1. Department of Pediatrics (II), People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China
2. Department of Child Health Care, The Third People's Hospital of Linyi, Linyi, Shandong 276000, P.R. China
3. Department of Spine Surgery, The Affiliated Central Hospital of Qingdao University, Qingdao Cancer Hospital, Qingdao, Shandong 266001, P.R. China
4. Electrocardiogram Room, The People's Hospital of Zhangqiu Area, Jinan, Shandong 250200, P.R. China
5. Department of Pathology, The People's Hospital of Zhangqiu Area, Jinan, Shandong 250200, P.R. China