Search Results (5,194)

Photodynamic antibacterial therapy presents a promising strategy for combating bacterial infections due to its non-invasive nature and low potential for inducing resistance. In this work, we developed a series of electron beam-modified graphitic carbon nitride (g-C₃N₄, CN) and titanium carbide (Ti₃C₂, TC) nanocomposites, which were subsequently incorporated into polyvinyl alcohol/sodium alginate (PVA/SA) hydrogels through physical cross-linking. The optimized 200CN/1TC composite hydrogel (where 200CN denotes 200 kGy irradiation dose, and 1TC represents 1 wt% TC content) maintained excellent biocompatibility with cell viability exceeding 80% even at the highest nanomaterial loading (8% 200CN/1TC). Notably, the 8% 200CN/1TC composite hydrogel displayed substantial antibacterial activity, forming inhibition zones of 12.3 mm and 10.8 mm against Staphylococcus aureus and Escherichia coli, respectively. The improved performance may be explained by the combined effects of enhanced electron transfer between the component materials and the unique two-dimensional structure of the nanocomposites, though further investigation is required to fully elucidate the underlying mechanisms. This study provides a feasible approach for developing efficient antibacterial hydrogel systems and offers valuable perspectives on the design of nanomaterial-based biomedical materials for wound healing and infection control applications. Full article

Microbial fuel cells (MFCs) convert the chemical energy of biomass into electricity through microbially driven redox reactions. We evaluated a single-chamber, membrane-less MFC fed with sugarcane molasses and inoculated with a two-member consortium: Saccharomyces cerevisiae (glucose → ethanol fermentation) and Acetobacter aceti (ethanol → acetate oxidation). Three anode–cathode pairs were tested—bronze–Zn, copper–Zn, and graphite–Zn—across 27 units and 20 operating cycles. During ethanol oxidation, A. aceti oxidizes ethanol to acetic acid and, in our configuration, this biocatalytic step is designed to contribute electrons to the bronze, copper, or graphite anodes. These electrons, together with those generated by galvanic reactions in the electrode pair, flow through the external circuit to the zinc cathode, where oxygen reduction closes the circuit. The cells reached open-circuit potentials > 0.8 V, with performance following the hierarchy graphite–Zn > copper–Zn > bronze–Zn, consistent with the superior biocompatibility and lower corrosion of carbonaceous anodes. Multivariate analysis using PLS-SEM confirmed that redox indicators and electrode composition were strong determinants of voltage output (R² = 0.911) and demonstrated high predictive relevance (Q² = 0.906) for the voltage construct. These findings show that coupling yeast fermentation with acetic acid–bacteria oxidation enables synthetic-mediator-free electron transfer in a simple single-chamber configuration and shows that electrode material selection is a primary lever for achieving stable potentials for biomass valorization. Full article

Coalbed methane (CBM) reservoirs are characterized by low permeability and poor methane desorption, which limit recovery rates. To address this, a novel graphite composite thermally conductive proppant is proposed, offering enhanced thermal conductivity and mechanical performance. The composite consists of porous ceramsite as a mechanical scaffold, epoxy resin as an interfacial binder, and graphite as a thermally conductive reinforcement. The effects of graphite content and resin dosage on the composite’s structure, thermal conductivity, suspension stability, surface wettability, and interfacial adhesion are systematically investigated. The results show that an optimized formulation with 20 wt% graphite and 1.0 g epoxy resin achieves a thermal conductivity of 3.8 W/(m·K)—6.3 times that of pure ceramsite—along with an improved thermal response under simulated stimulation, good suspension stability (suspension ratio of 0.53 in 0.2 wt% guar gum solution), a hydrophobic surface (contact angle 74.9°) to mitigate water lockup, and strong interfacial adhesion (125 nN under 2500 nN load) for durable proppant performance. Microscopic analysis confirms the formation of a continuous “resin–graphite–ceramsite” three-phase interface and a percolative thermal conductive network. This study provides a feasible design strategy for high-performance thermally conductive proppants and demonstrates their potential for application in the hydraulic fracturing of unconventional oil and gas reservoirs. Full article

