Surface treatment of dental porcelain with CO2 laser: porosity analysis and AFM.

The effect of CO2 continuous laser irradiation on the surface properties of veneering porcelains has already been tested. The surface observed after laser irradiation is similar to that achieved by auto-glaze in terms of roughness and color parameters (Sgura R, et al. Dental Materials 2011;27(Suppl. 1):e72–73). The purpose of this study was to analyze the surface porosity of porcelain discs after CO2 laser treatment and compare it to auto-glaze treatment, in furnace. A morphological analysis of the porcelain surface was conducted using atomic force microscopy (AFM) and conventional optical microscopy (OM).

Pela construção de um estado de crítica: a reflexão crítica como campo dialógico

O texto aqui apresentado foi originalmente elaborado para o debate sobre a crítica de arte no I Congresso de Jornalismo realizado em São Paulo, pela Revista Cult, em Maio de 2009. Tendo como campo de trabalho a prática artística e a docência e envolvida no processo de formação de artistas desde 1982, meu objetivo foi argumentar a favor de um entendimento da crítica como dispositivo da arte e, portanto, atributo não só de críticos, mas também de artistas. Defendo a idéia da manutenção de um ‘estado de crítica' para o contexto brasileiro a partir de uma relação dialógica e internacionalizada, envolvendo também a fala crítica de artistas. Para isso reporto às práticas adotadas no século XX pelos artistas que colaboraram para inserir a obra de arte no campo programático da auto-crítica e da crítica ao sistema, evidenciando assim a posição destes como agente ativos no sistema

Increased Metallothionein I/II Expression in Patients with Temporal Lobe Epilepsy

In the central nervous system, zinc is released along with glutamate during neurotransmission and, in excess, can promote neuronal death. Experimental studies have shown that metallothioneins I/II (MT-I/II), which chelate free zinc, can affect seizures and reduce neuronal death after status epilepticus. Our aim was to evaluate the expression of MT-I/II in the hippocampus of patients with temporal lobe epilepsy (TLE). Hippocampi from patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) and patients with TLE associated with tumor or dysplasia (TLE-TD) were evaluated for expression of MT-I/II, for the vesicular zinc levels, and for neuronal, astroglial, and microglial populations. Compared to control cases, MTLE group displayed widespread increase in MT-I/II expression, astrogliosis, microgliosis and reduced neuronal population. In TLE-TD, the same changes were observed, except that were mainly confined to fascia dentata. Increased vesicular zinc was observed only in the inner molecular layer of MTLE patients, when compared to control cases. Correlation and linear regression analyses indicated an association between increased MT-I/II and increased astrogliosis in TLE. MT-I/II levels did not correlate with any clinical variables, but MTLE patients with secondary generalized seizures (SGS) had less MT-I/II than MTLE patients without SGS. In conclusion, MT-I/II expression was increased in hippocampi from TLE patients and our data suggest that it is associated with astrogliosis and may be associated with different seizure spread patterns.

56-month clinical performance of Class I and II resin composite restorations

Objective: This study evaluated the 56-month clinical performance of Class I and II resin composite restorations. Filtek P60 was compared with Filtek Z250, which are both indicated for posterior restorations but differ in terms of handling characteristics. The null hypothesis tested was that there is no difference in the clinical performance of the two resin composites in posterior teeth. Material and Methods: Thirty-three patients were treated by the same operator, who prepared 48 Class I and 42 Class II cavities, which were restored with Single Bond/Filtek Z250 or Single Bond/Filtek P60 restorative systems. Restorations were evaluated by two independent examiners at baseline and after 56 months, using the modified USPHS criteria. Data were analyzed statistically using Chi-square and Fisher's Exact tests (alpha=0.05). Results: After 56 months, 25 patients (31 Class I and 36 Class II) were analyzed. A 3% failure rate occurred due to secondary caries and excessive loss of anatomic form for P60. For both restorative systems, there were no significant differences in secondary caries and postoperative sensitivity. However, significant changes were observed with respect to anatomic form, marginal discoloration, and marginal adaptation. Significant decreases in surface texture were observed exclusively for the Z250 restorations. Conclusions: Both restorative systems can be used for posterior restorations and can be expected to perform well in the oral environment.

Essays on the history of Brazilian dipterology. I. The first notices about Brazilian Diptera (16th century)

Essays on the history of Brazilian dipterology. I. The first notices about Brazilian Diptera (16th century). This paper presents a historical resume of the first notices about Brazilian Diluent during the 16th century, given by Francisco Pires in 1552 (the oldest mention known), Jose de Anchieta, Leonardo do Valle, Pero de Magalhaes de Gandavo, Jean de Lery and Gabriel Soares de Souza, ending with Fernao Cardim, who made the last mentions of Brazilian Diptera in that century.

Crisis y superación en el ámbito de la Geografía crítica: construyendo la metageografía.

El punto de inicio del razonamiento desarrollado para la construcción de lo que se denomina metageografía, parte con el reconocimiento de un estado de crisis en la Geografía, y en segundo lugar, de su rol como posibilidad, a pesar de ser una ciencia fragmentada, de comprender el mundo moderno, pues su conocimiento puede constituirse en un movimiento hacia la totalidad. En un sentido más amplio, se reflexiona sobre el lugar de la Geografía en la explicación de la realidad en constante cambio. ¿Es posible pensar que, a pesar de sus avances, la Geografía se encuentra en un estado de crisis? Nos enfrentamos con la obligación de revelar sus indicios y, por consiguiente, la necesidad de construir un camino hacia adelante en la necesidad de comprender la realidad desde o por la Geografía. La metageografía es una propuesta teórico-metodológica para la superación de la situación de crisis en que la disciplina se encuentra, a partir de la práctica socioespacial como modo explicativo.

Neoproterozoic glacial deposits from the Aracuai orogen, Brazil: Age, provenance and correlations with the Sao Francisco craton and West Congo belt

Glacigenic diamictite successions of the Macaubas Group are widespread in the western domain of the Aracuai orogen, east of the Sao Francisco craton (Brazil). Diamictites also occur on this craton and in the African counterpart of the Aracuai orogen, the West Congo belt. Detrital zircon grains from the matrix of diamictites and sandstones from the Macaubas Group were dated by the U-Pb SHRIMP technique. The geochronological study sets the maximum depositional age of the glacial diamictites at 900 Ma, and indicates multiple sources for the Macaubas basin with ages ranging from 900 to 2800 Ma. Sm-Nd T-DM model ages, determined on whole rock samples, range from 1.8 Ga to 2.5 Ga and get older up-section. Comparison of our data with those from the cratonic area suggest that these glacial deposits can be correlated to the Jequitai and Carrancas diamictites in the Sao Francisco craton, and to the Lower Mixtite Formation of the West Congolian Group, exposed in Africa. The 900-1000 Ma source is most probably represented by the Zadinian-Mayumbian volcanic rocks and related granites from the West Congo belt. However, one of the most voluminous sources, with ages in the 1.1-1.3 Ga interval, has not been detected in the Sao Francisco-Congo craton. Possible sources for these grains could occur elsewhere in Africa, or possibly from within the Brasilia Belt in western central Brazil. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.