1. Department
of Chemistry, Universidad del Turabo, Carr. 189, Km 3.3, Gurabo, Puerto Rico 00778, United States
2. Department
of Electrical Engineering, Universidad del Turabo, Carr. 189, Km
3.3, Gurabo, Puerto Rico 00778, United States
3. Department
of Physiology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico 00936, United States