John Ong1, Yock Young Dan2, Jenny G Low3. 1. Department of Engineering, Materials Engineering & Materials - Tissue Interactions Group, University of Cambridge, Cambridge, UK; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; East of England Deanery, Gastroenterology Specialty Training Programme, Cambridge, UK. 2. Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. 3. Department of Infectious Diseases, Singapore General Hospital, Singapore; Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore.