Search Results (17,008)

The development of efficient, low-cost hydrodeoxygenation (HDO) catalysts is essential for converting renewable lipids into sustainable aviation fuels. Here, we report a series of sulfided bimetallic NiFe/γ-Al₂O₃ catalysts and systematically investigate the promotional role of Fe in the HDO of methyl decanoate, a model lipid compound. Using complementary characterization together with fixed-bed reactor kinetic measurements, we elucidate the influence of the Ni/Fe ratio on catalyst structure, sulfidation behavior, electronic properties, and reaction pathway. Fe incorporation promotes Ni sulfidation and induces electron transfer from Fe to Ni, as directly evidenced by a red shift in the CO stretching frequency (from 2094 cm⁻¹ for Ni-only to 2090 cm⁻¹ for NiFe), indicating increased electron density on Ni sites and enhanced π-backdonation. Among the catalysts tested, N5F5 (Ni/Fe mass ratio = 1:1) exhibits the highest Ni sulfidation degree, the highest turnover frequency (32.1 h⁻¹), and the lowest apparent activation energy (E_a ≈ 92 kJ/mol). At 360 °C, it achieves 52.9% methyl decanoate conversion, far exceeding that of monometallic Ni and Fe catalysts. Product selectivity analysis reveals that sulfided Ni sites predominantly promote the decarboxylation/decarbonylation (DCOx) pathway, whereas Fe sites contribute only marginally to direct deoxygenation (DDO). This work provides the first direct spectroscopic evidence for Fe-to-Ni electron transfer in sulfided NiFe catalysts and establishes a clear structure-performance correlation, offering a rational design strategy for low-cost, high-performance HDO catalysts for lipid upgrading. Full article

Heavy metal (HM) contamination near mining operations in Kazakhstan poses a serious threat to the environment. However, data on the state of chernozem soils in this region is limited. This study assessed the bioaccumulation of HMs and translocation within the soil–sunflower (Helianthus annuus L.) system in a southern Calcic Chernozem in the Kostanay region (Northern Kazakhstan), which is located 50 km from the nearest mining facility. The content of seven HMs (Cd, Co, Cr, Cu, Ni, Pb, and Zn) and arsenic (As), as well as five macroelements (K, Ca, S, Mg, and P), was determined in 18 soil samples from the complete soil pedon (0–150 cm) and in eight anatomical parts of six sunflower plants at physiological maturity. Most metals exhibited a deficiency relative to upper continental crustal Clarke values (Clarke of Concentration (CC) < 1 for Cr, Cu, Ni, Pb, and Zn), with a moderate lithogenic anomaly for Cd (CC = 1.65–3.57) and a localized Co anomaly in the Bk horizon (56.26 mg kg⁻¹), indicating no pronounced HM contamination at the investigated agricultural site. Metal distribution exhibited strong organ specificity in sunflower plants. Cd, Cu, and Zn accumulated preferentially in the leaves, whereas Ni and Co were more concentrated in the seeds and stems, respectively. Only cadmium exceeded the threshold values for both BCF > 1 (1.01) and TF > 1 (1.47), confirming the status of sunflower as a cadmium accumulator. These results provide a preliminary reference dataset of the organ-specific distribution of heavy metals in H. annuus L. plants, which can serve as a local baseline for sunflower growth in uncontaminated southern Chernozems. This information can contribute to future environmental monitoring purposes in the region, acting as an exploratory benchmark. Full article

Maintaining effective fluid-loss control in water-based drilling fluids under coupled high-salinity, high-temperature, and high-density conditions remains a critical challenge in deep and ultra-deep drilling operations. In this study, a low-molecular-weight polymer fluid-loss additive (LM-ASQF) was synthesized via redox-initiated copolymerization of acrylamide, dimethyldiallylammonium chloride, and sodium allyl sulfonate. The synthesis route and proposed polymer structure were further illustrated to clarify the incorporation of amide, quaternary ammonium, and sulfonate functional units within the LM-ASQF molecular architecture. The polymer exhibited a controllable number-average molecular weight of 18.2–29.4 kDa with a unimodal distribution. Thermal analysis confirmed that no main-chain-dominated degradation occurred below 220 °C, indicating structural stability under high-temperature conditions. In drilling-fluid systems containing NaCl, CaCl₂, and mixed salts (0–20%), LM-ASQF maintained stable rheological properties, with apparent viscosity ranging from 26.1 to 41.6 mPa·s, while the API fluid loss was controlled within 5.8–11.2 mL. After thermal aging at 220 °C for 16 h, the API fluid loss remained below 13 mL in both freshwater and mixed-salt systems. In high-density systems (1.80–2.40 g/cm³), the drilling fluids preserved continuous rheological structures and showed no abrupt increase in filtration. Mechanistically, fluid-loss control was primarily attributed to synergistic interfacial adsorption of amide groups, hydration stabilization induced by sulfonate functionalities, and particle rearrangement-driven filter-cake densification, rather than viscosity enhancement through long-chain entanglement. This mechanism enables effective filtration control without excessive viscosity increase, thereby maintaining rheological compatibility under complex conditions. These results demonstrate that the low-molecular-weight design strategy provides a reliable approach for achieving stable fluid-loss control in water-based drilling fluids under high salinity, elevated temperature, and high-density conditions. Full article

