The concentration of carbon nanopipes (CNPs) can be detected and quantitatively measured in various matrices, including biological ones, using the methodology of formation of a gamma-emitting ...radioactive isotope marker in a CNP. The methodology has been tested in a 10-day experiment on the sprouting of wheat seeds on an artificial substrate damped by a water suspension of radioactively marked Taunit-M multiwall CNPs (MCNP) (Russia). Changes in the activities of samples of developing plant organs—root system, coleoptile and root base, and stem with leaves—makes it possible to define the quantitative concentration of MCNPs passing from a substrate with a known concentration of the given nanomaterial into a plant. The results show promising outlooks for applying this methodology for quantitative measurements of CNP mass/concentration in various media and biological objects.
A radiotracer technique is developed using titanium dioxide nanoparticles labeled by fast protons with the acquisition of a
48
V radioactive isotope, and the biokinetics of these brookite ...nanoparticles in the organisms of laboratory rats within the one-time intragastrical injection are studied. The main result of this work is the detection of titanium dioxide in the colon even within 5 days after injecting the slurry in an amount of 0.4% from the total exposition dose, which evidences the accumulation of titanium dioxide nanoparticles in the organ. This means that macro- and nano-fractions of titanium dioxide particles can be potentially dangerous for the colon, exerting a toxic and carcinogenic influence on its epithelial cells. Moreover, some traces of titanium dioxide nanoparticles are found to penetrate into the blood and liver. However, 98% of titanium dioxide is eliminated from the organism with feces within 5 days after injection. Neither kidneys nor brain exhibit the presence of titanium dioxide residues. This effect is due to the agglomeration of titanium dioxide nanoparticles, which is already significant and prompt in the solution for injection. At the same time, despite the ability of agglomerates to dissociate in the acidic medium of the stomach, only a few amounts of titanium dioxide pass into a nanometric form, which then penetrates through the colon into blood.
Irradiation of 186W targets by 3He particles was carried out. For the first time the cross sections for the reactions of production of 183, 184, 186, 188Re, 183, 185Os, 187W were measured by the ...stack foil technique in the 3He energy range of 15–45 MeV. The results were compared to the data from the TENDL-2019 library. Using the experimental excitation functions, the thick target yields of medically relevant rhenium radioisotopes were calculated.
•The production cross sections of radioisotopes from 3He-particle induced reactions on 186W target are measured.•The results are compared with data from the TENDL-2019 library.•The suitability of the method for the production of medical radionuclides 186Re and 188Re is evaluated.
Four terbium isotopes
Tb emitting various types of radiation can be used for both diagnostics and therapy.
Tb emits positrons and is ideal for PET.
Tb is considered a promising Auger emitter and a ...diagnostic pair for other terbium therapeutic isotopes. Several methods for the production of
Tb using charged particle accelerators have been proposed, but they all have significant limitations. The restricted availability of this isotope hinders its medical applications. We have proposed a new method for production of
Tb, irradiating enriched
Gd by alpha particles. The possibility of simultaneous production of two isotopes of terbium,
Tb, was also studied for more efficient cyclotron beam use.
Irradiation of
Gd enriched targets and
Gd /
Eu tandem target with alpha-particles with an energy of 54 MeV was carried out at the U-150 cyclotron at the NRC "Kurchatov Institute". The cross sections of nuclear reactions on
Gd were measured by the stack foil technique, detecting the gamma-radiation of the activation products. The separation of rare earth elements was performed by extraction chromatography with the LN Resin.
Tb was produced via
Dy decay.
The cross sections for the
Tb and
Dy production were measured by the irradiation of a gadolinium target enriched with the
Gd isotope with alpha-particles in an energy range of 54 → 33 MeV. The yield of
Dy on a thick target at 54 MeV was 130 MBq/μAh, which makes it possible to obtain 1 GBq of
Tb in 11 hour-irradiation with 20 μA beam current. The possibility of simultaneous production of
Tb by irradiation of
Gd and
Eu tandem target with medium-energy alpha-particles is implemented. Optimal irradiation energy ranges of alpha -particles as 54 → 42 MeV for
Tb and 42 → 34 MeV for
Tb were suggested. Product activity and radionuclidic purity were calculated.
Irradiation of
W targets by
He particles was carried out. For the first time the cross sections for the reactions of production of
Re,
Os,
W were measured by the stack foil technique in the
He energy ...range of 15-45 MeV. The results were compared to the data from the TENDL-2019 library. Using the experimental excitation functions, the thick target yields of medically relevant rhenium radioisotopes were calculated.
