Analysis of polymeric phenolics in red wines using different techniques combined with gel permeation chromatography fractionation

A multiple-step analytical method was developed to improve the analysis of polymeric phenolics in red wines. With a common initial step based on the fractionation of wine phenolics by gel permeation chromatography (GPC), different analytical techniques were used: high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-mass spectrometry (MS), capillary zone electrophoresis (CZE) and spectrophotometry. This method proved to be valid for analyzing different families of phenolic compounds, such as monomeric phenolics and their derivatives, polymeric pigments and proanthocyanidins. The analytical characteristics of fractionation by GPC were studied and the method was fully validated, yielding satisfactory statistical results. GPC fractionation substantially improved the analysis of polymeric pigments by CZE, in terms of response, repeatability and reproducibility. It also represented an improvement in the traditional vanillin assay used for proanthocyanidin (PA) quantification. Astringent proanthocyanidins were also analyzed using a simple combined method that allowed these compounds, for which only general indexes were available, to be quantified. © 2005 Elsevier B.V. All rights reserved

An unusual interplay among disorder, Kondo-effect and spin-glass behavior in the Kondo lattices, Ce2_2Au1−x_{1-x}Cox_xSi3_3

We report the results of magnetic measurements for the solid solution Ce$_2$Au$_{1-x}$Co$_x$Si$_3$. The results reveal that this solid solution is characterized by a magnetic phase diagram (plot of magnetic transition temperature versus $x$) unusual for Kondo lattices. In particular, the spin-glass freezing induced by disorder is observed only for the compositions at the weak coupling limit; as one approaches the quantum critical point by a gradual replacement of Au by Co, this disorder effect is surprisingly suppressed in favor of long range antiferro-magnetic ordering in contrast to expectations. This unusual interplay between disorder, spin-glass freezing and the Kondo-effect calls for further refinement of theories on competition between magnetism and the Kondo effect.Comment: 4 pages, 3 figure

Tratado de topografia

Contiene: Vol. I:[Planimetría]. -- VII, 657 p. -- Vol. II: [Nivelación]. -- VII, 501, XXV -- Vol. III: Tomo I, Atlas ( 60 lám.) y Tomo II, Atlas (34 lám). -- 21x31 c

Beneficios con lavado, honey y natural de granos de Coffea arábica L. variedad catimor en la calidad física y organoléptica, Satipo - Perú

The objective was to compare the yield and quality of the Coffea arabica catimor variety processed with three beneficiation methods: honey, washed and natural. After harvesting, the grains were selected and floated to remove impurities. In the washing mill, the grains were pulped, fermented, washed and dried for three and a half days; In the honey mill, the procedure was similar to the previous one with the difference that the grains were not subjected to fermentation or washing; the drying was for eight days. In the natural method, after the float test, the grains were dried in the environment for 15 days. The results indicate that in the physical yield of the coffee beans with the washing method 80.83% was achieved, with the honey method 75.19% and 47.33% of exportable coffee through the natural method. In the analysis of the organoleptic quality in the natural method it was achieved: fragrance or aroma (7.83); flavor (7.83); aftertaste (7.61) acidity (7.81); body (7.83); balance (7.78) and appreciation (7.75) points significantly higher than the other treatments. Regarding the variables uniformity, clean cup and sweetness, the data were similar in the three methods.El objetivo fue comparar el rendimiento y la calidad de los granos de Coffea arabica variedad catimor procesados con tres métodos de beneficio: honey, lavado y natural. Después de la cosecha los granos fueron seleccionados y puestos a prueba de flote para separar las impurezas. En el beneficio de lavado, los granos fueron despulpados, fermentados, lavados y secados durante tres días y medio; en el beneficio honey, el procedimiento fue similar al anterior con la diferencia de que los granos no se sometieron a la fermentación ni al lavado; el secado fue por ocho días. En el método natural después de la prueba de flote los granos fueron secados en medio ambiente durante 15 días. Los resultados indican que en el rendimiento físico de los granos de café con el método de lavado se logró 80,83%, con el método honey 75,19% y mediante el método natural 47,33% de café exportable. En el análisis de la calidad organoléptica en el método natural se logró: fragancia o aroma (7,83); sabor (7,83); post gusto (7,61) acidez (7,81); cuerpo (7,83); balance (7,78) y apreciación (7,75) puntos significativamente mayores que los otros tratamientos. En cuanto a las variables uniformidad, taza limpia y dulzura los datos fueron similares en los tres métodos

Perhalophenyl Three-Coordinate Gold(I) Complexes as TADF Emitters : A Photophysical Study from Experimental and Computational Viewpoints

