Search Results (73,583)

Environmental contamination with potentially toxic elements is a growing concern for ecosystem quality and food safety. This study evaluated the relationships between environmental conditions, anthropogenic activities, and the elemental composition of Prunus spinosa fruits collected from western and central Romania along a pollution gradient. Eighty samples from ten sites representing non-polluted, agricultural, traffic-exposed, and mining-affected areas were analyzed by ICP-MS after microwave digestion. Fruits from impacted areas showed compositional differences, including lower concentrations of some essential macroelements and higher levels of several trace elements potentially associated with anthropogenic pressure. Increased sodium, aluminum, and silicon contents were consistent with environmental stress and enhanced environmental exposure and possible soil-derived particulate influence, while boron and molybdenum declined with pollution intensity. Elemental patterns were mainly associated with local environmental conditions and appeared consistent with site-specific environmental influences. Food safety assessment indicated generally low to moderate risk depending on sampling origin. Overall, Prunus spinosa fruits showed potential as a bioindicator of environmental quality and a useful tool for monitoring anthropogenic contamination. Full article

Bilirubin is an important biomarker, where a small unbound fraction dissociated from albumin can cross the blood–brain barrier and induce neurotoxicity, such as kernicterus, at low nanomolar levels. Accurate detection of this low-level fraction remains challenging. Surface-enhanced Raman spectroscopy (SERS) enables label-free molecular detection; however, variations in the local refractive index (RI) at plasmonic hotspots can detune the resonance from the excitation wavelength, leading to signal fluctuations and limited quantitative reliability. Here, we present a multi-resonant nanolaminate SERS substrate designed to achieve RI-insensitive and robust signal enhancement. The vertically stacked metal–insulator–metal architecture provides broadband spectral overlap with both excitation and Raman scattering under dielectric loading, maintaining consistent enhancement across varying RI conditions. We demonstrate label-free bilirubin detection with a highly linear response over 10⁻⁹ to 10⁻⁴ M, achieving an R² value of 0.99. Compared with previously reported bilirubin SERS substrates relying mainly on single-resonant plasmonic enhancement, this RI-insensitive design offers improved quantitative reliability under dielectric environmental changes. These results highlight the importance of RI-insensitive SERS design for reliable quantification and provide a general strategy for robust SERS-based biosensing. Full article

The DC resistivity method is extensively employed in metal mineral exploration, hydrogeology, and engineering geology owing to its cost-effectiveness and high precision. High-precision 3D forward modeling of DC resistivity is crucial for the efficient inversion of resistivity data to delineate the true subsurface resistivity distribution. This paper presents a three-dimensional DC resistivity forward modeling algorithm based on a high-order finite element method (FEM). Initially, the model domain is discretized using an unstructured mesh composed of arbitrary tetrahedral elements. Subsequently, isoparametric element transformation techniques are utilized to construct high-order nodal basis functions. Furthermore, a novel absorption boundary condition, leveraging real number and coordinate stretching techniques, is implemented; this condition is notably straightforward to implement. The resulting finite element system of equations is then solved using the parallel direct solver MUMPS. To validate the accuracy and efficacy of the proposed algorithm, forward calculations are performed on several typical geoelectric models. The results demonstrate that increasing the element order enhances the computational accuracy of the finite element numerical solution. Moreover, the proposed absorption boundary condition outperforms conventional Dirichlet boundary conditions without incurring additional computational cost. Full article

Polysilicate-ferric-aluminum-zirconium (PSFAZ) was prepared using co-polymerization for the treatment of phosphorus wastewater. The preparation conditions of PSFAZ were optimized through a series of single-factor experiments, including Zr/Fe molar ratio, pH, sedimentation time, and dosage. The results demonstrated that PSFAZ exhibited an excellent phosphorus removal performance with 99.3% removal efficiency under the conditions of Zr/Fe ratio of 0.6/1, pH of 6, dosage of 25 mL/L and sedimentation time of 2 h. In real wastewater treatment, PSFAZ exhibited an exceptional phosphorus removal efficiency of 99.6%, accompanied by negligible metal leaching. The characterization results reveal that charge neutralization, ligand exchange, bridging effect and complexation reactions between metal ions and phosphorus play a dominant role in phosphorus removal. This study provides valuable insights into the practical application of novel inorganic composite flocculants for phosphorus wastewater treatment and reuse. Full article

