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Widely present in Japan's deep subterranean formations, pre-Neogene sedimentary rocks offer an option for high-level radioactive waste (HLW) deep geological disposal due to their favorable properties. However, their barrier properties necessitate further investigation. This research examines the characteristics of pre-Neogene sedimentary rocks, focusing on two rock types: the melange type with a distinct block-in-matrix structure and the sandstone-dominant coherent type. Their ability and mechanism to sorb Cs+ and Eu3+ are assessed, and the differences between the two types are compared. The influence of inorganic carbon in groundwater and the role of clay minerals, such as illite, in the sorption of these metal ions, are highlighted. This investigation lays the groundwork for future studies on migration behaviors of radionuclides, essential for ensuring the long-term safety of HLW geological disposal. [ABSTRACT FROM AUTHOR]

The barrier effect of calcium silicate hydrate (C – S – H), which is secondarily formed around a repository owing to the utilization of cementitious materials, was explored. Eu was employed as a chemical analog of Am (a key radionuclide in high-level radioactive wastes), and its interaction with C – S – H was analyzed via synthesis experiments. For the experiments, calcium oxide, fumed silica, and a Eu solution were mixed to interact Eu with C – S – H that had not undergone drying. Fluorescence Raman spectroscopies were performed to analyze the coexistence of Eu with C – S – H. The results indicated that Eu was mostly undissolved in the liquid phase and that it was incorporated into the C – S – H structure rather than precipitated as its hydroxide species even at the pH conditions for Eu hydrolysis. Additionally, the C – S – H formation at 50°C, as well as its incorporation of Eu, were accelerated compared to 25°C. The findings indicated the possibility of immobilizing Eu and Am by C – S – H formed in the underground environment even under groundwater conditions in which Eu and Am form mobile colloids via the hydrolysis. [ABSTRACT FROM AUTHOR]

No effective technique exists for removing adhesive remnants following bracket debonding. We propose that fluorescence imaging using europium ions (Eu3+) offers an effective solution for minimizing iatrogenic enamel damage. This study aimed to assess the impact of different mixing ratios of monomer mixtures on the photoluminescence and flexural properties of a newly developed fluorescent adhesive. Four monomer blends with varying urethane dimethacrylate (UDMA) to triethylene glycol dimethacrylate (TEGDMA) ratios were prepared and polymerized. The blends contained 0.1 wt% of tris(1,3-diphenyl-1,3-propanedionato)(1,10-phenanthroline) Eu(III), [Eu(DBM)3Phen], as the phosphor. Optical measurements and flexural tests were conducted for each resin specimen. The emission spectra exhibited narrow bands corresponding to the 4f-4f transitions of the Eu3+ ions. The photoluminescence properties remained unaffected by the mixing ratio, whereas the mechanical properties tended to improve with higher UDMA content. We conclude that the Eu(DBM)3Phen-containing resin shows promise as a fluorescent orthodontic adhesive that contributes to preserving enamel health. [ABSTRACT FROM AUTHOR]

This investigation aimed to establish the geographical traceability of Malaysian rice by assessing the elemental composition in paddy soil. Multi-element determination in combination with a chemometric approach was applied to evaluate the elemental concentrations of paddy soil from granaries cultivated with the same rice variety and to assess the relationship between elements in the soil and rice (SAR) system. A total of 29 elements (aluminum, arsenic, barium, bromine, calcium, chlorine, cobalt, chromium, cesium, europium, iron, gallium, hafnium, potassium, lanthanum, lutetium, magnesium, manganese, sodium, rubidium, antimony, scandium, samarium, thorium, titanium, uranium, vanadium, ytterbium and zinc) were successfully determined in paddy soil from Kedah, Selangor and Langkawi by neutron activation analysis. A significant difference (P < 0.05) between 18 elements in the soil samples was obtained. The chemometric approaches of principal component and linear discriminant analyses demonstrated clear discrimination and highly corrected classification (100%) of the soil samples. A high classification (98.1%) was also achieved by assessing 10 elements (aluminum, arsenic, bromine, chlorine, potassium, magnesium, manganese, sodium, rubidium and zinc), which similarly applied to rice geographical origin determination. Similar elements in SAR were also observed for differences in the pattern of correlation and bioaccumulation factor between the granaries. Furthermore, the generalized Procrustes analysis showed a 98% consensus between SAR and clear differences between the studied regions. The canonical correlation analysis demonstrated a significant correlation between the chemical profile of SAR (r 2 = 0.88, P < 0.001). Therefore, the current work model provides a reliable assessment to establish rice provenance. [ABSTRACT FROM AUTHOR]

