Comparação entre os efeitos de soluções salinas hiper e isotônicas no pincamento e liberação da aorta abdominal infra-renal em cães

A mortalidade e morbidez na cirurgia para o tratamento das doenças da aorta dependem de uma série de fatores, entre eles, medidas terapêuticas trans-operatórias. De capital importância são os critérios adotados para a infusão de soluções, tanto no que diz respeito ao volume quanto à qualidade. o objetivo deste trabalho foi avaliar o efeito de soluções salinas hiper e isotônicas durante o pinçamento e após a liberação da aorta abdominal infra-renal. Foram avaliados parâmetros hematológico-bioquímicos, hemodinâmicos e fluxo sangüíneo regional utilizando a técnica de distribuição de partículas radioativas com referencial arterial. Foram estudados 23 cães distribuídos aleatoriamente em três grupos experimentais. O grupo solução hipertônica se constituiu de 9 animais nos quais foi infundida solução de NaCI a 7,5% durante o período de pinçamento da aorta abdominal infra-renal. O grupo solução isotônica se constituiu de 8 animais nos quais foi infundida solução de NaCI a 0,9% durante o período de pinçamento da aorta. Um terceiro grupo controle, constituído de 6 animais, não era submetido ao pinçamento da aorta, e nele se determinava o fluxo regional basal e a interferência do próprio modelo experimental no comportamento dos parâmetros estudados. Conclui-se que a infusão de solução hipertônica provocou aumento significante da osmolalidade e da concentração de sódio séricos. Não foram observadas diferenças significantes entre os grupos experimentais quanto aos parâmetros hemodinâmicos estudados. Constatou-se fluxo pulmonar significantemente maior no grupo tratado com solução hipertônica.Aortic surgery morbidity and mortality depends on multiple factors and some of them are related to intra-operative fluid management. The management of solution's infusion is of paramount importance regarding composition and volume. The objective of this experiment was to evaluate the effect of hyper and isotoníc saline solutions in dogs submited to clamping and unclamping of the infra-renal abdominal aorta. Haematological and biochemical parameters, haemodynamics and regional blood flow were evaluated. Twenty three dogs were studied, randomly distributed in three experimental groups.The hypertoníc solution group had 9 dogs in whom a 7.5% NaCI solution was infused during the clamping period. The isotoníc solution group had 8 dogs in whom a 0.9% NaCI solution was infused during the same period. These two groups were matched against a control group of 6 dogs in whom there was no aortic clamping. In this last group the basic regional blood flow and the possible interferences of the experimental model upon the studied parameters were determined. In conclusion, the infusion of hypertoníc solution was followed by a significant osmolality an sodium concentration increase. Significant differences were not observed in haemodynamic parameters. The pulmonary blood flow was significantly higher in the hypertoníc group

Improving adhesion between luting cement and zirconia-based ceramic with an alternative surface treatment

This study evaluated the influence of an alternative surface treatment on the microshear bond strength (mu sbs) of zirconia-based ceramic. Thirty-five zirconia disks were assigned to five groups according to the following treatments: Control (CO), glass and silane were not applied to the zirconia surface; G1, air blasted with 100 mu m glass beads + glaze + silane; G2, a gel containing 15% (by weight) glass beads applied to the ceramic surface + glaze + silane; G3, a gel containing 25% (by weight) glass beads applied to the ceramic surface + glaze + silane; and G4, a gel containing 50% (by weight) glass beads applied to the ceramic surface + glaze + silane. The specimens were built up using RelyX ARC (R), according to the manufacturer's recommendations, and inserted in an elastomeric mold with an inner diameter of 0.8 mm. The mu sbs test was performed using a testing machine at a crosshead speed of 0.5 mm/min. ANOVA and Tukey's test (p < 0.05) were applied to the bond strength values (in MPa). CO (15.6 +/- 4.1) showed the lowest mu sbs value. There were no statistical differences between the G1 (24.9 +/- 7.4), G2 (24.9 +/- 2.3), G3 (35.0 +/- 10.3) and G4 (35.3 +/- 6.0) experimental groups. Those groups submitted to surface treatments with higher concentrations of glass showed a lower frequency of adhesive failures. In conclusion, the glass application improved the interaction between the ceramic and the luting cement29

Yield and chemical properties of rubber of Hevea clones according to phenological stages

The objective of this work was to evaluate the yield performance and macronutrient content of rubber extracted from four Hevea brasiliensis clones, under different tapping systems and plant phenological stages. The experiment was carried out in the 2010 and 2011 crop seasons, in a split-plot randomized complete block design, with four replicates. The main treatments - GT 1, PB 235, IAN 873, and RRIM 600 clones - were allocated in the plots, and the secondary treatments, which were the tapping systems 1/2S d/2, 1/2S d/4 ET 2.5%, and 1/2S d/7 ET 2.5%, were allocated in the subplots. The analyzed variables were natural rubber yield and macronutrient contents. Samples of natural rubber were obtained in the leaf development, mature leaf, and leaf senescence phenological stages. Rubber yield and its macronutrient contents are more influenced by tapping practice than by genetic material in the restrictive phenological stages of foliage.El objetivo de este trabajo fue evaluar el desempeño productivo y el contenido de macronutrientes del \ud caucho extraído de cuatro clones de Hevea brasiliensis, en diferentes sistemas de sangría y estados fenológicos \ud de las plantas. El experimento fue realizado en los años agrícolas de 2010 y 2011, en diseño experimental de \ud bloques completos al azar, en parcelas subdivididas, con cuatro repeticiones. Los tratamientos principales \ud – clones GT 1, PB 235, IAN 873 e RRIM 600 – fueron ubicados en las parcelas, y los subtratamientos, que \ud fueron los sistemas de sangría ½S d/2, ½S d/4 ET 2,5% y ½S d/7 ET 2,5%, se ubicaron en las subparcelas. Las \ud variables analizadas fueron producción y contenido de macronutrientes. Las muestras fueron obtenidas en los \ud estados fenológicos de brotación foliar, hojas maduras y senescencia foliar. La producción y los contenidos de \ud macronutrientes del caucho son más influenciados por la práctica de sangría que por el material genético en los \ud estados fenológicos más restrictivos para el follaje de caucho