1. Department of Orthopedics, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, P. R. China
2. Department of Gynecology, Hebei Medical University Second Affiliated Hospital, Shijiazhuang, Hebei, P. R. China
3. Department of Thoracic Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, P. R. China