Novel pathogenic WHRN variant causing hearing loss in a moroccan family

International audienceThe most prevalent sensory disease in humans is deafness. A variety of genes have been linked to hearing loss, which can either be isolated (non-syndromic) or associated with lesions in other organs (syndromic). It has been discovered that WHRN variants are responsible for non-syndromic hearing loss and Usher syndrome type II

As(V) sorption from aqueous solutions using quaternized algal/polyethyleneimine composite beads

International audienceComposite beads (APEI*), obtained by the controlled interaction of algal biomass with PEI, followed by ionotropic gelation and crosslinking processes using CaCl2/glutaraldehyde solution, provide efficient support for metal binding. The quaternization of algal/PEI beads (Q-APEI*) significantly increases the sorption properties of the composite beads (APEI*) for As(V). The materials are characterized by SEM/EDX, TGA, BET, elemental analysis, FTIR, XPS, and titration. The sorption of As(V) is studied in function of pH while sorption mechanism is discussed in function of metal speciation and surface characteristics of the sorbent. Optimum sorption occurs at pH close to 7. Fast uptake kinetics, correlated to textural properties are successfully fitted by pseudo-first order rate equation and the Crank equation (for resistance to intraparticle diffusion); equilibrium is reached with 45–60 min. The Langmuir equation finely fits sorption isotherms; maximum sorption capacity reaches 1.34 mmol As g−1. Arsenic can be completely eluted using 0.5 M CaCl2/0.5 M HCl solutions; the sorbent maintains high sorption and desorption efficiencies for a minimum of 5 cycles. The sorbent is tested for the removal of As(V) from mining effluents containing high concentration of iron and traces of zinc. At pH 3, the sorbent shows remarkable selectivity for As(V) over Fe. After controlling the initial pH to 5, a sorbent dosage of 2 g L−1 is sufficient for achieving the complete recovery of As(V) from mining effluent (corresponding to initial concentration of 1.295 mmol As L−1)