Search Results (742)

As a potential strategic resource of critical metals, deep-sea cobalt-rich crusts represent one of the most promising metal reservoirs within oceanic seamount systems, and their metallogenic mechanism constitutes a frontier topic in deep-sea geoscience research. This review focuses on the cobalt-rich crusts from the Magellan Seamount region in the northwestern Pacific and synthesizes existing geological, mineralogical, and geochemical studies to systematically elucidate their mineralization processes and metal enrichment mechanisms from a microstructural perspective, with particular emphasis on cobalt enrichment and its controlling factors. Based on published observations and experimental evidence, the formation of cobalt-rich crusts is divided into three stages: (1) Mn/Fe colloid formation—At the chemical interface between oxygen-rich bottom water and the oxygen minimum zone (OMZ), Mn²⁺ and Fe²⁺ are oxidized to form hydrated oxide colloids such as δ-MnO₂ and Fe(OH)₃. (2) Key metal adsorption—Colloidal particles adsorb metal ions such as Co²⁺, Ni²⁺, and Cu²⁺ through surface complexation and oxidation–substitution reactions, among which Co²⁺ is further oxidized to Co³⁺ and stably incorporated into MnO₆ octahedral vacancies. (3) Colloid deposition and mineralization—Mn–Fe colloids aggregate, dehydrate, and cement on the exposed seamount bedrock surface to form layered cobalt-rich crusts. This process is dominated by the Fe/Mn redox cycle, representing a continuous evolution from colloidal reactions to solid-phase mineral formation. Biological processes play a crucial catalytic role in the microstructural evolution of the crusts. Mn-oxidizing bacteria and extracellular polymeric substances (EPS) accelerate Mn oxidation, regulate mineral-oriented growth, and enhance particle cementation, thereby significantly improving the oxidation and adsorption efficiency of metal ions. Tectonic and paleoceanographic evolution, seamount topography, and the circulation of Antarctic Bottom Water jointly control the metallogenic environment and metal sources, while crystal defects, redox gradients, and biological activity collectively drive metal enrichment. This review establishes a conceptual framework of a multi-level metallogenic model linking macroscopic oceanic circulation and geological evolution with microscopic chemical and biological processes, providing a theoretical basis for the exploration, prediction, and sustainable development of potential cobalt-rich crust deposits. Full article

Silver nanoparticles (AgNPs) possess distinct physicochemical characteristics and demonstrate high antibacterial potential that highlights them as promising alternatives against a wide range of pathogens. The immense antibacterial potential of AgNPs is primarily attributed to the release of silver ions that lead to the disruption of bacterial cell membrane, generation of reactive oxygen species (ROS), inhibition of protein synthesis and interference with DNA replication. Variations in AgNPs’ shape, size, and surface characteristics are also considered key factors determining their effectivity as well as specificity. AgNPs are considered potent antibacterial agents, including against antibiotic- and drug-resistant strains. However, inappropriate dosages or unoptimized application of may result in potential toxicity, consisting one of the main drawbacks of the AgNPs’ safer administration. This article reviews the recent literature on the antibacterial potential of AgNPs, focusing on their broad mechanisms of action, applicability, especially in agriculture, biomedical and environmental fields, toxicity and future perspectives. Full article

A treatment process was developed for effluents from direct physical lithium-ion battery (LIB) recycling with a focus on the removal of organic contaminants. The high chemical oxygen demand to biological oxygen demand ratio (COD/BOD₅) of 3.9–4.6 indicates that biological treatment is not feasible. Therefore, three advanced oxidation processes were evaluated: UV/H₂O₂ oxidation, the Fenton process and electrochemical oxidation. Two target scenarios were considered, namely compliance with the limit for discharge into the sewer system (COD = 800 mg/L) and compliance with the stricter limit for direct discharge into surface waters (COD = 200 mg/L). Under the investigated conditions, UV/H₂O₂ oxidation and the Fenton process did not meet the required discharge limits and exhibited high chemical consumption. In contrast, electrochemical oxidation achieved both discharge criteria with a lower energy demand, requiring 32.8 kWh/kgCOD_removed for sewer discharge and 95.3 kWh/kgCOD_removed for direct discharge. An economic assessment further identified electrochemical oxidation as the most cost-effective option, with treatment costs of EUR 6.63/m³, compared to EUR 17.31/m³ for UV/H₂O₂ oxidation and EUR 28.66/m³ for the Fenton process. Overall, electrochemical oxidation proved to be the most efficient and environmentally favorable technology for treating wastewater from LIB recycling, enabling compliance with strict discharge regulations while minimizing the chemical and energy demand. Full article

