1. School of Basic Medicine Sciences, Shandong Second Medical University, Weifang, Shandong 261053, P.R. China
2. Central Laboratory of The First Affiliated Hospital, Shandong Second Medical University, Weifang, Shandong 261000, P.R. China
3. Department of Spine Surgery, The 80th Group Army Hospital of Chinese PLA, Weifang, Shandong 261021, P.R. China