Funding for this research was provided by:
National Natural Science Foundation of China (81301603)
Text and Data Mining valid from 2018-03-27
Received: 13 July 2017
Accepted: 22 February 2018
First Online: 27 March 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board (IRB)/Independent Ethics Committee (IEC) of Nanjing Drum Tower Hospital (The Affiliated Drum Tower Hospital of Nanjing University Medical School) at Zhongshan Road 321, Nanjing 210,008, China. For the children, their parents or legal guardians have provided written informed consent on their behalf to take part in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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