In this work, NH4Cl flux-assisted solution combustion synthesis of Eu3+-doped CdSiO3 phosphor has been reported. The prepared phosphor has been characterised using XRD, SEM, FTIR, UV–Vis and PL techniques. The influence of NH4Cl flux on the structural, morphological and photoluminescence (PL) properties has been thoroughly investigated. The PL spectra of 5 mol% Eu3+-doped CdSiO3 nanophosphor monitored at Eu3+ emission wavelength of 613 nm, consists of four broad excitation peaks centred at 362 nm, 381 nm, 393 nm and 414 nm ascribed to Eu3+ ion transitions from its 7F0 ground state energy level to different excited energy states 5H3, 5L7, 5L6 and 5D3, respectively. CdSiO3:Eu3+ samples prepared by using 6 wt% flux showed appreciable improvement in emission intensity in the studied concentration limit. The observed improvement in the orange-red photoluminescence is due to effective substitution of Eu3+ ions in the CdSiO3 lattice. [ABSTRACT FROM AUTHOR]

• The europium vanadate nanoparticles decorated carbon nanofiber composites were synthesized through simple ultrasonic assisted hydrothermal method. • In different characterization using like XRD and SEM of EuVO 4 /f-CNF composite. • This modified electrode EuVO 4 /f-CNF was showed good sensing property like repeatability, reproducibility, stability and shower detection limit of 0.0006 μM. • Also, the modified electrode underscoring its real-world samples of grape and watermelon. Fungicides, like carbendazim, have effects on male fertility. There have been sufficient studies conducted on certain chemical compounds to indicate a selective action at the epididymis level. To prevent contamination of food products with fungicides, most of the governments have established rules for the use of fungicides. However, even though this type of fungicide is primarily used in agriculture. More probably, it's contaminated with fruits and vegetables. In particular, carbendazim is one of the major fungicides in the agricultural usage This research work developed a europium vanadate (EuVO 4) nanoparticle decorated carbon nanofiber (CNF) composites by hydrothermal-sonochemical approach. Based on this composite, Carbendazim sensing is developed through electrochemical oxidation based on EuVO 4 /f-CNF modified Glassy Carbon Electrode (GCE). By combining EuVO 4 and f-CNF with the GCE, carbendazim detection can be highly effective. GCEs are rigid, making them ideal for depositing EuVO 4 /f-CNF, while their expansive surface area makes it possible to immobilize a greater amount of EuVO 4 /f-CNF, which could increase the Carbendazim sensing ability of the resulting modified GCEs with EuVO4/f-CNF. : The carbendazim sensing was actualized by the electrocatalytic oxidation of carbendazim on the composite modified electrode, and it is demonstrating a linear range of 0.125 to 23.875 – 33.81 to 131.375 µM with a remarkably limit of detection of 0.00612 µM. The EuVO 4 /f-CNF /GCE also showcased an excellent degree of stability, retaining 96.5 % of its initial activity even after 30 days. This research highlights the potential of EuVO 4 /f-CNF modified GCEs as robust, and efficient platform for the carbendazim detection under electrochemical approach. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aimed to assess the microstructure, chemical composition, and image quality of different photostimulable phosphor plates (PSP). Four PSP systems, Express®, Digora®, VistaScan®, and Apixia,® were assessed. Five radiographs of a homogeneous acrylic phantom were obtained with the PSP of each system, to acquire a total of 20 images. The images were objectively evaluated for uniformity using mean grey and standard deviation (SD) of their grey values. PSP receptors were analyzed using scanning electron microscopy (SEM) to determine the thickness of the granule layer and the size of the granules. The chemical composition of the PSP receptors was analyzed using total reflection X-ray fluorescence (TXRF). VistaScan showed more uniform and higher density images than the other tested systems (p < 0.05), as well as the lowest SD of grey values (p < 0.05). Regarding the microstructure of the receptors, Digora and VistaScan had thicker granule layers than Express and Apixia, and VistaScan had smaller granules than Digora and Express (p < 0.05). Fourteen chemical elements were detected in the receptors, with barium being the element with the highest concentration in all PSP systems. The microstructure, chemical composition, and image quality varied among all four PSP receptors studied. VistaScan receptors showed the smallest variation in granule size, one of the thickest granule layers, and the most uniform and least noisy images. [ABSTRACT FROM AUTHOR]

In this research, theEu/TiO2composite coatings were formed in Na2H2PO4+ KOH + Eu2O3by plasma electrolytic oxidation (PEO) technology with different voltages. The morphology, composition and photocatalytic performance of the coatings were investigated. Surface morphology results showed that the micropores decreased on quantity with the increasing voltage. XRD showed the Eu/TiO2 coatings are composed of anatase and rutile phase and the anatase content first increased and then decreased with the increasing voltage. XPS indicated that Ti2p spin-orbit components of the Eu/TiO2 composite coatings are shifted towards higher binding energy, compared with the pure TiO2 coating, suggesting that some of the Eu3+ ions are incorporated into TiO2 lattice.The photocatalytic experiment results showed that the Eu/TiO2 composite coatings are of higher photocatalytic activity than that of the pure TiO2 coatings. Besides, with moderate amountEu3+ is of positive effect on increasing the photocatalytic activity of Eu/TiO2 compositecoatings. [ABSTRACT FROM AUTHOR]

