Dynamic In Vivo Chest X-ray Dark-Field Imaging in Mice.

X-ray grating interferometry is a powerful emerging tool in biomedical imaging, providing access to three complementary image modalities. In addition to the conventional attenuation modality, interferometry provides a phase modality, which visualizes soft tissue structures, and a dark-field modality, which relates to the number and size of sub-resolution scattering objects. A particularly strong dark-field signal originates from the alveoli or air sacs in the lung. Dark-field lung radiographs in animal models have already shown increased sensitivity in diagnosing lung diseases, such as lung cancer or emphysema, compared to conventional X-ray chest radiography. However, to date, X-ray dark-field lung imaging has either averaged information over several breaths or has been captured during a breath hold. In this paper, we demonstrate the first time-resolved dark-field imaging of a breath cycle in a mechanically ventilated mouse, in vivo, which was obtained using a grating interferometer. We achieved a time resolution of 0.1 s, visualizing the changes in the dark-field, phase, and attenuation images during inhalation and exhalation. These measurements show that the dark-field signal depends on the air volume and, hence, the alveolar dimensions of the lung. Conducting this type of scan with animal disease models would help to locate the optimum breath point for single-image diagnostic dark-field imaging and could indicate if the changes in the dark-field signal during breath provide a diagnostically useful complementary measure.

Ptychographic X-ray nanotomography quantifies mineral distributions in human dentine.

Bones are bio-composites with biologically tunable mechanical properties, where a polymer matrix of nanofibrillar collagen is reinforced by apatite mineral crystals. Some bones, such as antler, form and change rapidly, while other bone tissues, such as human tooth dentine, develop slowly and maintain constant composition and architecture for entire lifetimes. When studying apatite mineral microarchitecture, mineral distributions or mineralization activity of bone-forming cells, representative samples of tissue are best studied at submicrometre resolution while minimizing sample-preparation damage. Here, we demonstrate the power of ptychographic X-ray tomography to map variations in the mineral content distribution in three dimensions and at the nanometre scale. Using this non-destructive method, we observe nanostructures surrounding hollow tracts that exist in human dentine forming dentinal tubules. We reveal unprecedented quantitative details of the ultrastructure clearly revealing the spatially varying mineralization density. Such information is essential for understanding a variety of natural and therapeutic effects for example in bone tissue healing and ageing.

PCDD/F- and PAH-emission from house heating systems.

Combustion experiments were carried out in different house heating systems using various fuels. The emission samples and the chimney soot samples were analyzed for polychlorinated dibenzo-p-dioxins/furans (PCDD/F) and polycyclic-aromatic-hydrocarbons (PAH). The PCDD/F-concentrations in fluegases using untreated wood were in the range of 2-25 pg I-TE/m3. The combustion of paper, cartons, painted wood and wood with 2-5% PVC gave PCDD/F-concentrations from 38 to 952 pg I-TE/m3 and 380 to 2,240 ng I-TE/kg (chimney soot). The PAH-concentrations in flue gas were about 30 times higher using an old technology in relation to a new one.

Polyhalogenated dibenzo-p-dioxins and dibenzofurans in the exhaust air during textile processings.

5 textile finishing processes were investigated for polychlorinated dibenzo-p-dioxins/furans (PCDD/F), polybrominated dibenzo-p-dioxins/furans (PBDD/F) and mixed polychlorinated-brominated dibenzo-p-dioxins/furans (PBCDD/F). For the purpose of these investigations the complete balance--dioxins input from the raw textiles, output over the finished textiles and output through the air path--was done. In the exhaust air only small PXDD/F concentration were detected. The textiles contain before and after the process nearly the same PCDD/F-concentrations. The concentrations of PBCDD/F arises after the process. Only the chimney depositions contain higher PCDD/F-concentrations up to 1,806.1 ng I-TE/kg, PBDD/F-concentrations up to 1,572.6 ng/kg and PBCDD/F-concentrations up to 40,801.4 ng/kg.