About the Authors

Yunxia Gao

Affiliation Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China

Haiyan Li

Affiliation Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China

Jing Liu

jliu@mail.ipc.ac.cn

Affiliations Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JL. Performed the experiments: YXG. Analyzed the data: YXG HYL JL. Contributed reagents/materials/analysis tools: YXG JL. Wrote the paper: YXG JL.