Indium-addition synthesis of a misfit layered compound (SnSe)_1.16(NbSe₂) was found to obtain a novel sample (In-sample) with another stacking structure in (SnSe)_1.16(NbSe₂), causing the increase in the superconducting transition temperature T_c and the in-plane upper critical field μ₀$H_{\mathrm{c}2}^{\mathrm{in}-\mathrm{plane}}$ (0). Crystal structure analysis using single crystals revealed that the In-sample has a significantly elongated lattice constant along the c axis due to thickening of the layer other than the NbSe₂, while retaining the original misfit layered structure. The T_c increased from 3.6 K to 5.4 K in the In-sample. Furthermore, the in-plane upper critical fields μ₀$H_{\mathrm{c}2}^{\mathrm{in}-\mathrm{plane}}$ (0) exceeded the Pauli limit μ₀H_p, reaching 29.4 T (μ₀H_p ~ 10 T). The coherence length along the c axis was reduced in the In-sample, indicating enhanced two-dimensionality. These results suggest that the In-sample not only has another stacking structure but also exhibits higher T_c and μ₀H_c2. Full article

Background/Objectives: Drug repurposing has emerged as a promising strategy for identifying novel anticancer agents among clinically established drugs. Fexofenadine, a second-generation H1 antihistamine, has been proposed as a candidate for repurposing in oncology; however, the molecular mechanisms underlying its biological activity remain insufficiently characterized. This study investigated the effects of fexofenadine on oxidative stress, mitochondrial function, apoptosis, and pro-survival signaling pathways in cervical and lung cancer cells. Methods: HeLa and A549 cancer cells, as well as non-tumorigenic Beas-2B epithelial cells, were exposed to fexofenadine under in vitro conditions. Cell viability, apoptosis, reactive oxygen species generation, mitochondrial membrane potential, DNA damage, autophagy-associated responses, and PI3K/AKT and MAPK/ERK pathway activation were assessed using flow cytometry, fluorescence microscopy, electron microscopy, and biochemical assays. Three-dimensional spheroid cultures and N-acetyl-L-cysteine rescue experiments were additionally employed to evaluate biological relevance and the contribution of oxidative stress. Results: Fexofenadine induced concentration-dependent accumulation of reactive oxygen species, mitochondrial membrane depolarization, Bcl-2 inactivation, caspase-3/7 activation, DNA damage, and apoptotic cell death in HeLa and A549 cells. Antioxidant pretreatment with N-acetyl-L-cysteine significantly reduced oxidative stress, attenuated mitochondrial dysfunction, and partially suppressed apoptosis. Fexofenadine was associated with reduced PI3K/AKT and MAPK/ERK pathway activation and promoted autophagy-associated responses. In three-dimensional spheroid cultures, treatment disrupted spheroid integrity and increased apoptotic cell death. Non-tumorigenic Beas-2B cells exhibited lower sensitivity to treatment than malignant cells. Conclusions: Fexofenadine disrupts redox homeostasis and is associated with reduced activation of pro-survival signaling pathways, resulting in oxidative stress-associated mitochondrial dysfunction and apoptosis in cancer cells. These findings provide mechanistic support for further evaluation of fexofenadine as a candidate for anticancer drug repurposing, while additional pharmacokinetic and in vivo studies are required to determine its translational relevance. Full article

