About the Authors
Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
University of California Los Angeles, School of Dentistry, Los Angeles, California, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: LJJ WL CYW. Performed the experiments: WL. Analyzed the data: WL LJJ CYW. Contributed reagents/materials/analysis tools: LJJ CYW. Wrote the paper: WL LJJ.