Search Results (500)

Advancements in flexible, low-cost, and recyclable alternatives to transparent conductive oxides (TCOs) are critical challenges in the sustainability of third-generation solar cells. This work introduces a copper mesh-based transparent electrode for dye-sensitized solar cells, replacing conventional fluorine doped-tin oxide (FTO)-coated glass to simultaneously reduce spectral reflection losses, enhance mechanical flexibility, and enable material recyclability. Titanium dioxide (TiO₂) photoanodes were synthesized and directly deposited onto the mesh via a single-step, low-energy ball milling process, which eliminates TiO₂ paste preparation and high-temperature annealing while reducing fabrication time from over three hours to 30 min. Structural and surface analyses confirmed the deposition of high-purity anatase-phase TiO₂ with strong adhesion to the mesh branches, enabling improved dye loading and electron injection pathways. Optical studies revealed higher visible light absorption for the copper mesh compared to FTO in the visible range, further enhanced upon TiO₂ and Ru-based dye deposition. Electrochemical measurements showed that TiO₂/Cu mesh electrodes exhibited significantly higher photocurrent densities and faster photo response rates than bare Cu mesh, with dye-sensitized Cu mesh achieving the lowest charge transfer resistance in impedance analysis. Techno–economic and sustainability assessments revealed a decrease of 7.8% in cost and 82% in CO₂ emissions associated with the fabrication of electrodes as compared to conventional TCO electrodes. The synergy between high conductivity, transparency, mechanical durability, and a scalable, recyclable fabrication route positions this architecture as a strong candidate for next-generation dye-sensitized solar modules that are both flexible and sustainable. Full article

The acid number is widely recognized as one of the most essential and frequently used indicators for evaluating the degradation state of lubricants. Changes in acid number serve as a direct reflection of the oil’s oxidative deterioration. Conventional prediction methods, however, often neglect the coupling effects among multiple physical factors and lack sufficient dynamic adaptability. Therefore, this study proposes a method for predicting the variation trend of lubricating oil acid number by integrating an Adaptive Neuro-Fuzzy Inference System (ANFIS) with Subtractive Clustering (SC), establishing an SC-ANFIS-based predictive model. The subtractive clustering technique automatically determines the number of fuzzy rules and initial parameters directly from the dataset, thereby eliminating redundant rules and simplifying the model architecture. The SC-ANFIS model further optimizes the parameters of the fuzzy inference system through the self-learning ability of neural networks. Lubricant aging tests were conducted using a laboratory oxidation stability tester. Regular sampling was carried out to acquire comprehensive lubricant performance degradation data. The input variables of the model include the current acid number, carbonyl peak intensity, metal element concentrations (Fe and Cu), viscosity, and water content of the lubricating oil, while the output variable corresponds to the rate of change in the acid number of the lubricating oil relative to the previous time step. The proposed model demonstrates effective prediction of the lubricating oil acid number variation trend. Posterior difference tests confirmed its high predictive accuracy, with all three evaluation metrics—RMSE, MAE, and MAPE—outperforming those of the BP model. Full article

Adventitious rooting is a key step for the clonal propagation of many economically important horticultural and woody species. Accumulating evidence suggests that nitric oxide (NO) serves as a key signaling molecule with key roles in root organogenesis. However, the role of NO in adventitious root development and its underlying mechanism in sweetpotato cuttings remain to be clarified. In this study, a pot experiment was conducted using hydroponically cultured sweetpotato cuttings (Ipomoea batatas cv. ‘Jin Ganshu No. 9’) treated with different concentrations of sodium nitroprusside (SNP, an NO donor) solution (0, 10, 50, 100, 200, and 500 μmol·L⁻¹). Three treatments were established: Control, SNP (the optimal concentration of SNP), and SNP + 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO, an NO scavenger). The results showed that NO promoted adventitious rooting in a dose-dependent manner, with the maximal biological response observed at 100 μM SNP. At this concentration, the root number and length of adventitious roots increased by 1.22 and 2.36 times, respectively, compared to the control. SNP treatment increased fresh root weight, dry root weight, the content of soluble sugar, soluble protein, chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (a + b) [Chl(a + b)], as well as the activities of peroxidase (POD), polyphenol oxidase (PPO), and indole acetic acid oxidase (IAAO). It also enhanced the levels of maximum fluorescence (Fm), maximum photochemical efficiency of photosystem II (Fv/Fm), absorbed light energy (ABS/RC), trapped energy flux (TRo/RC), and electron transport flux (ETo/RC), while decreasing starch content and initial fluorescence (Fo). On the 7th day, the SNP treatment significantly enhanced several biochemical parameters compared to the control. We observed an increase in many of the parameters: POD activity by 1.35 times, PPO activity by 0.55 times, chlorophyll content (Chl a by 0.66 times, Chl b by 0.22 times, and Chl a + b by 0.57 times), and photosynthesis parameters by 28–98%. Meanwhile, starch content and Fo in the SNP treatment decreased by 10.77% and 23.86%, respectively, compared to the control. Furthermore, the positive effects of NO on adventitious root development and associated biochemical parameters were reversed by the NO scavenger cPTIO. Additionally, significant and positive correlations were observed between morphological characteristics and most physiological indicators. Collectively, these results demonstrate that NO promotes adventitious root formation, which may be by enhancing rooting-related enzyme activities, improving photosynthetic performance in leaves, and accelerating the metabolism of soluble sugar, soluble protein, and starch. Full article

