1. Research Center School of Medicine of the UABJO-UNAM, Faculty of Medicine and Surgery, U.A.B.J.O, Oaxaca, Mexico
2. Division of Graduate Studies and Research, National Technological Institute of Mexico/IT.Oaxaca, Oaxaca, Mexico
3. CONAHCYT, Faculty of Medicine and Surgery, U.A.B.J.O, Oaxaca, Mexico