Comparison of efficacy and safety of the new generation helixone dialyzers Francisco Maduell; José Jesús Broseta; Diana Rodríguez-Espinosa; Lida María Rodas; Miquel Gómez; Marta Arias-Guillén; Néstor Fontseré; Manel Vera; Maria del Carmen Salgado; Nayra Rico; Rosa Ramos;