366 research outputs found

    Clinical correlation between N-terminal pro-b-type natriuretic peptide and angiographic coronary atherosclerosis

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    OBJECTIVES: This study aimed to investigate the clinical correlation between angiographic coronary atherosclerosis and N-terminal pro-B-type natriuretic peptide along with other known correlated factors. METHODS: In total, 153 patients with a diagnostic hypothesis of stable angina, unstable angina or acute myocardial infarction were classified as group A (patients with angiographically normal coronary arteries) or group B (patients with angiographic coronary atherosclerosis). The two groups were analyzed with respect to the following factors: gender, age, body mass index, abdominal circumference, smoking, diabetes mellitus, arterial hypertension, early family history of atherosclerosis, statin use, the presence of metabolic syndrome, clinical presentation and biochemical factors, including cholesterol, creatinine and fibrinogen plasma concentrations, monocyte counts and N-terminal pro-B-type natriuretic peptide. RESULTS: Univariate analyses comparing the two groups revealed that group B patients more frequently had diabetes, used statins and had systolic dysfunction, N-terminal pro-B-type natriuretic peptide levels ≄250 pg/mL, fibrinogen levels >;500 mg/dL and ≄501 monocytes/mm3 compared with group A patients (

    Mechanical characterization of PDMS with different mixing ratios

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    Polydimethylsiloxane (PDMS) is a transparent, biocompatible, flexible, simple processing, chemically and thermally stable polymer that has been attracting attention due to its wide range of applications in mechanical, civil and electronic engineering and biomedical field. In order to improve PDMS’ properties, many studies have been investigating the effect of the mixing ratios of its components (base polymer and curing agent) on the mechanical properties, once they affect the number of interactions between the polymer chains of the material. With the aim to make a comparison of the mechanical response of pure PDMS (SYLGARD 184) with different ratios of the base elastomer and the curing agent, tensile and hardness tests were performed. The tested mixing ratios were 10:1, 10:2 and 10:3 (base: curing agent). Tensile tests were executed in a universal tester machine, set up with a velocity of 500 mm/min and pre-load of 1 N. An analogical portable durometer type Shore A was used to carry out the hardness test, according to ASTM D2240. The results for the tensile test showed that an increase in the amount of cure agent reduced the tensile strength. The hardness values obtained were 41.7±0.95, 43.2±1.03 and 37.2±1.14 Shore A for pure PDMS with ratios equal to 10:1, 10:2 and 10:3, respectively.This research was partially funded through the base funding from the following research units: UIDB/00690/2020 (CIMO).info:eu-repo/semantics/publishedVersio

    Stress Concentration on PDMS: An evaluation of three numerical constitutive models using digital image correlation

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    The examination of hyperelastic materials’ behavior, such as polydimethylsiloxane (PDMS), is crucial for applications in areas as biomedicine and electronics. However, the limitations of hyperelastic models for specific stress scenarios, with stress concentration, are not well explored on the literature. To address this, firstly, three constitutive models were evaluated (Neo-Hookean, Mooney-Rivlin, and Ogden) using numerical simulations and Digital Image Correlation (DIC) analysis during a uniaxial tensile test. The samples were made of PDMS with stress concentration geometries (center holes, shoulder fillets, and edge notches). Results of ANOVA analysis showed that any of the three models can be chosen for numerical analysis of PDMS since no significant differences in suitability were found. Finally, the Ogen model was chosen to obtain the stress concentration factors for these geometries, a property which characterize how discontinuities change the maximum stress supported by an element. Our study provides new values for variables needed to analyze and design hyperelastic elements and produce a foundation for understanding PDMS stress-strain behavior.The authors acknowledge the projects EXPL/EME-EME/0732/2021 and 2022.06207.PTDC for the financial support, through national funds (OE), within the scope of the Scientific Research and Technological Development Projects (IC&DT) program in all scientific domains (PTDC), PORTUGAL 2020 Partnership Agreement, European Regional Development Fund (FEDER), via the Foundation for Science and Technology, I.P. (FCT, I.P) and the R&D Units projects (UIDB/00690/2020 and UIDP/00690/2020) (CIMO), SusTEC (LA/P/0007/2020), UIDB/ 04077/2020, UIDP/04077/2020, UIDB/04436/2020 and UIDB/00532/ 2020. Andrews Souza acknowledges FCT for the Ph.D. scholarship 2021.07961.BD.info:eu-repo/semantics/publishedVersio