Histone deacetylase inhibitors (HDACi) are an emerging class of epigenetic anticancer drugs that exert their activity through coordination to the catalytic Zn²⁺ ion within the active site of histone deacetylases (HDACs). Due to the limited isoform-selectivity of hydroxamic acid-based inhibitors, benzamide-based HDACi (BBHDACi) have been developed as subtype-selective alternatives. Clinically relevant representatives include Chidamide, Entinostat, Mocetinostat, Zabadinostat, and Tacedinaline. Although these compounds share a conserved o-aminoanilide zinc-binding group (ZBG), they differ in linker and cap region structure, raising questions regarding their intrinsic Zn²⁺ affinity and coordination behavior. Herein, density functional theory (DFT) calculations were performed at the B3LYP/6-311++g(d,p) level of theory combined with the PCM solvation in methanol (ε = 33) and water (ε = 78). Geometry optimization confirmed that the trans (E) isomer of Chidamide is thermodynamically preferred. Coordination studies showed that the remaining BBHDACi adopt stable geometries, with the o-aminoanilide group preferentially forming tetracoordinated complexes that are more stable than hexacoordinated ones in polar media. Interestingly, calculated substitution free energies differed by less than ± 2 kcal.mol⁻¹, indicating nearly identical intrinsic Zn²⁺ affinities across the series. These results suggest that the ZBG contributes similarly to metal coordination across all BBHDACi, whereas the overall binding strength is mainly governed by interactions of the linker and cap regions rather than by the conserved zinc-binding group itself. Full article

Open environmental monitoring datasets are increasingly used in water-pollution research because they provide broad spatial and temporal coverage and support reproducible large-scale analyses. However, their interpretation may depend strongly on preprocessing decisions, particularly when many observations are reported below the limit of quantification (LOQ). This study evaluated the sensitivity of inferred heavy-metal pollution patterns to preprocessing choices in open European surface-water monitoring data. Publicly available Waterbase records for cadmium, lead, and nickel were restricted to rivers and lakes. After removing missing values and a subset of implausible extreme observations above 1000 µg/L, the main analytical dataset contained 1,475,409 observations. Below-LOQ records accounted for 66.6% of cadmium, 57.3% of lead, and 36.1% of nickel observations. A separate censoring-analysis dataset (1,259,636 observations) was used to compare three scenarios: removal of below-LOQ observations, substitution with half the LOQ, and substitution with the full LOQ. Censoring treatment substantially affected concentration summaries, with the strongest sensitivity observed for cadmium, followed by lead, whereas nickel was comparatively more stable. The effect persisted after station-year aggregation and also altered hotspot identification. These findings show that although open monitoring data are valuable for pollution research, robust interpretation requires explicit and transparent reporting of preprocessing decisions. Full article

In this work a study about the behavior of nanomaterial-based innovative transparent electrodes is presented, with a special focus on graphene, for space photovoltaic applications, in particular their transparency and the efficiency of the final device. The efficiency of a solar cell is characterized by referring to Power Conversion Efficiency and External/Internal Quantum Efficiency. Starting from the literature results, it is possible to observe that solar cells realized by innovative nanomaterial-based transparent electrodes show promising results in terms of efficiency in the Earth environment. It is known that the space environment is characterized by extreme conditions including high-energy radiation, strong temperature variations and high vacuum, which can damage materials and, consequentially, influence their performances. Among all the properties like transmittance and sheet resistance, which are the main requirements for a good transparent electrode, could change their value and, therefore, influence the efficiency of the solar cell adopting this kind of electrode. In this paper, a theoretical analysis on the effects of high-energy radiation on the transmittance of graphene layers is given, leading to the observation that in the UV frequency range, it shows a sharp fall. Moreover, the effect of temperature varying is studied by an theoretical analysis on the resistivity of the twisted graphene bilayer. It is possible to observe that, in this configuration, the system moves from a superconductor to a metal, according to temperature and twist angle. This represents a starting point to have good efficiency of solar devices in a space environment by keeping high the transparency of their electrodes. Full article

