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La inteligencia emocional ha pasado de ser un concepto novedoso e inicialmente cuestionado a constituirse en un elemento de especial interés para la comprensión de las diferencias individuales que pueden marcar la diferencia a la hora de alcanzar un buen desempeño académico o desarrollar competencias para la interacción y comunicación con los demás. Este estudio tuvo como objetivo determinar la relación entre inteligencia emocional y rendimiento académico, diferenciando entre sexo y tipología familiar en una muestra de 214 adolescentes escolarizados de la ciudad de Bucaramanga, Santander (Colombia). Los instrumentos utilizados fueron la ficha sociodemográfica, el Trait-Meta Mood Scale (TMMS-24) y el consolidado de notas. Los resultados mostraron una relación significativa entre el género y las dimensiones de inteligencia emocional, observándose puntuaciones más altas en las mujeres que en los hombres en la dimensión de percepción emocional, mientras éstos últimos presentaron puntuaciones más altas que las mujeres en la dimensión de regulación emocional. No se hallaron diferencias significativas entre estudiantes con familias nucleares, extensas y mononucleares o uniparentales. De otro lado, no se observó una relación significativa entre inteligencia emocional y rendimiento académico.

Aim: to provide a comprehensive frame of reference of knowledge management and organizational learning, its main definitions and knowledge management models. Results: day after day these subjects take a greater interest by organizations that should be making ongoing efforts to achieve their addressing, in search of competitive advantages and added value that those represent for their development. However, the review of the literature often analyzes these two constructs in an isolated way, without evidencing its due articulation between both organizational systems. Conclusion: it is paramount to generate facilitating processes of organizational learning through dynamic practices that prioritize human, organizational and relational capital, which act synergistically for the configuration of intelligent organizations to ensure their sustainability.

Here we developed a flow-based system resulting in improved performance of enzyme cascade-based biofuel cells. A paper-based biofuel cell with passive laminar flow was build to show the impact of flow on the performance of two different enzyme cascades – methanol and ethanol cascade. Both cascades demonstrated enhanced electrochemical output as a consequence of the decreased diffusion path of reaction intermediates identifying the intermediates diffusion in between enzymatic active sites as the rate limiting step in cascade operating systems.

The onset potential of an electrocatalytic reaction is frequently used as an indicator to compare the catalytic performance of electrocatalysts. However, in addition to the fact that the onset potential is an undefined physico-chemical value which is dependent on the sensitivity of the used potentiostat its determination using voltammetry at the catalyst-modified electrode surface may be superimposed by additional Faradaic reactions e.g. from redox conversions of the catalyst material or corrosion processes. Gas-evolving electrodes suffer additionally from the dynamics of gas bubble formation and departure leading to inherent limitations of voltammetric studies directly performed at the catalyst-modified electrode. Nanometer-sized electrodes accurately positioned by means of shearforce-based constant-distance mode SECM are proposed for the highly sensitive determination of the onset potential of microcavity electrodes filled with different perovskites as oxygen evolution catalysts. Double barrel microcavity electrodes are additionally suggested for the simultaneous investigation of two catalysts. They enable direct referencing of a catalyst with a benchmark catalyst material in a single experiment.

Different modification procedures to stabilize and control the orientation of Myrothecium verrucaria bilirubin oxidase (MvBOD) on 3D carbon nanotube/carbon microfiber-modified graphite electrode surfaces were evaluated for the development of biofuel-cell cathodes. The surface properties of different linkers for covalent binding of BOD were investigated by using atomic force microscopy-based techniques. For all immobilization strategies, the maximal current response was obtained at a pH value of 6.5 with temperatures between 20 and 35 °C. The biocathode based on MvBOD immobilized through an imino bond to the electrode showed the highest current density (1600 μA cm−2) and was resistant to the presence of chloride ions. A biofuel cell was constructed, and it exhibited a maximal power of 54 μW cm−2 at 350 mV with an open-circuit voltage of about 600 mV by using a cellobiose dehydrogenase based bioanode and glucose as the fuel.

