Search

In this work, the corrosion behavior of the AA4006 alloy made by the twin roll caster process was evaluated using electrochemical impedance spectroscopy (EIS), anodic potentiodynamic polarization curves, and scanning electron microscopy (SEM). This alloy belongs to the Al-Fe-Si system and is present with higher amounts of Fe and Si than AA1050 aluminum. Electrochemical tests were performed in a sulfate solution with or without chloride ions, and two different areas of the AA4006 alloy were tested: at the surface and at the center of the sheet (half thickness). The results obtained were compared to the commercially pure AA1050 aluminum. Electrochemical tests carried out using the solution without chloride ions presented similar results; however, the addition of chloride ions resulted in localized corrosion in all samples. It was possible to compare the corrosion behavior of the studied materials analyzing these electrochemical data and the micrographs obtained by scanning electron microscopy. [ABSTRACT FROM AUTHOR]

This work presents the effects of a cerium conversion coating, self-assembling molecules (SAM) treatment, and a combination of these two treatments on the corrosion resistance of the AA3003 alloy. The results were compared to that of a conversion coating treatment with hexavalent chromium (Cr VI). The corrosion resistance of the surface-treated AA3003 alloy samples was investigated by electrochemical impedance spectroscopy and anodic polarization curves in 0.5 mol/L sodium sulfate solution with pH adjusted to 4.0. The results showed that the SAM treatment offered better corrosion protection for the AA3003 alloy than that provided by cerium conversion coating. The combination of cerium conversion and SAM treatments improved the corrosion resistance of the AA3003 alloy due to SAM adsorption on the alloy substrate exposed at the defects in the cerium conversion layer. [ABSTRACT FROM AUTHOR]

β-Glucosidases (BGLs) belong to the group of enzymes of cellulases and act in the last stage of cellulose degradation, releasing glucose molecules, eliminating the inhibitory effect of cellobiose. This study focused on the production, characterization, and application of BGL from Moniliophthora perniciosa in the hydrolysis of pretreated sugarcane bagasse (3% NaOH + 6% Na 2 SO 3 ), with varying enzymatic loads and reaction times. The enzyme showed an optimum pH of 4.5 and 60°C. It was stable at all temperatures analyzed (50-90°C) and retained about 100% of its activity at 50°C after 60 min of incubation. Among the ions analyzed, BaCl 2 increased BGL activity 9.04 ± 1.41 times. The maximum production of reducing sugars (89.15%) was achieved after 48 h with 10 mg of protein., (© 2021 International Union of Biochemistry and Molecular Biology, Inc.)

Objectives: Changes in the joints are believed to result from "wear and tear," a consequence of activity, as entheseal changes (EC) result from muscle use. However, clinical data showed that activity does not necessarily increase the likelihood of degenerative joint changes (DJC) and that exercise results in healthier joints. We tested whether individuals with continuous repetitive biomechanical efforts (Group 1) were more likely to exhibit EC and if occupations known to exert strenuous but discontinued efforts (Group 2) would more likely cause DJC., Materials and Methods: Eighty-nine males with known occupations from Portuguese identified collections were used: shoemakers and carpenters (Group 1), workers (Group 2), and civil servants, and shop assistants as a control group. Major upper and lower limb joints and entheses sites were used. DJC and EC were tested between occupations - while controlling for age (overall approach) - and within occupation (occupation-specific approach)., Results: The overall approach showed that age - as a covariant - had a significant impact on DJC and EC development (p < 0.05), with occupation being non-significant (p > 0.05) despite the variability in the mean-values of lesions. The occupation-specific approach showed a significant variability of DJC and EC correlations, within and between occupations, with no clear trend of DJC and EC development according to occupation., Discussion: The results showed that exploring overall patterns might conceal occupation-specific joint and muscle use, emphasizing age as a major contributor of changes; and that the occupation-specific approach highlighted particular aspects associated with occupations, allowing for a more informative assessment of strenuous repetitive or discontinuous activity-related technical gestures and their impact on skeletal biology., (© 2021 Wiley Periodicals LLC.)

Analyses of entheseal changes (EC) in identified skeletal samples employ a common research strategy based on the comparison between occupations grouped on the basis of shared biomechanical and/or social characteristics. Results from this approach are often ambiguous, with some studies that point to differences in EC between occupational samples and others failing to provide evidence of behavioral effects on EC. Here we investigate patterns of EC among documented occupations by means of a multivariate analysis of robusticity scores in nine postcranial entheses from a large (N = 372) contemporary skeletal sample including specimens from one Italian and two Portuguese identified collections. Data on entheseal robusticity, analyzed by pooled sides as well by separated sides and levels of asymmetry, are converted in binary scores and then analyzed through nonlinear principal component analysis and hierarchical cluster analysis. Results of these analyses are then used for the classification of occupations. Differences between occupational classes are tested by MANOVA and pairwise Hotelling's test. Results evidence three classes which separate occupations related to farming, physically demanding but generalized occupation, and physically undemanding occupations, with the more consistent differences between the first and the last classes. Our results are consistent with differences in biomechanical behavior between the occupations included in each class, and point to the physical and social specificity of farming activities. On the other hand, our study exemplifies the usefulness of alternative analytical protocols for the investigation of EC, and the value of research designs devoid of a priori assumptions for the test of biocultural hypotheses., (Copyright © 2014 Wiley Periodicals, Inc.)

Background: Helicobacter pylori infection is a strong risk factor for gastric cancer, likely due to the extensive inflammation in the stomach mucosa caused by these bacteria. Many studies have reported an association between IL10 polymorphisms, the risk of gastric cancer, and IL-10 production. The aim of the study was to evaluate the association between IL10 genetic variants, Helicobacter pylori infection, and IL-10 production by peripheral blood leukocytes in children., Materials and Methods: We genotyped a total of 12 single nucleotide polymorphisms in IL10 in 1259 children aged 4-11 years living in a poor urban area in Salvador, Brazil, using TaqMan probe based, 5' nuclease assay minor groove binder chemistry. Association tests were performed by logistic regression for Helicobacter pylori infection and linear regression for IL-10 spontaneous production (whole-blood cultures) including sex, age, and principal components for informative ancestry markers as covariates, using PLINK., Results: Our results shown that IL10 single nucleotide polymorphisms rs1800896 (OR = 1.63; 95% CI = 1.11-2.39), rs3024491 (OR = 1.71; 95% CI = 1.14-2.57), rs1878672 (OR = 1.79; 95% CI = 1.19-2.68), and rs3024496 (OR = 1.48; 95% CI = 1.05-2.08) were positively associated with Helicobacter pylori infection. Eight single nucleotide polymorphisms were associated with spontaneous production of IL-10 in culture, of which three (rs1800896 and rs1878672, p = .04; rs3024491, p = .01) were strongly associated with infection by Helicobacter pylori., Conclusions: Our results indicate that IL10 variants rs1800896, rs3024491, rs1878672, and rs3024496 are more consistently associated with the presence of anti-H. pylori IgG by inducing increased production of IL-10. Further studies are underway to elucidate the role of additional genetic variants and to investigate their impact on the occurrence of gastric cancer., (© 2014 John Wiley & Sons Ltd.)