    PU tensile tests: conventional and digital image correlation analysis

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    Polyurethane (PU) is a polymer, used as coating, paint, foam, adhesive, and even in biomedical devices. To furthermore expand its applications, it can be combined with additives such as Calcium Carbonate (CaCO3), an inexpensive material, widely available in nature, or with fibers, such as glass fibers explored in several sectors, likewise the aerospace and automobile industries. To determine the mechanical properties of these materials, the tensile test is the most used due to its great ease of application and flexibility. However, conventional processes, such as the use of strain gauges or crosshead displacement data, may not provide detailed information about the strain field, or cannot be able to evaluate the Poisson's ratio and the true stresses for the entire stressstrain curve. Thus, digital image correlation (DIC) methods are a promising alternative, consisting of strain field measurement without contact with the surface of the structure. In this context, this study carried out the tensile characterization of two main polyurethane samples: one petrochemical, distributed by Sika (R), reinforced with type E glass fiber: and the other, natural, manufactured by Kehl (R) from castor oils, and combined with CaCO3 particles. During the tests, DIC was applied to evaluate the Poisson's ratio and, subsequently, Scanning Electron Microscopy (SEM) analyses were performed, revealing a higher number of bubbles on Sika's polymer, which contributes to the reduction of the maximum supported stresses, since these pores, with dimensions of up to 25 hm, were regions where the cracks started and headed the breakage. Poisson's ratios were all around 0.4 and the highest tensile strength values were obtained from E-glass reinforced samples (TS015), around 117.24 +/- 13.20MPa. CaCO3 particles also acted as reinforced, increasing maximum stress reached from 20MPa to values between 29 and 37MPa.This research was partially funded through the base funding from the following research units: UIDB/00690/2020 (CIMO).info:eu-repo/semantics/publishedVersio

    Cultivo de Calophyllum braziliense em vårzea e terraço fluvial e seleção de espécies para a conversão agroflorestal.

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    O cultivo agroflorestal de Guanandi - Calophyllum braziliense nas vĂĄrzeas e terraços fluviais do Vale do ParaĂ­ba Ă© sustentĂĄvel e representa baixo impacto ambiental na principal bacia hidrogrĂĄfica da regiĂŁo Sudeste do Brasil. Este estudo de caso contĂ©m informaçÔes do Projeto desenvolvido na centenĂĄria Fazenda Coruputuba, em Pindamonhangaba, SP. Aborda aspectos ecofisiolĂłgicos do gĂȘnero Calophyllum que torna o guanandi apto ao cultivo sob inundação e contĂ©m uma seleção de espĂ©cies adaptadas aos dois ambientes: vĂĄrzea inundĂĄvel e terraço fluvial

    Growth, feed intake, carcass characteristics, and meat fatty acid profile of lambs fed soybean oil partially replaced by fish oil blend

