36 research outputs found

    A review of Corrosion Resistance Nanocomposite Coatings

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    The deterioration of materials, particularly metals, under the influence of electrochemical corrosion is a high cost problem faced by nearly all industries. The reduction of corrosion processes and the prevention of future problems require a detailed knowledge of these processes and of the strategies to avoid them. In this context, it is essential to use methodologies that may prevent the electrochemical deterioration of materials as well as monitor their performance in aggressive environments. Among them, it is possible to cite the use of functional coatings, particularly nanocomposite coatings. Therefore, this chapter proposes a review concerning the production of nanocomposite coatings with anticorrosive application obtained by electrodeposition technique (electrochemical codeposition). The production of such coatings is in agreement with the current needs of innovation, which drives a requirement for scientific advancement and the need for fundamental research. In this context, nanocomposite coatings with anticorrosive properties promote changes in metal surfaces, creating new materials with improved characteristics compared to those originally observed and maintaining the integrity of these surfaces

    Equations based on anthropometric measurements for adipose tissue, body fat, or body density prediction in children and adolescents: a scoping review

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    Assessing the body composition of children and adolescents is important to monitor their health status. Anthropometric measurements are feasible and less-expensive than other techniques for body composition assessment. This study aimed to systematically map anthropometric equations to predict adipose tissue, body fat, or density in children and adolescents, and to analyze methodological aspects of the development of anthropometric equations using skinfolds. Methods: A scoping review was carried out following the PRISMA-ScR criteria. The search was carried out in eight databases. The methodological structure protocol of this scoping review was retrospectively registered in the Open Science Framework (https://osf.io/35uhc/). Results: We included 78 reports and 593 anthropometric equations. The samples consisted of healthy individuals, people with different diseases or disabilities, and athletes from different sports. Dual-energy X-ray absorptiometry (DXA) was the reference method most commonly used in developing equations. Triceps and subscapular skinfolds were the anthropometric measurements most frequently used as predictors in the equations. Age, stage of sexual maturation, and peak height velocity were used as complementary variables in the equations. Conclusion: Our scoping review identified equations proposed for children and adolescents with a great diversity of characteristics. In many of the reports, important methodological aspects were not addressed, a factor that may be associated with equation bias. Level IV: Evidence obtained from multiple time series analysis such as case studies. (NB: dramatic results in uncontrolled trials might also be regarded as this type of evidence).info:eu-repo/semantics/publishedVersio

    Comparison of different protocols for the extraction of microbial DNA from reef corals

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    This study aimed to test different protocols for the extraction of microbial DNA from the coral Mussismilia harttii. Four different commercial kits were tested, three of them based on methods for DNA extraction from soil (FastDNA SPIN Kit for soil, MP Bio, PowerSoil DNA Isolation Kit, MoBio, and ZR Soil Microbe DNA Kit, Zymo Research) and one kit for DNA extraction from plants (UltraClean Plant DNA Isolation Kit, MoBio). Five polyps of the same colony of M. harttii were macerated and aliquots were submitted to DNA extraction by the different kits. After extraction, the DNA was quantified and PCR-DGGE was used to study the molecular fingerprint of Bacteria and Eukarya. Among the four kits tested, the ZR Soil Microbe DNA Kit was the most efficient with respect to the amount of DNA extracted, yielding about three times more DNA than the other kits. Also, we observed a higher number and intensities of DGGE bands for both Bacteria and Eukarya with the same kit. Considering these results, we suggested that the ZR Soil Microbe DNA Kit is the best adapted for the study of the microbial communities of corals
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