Participação escolar: representações dos alunos do 3º ciclo de Aveiro (Portugal)

Este artigo propõe uma reflexão sobre a relação intrínseca entre democracia e educação, particularmente na vertente relacionada com a participação dos discentes nas decisões da escola. Neste sentido e, no quadro do regime de autonomia das escolas portuguesas, importa identificar os espaços formais e informais que são proporcionados aos jovens na tomada de decisões da vida organizativa da escola para compreendermos o papel desta na promoção e capacitação dos jovens para o exercício de uma cidadania ativa. O modo de vida democrático constrói-se através de oportunidades de aprendizagem acerca do mesmo, nomeadamente pela vivência de experiências participativas no contexto escolar. Em 2009, realizámos um estudo, no âmbito da dissertação de uma dissertação de mestrado em Ciências da Educação da Universidade de Aveiro, Portugal, em duas escolas públicas do ensino básico, do Concelho de Aveiro, abrangendo uma população composta por 240 alunos do 8º e 9º ano de escolaridade e 14 delegados de turma. Os resultados mostram que os alunos possuem uma débil participação formal e informal, apesar de o Decreto-lei n. 115-A/98 prever a possibilidade de cada escola, no âmbito da sua autonomia, poder promover e criar espaços de efetiva participação dos alunos. A análise dos instrumentos de autonomia das escolas estudadas revela que a participação dos alunos é assumida, ainda, como um ideal e não já como um efetivo projeto de concretização. Concluímos, pois, que as escolas ainda mantêm uma centralização das decisões nos professores, verificando-se, por parte dos alunos, uma participação formal, passiva e ritualizad

Toll-Like Receptors in Leishmania Infections: Guardians or Promoters?

Protozoa of the genus Leishmania cause a wide variety of pathologies ranging from self-healing skin lesions to visceral damage, depending on the parasite species. The outcome of infection depends on the quality of the adaptive immune response, which is determined by parasite factors and the host genetic background. Innate responses, resulting in the generation of mediators with anti-leishmanial activity, contribute to parasite control and help the development of efficient adaptive responses. Among those, the potential contribution of members of the Toll-like receptors (TLRs) family in the control of Leishmania infections started to be investigated about a decade ago. Although most studies appoint a protective role for TLRs, there is growing evidence that in some cases, TLRs facilitate infection. This review highlights recent advances in TLR function during Leishmania infections and discusses their potential role in restraining parasite growth versus yielding disease

Histologic and Histomorphometric Analysis of Posterior Region of the Human Temporomandibular Disc

Objective The aim of this study was to analyze histologic and histomorphometric features of the articular disc in groups with and without disc displacement. Study design A sample of 39 temporomandibular joints TMJs (31 case specimens, 8 control specimens) from 28 patients (mean age 31.2 years) were recruited for this study. The patients were considered to be affected and treated surgically with disc repositioning when presenting painful clinical signs of disc displacement after unsuccessful nonsurgical treatment for at least 6 months. Of the control patients, 4 presented condyle fracture which required opening to be reduced for treatment, and 4 displayed active condyle hyperplasia. The posterior region of the disc was removed and sent for histologic and histomorphometric analysis. Histologic (hematoxylin-eosin) and histomorphometric (picro-Sirius red) analyses were performed. Statistically significant differences between the analyzed groups were accessed through the chi-squared test (P ≤ .05). The Mann-Whitney U test was used to observe the differences between mean values when variables did not present normal distribution [Kolmogorov-Smirnov(a) test]. Results There were no significant differences between the groups in relation to the parameters studied by histologic and histomorphometric analysis (using or not using polarization). Conclusions To the limits of this study, there were no significant histologic and histomorphometric differences in the articular disc between groups with and without TMJ dysfunction

Potential of supercritical fluid myrtle extracts as an active ingredient and co-preservative for cosmetic and topical pharmaceutical applications

Funding Information: The authors gratefully acknowledge the support of Fundação para a Ciência e a Tecnologia ( FCT ) through the grants UIDB/04567/2020 and UIDP/04567/2020 to CBIOS , UIDB/04028/2020 to CERENA and UIDP/04077/2020 to MEtRICs . Publisher Copyright: © 2022 Elsevier B.V.This study investigated the applications of a myrtle extract obtained by supercritical fluid extraction (SFE), a technique considered environmentally friendly, as a possible antimicrobial ingredient in cosmetic and pharmaceutical formulations. The supercritical fluid extract was obtained at 230 bar and 45 °C, for 2 h, with a flow of CO2 of 0.3 kg h−1. A cosolvent (ethanol) was also used, with a flow 0.09 kg h−1. The extracts thus obtained were tested against seven Gram-positive bacteria and one yeast using the well diffusion and the broth dilution techniques. The results showed that the myrtle extract exhibits good antibacterial activity against all the bacteria strains studied and is superior to most of those obtained by conventional extraction methods. Antifungal activity was also present but at a lesser extent. Cell viability studies were carried out by exposing HaCat cells to a range of extract concentrations, from 0.1 μg/mL up to 60 μg/mL for 24 h, using the MTT assay. The Salmonella mutagenicity assay was applied to evaluate the mutagenicity and antimutagenicity of the extract. The results obtained suggest that the myrtle extract obtained using a green solvent, supercritical CO2, is safe and could reduce the genotoxic damage induced by reactive oxygen species (ROSs).publishersversionpublishe

