Search Results (196)

Objective: Rare-earth elements are extensively employed across diverse industrial sectors, increasingly raising concerns about their potential health hazards in both occupational and environmental contexts. Samarium oxide (Sm₂O₃), a routinely processed rare-earth product, reproducibly precipitates pulmonary fibrosis in experimental models, yet the molecular circuitry that transduces its fibrogenic signal remains almost entirely unmapped. This study aims to elucidate the role of miR-214-3p in Sm₂O₃-induced pulmonary fibrosis and to investigate its regulatory mechanism at the molecular level. Methods: A murine model of pulmonary fibrosis was established via intratracheal instillation of Sm₂O₃, and histopathological changes were assessed using hematoxylin and eosin (H&E) and Masson’s trichrome staining. RNA sequencing was performed on lung tissues to identify differentially expressed mRNAs. Leveraging our previously generated miRNA landscape of Sm₂O₃-exposed lungs, we subjected the dataset to Gene Ontology and KEGG enrichment analyses, which convergently identified miR-214-3p as the top-ranking candidate regulator of the fibrogenic MAPK axis. The direct targeting of MAP2K3 by miR-214-3p was validated using a dual-luciferase reporter assay. Expression levels of fibrotic markers (α-SMA, Collagen I) and key components of the MAPK signaling pathway (MAP2K3, p-MAPK14, MST1) were quantified in both in vivo and in vitro models using qRT-PCR and Western blotting. Gain- and loss-of-function studies, complemented by rescue assays, were performed in human embryonic lung fibroblasts (HELFs) via transient transfection of miR-214-3p mimics, inhibitors, or MAP2K3-overexpression plasmids. Cell proliferation was evaluated using the EdU assay, and TGF-β1 secretion was measured by ELISA. Results: Sm₂O₃ exposure induced significant pulmonary fibrosis in mice, accompanied by marked downregulation of miR-214-3p and upregulation of MAP2K3 in lung tissues. Overexpression of miR-214-3p or silencing of MAP2K3 effectively suppressed Sm₂O₃-induced fibroblast activation, including reduced cell proliferation, decreased expression of α-SMA and Collagen I, and inhibition of p38 MAPK phosphorylation. Notably, ectopic overexpression of MAP2K3 reversed the protective effects conferred by miR-214-3p, confirming a functional rescue. Conclusions: miR-214-3p directly silences MAP2K3, thereby blunting p38 MAPK-driven fibrogenesis after Sm₂O₃ exposure. Our data unveil a miR-214-3p–MAP2K3–p38 MAPK axis that constitutes a readily druggable target for rare-earth-element-induced pulmonary fibrosis. Full article

Recently, the demand for electric motors that can achieve high performance while ensuring stable magnet supply has continued to increase across various industrial sectors. Although rare-earth permanent magnets, such as neodymium and samarium cobalt, enable superior electromagnetic performance, their high cost and supply instability have motivated growing interest in motors employing non-rare-earth permanent magnets, such as ferrite magnets. Due to the relatively low remanent flux density and coercivity of non-rare-earth magnets, spoke-type rotor structures are commonly adopted to enhance flux concentration. However, spoke-type configurations inherently suffer from axial leakage flux, in which a portion of the magnetic flux generated by the permanent magnets fails to link with the stator and instead leaks along the axial direction. This axial leakage flux reduces the effective air-gap flux density, leading to a degradation of back electromotive force (back-EMF) and overall motor performance. In this study, a double-spoke-type motor employing asymmetric permanent magnet geometry is investigated. Finite element analysis (FEA) is performed to identify an effective rotor structure that reduces axial leakage flux without increasing magnet usage, demonstrating the feasibility of performance improvement in non-rare-earth permanent magnet motors. Full article

Biofilm-associated infections remain a major barrier to wound healing, implant integration, and chronic infection management. Rare-earth oxides (REOs) have emerged as promising antibiofilm materials, though their mechanisms, limitations, and translational potential are still being defined. Cerium oxide (CeO₂) serves as the benchmark due to its redox adaptability, oxygen-vacancy-driven catalytic activity, and host compatibility. In contrast, non-ceria REOs show antibiofilm effects under more restricted conditions, often requiring surface functionalization, composite architectures, or hybrid organic–inorganic interfaces—such as polyphenol coatings or hydroxyapatite-based composites—to achieve comparable activity. Across systems, biofilm control arises not from bactericidal potency but from matrix-level mechanisms including extracellular polymeric substance (EPS) destabilization, extracellular DNA (eDNA) sequestration, redox modulation, and quorum-sensing interference. Preclinical and near-clinical evidence, particularly in chronic wound models, supports the translational relevance of these mechanisms, though the evidence base remains preliminary. This review synthesizes mechanistic data across cerium-, samarium-, lanthanum-, and strontium-based systems to establish a unified framework for REO-mediated biofilm disruption. REOs are positioned as biofilm-modulating platforms that complement antibiotics, enhance healing, and improve outcomes. Design rules emphasize controlled redox activity, targeted coordination chemistry, functional surface engineering, and host-compatible performance, alongside regulatory and manufacturing guidance for future development. Full article

