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María Clara Verdi Constanza Melian Patricia Castellano Graciela Vignolo Mariana Blanco Massani 《International Journal of Food Science & Technology》2020,55(1):267-275
The effectiveness of antimicrobial mixtures against Listeria innocua 7, used as a L. monocytogenes surrogate, was investigated in broth and a food system. Synergistic effects were found for nisin (Nis), potassium sorbate (PS), calcium propionate (CP) and sodium lactate (SL), Nis + PS being the most effective binary mixture that exhibited listericidal activity in broth. To assess the effect of adding lactocin AL705 (AL705) to Nis + organic acid salt combinations, tridimensional isobolograms were generated. Sub-MIC combinations of the antimicrobials exerted bactericidal activity against L. innocua 7 after AL705 addition to the binary mixtures. However, when applied on Sardo cheese contaminated with L. innocua 7 (initial inoculum 4.45 ± 0.06 CFU g−1), only Nis + PS + AL705 produced count reductions respect to the control, reaching 3.04 ± 0.35 CFU g−1 counts after 15 days at 15 °C. Ternary combinations containing AL705 showed potential to reduce antimicrobial usages for L. innocua 7 inhibition. 相似文献
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Carmen Coya Constanza Ruiz Ángel Luis Álvarez Susana Álvarez-García Eva M. García-Frutos Berta Gómez-Lor Alicia de Andrés 《Organic Electronics》2012,13(10):2138-2148
We present a series of differently substituted star-shaped hexaaryltriindoles with tunable light-emitting properties. The deep blue emission is unchanged by donor peripheral substituents while an increasing acceptor character produces a reduction of the optical gap, an increased Stokes shift and eventually leads to the appearance of a new electronic level and to the simultaneous deep blue (413 nm) and green (552 nm) emission in solution. Quenching by concentration increases with the acceptor character but is lower as the tendency of these compounds to aggregate is stronger. Solution processed thin films present optical and morphological qualities adequate for device fabrication and similar electronic structure compared to solutions with an emission range from 423 nm up to 657 nm (red), demonstrating the possibility of tuning the energy levels by chemical functionalization. We have fabricated and characterized single-layer solution processed organic light emitting diodes (OLED) to investigate the influence on transport and emission properties of the substituting species. We analyzed the I–V response using a single-carrier numerical model that includes injection barriers and non-uniform electric-field across the layer. As a result, we obtained the electric field dependence of the mobility for each device. Best results are obtained on the most electron rich derivative functionalized with six donor methoxy groups. This material shows the highest emission efficiency in solid state, due to aggregation-induced enhancement, and better transport properties with the highest mobility and a very low turn-on voltage of 2.8 V. The solution processed OLED devices produce stable deep blue (CIE coordinates (0.16, 0.16)) to white (CIE coordinates (0.33, 0.3)) emission with similar luminous efficiencies. 相似文献
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López-Fontana CM Maselli ME de Di Nasso FE Telleria CM Carón RW 《Reproduction (Cambridge, England)》2011,142(3):477-485
Mifepristone (MIF) administration to cycling rats at proestrus induces hypersecretion of prolactin (PRL) at the following estrus. We aimed to assess whether this effect is due to the antiprogesterone or antiglucocorticoid action of MIF and to help underscore the nature of the circulating hormone(s) regulating PRL secretion at estrus. Female cycling rats in proestrus were treated with vehicle; the progesterone (Pg) and glucocorticoid receptor antagonists, MIF (5?mg/kg) or ORG-33628 (5?mg/kg); the glucocorticoid agonist dexamethasone (DEX; 27?mg/kg)±MIF; or the inhibitor of steroid synthesis aminoglutethimide (AG; 150?mg/kg)±MIF. The animals' blood was sampled the same day at 1800?h and at 1800?h of the following day to assess for circulating PRL and Pg levels. To distinguish antiglucocorticoid from antiprogesterone effects of MIF, we administered a highly specific neutralizing antibody against Pg. None of the antagonists modified serum PRL values at proestrus but increased PRL levels at estrus. DEX decreased the secretion of PRL at proestrus, yet the effect was entirely blocked by MIF. Furthermore, DEX decreased PRL at estrus in a MIF-reversible manner, suggesting that adrenal corticoids during proestrous may regulate PRL secretion at estrus. AG increased PRL secretion at estrus, whereas its association with MIF produced an even higher response. PRL concentration at estrus was not modified by the antiprogesterone antibody, suggesting that the effect of MIF is a consequence of its antiglucocorticoid effect and not due to its antiprogesterone properties. In conclusion, PRL secretion in the afternoon of the estrus is most likely regulated by glucocorticoids through an inhibitory action. 相似文献
