FACILE HYDROTHERMAL SYNTHESIS OF NIOBIUM PENTOXIDE SEMICONDUCTOR AND THEIR APPLICATION IN THE PHOTODEGRADATION OF DYES AND REDUCTION OF FREE FAT ACIDS IN WASTE OIL.

We report a facile hydrothermal method for the synthesis of niobium pentoxide (Nb2O5) under two different temperatures, 120 °C (Nb2O5-120) and 150 °C (Nb2O5-150). The obtained materials were characterized by structural, optical and morphological techniques. Also, the photocatalytic properties of the Nb2O5 samples were evaluated in two reactions under ultraviolet (UVC) irradiation: degradation of methylene blue (MB) and indigo carmine (IC) dyes; and esterification of free fatty acids (FFA) present in waste cooking oil (WCO). The Nb2O5 was formed at different temperatures of synthesis, and the increase in temperature did not cause significant changes in the structural and optical characteristics, but resulted in an increased surface area of the synthesized materials. Both synthesized materials showed excellent efficiency for dye photodegradation. The sample Nb2O5-150 presented the best performance for the MB photodegradation, with almost 85% of the removal efficiency. In this case, the adsorption of MB molecules on the surface of the material was high due to the favorable electrostatic interaction and also because of its high surface area. For the IC photodegradation, the adsorption was insignificant, and both samples presented approximately 100% of the removal efficiency. These materials were also promising for the reduction of free fat acids in waste oil by photoesterification

Sirolimus-Eluting Versus Paclitaxel-Eluting Stent Implantation for the Percutaneous Treatment of Left Main Coronary Artery Disease A Combined RESEARCH and T-SEARCH Long-Term Analysis

ObjectivesThe purpose of this study was to investigate the long-term clinical and angiographic profile of sirolimus-eluting stent (SES) versus paclitaxel-eluting stent (PES) in patients undergoing percutaneous intervention for left main (LM) coronary disease.BackgroundThe long-term clinical and angiographic impact of SES as opposed to PES implantation in this subset of patients is unknown.MethodsFrom April 2002 to March 2004, 110 patients underwent percutaneous intervention for LM stenosis at our institution; 55 patients were treated with SES and 55 with PES. The two groups were well balanced for all baseline characteristics.ResultsAt a median follow-up of 660 days (range 428 to 885), the cumulative incidence of major adverse cardiovascular events was similar (25% in the SES group vs. 29%, in the PES group; hazard ratio 0.88 [95% confidence interval 0.43 to 1.82]; p = 0.74), reflecting similarities in both the composite death/myocardial infarction (16% in the SES group and 18% in the PES group) and target vessel revascularization (9% in the SES group and 11% in the PES group). Angiographic in-stent late loss (mm), evaluated in 73% of the SES group and in 77% of the PES group, was 0.32 ± 74 in the main and 0.36 ± 0.59 in the side branch in the SES group vs. 0.46 ± 0.57 (p = 0.36) and 0.52 ± 0.42 (p = 0.41) in the PES group, respectively.ConclusionsIn consecutive patients undergoing percutaneous LM intervention, PES may perform closely to SES both in terms of angiographic and long-term clinical outcome