1. Department of Gastroenterology, The second hospital of Shandong University, 250033 Jinan, Shandong, China
2. Thyroid/Pancreatic surgery, The second hospital of Shandong university, 250033 Jinan, Shandong, China
3. Central Research Laboratory, The second hospital of Shandong University, 250033 Jinan, Shandong, China