Separation of americium from highly active raffinates by an innovative variant of the AmSel process based on the ionic liquid Aliquat-336 nitrate.

A new variant of the AmSel (Americium Selective Separation) system for the separation of Am(iii) from a PUREX raffinate was tested in which the aliphatic diluent was replaced by the ionic liquid Aliquat-336 nitrate. For this ionic liquid variant, the kinetics, and the influence of both the HNO concentration and the ligand concentration on the stripping were evaluated. In addition, both the original AmSel system, and the ionic liquid variant were demonstrated on a simulated highly active raffinate.

Gamma radiation effects on AG MP-50 cation exchange resin and sulfonated activated carbon for bismuth-213 separation.

Medical Ac/Bi radionuclide generators are designed to provide a local supply of the short-lived Bi for cancer treatment. However, radiation-induced damage to the sorbents commonly used in such radionuclide generators remains a major concern. In this study, the effects of gamma radiation on AG MP-50 cation exchange resin and sulfonated activated carbon (SAC) were studied by analyzing the changes in the morphological characteristics, functional groups, and the La/Bi sorption performance, with La being a suitable non-radioactive substitute for Ac.

Speciation and Ammonia-Induced Precipitation of Neptunium and Uranium Ions.

The pH evolution and corresponding changes in the UV-Vis-NIR absorption spectra of oxygenated neptunium (NpO and NpO) and uranyl ions (UO) in nitric acid are investigated during titration with an aqueous NH solution. The speciation and precipitation regimes between acidic (pH 1.5) and alkaline (pH 10) conditions at room temperature are discussed to assess the suitability of Np(V) or Np(VI) in sol-gel conversion processes for fuel target fabrication.

Application of multi-edge HERFD-XAS to assess the uranium valence electronic structure in potassium uranate (KUO).

The uranium valence electronic structure in the prototypical undistorted perovskite KUO is reported on the basis of a comprehensive experimental study using multi-edge HERFD-XAS and relativistic quantum chemistry calculations based on density functional theory. Very good agreement is obtained between theory and experiments, including the confirmation of previously reported Laporte forbidden f-f transitions and X-ray photoelectron spectroscopic measurements. Many spectral features are clearly identified in the probed U-f, U-p and U-d states and the contribution of the O-p states in those features could be assessed.

Radiolabeling of Human Serum Albumin With Terbium-161 Using Mild Conditions and Evaluation of Stability.

Targeted radionuclide therapy (TRNT) is a promising approach for cancer therapy. Terbium has four medically interesting isotopes (Tb, Tb, Tb and Tb) which span the entire radiopharmaceutical space (TRNT, PET and SPECT imaging). Since the same element is used, accessing the various diagnostic or therapeutic properties without changing radiochemical procedures and pharmacokinetic properties is advantageous.

Production of Sm-153 With Very High Specific Activity for Targeted Radionuclide Therapy.

Samarium-153 (Sm) is a highly interesting radionuclide within the field of targeted radionuclide therapy because of its favorable decay characteristics. Sm has a half-life of 1.93 d and decays into a stable daughter nuclide (Eu) whereupon β particles [E = 705 keV (30%), 635 keV (50%)] are emitted which are suitable for therapy.

Charge Localization and Magnetic Correlations in the Refined Structure of UO.

Atomic arrangements in the mixed-valence oxide UO are refined from high-resolution neutron scattering data. The crystallographic model describes a long-range structural order in a UO primitive cell (space group 4/) containing distorted cuboctahedral oxygen clusters. By combining experimental data and electronic structure calculations accounting for spin-orbit interactions, we provide robust evidence of an interplay between charge localization and the magnetic moments carried by the uranium atoms.

Bismuth-213 for Targeted Radionuclide Therapy: From Atom to Bedside.

In contrast to external high energy photon or proton therapy, targeted radionuclide therapy (TRNT) is a systemic cancer treatment allowing targeted irradiation of a primary tumor and all its metastases, resulting in less collateral damage to normal tissues. The α-emitting radionuclide bismuth-213 (Bi) has interesting properties and can be considered as a magic bullet for TRNT. The benefits and drawbacks of targeted alpha therapy with Bi are discussed in this review, covering the entire chain from radionuclide production to bedside.

Selective extraction of trivalent actinides using CyMeBTPhen in the ionic liquid Aliquat-336 nitrate.

The extraction of Am(iii), Cm(iii) and Eu(iii) by 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMeBTPhen) from nitric acid solution was studied using the ionic liquid Aliquat-336 nitrate ([A336][NO]) as diluent. Results show a high selectivity of the solvent for Am(iii) and Cm(iii) over Eu(iii), but rather slow extraction kinetics. The kinetics of CyMeBTPhen were largely improved by the addition of 0.

Therapeutic Efficacy of Bi-labeled sdAbs in a Preclinical Model of Ovarian Cancer.

