Characterization of aqueous silver nitrate solutions for leakage tests

OBJECTIVE: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. MATERIAL AND METHODS: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50%) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO3 solution and the primary teeth in 5% or 50% AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5%). RESULTS: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000). CONCLUSIONS: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth.

Modernizando o emprego p??blico

Os pa??ses da Organiza????o para Coopera????o e Desenvolvimento Econ??mico (OCDE) t??m algo em comum quando se fala das particularidades de governo: um consistente n??cleo de servi??o p??blico, ou seja, uma burocracia controlada centralmente, formada por pessoas que trabalham para os neg??cios de governo em minist??rios, ??rg??os e ag??ncias com estruturas e sistemas pr??prios. Estabilidade ??? ou o chamado emprego para toda a vida ??? e um regime especial s??o as caracter??sticas tradicionais do servi??o p??blico. Nas ??ltimas d??cadas, entretanto, diversas ??reas do servi??o p??blico perderam essa distin????o, porque, com os processos de reforma, um n??mero significativo de fun????es p??blicas passaram para o setor privado. Assim, muitas das suposi????es sobre como o servi??o p??blico funciona n??o s??o mais verdadeiras.

Den Moderna Synthen : Hur påverkar dess valmöjligheter det musikaliska skapandet?

En fallstudie i huruvida mångfalden av valmöjligheter och funktioner i en modern synth påverkar musikskapandeprocessen. Undersökningen fokuseras på att undersöka hur dagens kompositörer använder sig av ljudskapande i moderna synthar. Syftet med denna undersökning är att se om mångfald av funktioner i en modern synth påverkar musikskapandet, för att ge läsaren en tankeställare angående arbetsflödet i sitt musikskapande, så att en effektivisering av processen kan tillämpas och att om möjligt, ge rum för mera musikskapande och mindre teknikförståelse. Denna undersökning gjordes genom att genomföra ett antal intervjuer samt en kompletterande enkätundersökning. Slutstsen jag kommit fram till är att en mångfald av funktioner påverkar musikskapandet, antingen negativt eller positivt beroende på genre och kompositörens erfarenhet av synthar.

Exploração inicial da interface do software Acid Xpress

O professor, sentado diante de um computador, demonstra as diferentes partes que compõem a interface gráfica do software Acid Xpress, como “Track list (lista de faixas)”, “Timeline (linha do tempo)”, “Barra de transporte”, “Painel de exploração”, “Track properties (propriedades da faixa)”, “Janela de mixagem”, “Video preview (visualização de vídeo)” e “Soft synth properties (propriedades de sintetizador)”.

'Ti''O IND.2'/'Sn''O IND. 2 modificado com 'Ag IND. 2''O', para obtenção de fotocatalisadores

Pós-graduação em Química - IQ

Incorporação da apatita na superfície da liga Ti30ta empregando tratamento alcalino associado à eletrofiação de fibras de PCL

Pós-graduação em Engenharia Mecânica - FEG

Pour une nouvelle poétique de l'extase : Abdelwahab Meddeb et l'héritage des poètes arabes et persans de l'Antiquité et du Moyen Ãge. Comparaisons et pistes de lecture intertextuelles.

Ce travail a pour objectif d’analyser la production narrative et poétique de l’écrivain tunisien Abdelwahab Meddeb, en comparaison avec les ouvrages du Moyen Age arabe et persan. L’auteur reprend en effet, par le biais de pratiques intertextuelles, les ouvrages des philosophes et des écrivains orientaux qui plus ont marqué le monde musulman, en arrivant à en faire une synthèse originale. Cette perspective multiculturelle ouvre la voie à une instance narrative polyphonique, où les textes se confondent et se mélangent. En un premier moment, l’étude porte sur les théories intertextuelles et leur application chez Meddeb ; dans la deuxième partie, l’analyse se concentre sur les correspondances internes à l’œuvre meddebienne, pour laisser la place, dans la dernière partie, aux aspects intertextuels que le texte francophone entretient avec les autres auteurs.