This article presents the manufacturing technology and mechanical properties of innovative pre-impregnated coatings (PCs). The base materials for PC are powders of metal oxides, non-metals, minerals and thermoplastic non-wovens. PC can be used in the manufacture of composites by methods such as vacuum infusion, autoclave curing or hand lamination. This is possible due to the novel PC structure consisting of a functional layer (FL) and a backing layer (BL). PCs are flexible so that they can be used on curved surfaces. In this work, five types of PC were subjected to a uniaxial tensile test. Depending on the powder used, failure force values ranging from 24.61 N to 28.73 N were obtained. In the next step, the pre-impregnated coatings were applied as a coating in “sandwich” composites made by vacuum infusion, which were subjected to three-point bending (3-PB) and adhesion tests. 3-PB tests proved that the coating remained integral with the substrate, even under high flexural deformation, while the adhesion achieved was in the range of 0.95 MPa to 1.57 MPa. PC can be used in many engineering products, e.g., for the coating of façade panels, roof tiles, automotive parts or rail vehicles, etc. 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

Background: Encapsulating essential oils in polymer-based nanocarriers can improve their stability, solubility, and bioavailability, while maintaining the biological activity of the oil’s active ingredients. In this contribution, we investigated the antiviral activity of Oregano Essential Oil (OEO) in its pure form and encapsulated into nanosized polymeric micelles, based on a poly(ethylene oxide)-block-poly(ε-caprolactone) diblock copolymer. Methods: The effect of encapsulation was evaluated using three structurally different viruses: herpes simplex virus type 1 (HSV-1) (DNA—enveloped virus), human coronavirus (HCoV OC-43) (RNA—enveloped virus), and feline calicivirus (FCV) (RNA—naked virus). The effect on the viral replicative cycle was determined using the cytopathic effect inhibition (CPE) test. Inhibition of the viral adsorption step, virucidal activity, and protective effect on healthy cells were assessed using the final dilution method and were determined as Δlg compared to the untreated viral control. Results: In both studied forms (pure and nanoformulated), OEO had no significant effect on viral replication. In the remaining antiviral experiments, the oil embedded into nanocarriers showed a slightly stronger effect than the pure oil. When the oil was directly applied to extracellular virions, viral titers were significantly reduced for all three viruses, with the effect being strongest for HSV-1 and FCV (Δlg = 3.5). A distinct effect was also observed on the viral adsorption stage, with the effect being most significant for HSV-1 (Δlg = 3.0). Conclusions: Pretreatment of healthy cells with the nanoformulated OEO significantly protected them from viral infection, with the greatest reduction in viral titer for HCoV OC-43. Full article