Lentinula edodes (L. edodes) is a significant edible and medicinal mushroom with essential nutrient elements for its growth, including Fe²⁺, K⁺, and Mn²⁺. However, the molecular mechanisms by which these metal ions regulate the mycelial growth of L. edodes have been poorly elucidated at the transcriptomic level. In this study, plate culture was performed using concentration gradients to screen for optimal concentrations. Based on the plate culture assay results, L. edodes strain 1303 was treated with 40 μg/mL Fe²⁺, 1200 μg/mL K⁺, and 50 μg/mL Mn²⁺, with a control group (CK) without additional metal ion supplementation. Three biological replicates were set for each treatment, and the mycelia were collected for transcriptome sequencing (RNA-seq). The results showed that Fe²⁺ at concentrations above 20 µg/mL significantly inhibited mycelial growth; K⁺ at 1200 µg/mL and Mn²⁺ at 50 µg/mL significantly promoted mycelial growth, with increases in mycelial growth radius on day 7 of 21.22% and 10.77%, respectively, compared with the control group (p < 0.05). Transcriptomic analysis revealed that Fe²⁺ was associated with impaired protein folding-related functions and suppressed material and energy metabolism, which may contribute to the inhibition of mycelial growth. Mycelial growth promotion by K⁺ was associated with enhanced detoxification and secondary metabolism, as well as suggested enrichment of mitochondrial function and the oxidative phosphorylation pathway. Mn²⁺ may contribute to mycelial growth via mechanisms related to DNA repair and recombination, cell cycle progression, and detoxification. This study elucidates the differential gene expression patterns and regulatory effects of the three exogenous metal ions on the mycelial growth of L. edodes at the transcriptomic level, offering a rationale basis for mineral nutrition optimization during the mycelial stage. However, these interpretations are based on transcriptomic data only and lack direct evidence from ion uptake, proteomic, or metabolomic validation. Future studies will focus on validating these results through multilevel omics and functional experiments. Full article

Gold-enriched silica-listvenite rock from the Kaymaz Gold Deposit (KGD) was investigated to determine the effect of regional tectonism and Eocene granite intrusion on gold mineralization. The questions “is granite a heat–fluid source or a lithologic barrier?” and “how does regional tectonism affect gold mineralization?” remain unclear. This study aims to clarify these questions via field studies, core sample observations, petrography, ore microscopy, scanning electron microscopy (SEM), XRD, and fluid inclusion analyses; these methods were applied to samples collected from four different sites within the KGD (1—Damdamca, 2—Karakaya, 3—Mermerlik, and 4—Kızılağıl). The highest-grade gold mineralization is present in the listvenite rock in the fault-controlled contact zone between serpentinite and granite, whereas granite hosts minor gold and silver enrichments near the contact. The orientations of contacts are compatible with the NW-SE-trending Eskişehir fault zone in Karakaya and the NE-SW-trending tear faults in Damdamca. Listvenite is silica-rich and has high iron oxy-hydroxide content, while granite is argilized and silicified along the contact with listvenite. Native gold grains were found between the quartz minerals of listvenite and granite. The adsorption of gold by goethite ± lepidocrocite has been observed in the listvenite samples of Mermerlik. Chromite, Ni-sulfide minerals, pyrite, arsenopyrite, galena, native silver, acanthite, iodargyrite, and goethite ± lepidocrocite are the other detected ore minerals. Secondary Cr-Fe-Mn oxide minerals were detected in a granite sample via SEM analyses. The data indicates that listvenitization-causing fluid partially remobilized these metals along with Au and reprecipitated them in the granite during mineralization. The homogenization temperatures (Th) (°C) of fluid inclusions vary between 116 and 393 °C, and the Th (°C) distribution indicates multi-phase mineralization. The Th (°C) values of listvenite and silicified granite are quite similar, which indicates that the same hydrothermal fluid circulated in both lithologies. The low salinity values (1.2–5.4%) indicate that the hydrothermal fluid was derived predominantly from meteoric water. The liquid–vapor ratios of inclusions and quartz textures indicate non-boiling conditions. Gold enrichment in the KGD developed in relation to the circulation of hydrothermal fluids along the faults. The KGD shows typical fluid inclusions, alteration properties, and mineral paragenesis of low-sulfidation-type epithermal deposits. Our study data indicates that meteoric water-rich hydrothermal fluid circulated along the fault zones, dissolved Au and other related elements from the serpentinite, and reprecipitated in the listvenite-altered granite. Granite acts as an impermeable barrier, leading to the circulation of hydrothermal fluids through the contact. Supergene activities affect the mineralization in both Mermerlik and Kızılağıl. No evidence indicating the magmatic origin of gold mineralization was observed. Full article

