Search Results (458)

This study primarily aimed to evaluate how the chemical form and carrier medium of radionuclide contamination influence the effectiveness of skin decontamination procedures. In addition, the study sought to identify decontamination strategies that align with recommended practices while reducing reliance on intensive mechanical cleaning methods. Although skin damage was not directly evaluated, the findings provide valuable information for improving the safety of decontamination procedures used by personnel handling radioactive materials and by emergency responders involved in radiological and CBRN (Chemical, Biological, Radiological, and Nuclear) incidents. Accidental spills of radiopharmaceuticals in laboratories and medical facilities, as well as contamination associated with uranium mining, fuel-cycle operations, spent fuel management, and the decommissioning of nuclear facilities, may involve radioactive isotopes present in a variety of chemical forms and solutions. Fresh porcine skin was used as an experimental model, and skin temperature was maintained at 37 °C to simulate physiological conditions. Europium-152 (¹⁵²Eu) was selected as the model radionuclide. Deionized water, concentrated nitric acid (HNO₃), saturated sodium hydroxide (NaOH) solution, and ethanol were used as carrier media representing different chemical environments of ¹⁵²Eu contamination. To simulate realistic contamination scenarios, contaminating solutions were allowed to dry on the skin surface before decontamination. The influence of contaminant chemistry, carrier medium, and drying conditions on radionuclide penetration and subsequent decontamination effectiveness was investigated. Particular attention was given to the extent to which different physicochemical forms of contamination affected radionuclide removal from the skin. The results demonstrated that the chemical form of the contaminant and the drying conditions were key factors determining decontamination efficiency. Among the tested methods, a decontamination kit consisting of a soap-based solution, the complexing agent DTPA, and an absorbent non-woven swab achieved the highest radionuclide removal efficiency. These findings indicate that successful radionuclide decontamination depends strongly on the physicochemical properties of the contaminant. The combined use of a complexing agent, detergent-based formulation, and absorbent material can significantly enhance radionuclide removal from contaminated skin surfaces. Furthermore, the study highlights the importance of considering contaminant chemistry when developing effective and safe decontamination protocols for radiological and CBRN incidents. Full article

This article reports on the synthesis and characterization of the properties of ceramic powders and aerogels of rare earths using the Sc₂O₃:Eu₂O₃ system synthesized through the sol–gel method, as well as on the toxicological effects of the cytokinesis-block micronucleus cytome assay (CBMC). A sol–gel variant using epoxide-assisted gelling and supercritical CO₂ drying was employed to produce the aerogels. In vitro CBMCs were employed to assess the genotoxic and cytotoxic effects of the materials’ dosages and inherent properties. The morphology of the powders and aerogels consisted of agglomerates of irregularly shaped particles. At the same time, structural analysis revealed crystal sizes of 16 and 10 nm, respectively, for the ceramic powders and aerogels, in which microplastic deformations were observed. The cubic crystalline structure of the Sc₂O₃:Eu₂O₃ system remained unchanged. However, applying CBMC and observing the genotoxic and cytotoxic effects of the nanoparticles revealed that the main genotoxic xenobiotic agent was the aerogel. The primary mode of cellular death was necrosis, suggesting that reactive oxygen species might have been involved in the genotoxic and cytotoxic damage. Full article

The ionic conductivity of EuCl₂ was investigated at high temperatures, including the melting point. Measurements were performed on polycrystalline specimens obtained by the solidification of the corresponding melt. The behavior of the conductivity and the apparent Arrhenius activation energy was characterized. It is suggested that the conductivity behavior results from anion sublattice disordering within the crystals up to the melting point. The variation in transport properties correlates well with the crystal structure of EuCl₂. The phase diagram of the LiCl–EuCl₂ binary system was constructed based on DSC measurements. This system was found to be a simple eutectic type featuring the incongruently melting compound LiEu₃Cl₇. The CALPHAD method was employed for thermodynamic modeling, incorporating both experimental and literature data for the LiCl–EuCl₂ system. Full article

