Influence of pH, bleaching agents, and acid etching on surface wear of bovine enamel

ABSTRACT Development of new materials for tooth bleaching justifies the need for studies to evaluate the changes in the enamel surface caused by different bleaching protocols. Objective The aim of this study was to evaluate the bovine dental enamel wear in function of different bleaching gel protocols, acid etching and pH variation. Material and Methods Sixty fragments of bovine teeth were cut, obtaining a control and test areas. In the test area, one half received etching followed by a bleaching gel application, and the other half, only the bleaching gel. The fragments were randomly divided into six groups (n=10), each one received one bleaching session with five hydrogen peroxide gel applications of 8 min, activated with hybrid light, diode laser/blue LED (HL) or diode laser/violet LED (VHL) (experimental): Control (C); 35% Total Blanc Office (TBO35HL); 35% Lase Peroxide Sensy (LPS35HL); 25% Lase Peroxide Sensy II (LPS25HL); 15% Lase Peroxide Lite (LPL15HL); and 10% hydrogen peroxide (experimental) (EXP10VHL). pH values were determined by a pHmeter at the initial and final time periods. Specimens were stored, subjected to simulated brushing cycles, and the superficial wear was determined (μm). ANOVA and Tukey´s tests were applied (α=0.05). Results The pH showed a slight decrease, except for Group LPL15HL. Group LPS25HL showed the highest degree of wear, with and without etching. Conclusion There was a decrease from the initial to the final pH. Different bleaching gels were able to increase the surface wear values after simulated brushing. Acid etching before bleaching increased surface wear values in all groups

Repensar els estudis catalans des de la teoria queer

Catalan Studies are basically focused on national/linguistic identity, but recent debate on Catalan identity triggered by the current pro-independent process in Catalonia, may help reshape this academic field. A more diverse approach to Catalan culture should consider sexuality, which has traditionally been banished from literary analysis as a ‘private’ matter. Here, we discussed how queer theory can reframe Catalan Studies mainly by building a specific LGBT literary tradition, identifying queer episodes and characters in the canon, questioning received meanings, promoting interdisciplinary analysis of Catalan culture and exploring the role of queer subjectivity in history

Apuntes sobre el metabolismo socio-natural y los conflictos ambientales

Literature on environmental conflicts is marked by broad theoretical and methodological dispersion, which results from the very complexity and diversity of its object. The notion of social-natural metabolism may serve as the basis for an integrated perspective in which different environmental conflicts are explained with reference to common categories and in relation to other forms of social conflict. Social-natural metabolism refers to the link between nature and human societies which results from the human occupation of space, economic activities and the resulting generation of waste.”La literatura sobre conflictos ambientales presenta una gran dispersión teóricometodológica, producto de la complejidad y variedad de formas de su objeto. La noción de metabolismo socio-natural puede proporcionar la base para un enfoque integrador donde los distintos conflictos ambientales puedan comprenderse desde las mismas categorías básicas y en relación con otras formas de conflicto social. El concepto de metabolismo socio-natural refiere al vínculo entre sociedades humanas y naturaleza que resulta de la ocupación humana del espacio, su actividad económica y la consecuente generación de desechos

EL AMBIENTALISMO Y LA LUCHA CONTRA EL COMBO DEL SECTOR ELÉCTRICO (1998-2001)

En el año 2000, una parte del ambientalismo se sumó al movimiento de rechazo a la ley de privatización del Instituto Costarricense de Electricidad (ICE) llamada popular-mente el Combo sobre el sector eléctrico costarricense. Su aporte no se puede medir en la cantidad de afiliados o activistas que movilizó, si no por haber formulado una crítica ecológica  y una  crítica distributiva de los cambios en el sector eléctrico. El caso también ilustra los alcances y límites de las coincidencias entre el ambientalis-mo y demás movimientos sociales en Costa Rica

EL AMBIENTALISMO Y LA LUCHA CONTRA EL COMBO DEL SECTOR ELÉCTRICO (1998-2001)

En el año 2000, una parte del ambientalismo se sumó al movimiento de rechazo a la ley de privatización del Instituto Costarricense de Electricidad (ICE) llamada popularmente el Combo sobre el sector eléctrico costarricense. Su aporte no se puede medir en la cantidad de afiliados o activistas que movilizó, si no por haber formulado una crítica ecológica y una crítica distributiva de los cambios en el sector eléctrico. El caso también ilustra los alcances y límites de las coincidencias entre el ambientalismo y demás movimientos sociales en Costa Rica

La agricultura familiar campesina en Centroamérica: una apuesta estratégica frente a los desafíos de los territorios rurales

No hay resúmenes disponiblesRealidad: Revista de Ciencias Sociales y Humanidades No.137, 2013: 511-52

Proteção e Defesa Civil: introdução à Política Nacional - Curso 1

O Curso 1 - Proteção e Defesa Civil: introdução à Política Nacional foi desenvolvido pelo Ceped em parceria com a Sedec, em 2021, e faz parte da Capacitação em Proteção e Defesa Civil. O curso foi desenvolvido com o intuito de apresentar a temática Proteção e Defesa Civil, com ênfase na Política Nacional, nos seus principais conceitos e no contexto que a envolve.Módulo 1: Proteção e Defesa Civil no Brasil, p 10-42Módulo 2: Conceitos Preliminares, p 43-79Módulo 3: Contexto dos Desastres, p 80-96Políticas Sociai

Protein Interactions of the Mechanosensory Proteins Wsc2 and Wsc3 for Stress Resistance in Saccharomyces cerevisiae

Antifungal drug discovery and design is very challenging because of the considerable similarities in genetic features and metabolic pathways between fungi and humans. However, cell wall composition represents a notable point of divergence. Therefore, a research strategy was designed to improve our understanding of the mechanisms for maintaining fungal cell wall integrity, and to identify potential targets for new drugs that modulate the underlying protein-protein interactions in Saccharomyces cerevisiae. This study defines roles for Wsc2p and Wsc3p and their interacting protein partners in the cell wall integrity signaling and cell survival mechanisms that respond to treatments with fluconazole and hydrogen peroxide. By combined genetic and biochemical approaches, we report the discovery of 12 novel protein interactors of Wsc2p and Wsc3p. Of these, Wsc2p interacting partners Gtt1p and Yck2p, have opposing roles in the resistance and sensitivity to fluconazole treatments respectively. The interaction of Wsc2p with Ras2p was confirmed by iMYTH and IP-MS approaches and is shown to play a dominant role in response to oxidative stress induced by hydrogen peroxide. Consistent with an earlier study, Ras2p was also identified as an interacting partner of Wsc1p and Mid2p cell wall integrity signaling proteins. Collectively, this study expands the interaction networks of the mechanosensory proteins of the Cell Wall Integrity pathway