Elemental sulfur frequently coexists with organic polysulfides in environmental samples and laboratory sulfurization experiments, complicating the accurate analysis of sulfur speciation. Reliable methods for selective sulfur removal are therefore required to avoid analytical artifacts. In this study, we systematically evaluated commonly used chemical sulfur removal approaches, including treatment with metallic copper and silver and reaction with tetrabutylammonium sulfite, and compared them with a chromatographic separation method based on C18 reversed-phase silica gel column chromatography. Model organic polysulfides, dimethyl polysulfides, diallyl polysulfides, dibenzyl disulfide, and cyclic polysulfide lenthionine were used to assess method performance under controlled conditions. The results demonstrate that chemical treatments are non-selective and lead to substantial decomposition of organic polysulfides, particularly for longer-chain compounds. In contrast, C18 reversed-phase silica gel column chromatography enables efficient and selective removal of elemental sulfur while preserving the original composition of organic polysulfides, with recoveries in the range of ~90–107%. These findings indicate that commonly applied sulfur removal procedures may introduce significant biases in sulfur speciation analyses. The chromatographic approach presented here provides a reproducible and non-destructive alternative for sample preparation, improving the reliability of studying sulfur speciation and transformation in natural and laboratory systems. Full article

Surface-enhanced Raman scattering (SERS) offers exceptional sensitivity for trace contaminant detection; conventional noble-metal substrates suffer from high cost, signal irreproducibility, and poor chemical stability. While semiconductor alternatives are promising, their performance is fundamentally limited by sluggish interfacial charge-transfer kinetics under static band alignment. To overcome these limitations, we introduced a new strategy centred on a high carrier generation rate (HCGR). By integrating TiOPc, a material that exhibits strong Ti–O bond polarisation and a high HCGR, with atomically thin MoS₂, we constructed a hybrid platform that drives efficient charge transfer via HCGR-enabled kinetic pumping, surpassing traditional thermodynamic band engineering. This HCGR-driven efficient CT mechanism primarily amplifies SERS through enhanced chemical mechanisms (CM) with minor electromagnetic contributions, achieving an enhancement factor (EF) of 10⁷. The platform can detect methylene blue (MB) and rhodamine 6G (R6G) at concentrations as low as 10⁻¹⁴ M and 10⁻¹³ M, respectively, demonstrating excellent repeatability (RSD = 7.2%) and stability over 60 days. Additionally, efficient CT accelerated MB photodegradation under UV light, achieving complete decomposition within 80 min. The practical applicability of the platform is evidenced by detecting Hg²⁺ (LOD: 10⁻¹¹ M) and malachite green in tap/lake water (LODs: 10⁻¹² M/10⁻¹⁰ M). This work establishes HCGR-driven efficient CT as the next generation of semiconductor SERS platforms. It provides a scalable route toward low-cost, reusable sensors for real-time, in situ monitoring of industrial effluents and the dynamic pollutant degradation of pollutants in environmental monitoring. Full article

The performance of a Mayenite-supported nickel-based catalyst were investigated by using an in-house-designed, assembled and set-up chemical pilot plant, which was developed to provide experimental insights relevant to industrial scale up. In particular, the proposed heterogeneous catalytic system was structured in mm-sized spheres and tested in a large-scale experiment, in a fixed-bed reactor for the CO₂ methanation process, and the results were compared with the output achieved with a Ni/alumina catalyst produced by an analogous route as the benchmark. The obtained findings highlighted the effective potential of the Mayenite structure supporting metallic active sites in promoting CO₂ reduction under the selected operating conditions (450 °C, 4 bar), along with long-term stability and high CH₄ selectivity. Moreover, the available experimental equipment was optimized to achieve accurate estimations of amounts of reaction by-product , as confirmed by the optimal agreement with the mass balance retrieved from the measured gaseous outlet composition. Such an achievement, notable for a large-scale chemical plant, plays a capital role in terms of industrial applications due to the critical impact of residual carbon and water in establishing the viability of innovative catalyst systems for the CO₂ recycling process. Full article