Hydrolysis of cellulose to produce ethanol has become an effective way to utilize biological resources, but its large-scale industrial application has been limited. In this study, a one-pot catalytic conversion process for transforming cellulose into ethanol was developed. Meanwhile, multifunctional Mo/Pt/WO_x/Al₂O₃ catalysts were prepared by loading nano-alumina (Nano-Al₂O₃) via a stepwise impregnation method. The influence of catalysts with varying metal ratios on the types of products generated during the cellulose hydrolysis process to ethanol was examined. The catalyst with 0.1% Mo, 2% Pt, and 7.5% W loadings showed the best selectivity. With an ethanol yield of 45.3% after heating at 5 MPa H₂ and 518 K for 2 h. Nano-Al₂O₃ can provide suitable active sites. The addition of W⁵⁺ and Mo⁰ increased the surface oxygen vacancy density and enhanced the hydrodeoxidation and metal anchoring capacity of the catalyst. The solid solution structure facilitates electron transfer from W and Mo atoms to Pt atoms, forming electron-rich Pt^δ- species, promoting the hydrolysis of cellulose and the formation of ethanol. Full article

The increasing contamination of municipal wastewater by a broad spectrum of pharmaceuticals necessitates effective quaternary treatment stages. This pilot study evaluates an innovative combined technology: physical electrostatic pretreatment (conducted using experimental equipment based on a patented design (EP 2388068)) followed by biodegradation in real secondary effluent samples (COD_(Cr) 22.0 mg·L⁻¹ to 32.0 mg·L⁻¹). A total of 17 selected micropollutants were subjected to an 8-h exposure in a high-intensity electrostatic field (20 kV) and a subsequent 20-day microbial degradation using a mixed culture of erythropolis, R. rhodochrous, and R. degradans. Results demonstrate high substance-specific efficiency. The most significant synergistic effect was observed for moderately biodegradable compounds, particularly venlafaxine (improvement up to ~44%), trimethoprim (25–36%), and tramadol (31–58%), representing a ~30–37% efficiency increase over standalone biodegradation. For readily biodegradable (e.g., metoprolol) or highly persistent substances, the impact was inconsistent. Physical pretreatment alone at 20 kV exhibited low to moderate efficiency (up to ~30%) without the biological stage. This combined approach represents a promising synergistic solution for wastewater treatment plant intensification. The primary mechanism involves enhancement of target compound bioavailability induced by the electrostatic field, which subsequently accelerates microbial metabolism. Full article

This study presents a comparative evaluation of geopolymer foams incorporating either commercially available shape-stabilized phase change materials (PCMs) or laboratory-developed diatomite–paraffin PCM granules with controlled particle size fractions ranging from <1.6 mm to >2.5 mm. All PCM variants were incorporated at a constant dosage of 7.5 wt.% to isolate the influence of PCM type on the properties of the resulting composites. The commercial materials comprised PX-4, PX15, and PX20 (Rubitherm Technologies GmbH), whereas the laboratory-developed PCM consisted of paraffin immobilized within a porous diatomite matrix to produce granular shape-stabilized composites. The experimental program included the determination of bulk density, total porosity, pore size distribution, thermal conductivity (λ), thermal resistance (R), specific heat capacity (Cp), and compressive strength. The pore structure was characterized by mercury intrusion porosimetry (MIP), while the morphology and dispersion of PCM particles within the geopolymer matrix were investigated using scanning electron microscopy (SEM). All mixtures were produced using the same alkali-activated matrix and identical curing conditions, with the PCM content maintained at 7.5 wt.%. The results demonstrated that the type of PCM significantly affected the microstructure and thermophysical performance of the geopolymer foams. The laboratory-developed diatomite–paraffin PCM provided the most favorable thermal insulation performance, exhibiting the lowest thermal conductivity (0.095 W/m·K) together with the highest thermal resistance (0.278 m²·K/W). In contrast, the commercial PX15 and PX20 materials exhibited the highest specific heat capacities (1.740 and 1.778 kJ/kg·K, respectively), indicating superior thermal energy storage capability. In addition, the estimated production cost of the laboratory-developed PCM (2.5–4.0 EUR/kg) was substantially lower than that of the commercial PX materials (approximately 20 EUR/kg), highlighting its potential as a cost-effective alternative for sustainable, energy-efficient building materials. These findings demonstrate that both commercial and laboratory-developed PCM systems can effectively enhance the functionality of geopolymer foams, although they provide different balances between thermal insulation, heat storage capacity, and production cost. Full article

