1 Center for Respiratory Diseases; Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital; National Clinical Research Center for Respiratory Diseases, Beijing 100029; Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.
2 Center for Respiratory Diseases; Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital; National Clinical Research Center for Respiratory Diseases, Beijing 100029, China.