Separation of the adjacent lanthanide (Ln) pair such as Sm-Eu from each other using chemical methods is difficult due to their similar chemical features. In the present work, electrochemical separation of Eu and Sm from each other were studied in molten LiCl-KCl-1 wt% EuCl3-1 wt% SmCl3 at 500 °C. By using a Cu reactive electrode, Sm was selectively separated from the salt because of the formation of several Cu-Sm intermetallic compounds while Eu remained in the salt. The formation of Al-Eu compounds occurs at a more negative potential than that of the Al-Sm compounds on Al electrode. However, the formation rate of Al-Eu compound is much higher than that of Al-Sm compound. With an electrolysis time of 0.5 h and a potential at -2.225 V (vs Ag(I)/Ag), the deposit on the electrode is mainly made up of Al-Eu compound. This study reveals the influence of working electrode on Eu-Sm separation and provides a potential method for adjacent lanthanide pair separation. [ABSTRACT FROM AUTHOR]

Polymers involved as adsorbent materials during Eu(III) removal tests were prepared by functionalization of a natural polymer – cellulose, and a commercial one represented by Amberlite XAD7. As extractant, we used tetrabutil ammonium di-hydrogen phosphate (TBAH2P) which is a cheap and environmentally friendly product. Impregnated polymers using a rotavapor system in which the quaternary ammonium salt used as extractant was concentrated on to the used polymer. Later obtained materials were characterized by Fourier Transformed Infrared Spectroscopy (FTIR) and X-Ray electron dispersion (EDX). During experimental test we determine pH, contact time, Eu(III) initial concentration and temperature effect on the functionalized polymers adsorption capacity. Therewith for both functionalized polymers, a comparison was made between the adsorption process characteristics based on kinetics and thermodynamic studies. [ABSTRACT FROM AUTHOR]

LnPO 4 :Eu3+ (Ln = La, Gd and Y) nanoparticles (NPs) were prepared at low temperatures via a urea-based thermal decomposition method. X-ray diffraction pattern revealed a hexagonal single phase, high purity with an average crystalline size of 13.9, 14.89, and 18.7 nm for LaPO 4 :Eu, GdPO 4 :Eu, and YPO 4 :Eu NPs, respectively. Bandgap energies were calculated based on the measure absorption spectra are to be values 5.14, 5.03, and 4.90 eV for the LaPO 4 :Eu, GdPO 4 :Eu, and YPO 4 :Eu NPs, respectively. A comparative study suggested that the excitation and emission transitions were significantly higher in the GdPO 4 :Eu NPs and in comparison to the LaPO 4 :Eu and YPO 4 :Eu NPs. It implies the impact of the crystallinity, host lattice, and crystal symmetry, in which doped Eu3+-ion replaces the host cation and distorts the crystal symmetry. [ABSTRACT FROM AUTHOR]

One of the most important reasons for the controversy over the development of nuclear energy is the proper disposal of spent fuel. Separation of actinide and lanthanide ions is an important part of safe long-term storage of radioactive waste. Herein, a three-dimensional (3D) graphene-based macrostructure (GOCS) was utilized to remove actinide thorium and lanthanide europium ions from aqueous solutions. The adsorption of Eu(III) and Th(IV) on the GOCS was evaluated as a function of adsorption time, solution pH, initial ion concentrations, and ionic strength. The experimentally determined maximum adsorption capacities of this GOCS for Eu(III) (pH 6.0) and Th(IV) (pH 3.0) are as high as 150 and 220 mg/g, respectively. By using Fourier transformation infrared (FT-IR), X-ray photoelectron (XPS), and extended X-ray absorption fine structure (EXAFS) spectroscopy, we concluded that the Eu(III) and Th(IV) adsorption was predominantly attributed to the inner-sphere coordination with various oxygen- and nitrogen-containing functional groups on GOCS surfaces. Our selective adsorption results demonstrate that the actinide and lanthanide ions can be effectively separated from transition metal ions. This study provides new clues to the overall recycling of actinide and lanthanide ions in radioactive environmental pollution treatments. Image 1 • Adsorption capacities for Eu(III) and Th(IV) are as high as 150 mg/g at pH 6.0 and 220 mg/g at pH 3.0, respectively. • Highly selective adsorption of actinide and lanthanide ions from mixed solution could be realized under acidic conditions. • The inner-sphere surface complexation by -COO-, -OH, and -NH 2 was revealed by utilizing batch experiments and spectroscopy. The three-dimensional graphene-based GOCS macrostructure has a superior selective adsorption ability for lanthanide and actinide ions. [ABSTRACT FROM AUTHOR]

