1. Department of General Surgery, Beijing Luhe Hospital, Capital Medical University, Beijing 101149, P.R. China
2. Central Laboratory Department, Beijing Luhe Hospital, Capital Medical University, Beijing 101149, P.R. China
3. Health Care Ward, Beijing Luhe Hospital, Capital Medical University, Beijing 101149, P.R. China
4. Department of Research and Development Center, John D. Dingell VA Medical Center, Detroit, MI 48201, USA