Determination of the so-called onset potentials, i.e. the lowest (for the anodic reactions) or the highest (for the cathodic reactions) potentials at which a reaction product is formed at a given electrode and at defined conditions, is very important for the evaluation of the catalytic activity and even more for the comparison of different catalysts. We present an approach for the determination of the onset potentials based on scanning electrochemical microscopy (SECM) using the “substrate generation–tip collection” mode. In the proposed method, the potential applied to the catalyst sample is changed stepwise. A micro-electrode serving as SECM tip is positioned in known close proximity to the catalyst surface and is used to detect the onset of the formation of the product of the catalytic reaction, specifically gas generation at the sample surface. The oxygen evolution reaction (OER) at model RuO2 and perovskite catalyst surfaces is used to evaluate the approach. The suggested method is supposed to provide a clearer and sensitive means for the detection of the onset potentials of electrolytic gas evolution reactions as compared to conventional procedures which mainly use cyclic voltammetry on stationary or rotating (ring) disk electrodes. Moreover, the detection of the reaction product at the SECM tip allows distinguishing between parasitic reactions at the catalyst surface and the true formation of the anticipated reaction product. Keywords: Electrocatalysis, Electrochemical microscopy, Gas evolution, Microelectrodes, Oxygen evolution

High-quality graphene oxide (GO) with high crystallinity and electrical conductivity as well as in situ doped with nitrogen and sulfur is obtained via the electrochemical exfoliation of graphite. Furthermore, iron incorporated GO sheets show promising catalytic activity and stable methanol tolerance durability when used as electrocatalysts for the oxygen reduction reaction.

NAD + -dependent enzymes require the presence of catalysts for cofactor regeneration in order to be employed in enzymatic biofuel cells. Poly-(methylene green) catalysts have proven to help the oxidation reaction of NADH allowing for the use of such enzymes in electrocatalytic oxidation reactions. In this paper we present the development of 3D anode based on NAD + -dependent malate dehydrogenase. The 3D material chosen was reticulated vitreous carbon (RVC) which was modified with poly-(MG) for NADH oxidation and it also accommodated the porous immobilization matrix for MDH consisting of MWCNTs embedded in chitosan; allowing for mass transport of the substrate to the electrode. Scanning electron microscopy was used in order to characterize the poly-(MG)-modified RVC, and electrochemical evaluation of the anode was performed.

Electrochemically polymerized azines have been employed frequently as NADH electrocatalysts in biosensors and biofuel cells. However, some applications of these electrocatalysts do not lend themselves to electropolymerization. Therefore, this research investigates the chemical synthesis and application of poly(methylene blue) (PMB) and poly(methylene green) (PMG) in electrocatalysis. In an attempt to develop a simple synthesis for polymerized thiazines that could be immobilized on any surface, we investigated several polymerization protocols that are described in this paper. Structural analyses imply that the chemically synthesized polymers are chemically unique in comparison to the electropolymerized polymers. Amperometric investigations were used to compare the catalytic activity of chemically and electrochemically synthesized polymers as electrocatalysts for the oxidation of NADH and the chemically synthesized polymers were employed at the bioanode of a methanol/air biofuel cell to show their utility for this application.

Glucose oxidase catalyzes the formation of metallic gold particles in immediate proximity of the protein from gold (III) chloride in the absence of any other catalytic or reductive substrates. The protein-mediated gold reduction reaction leads to size-controllable gold particle formation and concomitant association of the enzyme in an electrically conductive metallic template. Such an enzyme immobilization strategy provides a simple and rapid method to create an intimate interface between glucose oxidase and a conductive matrix, which can be joined to an electrode surface. Model electrodes were prepared by entraining the glucose oxidase/gold particles onto carbon paper. Voltammetry of the resulting electrodes revealed stable oxidation and reduction peaks at a potential close to that of the standard value for the FAD/ FADH2 cofactor of immobilized glucose oxidase. The gold electrodes exhibit catalytic activity in the presence of glucose confirming the entrapment of active glucose oxidase within the gold architecture. The resulting composite material can be successfully integrated with electrodes of various designs for biosensor and biofuel cell applications.

NADH electrocatalysts have been an area of study for over 3 decades. Polyazines have been popular electrocatalysts of choice for NADH oxidation for both sensors and biofuel cell applications. However, little is known about the structure and function relationship between these polyazines and their ability for NADH oxidation. In this paper, we utilize XPS, SEM, and NMR to evaluate the structure of polyazines and relate that to their electrochemical properties.