Microorganisms show a high affinity for trivalent actinides and lanthanides, which play an important role in the safe disposal of high-level radioactive waste as well as in the mining of various rare earth elements. The interaction of the lanthanide Eu(III) with the sulfate-reducing microorganism Desulfosporosinus hippei DSM 8344T, a representative of the genus Desulfosporosinus that naturally occurs in clay rock and bentonite, was investigated. Eu(III) is often used as a non-radioactive analogue for the trivalent actinides Pu(III), Am(III), and Cm(III), which contribute to a major part of the radiotoxicity of the nuclear waste. D. hippei DSM 8344T showed a weak interaction with Eu(III), most likely due to a complexation with lactate in artificial Opalinus Clay pore water. Hence, a low removal of the lanthanide from the supernatant was observed. Scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy revealed a bioprecipitation of Eu(III) with phosphates potentially excreted from the cells. This demonstrates that the ongoing interaction mechanisms are more complex than a simple biosorption process. The bioprecipitation was also verified by luminescence spectroscopy, which showed that the formation of the Eu(III) phosphate compounds starts almost immediately after the addition of the cells. Moreover, chemical microscopy provided information on the local distribution of the different Eu(III) species in the formed cell aggregates. These results provide first insights into the interaction mechanisms of Eu(III) with sulfate-reducing bacteria and contribute to a comprehensive safety concept for a high-level radioactive waste repository, as well as to a better understanding of the fate of heavy metals (especially rare earth elements) in the environment. • First investigation of the interactions of a sulfate-reducing bacterium with Eu(III). • Bioprecipitation of Eu(III) on the cell surface. • Fast onset of Eu(III) phosphate formation. • Use of chemical microscopy for spatially-resolved Eu(III) speciation. [ABSTRACT FROM AUTHOR]

• Fourier transform (FT) spectra were used to extend the study of the hyperfine structure (HFS) of Eu I and Eu II energy levels. • HFS constants of 29 levels and isotope shifts (IS) of 30 transition lines for Eu I from 17707.42 to 47373.10 cm−1 were determined, of which HFS constants of 22 levels and IS of 24 transition lines are reported for the first time, as far as we know. • HFS constants of 15 levels and IS of 19 transition lines for Eu II from 1669.21 to 56271.40 cm−1 were determined, of which the HFS constants of 8 levels and IS of 8 transition lines are reported for the first time, as far as we know. The magnetic dipole hyperfine structure (HFS) constants A of neutral and singly ionized europium (Eu I and Eu II) were determined using the emission spectra recorded by the Fourier transform spectrometer at the National Solar Observatory (NSO) at the Kitt Peak, USA. The HFS constants of 29 levels of Eu I and 15 levels of Eu II were determined, from which 22 results for Eu I and 8 results for Eu II are reported for the first time, as far as we know. The isotope shifts (ISs) of 30 transitions of Eu I and 19 transitions of Eu II were also determined, and the ISs of 22 transitions of Eu I and 8 transitions of Eu II are reported for the first time. This work increases the total number of levels with experimentally determined HFS constants A to 202 for Eu I and 24 for Eu II, and increases the number of transitions with known ISs to 359 for Eu I and 36 for Eu II. [ABSTRACT FROM AUTHOR]

Herein, Eu(III) retention mechanism and microstructure on δ-MnO 2 as a function of solution pH were studied using both the conditional macroscopic method and molecular-level high resolution EXAFS technique with a bent crystal analyzer. The results suggested that the sorption Eu(III) onto δ-MnO 2 was strongly dependent on pH but not on ionic strength, implying the formation of inner-sphere surface complexation for Eu(III) on δ-MnO 2 surface. Molecular-level results from EXAFS methods showed that Eu was surrounded by ∼8O atoms in first coordination shell at R Eu-O  ≈ 2.42 Å, and second shell of Mn atoms at R Eu-Mn  ≈ 3.91 Å was found in four sorption samples from different solution pH. All this results reflected the formation of a bidentate surface complex with Eu(III) bonding by corner sharing to MnO 6 -octahedron on δ-MnO 2 surface. Both the macroscopic findings and microstructure of Eu(III) at the δ-MnO 2 -water interface enhance our understanding for the reaction dynamics and states of Eu(III) and related radionuclides in natural environment. [ABSTRACT FROM AUTHOR]

This work reports on the effective sequestration of Eu(III) ions from aqueous solutions using three types of metal-organic frameworks (MOFs) constructed from benzene-1,3,5-tricarboxylic acid (H 3 BTC) linker and Ca2+, Cu2+, or Al3+ metal nodes. The MOFs possessed an exceptionally high Eu adsorption capacity of 635 (91% removal), 642 (92% removal), and 628 mg g−1 (90% removal) for Cu-BTC, Ca-BTC, and Al-BTC, respectively, at pH 7 for an initial Eu concentration of 350 mg L−1. The MOFs were hydrolytically stable and possessed a high Eu adsorption capacity in a wide pH range of 4–8. While the pseudo-second-order model explained the adsorption kinetics, the adsorption process followed the Langmuir-Freundlich isotherms. The analysis confirmed that the Eu adsorption process was governed by chemical interactions between the carboxylic acid/carboxylate group and Eu(III) ions via complexation or ion exchange mechanism. A multi-metal adsorption study confirmed a preferential adsorption behaviour for trivalent lanthanides over divalent cations due to comparatively stronger interactions between Ln3+ ions and carboxylate groups. The XPS findings suggested Eu−OOC and Eu(OH) 3 formed over the MOFs' surface after Eu adsorption. These MOFs were effectively regenerated for multiple cycles using 0.1 mol L−1 EDTA solution. Thus, the study demonstrated low-cost MOFs with superior regeneration capabilities for the capture of Eu(III) ions from waste solutions. • Hydrolytically stable Ca, Cu, and Al MOFs were studied for Eu recovery between pH 4–8. • Cu-BTC, Ca-BTC, and Al-BTC adsorbed 635, 642, and 628 mg of Eu per g of MOF at pH 7. • Eu(III) adsorption occurred via complexation and cation-exchange mechanism. • The MOFs were regenerable for five adsorption-desorption cycles using 0.1 mol L−1 EDTA solution. [ABSTRACT FROM AUTHOR]

