Rutin-functionalized multi-walled carbon nanotubes: molecular docking, physicochemistry and cytotoxicity in fibroblasts

Multi-Walled Carbon Nanotubes (MWCNT) have been functionalized with rutin through three steps (i. reaction step; ii. purification step; iii. drying step) and their physicochemical properties investigated with respect to morphological structure, thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR), and cytotoxicity. The molecular docking suggested the rutin-functionalized MWCNT occurred by hydrogen bonds, which was confirmed by FTIR assays, corroborating the results obtained by thermal analyses. A tubular shape, arranged in a three-dimensional structure, could be observed. Mild cytotoxicity observed in 3T3 fibroblasts suggested a doseeffect relationship after exposure. These findings suggest the formation of aggregates of filamentous structures on the cells favoring the cell penetration.The authors acknowledge Classius Ferreira da Silva, from the Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, for the scanning electron microscopy analyses.info:eu-repo/semantics/publishedVersio

Metal-enriched nanoparticles and black carbon: A perspective from the Brazil railway system air pollution

Having a better understanding of air pollutants in railway systems is crucial to ensure a clean public transport. This study measured, for the first time in Brazil, nanoparticles (NPs) and black carbon (BC) on two ground-level platforms and inside trains of the Metropolitan Area of Porto Alegre (MAPA). An intense sampling campaign during thirteen consecutive months was carried out and the chemical composition of NPs was examined by advanced microscopy techniques. The results showed that highest concentrations of the pollutants occur in colder seasons and influenced by variables such as frequency of the trains and passenger densities. Also, internal and external sources of pollution at the stations were identified. The predominance of NPs enriched with metals that increase oxidative stress like Cd, Fe, Pb, Cr, Zn, Ni, V, Hg, Sn, and Ba both on the platforms and inside trains, including Fe-minerals as hematite and magnetite, represents a critical risk to the health of passengers and employees of the system. This interdisciplinary and multi-analytical study aims to provide an improved understanding of reported adverse health effects induced by railway system aerosols

Temporal Changes in Technical and Physical Performances During a Small-Sided Game in Elite Youth Soccer Players

Background: There have been claims that small-sided games (SSG) may generate an appropriate environment to develop youth players’ technical performance associated to game-related problem solving. However, the temporal change in technical performance parameters of youth players during SSG is still unknown.. Objectives: The aim of this study was to examine temporal changes in technical and physical performances during a small-sided game (SSG) in elite soccer players.. Methods: Sixty elite youth players (age 14.8 ± 0.2 yr; stature 177 ± 5 cm; body mass 66.2 ± 4.7 kg) completed a 5 v 5 SSG using two repetitions of 8 minutes interspersed by 3 minutes of passive recovery. To evaluate temporal changes in performance, the data were analysed across 4 minutes quarters. Physical performance parameters included the total distance covered (TDC), the frequency of sprints (>18 km•h-1), accelerations and decelerations (> 2.0 m•s-2 and - 2.0 m•s-2), metabolic power (W•kg-1), training impulse (TRIMP), TDC: TRIMP, number of impacts, and body load. Technical performance parameters included goal attempts, total number of tackles, tackles and interceptions, total number of passes, and passes effectiveness.. Results: All physical performance parameters decreased from the first to the last quarter with notable declines in TDC, metabolic power and the frequency of sprints, accelerations and decelerations (P 0.05; trivial ES for 1st v 4th quarters: 0.15 - 0.33).. Conclusions: The data demonstrate that technical performance is maintained despite substantial declines in physical performance during a SSG in elite youth players. This finding may have implications for designing SSG’s for elite youth players to ensure physical, technical and tactical capabilities are optimized. Modifications in player number, pitch dimensions, rules, coach encouragement, for instance, should be included taking into account the main aim of a given session and then focused on overloading physical or technical elements.

Teaching Sciences in Virtual Worlds with Mastery Learning: A Case of Study in Elementary School

Virtual worlds are 3D environments that provide a feeling of immersion and a high degree of interaction, collaboration, communication between users. Its applicability can be focused on the educational scope, in which theories can be integrated as the basis to didactic activities carried out in the 3D environment, being its area of interdisciplinary comprehension. In this context, this article presents the use of a Virtual World built to assist in the teaching of Science for students of the middle school, whose articulation of the activities performed in the course are based on the precepts of the educational theory Mastery Learning. Tests were carried out in the subject of science, being divided into two periods with different groups for comparative purposes and realized evaluations during the period of the experiments. Kruskal-Wallis and Wilcoxon-Mann-Whitney non-parametric test were applied to the results of the assessments to ascertain the performance of each group. It was verified in the general analyzis that the participants who used the Virtual World had a growing performance, with high medians and adequate distribution of the results, being predominant of a smaller variability and amplitude. Thus, was possible to conclude that the results obtained with the approach were positive, which led to the validation of this research and presented a clear contribution to the academic environment

A reflexão como um instrumento de formação no PFCM

O Programa de Formação Contínua em Matemática para Professores dos 1.º e 2.º Ciclos do Ensino Básico (PFCM), com o objectivo de melhorar o ensino e as aprendizagens em Matemática e desenvolver atitudes mais positivas face a esta área do saber, pretende responder às necessidades dos professores participantes, partindo de questões relativas à concretização do currículo de Matemática na sala de aula e tendo um carácter continuado ao longo do ano lectivo. O PFCM constitui, assim, um instrumento de apoio e ajuda aos professores participantes na sua prática lectiva (planificação do trabalho, condução da aula, reflexão sobre o que foi feito) de modo a melhorar as suas actuações profissionais e, consequentemente, as aprendizagens matemáticas dos seus alunos. No anterior ano lectivo, o plano de formação desenvolvido pela Escola Superior de Educação de Bragança (ESEB), embora possibilitasse a abordagem de qualquer conteúdo de formação previsto, centrou-se em alguns domínios, nomeadamente, na clarificação ou aprofundamento de temas matemáticos, na discussão dos tipos e natureza das tarefas (exercícios, explorações, problemas, investigações; jogos, projectos), em aspectos da comunicação matemática, na utilização de materiais curriculares, e na construção dos portefólios, valorizando os registos escritos e reflexão. Nesta comunicação pretendemos discutir, com base na observação participante e na análise documental, situações e episódios ocorridos nas salas de aula que fundamentem aspectos do ensino e aprendizagem da Matemática destacados pelo plano de formação da ESEB e evidenciados quer pelos formadores quer pelos professores participantes, dando especial relevância à reflexão (pessoal e partilhada) sobre as experiências profissionais