaffolds for the design of peptidomimetic compounds that can bind selectively to Ubcs and inhibit the ubiquitylation process in pathological disorders

Structural model of the hUbA1-UbcH10 quaternary complex: In silico and experimental analysis of the protein-protein interactions between E1, E2 and ubiquitin

UbcH10 is a component of the Ubiquitin Conjugation Enzymes (Ubc; E2) involved in the ubiquitination cascade controlling the cell cycle progression, whereby ubiquitin, activated by E1, is transferred through E2 to the target protein with the involvement of E3 enzymes. In this work we propose the first three dimensional model of the tetrameric complex formed by the human UbA1 (E1), two ubiquitin molecules and UbcH10 (E2), leading to the transthiolation reaction. The 3D model was built up by using an experimentally guided incremental docking strategy that combined homology modeling, protein-protein docking and refinement by means of molecular dynamics simulations. The structural features of the in silico model allowed us to identify the regions that mediate the recognition between the interacting proteins, revealing the active role of the ubiquitin crosslinked to E1 in the complex formation. Finally, the role of these regions involved in the E1-E2 binding was validated by designing short peptides that specifically interfere with the binding of UbcH10, thus supporting the reliability of the proposed model and representing valuable scaffolds for the design of peptidomimetic compounds that can bind selectively to Ubcs and inhibit the ubiquitylation process in pathological disorders

Polymer composites reinforced with natural fibers and nanocellulose in the automotive industry: a short review

Environmental concerns and cost reduction have encouraged the use of natural fillers as reinforcement in polymer composites. Currently, a wide variety of reinforcement, such as natural fibers and nanocellulose, are used for this purpose. Composite materials with natural fillers have not only met the environmental appeal, but also contribute to developing low-density materials with improved properties. The production of natural fillers is unlimited around the world, and many species are still to be discovered. Their processing is considered beneficial since the natural fillers do not cause corrosion or great wear of the equipment. For these reasons, polymer reinforced with natural fillers has been considered a good alternative for obtaining ecofriendly materials for several applications, including the automotive industry. This review explores the use of natural fillers (natural fibers, cellulose nanocrystals, and nanofibrillated cellulose) as reinforcement in polymer composites for the automotive industry323172016/09588-9; 2016/09588-9; 2016/09588-9CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paul

Improving the earthquake resilience of primary schools in the border regions of neighbouring countries

This work summarises the strategy adopted in the European research project PERSISTAH. It aims to increase the resilience of the population, focusing on the existing primary schools in the Algarve (Portugal) and Huelva (Spain) regions. Software was developed to assess the seismic safety of these schools, considering different earthquake scenarios. Seismic retrofitting measures were studied and numerically tested. Some of them were also implemented in the retrofitting activities of two case study schools (one in each country). It was found that the adopted ground motion prediction equations (GMPEs) considerably affect the results obtained with the software, especially for offshore earthquake scenarios. Furthermore, the results show that the masonry buildings would be the most damaged school typologies for all the scenarios considered. Additionally, a set of guidelines was created to support the school community and the technicians related to the construction industry. The goal of these documents is to increase the seismic resilience of the population. Different activities were carried out to train schoolteachers in seismic safety based on the guidelines produced, obtaining positive feedback from them.info:eu-repo/semantics/publishedVersio

Diet, DNA methylation and systemic lupus erythematosus: evidence and perspectives focused on personalized nutrition

Background: The pathoetiology of systemic lupus erythematosus (SLE) involves a multifactorial interaction consisting of various genetic, epigenetic and environmental factors. Considering epigenetic characteristics, notable alterations in DNA methylation, particularly hypomethylation in immune-related pathways, such as T cell receptor have been observed. In turn, these alterations are associated with the overexpression of genes related to autoimmunity and a loss of immunological self-tolerance. Furthermore, DNA hypomethylation levels in SLE may contribute to disease progression and also impact disease activity and clinical manifestations. Summary: It is well-established that nutritional epigenetics elucidates the role of nutrition and dietary factors on the interactions of metabolic systems with the molecules that bind to DNA, regulating gene expression. Specific nutritional interventions may reverse initial epigenetic patterns, thereby significantly impacting the chronic disease´s treatment and prognostic. In fact, dietary nutrients and bioactive food compounds may influence DNA methylation patterns by inhibiting enzymes related to DNA methylation reactions or by altering the availability of different substrates involved in DNA methylation process (e.g methyl-donor nutrients). Key Messages: The knowledge of how diet plays a role in changing DNA methylation patterns in SLE is in the early stages. While a few studies in the literature have assessed the effects of nutrient intake, supplementation, or treatment on DNA methylation levels and have demonstrated their relevance, further research is imperative to deepen our comprehension of the interactions between epigenetics and nutrients, which is vital for the development of novel precision nutrition approaches

