Submitted on: 20 October 2013.
Revised on: 05 February 2014.
Accepted on: 15 March 2014.
___________________Deutsches Arzteblatt International
http://reply.papertrans.cn/1/74/7328/7328-32.png
http://reply.papertrans.cn/1/74/7328/7328-33.png
http://reply.papertrans.cn/1/74/7328/7328-34.png
Submitted on: 30 January 2013.
Revised on: 14 March 2013.
Accepted on: 06 May 2013.
___________________Deutsches Arzteblatt International
Submitted on: 25 September 2017.
Revised on: 08 December 2017.
Accepted on: 01 February 2018.
___________________Deutsches Arzteblatt International