Received: 10 April 2017
Accepted: 14 January 2018
First Online: 31 January 2018
Ethics approval and consent to participate
: We had obtained approval for this study from our Institutional Review Board (approval no. 2012–0013), and all data were collected based on Institutional Review Board approval. The Institutional Review Board determined that it is not necessary to obtain the informed consent to conduct our research.
: Not applicable.
: The authors declare that they have no competing interests.
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