1. Department of Gastroenterology; First Affiliated Hospital of China Medical University; Shenyang Liaoning China
2. Department of Geriatrics; First Affiliated Hospital of China Medical University; Shenyang Liaoning China
3. Department of Anatomy; Seirei Christopher College; Hamamatsu Japan
4. Guangdong Province Hospital for Occupational Disease Prevention and Treatment; Guangzhou Guangdong China