1. The First Clinical Medical College, Lanzhou University, Lanzhou, Gansu Province, China
2. Department of Thoracic Surgery, the First Hospital of Lanzhou University, Lanzhou, Gansu Province, China
3. Qilu hospital of Shandong University, Shandong University, Jinan, Shandong province, China
4. School of Management, Lanzhou University, Lanzhou, Gansu Province, China
5. Gansu Province International Cooperation Base for Research and Application of Key Technology of Thoracic Surgery, The First Hospital of Lanzhou University, Lanzhou, Gansu Province, China.