Fig. 1From: Differential activation of RAW 264.7 macrophages by size-segregated crystalline silicaComparison of SEM images of the four sizes of crystalline silica particles used for this study, (a) Ultrafine (UF), (b) Submicron (S), (c) Respirable (R), and (d) Coarse (C). Images are all at the same magnification (5,000x)Back to article page