**4.2.1.4 Statistical analysis**

The software of SPSS 13.0 was used for statistical analysis. The deviation between the three groups was calculated by analysis of one-factor variance (ANOVA), and the deviation between samples in one group was calculated by Student-Newman-Keuls (q-test). All the data are shown by mean values and standard deviations (ms), p<0.05 is considered to have statistical difference.