Rare-earth vanadates constitute an important class of functional materials with potential applications as luminophores, in optoelectronics and catalysis. The research for this work was inspired by the incomplete literature data, including the synthesis, structure and physicochemical properties of europium(III) vanadate(V) with the general formula Eu₅VO₁₀. The primary goal of this work was to supplement the missing data about this compound and identify its potential applications. This compound was synthesized using three methods, including waste-free methods: ceramic, mechanochemical and a modified Pechini method. The obtained Eu₅VO₁₀ was characterized using XRD, DTA–TG, FTIR, UV–Vis–DRS, SEM and gas pycnometry. It was settled that Eu₅VO₁₀ crystallizes in the monoclinic system and is thermally stable up to a temperature of approximately 1310 °C, above which it decomposes in the solid phase. Estimated energy gap (E_g) values ranged from ~3.21 eV to ~3.53 eV depending on the synthesis method used, allowing Eu₅VO₁₀ to be classified as a wide-bandgap electrical semiconductor. The results also showed that the synthesis method affects the crystallite size of the synthesized compound. The development of synthesis methods and characterization of Eu₅VO₁₀ expands our understanding of rare-earth vanadates and their potential applications as functional materials. Full article

The development of highly sensitive luminescence sensing materials has attracted much attention in recent years. In this study, a new two-dimensional porous europium metal–organic framework (EuMOF, [Eu(DHDA)₁.₅·3H₂O]_n; DHDA = 2,2-dihydroxyacetic acid) is obtained, characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), luminescence, and Fourier transform infrared spectroscopy (FT-IR). At the best excitation at 295 nm, EuMOF shows red luminescence (CIE: 0.6255, 0.3740) and has four obvious peaks at 582, 605, 641, and 689 nm, which are due to ⁵D₀ → ⁷F₁, ⁵D₀ → ⁷F₂, ⁵D₀ → ⁷F₃, and ⁵D₀ → ⁷F₄ transitions, respectively. Studies have shown that EuMOF is a stable, fast-responding, and highly sensitive luminescence sensor for isoprocarb and levofloxacin (Lvx) in aqueous solutions, apple peel and rice extract solutions, and real urine, which are closely associated with food safety and human health. The sensing behavior toward isoprocarb and Lvx may be attributed to the specific binding of the two analytes to EuMOF. The sensing of isoprocarb is a dynamic luminescence-quenching process, while that of Lvx is a dynamic luminescence-enhancing process. The limits of detection (LOD) for isoprocarb and Lvx are as low as 1.0 and 0.5 nM, respectively, which are much lower than the Chinese national standard (GB 28260-2011, 2.583 μM). EuMOF also demonstrates strong anti-interference detection of isoprocarb in apple peel and rice extract solutions, as well as Lvx in real urine, with excellent detection stability in a 0.01~9.0 nM range. The recovery rates for isoprocarb and Lvx in real samples are 99.12%~101.25%. This work provides the first bifunctional lanthanide sensor for pesticides and antibiotics. Full article

Luminescent gadolinium oxide nanoparticles doped with europium were synthesized through a precipitation reaction using gadolinium and europium nitrates as precursors. The europium-doped gadolinium oxide nanoparticles were incorporated first into a gel matrix of silicon dioxide and second by mixing with polymethyl methacrylate. Both processes are synthesized by the simultaneous hydrolysis of tetraethyl orthosilicate and polymerization of 3-(Trimethoxysilyl) propyl methacrylate. The solid samples obtained are round in shape with a size of about 2.5 cm, which makes the material easy to handle to test different applications. The inclusion of Gd₂O₃:Eu³⁺ nanoparticles increases the level of absorbance in the ultraviolet region, which allows for the improved emission of the material at a wavelength of around 610 nm. Furthermore, it enables easy doping of the material and the fabrication of thin films and monoliths with potential optical applications. Full article

