About the Authors
Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
The authors have declared that no competing interests exist.
Conceived and designed the experiments: T-BZ Y-HQ. Analyzed the data: T-BZ L-NS F-YL W-FH Y-JZ. Wrote the paper: T-BZ. Checked the data in the paper: Y-HQ L-NS F-YL W-FH.