Fig. 6
a Hierarchical Cluster Analysis of IR images representative of LASER and MACHINED samples (light blue color indicates the clusters richer in collagen). Mean absorbance IR spectra extracted from the clusters richer in collagen of LASER (light bleu lines) and MACHINED (blue lines) samples: b 1760–1490 cm–1 and c 1360–900 cm–1 spectral ranges. Spectra are offset along the y axis for a better comprehension. The position of the most significant bands is indicated over the spectra (wavenumbers, cm−1)