Thermo-catalytic decomposition (TCD) presents a promising pathway for producing hydrogen from natural gas without emitting CO₂. This process represents a form of fossil fuel decarbonization where the byproduct, rather than being a greenhouse gas, is a solid carbon material with potential for commercial value. This study examines the dynamic behavior of TCD, showing that carbon formed during the reaction first enhances and later dominates methane decomposition. Three types of carbon materials were employed as starting catalysts. Methane decomposition was continuously monitored using on-line Fourier transform infrared (FT-IR) spectroscopy. The concentration and nature of surface-active sites were determined using a two-step approach: oxygen chemisorption followed by elemental analysis through X-ray photoelectron spectroscopy (XPS). Changes in the morphology and nanostructure of the carbon catalysts, both before and after TCD, were examined using high-resolution transmission electron microscopy (HRTEM). Thermogravimetric analysis (TGA) was used to study the reactivity of the TCD deposits in relation to the initial catalysts. Partial oxidation altered the structural and surface chemistry of the initial carbon catalysts, resulting in activation energies of 69.7–136.7 kJ/mol for methane. The presence of C₂ and C₃ species doubled methane decomposition (12% → 24%). TCD carbon displayed higher reactivity than the nascent catalysts and sustained long-term activity. Full article

Chimeric compounds represent a promising strategy in cancer therapy by simultaneously targeting multiple pathways responsible for tumour growth and survival. Their structure comprises two or more pharmacophores connected through suitable chemical linker. These dual or multi-functional drugs can interact with several biological targets for a more pronounced pharmacological effect. In order to identify new multi-targeting agents with anticancer efficacy, we designed and synthesised a series of novel multi-functional molecules by covalently linking antitumor compounds dichloroacetate (DCA) and Nutlin-3a. The design was aimed at addressing two critical events in cancer: (1) the Warburg effect and (2) the dysregulations of protein p53 pathway, both of which are directly linked to the predominant survival and aggressive proliferation of malignant cells. DCA reactivate oxidative phosphorylation by inhibiting mitochondria pyruvate dehydrogenase kinase (PDK), thereby unlocking the Warburg metabolism of cancer cells and its antiapoptosis state. Concurrently, Nutlin-3a restores the protective function of the “genome guardian” p53 protein, by blocking its antagonist oncoprotein E3 ligase MDM2. Chimeric compounds were obtained using a chemoenzymatic multi-step procedure that included a key lipase-catalysed asymmetric reaction. Biological evaluation of the synthesised Nutlin-DCA chimeras in a panel of three cancer cell lines demonstrated promising results in vitro. Specifically, compounds rac-19a, rac-19b, rac-20a, rac-20b and enantioenriched 20a caused a statistically significant reduction in cell viability at micromolar concentrations. These findings suggest that targeting both the Warburg effect and the p53 pathway with a single molecule is a viable approach for future cancer therapeutic development. Full article

Density functional theory calculations are performed to examine the reactivity of the coordinatively unsaturated (NH₃)₄RhO²⁺, (NH₃)₄CoO²⁺, and (NH₃)₄FeO⁺ species with methane and methanol. The ground low-spin state of rhodium oxide provides ideal energetics for the efficient and selective conversion of methane to methanol. The small activation energy barriers for all three steps (H₃C-H activation, CH₃-OH recombination, oxygen reload) promise fast conversion, while the larger activation barrier for the C-H activation of methanol provides the means to kinetically hinder further oxidation to the thermodynamically more favorable formaldehyde. The key finding was that rhodium prefers the 2 + 2 (as opposed to radical) activation mechanism of methane. To maintain the “ideal” electronic structure observed for (NH₃)₄RhO²⁺, we first replaced rhodium with its first-row lower cost counterpart cobalt. The cobalt complex favors a quartet state, which prefers a radical mechanism leading to the formation of methyl radical. This undesired effect vanishes, switching from Co⁴⁺ to Fe³⁺. Possible explanations for the observed trends are provided in terms of electronic structure features of the three metals. The production of methanol from methane has been a topic of intense interest over the past decades and we believe that this work offers new insights for tackling this challenging problem. Full article

Through atomic-scale characterization of a single cobalt atom anchored in a pyridinic N₃ vacancy of graphene (Co-N₃-gra), this study computationally explores three interconnected functionalities mediated by cobalt’s electronic configuration. Quantum-confined molecular prototypes extend prior bulk models, achieving a competitive catalytic activity for CO oxidation via Langmuir–Hinshelwood pathways with a 0.85 eV barrier. These molecular prototypes’ discrete energy states facilitate single-electron transistor operation, enabling sensitive detection of NO, NO₂, SO₂, and CO₂ through adsorption-induced conductance modulation. When applied to lithium–sulfur batteries using periodic Co-N₃-gra, cobalt sites enhance polysulfide conversion kinetics and suppress the shuttle effect, with the Li₂S₂→Li₂S step identified as the rate-limiting process. Density functional simulations provide atomic-scale physicochemical characterization of Co-N₃-gra, revealing how defect engineering in 2D materials modulates electronic structures for multifunctional applications. Full article

