58 resultados para oscar vilhena vieira


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Nutrients composition, phenolic compounds, antioxidant activity and estimated glycemic index (EGI) were evaluated in sorghum bran (SB) and decorticated sorghum flour (DSF), obtained by a rice-polisher, as well as whole sorghum flour (WSF). Correlation between EGI and the studied parameters were determined. SB presented the highest protein, lipid, ash, β-glucan, total and insoluble dietary fiber contents; and the lowest non-resistant and total starch contents. The highest carbohydrate and resistant starch contents were in DSF and WSF, respectively. Phenolic compounds and antioxidant activities were concentrated in SB. The EGI values were: DSF 84.5±0.41; WSF 77.2±0.33; and SB 60.3±0.78. Phenolic compounds, specific flavonoids and antioxidant activities, as well as total, insoluble and soluble dietary fiber and β-glucans of sorghum flour samples were all negatively correlated to EGI. RS content was not correlated to EGI.

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To identify the prevalence and the severity of malocclusions and to analyze factors associated with the need for orthodontic treatment of Brazilian adolescents. This exploratory, cross-sectional study was carried out based on secondary data from the national epidemiological survey on oral health in Brazil (2002-2003). Socio-demographic conditions, self-perception, and the existence and degree of malocclusion, using the Dental Aesthetic Index, were evaluated in 16,833 adolescent Brazilians selected by probabilistic sample by conglomerates. The dependent variable - need orthodontic treatment - was estimated from the severity of malocclusion. The magnitude and direction of the association in bivariate and multivariate analyzes from a Robust Poisson regression was estimated RESULTS: The majority of the adolescents needed orthodontic treatment (53.2%). In the multivariate analysis, the prevalence of the need for orthodontic treatment was larger among females, non-whites, those that perceived a need for treatment, and those that perceived their appearance as normal, bad, or very bad. The need for orthodontic treatment was smaller among those that lived in the Northeast and Central West macro-regions compared to those living in Southeast Brazil and it was also smaller among those that perceived their chewing to be normal or their oral health to be bad or very bad. There was a high prevalence of orthodontic treatment need among adolescents in Brazil and this need was associated with demographic and subjective issues. The high prevalence of orthodontic needs in adolescents is a challenge to the goals of Brazil's universal public health system.

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Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

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In recent years, the scientific community has undertaken research on plant extracts, searching for compounds with pharmacological activities that can be used in diverse fields of medicine. Calendula officinalis L. is known to have antioxidant, anti-inflammatory, antibacterial, and wound healing properties when used to treat skin burns. Therefore, the purpose of this study was to analyze the effects of C. officinalis on the initial phase of Achilles tendon healing. Wistar rats were separated in three groups: Calendula (Cal)-rats with a transected tendon were treated with topical applications of C. officinalis cream and then euthanized 7 days after injury; Control (C)-rats were treated with only vehicle after transection; and Normal (N)-rats without tenotomy. Higher concentrations of hydroxyproline (an indicator of total collagen) and non-collagenous proteins were observed in the Cal group in relation to the C group. Zymography showed no difference in the amount of the isoforms of metalloproteinase-2 and of metalloproteinase-9, between C and Cal groups. Polarization microscopy images analysis showed that the Cal group presented a slightly higher birefringence compared with the C group. In sections of tendons stained with toluidine blue, the transected groups presented higher metachromasy as compared with the N group. Immunocytochemistry analysis for chondroitin-6-sulfate showed no difference between the C and Cal groups. In conclusion, the topical application of C. officinalis after tendon transection increases the concentrations of collagen and non-collagenous proteins, as well as the collagen organization in the initial phase of healing.

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The 22q11 chromosomal region contains low copy repeats (LCRs) sequences that mediate non-allelic homologous recombination, which predisposes to copy number variations (CNVs) at this locus. Hemizygous deletions of the proximal 22q11.2 region result in the 22q11.2 deletion syndrome (22q11.2 DS). In addition, 22q11.2 duplications involving the distal LCR22s have been reported. This article describes a patient presenting a 2.5-Mb de novo deletion at proximal 22q11.21 region (between LCRs A-D), combined with a 1.3-Mb maternally inherited duplication at distal 22q11.23 region (between LCRs F-H). The presence of concomitant chromosomal imbalances found in this patient has not been reported previously. Clinical and molecular data were compared with literature, in order to contribute to genotype-phenotype correlation. These findings exemplify the complexity and genetic heterogeneity observed in 22q11.2 deletion syndrome and highlights the difficulty to make genetic counseling and predict phenotypic consequences in these situations.

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Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.

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Vasodilator-stimulated phosphoprotein (VASP) and Zyxin are interacting proteins involved in cellular adhesion and motility. PKA phosphorylates VASP at serine 157, regulating VASP cellular functions. VASP interacts with ABL and is a substrate of the BCR-ABL oncoprotein. The presence of BCR-ABL protein drives oncogenesis in patients with chronic myeloid leukemia (CML) due to a constitutive activation of tyrosine kinase activity. However, the function of VASP and Zyxin in BCR-ABL pathway and the role of VASP in CML cells remain unknown. In vitro experiments using K562 cells showed the involvement of VASP in BCR-ABL signaling. VASP and Zyxin inhibition decreased the expression of anti-apoptotic proteins, BCL2 and BCL-XL. Imatinib induced an increase in phosphorylation at Ser157 of VASP and decreased VASP and BCR-ABL interaction. VASP did not interact with Zyxin in K562 cells; however, after Imatinib treatment, this interaction was restored. Corroborating our data, we demonstrated the absence of phosphorylation at Ser157 in VASP in the bone marrow of CML patients, in contrast to healthy donors. Phosphorylation of VASP on Ser157 was restored in Imatinib responsive patients though not in the resistant patients. Therefore, we herein identified a possible role of VASP in CML pathogenesis, through the regulation of BCR-ABL effector proteins or the absence of phosphorylation at Ser157 in VASP.