α-Ti(HPO 4 ) 2 ·H 2 O (α-TiP) and its propylamine intercalation product, Ti(HPO 4 ) 2 ·2C 3 H 7 NH 2 ·H 2 O (α-TiPPr), have been synthesized and characterized. Later, their sorption capacity for europium(III) was investigated, and this purpose was accomplished by treating α-TiP and α-TiPPr with europium(III) nitrate solutions at different concentrations until the equilibrium is reached. All samples were characterized, among others, by powder X-ray diffraction (PXRD), scanning and transmission electron microscopies (SEM, TEM, STEM-EDX, SAED), thermogravimetric analysis (TGA), and photoluminescence (PL) measurements. The results show that the Eu 3+ uptake is limited to surface when α-TiP is used as sorbent. Nevertheless, the Eu-retention is considerably enhanced with α-TiPPr as a consequence of an ion-exchange process into the interlayer space of the layered titanium phosphate (involving propylammonium cations, C 3 H 7 NH 3 + , and hexahydrate europium(III) species, [Eu(H 2 O) 6 ] 3+ ), and the crystal structure of a hypothetical final product, α-[Eu(H 2 O) 6 ] 2/3 Ti(PO 4 ) 2 ·[(H 2 O) 6 ] 1/3 , has been proposed by using DFT calculations. [ABSTRACT FROM AUTHOR]

Fluorescent molecular imaging technique has been actively explored for optical image-guided cancer surgery in pre-clinical and clinical research and has attracted many attentions. However, the efficacy of the fluorescent image-guided cancer surgery can be compromised by the low signal-to-noise ratio caused by the external light excitation. This study presents a novel nanoparticle-mediated radiopharmaceutical-excited fluorescent (REF) image-guided cancer surgery strategy, which employs the internal dual-excitation of europium oxide nanoparticles through both gamma rays and Cerenkov luminescence emitted from radiopharmaceuticals. The performance of the novel image-guided surgery technique was systematically evaluated using subcutaneous breast cancer 4 T1 tumor models, orthotropic and orthotropic-ectopic hepatocellular carcinoma tumor-bearing mice. The results reveal that the novel REF image-guided cancer surgery technique exhibits high performance of detecting invisible ultra-small size tumor (even less than 1 mm) and residual tumor tissue. Our study demonstrates the high potential of the novel image-guided cancer surgery for precise tumor resection. [ABSTRACT FROM AUTHOR]

Biodegradable zinc oxide nanoparticles (ZnO NPs) are considered promising materials for future biomedical applications. To fulfil this potential, biodistribution and elimination patterns of ZnO NPs in the living organism need to be resolved. In order to investigate gastrointestinal absorption of ZnO NPs and their intra-organism distribution, water suspension of ZnO or fluorescent ZnO:Eu (Europium-doped zinc oxide) NPs (10 mg/ml; 0.3 ml/mouse) was alimentary-administered (IG: intra-gastric) to adult mice. Internal organs collected at key time-points after IG were evaluated by AAS for Zn concentration and analysed by cytometric techniques. We found that Zn-based NPs were readily absorbed and distributed (3 h post IG) in the nanoparticle form throughout the organism. Results suggest, that liver and kidneys were key organs responsible for NPs elimination, while accumulation was observed in the spleen and adipose tissues. We also showed that ZnO/ZnO:Eu NPs were able to cross majority of biological barriers in the organism (including blood–brain-barrier). [ABSTRACT FROM AUTHOR]

