Carbon Nanomaterials for Sorption of 68Ga for Potential Using in Positron Emission Tomography.

In present work, carbon nanomaterials (CNMs) are investigated as potential carriers of 68Ga, which is widely used in positron emission tomography (PET) in nuclear medicine. Sorption behavior of 68Ga was studied onto CNMs of various structures and chemical compositions: nanodiamonds (ND), reduced graphite oxide (rGiO) and multi-walled carbon nanotubes (MWCNT), as well as their oxidized (ND-COOH) or reduced (rGiO-H, MWCNT-H) forms. The physicochemical properties of the nanoparticles were determined by high resolution transmission electron microscopy, x-ray photoelectron spectroscopy, dynamic light scattering and potentiometric titration. The content of 68Ga in the solutions during the study of sorption was determined by gamma-ray spectrometry. The highest degree of 68Ga sorption was observed on ND and ND-COOH samples, and the optimal sorption conditions were determined: an aqueous solution with a pH of 5-7, m/V ratio of 50 µg/mL and a room temperature (25 °C). The 68Ga@ND and 68Ga@ND-COOH conjugates were found to be stable in a model blood solution-phosphate-buffered saline with a pH of 7.3, containing 40 g/L of bovine serum albumin: 68Ga desorption from these samples in 90 minutes was no more than 20% at 25 °Ð¡ and up to 30% at 37 °Ð¡. Such a quantity of desorbed 68Ga does not harm the body and does not interfere with the PET imaging process. Thus, ND and ND-COOH are promising CNMs for using as carriers of 68Ga for PET diagnostics.

Redetermination of the crystal structure of NaTcO4 at 100 and 296†K based on single-crystal X-ray data.

The redetermination of the title compound, sodium pertechnate, from single-crystal CCD data recorded both at 296 and 100 K confirms previous studies based on X-ray powder diffraction film data [Schwochau (1962 ▸). Z. Naturforsch. Teil A, 17, 630; Keller & Kanellakopulos (1963 ▸). Radiochim. Acta, 1, 107-108] and neutron powder diffraction data using the Rietveld method [Weaver et al. (2017 ▸). Inorg. Chem.12, 677-681], but reveals a considerable improvement in precision. The standard uncertainties of the room-temperature structure determination are about seven times lower than those of the neutron diffraction structure determination and about 13 times lower at 100 K, due to the decrease in the amplitude of librations. The crystal expansion could be approximated linearly with a thermal volumic expansion coefficient of 1.19 (12) × 10-4 K-1. NaTcO4 adopts the scheelite (CaWO4) structure type in space group type I41/a with Na and Tc atoms (both with site symmetry -4) replacing Ca and W atoms, respectively.