<p>Samples were collected 0.25, 0.5, 1, 2, 4, 8 and 24 hours after sham or actual irradiation. Transcriptional profiling was performed using Agilent gene expression microarrays and comprises three major steps: the identification of differentially expressed genes from time-course expression data by employing a natural cubic spline regression model; the use of regularized dynamic partial correlation method to infer gene associations networks from differentially expressed genes and the topological identification and functional characterization of the key nodes in the reconstructed networks.</p
