Funding for this research was provided by:
National Natural Science Foundation of China (81572952)
Received: 29 May 2018
Accepted: 20 September 2018
First Online: 25 September 2018
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of SAHZU, and was carried out in accordance with the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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