Study protocol and rationale of the “Cogniaction project” a cross-sectional and randomized controlled trial about physical activity, brain health, cognition, and educational achievement in schoolchildren

Background: Education and health are crucial topics for public policies as both largely determine the future wellbeing of the society. Currently, several studies recognize that physical activity (PA) benefits brain health in children. However, most of these studies have not been carried out in developing countries or lack the transference into the education field. The Cogni-Action Project is divided into two stages, a cross-sectional study and a crossover-randomized trial. The aim of the first part is to establish the associations of PA, sedentarism, and physical fitness with brain structure and function, cognitive performance and academic achievement in Chilean schoolchildren (10–13 years-old). The aim of the second part is to determinate the acute effects of three PA protocols on neuroelectric indices during a working memory and a reading task. Methods: PA and sedentarism will be self-reported and objectively-assessed with accelerometers in a representative subsample, whilst physical fitness will be evaluated through the ALPHA fitness test battery. Brain structure and function will be assessed by magnetic resonance imaging (MRI) in a randomized subsample. Cognitive performance will be assessed through the NeuroCognitive Performance Test, and academic achievement by school grades. In the second part 32 adolescents (12–13 year-old) will be cross-over randomized to these condition (i) “Moderate-Intensity Continuous Training” (MICT), (ii) “Cooperative High-Intensity Interval Training” (C-HIIT), and (iii) Sedentary condition. Neuroelectric indices will be measures by electroencephalogram (EEG) and eye-tracking, working memory by n-back task and reading comprehension by a reading task

Procesos de Oxidación avanzada en el tratamiento de agua

A lo largo de este libro diversos autores especializados exponen el tema permitiendo al lector encontrar desde principios básicos, hasta aplicaciones de procesos, resultando ser una fuente de consulta con una visión amplia de los procesos de oxidación avanzada y sus aplicaciones dentro del tratamiento de agua.El agua es un líquido vital, sin ella no podemos subsistir. Además de usarla en nuestro hogar, se utiliza en gran variedad de procesos industriales para la transformación de materias primas en productos terminados. El agua usada industrialmente cambia su composición fisicoquímica, ya que agregamos un sinfín de compuestos orgánicos e inorgánicos. Por ello, es necesario desarrollar nuevas metodologías que permitan de manera segura y eficiente recuperar la calidad del agua usada originalmente para poder usarla.Universidad Autónoma del Estado de Méxic

Synthesis and characterization of sb2o5-doped ti/sno2-iro2 anodes toward efficient degradation tannery dyes by in situ generated oxidizing species

Nowadays, the increasing pollution of natural water effluents with textile dyes is an emerging problem that has not received attention enough. This work presents a study on the preparation of two Ti/IrO2-SnO2-Sb2O5 electrodes so-called E1 and E2 with 0.01 and 0.09 wt% of Sb dopant, respectively, by the Pechini method. The characteristics of these electrodes were analyzed by scanning electron microscopy-energy dispersive X-ray spectroscopy and X-ray diffraction. The E2 anode possessed a higher electroactivity and produced more largely hydroxyl radicals in electrochemical oxidation (EO). The action of this oxidant, along with active chlorine of textile dyes like Violet RL, Green A and Brown DR was assessed in 50 mM Na2SO4 and 10 mM NaCl at pH 3.0 by EO with the E2 anode. It was found that the discoloration of 80 mg L−1 of each individual solution was enhanced with increasing the current density from 25 to 50 mA cm−2, always obeying a pseudo-first-order kinetics. The process was faster in the sequence: Green A 86% of color was attained in only 6 min. A mixture with 80 mg L−1 of each dye was treated under analogous EO conditions, giving rise to 100% discoloration in 20 min and about 90% chemical oxygen demand removal in 60 min at 50 mA cm−2

Electrochemical polymerization, characterization and in-situ conductivity studies of poly-3,4-ortho-xylendioxythiophene (PXDOT)

The electrochemical polymerization of 3,4-ortho-xylendioxythiophene (XDOT) in acetonitrile on Pt electrode let to obtain stable and well-adhered conducting polymer films. The voltamperometric response of the poly-3,4-ortho-xylendioxythiophene (PXDOT) showed a mirror-image, indicating fast electron transfer (ΔEp = 60 mV), which is a rare phenomenon in thick layers of conducting polymers. The in-situ electrochemical conductance experiments showed that the maximal conductance for PXDOT is reached at lower potentials and with less hysteresis than the observed for PEDOT, confirming a fast electrochemical response of the polymer. This behavior could be attributed to the presence of the xylen-unit attached to the polymer chain, which generates an internal order on the oligomeric chains, forming channels that facilitate the mobility of the electrolyte ions during the charge/discharge processes. Additionally, PXDOT showed an irreversible cathodic process which does not correspond to an n-doping, nevertheless induce a polymer internal rearrangement, which causes a major change in the p-doping signal. This cathodic process thus, it was attributed to the reduction of intrachain charge-trapped that was produced during electropolymerization

Evaluación de electrodos de diamante dopado con boro en la determinación de Cd(ll), Pb(ll) y Hg(ll) en aguas residuales mineras (Portovelo – Zaruma, Provincia de El Oro, Ecuador)