This paper investigates the utility of ‘cross–lab’ comparative analysis of electrocatalytic electrode performance using standardized modular stack cells and test protocols. Using poly(methylene green)-modified glassy carbon electrodes as the model system, we characterized electrode fabrication and performance with respect to the catalytic oxidation of NADH at neutral pH and low overpotential. Three sets of experiments were duplicated across four independent laboratories and the experimental results from each set were analyzed and compared in terms of key electroanalytical parameters. Statistical analyses were performed at three distinct levels: 1) the standard deviation among repetitive cycles within an experiment; 2) the standard deviation among repetitive experiments in the same laboratory, and 3) the standard deviation among experiments performed across all four laboratories. Using predefined criteria of ‘reproducibility’ for each level, most parameters were found to be statistically reproducible at most levels. When a particular parameter was found to be irreproducible in a given level, commentary is given on how that information can be used diagnose what chemical/physical aspects of the process were uncontrolled or poorly understood and therefore candidates for future research. This exercise, which is presented as a ‘proof–of-principle’ step towards the concept of standardizing electrocatalytic evaluation, illustrates the importance of executing electrochemical characterization protocols across several labs and using fixed geometry and dimensions, system configuration, and applied electrochemical conditions. Future work is under way to extend these principles to systems with fluid flow.

This work demonstrates a new approach for building bio-inorganic interfaces by integrating biomimetically-derived silica with single-walled carbon nanotubes to create a conductive matrix for immobilization of enzymes. Such a strategy not only allows simple integration into bio-devices but presents an opportunity to intimately interface an enzyme and manifest direct electron transfer features. Biologically-templated silica/carbon nanotube/enzyme composites were evaluated electrochemically and characterized by means of X-ray photoelectron spectroscopy. Voltammetry of the composites displayed stable oxidation and reduction peaks at an optimal potential close to that of the FAC/FADS(sub 2) cofactor of immobilized glucose oxidase. The immobilization stabilized enzyme activity for a period of one month and retained catalytic activity towards the oxidation of glucose. It was demonstrated that the resulting composite can be successfully integrated into functional bio-electrodes for biosensor and biofuel cell applications.

The bacterially-expressed laccase, small laccase (SLAC) of Streptomyces coelicolor , was incorporated into electrodes of both direct electron transfer (DET) and mediated electron transfer (MET) designs for application in biofuel cells. Using the DET design, enzyme redox kinetics were directly observable using cyclic voltammetry, and a redox potential of 0.43 V (SHE) was observed. When mediated by an osmium redox polymer, the oxygen-reducing cathode retained maximum activity at pH 7, producing 1.5 mA/cm 2 in a planar configuration at 900 rpm and 40 °C, thus outperforming enzyme electrodes produced using laccase from fungal Trametes versicolor (0.2 mA/cm 2 ) under similar conditions. This improvement is directly attributable to differences in the kinetics of SLAC and fungal laccases. Maximum stability of the mediated SLAC electrode was observed at pH above the enzyme's relatively high isoelectric point, where the anionic enzyme molecules could form an electrostatic adduct with the cationic mediator. Porous composite SLAC electrodes with increased surface area produced a current density of 6.25 mA/cm 2 at 0.3 V (SHE) under the above conditions.

The incorporation of Fe-Nx/C moieties into perovskites remarkably activates them for the oxygen reduction reaction (ORR) and also leads to notable improvement of their activity towards the oxygen evolution reaction (OER) thus presenting a new route for realizing high performance, low cost bifunctional catalysts for reversible oxygen electrodes.

Cavity microelectrodes were used as a binder-free platform to evaluate oxygen evolution reaction (OER) electrocatalysts with respect to gas bubble formation and departure. Electrochemical noise measurements were performed by using RuO2 as a benchmark catalyst and the perovskite La0.58 Sr0.4 Fe0.8 Co0.2 O3 as a non-noble metal OER catalyst with lower intrinsic conductivity. Changes in the current during the OER originate from variations in electrolyte resistance during the formation of the gas phase and partial coverage of the active area. Fluctuations observed in current and conductance transients were used to establish the contribution from the ohmic overpotential and to determine the characteristic frequency of oxygen evolution. The proposed quantitative determination of gas bubble growth and departure opens up the route for a rational interface design by considering gas bubble growth and departure as a main contributing factor to the overall electrocatalytic activity at high current densities.

