1. Departments of Poisoning and Occupational Diseases, Qilu Hospital, Shandong University, Jinan, Shandong, P.R. China;
2. Department of Intensive Care Medicine, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, P.R. China;
3. Public Health School of Shandong University, Jinan, Shandong, P.R. China