Observation of Atmospheric Samples by 3D-SGXM Figure 6. Final 3D model and its projections. (A) Each projection (1 to 7) from the final 3D volume corresponds to the views from the X-ray PDs (240.2u to 45u). These images are very similar to the original X-ray images (Figure 2B). (B) Surface-rendered image of a bacterium is obtained by using 2s that is greater than the mean value of the final 3D model. (C) Top view of 3D image of a bacterium, obtained by 90u rotation of 3D view shown in (B). (D) Cross section parallel to the vertical axis through the 3D volume with colour map to indicate density. The high-density region is coloured red and is visible at the right bottom end of the bacterium. (E) Cross section perpendicular to the vertical axis. The high-density region is located at the right side of the bacterium. doi:10.1371/journal.pone.0021516.g006 Correction of X-ray PD images and image processing Each linear XPD element detects a tilt image according to its position. With respect to EB, the angles hx between the EB- irradiated spot on the sample and the PD elements range from 240.2u to 45.0u (Figure S2C). The detection length of each XPD is shortening from the distance of EB scanning on Si3N4 film by its set angle of hx, these reduction rates are calculated by cos(hx) (Figure S2B). Therefore, horizontal ratio at each constructed X- ray image is expanded by the EB scan signal at its XPD setting position, because the observed length by scan signal is based on a PLoS ONE | www.plosone.org 7 June 2011 | Volume 6 | Issue 6 | e21516