Cracking occurred in the surface coating of a screw rotor during shale gas well operations. To determine whether the coating cracks could contribute to the failure of the 42CrMo substrate, the microstructure and morphology of surface cracks and local corrosion pits were examined and analyzed using a metallographic microscope, an SEM, and an EDS. To investigate the cross-sectional morphology and elemental distribution of corrosion pits, EDS mapping was performed. The composition of the corrosion products was characterized using Raman spectroscopy and XPS. In addition, four-point bend stress corrosion tests were conducted on screw rotor specimens under simulated service conditions. The results indicate that the P and S contents in the screw rotor substrate exceeded the specified limits, whereas its tensile and impact strengths satisfied the standard requirements. The microstructure consisted of tempered sorbite and ferrite, along with a small amount of sulfide inclusions. The corrosion products on the fracture surface were primarily identified as FeOOH, Fe₃O₄, and Cr(OH)₃. All specimens failed during the four-point bend tests. The chlorine (Cl) content in the corroded regions reached up to 8.05%. These findings demonstrate that the crack resistance of the 42CrMo screw rotor was markedly reduced under the simulated service conditions of 130 °C in a saturated, oxygenated 25% CaCl₂ solution. The study concludes that stress concentration induced by sulfide inclusions in the screw rotor, together with the combined effects of chloride ions, dissolved oxygen, and applied load, promotes the initiation and propagation of stress corrosion cracking. Therefore, it is recommended to strictly control the chemical composition and inclusion content of the screw rotor material and to reduce the oxygen content of the drilling fluid, thereby mitigating the risk of corrosion-induced cracking of the rotor. Full article

Developing electrocatalysts that are efficient and durable for the oxygen evolution reaction (OER) is essential for improving the energy efficiency of alkaline water splitting. Spinel-type transition-metal oxides have emerged as promising non-noble alternatives; however, their catalytic performance is often limited by sluggish charge transport and insufficient utilization of active sites. Herein, we present a systematic comparative study of electrodeposited Co₃O₄ (CO-300) and Cu-substituted Co₂CuO₄ (CCO-300) nanosheet films directly grown on Ni foam. Structural, morphological, and spectroscopic analyses reveal that Cu²⁺ integration into Co-oxide spinel lattice modifies the local electronic environment and produces a more open and interconnected nanosheet architecture, thereby enhancing conductivity and increasing the density of accessible redox-active sites. As a result, the optimized CCO-300 exhibits superior catalytic performance at higher current densities, along with a smaller Tafel slope (44 mV dec^–1), a larger electrochemically active surface area (ECSA), and reduced charge-transfer resistance compared to CCO-300, indicating accelerated reaction kinetics and improved electron-ion transport. Furthermore, the multistep chronopotentiometry measurements and long-term stability tests over 100 h at current densities of 10 and 250 mA cm^–2 highlight the excellent operational stability of the CCO-300 catalyst. Full article

Graphene oxide (GO) is a carbon-based nanomaterial explored for agricultural and forestry uses, but plant responses are strongly subject to both the dose and the route of exposure. We summarized recent studies with defined graphene oxide (GO) exposures by seed priming, foliar delivery, and root or soil exposure, while comparing annual crops with woody forest plants. Mechanistic progress points to a shared physicochemical basis: surface oxygen groups and sheet geometry reshape water and ion microenvironments at the soil–seed and soil–rhizosphere interfaces, and many reported shifts in antioxidant enzymes and hormone pathways likely represent downstream stress responses. In crops, low-to-moderate doses most consistently improve germination, root architecture, and tolerance to salinity or drought stress, whereas high doses or prolonged root exposure can cause root surface coating, oxidative injury, and photosynthetic inhibition. In forest plants, evidence remains limited and often relies on seedlings or tissue culture. For forest plants with long life cycles, processes such as soil persistence, aging, and multi-seasonal carry-over become key factors, especially in nurseries and restoration substrates. The available data indicate predominant root retention with generally limited root-to-shoot translocation, so residues in edible and medicinal organs remain insufficiently quantified under realistic-use patterns. This review provides a scenario-based framework for crop- and forestry-specific safe-dose windows and proposes standardized endpoints for long-term fate and ecological risk assessment. Full article

