Funding for this research was provided by:
Ministry of Science and Technology, Taiwan (MOST 105-2314-B-038-020, MOST 105-2314-B-038-019)
Received: 31 October 2017
Accepted: 2 May 2018
First Online: 18 May 2018
Ethics approval and consent to participate
: “Not applicable” (The present paper did not involve the use of any animal or human data).
: The authors declare that they have no competing interests.
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