2.6. Statistical analysis
The data were analyzed by student t-test using statistical
package for social sciences statistical analysis software (version
11.5; SPSS Inc., Chicago, Illinois, USA). All values were expressed as
mean
standard deviation. Differences were regarded as significant
or highly significant if probability value P < 0.05 or P < 0.001
respectively (Dawson-Saunders and Trapp, 2001).