S-nitrosoglutathione reverts dietary sucrose-induced insulin resistance

The liver is a fundamental organ to ensure whole-body homeostasis, allowing for a proper increase in insulin sensitivity from the fast to the postprandial status. Hepatic regulation of glucose metabolism is crucial and has been shown to be modulated by glutathione (GSH) and nitric oxide (NO). However, knowledge of the metabolic action of GSH and NO in glucose homeostasis remains incomplete. The current study was designed to test the hypothesis that treatment with S-nitrosoglutathione is sufficient to revert insulin resistance induced by a high-sucrose diet. Male Wistar rats were divided in a control or high-sucrose group. Insulin sensitivity was determined: (i) in the fast state; (ii) after a standardized test meal; (iii) after GSH + NO; and after (iv) S-nitrosoglutathione (GSNO) administration. The fasting glucose level was not different between the control and high-sucrose group. In the liver, the high-sucrose model shows increased NO and unchanged GSH levels. In control animals, insulin sensitivity increased after a meal or administration of GSH+NO/GSNO, but this was abrogated by sucrose feeding. GSNO was able to revert insulin resistance induced by sucrose feeding, in a dose-dependent manner, suggesting that they have an insulin-sensitizing effect in vivo. These effects are associated with an increased insulin receptor and Akt phosphorylation in muscle cells. Our findings demonstrate that GSNO promotes insulin sensitivity in a sucrose-induced insulin-resistant animal model and further implicates that this antioxidant molecule may act as a potential pharmacological tool for the treatment of insulin resistance in obesity and type 2 diabetes.publishersversionpublishe

Hybrid magnetic nanoparticles for wet peroxide oxidation of paracetamol

A performance de nanopartículas de ferrite de cobalto, ferrite de cobalto recoberta por carbono preparada por uma metodologia tradicional e ferrite de cobalto preparada por metodologia verde foi avaliada na remoção de paracetamol (PCM), escolhido como poluente modelo, por um processo de oxidação húmida com peróxido de hidrogénio (CWPO). O núcelo magnético foi sintetizado por sol-gel, e na metodologia tradicional de recobrimento de carbono foi considerado resorcinol/formaldeído como precursores de carbono, enquanto que na metodologia verde foi considerado phloroglucinol/ácido glioxílico. Todas as nanopartículas magnéticas (NPMs) apresentaram atividade na remoção de PCM por CWPO. Ambas as NPMs recobertas com carbono apresentaram resultados melhores que o núcleo não recoberto, devido à presença da camada de carbono à volta do núcleo, que também tem atividade pelas propriedades eletrónicas do recobrimento de carbono. O catalisador recoberto pela metodologia verde possui uma decomposição de peróxido de hidrogénio mais controlada. O teste de reutilização do catalisador mostrou a estabilidade do material, com perfis de concentração similares e uma remoção de PCM mais rápida que na primeira utilizaçãoThe performance of non-coated magnetic nanoparticle (MNPs) based on cobalt ferrite (CoFe2O4), and of carbon-coated cobalt ferrite prepared by a traditional method (CoFe2O4@C1), and by a greener method (CoFe2O4@C2) was assessed in the removal of paracetamol (PCM), used as model pharmaceutical pollutant, by catalytic wet peroxide oxidation (CWPO). The magnetic core was synthesized by sol-gel methodology, and the traditional method for carbon coating considered resorcinol and formaldehyde as carbon precursors. In contrast, the greener method was performed considering phloroglucinol and glyoxylic acid as carbon precursors. All MNPs presented activity on the removal of PCM by CWPO. Both carbon-coated MNPs overcome the results obtained with the bare core, due to the carbon layer covering the core, which can also have catalytic activity. The catalyst coated by the greener method (CoFe2O4@C2) shows a more controlled decomposition of hydrogen peroxide. A reutilization test performed to evaluate the stability of this catalyst showed complete removal of PCM faster than in the first usage, with a similar concentration trend profile in both repetitions.Adriano S. Silva thanks his doctoral Grant with reference SFRH/BD/151346/2021 financed by the Portuguese Foundation for Science and Technology (FCT), with funds from NORTE2020, under MIT Portugal Program. Fernanda F. Roman acknowledges the national funding by FCT through the individual research grant SFRH/BD/143224/2019. This work was financially supported by UIDB/00690/2020 (CIMO), LA/P/0045/2020 (ALiCE), UIDB/50020/2020 (LSRE-LCM), and the project RTChip4Theranostics, with the reference NORTE- 01-0145-FEDER-029394. Jose L. Diaz De Tuesta acknowledges the financial support through the program of “Atracción al Talento” of “Comunidad de Madrid” (Spain) for the individual research grant 2020-T2/AMB-19836.info:eu-repo/semantics/publishedVersio

