1. Department of General Practice, Xi’an Ninth Hospital , Xi’an , China
2. Department of Clinical Medicine, School of Queen Mary, Nanchang University , Nanchang , China
3. Department of Neurology, Xi’an Electric Power Central Hospital , Xi’an , China
4. Department of Endocrinology, Xijing Hospital, Air Force Medical University , 127 West Changle Road , Xi’an 710032 , China
5. Department of Microbiology and Pathogen Biology, Basic Medical School, Air Force Medical University , Xi’an , China
6. Department of Hepatobiliary Surgery, Xijing Hospital, Air Force Medical University , Xi’an , China