The increasing adoption of digital light processing (DLP) three-dimensional (3D) printing in prosthodontics has enabled the rapid fabrication of denture bases with improved dimensional accuracy and reproducibility. However, the mechanical performance and surface characteristics of 3D-printed denture base resins remain inferior to those of conventional heat-polymerized polymethyl methacrylate (PMMA), limiting their long-term clinical reliability. This study aimed to investigate the effect of incorporating zinc oxide (ZnO) and samarium oxide (Sm₂O₃) nanoparticles, individually and as hybrid nanofiller systems, on the mechanical and wettability properties of a DLP 3D-printed denture base resin. ZnO and Sm₂O₃ nanoparticles were incorporated into a photopolymerizable denture base resin at concentrations of 1 and 2 wt.%, producing seven experimental formulations, including a control group. A total of 280 specimens were fabricated using a DLP 3D printer and subjected to standardized post-processing. Nanoparticle dispersion and morphology were examined using field-emission scanning electron microscopy (FE-SEM), while Fourier-transform infrared spectroscopy (FTIR) was employed to assess possible chemical interactions between the nanofillers and the polymer matrix. Mechanical performance was evaluated through impact strength, transverse strength, and flexural strength tests, and surface wettability was assessed using static water contact angle measurements. Statistical analysis was conducted using one-way ANOVA followed by Tukey’s post hoc test (α = 0.05). The results demonstrated that all nanoparticle-reinforced groups exhibited significantly enhanced mechanical properties compared with the unmodified control resin. The incorporation of 1 wt.% nanofillers yielded the most pronounced improvements, with the 1 wt.% ZnO group achieving the highest transverse strength and the 1 wt.% ZnO–Sm₂O₃ hybrid group exhibiting the maximum flexural strength. Increasing the nanofiller concentration to 2 wt.% resulted in partial reductions in impact and flexural strength, which were attributed to nanoparticle agglomeration and increased light scattering during photopolymerization. FTIR analysis revealed no evidence of chemical bonding between the resin matrix and the nanofillers, indicating that the observed enhancements were primarily governed by physical reinforcement mechanisms. Wettability analysis showed that Sm₂O₃-containing formulations significantly reduced the water contact angle, indicating increased surface hydrophilicity, whereas ZnO incorporation produced more hydrophobic surfaces. Within the limitations of this in vitro study, the findings suggest that low-concentration incorporation of ZnO and Sm₂O₃ nanoparticles represents an effective strategy to enhance the mechanical integrity and tailor the surface properties of DLP 3D-printed denture base resins. These results suggest potential clinical relevance of nanoparticle-reinforced printed denture bases, emphasizing the importance of optimized filler loading to avoid agglomeration-induced performance degradation. Full article

Sm₂TM₁₇ sintered magnets, (where TM = Co, Fe, Cu, Zr), are typically utilised in high temperature magnetic applications due to their magnetic properties being very stable at 200–350 °C. Sm and Co are critical materials and need to be recycled to reduce reliance on virgin material supply chains. This work explored HD processing of Sm₂TM₁₇ sintered magnet production scrap as a potential recycling technique. Sintered magnet scrap was initially analysed compositionally, microstructurally and magnetically to determine issues with magnet quality. Scrap material was then HD processed at 18 bar and 2 bar at temperatures between 25–300 °C. The resultant material was characterised in terms of hydrogen content, particle size, degassing behaviour and unit cell expansion. Production scrap magnets exhibited irregular demagnetisation traces with poor domain wall pinning behaviour. Non-magnetic ZrC inclusions likely prevented cell structure formation locally and hence were poor domain wall pinning sites. Scrap material processed at 18 bar and 2 bar required temperatures of 100 °C to allow for the greatest extent of HD reaction, reaching 0.299 Wt.% and 0.323 Wt.% hydrogen respectively. The HD behaviour of production scrap material was comparable to commercial grade magnets. Therefore, HD is a potentially viable technique for recycling Sm₂TM₁₇ sintered magnet production scrap. Full article

