SGTPy: A Python Code for Calculating the Interfacial Properties of Fluids Based on the Square Gradient Theory Using the SAFT-VR Mie Equation of State.

In this work, we showcase SGTPy, a Python open-source code developed to calculate interfacial properties (interfacial concentration profiles and interfacial or surface tension) for pure fluids and fluid mixtures. SGTPy employs the Square Gradient Theory (SGT) coupled to the Statistical Associating Fluid Theory of Variable Range employing a Mie potential (SAFT-VR-Mie). SGTPy uses standard Python numerical packages (i.e., NumPy, SciPy) and can be used under Jupyter notebooks. Its features are the calculation of phase stability, phase equilibria, interfacial properties, and the optimization of the SGT and SAFT parameters for vapor-liquid, liquid-liquid and vapor-liquid-liquid equilibria for pure fluids and multicomponent mixtures. Phase equilibrium calculations include two-phase and multiphase flash, bubble and dew points, and the tangent plane distance. For the computation of interfacial properties, SGTPy incorporates several options to solve the interfacial concentration, such as the path technique, an auxiliary time function, and orthogonal collocation. Additionally, the SGTPy code allows the inclusion of subroutines from other languages (e.g., Fortran, and C++) through Cython and f2py Python tools, which opens the possibility for future extensions or recycling tested and optimized subroutines from other codes. Supporting Information includes a review of the theoretical expressions required to couple SAFT-VR-Mie equation of state with the SGT. The use and capabilities of SGTPy are illustrated through step by step examples written on Jupyter notebooks for the cases of pure fluids and binary and ternary mixtures in bi- and three- phasic equilibria. The SGTPy code can be downloaded from https://github.com/gustavochm/SGTPy.

Evaluation of wood degradation rates by Teredinidae (Mollusca: Bivalvia) in two ecologically distinct areas, and temperature and salinity influences on the cellulolytic activity of associated bacteria.

Teredinidae (shipworms) is a family of marine wood-boring bivalves that has an important role in the degradation of wood through its symbiotic relationship with cellulolytic bacteria. To evaluate the rate of degradation of wood by teredinids in two sites with different oceanographic conditions in Rio de Janeiro State, Brazil, artificial structures composed of pine wood sheets were immersed in the ocean for three months at Arraial do Cabo in an area under the influence of upwelling, and at Ilha Grande Bay under tropical and oligotrophic influences. After the immersion period, teredinids were removed from the collectors, identified, and counted. Wood consumption by the teredinids was quantified by comparing the dry weights of the collectors before and after immersion. Associated bacteria were isolated and their cellulolytic activities evaluated at different temperatures and salinities. Two Teredinidae species were recorded: Bankia gouldi and Lyrodus floridanus. The highest wood degradation rate and enzymatic activities of the isolated bacterial strains were recorded at Arraial do Cabo, suggesting that upwelling influenced the activities of those species.

Dispersal of potentially pathogenic bacteria by plastic debris in Guanabara Bay, RJ, Brazil.

Analyses of thermotolerant coliform and heterotrophic bacteria as well as Escherichia coli and Vibrio species were carried out on plastic samples and in the surrounding waters of Guanabara Bay to evaluate plastic debris as vehicles of bacterial dispersal. Chemical characterizations of plastics were performed using Fourier transform infrared spectroscopy (FTIR). Plastic debris with high coliform contents were found, while their respective water samples had only low titers. No correlations were observed, however, between the amounts of bacteria and the chemical compositions of the plastic debris. Forty-four bacterial strains were PCR-confirmed as E. coli pathotypes, and 59 strains of Vibrio spp. (with 12 being identified as Vibrio cholerae [6], Vibrio vulnificus [5], and Vibrio mimicus [1]). These findings suggest these plastics can function as a substrate for bacterial biofilms (including pathogens). These debris, in turn, can be dispersed in aquatic environments not otherwise showing recent fecal bacterial contamination.

Impacto del programa de coordinadores hospitalarios en la obtención de riñones para trasplante renal / Role of the transplant coordinator program in organ procurement for transplant

La dificultad para la obtención de órganos para trasplante es uno de los principales factores que limitan el desarrollo de los programas de reemplazo de órganos. En la búsqueda de altervativas para incrementar la donación de órganos, se llevó a cabo un estudio piloto del Centro Nacional de Diálisis y Trasplante con el Programa de Coordinadores Hospitalarios (PCH), durante 6 meses, para cumplir las siguientes funciones: difundir programas de educación contínua, detección y vigilancia de donantes potenciales, solicitud de autorización familiar e interconexión informativa. Se detectaron 45 predonantes con una edad promedio de 25.8 ñ 1.6 años, 36 del sexo masculino (80 por ciento). Ninguno estaba registrado como donante voluntario. Las principales causas de muerte fueron: los traumatismos cráneo-encefálicos en un 57.8 por ciento y los accidentes cerebrovasculares en 22.2 por ciento. El 42.3 por ciento de los predonantes fue detectado en los servicios de emergencia, 33.3 por ciento en las unidades de cuidado intensivo y el 24 por ciento en recuperación de cirugía. La efectividad de conversión de predonantes a donantes fue de 19 por ciento. El 71 por ciento no pudo ser convertido a donante efectivo por las siguientes causas: negativa de autorización familiar 44 por ciento, paro cardio-respiratorio precoz 13 por ciento, función renal alterada 6 por ciento, falta de apoyo ventilatorio 6 por ciento, antígeno de superficie para hepatitis B (+) 6 por ciento, no disponibilidad del equipo quirúrgico 3 por ciento. En el 9 por ciento restante no se reportó la causa. Se cpncluye que el Programa de Coordinación Hospitalaria es efectivo para la detección de pre-donantes, suministrando además una información útil tanto para determinar posibles fallas en el manejo de donantes potenciales como para evaluar y orientar las campañas de captación de donantes voluntarios