1. CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing, China;
2. University of Chinese Academy of Sciences, Beijing, China;
3. School of Life Science, Beijing Institute of Technology, Beijing, China;
4. Sino-Danish College, University of Chinese Academy of Sciences, Beijing, P. R. China;
5. Center for Neuroscience Research, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian Province, China