FdDES at FGF 0.5 L x min ( -1 ) ( 6.13 + / - 0.12 ) was significantly higher than FdDES at 1 and 2 L x min ( -1 ) ( 5.68 + / - 0.08 , 5.54 + / - 0.07 , respectively ) , but not significantly different between FGF 1 and 2 L x min ( -1 ) .