Okulov, I. V.
Soldatov, I. V.
Sarmanova, M. F.
Kaban, I.
Gemming, T.
Edström, K.
Eckert, J.
Article History
Received: 26 February 2015
Accepted: 25 June 2015
First Online: 29 July 2015
Competing interests
: The authors declare no competing financial interests.