1. Department of Respiratory and Critical Care Medicine, The Second Hospital of Jilin University, Changchun 130021, P. R. China
2. Department of General Practice, The First Hospital of Jilin University, Changchun 130021, P. R. China
3. Department of Clinical Laboratory, The First Hospital of Jilin University, Changchun 130021, P. R. China
4. Department of Health Examination Center, The First Hospital of Jilin University, Changchun 130021, P. R. China