1. Department of Respiratory Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116000, P.R. China
2. Department of Geriatrics, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116000, P.R.�China
3. Department of Geriatrics, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116000, P.R. China
4. Department of Dermatology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116000, P.R.�China