1. Department of Intervention, Qinghai University Affiliated Hospital, Xining, Qinghai 810000, P.R. China
2. Department of Respiratory Medicine, Zaozhuang Mining Group Central Hospital, Zaozhuang, Shandong 277000, P.R. China
3. Department of Thoracic Surgery, Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning 116000, P.R. China