Europium (Eu) is a rare-earth element with unique optoelectronic properties that underpin its applications in displays and lighting, X-ray imaging, anti-counterfeiting, and biomedicine. Conventional methods typically involve the synthesis of europium-based luminescent materials in powder or crystalline form via high-temperature solid-state reactions or solution processes, followed by secondary processing such as spin coating or evaporation to fabricate films or devices. In this work, we report a direct approach to prepare trivalent europium-based luminescent materials using divalent europium bromide (EuBr₂) as the precursor via a gas-phase vacuum evaporation approach (GPVEA). This “deposition-as-synthesis” method enables the fabrication of the hybrid nanoscale films with various blending ratios, which exhibit changes in the fine structure of the emission peaks. The luminescence spectra remain nearly identical across the temperature range from 80 K to 320 K. The photoluminescence emission intensity is stronger in air than in a vacuum. The films show a maximum photoluminescence quantum yield (PLQY) of 8.27% and good photostability, with an emission decay of 3.44% over 50 min under continuous 300 nm excitation. Through patterned design, we demonstrate their value for anti-counterfeiting applications. This work thus provides guidance for the preparation of europium-based luminescent nanomaterials via GPVEA and their application in anti-counterfeiting. Full article

This study demonstrates a single phosphor material system capable of continuously tuning color across the entire visible spectrum while integrating multiple luminescent functionalities. A series of these phosphors was conveniently synthesized with varying Al/Sr ratios in the reactants, enabling the emission color to progress through red, orange, yellow, green and blue. We systematically investigated the photoluminescence mechanisms by correlating crystal phase evolution with europium ion site occupancy and exploiting the resulting multicolor-emitting phosphors in optical display and anti-counterfeiting demonstrations. The relationships between composition, structure, and luminescence were revealed commendably, alongside more functional evaluations of europium-doped strontium aluminate phosphors. Notably, at an equimolar Al/Sr ratio of 1 (with 2 at% Eu doping), the phosphor achieves a high absolute quantum yield of 66.2% and functions as a luminescent optical thermometer with a relative sensitivity of 0.27% K⁻¹ and temperature resolution of ~0.005 K. At a non-equimolar Al/Sr ratio of 2, the Eu-doped phosphor exhibits efficient photothermal conversion, reaching ~72.8 °C under 980 nm laser irradiation (1 W·cm⁻²) within 10 s. This work introduces a facile composition-regulation strategy for designing multicolor-tunable, multifunctional phosphors, highlighting promising applications in optical displays, anti-counterfeiting, luminescence thermometry and photothermal conversion. Full article

Rare-earth hydroxycarbonates and oxycarbonates are attractive functional materials because their crystal chemistry and optical response can be tailored through controlled cation substitution. In this work, Eu-doped lanthanum hydroxycarbonates with nominal europium contents of 1, 3, and 5 mol% were synthesized by combining co-precipitation and hydrothermal treatment at 140 °C for 24 h and subsequently calcined at 500 °C for 0.5 h to obtain the corresponding oxycarbonates. X-ray diffraction showed that the as-synthesized powders consist of single-phase hexagonal LaCO₃OH, while the calcined products are single-phase La₂O₂CO₃. In both structural families, systematic peak shifts with increasing Eu content indicated the formation of homogeneous substitutional solid solutions. Thermal analysis revealed a clear two-step decomposition pathway for the hydroxycarbonate precursors, with endothermic events at about 530 and 850 °C, consistent with the sequential transformation from hydroxycarbonate to oxycarbonate and, finally, to oxide. UV-Vis absorption measurements highlighted a dopant-dependent shift in the absorption edge in both hydroxycarbonate and oxycarbonate systems. Kubelka–Munk analysis showed that the estimated band-gap energy increases with Eu content, from 4.9 to 5.4 eV for LaCO₃OH-based samples and from 4.7 to 5.1 eV for La₂O₂CO₃-based samples. These results demonstrate that europium incorporation is an effective strategy for tuning the structural evolution and optical properties of lanthanum carbonate-derived materials, thus supporting their potential use in UV-responsive rare-earth-based functional systems. Full article

