Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.|Department of Physiology, The University of Hong Kong, Pok Fu Lam, Hong Kong.|Department of Physics, University of South Florida, Tampa, Florida, United States of America.|Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America, Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.|Department of Physics, University of South Florida, Tampa, Florida, United States of America.