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    AbstractThe objective of this study was to evaluate the effects of partial replacement of soybean oil by fish oil on dry matter intake (DMI), growth, carcass characteristics, and meat fatty acid profile of feedlot lambs. Fifty Santa Ines male lambs with 17.1±2.8 of initial body weight (BW) were individually penned and used in a randomized complete block design with 10 blocks and 5 treatments. Dietary treatments, dry matter (DM) basis, consisted of: (1) control diet (CONT) with a 10:90 of forage to concentrate ratio, (2) control diet supplemented with 40g/kg of soybean oil (0FO), (3) control diet supplemented with 2.5g/kg of fish oil blend+37.5g/kg of soybean oil (25FO), (4) control diet supplemented with 5g/kg of fish oil blend+35g/kg of soybean oil (50FO), and (5) control diet supplemented with 7.5g/kg of fish oil blend+32.5g/kg of soybean oil (75FO). Diets were mixed once daily and fed ad libitum. At the end of the 84-day feeding trial, all animals were slaughtered for carcass characteristics evaluations and meat fat acid profile determination. Animals fed soybean oil had reduced DMI compared to control; however, the average daily gain (ADG), feed efficiency (FE) and final BW were not affected. The animals fed fish oil had similar DMI, ADG, FE and final BW to those receiving the control treatment. The DMI, ADG, FE and final BW were not affected by the increasing substitution of soybean oil for fish oil. Most carcass characteristics were not affected by treatments. The shrink after chilling was lower for the 50FO diet. Short, medium, and long-chain fatty acids were similar for all diets. Stearic acid concentration was higher for lambs fed the fat diets vs. control. However, stearic acid concentration decreased linearly when fish oil replaced soybean oil. Vaccenic acid concentration was higher for lambs fed fat diets vs. control. In addition, vaccenic acid increased linearly with fish oil inclusion. The conjugated linoleic acid (CLA) C18:2 cis-9, trans-11 showed higher concentration in meat of animals fed diets containing fish oil compared to control, but it was not affected by soybean oil inclusion. Feeding small amounts of fish oil blend plus soybean oil does not exert an additional effect on the concentration of CLA C18:2 cis-9, trans-11 in relation to the exclusive use of soybean oil. However, the mixture of 7.5g/kg DM of fish oil blend with 32.5g/kg DM of soybean oil is recommended, because it improves the lipid profile of the meat by increasing the concentration of vaccenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Additionally, supplementing 7.5g/kg DM of fish oil blend mixed with 32.5g/kg DM of soybean had no negative effect on the feed intake, ADG, FE and carcass characteristics of the lambs fed high concentrate diet

    Desenvolvimento de um coletor solar flexĂ­vel e de baixo custo

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    CIES2020 - XVII Congresso IbĂ©rico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Esse trabalho reporta o desenvolvimento numĂ©rico de um coletor solar flexĂ­vel e de baixo custo e a posterior fabricação de protĂłtipos, em filme de poliuretano (PU). Foram projetados quatro modelos de coletores solares no software SolidWorksÂź e realizadas simulaçÔes no software ANSYS/FluentTM 18.2; os estudos de fabricação dos modelos foram realizados em conjunto com uma empresa de construção de insuflĂĄveis. O desempenho do sistema foi simulado para um coletor e depois para dois coletores, nas condiçÔes de inverno das cidades do Porto e de Fortaleza. O coletor forneceu ĂĄgua quente para uso a temperaturas prĂłximas a 40ÂșC. Foi fabricado um protĂłtipo que Ă© flexĂ­vel e de baixo custo para ser testado o seu desempenho tĂ©rmico.ABSTRACT: These paper reports the development of a flexible and low-cost solar collector and posterior prototype manufacturing, in polyurethane film. Four models of solar collectors were designed in SolidWorksÂź software and simulated in ANSYS/FluentTM 18.2 software; the manufacturing studies of the models were carried out together an inflatable construction company. The systems were simulated for a collector and for two collectors in the winter conditions in the cities of Porto and Fortaleza. The collector provided hot water for use at approximately 40ÂșC. A low-cost and flexible prototype was manufactured and itÂŽs thermal performance will be tested.info:eu-repo/semantics/publishedVersio