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M Pan J Suárez de Lezo A Medina M Romero E Hernández J Segura F Melian F Wangüemert M Landin F Benítez M Amat F Velasco A Torres 《Canadian Metallurgical Quarterly》1997,80(10):1336-1338
Two hundred twenty-eight patients with successful coronary stent implantation were randomized either to protamine administration and femoral sheath removal (group I, n = 117) or no heparin neutralization and delayed sheath removal (group II, n = 111). The hospital stay after treatment was shorter in patients receiving protamine; therefore, protamine use for neutralizing circulating heparin may be safely administered immediately after stent implantation. 相似文献
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Alba García-Rodríguez Laura Vila Constanza Cortés Alba Hernández Ricard Marcos 《Particle and fibre toxicology》2018,15(1):33
Background
The biological effects of nanoparticles depend on several characteristics such as size and shape that must be taken into account in any type of assessment. The increased use of titanium dioxide nanoparticles (TiO2NPs) for industrial applications, and specifically as a food additive, demands a deep assessment of their potential risk for humans, including their abilities to cross biological barriers.Methods
We have investigated the interaction of three differently shaped TiO2NPs (nanospheres, nanorods and nanowires) in an in vitro model of the intestinal barrier, where the coculture of Caco-2/HT29 cells confers inherent intestinal epithelium characteristics to the model (i.e. mucus secretion, brush border, tight junctions, etc.).Results
Adverse effects in the intestinal epithelium were detected by studying the barrier’s integrity (TEER), permeability (LY) and changes in the gene expression of selected specific markers. Using Laser Scanning Confocal Microscopy, we detected a different behaviour in the bio-adhesion and biodistribution of each of the TiO2NPs. Moreover, we were able to specifically localize each type of TiO2NPs inside the cells. Interestingly, general DNA damage, but not oxidative DNA damage effects, were detected by using the FPG version of the comet assay.Conclusions
Results indicate different interactions and cellular responses related to differently shaped TiO2NPs, nanowires showing the most harmful effects.6.
The determination of chloride impurities in ionic liquids using ion chromatography is described. A wide range of cation-anion combinations may be analyzed using ion chromatography, including water-immiscible ionic liquids. For all ionic liquids studied, the limit of quantification for chloride was found to be below 8 ppm. 相似文献
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Nelson D. Rodríguez‐Marin Aylin A. Figueroa‐Chaverra Mayerly A. Snchez‐Jimnez Vanessa Orozco‐Orrego Constanza Bohrquez‐Orozco Omar R. García Magda I. Pinzn Leidy T. Snchez Cristian C. Villa 《Journal of texture studies》2019,50(2):148-154
Growing interest in processed frozen products with similar characteristics to natural products has generated the study of new products in the food industry field. The characteristics of each matrix, the process of elaboration, composition, and structure of the additives and the interactions amongst these modify the food's texture, structure, physical and sensory properties and, hence, interfere directly with consumer acceptance. This research studied the effect of adding cryoprotectors during frozen storage on the rheological, physicochemical, structural, and microbiological properties in a Mafafa‐quinoa‐olive oil puree. To carry out the study, the rheological properties were determined through dynamic oscillatory tests and in steady state; likewise, the physicochemical properties (humidity, color, pH, and syneresis) were analyzed. Regarding physicochemical properties, the humidity content in the purees formulated varied between 57 and 74%, without important variation (p > .05) with respect to the formulation, however, in the storage during the freezing/thawing process, this parameter diminished in greater proportion in those purees containing carrageenan as cryoconservant. Both the addition of cryoconservants and the storage time affected significantly (p < .05) the puree's syneresis, with the degree of exudation being lower in the formulation containing xanthan gum at 1% w/w. During the freezing/thawing process, decreased apparent viscosity was noted. Additionally, the analysis of the viscoelastic properties of the purees evidences that already described, given that a significant effect (p < .05) was observed of the formulation of purees in the elastic component G′, in contrast with a notable decrease in the viscous component G″. 相似文献