1. Department of Gastrointestinal Surgery, Yantai Yuhuangding Hospital, Yantai 264000, Shandong Province, China
2. Department of Surgical Care, Rizhao Hospital of Traditional Chinese Medicine, Rizhao 276800, Shandong Province, China
3. Health Management Center, Qingdao Fuwai Cardiovascular Hospital, Qingdao 266011, Shandong Province, China
4. Department of Emergency Surgery, Binzhou Medical University Hospital, Binzhou 256603, Shandong Province, China