Carbon dioxide (CO₂) and methane (CH₄) are major greenhouse gases, and their increasing emissions contribute significantly to global warming. Dry reforming of methane (DRM) offers a promising route to mitigate these emissions by simultaneously utilizing both CO₂ and CH₄ and converting them into syngas, a valuable intermediate for producing fuels and chemicals. Nickel-based catalysts are widely used in DRM due to their high activity and cost-effectiveness. However, their performance depends strongly on metal loading and support properties. This study aims to investigate the effect of different NiO loadings (40, 50, and 60 wt%) on the structural and morphological characteristics of NiO-YSZ and NiO-SDC catalysts synthesized via the impregnation method. In this method, yttria-stabilized zirconia (YSZ) and samarium-doped ceria (SDC) powders were dispersed into a nickel precursor solution to form supported catalysts, which were then characterized to evaluate their structural integrity, crystallinity, and surface morphology. The results showed that higher NiO loadings generally improved the structural and morphological features, with NiO-SDC demonstrating better characteristics than NiO-YSZ. These findings provide essential insights that will guide future work on fabricating membranes using these catalysts for the CO₂-CH₄ dry reforming process. Full article

Rare-earth oxide (REO) nanoparticles (NPs)—such as cerium (CeO₂), samarium (Sm₂O₃), neodymium (Nd₂O₃), terbium (Tb₄O₇), and praseodymium (Pr₂O₃)—have demonstrated strong antimicrobial activity against multidrug-resistant bacteria. Their effectiveness is attributed to unique physicochemical properties, including oxygen vacancies and redox cycling, which facilitate the generation of reactive oxygen species (ROS) that damage microbial membranes and biomolecules. Additionally, electrostatic interactions with microbial surfaces and sustained ion release contribute to membrane disruption and long-term antimicrobial effects. REOs also inhibit bacterial enzymes, DNA, and protein synthesis, providing broad-spectrum activity against Gram-positive, Gram-negative, and fungal pathogens. However, dose-dependent cytotoxicity to mammalian cells—primarily due to excessive ROS generation—and nanoparticle aggregation in biological media remain challenges. Surface functionalization with polymers, peptides, or metal dopants (e.g., Ag, Zn, and Cu) can mitigate cytotoxicity and enhance selectivity. Scalable and sustainable synthesis remains a challenge due to high synthesis costs and scalability issues in industrial production. Green and biogenic routes using plant or microbial extracts can produce REOs at lower cost and with improved safety. Advanced continuous flow and microwave-assisted synthesis offer improved particle uniformity and production yields. Biomedical applications include antimicrobial coatings, wound dressings, and hybrid nanozyme systems for oxidative disinfection. However, comprehensive and intensive toxicological evaluations, along with regulatory frameworks, are required before clinical deployment. Full article

Due to the reinforcement of energy efficiency regulations and the pursuit of sustainable development goals, the demand for high-efficiency electric motors has been steadily increasing. Rare-earth permanent magnets such as neodymium (Nd) and samarium (Sm) provide high power density, but their high cost and unstable supply chains have led to growing interest in ferrite-based motors. Ferrite magnets offer excellent cost-effectiveness; however, their relatively low remanent flux density and coercivity result in reduced motor performance. To compensate for these limitations, a spoke-type flux-concentrating structure is commonly employed to enhance the air-gap flux density. Nevertheless, in spoke-type motors, the magnets are deeply embedded within the rotor, making it difficult to achieve a sufficient magnetization rate during post-assembly magnetization. In this study, an optimized magnetizing yoke is proposed to achieve a post-assembly magnetization rate of over 99% while suppressing the irreversible demagnetization of untargeted magnets. Finite element analysis (FEA) results for a 10-pole ferrite rotor confirm that the proposed structure demonstrates excellent magnetization performance and effectively mitigates irreversible demagnetization. Full article