This study investigates the geochemical behavior and transport mechanisms of Rare Earth Elements (REEs), Yttrium (Y), Zirconium (Zr), and Hafnium (Hf) in three natural water systems under reducing conditions: the Santa Barbara and Occhio dell’Abisso mud volcanoes and a sulphureous spring at Villafranca Sicula. A comprehensive fractionation approach was applied to isolate the truly dissolved fraction (TDF < 10 kDa), the colloidal fraction (10 kDa < CF < 450 nm), the suspended particulate matter (SPM > 450 nm), and the associated bottom sediments. Analytical results reveal that REE distribution is significantly influenced by redox conditions and solid–liquid interface processes. The absence of negative Cerium (Ce) anomalies and the presence of pronounced positive Europium (Eu) anomalies in the Santa Barbara and Occhio dell’Abisso waters suggest strongly reducing environments where Eu²⁺ stability is enhanced. Shale-normalized patterns indicate that, while SPM and sediment fractions often exhibit Middle REE (MREE) enrichment, linked to Mn-bearing and Fe-oxyhydroxide phases, the dissolved phase reflects dissolution processes governed by a non-CHARAC (CHarge-and-RAdius-Controlled) behavior. Furthermore, the study highlights a significant decoupling in the Zr/Hf and Y/Ho pairs. While these pairs remain coherent during magmatic processes, they undergo mutual fractionation in aqueous systems due to differential reactivity toward colloidal surfaces and organic ligands. Specifically, Zr/Hf ratios in the colloidal and dissolved fractions deviate from chondritic values, driven by the preferential scavenging of Hf onto mineral surfaces. These findings underscore the utility of REE and Zr-Hf systematics as high-resolution tracers for reconstructing water–rock interaction processes and elemental cycling in complex hydrological environments. Full article

This study aimed to develop a novel fluorescent sensor based on Eu³⁺ complex-doped protein crystal (EC-PC) for the efficient detection of metal ions in blood. By meticulously controlling the crystallization and annealing conditions in the co-crystallization strategy, the crystal growth processes were optimized to obtain doped Eu³⁺ complex-co-protein crystalline (EC-PC) structures. Thus, through co-crystallization of hen egg white lysozyme (HEWL) as a model protein and Eu³⁺ complex as fluorescent center, we successfully prepared Eu³⁺ complex-doped-HEWL co-crystals (EC-HC) with excellent fluorescent properties. Further treatment with 4% glutaraldehyde cross-linking enhanced the structural stability of the co-crystals. Moreover, the characteristic of sensitive, selective quenching of EC-PC fluorescence by biologically relevant cations, such as Cu²⁺, Zn²⁺, Mg²⁺, Ca²⁺ and Fe³⁺ ions, set up a smart sensing system in blood. For example, the fluorescence intensity of the crystals at 610 nm, as measured by a UV–visible spectrophotometer, decreases dose-dependently with the concentration of copper ions, thereby validating the sensor’s high sensitivity to copper ion detection. Significantly, we also found that this hybrid protein-based sensor did not induce hemolysis, at various volume concentrations, confirming good anticoagulation in blood. This research not only provides a new perspective on the application of Eu³⁺ complex-doped protein crystals in the field of biosensing but also offers a new strategy for the detection of biologically relevant cations in blood. Future work will focus on further optimizing the sensor’s performance and exploring its potential applications in clinical sample analysis. Full article

Rare-earth elements (REEs), which include the entire lanthanide series together with scandium and yttrium, have unique electronic configurations and coordination chemical properties that provide them with special magnetic, optical, and redox abilities. Generally used for diagnostic imaging and theranostic applications, increasing evidence emphasizes their potential as direct anticancer agents. This review aims to present a thorough investigation of the studies published in the last ten years that focus on the intrinsic anticancer properties of REE-based molecular complexes and nanostructures, without discussing their recognized imaging functions. Rare-earth compounds exhibit selective cytotoxicity against malignant cells via mechanisms that mainly include modulations in the generation of reactive oxygen species, mitochondrial dysfunctions, interaction with DNA molecules, apoptosis, and ferroptosis induction, as well as radiosensitization. Molecular complexes that are based on the trivalent coordination chemistry of REEs enable them to target biomolecules like DNA and serum albumin. Nanostructured systems, on the other hand, render tumors more responsive to treatment by improving the cellular uptake, enabling surface functionalization, and controlling ROS generation. Terbium, thulium, yttrium, scandium, ytterbium, cerium, erbium, dysprosium, and europium show different levels of anticancer activity in both in vitro and in vivo cancer models. They often exert more toxicity in tumor cells than in normal tissues, thus exhibiting selective anticancer effects. The findings collectively underscore the therapeutic potential of REE-based compounds as novel metal-based anticancer agents and advocate for additional mechanistic and translational research to enhance their clinical applicability. Full article

