1. General Surgery Department of Second Xiangya Hospital, Central South University, Changsha, HN, China
2. China State Key Laboratory for Powder Metallurgy, Central South University, Changsha, HN, China
3. Department of Histology and Embryology, Xiangya School of Medicine, Central South University, Changsha, HN, China
4. Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing, China
5. Department of Physics, University of Texas at Arlington, Arlington, TX, USA