Ouyang, Peng http://orcid.org/0000-0003-0054-3219
Sun, Wenjun
Article History
Received: 19 April 2018
Accepted: 26 August 2018
First Online: 5 September 2018
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The study was approved by the Institutional Review Board of Peking University with ethical approval no. (IRB00001052-11014).
: Informed consent was obtained from all individual participants included in the study.
: The authors declare that they have no competing interests.
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