About the Authors

Chao Wan

Affiliation State Key Laboratory of Tribology, Tsinghua University, Beijing, China

Zhixiu Hao

haozx@tsinghua.edu.cn (ZH); lenghj@bjmu.edu.cn (HL)

Affiliation State Key Laboratory of Tribology, Tsinghua University, Beijing, China

Shizhu Wen

Affiliation State Key Laboratory of Tribology, Tsinghua University, Beijing, China

Huijie Leng

haozx@tsinghua.edu.cn (ZH); lenghj@bjmu.edu.cn (HL)

Affiliation Department of orthopedics, Peking University Third Hospital, Beijing, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: CW ZH HL SW. Performed the experiments: CW HL. Analyzed the data: CW ZH. Contributed reagents/materials/analysis tools: CW HL. Wrote the paper: CW ZH HL.