Biomarkers for prediction of mortality in left-sided infective endocarditis

Background: Evidence regarding biomarkers for risk prediction in patients with infective endocarditis (IE) is limited. We aimed to investigate the value of a panel of biomarkers for the prediction of in-hospital mortality in patients with IE. Methods: Between 2016 and 2018, consecutive IE patients admitted to the emergency department were prospectively included. Blood concentrations of nine biomarkers were measured at admission (D0) and on the seventh day (D7) of antibiotic therapy: C-reactive protein (CRP), sensitive troponin I (s-cTnI), procalcitonin, B-type natriuretic peptide (BNP), neutrophil gelatinase-associated lipocalin (NGAL), interleukin 6 (IL6), tumor necrosis factor α (TNF-α), proadrenomedullin, alpha-1-acid glycoprotein, and galectin 3. The primary endpoint was in-hospital mortality. Results: Among 97 patients, 56% underwent cardiac surgery, and in-hospital mortality was 27%. At admission, six biomarkers were independent predictors of in-hospital mortality: s-cTnI (OR 3.4; 95%CI 1.8–6.4; P < 0.001), BNP (OR 2.7; 95%CI 1.4–5.1; P = 0.002), IL-6 (OR 2.06; 95%CI 1.3–3.7; P = 0.019), procalcitonin (OR 1.9; 95%CI 1.1–3.2; P = 0.018), TNF-α (OR 1.8; 95%CI 1.1–2.9; P = 0.019), and CRP (OR 1.8; 95%CI 1.0–3.3; P = 0.037). At admission, S-cTnI provided the highest accuracy for predicting mortality (area under the ROC curve: s-cTnI 0.812, BNP 0.727, IL-6 0.734, procalcitonin 0.684, TNF-α 0.675, CRP 0.670). After 7 days of antibiotic therapy, BNP and inflammatory biomarkers improved their performance (s-cTnI 0.814, BNP 0.823, IL-6 0.695, procalcitonin 0.802, TNF-α 0.554, CRP 0.759). Conclusion: S-cTnI concentration measured at admission had the highest accuracy for mortality prediction in patients with IE

Status of Muon Collider Research and Development and Future Plans

The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides continued work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy collider, many studies are now concentrating on a machine near 0.1 TeV (CoM) that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay ($\pi \to \mu \nu_{\mu}$) channel, muon cooling, acceleration, storage in a collider ring and the collider detector. We also present theoretical and experimental R & D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This report is an update of the progress on the R & D since the Feasibility Study of Muon Colliders presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A. Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics (Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics, Accelerators and Beam

Carotid intima-media thickness and flow-mediated dilation do not predict acute in-hospital outcomes in patients hospitalized with COVID-19

Studies have suggested a potential role of endothelial dysfunction and atherosclerosis in the pathophysiology of COVID-19. Herein, we tested whether brachial flow-mediated dilation (FMD) and carotid intima-media thickness (cIMT) measured upon hospital admission are associated with acute in-hospital outcomes in patients hospitalized with COVID-19. A total of 211 patients hospitalized with COVID-19 were submitted to assessments of FMD and mean and maximum cIMT (cIMTmean and cIMTmax) within the first 72 h of hospital admission. Study primary outcome was a composite of intensive care unit admission, mechanical ventilation, or death during the hospitalization. These outcomes were also considered independently. Thrombotic events were included as a secondary outcome. Odds ratios (ORs) and confidence intervals (CIs) were calculated using unadjusted and adjusted multivariable logistic regression models. Eighty-eight (42%) participants demonstrated at least one of the composite outcomes. cIMTmean and cIMTmax were predictors of mortality and thrombotic events in the univariate analysis (cIMTmean and mortality: unadjusted OR 12.71 [95% CI 1.71–94.48]; P = 0.014; cIMTmean and thrombotic events: unadjusted OR 11.94 [95% CI 1.64–86.79]; P = 0.015; cIMTmax and mortality: unadjusted OR 8.47 [95% CI 1.41–51.05]; P = 0.021; cIMTmax and thrombotic events: unadjusted OR 12.19 [95% CI 2.03–73.09]; P = 0.007). However, these associations were no longer present after adjustment for potential confounders (P > 0.05). In addition, FMD% was not associated with any outcome. In conclusion, cIMT and FMD are not independent predictors of clinical outcomes in patients hospitalized with COVID-19. These results suggest that subclinical atherosclerosis and endothelial dysfunction may not be the main drivers of COVID-19 complications in patients hospitalized with COVID-19