Funding for this research was provided by:
National Institute of General Medical Sciences (P20GM103442)
Received: 2 April 2018
Accepted: 13 June 2018
First Online: 18 June 2018
Ethics approval and consent to participate
: This study was performed in accordance with the Declaration of Helsinki and was approved by the University of North Dakota IRB under IRB-201407-036. Consent to participate is not applicable for this study, because this is publicly available, existing data.
: Not applicable.
: The authors declare that they have no competing interests.
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