Targeted alpha-particle therapy (TAT) might be a relevant therapeutic strategy to circumvent resistance to conventional therapies in the case of HER2-positive metastatic cancer. Single-domain antibody fragments (sdAb) are promising vehicles for TAT because of their excellent properties, high target affinity, and fast clearance kinetics. This study combines the cytotoxic α-particle emitter bismuth-213 (Bi) and HER2-targeting sdAbs.

Local Structure in U(IV) and U(V) Environments: The Case of UO.

A comprehensive analysis of X-ray absorption data obtained at the U -edge for a systematic series of single-valence (UO, KUO, UO) and mixed-valence uranium compounds (UO, UO, UO) is reported. High-energy resolution fluorescence detection (HERFD) X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) methods were applied to evaluate U(IV) and U(V) environments, and in particular, to investigate the UO local structure. We find that the valence state distribution in mixed-valence uranium compounds cannot be confidently quantified from a principal component analysis of the U -edge XANES data.

Stability of europium(ii) in aqueous nitrate solutions.

In the lanthanide series, Eu3+ is most easily reduced to its divalent state. Reduction of Eu3+ has been studied extensively in aqueous media that are insensitive to reducing conditions. Recently, it has been reported that reduction of Eu3+ is also feasible in aqueous nitrate solutions and that Eu2+ remained sufficiently stable in these media to conduct separation experiments.

Gold nanoparticles affect the antioxidant status in selected normal human cells.

This study evaluates the cytotoxicity of AuNPs coated with polyallylamine (AuNPs-PAA) and conjugated or not to the epidermal growth factor receptor (EGFR)-targeting antibody Cetuximab (AuNPs-PAA-Ctxb) in normal human kidney (HK-2), liver (THLE-2) and microvascular endothelial (TIME) cells, and compares it with two cancer cell lines that are EGFR-overexpressing (A431) or EGFR-negative (MDA-MB-453). Conjugation of Cetuximab to AuNPs-PAA increased the AuNPs-PAA-Ctxb interactions with cells, but reduced their cytotoxicity. TIME cells exhibited the strongest reduction in viability after exposure to AuNPs-PAA(±Ctxb), followed by THLE-2, MDA-MB-453, HK-2 and A431 cells.

Labeling of Anti-HER2 Nanobodies with Astatine-211: Optimization and the Effect of Different Coupling Reagents on Their in Vivo Behavior.

The use of nanobodies (Nbs) as vehicles in targeted alpha therapy (TAT) has gained great interest because of their excellent properties. They combine high in vivo affinity and specificity of binding with fast kinetics. This research investigates a novel targeted therapy that combines the α-particle emitter astatine-211 (At) and the anti-HER2 Nb 2Rs15d to selectively target HER2+ cancer cells.

ALPHABETA: a dedicated open-source tool for calculating TEM stage tilt angles.

This work describes the concepts, the mathematical framework and the implementation of the open source ALPHABETA software, a dedicated tool for calculating α and β tilt angles on any TEM double tilt stage. ALPHABETA provides an intuitive user interface to calibrate the orientation of the region of interest and to subsequently calculate the angle tilts to reach a zone axis, to perform a rotation around a given reflection, or to set up a 2-beam or weak beam condition. The orientation of the sample on the stage and the tilt range reachable domain can be visualised in a stereographic projection plot.

Low-Temperature Oxidation of Fine UO Powders: Thermochemistry and Kinetics.

The thermochemical behavior of low-temperature oxidation in fine UO powders has been investigated by simultaneous thermogravimetric analysis and differential scanning calorimetry. The evaluation of the thermochemical and kinetic data reveals a complex interplay between different mechanisms. The initial reaction concerns the rapid chemisorption of oxygen gas onto the surface of UO grains, having an activation energy of only 13.

Improving atomic displacement and replacement calculations with physically realistic damage models.

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations.

Evolution of the Uranium Chemical State in Mixed-Valence Oxides.

A fundamental question concerning the chemical state of uranium in the binary oxides UO, UO, UO, UO, and UO is addressed. By utilizing high energy resolution fluorescence detection X-ray absorption near edge spectroscopy (HERFD-XANES) at the uranium M edge, a novel technique in the tender X-ray region, we obtain the distribution of formal oxidation states in the mixed-valence oxides UO, UO, and UO. Moreover, we clearly identify a pivot from U(IV)-U(V) to U(V)-U(VI) charge compensation, corresponding with transition from a fluorite-type structure (UO) to a layered structure (UO).

Assessment of the UO Crystal Structure by X-ray and Electron Diffraction.

Polycrystalline UO powder was synthesized by oxidation of UO powder under controlled conditions using in situ thermal analysis, and by heat treatment in a tubular furnace. The O/U ratio of the UO phase was measured as 2.34 ± 0.

Low-Temperature Oxidation of Fine UO2 Powders: A Process of Nanosized Domain Development.

The nanostructure and phase evolution in low-temperature oxidized (40-250 °C), fine UO2 powders (<200 nm) have been investigated by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). The extent of oxidation was also measured via in situ thermogravimetric analysis. The oxidation of fine powders was found to proceed differently as compared to oxidation of coarse-grained UO2.