Reactive oxygen species generation in aqueous solutions containing GdVO:Eu nanoparticles and their complexes with methylene blue.

It this letter, we report the study of free radicals and reactive oxygen species (ROS) generation in water solutions containing gadolinium orthovanadate GdVO:Eu nanoparticles (VNPs) and their complexes with methylene blue (MB) photosensitizer. The catalytic activity was studied under UV-Vis and X-ray irradiation by three methods (conjugated dienes test, OH· radical, and singlet oxygen detection). It has been shown that the VNPs-MB complexes reveal high efficiency of ROS generation under UV-Vis irradiation associated with both high efficiency of OH· radicals generation by VNPs and singlet oxygen generation by MB due to nonradiative excitation energy transfer from VNPs to MB molecules.

[A study of a two-energy bar of detectors for x-ray osteodensitometry].

Described are the results of mathematic modeling for different types of detectors (with different scintillators for high- and low-energy spectrum ranges) as well as the results of experimental research. It was also analyzed of how a manufacturing technology of ZnSe(Te) and CsI(Tl)-based scintillators affects the detector-bar resolution ability. Finally, the influence of signals in canals of detectors on the signals in neighboring canals was investigated.