Additive manufacturing (AM) has revolutionized industrial production. However, the repair of AM components remains a critical challenge due to their unique microstructural features. While repair approaches for conventionally manufactured alloys are well established, their direct transferability to AM parts remains largely unexplored due to the unique thermal history and anisotropic microstructure of additive components. This study investigates a novel repair and improvement strategy for Powder Bed Fusion–Laser Beam/Metal (PBF-LB/M)-fabricated AlSi10Mg components, combining Electrospark Deposition (ESD) for dimensional restoration with subsequent Ultrasonic Peening Treatment (UPT) for surface enhancement. Microstructure, porosity, surface roughness, hardness profiles, residual stresses, and corrosion behaviour were systematically characterized using SEM, optical microscopy, profilometry, Vickers microhardness testing, XRD, and electrochemical polarization tests. The results show that the ESD process is capable of producing coatings with excellent interfacial adhesion to the substrate, with an initial porosity of 3.6 ± 0.5%. The subsequent UPT induces a significant densification effect on the deposited material, reducing porosity by approximately 50% and increasing surface hardness by up to 48% in the upper region of the coating. Furthermore, XRD analysis reveals that UPT completely reverses the residual stress state from tensile (typical of the ESD process) to compressive in all measured directions, thereby improving the overall structural integrity. Ultimately, the combined ESD + UPT alters the electrochemical response of AlSi10Mg deposits, resulting in a nobler corrosion potential, albeit with a slightly higher corrosion current density. Full article

Electrochemical nitrogen reduction reaction (NRR) is a sustainable and environmentally friendly method for ammonia synthesis, offering a promising alternative to the Haber–Bosch method. Despite its considerable potential, NRR is still plagued by a scarcity of efficient catalysts. Metal–nitrogen–carbon (M–N–C) catalysts exhibit unique advantages in achieving excellent NRR performance. Theoretical calculations are crucial in understanding and guiding the design of M–N–C catalysts. Herein, we summarize the theoretical progress and rational designs of M–N–C catalysts for NRR. The fundamental mechanisms of NRR are introduced, and the activity, selectivity, and stability exhibited by the M–N–C catalysts are analyzed in depth. Additionally, several design strategies for M–N–C catalysts are provided, including adjusting the central metal atoms, regulating the coordinative environments, and applying computational data-driven approaches to optimize the structures of M–N–C catalysts. Finally, a summary and outlook of M–N–C catalysts for NRR are given. Full article

Egypt’s largest coastal lagoon, Manzala Lagoon, has undergone severe degradation due to sediment infilling, aquatic vegetation proliferation, and untreated wastewater. It has shrunk from 805 km² in 1985 to 525 km² by 2017, with poor water quality and heavy metal accumulation. The 2017–2022 restoration project deepened the lagoon to 3–4 m, restoring 750 km² of open water and temporarily improving water quality. However, the reuse of dredged sediments to construct 13 elongated sand barriers and man-made islands inadvertently created semi-isolated sub-basins, disrupting east–west circulation, fostering localized stagnation, and coinciding with vegetation resurgence and seasonal algal blooms. This study employs coupled CMS-Flow and CMS-Wave modeling to evaluate hydrodynamic conditions and test innovative restoration strategies. Four scenarios were analyzed: pre-purification (2017), post-intervention project (2025), and two proposed interventions aimed at restoring connectivity, either through complete barrier removal or selective channel excavation, to enhance east–west water circulation and reduce stagnation. This study demonstrates that targeted, data-driven interventions can rapidly restore water circulation, revive ecological function, and optimize management strategies, providing a conceptually transferable framework for hydrodynamic assessment and sustainable management of coastal lagoons subject to similar anthropogenic pressures. Full article