Band 112, Heft 12

To further improve the uranyl adsorption capacity and the selectivity adsorption ability of marine fungus ZZF51 from Zhanjiang sea area in China, its two new modification biosorbents (ZTBA/ZTDA) linked by the open-chain polyether terminal with two/one amidoxime unit(s) on mycelium were designed according to the synthesis process of etherification, sulfonylation, substitution, and amidoximation. By the reasonable characterization of Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TG), and scanning electron microscopy (SEM), it was confirmed that the above target materials were successfully prepared. The relevant experiments showed that both of ZTBA and ZTDA had not only the excellent uranium (VI) adsorption performance with the maximum adsorption capacity of 525.7 mg g −1 and 465.7 mg g −1 , respectively, but also the better uranyl adsorption selectivity when in the simulated wastewater containing the various ions of UO 2 2+ , Th 4+ , Ba 2+ , Pb 2+ , Fe 3+ , Cu 2+ , and Ca 2+ . In addition, the selectivity analysis explored the longer polyether in the middle bridge and the more number of terminal amidoxime unit could synergistically improve their uranyl adsorption capacity and selectivity performance. Surely, the adsorption isotherm/kinetics models, the Gibbs free energy analysis, and the favourable reusability of the target materials were also discussed in this study in detail.

Theoretical evaluation of experimental extraction data of U (VI) from nitric acid solutions by tri- n -butyl phosphate (TBP) loaded on macro reticular polymer SM-7 was verified using Thomas and Yan models. These data are represented by breakthrough relations at different conditions; flow rate, concentrations and interfering ions. Comparing correlation coefficients ( R 2 ) of both models, it was found that R 2 equal 0.96 for Thomas model comparing to 0.88 for Yan one, indicating that Thomas model is convenient for evaluation of that extraction process. The calculated, theoretically, value of ( q Th ) was found to be almost equal to ( q exp ) the practical one.

99 Tc has a long half-life, high fission yield, and good environmental mobility, posing a significant threat to the environment and human health. Therefore, removing technetium from radioactive wastewater is a very important and urgent task. For laboratory safety reasons, ReO 4 − is often used as a non-isotopic substitute for 99 TcO 4 − . From this point of view, the study of the separation behavior of Re in the aqueous phase can provide a reference value for the removal of 99 Tc. Here, a new type of extraction chromatography resin was prepared by impregnating the functionalized ionic liquid into the macroporous resin, whose imidazolium cations modified by amide functional groups which can effectively capture ReO 4 − /TcO 4 − from simulated radioactive wastewater. The results show the resin has good adsorption performance and fast adsorption kinetics (the adsorption equilibrium is about 20 min). The adsorption mechanism was investigated using Fourier transform infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS). It shows that the adsorption process is an anion exchange between Cl − in the resin and ReO 4 − in the solution.

From extraction experiments and γ -activity measurements, the exchange extraction constants corresponding to the general equilibriums Sr 2+ (aq) + 2 picrate (aq) + L (nb) ⇔ SrL 2+ (nb) + 2 picrate (nb) and M 2+ (aq) + SrL 2+ (nb) ⇔ ML 2+ (nb) + Sr 2+ (aq) taking place in the two–phase water–nitrobenzene system (M 2+  = Ca 2+ , Ba 2+ , Pb 2+ , Cu 2+ , Zn 2+ , Cd 2+ , Mn 2+ , Co 2+ , Ni 2+ , UO 2 2 + ${\text{UO}}_{2}^{2+}$ ; L = substituted calix[5]arenes; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the ML 2+ complexes in nitrobenzene saturated with water were calculated. Very high stability constants of pentaethyl p-tert-butylcalix[5]arene pentaacetate ligand with Ba 2+ cation has been found.

Pancreatic cancer remains difficult to diagnose using currently available imaging probes. Thus, this study aimed to develop a novel imaging agent for the diagnosis of pancreatic cancer using positron emission tomography (PET). Specifically, this study explores gelatin-based nanoparticles fabricated via radiation-induced crosslinking, as gelatin is known for its ability to produce biocompatible materials. Aqueous gelatin solutions were irradiated with γ-rays to produce nanoparticles with average diameters of 5–20 nm via a radiation crosslinking technique. The gelatin nanoparticles were labeled with 64 Cu, exhibiting negative surface potentials. Furthermore, the nanoparticles were evaluated in vivo by injecting them into pancreatic tumor-bearing mice. Notably, the nanoparticles accumulated in the tumors. Hence, 64 Cu-labeled gelatin nanoparticles show promise as a platform for next-generation PET imaging agents for pancreatic cancer.

No-carrier-added (NCA) 161  Tb, which has advisable nuclear properties to be applied for cancer radiotherapy was produced at the Egyptian Second Research Reactor (ETRR-2) by neutron irradiation of natural gadolinium target via indirect nuclear reaction. The radiochemical separation of 161  Tb from irradiated gadolinium target was investigated based on solvent extraction technique using Cyanex 302. Several separation parameters were checked and optimized. According to the obtained results, the separation process of the investigated radioisotopes proceeds in two steps. The first step is an extraction of all of them into the organic phase in which the extraction % (98 %) was optimized at pH 4, 0.15 M of Cyanex 302 and 2.5 h extraction time. Moreover, the slope analysis method confirmed the participation of 2 mol of the organic extractant for the separation of 161  Tb from irradiated gadolinium. The second step is the separation of the 161  Tb isotope that was purified by the stripping of 159 Gd with a citrate solution at pH 9, which is considered as a highly efficient and promising method for separation and purification of the two radioisotopes.

