1 Department of Respiratory and Critical Care Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
2 State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
3 Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China.
4 Department of Cardiology, Gansu Provincial Hospital, Lanzhou, China.
5 Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, San Diego, CA, United States.