The size, shape and chemical composition of europium (Eu 3+ ) cobalt ferrite (CFEu) nanoparticles were optimized for use as a “multimodal imaging nanoprobe” for combined fluorescence and magnetic resonance bioimaging. Doping Eu 3+ ions into a CF structure imparts unique bioimaging and magnetic properties to the nanostructure that can be used for real-time screening of targeted nanoformulations for tissue biodistribution assessment. The CFEu nanoparticles (size ∼7.2 nm) were prepared by solvothermal techniques and encapsulated into poloxamer 407-coated mesoporous silica (Si-P407) to form superparamagnetic monodisperse Si-CFEu nanoparticles with a size of ∼140 nm. Folic acid (FA) nanoparticle decoration (FA-Si-CFEu, size ∼140 nm) facilitated monocyte-derived macrophage (MDM) targeting. FA-Si-CFEu MDM uptake and retention was higher than seen with Si-CFEu nanoparticles. The transverse relaxivity of both Si-CFEu and FA-Si-CFEu particles were r 2 = 433.42 mM −1 s −1 and r 2 = 419.52 mM −1 s −1 (in saline) and r 2 = 736.57 mM −1 s −1 and r 2 = 814.41 mM −1 s −1 (in MDM), respectively. The results were greater than a log order-of-magnitude than what was observed at replicate iron concentrations for ultrasmall superparamagnetic iron oxide (USPIO) particles (r 2 = 31.15 mM −1 s −1 in saline) and paralleled data sets obtained for T 2 magnetic resonance imaging. We now provide a developmental opportunity to employ these novel particles for theranostic drug distribution and efficacy evaluations. Statement of Significance A novel europium (Eu 3+ ) doped cobalt ferrite (Si-CFEu) nanoparticle was produced for use as a bioimaging probe. Its notable multifunctional, fluorescence and imaging properties, allows rapid screening of future drug biodistribution. Decoration of the Si-CFEu particles with folic acid increased its sensitivity and specificity for magnetic resonance imaging over a more conventional ultrasmall superparamagnetic iron oxide particles. The future use of these particles in theranostic tests will serve as a platform for designing improved drug delivery strategies to combat inflammatory and infectious diseases. [ABSTRACT FROM AUTHOR]

For the reliable safety assessment of repositories of highly radioactive waste, further development of the modelling of radionuclide migration and transfer in the environment is necessary, which requires a deeper process understanding at the molecular level. Eu(III) is a non-radioactive analogue for trivalent actinides, which contribute heavily to radiotoxicity in a repository. For in-depth study of the interaction of plants with trivalent f elements, we investigated the uptake, speciation, and localization of Eu(III) in Brassica napus plants at two concentrations, 30 and 200 µM, as a function of the incubation time up to 72 h. Eu(III) was used as luminescence probe for combined microscopy and chemical speciation analyses of it in Brassica napus plants. The localization of bioassociated Eu(III) in plant parts was explored by spatially resolved chemical microscopy. Three Eu(III) species were identified in the root tissue. Moreover, different luminescence spectroscopic techniques were applied for an improved Eu(III) species determination in solution. In addition, transmission electron microscopy combined with energy-dispersive X-ray spectroscopy was used to localize Eu(III) in the plant tissue, showing Eu-containing aggregates. By using this multi-method setup, a profound knowledge on the behavior of Eu(III) within plants and changes in its speciation could be obtained, showing that different Eu(III) species occur simultaneously within the root tissue and in solution. [Display omitted] • Plants accumulate the lanthanide Eu and influence its speciation. • Eu is mainly localized in the roots, and occurs only in traces in shoots and leaves. • Eu is immobilized in plant roots in the form of aggregates and precipitates. • Three Eu(III) species could be detected spatially resolved by chemical microscopy. [ABSTRACT FROM AUTHOR]

Fluorescent europium-doped nanohydroxyapatite (Eu-nHA, 5 at.% Eu) was prepared by a precipitation method followed by annealing at 600 °C. Transmission electron microscopy and X-ray diffraction analyses reveal the nanocrystalline nature of the annealed Eu-nHA particles, which are 20–40 nm in width and 40–60 nm in length. Elements of Ca, P, O and Eu are detected by energy dispersive X-ray analysis. Upon excitation by 250 nm ultraviolet light, the annealed Eu-nHA (Eu-nHAa) nanoparticles display strong pinkish-red luminescence in the fluorescence spectrum. Moreover, the Eu-nHAa powder shows green and red colours by the irradiations of blue and green lights, respectively. Thein vitrocell proliferation assessment and the lactate dehydrogenase activity assay indicate that the Eu-nHAa nanoparticles with the concentrations of 0.3, 3 and 30 μg/ml have inhibitory effects on human umbilical vein endothelial cells in a dose- and time-dependent manner. The fluorescent Eu-nHAa nanomaterial would have potential applications in bio-labelling and anti-angiogenesis of tumors. [ABSTRACT FROM PUBLISHER]

