Fig. 3From: Endothelial responses of the alveolar barrier in vitro in a dose-controlled exposure to diesel exhaust particulate matterScanning electron microscopy micrographs of empty Transwellâ„¢ inserts after exposure to DEPM aerosol using the PALAS steel-brush-generator. Transwellâ„¢ inserts were pre-wetted and then exposed to: a: 40Â ng/cm2; b: 80Â ng/cm2; c: 240Â ng/cm2 Back to article page