In this work, charge characteristics of submicron heterogeneities (SMH) spontaneously formed in aqueous solutions of various biomolecules: seven amino acids of various types (nonpolar glycine, polar serine, hydrophobic valine, aromatic phenylalanine, sulfur-containing methionine, glutamic acid and basic arginine), ATP, monosaccharide glucose and disaccharide sucrose were studied. The isoelectric points of the SMH in the amino acid solutions determined turned out to be in the pH range from 2.4 to 4, being shifted to the acidic region relative to the isoelectric points of the amino acids themselves (except for glutamic acid). The zeta potential of the SMH was measured in solutions of all the biomolecules under conditions close to the intracellular environment at pH = 7 and basic K⁺ ion content 150 mM. The zeta potential appeared to be negative in all cases. Using these values of the zeta potential, the concentration of OH-anions inside the SMH was estimated, and the pH values corresponding to this concentration turned out to be in the range of 7–10. Since the cell cytosol is an aqueous solution of various biomolecules, SMH must also form inside cells. An analogy is drawn between SMH and membraneless organelles, many of which have been discovered recently. The presence of compact regions with alkaline pH inside the cell is a fundamentally new factor in cell biology, which may have important consequences. Full article

Background/Objectives: The increasing prevalence of antimicrobial resistance has become a major challenge in the management of Helicobacter pylori infection and is a leading cause of eradication failure. Resistance to clarithromycin and fluoroquinolones is primarily mediated by mutations in the 23S rRNA and gyrA genes, respectively. This study aimed to evaluate the prevalence of resistance-associated mutations in the 23S rRNA and gyrA genes, investigate their relationship with phenotypic antimicrobial resistance, assess their impact on eradication outcomes, and develop a prediction model for treatment failure. Methods: This retrospective real-world cohort study included 294 adult patients with confirmed H. pylori infection evaluated at the Oradea County Emergency Clinical Hospital, Romania, between November 2022 and November 2025. Clinical, endoscopic, histopathological, microbiological, molecular, and treatment outcome data were collected from medical records. Resistance-associated mutations in the 23S rRNA (A2143G, A2142G, and A2142C) and gyrA (N87K, D91G, and D91N) genes were analyzed and correlated with phenotypic antimicrobial resistance and eradication outcomes. Independent predictors of eradication failure were identified using multivariable logistic regression, and a prediction model was subsequently developed. Results: Overall, 101 patients (34.4%) harbored 23S rRNA mutations and 64 (21.8%) carried gyrA mutations, while 27 patients (9.2%) exhibited mutations in both genes. A2143G was the most frequent mutation (25.2%). Resistance-associated mutations showed strong concordance with phenotypic antimicrobial resistance. Patients with wild-type strains achieved eradication rates exceeding 90%, whereas significantly lower success rates were observed among patients carrying A2143G, A2142G, or gyrA mutations. Multivariable analysis identified previous eradication attempts (aOR 3.12, 95% CI 1.71–5.68), A2143G mutation (aOR 4.86, 95% CI 2.43–9.72), gyrA mutation (aOR 2.91, 95% CI 1.45–5.84), increasing age (aOR 1.03, 95% CI 1.01–1.05), and treatment with clarithromycin-based triple therapy (aOR 2.18, 95% CI 1.02–4.63) as independent predictors of eradication failure. The prediction model demonstrated excellent discriminatory performance (AUC 0.88, 95% CI 0.84–0.92), with a sensitivity of 82.5%, specificity of 80.1%, and satisfactory calibration (Hosmer–Lemeshow p = 0.68). Conclusions: Resistance-associated mutations in the 23S rRNA and gyrA genes are strongly associated with phenotypic antimicrobial resistance and reduced H. pylori eradication success. Molecular resistance testing may facilitate individualized treatment selection and improve clinical outcomes. The proposed prediction model, integrating clinical characteristics, treatment regimen, and molecular resistance markers, demonstrated excellent performance and may represent a useful tool for identifying patients at increased risk of eradication failure. Full article

