Simulation-based mastery learning (SBML) for rapid acquisition of upper endoscopy knowledge and skills–initial observation oleh Tiffany Nguyen-Vu, BA, Carmel Malvar, BA, Yung Ka Chin, MD, Tonya Kaltenbach, MD, MS, Andy Liu, MD, Thomas Myint, MD, Ravishankar Asokkumar, MBBS, Amandeep Shergill, MD, MS, Roy Soetikno, MD, MS