Funding for this research was provided by:
Guandong Second Provincial General Hospital Youth Fund (YQ2016-007)
National Natural Science Foundation of China (81700512)
Received: 3 April 2018
Accepted: 29 June 2018
First Online: 3 August 2018
Ethics approval and consent to participate
: This research was approved by the ethics review board of Guangdong Second Provincial General Hospital. Written, informed consent was provided by each participant and/or their legal guardian.
: Not applicable.
: The authors declare that they have no competing interests.
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