The present work describes the study of mercury Hg(II) and lead Pb(II) removal in single and binary component systems into easily prepared chitosan-iron(III) bio-composite beads. Scanning electron microscopy and energy-dispersive X-ray (SEM-EDX) analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and point of zero charge (pHpzc) analysis were carried out. The experimental set covered pH study, single and competitive equilibrium, kinetics, chloride and sulfate effects as well as sorption–desorption cycles. In single systems, the Langmuir nonlinear model fitted the experimental data better than the Freundlich and Sips equations. The sorbent material has more affinity to Hg(II) rather than Pb(II) ions, the maximum sorption capacities were 1.8 mmol·g−1 and 0.56 mmol·g−1 for Hg(II) and Pb(II), respectively. The binary systems data were adjusted with competitive Langmuir isotherm model. The presence of sulfate ions in the multicomponent system [Hg(II)-Pb(II)] had a lesser impact on the sorption efficiency than did chloride ions, however, the presence of chloride ions improves the selectivity towards Hg(II) ions. The bio-based material showed good recovery performance of metal ions along three sorption–desorption cycles.

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Dentro del sistema de obtención de licencias en el Ecuador, los conductores van adquiriendo progresivamente habilidades que les permiten utilizar vehículos de mayor complejidad conforme avanza su capacitación. Bajo esta modalidad, se sobreentiende lógicamente que un conductor de vehículos pesados sabe conducir toda la gama de vehículos que están por debajo de éste. Sin embargo, el COIP sanciona como contravención la conducción de vehículos con licencias diferentes a las necesarias, cuando lo correcto sería el uso de licencias inferiores a la necesaria. En este contexto se realizó este estudio descriptivo tipo revisión documental con enfoque cualitativo, que tiene como objetivo analizar la falta de regulación del incorrecto uso de licencias de conducir en el Ecuador; en su cumplimiento se aplicaron los métodos: exegético, revisión bibliográfica y revisión documental, así como la técnica de análisis de contenido, lo que permitió analizar los principales cuerpos normativos del ordenamiento jurídico ecuatoriano que regulan la materia de tránsito, concluyendo que el sistema normativo ecuatoriano en materia de tránsito es completo y complejo, pero necesita de pequeñas reformas para así lograr un mejor cumplimiento y respeto de las leyes de tránsito.

The behavior of potassium ion (K+) establishes the repolarization and hyperpolarization states in the cell membrane of trabecular meshwork cells. One of the main proteins that controls this ion is calcium-dependent potassium maxi-channels BKca, their malfunction evoked by tyrosine kinases, destabilize the control of aqueous humor flow and the increase of intraocular pressure, responsible of glaucoma. In the present work, the ionic behavior of ion K+ of trabecular cells is detailed, when genistein and tyrphostin-51 are applied in culture cells. The flow behavior is described by means of mathematical expressions based on exponential functions and equations of line. Genistein and tyrphostin-51 drugs are compared in their efficiency of inhibiting tyrosine kinases from the mathematical functions provided by the proposed method. The present study describes the ion behavior regarding K+ potassium which is controlled by maxi-channels BKca that come from trabecular meshwork when genistein and tyrphostin-51 are applied in culture cells. The behavior of this flow is described by mathematical expressions. Thus, inhibitor drugs effect and characteristic time behavior are compared using their mathematical function.