RESUMEN
This paper reports on the synthesis and characterization of La2O3:Eu3+ luminescent aerogels fabricated by the sol-gel method and the supercritical drying technique. The % mol concentration of the Eu3+ ion was varied to study the effects on the luminescent properties of the aerogels. XRD and TEM analysis showed that the La2O3:Eu3+ aerogels exhibited a semi-crystalline behavior regardless of whether the concentration of europium was increased. SEM micrographs revealed a porous structure in the aerogels, which were composed of quasi-spherical nanoparticles that were interconnected and formed coral-shaped agglomerates. Photoluminescence spectroscopy characterization showed that the aerogels had an infrared emission located at λ = 793 nm, and the maximum photoluminescence emission intensity was observed for the aerogel with 50% Eu3+. The results demonstrate that, without heat treatment, it is possible to manufacture luminescent aerogels of rare-earth oxides that can be used in opto-electronic devices.
RESUMEN
In recent years, the consumption of vegetal-source proteins has been studied to determine their preventing effect on the development of several chronic diseases. The initial purpose of this report was to determine the effect of a hypercholesterolemic diet (HCD) given to mice, alone or with azoxymethane (AOM), on various obesity biochemical biomarkers, as well as on the induction of colon aberrant crypts (aberrant crypt foci; ACF). At the end of the 5-week assay, animals fed the HCD showed alterations in the level of total cholesterol, high- and low-density lipoproteins, and in the Atherogenic Index; besides, a significant elevation was observed in the number of ACF. Our second aim was to examine the effect of a Faba Protein Hydrolyzate (FPH) on mice fed the HCD. We first obtained protein hydrolyzates from the seeds of Vicia faba, determined the in vitro antioxidant potential with two tests, and, subsequently, evaluated the effect on obesity biomarkers and on the number of ACF. In the first case, we found that, generally, the best protective effect was obtained with the low dose of FPH (10 mg/kg) administered to animals fed the HCD, and injected AOM. With respect to the number of ACF, we observed that this dose was more effective, inhibiting such lesions to almost the level determined for the normocholesterolemic diet (NCD). Therefore, our results demonstrated the relevance of a HCD to develop anomalies in obesity biomarkers in mouse, as well as to increase the number of precarcinogenic lesions. Our results also showed a protective response with the administration of FPH, particularly with a specific dose, suggesting the need for extending research on the matter by widening the spectra of doses, in order to clearly define its potential to counteract the damage induced by the HCD, as well as to confirm if antioxidation in mice was involved in such an effect.