The aim of this research is to assess the effectiveness of gamma irradiation in developing genetic variability in dragon fruit by influencing biochemical attributes. Seeds of dragon fruit were exposed to 100, 200, 300, 400 and 500 Gy γ-radiation using Co-60 source. Highest germinability, mean germination time, mean daily germination, vigour index and growth rate were observed in untreated seeds, however these traits were relatively less affected at lower irradiation level (up to 200 Gy). An irradiation level of ≥ 400 Gy severely affected germination traits and seedling growth and consequently 441 Gy irradiation level was considered as the lethal dose (LD 50 ) for dragon fruit. Photosynthetic pigments, protein content and nutrient content were highest in untreated seedlings and moderately high up to 200 Gy. Findings demonstrated that the concentration of biochemical markers for abiotic stress tolerance viz. proline, phenol, flavonoid and antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase), were significantly high at 200 Gy irradiation level. Hence an irradiation dose of 200 Gy may be considered as an optimal for induced mutagenesis for abiotic stress tolerance in dragon fruit with the least possible unintended damage to seedling growth traits. The findings provide valuable insights into the efficient utilization of γ-irradiation in expediting the development of abiotic stress-tolerant mutant lines of dragon fruit.

Nanocrystalline calcium titanate (CaTiO 3 ) doped with cerium ions (0.02 mol%) was synthesized via hydrothermal method and its luminescent properties were studied for gamma dosimetry. For the synthesized samples, the best luminescent response was achieved after annealing at 700 °C for 8 h. The synthesis was confirmed via XRD technique yielding the cyrstallite size of 22 nm for the most intense peak (121). The surface morphology was studied via scanning electron microscopy (SEM) yielding the grain size of 12 µm. The strong IR absorptions appeared at 700 cm−1 and 712 cm −1 attributed to bending mode of vibrations changing angle between Ti–O–Ti for CaTiO 3 and CaTiO 3 :Ce respectively, as confirmed via Fourier-Transform Infrared (FTIR) Spectroscopy. Thermoluminescent (TL) response of undoped and doped samples was studied by Mikrolab RA94 TLD Reader-Analyzer having heating rate 10 °C/s, for absorbed doses 0–20 mGy from 137 Cs γ-source having a dose rate 100 mSv/h. The found values at 662 keV for the photon-sensing parameters, i.e., mass attenuation coefficients ( μ / ρ ), mass-energy attenuation coefficient ( μ en / ρ ), effective atomic number for photon interaction ( Z eff,PI ) and effective atomic number for total photon energy absorption ( Z eff,PEA ) were 0.07030882 cm 2 /g, 0.0280245 cm 2 /g, 13.9 and 13.4 respectively. Thus, synthesized nanophosphor has shown excellent thermoluminescent dosimetric response for gamma radiation sensing in the selected dose range.

Melt-quenching was used to create high density glasses with a chemical composition of ( 15-x ) Na 2 O–45B 2 O 3 –20Bi 2 O 3 –20SiO 2 – x La 2 O 3 , where, x  = (0 ≤  x  ≥ 15) mol%. Through the use of (XRD) analysis, the amorphous status of these glasses was ascertained. We examined on the synthetic glasses physical attributes as well as their ability to shield against gamma radiation. The density increased from 4.913 g/cm 3 for BBSNLa0 glass to 6.497 g/cm 3 for BBSNLa15 glass. The study employed the Phy-X/PSD code to explore the radiation shielding properties of these glasses. As the mol% of La 2 O 3 increases, the MFP decreases. This indicates that glass samples with a higher concentration of La 2 O 3 have a greater ability to attenuate or absorb photons, resulting in a shorter average distance traveled before interaction. The BBSNLa-15 glass sample is the best choice for applications in radiation protection.

In this study, we have reported on the effect of the rare earth oxides on the radiation protection performance of the tellurite glasses. In order to determine the effect of rare earth oxides on the radiation shielding properties of tungsten oxide (WO 3 ) modified tellurite glasses, three rare earth element oxides (Nd 2 O 3 , Yb 2 O 3 , and Er 2 O 3 ) have been selected. The glass systems have been synthesized using the traditional melt quenching method and were doped with the different amount (1 %, 3 %, 5 %) of the oxides of rare earth elements (Nd 2 O 3 , Yb 2 O 3 , Er 2 O 3 ). The linear attenuation coefficient, mass attenuation coefficient, half value layer, and effective atomic number of the synthesized samples were experimentally measured for 662, 1,173 and 1,332 keV gamma-ray energies which were emitted from 137 Cs and 60 Co radioactive sources. Measurements were conducted in narrow beam transmission geometry using a NaI(Tl) scintillation detector. In addition, all these parameters were calculated theoretically using the WinXCOM program in the energy region of 0.015–15 MeV. The addition of different types and amounts of rare earth oxides to the tellurite glass system was found to significantly enhance the radiation protection performance of the glasses. In particular, it was found that the radiation shielding characteristics of the glasses improved with increasing amount of rare earth doping, the TWYb5 glass system had the best radiation shielding properties, and there was a trend among the doped rare earth oxides in the form of Yb > Er > Nd according to their radiation shielding performance.