Submitted on: 18 July 2006.
Revised on: 13 November 2006.
Accepted on: 29 December 2006.
___________________Deutsches Arzteblatt International
Submitted on: 12 February 2000.
Revised on: 05 June 2000.
Accepted on: 03 August 2000.
___________________Deutsches Arzteblatt International
Submitted on: 28 July 2013.
Revised on: 22 November 2013.
Accepted on: 06 January 2014.
___________________Deutsches Arzteblatt International
http://reply.papertrans.cn/1/74/7328/7328-24.png
Submitted on: 21 August 2010.
Revised on: 17 September 2010.
Accepted on: 05 October 2010.
___________________Deutsches Arzteblatt International
http://reply.papertrans.cn/1/74/7328/7328-26.png
http://reply.papertrans.cn/1/74/7328/7328-27.png
Submitted on: 19 January 2004.
Revised on: 08 April 2004.
Accepted on: 08 May 2004.
___________________Deutsches Arzteblatt International
http://reply.papertrans.cn/1/74/7328/7328-29.png
Submitted on: 22 January 2017.
Revised on: 23 February 2017.
Accepted on: 01 April 2017.
___________________Deutsches Arzteblatt International