Funding for this research was provided by:
National Basic Research Program of China (2013CB531503)
National Natural Science Foundation of China (81172789, 30972692)
Article History
Received: 25 December 2017
Accepted: 26 April 2018
First Online: 8 May 2018
Compliance with ethical standards
:
: The authors declare no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the Medical Ethics Committee of Shandong University and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study was approved by the Institutional Review Board of Shandong University.
: Informed consent was obtained from all individual participants and the parents of minor participant included in the study.