Hydrothermal Crystallization of Bismuth Oxychlorides (BiOCl) Using Different Shape Control Reagents

Bismuth oxychloride photocatalysts were obtained using solvothermal synthesis and different additives (CTAB—cetyltrimethylammonium bromide, CTAC—cetyltrimethylammonium chloride, PVP–polyvinylpyrrolidone, SDS–sodium dodecylsulphate, U—urea and TU—thiourea). The effect of the previously mentioned compounds was analyzed applying structural (primary crystallite size, crystal phase composition, etc.), morphological (particle geometry), optical (band gap energy) parameters, surface related properties (surface atoms’ oxidation states), and the resulted photocatalytic activity. A strong dependency was found between the surface tension of the synthesis solutions and the overall morpho-structural parameters. The main finding was that the characteristics of the semiconductors can be tuned by modifying the surface tension of the synthesis mixture. It was observed after the photocatalytic degradation, that the white semiconductor turned to grey. Furthermore, we attempted to explain the gray color of BiOCl catalysts after the photocatalytic decompositions by Raman and XPS studies.

Temperature Dependence of Micellization Properties of Binary Mixtures of Sodium Decylsulphate with Sodium Dodecylsulphate in Water

Conductance measurement method has been used to determine the critical micelle concentration (CMC) and counterion binding constant values of binary mixtures of sodium decylsulphate (SDeS) with sodium dodecylsulphate (SDS) in water at four different temperatures ranging from 298 K to 313 K at 5 K intervals. Rubingh′s model has been used to calculate the mixed micellization properties viz. mixed micelle composition, activity coefficient of the components, and mutual interaction parameter between the components. Variation of these mixed micellization properties with temperature has been studied. The studied binary surfactant mixtures show attractive interaction between the components and it decreases with increase in temperature, which is an interesting trend. Thermodynamic parameters of mixed micellization have also been calculated. The enthalpy (ΔH°mic) and entropy (ΔS°mic) of micellization compensate each other.

The impact of a hygroscopic chitosan coating on the controlled release behaviour of zinc hydroxide nitrate–sodium dodecylsulphate–imidacloprid nanocomposites

The hydrophilic and hygroscopic nature of chitosan creates gel layer that slowed the ion exchange process between intercalated imidacloprid and incoming anion.

Análisis electroforético de proteínas del veneno de Bothrops atrox “jergón” (Ofidia: Viperidae) de distintas zonas geográficas de la Amazonia Peruana

Análisis electroforético de proteínas del veneno de Bothrops atrox “jergón” (Ofidia: Viperidae) de distintas zonas geográficas de la Amazonia Peruana Electrophoretic analysis of proteins in the venom of Bothrops atrox “lancehead” (Ofidia: Viperidae) from different geographical zones to the Peruvian Amazon Rommel Rojas, Roberson Ramírez, Marianela Cobos y Juan Castro Centro de Investigaciones de Recursos Naturales-CIRNA Universidad Nacional de la Amazonia Peruana-UNAP. Apartado postal 496S Facultad de Ciencias Biológicas. DOI: https://doi.org/10.33017/RevECIPeru2011.0050/ RESUMEN Los venenos de serpientes son secreciones endógenas constituidas en su mayor parte por proteínas, que pueden causar diversos cuadros sintomatológicos, y en algunos casos la muerte. Las serpientes fueron recolectadas en el campo por muestreos herpetológicos utilizando la técnica del revelamiento por encuentros casuales [1] y el veneno recolectado por ordenamiento manual. Usando la técnica de electroforesis discontinua en gel de poliacrilamida [2] al 7.5% y 12% con dodecilsulfato de sodio (PAGE-SDS) se analizaron los perfiles electroforéticos de 5 especímenes de Bothrops atrox “jergón” provenientes de 5 zonas geográficas de la Amazonia Peruana, siendo evaluadas en condiciones reductoras utilizando veneno centrifugado, asimismo se realizó la cuantificación de las proteínas por el método espectrofotométrico utilizando el método de Biuret [3]. Los resultados muestran la presencia de proteínas en los rangos de 14 kD a 116 kD, obteniéndose variaciones en la cantidad de bandas proteínas, 9,11,8,7,8 para las poblaciones de Moena Caño, Isla Iquitos, Panguana, Genaro Herrera y Nina Rumi, mientras que la cuantificación muestra la existencia de una mayor cantidad de proteínas en el veneno de la serpiente proveniente de Isla Iquitos (67.41 mg/ml) y una menor cantidad en el espécimen de Genaro Herrera (32.13 mg/ml). Se concluye mencionando la existencia de variaciones en los perfiles electroforéticos y cantidades de las proteínas presentes en el veneno de Bothrops atrox de la Amazonia Peruana. Descriptores: venenos, proteínas, electroforesis, poliacrilamida, cuantificación. ABSTRACT The snake´s venoms are endogenous secretions constituted for proteins and can produce different symptomatology and in some cases the dead. Using the electrophoretic technique in polyacrylamide discontinuous gel of 7.5% and 12% whit sodium dodecylsulphate (PAGE-SDS) in reductions conditions were carried on a protein analysis of the venom in 5 Bothrops atrox snake´s from 5 different geographical zones to the Peruvian Amazon using centrifuge crude venom, additionally the proteins were quantification for using an spectrophotometer following the Biuret method. The results evidence the presents of different bands in the proteins, in ranges of 14 kD to 116 kD, finding 9, 11,8,7,8 bands of proteins for the populations of Moena Caño, Isla Iquitos, Panguana, Genaro Herrera and Nina Rumi, while the quantification show the presents to major quantity of protein in the snake from Isla Iquitos (67.41 mg/ml) and a less quantity in the specie from Genaro Herrera (32.13 mg/ml). We conclude mentioning the existence of variations in the electrophoretic profile and quantification to proteins from the venom of Bothrops atrox to the Peruvian Amazon. Keywords: venoms, proteins, electrophoretic, polyacrylamide, quantification.