1. Department of Gastrointestinal Surgery, The Second Hospital of Shandong University, Jinan, Shandong, China (mainland)
2. Department of Electrocardiography, Peoples’ Hospital of Zhangqiu, Jinan, Shandong, China (mainland)
3. Department of General Surgery, Dezhou Peoples’ Hospital, Dezhou, Shandong, China (mainland)
4. Department of Oncology, Peoples’ Hospital of Zhangqiu, Jinan, Shandong, China (mainland)