We report the synthesis of novel perhalophenyl three- coordinated gold( I) complexes using 1,2- bis-(diphenylphosphino)benzene (dppBz) as the chelating ligand and [AuR(tht)] (R = C6F5, C6Cl2F3, C6Cl5) as the perhalophenyl-gold(I) source, leading to [AuR(dppBz)] (R = C6F5 (1), C6Cl2F3 (2), C6Cl5 (3)) complexes. The solid-state structures of compounds 2 and 3 consist of discrete three-coordinated Au(I) complexes, which show a distorted trigonal planar geometry for the gold center with dissimilar Au-P distances. The distorted structural arrangement is closely related to its photophysical properties. The studied complexes display very intense emissions at room temperature (RT) and at 77 K in the solid state. Studies of the emissive properties of the complexes at different temperatures suggest that the emissions are phosphorescent at 77 K and exhibit thermally activated delayed fluorescence (TADF) at RT. First-principle calculations of the photophysical processes yielded rate constants for intersystem crossing and reverse intersystem crossing that are in excellent agreement with experimental data.Peer reviewe

Overexpression of the ATPase Inhibitory Factor 1 Favors a Non-metastatic Phenotype in Breast Cancer

Partial suppression of mitochondrial oxidative phosphorylation and the concurrent activation of aerobic glycolysis is a hallmark of proliferating cancer cells. Overexpression of the ATPase inhibitory factor 1 (IF1), an in vivo inhibitor of the mitochondrial ATP synthase, is observed in most prevalent human carcinomas favoring metabolic rewiring to an enhanced glycolysis and cancer progression. Consistently, a high expression of IF1 in hepatocarcinomas and in carcinomas of the lung, bladder, and stomach and in gliomas is a biomarker of bad patient prognosis. In contrast to these findings, we have previously reported that a high expression level of IF1 in breast carcinomas is indicative of less chance to develop metastatic disease. This finding is especially relevant in the bad prognosis group of patients bearing triple-negative breast carcinomas. To investigate the molecular mechanisms that underlie the differential behavior of IF1 in breast cancer progression, we have developed the triple-negative BT549 breast cancer cell line that overexpresses IF1 stably. When compared to controls, IF1-cells partially shut down respiration and enhance aerobic glycolysis. Transcriptomic analysis suggested that migration and invasion were specifically inhibited in IF1-overexpressing breast cancer cells. Analysis of gene expression by qPCR and western blotting indicate that IF1 overexpression supports the maintenance of components of the extracellular matrix (ECM) and E-cadherin concurrently with the downregulation of components and signaling pathways involved in epithelial to mesenchymal transition. The overexpression of IF1 in breast cancer cells has no effect in the rates of cellular proliferation and in the cell death response to staurosporine and hydrogen peroxide. However, the overexpression of IF1 significantly diminishes the ability of the cells to grow in soft agar and to migrate and invade when compared to control cells. Overall, the results indicate that IF1 overexpression despite favoring a metabolic phenotype prone to cancer progression in the specific case of breast cancer cells also promotes the maintenance of the ECM impeding metastatic disease. These findings hence provide a mechanistic explanation to the better prognosis of breast cancer patients bearing tumors with high expression level of IF1.CN-T and IM-R were supported by pre-doctoral FPI-MEC and JAE-CSIC fellowships, respectively. This work was supported by grants from the Ministerio de Economía y Competitividad (SAF2013-41945-R; SAF2016-75916-R), Comunidad Madrid (S2011/BMD-2402), and Fundación Ramón Areces 2015, Spain.Peer reviewedPeer Reviewe

Aptamers against live targets: Is in vivo SELEX finally coming to the edge?

Targeted therapeutics underwent a revolution with the entry of monoclonal antibodies in the medical toolkit. Oligonucleotide aptamers form another family of target agents that have been lagging behind in reaching the clinical arena in spite of their potential clinical translation. Some of the reasons for this might be related to the challenge in identifying aptamers with optimal in vivo specificity, and the nature of their pharmacokinetics. Aptamers usually show exquisite specificity, but they are also molecules that display dynamic structures subject to changing environments. Temperature, ion atmosphere, pH, and other variables are factors that could determine the affinity and specificity of aptamers. Thus, it is important to tune the aptamer selection process to the conditions in which you want your final aptamer to function; ideally, for in vivo applications, aptamers should be selected in an in vivo-like system or, ultimately, in a whole in vivo organism. In this review we recapitulate the implementations in systematic evolution of ligands by exponential enrichment (SELEX) to obtain aptamers with the best in vivo activity