    Evidence for the Gompertz Curve in the Income Distribution of Brazil 1978-2005

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    This work presents an empirical study of the evolution of the personal income distribution in Brazil. Yearly samples available from 1978 to 2005 were studied and evidence was found that the complementary cumulative distribution of personal income for 99% of the economically less favorable population is well represented by a Gompertz curve of the form G(x)=exp⁥[exp⁥(A−Bx)]G(x)=\exp [\exp (A-Bx)], where xx is the normalized individual income. The complementary cumulative distribution of the remaining 1% richest part of the population is well represented by a Pareto power law distribution P(x)=ÎČx−αP(x)= \beta x^{-\alpha}. This result means that similarly to other countries, Brazil's income distribution is characterized by a well defined two class system. The parameters AA, BB, α\alpha, ÎČ\beta were determined by a mixture of boundary conditions, normalization and fitting methods for every year in the time span of this study. Since the Gompertz curve is characteristic of growth models, its presence here suggests that these patterns in income distribution could be a consequence of the growth dynamics of the underlying economic system. In addition, we found out that the percentage share of both the Gompertzian and Paretian components relative to the total income shows an approximate cycling pattern with periods of about 4 years and whose maximum and minimum peaks in each component alternate at about every 2 years. This finding suggests that the growth dynamics of Brazil's economic system might possibly follow a Goodwin-type class model dynamics based on the application of the Lotka-Volterra equation to economic growth and cycle.Comment: 22 pages, 15 figures, 4 tables. LaTeX. Accepted for publication in "The European Physical Journal B

    Airway epithelial inflammation-induced endoplasmic reticulum Ca2+ store expansion is mediated by X-box binding protein-1

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    Inflamed cystic fibrosis (CF) human bronchial epithelia (HBE), or normal HBE exposed to supernatant from mucopurulent material (SMM) from CF airways, exhibit endoplasmic reticulum (ER)/Ca2+ store expansion and amplified Ca2-mediated inflammation. HBE inflammation triggers an unfolded protein response (UPR) coupled to mRNA splicing of X-box binding protein-1 (XBP-1). Because spliced XBP-1 (XBP-1s) promotes ER expansion in other cellular models, we hypothesized that XBP-1s is responsible for the ER/Ca2+ store expansion in inflamed HBE. XBP-1s was increased in freshly isolated infected/inflamed CF in comparison with normal HBE. The link between airway epithelial inflammation, XBP-1s, and ER/Ca2+ store expansion was then addressed in murine airways challenged with phosphate-buffered saline or Pseudomonas aeruginosa. P. aeruginosa-challenged mice exhibited airway epithelial ER/Ca2+ store expansion, which correlated with airway inflammation. P. aeruginosa-induced airway inflammation triggered XBP-1s in ER stress-activated indicator (ERAI) mice. To evaluate the functional role of XBP-1s in airway inflammation linked to ER/Ca2+ store expansion, control, XBP-1s, or dominant negative XBP-1 (DN-XBP-1) stably expressing 16HBE14o- cell lines were used. Studies with cells transfected with an unfolded protein response element (UPRE) luciferase reporter plasmid confirmed that the UPRE was activated or inhibited by expression of XBP-1s or DN-XBP-1, respectively. Expression of XBP-1s induced ER/Ca2+ store expansion and potentiated bradykinin-increased interleukin (IL)-8 secretion, whereas expression of DN-XBP-1 inhibited bradykinin-dependent IL-8 secretion. In addition, expression of DN-XBP-1 blunted SMM-induced ER/Ca2+ store expansion and SMM-induced IL-8 secretion. These findings suggest that, in inflamed HBE, XBP-1s is responsible for the ER/Ca2+ store expansion that confers amplification of Ca2+-dependent inflammatory responses

    Local non-Gaussianity from rapidly varying sound speeds

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    We study the effect of non-trivial sound speeds on local-type non-Gaussianity during multiple-field inflation. To this end, we consider a model of multiple-field DBI and use the deltaN formalism to track the super-horizon evolution of perturbations. By adopting a sum separable Hubble parameter we derive analytic expressions for the relevant quantities in the two-field case, valid beyond slow variation. We find that non-trivial sound speeds can, in principle, curve the trajectory in such a way that significant local-type non-Gaussianity is produced. Deviations from slow variation, such as rapidly varying sound speeds, enhance this effect. To illustrate our results we consider two-field inflation in the tip regions of two warped throats and find large local-type non-Gaussianity produced towards the end of the inflationary process.Comment: 30 pages, 7 figures; typos corrected, references added, accepted for publication in JCA
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