This work investigated the effects of gamma irradiation on the adsorption capacities of rice husk (RH) for the removal of Cu²⁺, Cr³⁺, and Zn²⁺ ions from aqueous solutions, with potential applications in wastewater remediation. RH samples were gamma-irradiated at doses up to 40 kGy and characterized using SEM-EDS, XRF, FTIR, XRD, and BET analyses. While morphological and textural changes remained subtle, FTIR and SEM-EDS confirmed the formation and intensification of oxygen-containing functional groups, including –OH, –COOH, and C=O, as well as increased exposure of silica (Si–O) on the surfaces, which substantially enhanced surface reactivity of RH toward metal ions. Batch adsorption experiments revealed that 40-kGy irradiated RH samples (RH-40) exhibited the highest removal efficiencies compared to non-irradiated and lower-dose samples (RH-0, RH-10, RH-20, and RH-30), specifically with improvements of 415% for Cu²⁺, 502% for Cr³⁺, and 663% for Zn²⁺ compared to RH-0, determined at the initial concentration of 10 mg/L. Kinetic studies also showed rapid adsorption within the first 10–15 min, dominated initially by boundary-layer diffusion, followed by chemisorption-driven equilibrium behavior. The pseudo-second-order (PSO) model provided an excellent fit for all metals (R² = 0.999), indicating maximum model-predicted kinetic capacities of 555.56 mg/g (Cu²⁺), 769.23 mg/g (Cr³⁺), and 434.78 mg/g (Zn²⁺). Langmuir isotherms also fitted well (R² = 0.941–0.995), with predicted monolayer capacities of 535.33 mg/g (Cu²⁺), 491.64 mg/g (Cr³⁺), and 318.88 mg/g (Zn²⁺). Freundlich modeling further indicated favorable heterogeneous adsorption, with K_F values of 42.614 (Zn²⁺), 20.443 (Cr³⁺), and 16.524 (Cu²⁺) and heterogeneity factors (n) greater than 1 for all metals. These overall results suggested that gamma irradiation substantially enhanced RH functionality that enabled fast and high-capacity heavy-metal adsorption through surface oxidation and carbon valorization. Gamma-irradiated RH, therefore, represented a promising, low-cost, and environmentally friendly biosorbent for wastewater treatment applications. Full article

Objectives: Despite the increasing scientific evidence regarding the application of Cranberries in dentistry, a comprehensive understanding of their potential benefits, active constituents, and mechanisms of action remains lacking. Consequently, this narrative review aims to meticulously analyze and consolidate the existing scientific literature on the utilization of Cranberries for the prevention and treatment of oral diseases. Materials and Methods: Electronic databases (PubMed, Scopus, and Web of Science) were searched up to October 2025. This review included in vitro, in vivo, and clinical research studies. A two-phase selection process was carried out. In phase 1, two reviewers independently screened titles and abstracts to identify potentially eligible studies. In phase 2, the same reviewers performed the full-text assessments of the eligible articles. Results: Among the 93 eligible articles, most assessed Cranberry use in Cariology (n = 28) and Periodontics (n = 26). Biofilm and microbial virulence factors (n = 46) were the most frequently studied topics. Cranberry extract (n = 32) and high-molecular-weight non-dialyzable material (NDM) (n = 23) were the most evaluated Cranberry fractions. Overall, Cranberry-derived compounds were identified as non-toxic and demonstrated promising antimicrobial activity against dental caries-related microorganisms in preclinical studies (n = 20). Regarding periodontal and peri-implant diseases, Cranberry demonstrated host immune modulator effects, counteracting the inflammatory and destructive mechanisms (n = 8). Additionally, Cranberries presented benefits in reducing the inflammation associated with periodontal disease and temporal mandibular joint lesions (n = 1). Regarding dental erosion, Cranberry inhibited dentin erosion (n = 4); however, no effect was observed on enamel lesions (n = 2). As an antioxidant agent, Cranberry showed effectiveness in preventing dental erosion (n = 18). Beyond that, Cranberry neutralized reactive oxygen species generated immediately after dental bleaching, enhancing bond strength (n = 2) and counteracting the oxygen ions formed on the tooth surface following bleaching procedures (n = 3). In osteoclastogenesis assays, A-type proanthocyanidins inhibited bone resorption (n = 1). In osteogenic analysis, preservation of hydroxycarbonate apatite deposition and an increase in early and late osteogenic markers were observed (n = 2). Conclusions: Cranberry bioactive compounds, both individually and synergistically, exhibit substantial potential for diverse applications within dentistry, particularly in the prevention and management of oral and maxillofacial diseases. This review provides insights into the plausible incorporation of Cranberries in contemporary dentistry, offering readers an informed perspective on their potential role. Full article

