Evaluation of 13C-Phenylalanine Breath Test for the Measurement of Hepatocyte Function in Patients with Chronic Liver Disease Z.J. Bao 1 , D.K. Qiu 2,3 , X. Ma 2,3 , G.S. Zhang 1 , Y.Q. Huang 1 , Z.P. Fan 2,3 , S.M. Yin 1 1 Huadong Hospital, Fudan University, 2 Renji Hospital, Shanghai Jiao Tong University School of Medicine, 3 