1. Department of Oncology, Jining No. 1 People's Hospital, Jining, Shandong 272011, P.R. China
2. Department of General Surgery, People's Hospital of Chiping, Chiping, Shandong 252100, P.R. China
3. First Ward, Department of Neurology, The Affiliated Central Hospital of Qingdao University, Qingdao, Shandong 266000, P.R. China
4. Department of Clinical Nutrition, People's Hospital of Zhangqiu Area, Jinan, Shandong 250200, P.R. China
5. Department of Respiratory Medicine, People's Hospital of Rizhao, Rizhao, Shandong 276826, P.R. China
6. Department of Respiratory Medicine, The Third People's Hospital of Qingdao, Qingdao, Shandong 266041, P.R. China