The effective remediation of cadmium (Cd) pollution continues to pose a significant challenge in environmental science. Bacteria-loaded biochar (BLBC), a composite material synthesized by immobilizing functional microorganisms onto biochar, has emerged as a promising adsorbent for Cd due to its ability to simultaneously facilitate adsorption and biodegradation. In this study, a manganese (Mn)-oxidizing bacterium (Priestia sp. Z-MLHA-1), isolated from a high-manganese mining area, was successfully used to prepare BLBC. The Cd(II) immobilization performance and underlying mechanisms were systematically investigated. The results showed that bacterial loading significantly optimized the pore structure of the biochar, increasing its specific surface area by 40% and enriching the diversity of surface functional groups. Adsorption experiments demonstrated a strong affinity of BLBC for Cd(II), with a maximum adsorption capacity of 44.17 mg/g. The adsorption behavior followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating a monolayer process dominated by chemisorption. The primary immobilization mechanisms involved complexation with surface oxygen-containing functional groups (e.g., −COOH, −OH), ion exchange, and a synergistic effect between the biochar and the immobilized microorganisms. This material enables efficient Cd(II) removal under environmentally benign conditions, thereby providing a theoretical foundation and technical support for the development of green and sustainable remediation technologies for heavy metal-contaminated water. Full article

Alkaline treatment in 0.2 and 0.4 M NaOH solutions successfully generated controlled mesoporosity into ZSM-5 (Zeolite Socony Mobil-5) zeolite, resulting in average mesopore diameters of approximately 15 and 25 nm, respectively, while preserving the crystalline structure of the zeolite framework. Parent ZSM-5 and its mesoporous derivatives obtained by desilication were used to prepare (Fe species)@(zeolite matrix) composites. The synthesis was carried out by co-precipitating Fe²⁺/Fe³⁺ ions onto both parent and desilicated ZSM-5 matrices under oxygen-free conditions. Comprehensive characterization by X-ray diffraction, scanning electron microscopy, N₂ adsorption, vibrating-sample magnetometry, ⁵⁷Fe Mössbauer spectroscopy, and diffuse reflectance UV–Vis spectroscopy revealed that the degree of introduced mesoporosity dramatically influences the size, dispersion, phase composition, and oxidation state of the iron-containing nanospecies. On purely microporous ZSM-5, relatively large (~15 nm) partially oxidized magnetite nanoparticles are formed predominantly on the external surface, exhibiting superparamagnetism at room temperature (Mₛ = 11 emu/g) and a band gap of 2.12 eV. Increasing mesoporosity leads to progressively smaller and more highly dispersed iron(III) oxo/hydroxo clusters with significantly lower blocking temperatures and reduced magnetization (down to 0.7 emu/g for Fe@ZSM-5_0.4). All composites display strong visible-light absorption confirming their potential as magnetically separable visible-light-driven photocatalysts for environmental remediation. Full article

The reliable integration of high-performance noble metal interfaces with flexible substrates is a key requirement for wearable electronics. However, achieving uniform, mechanically robust and functionally active coatings on fabric surfaces remains highly challenging. This study reports the atomic-layered-deposition (ALD) growth of platinum (Pt) on textile at low temperatures. Through ozone plasma-assisted activation technology, Pt nucleation can be achieved at 100 °C, forming a dense and defect-suppressed Pt layer that substantially increases the surface oxygen functional groups and enhances binding affinity. The resulting Pt layer also significantly enhances the adsorption behavior and sensing performance of Ti₃C₂T_x MXene gel inks on textile. At the atomic scale, the engineered Pt–MXene interface promotes stronger adsorption of MXene sheets and establishes efficient electron/ion transport pathways within the gel network. Ultimately, the conductive textile treated with Pt functionalized layers (MXene/Pt@textile) exhibits significantly enhanced sensing sensitivity and signal stability, enabling precise detection of human motions, pressure, and subtle physiological vibrations. The synergistic effect of ALD Pt layers and MXene gel inks creates a textile platform combining robustness, breathability, and high responsiveness. Full article