The removal and recovery of critical rare-earth elements (REEs) are important from an environmental and economic perspective. The recovery of critical metals from secondary sources has received considerable attention. This work aims to evaluate the beads produced from sericin, alginate, and poly(ethylene glycol) diglycidyl ether (SA@PEGDGE) to recover Eu3+. The pH effect showed that pH 5.0 had the highest uptake of Eu3+ (0.289 ± 0.006 mmol/g) with stoichiometric cationic exchange with Ca2+ (0.425 ± 0.023 mmol/g) by SA@PEGDGE. The kinetic (pseudo-first order, pseudo-second order, and external diffusion) and equilibrium (Langmuir) models adequately represented the adsorption results. The particles had an increase in adsorptive capacity from 0.555 mmol/g at 25 °C to 0.633 mmol/g at 55 °C. Hydrochloric acid (0.1 mol/L) showed the highest recovery rate of Eu3+ (96.50 ± 0.84%) from SA@PEGDGE. Eu3+ recovery was highly successful for five cycles. The recovery was greater than 95% and the reuse of the eluent in the adsorption cycles enriched the Eu3+ concentration 10-fold, from 1.07 mmol/L to 9.96 mmol/L. The SA@PEGDGE also showed better performance for biosorption of Eu3+ with other competing ions. The characterization analyzes showed that the SA@PEGDGE beads produced by the ionotropic gelation technique have a spherical shape, surface with low roughness, and amorphous character. The mechanisms of Eu3+ biosorption involved interactions with the functional groups present on the SA@PEGDGE surface, cation exchange, and electrostatic interactions. Thus, the crosslinked sericin/alginate particles can be a sustainable alternative for the recovery of critical REEs from wastewater, resulting in social and economic benefits from a circular economy. [Display omitted] • PEGDGE- crosslinked sericin/alginate blend by is effective in recovering europium. • Cationic exchange mechanisms between Eu3+ and Ca2+ are involved in biosorption. • The maximum capacities are: 0.555 (25 °C), 0.608 (40 °C) and 0.633 mmol/g (55 °C). • Regeneration: Reuse of eluent-enriched europium (up to 10-fold) after 5 cycles. • Selectivity: Eu3+ was preferentially removed from multicomponent systems. [ABSTRACT FROM AUTHOR]

The innovative (i-) SANEX process for the separation of minor actinides from PUREX highly active raffinate is expected to employ a solvent phase comprising 0.2M TODGA with 5 v/v% 1-octanol in an inert diluent. An initial extract / scrub section would be used to extract trivalent actinides and lanthanides from the feed whilst leaving other fission products in the aqueous phase, before the loaded solvent is contacted with a low acidity aqueous phase containing a sulphonated bis-triazinyl pyridine ligand (BTP) to effect a selective strip of the actinides, so yielding separate actinide (An) and lanthanide (Ln) product streams. This process has been demonstrated in lab scale trials at Jülich (FZJ). The SACSESS (Safety of ACtinide SEparation proceSSes) project is focused on the evaluation and improvement of the safety of such future systems. A key element of this is the development of an understanding of the response of a process to maloperations. It is only practical to study a small subset of possible maloperations experimentally and consideration of the majority of maloperations entails the use of a validated dynamic model of the process. Distribution algorithms for HNO 3 , Am, Cm and the lanthanides have been developed and incorporated into a dynamic flowsheet model that has, so far, been configured to correspond to the extract-scrub section of the i-SANEX flowsheet trial undertaken at FZJ in 2013 1 . Comparison is made between the steady state model results and experimental results. Results from modelling of low acidity and high temperature maloperations are presented. [ABSTRACT FROM AUTHOR]

Extraction of 241 Am and 152 Eu from carbonate-alkaline medias with solutions of functionalized calix[4]arenes and their nonmacrocyclic analogs in m -nitrobenzotrifluoride was studied. The dependencies of the Am distribution ratios on pH of the aqueous phase in the range 10 -13.5 and on the position and nature of functional groups in the calixarene core were examined. The composition of extractable solvates of americium with functionalized calix[4]arenes was determined. Thiacalixarenes extract americium more efficiently from alkaline solutions, as compared to calixarenes, demonstrating higher Am/Eu separation factor. Functionalization of the calixarenes improves the Am extraction efficiency and Am/Eu separation factor as well. In the case of thiacalixarenes, functionalization considerably decreases the extraction efficiency and selectivity. [ABSTRACT FROM AUTHOR]

Structures, morphologies, and properties of europium doped zinc silicate were characterized using X-ray diffractometer, Field emission scanning electron microscope, Fourier transform infrared spectrometer, and UV-vis spectrophotometer. The density of doped zinc silicate shows the trend of increment when the sintering temperature increases. The XRD pattern shows that the material was highly crystalline, having sharp peaks, while the FESEM image reveals the presence of densely packed grains as sintering temperature increased 600 ̊C up to 1000 ̊C. The increase of transmission band intensities at 3443, 1630, 980, 650, 530 cm -1 confirmed the crystallization of Zn 2 SiO 4 crystal in the glass matrix with increasing sintering temperature. Lastly, the increment of energy band gap after sintering temperature at 900 ̊C was related to the stabilization of α-Zn 2 SiO 4 phase in material. [ABSTRACT FROM AUTHOR]

