Spatially resolved X-ray micro/nano-spectroscopy and imaging on the model organism Daphnia magna using laboratory and synchrotron sources

This work demonstrates and further develops spatially resolved laboratory and synchrotron X-ray spectroscopic and imaging experiments to answer specific ecotoxicological questions on the model organism Daphnia magna. The first phase of this work consisted of developing appropriate sample preparation procedures for this organism in order to be able to perform X-ray analyses on Daphnia magna subjected to ecotoxicological experiments. In the second phase, X-ray set-ups at different laboratories and synchrotron facilities were optimized and characterized in order to be able to perform the X-ray spectral imaging experiments of interest on Daphnia magna. Finally, various data reduction strategies were employed to process the vast amount of spectral data for evaluation and interpretation

Confocal micro-XRF/XANES analysis on insects trapped in amber

C

3D elemental imaging of the crustacean Ceriodaphnia by means of SR confocal micro-XRF

Daphnia is a freshwater crustacean (0.2-5 mm height) used for investigating the toxic effects of toxins (e.g. metals) on an ecosystem. Synchrotron radiation based micro X-ray fluorescence (SR micro-XRF) allows the investigation of the trace level metal distribution within these organisms in an essentially non-destructive manner. Several two-dimensional (2D), computed tomography (CT) and confocal micro-XRF experiments under conventional and cryogenic environments have been performed on Daphnia magna previously. However, due to its larger size (3 mm height) full three-dimensional (3D) imaging of the metal distributions is not practically feasible. In this contribution, we therefore report on the full 3D elemental imaging on Ceriodaphnia which is a smaller variant (1 mm height) by means of 3D confocal micro-XRF

SR 2D micro-XRF imaging on entire rat thin sections in view of a pharmacokinetic study of a new bromine containing drug agains tuberculosis

Tuberculosis (TB) is a common and often deadly infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis in humans. Because of population growth, the absolute number of new cases is still increasing. Multi-drug-resistant tuberculosis (MDR-TB) is defined as resistance to the two most effective first-line TB drugs and is a public health issue in many developing countries, as treatment is longer and requires more expensive drugs. Recently, a new experimental diarylquinoline anti-tuberculosis drug was discovered at Janssen Pharmaceutica, referred to as TMC207 and shown in Fig. 1. Before TMC207 can be made commercially available, one of the necessary investigations is a thorough pharmacokinetic study to investigate its absorption, distribution, metabolism and excretion (ADME)

Nanoscale chemical imaging of phagocytosis : a battle for metals between host and microbe

C