To evaluate cross-platform measurement consistency and diagnostic threshold requirements in shear wave elastography (SWE), this study presents a robotically controlled, phantom-based validation framework to quantify and interpret inter-vendor variability that limits clinical standardisation. A custom-fabricated polyvinyl chloride-graphite phantom containing eight spherical inclusions (15–25 mm diameter, 25–95 mm depth, 23.53–259.58 kPa stiffness), representing breast tissue mechanical properties, was evaluated using Samsung HS50 and Aixplorer ultrasound systems. Robotic automation standardised probe positioning and contact, eliminating operator-dependent variability and enabling direct, system-level comparison. Cross-platform reproducibility, accuracy against mechanically validated ground truth, and diagnostic threshold performance were assessed across 80 measurements. Both systems demonstrated excellent intra-machine reproducibility (coefficient of variation: Samsung 0.42%, Aixplorer 0.46%) with strong inter-machine correlation (r = 0.9951, p < 0.0001). However, systematic bias of 7.05 kPa and 95% limits of agreement spanning 38.7 kPa revealed substantial cross-platform measurement differences. All phantom inclusions (8/8) measured below their assigned ground truth stiffness on both systems, with systematic underestimation ranging from 0.33 kPa to 109.57 kPa, indicating parameter-dependent measurement distortion linked to inclusion size, depth, and stiffness. Dynamic range compression was observed (Samsung: 68.7%, Aixplorer: 59.1% of true phantom range), providing a mechanistic explanation for diagnostic threshold instability. This study contributes an interpretable validation methodology that links SWE measurement bias to physical lesion properties and imaging system characteristics, rather than relying on correlation alone. Despite strong reproducibility, the observed system-dependent bias demonstrates that SWE measurements are not directly transferable across ultrasound platforms, and system-specific collaboration is required to ensure reliable clinical interpretation. Full article

Wood, which is flammable, is commonly used as a building material and can be improved using a suitable surface treatment. A promising coating solution is polyurea, featuring properties like flexibility, mechanical resistance, resistance against water, etc., but it is also easily flammable. Expandable graphite (EG) is effective as a flame retardant and environmentally suitable. In this study, we studied the suitability of polyurea improved with EG. Spruce wood samples with dimensions of 50 mm × 40 mm × 10 mm were divided into eight groups, each including five samples. Each group was subjected to two applications of polyurea and EG in various combinations to examine the best combination with the lowest mass loss. The second component of the experiments aimed to examine the effectiveness of EG, which was applied in different weights. During the experiments, samples were thermally loaded in an apparatus for 10 min, where a heat flux of 30 kW·m⁻² was applied to the sample surface and the mass loss was continuously recorded. Lastly, thermal analysis was performed. The best results were observed for the combination of NEOPROOF mixed with 0.3 g of EG covered with NEODUR. The thermal analysis results revealed substantial differences: NEOPROOF, a polyurea, had only one degradation step, while NEODUR, which also contained polyurethanes, decomposed in several steps. Full article

In response to thermal failure risks in ultra-high voltage (UHV) bushing online monitoring devices and maintenance equipment—caused by high heat generation of electronic components and the intrinsically low thermal conductivity of conventional resin encapsulation materials—this study proposes a novel modification strategy based on flash Joule heating (FJH). Distinct from conventional interface modification methods, the proposed approach enables cross-scale, in situ microsoldering between multi-walled carbon nanotubes (MWCNTs) and carbon fibers (CFs), constructing a multiscale reinforcement network with integrated thermal transport and mechanical load transfer pathways. The transient ultra-high-temperature thermal shock generated by FJH not only effectively removes inert impurities on CF surfaces but also drives carbon structural reconstruction, enabling graphitic-level welding of MWCNTs onto the fiber surface. This micro-welded architecture fundamentally differs from traditional filler dispersion or interface coating strategies, which often suffer from the trade-off between interfacial thermal transport and mechanical bonding. By contrast, the FJH-induced carbon–carbon bonded nodes form a continuous conductive and load-bearing network at the micro–nano scale. Characterizations using scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) confirm successful in situ welding of MWCNTs onto CF surfaces. Meanwhile, FJH treatment effectively removes oxygen-containing functional groups and surface impurities. Analysis of carbon bonding evolution indicates that the welding efficiency reaches its maximum at 90 V. Macroscopic performance tests demonstrate that, compared with epoxy resin, the thermal conductivity of the multiscale reinforced system increases by approximately 168%, while the mechanical strength improves by 62.72%. This study provides new theoretical insights and technical pathways for the development of next-generation polymer composite materials with both high thermal conductivity and high mechanical strength. Full article

