1. Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
2. College of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
3. State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, P. R. China
4. Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China