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This study focus on the reconfiguration of educational management in Argentina, Brazil, Chile and Mexico, which was promoted by the new logic of social regulation and the new role attributed to the State, considering each country's own historicity. So, the cultural factors that interfere on the dynamics of the 90' school reform are analyzed. Aspects that show the homogeneity or heterogeneity of these reforms in the region, as well as local specificities that block out the concretization of the reform are underlined. It is shown that the historicity that characterizes the educational reform has taken, in each country, a form that can be called, in Mexico, conservative rupture; in Chile, conservative continuity; in Brazil, conservative renovation; and, in Argentina, interrupted rupture. Some conclusions about the impact of educational reform in the selected countries are recuperated through the analysis of 186 academic texts on the subject.

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The caffeine solubility in supercritical CO2 was studied by assessing the effects of pressure and temperature on the extraction of green coffee oil (GCO). The Peng-Robinson¹ equation of state was used to correlate the solubility of caffeine with a thermodynamic model and two mixing rules were evaluated: the classical mixing rule of van der Waals with two adjustable parameters (PR-VDW) and a density dependent one, proposed by Mohamed and Holder² with two (PR-MH, two parameters adjusted to the attractive term) and three (PR-MH3 two parameters adjusted to the attractive and one to the repulsive term) adjustable parameters. The best results were obtained with the mixing rule of Mohamed and Holder² with three parameters.

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The main objective of this paper is to start and stimulate reflection, discussion and proposing actions that allow Chemistry in Brazil contribute to a prosperous, safer and better future for the nation.

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The effects of ionic strength on ions in aqueous solutions are quite relevant, especially for biochemical systems, in which proteins and amino acids are involved. The teaching of this topic and more specifically, the Debye-Hückel limiting law, is central in chemistry undergraduate courses. In this work, we present a description of an experimental procedure based on the color change of aqueous solutions of bromocresol green (BCG), driven by addition of electrolyte. The contribution of charge product (z+|z-|) to the Debye-Hückel limiting law is demonstrated when the effects of NaCl and Na2SO4 on the color of BCG solutions are compared.

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Sugarcane holds an important place in the Brazilian economy. Grate part of the sugarcane harvested still accomplished largely manually. Sugarcane harvesters available in Brazil use the technology to chop the cane into 200 to 300 mm billets to allow on the go cane transferring to transport, contradicting the traditional method of whole stalk sugarcane harvesting system. In order to make whole stalk mechanical harvesting system possible, one of the barriers to be expired is the mechanical removal of the straw. The design of a mechanism that accomplishes this operation depends directly on the knowledge of the mechanical properties of the sugarcane related to its resistance to compression and the forces necessary to remove the leaves from the stalk. Compression tests were conducted using the universal testing machine. For leaves removal test by friction, a special apparatus was designed to allow the registration of the normal and traction force. The sugarcane stalk can resist up to 4.9 MPa. With a normal pressure of 0.8 MPa, which correspond to a friction force of 315 N, it is possible to remove the leaves, independent of its location in the sugarcane stalk.

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The physical model was based on the method of Newton-Euler. The model was developed by using the scientific computer program Mathematica®. Several simulations where tried varying the progress speeds (0.69; 1.12; 1.48; 1.82 and 2.12 m s-1); soil profiles (sinoidal, ascending and descending ramp) and height of the profile (0.025 and 0.05 m) to obtain the normal force of soil reaction. After the initial simulations, the mechanism was optimized using the scientific computer program Matlab® having as criterion (function-objective) the minimization of the normal force of reaction of the profile (FN). The project variables were the lengths of the bars (L1y, L2, l3 and L4), height of the operation (L7), the initial length of the spring (Lmo) and the elastic constant of the spring (k t). The lack of robustness of the mechanism in relation to the variable height of the operation was outlined by using a spring with low rigidity and large length. The results demonstrated that the mechanism optimized showed better flotation performance in relation to the initial mechanism.

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A base-cutter represented for a mechanism of four bars, was developed using the Autocad program. The normal force of reaction of the profile in the contact point was determined through the dynamic analysis. The equations of dynamic balance were based on the laws of Newton-Euler. The linkage was subject to an optimization technique that considered the peak value of soil reaction force as the objective function to be minimized while the link lengths and the spring constant varied through a specified range. The Algorithm of Sequential Quadratic Programming-SQP was implemented of the program computational Matlab. Results were very encouraging; the maximum value of the normal reaction force was reduced from 4,250.33 to 237.13 N, making the floating process much less disturbing to the soil and the sugarcane rate. Later, others variables had been incorporated the mechanism optimized and new otimization process was implemented .

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Base cutting and feeding into harvesters of plants lying close to the ground surface require an efficient sweeping action of the cutting mechanism. It is not the case of conventional sugarcane harvesters which have rigid blades mounted on discs capable to contaminate the cane with dirt as well as damage the ratoons. The objective of this work was to simulate the sweeping performance of a segmented base cutter. The model was developed using the laws of dynamic. Simulation included two rotational speeds (400 and 600 rpm), two cutting heights (0.12 and 0.13 m) and two disk tilting angles (-10º and -12º). The simulated sweeping angle varied between 56º and 193º, which are very promising as a mean to cutting and feeding cane sticks lying on the ground. Cutting height was the variable that affected sweeping action the most. This behavior indicates the need to have an automatic control of the cutting disk height in order to keep good sweeping performance as the harvester moves forward.