A seção Oráculo: O que perguntam? Como respondem?

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Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNF and IFN

In cutaneous leishmaniasis, Leishmania amazonensis activates macrophage double-stranded, RNA-activated protein kinase R (PKR) to promote parasite growth. In our study, Leishmania major grew normally in RAW cells, RAW-expressing dominant-negative PKR (PKR-DN) cells, and macrophages of PKR-knockout mice, revealing that PKR is dispensable for L. major growth in macrophages. PKR activation in infected macrophages with poly I:C resulted in parasite death. Fifty percent of L. major-knockout lines for the ecotin-like serine peptidase inhibitor (ISP2; Δisp2/isp3), an inhibitor of neutrophil elastase (NE), died in RAW cells or macrophages from 129Sv mice, as a result of PKR activation. Inhibition of PKR or NE or neutralization of Toll-like receptor 4 or 2(TLR4 or TLR2) prevented the death of Δisp2/isp3. Δisp2/isp3 grew normally in RAW-PKR-DN cells or macrophages from 129Sv pkr−/−, tlr2−/−, trif−/−, and myd88−/− mice, associating NE activity, PKR, and TLR responses with parasite death. Δisp2/isp3 increased the expression of mRNA for TNF-α by 2-fold and of interferon β (IFNβ) in a PKR-dependent manner. Antibodies to TNF-α reversed the 95% killing by Δisp2/isp3, whereas they grew normally in macrophages from IFN receptor–knockout mice. We propose that ISP2 prevents the activation of PKR via an NE-TLR4-TLR2 axis to control innate responses that contribute to the killing of L. major.—Faria, M. S., Calegari-Silva, T. C., de Carvalho Vivarini, A., Mottram, J. C., Lopes, U. G., Lima, A. P. C. A. Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNFα and IFNβ

Effect of Iodide-Based Organic Salts and Ionic Liquid Additives in Dye-Sensitized Solar Cell Performance

Funding Information: This work was performed under the project PTDC/QUI-QOR/7450/2020 “Organic Redox Mediators For Energy Conversion” through Fundação para a Ciência e a Tecnologia I. P.-FCT. Additional support includes the Associate Laboratory for Green Chemistry–LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020). FCT/MCTES is also acknowledged for the National NMR Facility (RECI/BBB-BQB/0230/2012 and RECI/BBB-BEP/0124/2012,) and Ph.D. grants 2020.09047.BD (J.S.), PD/BD/135087/2017 (A.L.P.) and PD/BD/145324/2019/ (G.M.). Publisher Copyright: © 2022 by the authors.The use of ionic liquid and organic salts as additives for electrolyte systems in dye-sensitized solar cells have been widely described in recent years. The tunability of their physical-chemical properties according to the cation–anion selection contributes toward their high efficiencies. For this purpose, several iodide-based organic salts including imidazolium, picolinium, guanidinium and alkylammonium cations were tested using acetonitrile/valeronitrile electrolytes and their photovoltaic parameters were compared. A best efficiency of 4.48% (4.15% for the reference) was found for 1-ethyl-2,3-dimethylimidazolium iodide ([C2DMIM]I) containing electrolyte, reaffirming the effectiveness of these additives. 4-tertbutylpyridine was included into the formulation to further improve the performance while determining which iodide salts demonstrate the highest synergy with this additive. [C2DMIM]I once again proved to be the superior additive, achieving an efficiency of 6.48% (6% for the reference). Electrochemical impedance spectroscopy was employed to elucidate the effects of the various additives, demonstrating the relevance of the counter electrode resistance on device performance. Finally, several computational descriptors for the cationic structures were calculated and correlated with the photovoltaic and resistance parameters, showing that properties related to polarity, namely relative positive charge, molecular polarizability and partition coefficient are in good agreement with the counter-electrode resistance.publishersversionpublishe