http://reply.papertrans.cn/1/13/1265/1265-31.png
Submitted on: 14 April 2011.
Revised on: 31 July 2011.
Accepted on: 03 September 2011.
___________________AMERICAN FAMILY PHYSICIAN---AMER ACAD FAMILY PHYSICIANS
http://reply.papertrans.cn/1/13/1265/1265-33.png
http://reply.papertrans.cn/1/13/1265/1265-34.png
http://reply.papertrans.cn/1/13/1265/1265-35.png
http://reply.papertrans.cn/1/13/1265/1265-36.png