The oxygen evolution reaction (OER) is an enabling process for technologies in the area of energy conversion and storage, but its slow kinetics limits its efficiency. We performed an electrochemical evaluation of 14 different perovskites of variable composition and stoichiometry as OER electrocatalysts in alkaline media. We particularly focused on improved methods for a reliable comparison of catalyst activity. From initial electrochemical results we selected the most active samples for further optimization of electrode preparation and testing. An inverted cell configuration facilitated gas bubble detachment and thus minimized blockage of the active surface area. We describe parameters, such as the presence of specific cations, stoichiometry, and conductivity, that are important for obtaining electroactive perovskites for OER. Conductive additives enhanced the current and decreased the apparent overpotential of OER for one of the most active samples (La(0.58)Sr(0.4)Fe(0.8)Co(0.2)O(3)).

This research introduces a cavity anode design based on new single-walled nanotube (SWNTs) papers, "bucky" papers, used for the oxidation (and regeneration) of nicotinamide adenine dinucleotide (NADH) and the oxidation of l-malate. The materials designed are paper-like processed composites containing also additives: BP11 sample contains SWNTs and isopropanol (IPA); the BPMG sample contains SWNTs, IPA, and methylene green (MG). NADH/NAD(+) is the cofactor responsible for the oxidation of l-malate by malate dehydrogenase (MDH), in the Krebs' cycle. Because of the high overpotential of NADH oxidation, poly methylene green (PMG) was utilized as the electrocatalyst to produce NAD(+). The electrocatalyst was deposited on the surface of the "bucky" papers by electropolymerization by means of 10 voltammetric cycles in a range of -0.5 V and +1.3 V (vs Ag/AgCl reference electrode) at a scan rate of 5 mV/s. The catalytic performance of PMG was evaluated by chronoamperometric measurements of NADH oxidation at 0.3 V in phosphate buffer and l-malate oxidation at 0.1 V in the presence of MDH. For both "bucky" papers, the chronoamperometric curves of PMG, current vs NADH concentration, show a linear relationship demonstrating to have a first order Fick's law behavior for concentrations of NADH lower than 6 mM. The chronoamperometric curves in the presence of MDH, current against l-malate concentration, show a Michaelis-Menten behavior where no inhibition or competitive reaction are detected. Additionally, the anodic materials were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), the polymerization of MG is effectively observed in the form of particles nucleation. The anodes show an excellent electrocatalytic activity toward NADH oxidation. The electrode design is feasible, reproducible, and overall stable.

The main goal of this study is to determine the degree of agreement between the reports provided by parents and teachers about oppositional defiant symptoms in school children between the ages of 6 and 8 years. In addition, it attempts to determine whether children's age and sex affect the level of agreement between informants. Parents and teachers assessed 702 girls and boys at 25 schools in the Region of Osona, Barcelona (Spain) with the Child Symptom Inventory-4 (parents' and teachers' version). The results indicate a very low agreement -practically null- between the valuations of both informants; furthermore, no significant difference due to the variables age and sex of the children was observed in the above-mentioned valuations. The parents tended to appraise most of the symptoms of the Oppositional Defiant Disorder as present and to evaluate their severity as being more intense.

This research evaluates the response of job stress in 149 employees from the three offices of a courier company in eastern Colombia. The results show a moderate level of work stress with the presence of physiological symptoms, mainly associated to gastrointestinal problems, finding no differences in gender or marital status. Regarding organizational variables, a statistically significant correlation between the number of hours worked per week and stress level was found, unlike the hierarchical level variables and work place, where there was no correlation. La presente investigación evalúa la respuesta de estrés laboral en 149 colaboradores pertenecientes a las tres sedes de una empresa de mensajería del Oriente colombiano. Los resultados muestran un nivel moderado de estrés laboral con presencia de síntomas fisiológicos, principalmente asociados con problemas gastrointestinales, no hallándose diferencias en función del género, ni del estado civil. Con relación a las variables organizacionales, se encontró una correlación estadísticamente significativa entre el número de horas laboradas por semana y nivel de estrés, a diferencia de las variables nivel jerárquico y sede de trabajo, en las que no se halló dicha correlación.

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Here, we investigate the effect of the time constant on the ED of Au particles on RVC substrates. Potentiostatic ED was performed on two RVC samples with electrochemical accessible surface areas of 1.0 and 750 cm 2 . Progressive nucleation was observed on both substrates. At the same applied potentials, the large ohmic drop on the high surface area sample (750 cm 2 ) cannot be neglected and results in a significantly reduced nucleation density (∼30%) and a larger mean diameter. Knowledge of how the electrochemical cell time constant (resistance-capacitance time constant) affects particle coverage and size allows one to optimize ED conditions on substrates with high surface areas. The scaling of ED conditions is important for several technological applications.