Zur kariesprotektiven Wirkung einer Zahnpaste mit bioaktivem Glas im Vergleich zu Zahnpasten mit unterschiedlichen Fluoridverbindungen

Problemstellung: Karies als eine lokalisierte, multifaktoriell bedingte Erkrankung beginnt mit einer kariösen Initialläsion. Um einer Progression dieser Initialläsion entgegenzuwirken, gibt es unter anderem verschiedene Zahnpasten auf dem Markt mit kariesprotektiver Wirkung. Eine 2016 auf dem Markt erschienene Zahnpaste mit bioaktivem Glas und Natriumfluorid verspricht durch das bioaktive Glas an der Zahnoberfläche zu binden und Calcium, Phosphat und Fluoridionen über einen längeren Zeitraum freizusetzen. Dies soll zu einem verbesserten Remineralisationseffekt führen. Ziel: In der vorliegenden Arbeit wurde das Remineralisationsverhalten der Zahnpaste mit bioaktivem Glas und Natriumfluorid im Vergleich zu Zahnpasten mit den unterschiedlichen Fluoridverbindungen Natriumfluorid und Zinnfluorid in-vitro untersucht. Es sollte ermittelt werden, ob Unterschiede im remineralisierenden Effekt der Zahnpaste mit bioaktivem Glas und Natriumfluorid und der Vergleichszahnpasten bestehen. Dabei bezog sich eine Hypothese auf den Vergleich des remineralisierenden Effektes der Zahnpaste mit bioaktivem Glas und Natriumfluorid und der Zahnpaste mit Natriumfluorid anhand des Fluoreszenzverlustes (∆F) und des Volumens der Läsion (∆Q). Die andere Hypothese bezog sich auf den Vergleich des remineralisierenden Effektes der Zahnpaste mit bioaktivem Glas und Natriumfluorid und der Zahnpaste mit Zinnfluorid anhand des Fluoreszenzverlustes (∆F) und des Volumens der Läsion (∆Q). Material und Methoden: Für die Studie wurden 45 Zahnproben von extrahierten humanen Zähnen verwendet. An allen Proben (n = 45) wurde eine zu beurteilende Fläche poliert, je 15 Proben wurden randomisiert drei Gruppen (Testgruppe, Kontrollgruppe I, Kontrollgruppe II) zugeteilt und mittels eines Methylcellulose-Milchsäure-Systems (pH = 4,6) für 14 Tage artifiziell demineralisiert. Für jede Gruppe wurde eine Zahnpaste mit unterschiedlicher Fluoridverbindung ausgewählt: Testgruppe = BioMinTM F (bioaktives Glas und 530 ppm Natriumfluorid), Kontrollgruppe I = Signal Kariesschutz (1450 ppm Natriumfluorid) und Kontrollgruppe II = Sensodyne Repair*&Protect (1100 ppm Zinnfluorid). Über einen Zeitraum von 90 Tagen wurden die Proben in einer Remineralisationslösung bei 37 °C im Brutschrank gelagert. Dabei wurden alle Proben im Sinne eines pH-Cycling-Modells behandelt, um die Phasen der Demineralisation und Remineralisation zu simulieren. Dafür wurden sie zweimal täglich zwei Minuten in 0,1 M Milchsäure (pH = 4,6) eingelegt, mit destilliertem Wasser abgespült und anschließend für zwei Minuten in eine Zahnpastensuspension der jeweiligen Zahnpaste eingelegt. Mittels quantitativer lichtinduzierter Fluoreszenz (QLFTM) wurden Messungen vor und nach der Demineralisation und nach 7, 30, 60 und 90 Tagen durchgeführt. Beurteilt wurde das Mineralisationsverhalten anhand der Kenngrößen des Fluoreszenzverlustes (∆F in %) und des Volumens der Läsion (∆Q in % x px2). Die anschließende statistische Auswertung erfolgte mit der Software MedCalc, Version 19.3.1. Die Messergebnisse wurden mittels des Shapiro-Wilk-Tests auf Normalverteilung untersucht (p < 0,001). Für die Untersuchung der unabhängigen Daten wurde der Kruskal-Wallis-Test, für die abhängigen Daten der Friedman-Test und weiterführend die Post-hoc-Analyse nach Conover durchgeführt. Das Signifikanzniveau wurde auf α = 0,05 festgelegt. Ergebnisse: Nach 7 Tagen konnten sowohl für den Fluoreszenzverlust ∆F in % (p = 0,019) als auch für das Volumen der Läsion ∆Q in % x px2 (p = 0,011) signifikante Unterschiede festgestellt werden. Für beide Parameter wies die Testgruppe (bioaktives Glas und Natriumfluorid) nach 7 Tagen eine geringere remineralisierende Wirksamkeit im Vergleich zu beiden Kontrollgruppen auf. Nach 90 Tagen wurde für ∆F ein signifikanter Unterschied im remineralisierenden Effekt festgestellt (p = 0,041). Demnach wies die Testgruppe (bioaktives Glas und Natriumfluorid) einen größeren Fluoreszenzverlust und damit einen geringeren remineralisierenden Effekt auf als die Kontrollgruppe II (Zinnfluorid). Diskussion und Schlussfolgerung: Die Ergebnisse dieser in-vitro-Studie zeigen, dass zum Zeitpunkt nach 7 Tagen die Testzahnpaste und beide Vergleichszahnpasten, sowie über einen Zeitraum von 90 Tagen die Testzahnpaste und die Vergleichszahnpaste mit Zinnfluorid nicht über eine gleiche remineralisierende Wirksamkeit verfügen. Die Vergleichszahnpaste mit Zinnfluorid zeigte bezüglich des Parameters ∆F die höchste remineralisierende Wirkung. Weitere Studien sind nötig, um die in dieser Studie erzielten Ergebnisse in-vivo zu überprüfen

