Received: 8 November 2017
Accepted: 11 February 2018
First Online: 14 February 2018
Ethics approval and consent to participate
: All procedures performed in this study were in accordance with the ethical standards of the Biomedical Research Ethics Committee at the University of Medicine and Pharmacy Ho Chi Minh city, Vietnam (Approval number: 156/DHYD-HD, dated 10/05/2017). Written informed consent was obtained from all individual participants included in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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