An ultrafast laser system combined with an optical delay line allowed ablation and in-scription at 1 kHz and 1 GHz pulse burst within transparent polyimide films. The two-photon-induced absorption results in clean surface ablation, while inscription results in polymer decomposition, creating carbonised regions within the polymer. Three pulse bursts at 1 GHz increased the observed coupling to the material significantly. Modified regions (with linewidths down to a few microns) were investigated using optical microscopy, white light interferometry, SEM and Raman spectroscopy, supporting the increasing carbon density relative to the pristine polymer. As depth of field was only a few microns at high NA, 3D micro-structuring was achieved. Polymer decomposition produces gaseous products, resulting in internal stress and thus affecting inscription fidelity. An inscribed subsurface electrode with dimensions of 5 mm × 0.3 mm × 3 μm connected to conducting vias had a resistance of R = 10.6 ± 0.2 kΩ, along with resistivity of ρ ~ 0.19 Ω cm; hence, it had DC conductivity, σ ~ 5.3 Scm⁻¹. This conductivity is similar to that of bulk graphite and could well form the basis of future flexible sensors, demonstrating single-step 3D subsurface inscription of carbon or laser-induced graphene structures. Full article

This study systematically investigates the mineralogical, spectral, and geochemical characteristics of Guatemalan lavender jadeite and black omphacite to elucidate their coloration mechanisms and genetic origins. Lavender samples are primarily composed of jadeite, which derives its color from synergistic effects involving Mn³⁺ and Fe²⁺-Ti⁴⁺ charge transfer (554–614 nm). In contrast, black samples are dominated by omphacite, which owes its dark hue to Cr³⁺ (670 nm) and Fe²⁺-Fe³⁺ charge transfer (857 nm). Chemically, lavender jadeite exhibits higher Na₂O and Al₂O₃, approaching the jadeite end-member composition, whereas black omphacite is enriched in CaO, MgO, and FeO. Trace element analyses reveal low overall abundances, with black omphacite showing synchronous LREE and HREE depletion forming a “bulge-shaped” pattern, while lavender jadeite displays N-MORB-like REE distributions. Guatemalan jadeites are distinguished from Myanmar counterparts by Y enrichment. The identification of graphite and CH₄ and CO₂ fluid inclusions indicates formation in an organic-rich reducing environment. Cathodoluminescence zoning and abundant fluid inclusions support a direct crystallization genesis from high-pressure fluids (P-type) in subduction zones. This study establishes key constraints for origin discrimination and genetic classification of Guatemalan lavender jadeite and black omphacite. Full article

This study investigates how graphitic carbon nitride (g-C₃N₄), derived from melamine, urea, and thiourea, degrades recalcitrant pharmaceuticals. Among the materials used, g-C₃N₄ derived from urea showed the highest degradation of methyl orange (60.25%). When calcined with biochar derived from onion flower seed-cover biomass via pyrolysis and further activated with potassium hydroxide (KOH), it showed better adsorption and photodegradation results of 92.59%, 84.44%, 68.11%, and 61.11% for tetracycline, cefixime, ciprofloxacin, and carbamazepine, respectively. These results emphasize the potential of biochar-g-C₃N₄ composites as sustainable photocatalysts for water treatment focused on removing recalcitrant pharmaceutical contaminants. Full article