Ozonized vegetable oils are gaining attention for their antimicrobial and therapeutic potential, yet the lack of standardized ozonation protocols and incomplete characterization of their chemical profiles hinder clinical translation. In this study, we standardized the ozonation process of sunflower oil and investigated the chemical evolution and antimicrobial efficacy of the resulting products. Ozonation proceeded through a classical three-step mechanism involving the formation of primary ozonides, their decomposition into carbonyl compounds and carbonyl oxides, and subsequent recombination into stable secondary ozonides capable of sustained ozone release with reduced toxicity. Time-course analysis at 100, 240, and 480 min revealed key reaction products, including the appearance of azelaic acid after 240 min, progressive depletion of linoleic acid, and the emergence of 2,5-furandione exclusively after 480 min—indicative of advanced oxidative processes. The formation of hydroperoxides and their secondary degradation into ketones, acids, and epoxides was also observed, with implications for both biological activity and sensory properties. Importantly, the ozonized oil demonstrated potent antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella choleraesuis, Pseudomonas aeruginosa, Candida albicans, and Aspergillus brasiliensis. These findings provide a comprehensive chemical and functional characterization of ozonized sunflower oil and support its development as a standardized antimicrobial agent for therapeutic use. Full article

Ore mining and smelting are often related to environmental pollution. This study provides information about the geochemical features of Technosols at historical mining and metallurgical sites in the Tatra Mountains, southern Poland, evaluating the contents of potentially toxic trace elements (PTTE) and their behaviours in soils, as well as the influence of soil properties on PTTE mobility. Thirteen soil profiles were studied in eight abandoned mining and smelting sites. PTTE concentrations, including rare earth elements (REE), were measured using ICP-MS and ICP-OES. Selected elements (Cu, Zn, Pb, Cd, As, Sb, Ba, Sr, Co, Ni, Mn and Cr) were fractionated using the modified European Community Bureau of Reference (BCR) four-step sequential extraction. Contamination of soils with PTTE was compared against Polish regulatory limits, which were exceeded for Cu, Zn, Pb, Mo, Hg, As, Co, Ni and Ba, with concentrations exceeding limits by 16, 18, 34 and 160 times for Cu, Hg, As and Ba, respectively, in some profiles. Based on geochemical features depending on parent material properties, the soils examined were divided into three groups. Group I Technosols (near-neutral soils developed from Fe/Mn-ore and carbonate-bearing mining waste) were particularly enriched in Co, Ni, Mn and REE. Group II Technosols (acidic soils developed from polymetallic ore-bearing aluminosilicate mining waste) contained elevated concentrations of Cu, Zn, Hg, As, Sb, Bi, Co, Ag, Ba, Sr, U and Th; they contained lower contents of REE than Group I Technosols. Group III Technosols (soils developed in smelting-affected areas and containing metallurgical waste) were rich in Cu, As, Sb, Ba, Hg, Co and Ag and contained the lowest REE contents among the studied soils. Sequential BCR extraction revealed that PTTE mobility varied strongly according to soil group, with higher mobility of Mn, Cu and Zn in acidic polymetallic ore-derived soils (Group II), while carbonate-rich soils (Group I) showed mainly immobile forms. Metallurgical slag-derived soils (Group III) exhibited complex PTTE behaviour controlled by organic matter and Fe/Mn oxides. Soil properties (pH, carbonates and TOC) seem to control PTTE mobility. Full article

