1. Institute of Biophysics and Department of Physics, Central China Normal University , Wuhan, 430079 , China
2. Department of Computer Science, Dartmouth College , Hanover, NH 03755 , USA
3. Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University , Wuhan 430071 , China
4. Department of Physics, The George Washington University , Washington, DC 20052 , USA