Osmium is a third-peak neutron-capture element predominantly produced by the rapid (r-) process, and it is a valuable tracer of early Galactic chemical enrichment. However, osmium abundance measurements in Galactic stars remain limited due to observational challenges. We present new osmium abundances for 23 stars at intermediate metallicities ($-2.5\le$ [Fe/H] $\le -1.0$) within the framework of the MINCE (Measuring at Intermediate Metallicity Neutron-Capture Elements) project. A standard abundance analysis was carried out using one-dimensional LTE model atmospheres and the optical Os I line at 479 nm observed in high-quality UVES spectra. The derived [Os/Fe] ratio exhibits an anticorrelation with [Fe/H], supporting efficient r-process enrichment during the early phases of the Milky Way’s evolution. We also investigated Os abundances across different Galactic components, finding that halo and Gaia–Sausage–Enceladus stars are more Os-rich than thick-disk stars. A comparison between Os and europium abundances supports a common r-process origin for these elements at intermediate metallicities. Full article

The Jiaodong Peninsula constitutes a world-class gold province in eastern China, containing more than 5000 t of identified gold resources. The Jiaojia gold deposit is one of the largest deposits within this gold province, and mineralization is primarily distributed along the northern segment of the Jiaojia Fault. The structural characteristics and mineralization processes of the northern segment have been extensively documented. In contrast, the ore-forming mechanisms of the southern Jiaojia Fault remain poorly constrained, hindering further exploration targeting. We chose several gold deposits and one drill core along the Jiaojia Fault, then present whole-rock major and trace elements data to evaluate magmatic affinities and their ore-forming potential. The results show that the lithological differences in plutonic and stratigraphic units suggest that variations in petrogenesis may have exerted a fundamental control on mineralization styles. Almost all samples are characterized by enrichment in light rare earth elements, relative enrichment in Europium, and pronounced depletion in heavy rare earth elements. Alteration characteristics indicate the northern segment is dominated by advanced argillic alteration, whereas phyllic alteration is more prevalent in the southern segment. The rare earth elements discrimination plot clearly suggests differentiation from the northern and southern fault segments. Consequently, we propose that the northern segment records synorogenic arc magmatism, while the southern segment experienced both synorogenic and a subsequent intraplate extensional transitional stage. Full article

The Ordovician system in the Shunbei area of the Tarim Basin hosts typical ultra-deep, fault-controlled fracture–vuggy hydrocarbon reservoirs. Compared with the surrounding Tabei and Tazhong areas, the genetic types of Ordovician formation water in Shunbei are more complex, and the relationships and spatial distribution of oil, gas, and water exhibit strong heterogeneity and pronounced fault control. This study systematically collected formation water geochemical and pressure data to clarify the geochemical characteristics and origin of Ordovician formation water in the Shunbei area and to investigate the indicative relationships between ion concentrations and ionic ratios of formation water and reservoir dolomitization, hydrocarbon migration, and accumulation. Research shows that, in contrast to the Tabei and Tazhong areas, the Ordovician formation water in Shunbei is predominantly of the calcium chloride (CaCl₂) type, with enrichment in Ca²⁺ and depletion in Mg²⁺, which may be related to euhedral dolomitization. In fault-controlled fracture–vuggy reservoirs, a high desulfurization coefficient—contrary to its interpretation in conventional reservoirs—corresponds to favorable zones for hydrocarbon accumulation. The rare earth element (REE) composition of the formation water is characterized by heavy REE enrichment, a distinct negative cerium (Ce) anomaly, and a positive europium (Eu) anomaly. Combined with hydrogen–oxygen and strontium isotopic data, these features indicate that the Ordovician formation water in Shunbei represents original depositional paleoseawater that has undergone cross-formational flow and concentration. The water bodies are divided into two distinct formation water systems bounded by the Shunbei No. 5 fault zone. Favorable zones for hydrocarbon enrichment are controlled by source rock distribution, and hydrocarbons migrate together with formation water along strike-slip faults within the Shunbei area, showing a northwest-to-southeast trend. The region between the middle segments of the Shunbei No. 4 and No. 8 fault zones is identified as a favorable area for hydrocarbon accumulation. Full article