Sheng, Ke
Article History
Received: 16 March 2018
Accepted: 26 March 2018
First Online: 13 April 2018
Ethics approval and consent to participate
: The study is approved by UCLA Internal Review Board (IRB) #12–001882.
: The letter shows the surfaces of a human subject (the author), who agrees to the publication of the letter.
: The author declares that he has no competing interests.
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