1. Department of Gastroenterology, General Hospital of Northern Theater Command (formerly General Hospital of Shenyang Military Area), Shenyang, China
2. Postgraduate College, Shenyang Pharmaceutical University, Shenyang, China
3. Department of Gastroenterology and Hepatology, Charité University Medical Center, Berlin, Germany
4. Department of Gastroenterology, General Hospital of Northern Theater Command (formerly General Hospital of Shenyang Military Area), No. 83 Wenhua Road, Shenyang, 110840 Liaoning Province, China