2.6 Statistical analyses
IBM SPSS Statistics for Windows, version 22.0 (IBM Corp., Armonk, N.Y.,
USA) was used for data analysis. Continuous data were summarized as mean
± standard deviation (x ± s) and compared using t-tests (normally
distributed data) or non-parametric tests (non-normally distributed
data). Statistical significance was set as P < 0.05.