Cancer remains a severe global health threat, with traditional therapies often plagued by limited efficacy and significant side effects. The emergence of nanotechnology, particularly metal-doped nanomaterials, offers a promising avenue for integrating diagnostic and therapeutic functions into a single platform, enabling a theranostic approach to oncology. This article explores the design and application of various metal-doped nanosystems, including gadolinium-doped selenium molybdenum nanosheets for magnetic resonance/photoacoustic dual-mode imaging and photothermal therapy, and metal-doped hollow mesoporous silica nanoparticles that leverage the tumor’s acidic microenvironment to release ions for catalytic generation of reactive oxygen species. Despite their promise, the limited enzyme-like activity of some nanozymes, insufficient endogenous hydrogen peroxide in tumors, and the tumor microenvironment’s defensive mechanisms, such as high glutathione levels, can restrict therapeutic efficacy. Looking forward, the outlook for the field is contingent upon advancing material engineering strategies. Future research should prioritize the development of intelligent, multifunctional nanoplatforms that can dynamically respond to and remodel the tumor microenvironment. Innovations in surface modification for enhanced targeting, alongside rigorous preclinical studies focused on safety and standardized manufacturing, are crucial for bridging the gap between laboratory research and clinical application, ultimately paving the way for personalized cancer medicine. Full article

Laser slicing has emerged as a promising low-kerf and low-damage technique for SiC wafer fabrication; however, its effects on the crystal integrity, near-surface modification, and charge-transport properties require further clarification. Here, a heavily N-doped 4° off-axis 4H-SiC wafer was sliced using an ultraviolet (UV) picosecond laser, and both laser-irradiated and laser-sliced surfaces were comprehensively characterized. X-ray diffraction and pole figure measurements confirmed that the 4H stacking sequence and macroscopic crystal orientation were preserved after slicing. Raman spectroscopy, including analysis of the folded transverse-optical and longitudinal-optical phonon–plasmon coupled modes, enabled dielectric function fitting and determination of the plasmon frequency, yielding a free-carrier concentration of ~3.1 × 10¹⁸ cm⁻³. Hall measurements provided consistent carrier density, mobility, and resistivity, demonstrating that the laser slicing process did not degrade bulk electrical properties. Multi-scale Atomic Force Microscopy (AFM), Angle-Resolved X-Ray Photoelectron Spectroscopy (ARXPS), Secondary Ion Mass Spectrometry (SIMS), and Transmission Electron Microscopy (TEM)/Selected Area Electron Diffraction (SAED) analyses revealed the formation of a near-surface thin amorphous/polycrystalline modified layer and an oxygen-rich region, with significantly increased roughness and thicker modified layers on the hilly regions of the sliced surface. These results indicate that UV laser slicing maintains the intrinsic crystalline and electrical properties of 4H-SiC while introducing localized nanoscale surface damage that must be minimized by optimizing the slicing parameters and the subsequent surface-finishing processes. 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

In this study, boron was introduced into bamboo-derived porous carbon (BPC) through dry thermal treatment using boric acid. During heat treatment, boric acid was converted to B₂O₃, which subsequently interacted with the oxygen-containing surface groups of BPC, leading to the formation and evolution of B–O–B and B–C bonds. This boron-induced bonding network reconstruction enhanced π-electron delocalization and surface polarity, while maintaining the intrinsic microporous framework of BPC. Among the prepared samples, B-BPC-1 exhibited an optimized balance between the conductive domains and defect concentration, resulting in lower internal resistance and improved ion transport behavior. Correspondingly, B-BPC-1 delivered a better capacitive performance than both undoped BPC and commercial activated carbon. These results indicate that controlling boron incorporation under appropriate heat-treatment conditions effectively improves charge-transfer kinetics while maintaining a stable pore morphology. The proposed dry thermal doping method provides a practical and environmentally benign route for developing high-performance porous carbon electrodes for electric double-layer capacitor applications. Full article