There is an urgent need to evaluate the toxicity of xenobiotics and environmental mixtures for preventing loss in water quality for the sustainability of aquatic ecosystems. A simple prebiotic chemical pathway based on malate formation from pyruvate (pyr) and glyoxalate (glyox) is proposed as a quick and cheap screening tool for toxicity assessment. The assay is based on the pyr and glyox (aldol) condensation reactions, leading to biologically relevant precursors such as oxaloacetate and malate. Incubation of pyr and glyox at 40–70 °C in the presence of reduced iron Fe(II) led to malate formation following the first 3 h of incubation. The addition of various xenobiotics/contaminants (silver, copper, zinc, cerium IV, samarium III, dibutylphthalate, 1,3-diphenylguanidine, carbon-walled nanotube, nanoFe₂O₃ and polystyrene nanoparticles) led to inhibitions in malate synthesis at various degrees. Based on the concentration inhibiting malate concentrations by 20% (IC20), the following potencies were observed: silver < copper ~ 1.3-diphenylguanidine ~ carbon-walled nanotube < zinc ~ samarium < dibutylphthalate ~ samarium < Ce(IV) < nFeO₃ < polystyrene nanoplastics. The IC20 values were also significantly correlated with the reported trout acute lethality data, suggesting its potential as an alternative toxicity test. The pyr-glyox pathway was also tested on surface water extracts (C18), identifying the most contaminated sites from large cities and municipal wastewater effluents dispersion plume. The inhibition potencies of the selected test compounds revealed that not only pro-oxidants but also chemicals hindering enolate formation, nucleophilic attack of carbonyls and dehydration involved in aldol-condensation reactions were associated with toxicity. The pyr-glyox pathway is based on prebiotic chemical reactions during the emergence of life and represents a unique tool for identifying toxic compounds individually and in complex mixtures. Full article

In this work, Sm³⁺-activated lead phosphate glass has been studied using spectroscopic methods. Based on absorption spectrum measurements, the oscillator strengths for Sm³⁺ ions were determined and compared to those calculated from the Judd–Ofelt theory. This procedure was applied to evaluate some radiative parameters (radiative transition rates, emission branching ratios, radiative lifetime) of Sm³⁺ ions in lead phosphate glass. Further luminescent studies indicate that lead phosphate glass doped with Sm³⁺ emits intense reddish-orange light due to ⁴G_5/2 ⟶ ⁶H_7/2 transition, for which several important spectroscopic parameters like emission linewidth and lifetime, quantum efficiency, peak stimulated emission cross-section, and figure of merit for laser gain were determined. The factors for Sm³⁺ ions in lead phosphate glass are as follows: η = 53%, FWHM = 10.5 nm, τ_exp = 1.925 ms, σ_em = 7.6 × 10⁻²² cm², σ_em × τ_exp = 14.6 × 10⁻²⁵ cm²s. The experimental and theoretical results suggest that samarium-doped lead phosphate glass can be successfully used as a reddish-orange-emitting component in photonic devices. Full article

Samarium, a rare earth element, is crucial for advanced technological applications, particularly due to the exceptional magnetic properties of Sm_xCo_y intermetallics, discovered over 50 years ago. However, its growing significance and demand have highlighted concerns about scarce, commercially viable natural sources and the complex separation processes needed to isolate it from other lanthanides. In this context, electrodeposition has emerged as a versatile method for both synthesizing samarium materials and recovering the element. A major obstacle in applying electrolysis lies in the complex electrochemical behavior of samarium species, stemming from their highly negative electrochemical potential. While this limits the use of aqueous solutions, it also opens up possibilities for alternative solvents, such as molecular liquids, ionic liquids, deep eutectic solvents, and molten salts. The electrochemical properties of samarium have prompted exploration into electrodeposition techniques for material synthesis and recycling. This review discusses various aqueous and non-aqueous electrolyte compositions, different electrolysis modes, and the role of cathode substrates. It also shows the potential of electrolysis in the fabrication of various cathode products (metal, alloys/intermetallics, inorganic compounds), highlighting both challenges and opportunities in its practical implementation. Full article

Sm₂TM₁₇ sintered magnets (TM = Co, Fe, Cu, Zr) are utilised in high-temperature rotor applications due to their stable magnetic properties at elevated temperatures of 200–350 °C. However, Sm and Co are critical elements, and the reliance on virgin material supply chains must be reduced. Hydrogen decrepitation (HD) could facilitate magnet-to-magnet recycling of scrap material, but the milling characteristics of the powders generated by HD requires investigation. Sm₂TM₁₇ sintered magnets were exposed to 18 bar and 2 bar hydrogen pressure at 100 °C for 72 h and then knife-milled, roller ball-milled, and planetary ball-milled for varying milling times utilising a variety of surfactants. The particle size and morphology of the powders were investigated, and sintered magnets manufactured from chosen powders were characterised in terms of composition, density, microstructure, and magnetic properties. Knife milling for two minutes showed major particle size reductions of 70 and 82% in D50 for 18 bar and 2 bar samples respectively. Roller ball milling trials showed that a cyclohexane and oleic acid mixture was the most effective at reducing particle size, reducing D10, 50, and 90 by 92, 91, and 80% respectively. Knife milling HD powder for two minutes and then planetary ball milling this powder in a cyclohexane and 1 wt.% oleic acid mixture generated a particle size distribution of 1.3–6.8 µm. This powder formed a sintered compact with a density 0.08 g/cm³ lower than the as-received material. Sm losses due to oxidation and sublimation in addition to carbon impurities from surfactant usage caused the precipitation of an α-Fe/Co phase and formed ZrC phases respectively. Sm-hydride additions of 2–3 wt.% mitigated the formation of the α-Fe/Co phase, but ZrC phases remained and likely prevented cell structure formation and inhibited domain wall pinning in recycled magnets. Full article

