1. Department
of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
2. Graduate
Program in Biophysics, Harvard University, Cambridge, Massachusetts 02138, United States
3. Biodynamic
Optical Imaging Center (BIOPIC), Peking University, Beijing 100871, P. R. China
4. Beijing
International Center for Mathematical Research (BICMR), Peking University, Beijing 100871, P. R. China