In this study, Eu3+doped Y2O3(Y2O3: Eu3+) phosphor target was deposited on quartz fibre substrates by electron beam evaporation technology, and then the deposited fibres were annealed at different temperatures from 600 to 1000°C. Particle shape was changed, and particle size of Y2O3: Eu3+was increased with the rise in annealing temperature. Crystallisation and luminescent intensity of the deposited films on quartz fibres were significantly improved by annealing treatment. The most effective crystallisation and the maximum luminescent efficiency of the thin films were obtained when the deposited fibres were treated at 1000°C for 1 h. The luminescent property results indicated that the particle shape, particle size and crystallisation were the important factors affecting luminescent intensity of the deposited fibres. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide-supported nanoscale zerovalent iron (NZVI@rGO) composites were synthesized towards the uptake of europium (Eu(III)) in environmental cleanup. In this study, the effect of environmental factors on the uptake of Eu(III) from aqueous solutions on NZVI@rGO composites was investigated under ambient conditions by batch techniques. The uptake kinetics indicated that the uptake of Eu(III) on NZVI@rGO composites can be satisfactorily fitted by pseudo-second order kinetic model. The uptake of Eu(III) on NZVI@rGO composites was independent of ionic strength at pH > 5.0, indicating that inner-sphere surface complexation dominated the uptake of Eu(III) on NZVI@rGO composites. It is demonstrated that the maximum uptake capacities of NZVI@rGO composites for Eu(III) calculated from Langmuir models was 96.675 mg/g at pH 5.0 and T = 293 K. The thermodynamic parameters indicated that the uptake of Eu(III) on NZVI@rGO composites was an endothermic and spontaneous process. Based on surface complexation modeling, the diffuse layer model gave an excellent fits to the uptake of Eu(III) on NZVI@rGO composites with cation exchange complexes (X 3 Eu species) at pH < 4.5, mononuclear and monodentate complexes (SOEu 2+ species) at pH 5.0–7.0, and mononuclear and bidentate complexes ((SO) 2 Eu(OH) 2 − species) at pH > 7.0, respectively. The results indicated that NZVI@rGO composites can be considered as a promising adsorbent for the uptake of trivalent radionuclides from wastewaters in environmental cleanup. [ABSTRACT FROM AUTHOR]

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Calcium stannates (Ca 2 SnO 4 ), which has an inverse spinel structure, was adopted as the host material of emitting phosphor. Eu2O3–doped Ca 2 SnO 4 (Ca 2 SnO 4 :xEu, 0.00-0.08) were prepared by solid-states reaction at 1350 °C under atmospheric air with constant dwell time of 6 The Rietveld analysis of the X-ray powder diffraction (XRD) was used for lattice parameters calculations and the XRD pattern results show that there was no phase transformation observed for all sintered Ca 2 SnO 4 : xEu 3+ samples. Presence of Eu 2 O 3 also improved sinterability of the produced ceramics as evidenced by their SEM micrographs. Luminescent spectra acquired at room temperature of all samples were observed in a broad range of a visible light wavelength region under ultraviolet light excitation. The ceramic samples produced by the present study showed the most intense light emission in the red light region. [ABSTRACT FROM AUTHOR]

[Display omitted] • The stability, structure, electronic properties of nano clusters of Germanium and Europium atom doped germanium clusters with n = 2 to 12, 15 and 20 were calculated. • The ionization energies and photoelectron spectra were performed Ge n and EuGe n-1. • Shape of molecular orbitals (MO) involved in the ionization process for each structure were showed and interpreted. • Then NBO calculations were done for determine the effective molecular orbitals in the ionization and in order to study the electron density on the nanoclusters. • Addition of Eu as an impurity atom doped in pure Ge n clusters reduce the ionization energy. This study explored the geometric, electronic, and spectral properties of germanium and Eu-doped germanium clusters and compared their simulated PES spectra. The stability of Ge n and EuGe n nanoclusters was examined with density functional theory using FHI-aims as a software package. Symmetry-adapted cluster-configuration interaction general-R (SAC-CI-General-R) method and the SDD basis set were adopted to determine ionization energies and calculate their intensities. Natural bond orbital (NBO) calculations were performed to determine the effective molecular orbitals in the ionization and study the electron density on the nanoclusters. The shape of molecular orbitals (MO) involved in the ionization process for each structure was displayed and interpreted. The analyses of binding energies showed that increasing the size of nanoclusters leads to more stability for nanoclusters. Ionization energy and the photoelectron spectrum of these clusters indicated that Eu as an impurity reduces ionization energy and shifts the ionization processes towards infrared wavelengths. Interestingly, pure and doped clusters followed a similar pattern in terms of an increase/decrease in the first ionization energy compared to n-1 and n + 1 clusters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Comparative study of americium and europium complexation with BTPhen-CH was done. • Both pure cation and its tetraaquatrinitrato complex were used as reactants. • Five different reactions were studied. • In case of pure cation europium forms the more stable complexes. • In case of tetraaquatrinitrato complex americium form the more stable complexes. 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenantroline (BTPhen) based ligands have shown great promise in separation of trivalent lanthanides and actinides. Although many experimental studies have shown that americium is forming stronger complexes with the BTPhen ligands than europium, most theoretical studies have thus far failed to reproduce these results. In the current study, two different metal forms (the naked cation and its tetraaquatrinitrato complex) were used to study five different complexation reactions. It was shown that in case of naked cations europium forms the most stable complex with the 2,9-bis(1,2-diazin-3-yl)-1,10-phenanthroline (BTPhen-CH) ligand in all of the compared reactions. In case of tetraaquatrinitrato complex it was shown that europium gets a higher stabilizing effect and thus americium complexes with BTPhen-CH become the more stable form, as can be seen in the experimental studies. [ABSTRACT FROM AUTHOR]