1. Department of Respiratory and Critical Care Medicine Aerospace Center Hospital Peking University Aerospace School of Clinical Medicine Beijing 100049 P. R. China
2. Department of Neurology Zhongnan Hospital of Wuhan University Wuhan 430000 P. R. China
3. Department of Neurology The Affiliated Hospital of Chifeng University Chifeng 024005 P. R. China
4. Chifeng University Health Science Center Chifeng 024000 P. R. China
5. Tianjin Medical University Cancer Institute and Hospital National Clinical Research Center for Cancer Tianjin's Clinical Research Center for Cancer Key Laboratory of Cancer Prevention and Therapy Tianjin 300060 P. R. China