This study aims to develop an innovative electrochemical genosensor based on activated biochar (ABC) derived from the biomass of the seaweed Sargassum spp. The synthesis process begins with the pyrolysis of Sargassum spp. at 500 °C to obtain biochar (BC), which is chemically activated with nitric acid (HNO₃). The physicochemical properties of the resulting material, such as morphology and surface area, were characterized using techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and the Brunauer–Emmett–Teller (BET) method for surface area. BET results showed an increase in surface area from 22.9367 ± 0.0879 m²/g (BC) to 159.2915 ± 2.2641 m²/g (ABC). For the development of the genosensor, a hydrolyzed collagen gel matrix enriched with ABC is created. This nanostructured, biocompatible mixture is used to immobilize a DNA probe on a graphite electrode, employing the large surface area of ABC and the formation of a functional HC-based coating. The system’s viability was evaluated by cyclic voltammetry (CV), which showed changes in the maximum anodic peak current (Ipa) during fabrication: 27.78 ± 1.87 μA for the bare electrode, 35.25 ± 1.24 μA for ABC 30%, and 39.25 ± 1.84 μA for HC + ABC 30%. After ssDNA immobilization and hybridization to dsDNA, Ipa decreased to 28.81 ± 1.565 μA and 23.10 ± 1.25 μA, respectively. Finally, hematoxylin (Hx) was used as an intercalating indicator from hybridization, reducing the maximum anodic peak current to 15.51 ± 1.13 μA, consistent with additional interfacial limitations associated with dsDNA formation. Overall, the developed system demonstrates a sustainable, promising platform for molecular diagnostics in electrochemical DNA biosensor development. Full article

The present study addresses the development and characterization of an in-chip laser-induced graphene (LIG)-based sensor that combines optical and electrochemical transduction techniques as a proof of concept for the advancement of novel point-of-care (POC) devices. In recent years, LIG has emerged as a suitable material for next-generation diagnostic devices due to the increasing need for effective and easily accessible biosensing platforms. In this context, the presented sensors were fabricated and tested with an increasing number of laser exposures to understand how the resulting morphology, degree of graphitization, defects, and electrical resistance of LIG electrodes affect the electrochemical and optical sensing performance. To validate the dual sensor, ferrocyanide ([Fe(CN)₆]⁴⁻) was used as a redox probe and [(4-Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran] (DCM) was used as model dye to explore the electrochemical and optical sensing capabilities. Finally, we showcase the sensor’s ability to perform simultaneous optical and electrochemical on-time detection and analysis of the ferrocyanide electro-oxidation process, underscoring its potential to be used as a dual optical/electrochemical POC device. Full article

Green nephrite of the serpentine-replacement type often consists predominantly of the actinolite–tremolite series, with minor minerals such as uvarovite, grossular, chromite, magnetite, diopside, zircon, apatite, epidote, graphite, and phlogopite, which commonly reduce gem quality. However, nephrite from the Polar deposit in Canada represents an exception. This material consists mainly of the actinolite–tremolite series, with minor Cr-bearing grossular garnet and chromite. Actinolite–tremolite occurs as aggregates of fine fibers without obvious orientations, surrounding centimeter-scale, vivid green, berry-shaped garnet aggregates, within which residual chromite islands were observed. This vivid green color occurs over extensive areas, enhancing rather than reducing gem quality. Garnets contain 0.53–0.90 Cr apfu with lower Fe content, whereas amphiboles exhibit 0.01–0.06 Cr apfu and 0.46–0.87 Fe²⁺ apfu, values significantly higher than that observed in the adjacent grossular. Garnet is a minor mineral occasionally existing in green nephrite; however, the discovery of berry-shaped, vivid green garnet has only been reported at this location. The fine-grained, Al-rich garnet aggregates with relatively low Cr and Fe content suggest that a continuous replacement reaction potentially occurred. A more multifaceted value assessment framework that emphasizes the uniqueness of artistic expression and cultural connotation are proposed. Full article

