1. Department
of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan
2. Biomedical
Science Institute, Universidad Autonoma de Cd. Juárez, Estocolmo y anillo envolvente del PRONAF, Juárez Chih. CP 32315, Mexico