Search results for "CBS"
showing 4 items of 24 documents
Polychlorinated Biphenyls in Sediments from Sicilian Coastal Area (Scoglitti) using Automated Soxhlet, GC-MS, and Principal Component Analysis
2014
A methodology for the PAHs and PCBs congener determination in sediment samples has been revised. We determined the distributions of PAHs and PCBs in the superficial sediments of the Scoglitti (Italy) coastal area to provide data for comparison with other marine systems and to hypothesize the sources. Extraction yield, for PCB, was never less than 60% in most cases, while for PAHs, utilizing perdeuterated surrogate standard (benz[a]anthracene-d12 and anthracene-d10) was never less than 72%. The total concentration of the 16 PAHs investigated, expressed as the sum of concentrations, PAHs, varied from 1–5087 μg/kg of dry matrix, while the PCBs ranged from detection limit to 36 μg/kg of dry mat…
Estimation of isotropic nuclear magnetic shieldings in the CCSD(T) and MP2 complete basis set limit using affordable correlation calculations
2013
A linear correlation between isotropic nuclear magnetic shielding constants for seven model molecules (CH2O, H2O, HF, F2, HCN, SiH4 and H2S) calculated with 37 methods (34 density functionals, RHF, MP2 and CCSD(T)), with affordable pcS-2 basis set and corresponding complete basis set results, estimated from calculations with the family of polarization-consistent pcS-n basis sets is reported. This dependence was also supported by inspection of profiles of deviation between CBS estimated nuclear shieldings and shieldings obtained with the significantly smaller basis sets pcS-2 and aug-cc-pVTZ-J for the selected set of 37 calculation methods. It was possible to formulate a practical approach o…
Análisis del la relación del genotipado y marcadores de estrés oxidativo con la presencia y grado de vasculopatía periférica en pacientes con diabete…
2014
RESUMEN: Padecer diabetes tipo 2 (DM2) ejerce un efecto independiente y multiplicador en la incidencia de complicaciones vasculares, añadido a la presencia de factores de riesgo clásicos. No todos los diabéticos desarrollan con la misma gravedad la vasculopatía periférica (VP). Este riesgo está presente en la fase de prediabetes, donde las complicaciones vasculares pueden preceder a la aparición de la propia diabetes. La biología vascular ha puesto de manifiesto la participación de otros factores como el estrés oxidativo (EO) y el estado crónico inflamatorio en el incremento de este riesgo. Los principales sistemas conocidos de EO a nivel endotelial generan especies reactivas de oxígeno. Pa…
Photochemical sample treatment: A greener approach for PCBs analysis in sediments
2012
Electrical installations and industrial outlets are the major source in environment of chlorinated organic compounds. These are distributed in several geographical areas through long-range atmospheric transport and deposition. Additionally, chlorinated organic compounds can be introduced in the food chain and reach the consumers in very high levels. Besides toxicological studies on PCBs, recent research is focusing on more sophisticated analytical methods for PCBs detection. Distribution and dispersion of PCBs mostly occur through air, water, soils, and sediments. The latter are complex matrices whose analysis often involves costly extraction and purification procedures. In particular, PCBs…