Zinc(II) bis(8-hydroxyquinolinate) (Zn(HQ)₂) and 1,10-phenanthroline (phen) were combined to fabricate an organic semiconductor in a bulk heterojunction architecture and subsequently embedded in a poly 3,4-ethylene dioxythiophene–polystyrene sulfonate (PEDOT–PSS) matrix. The resulting Zn(HQ)₂-phen/PEDOT–PSS was deposited as a film upon tin-oxide-coated glass and graphite-covered Tetra Pak (TP)-recycled substrates for the manufacture of organic photoconductive devices. The topographical and micromechanical characteristics of the hybrid films were assessed by atomic force microscopy, with an average roughness of 5.6 nm, maximum tensile strength of 7.95 MPa, and Knoop microhardness of 14.7. The fundamental energy gap (E_g) was determined employing the Kubelka–Munk function, with E_g of 3.5–3.8 eV. These results were complemented with a computational DFT molecular orbital analysis of the species involved in the hybrid semiconductor. The devices were electrically characterized under UV irradiation conditions, obtaining the current–voltage and power–voltage relationships. The maximum current in the TP–graphite device is 1.8 × 10⁻² A and 1.1 × 10⁻² A in the device on glass–ITO. Zn(HQ)₂-phen/PEDOT–PSS film presents its own operating regimes relating to a photoconductor or flexible photoresistor. The power in the device on glass–ITO is 120 mW and 113 mW for shortwave and longwave, respectively, and in the device on TP–graphite, it is 198 mW and 139 mW. Full article

This study presents the development of an environmentally benign and economically viable methodology for the synthesis of graphene-containing carbon materials derived from renewable agricultural residues, specifically walnut shells, rice husks, and apricot stones. The proposed synthesis route involves sequential stages of controlled pre-carbonization, desilicification, chemical activation with potassium hydroxide (KOH), and subsequent mild exfoliation, resulting in the formation of few-layer graphene with a high degree of structural ordering. Pre-carbonization carried out at 523–573 K, followed by activation at 1123 K, yields graphene sheets exhibiting a specific surface area of 1300–1800 m²/g, a carbon content of 60–90%, and an average pore diameter below 100 nm. The synthesized materials were subjected to comprehensive physicochemical characterization using BET surface area analysis, Raman spectroscopy, FTIR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic absorption flame emission spectrophotometry. Raman spectroscopic analysis revealed an I_G/I_2D intensity ratio of approximately 1.5–2.0, indicating the presence of graphene structures consisting of approximately four to five layers. To enhance adsorption performance, the graphene-containing carbon materials were further functionalized with sulfuric acid, and the successful incorporation of surface functional groups was confirmed by FTIR spectroscopy. The adsorption properties of the functionalized graphene-containing carbon materials were evaluated in aqueous solutions containing sodium, potassium, calcium, and magnesium salts, demonstrating adsorption efficiencies of up to 80%. Compared to conventional biomass-derived graphene synthesis methods, the developed approach produces materials with enhanced porosity, higher graphitic ordering, and improved chemical purity. These characteristics highlight the strong potential of the synthesized graphene-containing carbon materials for applications in energy storage systems, adsorption-based water purification technologies, and environmentally sustainable nanotechnological applications. Full article

Due to its antioxidant and immunomodulatory properties, using passion fruit seed oil (PFSO) is a promising strategy to mitigate the effects of heat stress in laying hens, potentially optimizing the absorption of essential minerals such as selenium (Se) and zinc (Zn). Therefore, this study investigated the profile of selenium- and zinc-binding proteins (Se/Zn-BPs) in the hepatic proteome of Lohmann White laying hens (26 weeks old, n = 96) subjected to heat stress and whose diet was supplemented with 0.9% PFSO, using a metalloproteomic approach that combined two-dimensional electrophoresis (2D PAGE), graphite furnace atomic absorption spectrometry (GFAAS), and liquid chromatography–tandem mass spectrometry (LC-MS/MS). The experimental design was a 2 × 2 factorial (temperature: thermoneutral/stress × diet: control/PFSO) design. After 84 days, liver samples were collected and subjected to metalloproteomic analyses. GFAAS analysis showed higher concentrations of Zn and Se in the protein pellets and in 11 specific protein spots of the supplemented groups (thermoneutral/PFSO and stress/PFSO). LC-MS/MS analysis identified 56 Se/Zn-BPs, with a predominance of heat shock chaperones (HSPs) and proteins involved in energy metabolism. In conclusion, PFSO supplementation modulates Se and Zn absorption, promoting a mineral balance that optimizes immune and antioxidant defense processes. This mechanism can lead to a positive impact on the health and productive performance of laying hens under heat stress. Full article