The effect of using mixed initiator systems on the efficiency of photopolymerization of dental resins

A study was performed in order to determine the efficiency of the simultaneous use of the photoinitiators phenylpropanedione (PPD) and camphorquinone (CQ) in the polymerization of acrylic polymers and evaluate possible mechanisms leading to synergism or antagonism. It was found that efficiencies of both initiators taken individually are higher than that of their mixture, indicating that when both dyes are used simultaneously there will be an energy transfer from the more efficient initiator (CQ) to the less efficient one (PPD). Also, there was no proof of any reaction between the amine present in the CQ formulation and the PPD excited state.Foi realizado um estudo para determinar a eficiência da utilização simultânea dos fotoiniciadores fenilpropanodiona (PPD) e canforquinona (CQ) para a polimerização de polímeros acrílicos e avaliar possíveis mecanismos que levem à sinergia ou antagonismo. Foi encontrado que as eficiências de ambos iniciadores usados individualmente são maiores que a da mistura, indicando que quando os iniciadores são usados simultaneamente há uma transferência de energia do iniciador mais eficiente (CQ) para o menos eficiente (PPD). Também, não foi encontrada nenhuma evidência de reação entre a amina presente na formulação da CQ e o PPD no estado excitado.FAPESPCNP

The UV/H2O2 - photodegradation of poly(ethyleneglycol) and model compounds

The general mechanism for the photodegradation of polyethyleneglycol (PEG) by H2O2/UV was determined studying the photooxidation of small model molecules, like low molecular weight ethyleneglycols (tetra-, tri-, di-, and ethyleneglycol). After 30 min of irradiation the average molar mass (Mw) of the degradated PEG, analysed by GPC, fall to half of its initial value, with a concomitant increase in polydispersitivity and number of average chain scission (S), characterizing a random chain scission process yielding oligomers and smaller size ethyleneglycols. HPLC analysis of the photodegradation of the model ethyleneglycols proved that the oxidation mechanism involved consecutive reactions, where the larger ethyleneglycols gave rise, successively, to smaller ones. The photodegradation of ethyleneglycol lead to the formation of low molecular weight carboxylic acids, like glycolic, oxalic and formic acids.O mecanismo geral para a fotodegradação do polietilenoglicol (PEG) usando o sistema H2O2/UV foi determinado por GPC e HPLC, analisando o comportamento de moléculas modelo, como por exemplo os etilenoglicóis de baixa massa molar (tetra-, tri-, di-, e etilenoglicol). Após 30 min de irradiação, a massa molar ponderal média (Mw) do PEG degradado, analisada por GPC, cai para metade do seu valor inicial com um aumento concomitante na polidispersidade e número médio de quebra de cadeia (S). Essa queda acentuada caracteriza uma quebra de cadeia aleatória, formando oligômeros e etilenoglicóis de menor massa molar. A análise da fotodegradação de etilenoglicóis modelo por HPLC permitiu sugerir um mecanismo que envolve processos consecutivos, em que etilenoglicóis maiores originam menores, sucessivamente. A fotodegradação do etilenoglicol formou ácidos carboxílicos de baixa massa molar, como por exemplo os ácidos glicólico, oxálico e fórmico.FAPESPCNP

