Hong-Lin Chen1, Yi-Ping Song2, Kun Liu3. 1. School of Public Health, Nantong University, Nantong City, Jiangsu Province, China. 2. School of Medicine, Nantong University, Nantong City, Jiangsu Province, China. 3. Department of Cardiac Surgery, Affiliated Hospital of Nantong University, Nantong City, Jiangsu Province, China.