Understanding the way samarium–cobalt alloys solidify at varying cooling rates and the regularities in alloying element distribution is crucial for optimizing subsequent homogenization and annealing processes, leading to an enhancement in the overall quality of the product. The study investigates the effects of rapid water-cooled copper mold (600 °C/min), medium-speed copper mold (100 °C/min), and slow furnace cooling (10 °C/min) on the microstructural evolution, element distribution, and phase transformation of samarium–cobalt (Sm-Co) alloys. The results of the research show that the phase transition temperatures obtained via differential scanning calorimetry (DSC) closely matched those observed in situ by high-temperature laser scanning confocal microscopy (HT-LSCM). Higher cooling rates resulted in notable dendritic refinement and reduced precipitate size. Elemental analysis revealed that Co and Fe exhibited negative segregation, whereas Sm, Cu, and Zr showed positive segregation, with segregation intensity increasing alongside the cooling rate. The principal phases identified included Cu-rich and Zr-rich constituents, the matrix phase, and a gray phase morphologically distinct from the matrix. These correspond to the (Sm, Co, Fe, Cu, Zr)₅ phase, (Sm, Zr)(Co, Fe, Cu)₃ phase, Sm₂(Co, Fe, Cu, Zr)₁₇ phase, and Sm(Co, Fe, Cu, Zr)₇ phase. The phase constitution remained consistent across different cooling rates. Full article

This work shows that inverse Judd–Ofelt (JO) analysis of relative absorption spectra, anchored by a single lifetime, provides JO parameters and radiative rates without absolute calibration. The method is applied to Er³⁺, Dy³⁺, and Sm³⁺ in a compositionally identical oxyfluoride glass. Three well-resolved ground-state 4f–4f absorption bands were selected. After baseline removal and wavenumber-domain integration, their normalized strengths S_rel,k (k = 1, 2, 3; k∈S) define a 3 × 3 system solved by non-negative least squares to obtain the anchor-independent ordering (Ω₂:Ω₄:Ω₆). Absolute scaling uses a single lifetime anchor. We report lifetime-scaled Ω_t and A_rad, and the normalized fractions p_k within the selected triplets; as imposed by the method, the anchor-independent ordering (Ω₂:Ω₄:Ω₆) is analyzed, while absolute A_rad and Ω_t scale with τ_ref. The extracted parameters fall within the expected ranges for oxyfluoride hosts and reveal clear ion-specific trends: Ω₂ follows Dy³⁺ > Er³⁺ > Sm³⁺ (site asymmetry/hypersensitive response), while the ordering Ω₄ > Ω₆ holds across all ions (oxide-rich networks). Er³⁺ exhibits the largest Ω₄ and the smallest Ω₆, indicative of pronounced medium-range “rigidity” with suppressed long-range polarizability; Sm³⁺ shows the lowest Ω₂ (more symmetric/less covalent coordination); and Dy³⁺ the highest Ω₂ (strong hypersensitive behavior). Uncertainty was quantified by Monte Carlo resampling of the preprocessing steps, yielding compact 95% confidence intervals; the resulting JO-parameter trends (Ω₂, Ω₄, Ω₆) and normalized f_k fractions reproduce the characteristic spectroscopic behavior known for each ion. This method enables quantitative JO outputs from uncalibrated spectra, allowing direct spectroscopic comparisons and quick screening when only relative absorption data are available. Full article

High-performance but expensive neodymium-iron-boron (Nd-Fe-B) magnets are widely used in automotive and electrical applications. Prospective candidates for rare-earth-free magnets include Fe-based magnets such as L1₀-FeNi and α″-Fe₁₆N₂ phase. However, these rare-earth-free magnets cannot replace Nd-Fe-B magnets due to their lower coercivity. Thus, the development of Sm-based magnets, using the relatively abundant rare-earth element Sm, has become a focus of attention. A promising, cheaper alternative with excellent magnetic properties is the Samarium-iron-nitride (Sm-Fe-N) magnet. This paper describes the production and magnetic properties of Sm-Fe-N powders with Th₂Zn₁₇ and TbCu₇ phases. The production process and magnetic properties of Sm-Fe-N bonded magnets prepared from the powders are also described. Current approaches for producing Sm-Fe-N sintered magnets are included. Full article