Reportamos un método para la determinación simultánea de Cd(II) y Pb(II), y Hg(II) en aguas residuales mineras, mediante Voltamperometría de Redisolución Anódica de Onda Cuadrada; sobre electrodo de Diamante dopado con boro. El electrodo se caracterizó por Microscopía de Fuerza Atómica y Espectroscopia Raman. Los límites de detección obtenidos para los iones Cd (II), Pb (II) y Hg (II) fueron 0,79 µg L-1, 2,13 µg L-1 y 2,01 µg L-1, respectivamente. La exactitud del método se determinó mediante la detección de los iones en un material de referencia certificado (Ref. IAEA-407, International Atomic Energy Agency). La prueba t-Student, demostró que no existe diferencia estadísticamente significativa entre la concentración certificada y la encontrad

Electrical communication between “Horseradish Peroxidase” and modified electrodes with nanomaterials: application as enzymatic electrochemical biosensors

In this compilation, the authors discuss the commercial source for the enzyme horseradish peroxidase, the tuberous roots of the horseradish plant which is native to the temperate regions of the world. Horseradish peroxidase is an oxidoreductase belonging to the highly ubiquitous group of peroxidases, indicating that this enzyme came into existence in the early stages of evolution and has been conserved thereafter. Following this, the authors discuss the latest advancements and innovations in the field of enzymatic electrochemical sensors based on the electrical communication between horseradish peroxidase and the enzyme’s modified electrodes surfaces. In conclusion, the authors discuss the potential for horseradish peroxidase use in colored wastewater treatment. C. I. Acid Violet 109 was used as a model dye in order to examine the feasibility of horseradish peroxidase application in the removal of anthraquinone class of synthetic dyes. The reaction conditions were optimized in terms of dye, enzyme and H2O2 concentration as well as temperature and pH influence.29-10

Fate, eco-toxicological characteristics, and treatment processes applied to water polluted with glyphosate: A critical review

Glyphosate is the most widely used active ingredient of Glyphosate Based Herbicides (GBHs), and which has environmental mobility towards water by its physicochemical characteristics. These properties determine its low availability in living organisms (log Kow 90%), depending on operational conditions, and without generation of intermediate metabolites. Moreover, new strategies (electrochemical) will avoid the hazardous waste production. Other combined processes (biological + physicochemical) will also reach glyphosate efficiencies removal above 90% but needing large spaces. However, their physical characteristics would make them feasible to be applied in agricultural areas

Electrochemical dopamine sensor using a nanoporous gold microelectrode: a proof-of-concept study for the detection of dopamine release by scanning electrochemical microscopy

Nanoporous gold (NPG) structures were prepared on the surface of a gold microelectrode (Au-μE) by an anodization-reduction method. Cyclic voltammetry and field emission scanning electron microscopy were used to study the electrochemical properties and the morphology of the nanostructured film. Voltammetry showed an improved sensitivity for dopamine (DA) oxidation at this microelectrode when compared to a bare gold microelectrode, with a peak near 0.2 V (vs. Ag/AgCl) at a scan rate of 0.1 V s−1. This is due to the increased surface area and roughness. Square wave voltammetry shows a response that is linear in the 0.1–10 μmol L−1 DA concentration range, with a 30 nmol L-1 detection limit and a sensitivity of 1.18 mA (μmol L−1)−1 cm−2. The sensor is not interfered by ascorbic acid. The reproducibility, repeatability, long-term stability and real sample analysis (spiked urine) were assessed, and acceptable performance was achieved. The “proof-of-concept” detection of dopamine release was demonstrated by using scanning electrochemical microscopy (SECM) with the aim of future applications for single cell analysis

Electrooxidación en procesos de oxidación avanzada para el tratamiento de agua residual

La electrocatálisis puede ser definida como la catálisis heterogénea de una reacción electroquímica, la cual ocurre en la interface electrodo–electrolito y donde el electrodo juega el doble rol de donador/aceptor de electrones y de catalizador (Sun S. G. et al., 2007). Un electrodo actúa como un catalizador de las reacciones, ya que participa ya sea aportando sitios para la adsorción de intermediarios (Mecanismo de Transferencia Interna) o bien como un transportador de electrones que transfiere la carga por efecto túnel a especies en la interfase (Mecanismo de Transferencia Externa). Esta disciplina estudia las reacciones electroquímicas que ocurren a un mismo valor de sobrepotencial, pero que sucede con velocidades diferentes dependiendo del material de electrodo como efecto de la catálisis. La diferencia en la función trabajo del material y la energía de interacción entre este y el compuesto a transformar es determinada por la constante heterogénea de transferencia electrónica (k°) (Munichandraiah, 2010).153-19

Electrochemical determination of lead in human blood serum and urine by anodic stripping voltammetry using glassy carbon electrodes covered with Ag–Hg and Ag–Bi bimetallic nanoparticles

The evaluation and application of glassy carbon electrodes modified with bimetallic nanoparticle deposits of Ag–Hg and Ag–Bi for determination of Pb(II) is described. Deposition of the nanostructured bimetallic combinations on top of the glassy carbon (GC) substrate, previously covered with a Nafion (Nf) film, resulted in electrodes with substantially enlarged hydrogen evolution over-voltage. As indicated by scanning electron microscopy and atomic force microscopy images, most of the deposited nanoparticles, with an average size of 150 nm, were uniformly dispersed inside the Nafion net while a smaller amount remained on top of the embedded ones. Sensitivity tests of the AgBiNpNf/GC modified electrode produced a detection limit (DL), based on the 3s criterion, of 0.66 μg L−1 and 0.24 μg L−1 for the AgHgNpNf/GC electrode. Accuracy was assessed by comparison with quantification of Pb(II) in human blood serum and urine samples analyzed by atomic absorption spectrometry, using a continuous source high resolution atomic absorption spectrometer