Entrevista com Ottmar Ette

A entrevista com o Catedrático de Literatura Comparada e Línguas Românicas Ottmar Ette foi realizada na Universidade de Potsdam em 2018 e teve por objetivo expor as ideias do professor acerca de diferentes abordagens teóricas trazidas pelo estudioso em suas obras. Os questionamentos tratam do contexto contemporâneo, da mobilidade nos dias atuais, do conceito de Transárea, deslocamentos e influência na formação do “eu”, representados na literatura; abordam também a epistemologia das dimensões dos movimentos em seus níveis e o reconhecimento da literatura como importante provedora de conhecimento sobre e para a vida. Além disso, Ette versa sobre a literatura brasileira e sua relevância no cenário mundial e eleva o reaparecimento de figuras femininas e valorização da escrita feminina. Por último, pronuncia algumas palavras sobre o livro WeltFraktale: Wege durch die Literaturen der Welt e seu conceito de literatura de mundo. Assim sendo, a presente entrevista possibilitou uma melhor compreensão de alguns conceitos tratados pelo teórico, bem como trouxe contribuições teóricas e analíticas às diferentes linhas de estudos literários

Implementação do gerenciamento por categorias para medicamentos em uma rede farmacêutica

Devido ao crescimento do mercado de varejo farmacêutico, às mudanças recentes na forma de exposição dos produtos e à necessidade de entender os consumidores, realizou-se a implementação do gerenciamento por categorias para medicamentos em uma rede farmacêutica. O gerenciamento por categorias possibilita a análise dos produtos trabalhados em grupos de itens que possuam características semelhantes entre si, além de melhorar o atendimento às necessidades do consumidor. Por meio da análise de dados, conhecimento dos produtos e reuniões com os gestores da empresa foi possível entender as particularidades do mercado e definir estratégias, metas e ações para cada categoria. O diferencial desse trabalho é propor indicadores que comparam os diferentes medicamentos para compor um indicador global. Os resultados obtidos permitem classificar as diferentes categorias a partir de um indicador global, possibilitando a seleção de categorias e produtos para o desenvolvimento de ações diferenciadas

Distinct levels of quality of treated soybean seeds evaluated in alternative substrates to the germination test / Níveis distintos de qualidade de sementes de soja tratadas avaliadas em substratos alternativos ao teste de germinação

The aim was to investigate alternative substrates to the germination test with treated soybean seeds, considering distinct seed quality. Seeds with distinct levels of quality, the fungicide fludioxonil+metalaxyl-M+thiabendazole and the insecticides imidacloprid+thiodicarb, bifenthrin+imidacloprid and thiamethoxam, associated or not, were used to compose the treatments. The standard methods of the Rules for Seed Analysis, paper rolls and sand, and alternative methods, vermiculite between paper and sand between paper, were used as substrates. The variables evaluated were: first count, abnormal seedlings and germination. For the first count there were interactions among the chemical treatment and the substrate, the chemical treatment and the quality level, and among the substrate and the quality level. For the variables abnormal seedlings and germination, both with triple interactions, T1 and T3 stood out in the distinct substrates and levels of quality with the greater abnormalities, and sand with the best percentages of normal seedlings between different treatments and levels of quality. The sand substrate presented greater stability of the results, being the most suitable for treatments considered a problem for the standard paper roll test. The grater the seed quality, the lower the problems with the germination test with treated seeds. 

