() An SEM image illustrating the lacy openwork character typical of the BDS aggregates; individual, solid, spherical particles, 50–70 nm in diameter, are the fundamental structural units of the aggregates

Copyright information:Taken from "Combustion-Derived Ultrafine Particles Transport Organic Toxicants to Target Respiratory Cells"Environmental Health Perspectives 2005;113(8):956-963.Published online 6 May 2005PMCID:PMC1280333.This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI. () A TEM image of BDS showing individual spheres, 30–50 nm in diameter, arranged in branching clusters. The difference in diameter of the spheres in the SEM versus TEM images results from the 10–20 nm gold/palladium conductive coating that was applied to the SEM samples. () A TEM image of a portion of the surface of a BEAS-2B cell with individual spherical particles, 30–50 nm in diameter, and small aggregates (arrows) immediately adjacent to the cell membrane. Cells were photographed after 42 hr exposure.