1. Department of Statistics, Hunan Normal University College of Mathematics and Statistics, Changsha, Hunan, China
2. Department of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan, China
3. Department of Biochemistry and Molecular Biology, Jishou University School of Medicine, Jishou, Hunan, China
4. Department of Epidemiology and Health Statistics, Xiangya Public Health School, Central South University, Changsha, Hunan, China