Diagenesis of Holocene Beachrock in Northeastern Brazil: Petrology, Isotopic Evidence and Age

This work aims to understand beachrock formation during Holocene through petrology, geochemistry and dating of a core located 5,43m deep in relation to present-day sea-level in the Piedade Beach in Jaboatao dos Guararapes- PE. The core is located 143 meters distant from the coast line towards mainland. Four lithofacies have been identified, taking into account differences in texture and sedimentary structures. The framework grain size ranges from medium to very coarse sand, indicating variations in depositional energy. Petrographic data indicate that the beachrocks have values of 64.23% to 70.69% of framework composed of quartz grains. Carbonate cement (represents 13.5%) consisting of high magnesium calcite surrounding grains as isopachous fringe (4.15% to 11.95%), micritic cement (0.60% to 6.42%) and equant cement (0.26% to 7.01%), indicates marine environment precipitation. The results of the isotopic composition of carbon and oxygen present valuesof 3.09‰ to 3.89‰, with an average of 3.63‰ to δ13CPDB and of -0.91‰ to 0.96‰, with an average of 0.54‰ to δ18OPDB, suggesting that the cement is formed in a shallow marine environment with freshwater influence. The values obtained in paleotemperature vary from 21ºC to 30ºC, with an average of 23ºC, with little variation indicating precipitation in a shallow water environment. In the study area, the beachrocks are indicators of sea level and the results suggest that between 7.509 years B.P. and 5982 years B.P. there was a marine transgression process, with sea level 9.18 m lower than the current sea level

Decreased expression of miR-146a and miR-155 contributes to an abnormal Treg phenotype in patients with rheumatoid arthritis

Objectives: MicroRNAs (miRNAs) have been implicated in the pathogenesis of autoimmune diseases, not least for their critical role in the regulation of regulatory T cell (Treg) function. Deregulated expression of miR-146a and miR-155 has been associated with rheumatoid arthritis (RA). We therefore investigated miR-146a and miR-155 expression in Tregs of patients with RA and their possible impact on Treg function and disease activity. Methods: Expression of miR-146a and miR-155 was assessed in RA patients and controls. MiRNA expression was correlated with disease activity and expression of target genes. Interference with biological activity of miRNAs was evaluated in functional Treg assays. Results: Diminished upregulation of miR-146a and miR-155 in response to T cell stimulation was found in Tregs of RA patients. Diminution of miR-146a expression was observed in particular in patients with active disease, and correlated with joint inflammation. In patients with active RA, Tregs demonstrated a pro-inflammatory phenotype characterised by inflammatory cytokine expression. This was due to an augmented expression and activation of signal transducer and activator transcription 1 (STAT1), a direct target of miR-146a. Conclusions: Our results suggest that in RA miR-146a facilitates a pro-inflammatory phenotype of Tregs via increased STAT1 activation, and contributes thereby to RA pathogenesis

Educadores e estudantes: um olhar para a afetividade nas Altas Habilidades/Superdotação

Generally cognitive development is the focus regarding high abilities/giftedness so affective development receives less attention from parents and educators. Based on this, the objective of this text is debating the importance of the gifted people’s affectivity. Methodology was a case study about a gifted student. Instruments were a questionnaire by Perez and Freitas (2012) to identify gifted adults’ indicators and a semi structured interview. Results point to the importance of paying attention on affective aspects of students’ development and the importance of educators’ formation to they teach gifted students in classroom. We consider neglecting affectivity is a possible source of negative consequences for gifted students in their adult life. Also the educator’s formation is not only the professional preparation but it includes personal preparation. Finally, the first thing educators need to do is identifying gifted students. It is necessary to know at least about high abilities to identify them.http://dx.doi.org/10.5902/1984686X14421As pessoas com altas habilidades/superdotação (AH/SD) geralmente recebem destaque em seu desenvolvimento cognitivo, o que resulta em menos atenção por parte de pais e educadores no desenvolvimento afetivo. Com base nisso, o objetivo deste texto é discutir a importância da afetividade em estudantes com AH/SD. A metodologia foi um estudo de caso com uma estudante com AH/SD. Os instrumentos utilizados foram o questionário para identificação de indicadores de AH/SD em adultos desenvolvido por Perez e Freitas (2012) e uma entrevista semiestruturada. Os resultados mostram que é necessário atentar para os aspectos afetivos destes estudantes em seu desenvolvimento e a importância da formação de educadores para trabalhar com AH/SD em sala de aula. Considera-se que a negligência da afetividade pode trazer consequências negativas para a vida adulta do estudante com AH/SD. Bem como que a formação do educador não se restringe ao seu preparo profissional, mas amplia-se ao nível pessoal. Por fim, o primeiro passo aos educadores é identificar estes estudantes. Para identifica-los é preciso pelo menos conhecer as AH/SD