Fast simultaneous determination of prominent polyphenols in vegetables and fruits by reversed phase liquid chromatography using a fused-core column

A reversed-phase high-performance liquid chromatography method with photodiode array detection has been developed enabling the joint determination of 17 prominent flavonoids and phenolic acids in vegetables and fruits. A multi-segmented gradient program using a fused-core column for the separation of several phenolic classes (phenolic acids and flavonoids) has been optimised. The influence of extraction conditions (sample freeze-drying, ultrasound extraction, solvent composition and extraction time) has been also optimised using response surface methodology with tomato samples as a model. Complete recoveries (76–108%) were obtained for the phenolic compounds present in tomato. The developed method provided satisfactory repeatability in terms of peak area (RSD < 2.9%) and retention time (RSD < 0.2%) both for standards and real samples. Detection limits ranged between 3 and 44 μg kg−1 for the detected polyphenols. This method is recommended for routine analysis of large number of samples typical of production quality systems or plant breeding programs

Relationship between suicidal thinking, anxiety, depression and stress in university students who are victims of cyberbullying

The objective of this study is to analyze the predictive capacity of cybervictimization with regards to suicidal thinking and anxiety, depression and stress in university students. The European Cyberbullying Intervention Project Questionnaire, the Depression Anxiety Stress Scale-21 and the Suicidality Scale were administered to a sample of 1282 university students (594 men and 688 women) aged between 18 and 46 (M = 21.65; SD = 4.25). The results suggest that being a cybervictim increases the probability of suicidal thinking and presenting high levels of anxiety, depression and stress. This study highlights the high prevalence rates of cyberbullying in the university environment and how this issue is associated with emotional problems and suicidal thinking. The identification of these relationships may allow for the development of effective preventive intervention measures to respond to this problem

Influence of photo-initiators in the preparation of methacrylate monoliths into poly(ethylene-co-tetrafluoroethylene) tubing for microbore HPLC

[EN] In this study, poly(butyl methacrylate-co-ethyleneglycol dimethacrylate) polymeric monoliths were in situ developed within 0.75 mm i.d. poly(ethylene-co-tetrafluoroethylene) (ETFE) tubing by UV polymerization via three different free-radical initiators fscce-azobisisobutyronitrile (AIBN), 2,2-dimethoxy-2-phenylacetophenone (DMPA) and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMPP). The influence of the nature of each photo-initiator and irradiation time on the morphological features of the polymer was investigated by scanning electron microscopy, and the chromatographic properties of the resulting microbore columns were evaluated using alkyl benzenes as test substances. The beds photo-initiated with MTMPP gave the best performance (minimum plate heights of 38 mu m for alkyl benzenes) and exhibited a satisfactory reproducibility in the chromatographic parameters (RSD < 11%). These monolithic columns were also successfully applied to the separation of phenylurea herbicides, proteins and a tryptic digest of beta-casein. (C) 2019 Elsevier B.V. All rights reserved.This research study has been sponsored by projects PROMETEO/2016/145 (Conselleria d'Educacio, Investigacio, Cultura i Esport, Generalitat Valenciana, Spain) and RTI2018-095536-B-I00 (Ministry of Science, Innovation and Universities, Spain).Catalá-Icardo, M.; Torres-Cartas, S.; Simó-Alfonso, EF.; Herrero-Martínez, JM. (2020). Influence of photo-initiators in the preparation of methacrylate monoliths into poly(ethylene-co-tetrafluoroethylene) tubing for microbore HPLC. Analytica Chimica Acta. 1093:160-167. https://doi.org/10.1016/j.aca.2019.09.055S160167109

Recanalization and rupture of a brain aneurysm completely occluded with a LEO stent nine years ago

We describe what is to our knowledge the first case of aneurysm regrowth and rupture after the nine years, of a complete occlusion of an aneurysm of the left middle cerebral treated of Leo Plus StentS

Evaluacion agronomica de los sustratos de cultivo

La finalidad de cualquier buen medio de cultivo es producir una planta decalidad en el más corto período de tiempo, con los más bajos costes de producción. En adición, la obtención y la eliminación del sustrato, una vez haya sido utilizado, no deberían provocar un impacto medioambiental de importancia. La evaluación agronómica de los sustratos de cultivo pasa por diferentes etapas. En primer lugar, debería procederse a la caracterización de los materiales, determinándose sus propiedades físicas, físico-químicas, químicas y biológicas. A continuación, dichas propiedades deberían estudiarse críticamente, comparándolas con las del sustrato "ideal". Posteriormente, y en aquellos casos en que las propiedades del material se desvíen significativamente de los valores óptimos recomendados, debería procederse a mejorar, de modo sencillo, dichas propiedades. Finalmente, deberían llevarse a cabo ensayos de crecimiento vegetal: ensayos en semilleros, ensayos en maceta, ensayos en condiciones de hidroponía y ensayos de enraizamiento de estacas. La realización de los ensayos de crecimiento bajo condiciones particulares (aire libre / invernadero, época del año, calidad de las aguas de riego, etc.) exige: 1) seleccionar las especies vegetales a utilizar como planta testigo, 2) diseñar las estrategias de manejo de los sustratos durante el ciclo de cultivo, especialmente los contenedores, el riego y la fertilización, y, 3) evaluar el crecimiento vegetativo y el desarrollo reproductivo mediante el control de los parámetros más adecuados a la hora de estimar la respuesta vegetal. Estos ensayos de crecimiento deberían incluir también sustratos comerciales como control de referencia

