1. Department of Pediatrics, Yantai Affiliated Hospital of Binzhou Medical University, Yantai, Shandong 264100, P.R. China
2. Department of Biochemistry and Molecular Biology, Binzhou Medical University, Yantai, Shandong 264033, P.R. China
3. School of Rehabilitation Medicine, Binzhou Medical University, Yantai, Shandong 264033, P.R. China