1. Department of Human Anatomy, Kangda College, Nanjing Medical University, Lianyungang, Jiangsu, China
2. Neonatal Medical Center, Children’s Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
3. The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, Jiangsu, China