This study investigates the insufficient surface hardness of medium-carbon 45 steel and the drawbacks associated with conventional surface modification techniques (e.g., cracking in laser cladding, weak bonding in thermal spraying, restricted thickness in chemical deposition). Series CeO₂-Ni/WC composite claddings (with CeO₂ content ranging from 0.5 to 2.0 wt %) were fabricated via vacuum cladding. The cladding with 0.5 wt % CeO₂ (NWC5) exhibited the lowest porosity (0.0673%) and finest grain size (12.06 nm) and demonstrated the highest microhardness (1042.74 HV0.2) and elastic modulus (269.06 GPa), respectively. The interfacial friction coefficient (0.343–0.444) was significantly reduced compared to the surface friction coefficient (0.562–0.617). Wear track analysis revealed that the width in the cladding layer-to-substrate transition zone (CTSZ) was 22.1–43.2% wider than that in the substrate-to-cladding layer transition zone (STCZ). This disparity is attributed to stress concentration induced by the abrupt hardness change across the CTSZ, promoting the formation of a three-tiered step structure (with a step height difference of 2.1–4.1 µm). In contrast, the progressive hardness series in the STCZ facilitated a smoother wear surface. The dominant wear mechanism was identified as a combination of abrasive and oxidative wear. This study provides a theoretical foundation for optimizing such high-reliability components. Full article

Among various H₂ production methods, splitting water using renewable electricity for H₂ production is regarded as a promising approach due to its high efficiency and zero carbon emissions. The oxygen evolution reaction (OER) is an important part of splitting water, but also the main bottleneck. The anodic oxygen evolution reaction (OER) for water electrolysis technology involves multi-electron/proton transfer and has sluggish reaction kinetics, which is the key obstacle to the overall efficiency of electrolyzing water. Therefore, it is necessary to develop highly efficient and cheap OER electrocatalysts to drive overall water splitting. Herein, a series of efficient RuO₂-Co₃O₄ composites were synthesized via a straightforward three-step process comprising solvothermal synthesis, ion exchange, and calcination. The results indicate that using 10 mg of RuCl₃·xH₂O and 15 mg of Co-MOF precursor in the second ion exchange step is the most effective way to acquire the Co₃O₄-RuO₂-10 (RCO-10) composite with the largest specific area and the best electrocatalytic performance after the calcination process. The optimal Co₃O₄-RuO₂-10 composite powder catalyst displays low overpotential (η₁₀ = 272 mV), a small Tafel slope (64.64 mV dec⁻¹), and good electrochemical stability in alkaline electrolyte; the overall performance of Co₃O₄-RuO₂-10 surpasses that of many related cobalt-based oxide catalysts. Furthermore, through integration with a carbon cloth substrate, Co₃O₄-RuO₂-10/CC can be directly used as a self-supporting electrode with high stability. This work presents a straightforward method to design Co₃O₄-RuO₂ composite array catalysts for high-performance electrocatalytic OER performance. Full article

Background: Metabolic syndrome (MS) and obstructive sleep apnea (OSA) frequently coexist, exacerbating systemic inflammation, oxidative stress, and metabolic dysregulation. This study evaluates the effects of dietary and probiotic interventions, compared to a non-intervention control group, on metabolic, hemodynamic, and neurochemical parameters, with a specific focus on the neurotransmitters GABA and glutamate. Methods: In a prospective randomized study (2020–2023), 120 patients with coexisting MS and OSA were assigned to three groups: control (n = 36), diet therapy (n = 42), and diet therapy combined with probiotics (n = 42). Interventions lasted six months and included personalized dietary plans and probiotic supplementation. Outcome measures included BMI, visceral fat, HOMA index, lipid profile, oxygen saturation, and urinary GABA and glutamate levels. Unsupervised K-means clustering and principal component analysis (PCA) were applied to identify phenotypic response patterns based on delta values. Results: Diet therapy led to significant reductions in BMI (−15.7%, p = 0.001), visceral fat (−17.3%, p = 0.001), triglycerides (−14.6%, p = 0.003), uric acid (−9.5%, p = 0.011), and C-reactive protein (CRP) (−21.4%, p = 0.007). The combined intervention group exhibited further improvements in visceral fat (−22.8%, p = 0.001), glutamate (−18.2%, p = 0.002), and GABA levels (+19.5%, p = 0.001). Oxygen saturation improved across all groups, with the greatest increase in the probiotics group (+2.3%). Clustering analysis revealed three distinct response phenotypes—strong, moderate, and non-responders—highlighting inter-individual variability in treatment efficacy. Conclusions: Personalized dietary interventions, especially when paired with probiotics, effectively improve metabolic, inflammatory, and neurochemical profiles in patients with MS and OSA. Integrating clustering algorithms enables phenotype-specific stratification, offering a step toward precision lifestyle medicine. Future studies should explore long-term outcomes and refine microbiota-targeted approaches to optimize intervention efficacy. Full article