http://reply.papertrans.cn/1/18/1760/1760-31.png
http://reply.papertrans.cn/1/18/1760/1760-32.png
http://reply.papertrans.cn/1/18/1760/1760-33.png
Submitted on: 15 October 2008.
Revised on: 29 January 2009.
Accepted on: 20 February 2009.
___________________Annals of Clinical and Analytical Medicine
http://reply.papertrans.cn/1/18/1760/1760-35.png
http://reply.papertrans.cn/1/18/1760/1760-36.png