Musical input and reading fluency in the development of written skills in adult L2 Spanish learners

La música comparte propiedades con el lenguaje. A lo largo de los años se ha estudiado el vínculo entre ambas y su impacto en el aprendizaje de una L2. En el presente artículo nos centramos en estudiar el desarrollo de la expresión escrita y su relación con dos variables: la fluidez lectora y el input musical. Este pequeño estudio experimental se sitúa en el marco de la investigación en acción. La muestra estuvo compuesta por un total de 13 estudiantes de español de nivel B1, que se dividieron en dos grupos: uno de ellos recibió estímulo musical y el otro no. Asimismo, a ambos grupos se les facilitó un test de expresión escrita, basado en una actividad de Mario Rinvolucri, y un test de fluidez lectora oral. El estudio correlacional indica que es posible que haya una influencia positiva en el uso de la música como input añadido al texto escrito.Music shares characteristics with language. The link between both and their impact on second language learning has been studied over the years. In this paper we focus on studying the development of writing and its relation with two variables: reading fluency and musical input. This experimental study fits within an action-research framework. The sample used on this project consisted of 13 students of Spanish with a B1 level of language proficiency. The participants were divided into two groups, one of them received musical stimulation while the other did not. Additionally, both groups were given a writing test, based on an activity created by Mario Rinvolucri, along with an oral reading fluency test. The correlational study points out that there may be a positive effect on the use of music as input added to the written text

Accurate determination of the milk protein allergen β-lactoglobulin by on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry

An on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry (AA-SPE-CE-MS) method was developed to purify, preconcentrate, separate, and characterize the milk allergenic protein β-lactoglobulin (β-LG) in food samples. The sorbent to pack into the SPE microcartidges was prepared by immobilizing an aptamer against β-LG onto magnetic bead particles. After optimizing the SPE-CE-MS method, the sample (ca. 75 µL) was loaded in separation background electrolyte (BGE, 2 M acetic acid pH 2.2), while a solution of 100 mM NH4OH (pH 11.2) (ca. 100 nL) was used for the protein elution. The linearity of the method ranged between 0.1 and 20 µg·mL-1 and the limit of detection (LOD) was 0.05 µg·mL-1, which was 200 times lower than by CE-MS. The method was repeatable in terms of relative standard deviation (RSD) for migration times and peak areas (< 0.5 % and 2.4 %, respectively) and microcartridge lifetime was more than 25 analyses. The applicability of the method for the determination of low levels of β-LG was shown by analyzing milk-free foods (i.e. a 100 % cocoa dark chocolate, a hypoallergenic formula for infants, and a dairy-free white bread) and milk-containing white breads. Results were satisfactory in all cases, thus demonstrating the great potential of the developed method for accurate food safety and quality control

Simultaneous determination of main phenolic acids and flavonoids in tomato by micellar electrokinetic capillary electrophoresis

[EN] A methodology for the determination of tomato phenolic acids and flavonoids has been developed combining MEKC and DAD detection. The influence on polyphenol separation of pH and background electrolyte, BGE (borax, acetonitrile, methanol and SDS concentrations), was studied and optimized using response surface methodology and weighted desirability function. Separation of polyphenols was achieved within 20 min at 15 degrees C using 11.3 mM borax and 11.2 mM SDS adjusted to pH 8.5 as BGE. Validation was performed using standards and tomato extracts. Recoveries ranged from 77 to 106%. Acceptable repeatabilities were obtained for peak area (% RSD <3.1% and <3.7%) and migration times (% RSD <0.2% and <1.4%) for intra-and inter-day respectively. Detection limits ranged between 0.8 and 3.8 mg kg (1). Five and seven of these polyphenols were determined in samples of tomato and related species. This methodology will be valuable tool in breeding programs, analyzing a large number of samples. (C) 2016 Elsevier Ltd. All rights reserved.This study was partially supported by Project RTA2011-00062C04 funded by Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria. J.M. H-M expreses his thanks to the project CTQ2014-52765-R (MINECO of Spain and FEDER).Martí-Renau, R.; Valcárcel Germes, M.; Herrero-Martínez, JM.; Cebolla Cornejo, J.; Rosello Ripolles, S. (2017). Simultaneous determination of main phenolic acids and flavonoids in tomato by micellar electrokinetic capillary electrophoresis. Food Chemistry. 221:439-446. https://doi.org/10.1016/j.foodchem.2016.10.105S43944622