1. Food Safety Laboratory College of Food Science and Engineering Ocean University of China Qingdao 266003 China
2. Qingdao Municipal Center for Disease Control and Prevention 175 Shandong Road, Shibei District Qingdao Shandong Province 266033 China
3. General Surgery Ward 1 Qingdao Eighth People's Hospital 84 Fengshan Road, Licang District Qingdao Shandong Province 266100 China