1. Department of Respiratory Medicine, People's Hospital of Zhengzhou University, Zhengzhou, Henan 450000, P.R. China
2. Respiratory Department, The Affiliated Yantai Yuhuangding Hospital of Qingdao University Medical College, Yantai, Shandong 264000, P.R. China
3. Institute of Basic Theory of Traditional Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing 100700, P.R. China