Received: 7 November 2017
Accepted: 14 June 2018
First Online: 2 July 2018
Ethics approval and consent to participate
: A written informed consent was obtained from each participant in this study or from one of his family members, and the study was approved by the local ethical committee in Faculty of Medicine, Cairo University, in 28-9-2010.
: Not applicable
: The authors declare that they have no competing interests.
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