Background/Objectives: Parkinson’s disease (PD) exhibits marked sexual dimorphism, with a higher incidence and earlier onset in men than in women. However, the impact of biological sex on systemic molecular alterations in PD remains poorly understood. This pilot study aimed to identify sex-specific circulating signatures associated with PD. Methods: Serum samples from a selected cohort of PD patients and healthy controls (HC) of both sexes were analyzed using an integrated biochemical and ¹H NMR-based metabolomic approach. Oxidative stress markers, antioxidant proteins, inflammatory mediators, matrix metalloproteinases, α-synuclein species, and circulating antibodies were evaluated. Results: This analysis indicated that, while global oxidative stress markers were unchanged, sex-related differences in antioxidant pathways were observed as suggested by the reduced Nrf2 expression observed in PD females and increased IL-6 levels, above all in male PD patients. MMP3 levels were significantly higher in female PD patients compared with males. Male patients showed higher levels of 52 kDa protease-resistant α-synuclein species, while females exhibited increased antibody titers against both monomeric and aggregated forms. Metabolomic profiling suggested a disease-associated metabolic remodeling in PD, with distinct sex-related metabolic signatures and a more pronounced and widespread metabolic dysregulation in males. Conclusions: These findings suggest that biological sex may contribute to systemic molecular heterogeneity in PD, with trends indicating more pronounced inflammatory and metabolic alterations in males and distinct immune-related responses in females. Given the exploratory nature of the study and the limited sample size, these observations should be interpreted cautiously and require validation in larger, independent cohorts. Nevertheless, the results support the importance of considering sex-related molecular differences in future biomarker studies and precision medicine approaches for PD. Full article

Post-disaster scenarios such as tsunamis require rapid terrain assessment that cannot wait for the next satellite synthetic aperture radar (SAR) revisit, yet a readily deployable system remains lacking. We present an off-the-shelf K-band drone-borne dual circular polarimetric (DCP) SAR and a processing pipeline for on-demand terrain classification. Compared with fully polarimetric (FP) SAR, DCP requires only a single transmit polarization and two receive channels, providing a wider swath than FP for the same acquisition, while still separating odd-bounce and even-bounce scattering mechanisms, which dual linear polarimetric modes with the same channel count provide with greater ambiguity due to their sensitivity to target orientation angle. To compensate for platform motion, we implemented RTK global navigation satellite system (GNSS) guided time-domain backprojection (TDBP) with phase gradient autofocus (PGA), yielding an 11.98 dB improvement in peak amplitude. We then applied single-target wire calibration to correct a measured 8.91 dB inter-channel complex gain difference between co-polarization and cross-polarization. As a result, H/α decomposition of the calibrated DCP data classifies canonical reflectors, artificial structures, gravel roads, vegetation, and a pond surface. These field experiments extend compact polarimetric H/α decomposition to drone-borne SAR data for terrain discrimination, establishing a practical pathway toward rapid post-disaster terrain assessment. Full article

Background/Objectives: Malignant melanoma is characterized by constitutive PI3K/Akt/mTOR and MAPK activation, driving aggressive behavior and therapeutic resistance. Alpha-lipoic acid (αLA), a naturally occurring dithiol compound with an established clinical safety profile, has shown anticancer potential; however, its integrated molecular mechanisms in melanoma remain poorly defined. This study aimed to comprehensively evaluate the cytotoxic and mechanistic effects of αLA in B16F10 murine melanoma cells. Methods: Antiproliferative effects were assessed by MTT assay at four concentrations (250, 500, 750, 1000 µM) over 48 h. Protein levels of apoptotic markers (Bax, Bcl-2, Caspase-3, AIF), kinase signaling components (p-Akt, p-mTOR, p-ERK, p-JNK), ER stress markers (GRP78, GADD153/CHOP), and cell cycle regulator Wee1 were quantified by ELISA at a specifically selected sub-lethal concentration of 750 µM (inducing ~38% growth inhibition). Results: αLA dose-dependently inhibited B16F10 proliferation. At 750 µM, it triggered robust intrinsic apoptotic signaling, evidenced by a nearly 10-fold shift in the Bax/Bcl-2 ratio and greater than 9-fold Caspase-3 activation. Elevated AIF suggested profound mitochondrial stress and the potential priming of concurrent caspase-independent cell death mechanisms. αLA suppressed survival signaling by reducing p-Akt (44%), p-mTOR, p-ERK, and p-JNK. Treatment triggered lethal ER stress via GRP78 and GADD153/CHOP upregulation and upregulated Wee1, suggesting the induction of stress-responsive checkpoint signaling. The simultaneous CHOP upregulation and p-Akt suppression highlight a concurrent dysregulation of stress and survival pathways, suggesting a potential pro-apoptotic interplay. Conclusions: αLA exerts potent multi-target anticancer effects by inducing a broad spectrum of associated molecular changes, including the suppression of PI3K/Akt/mTOR and MAPK networks, induction of ER stress, engagement of cell cycle checkpoints, and activation of the mitochondrial Bax/Bcl-2/Caspase-3 axis. Importantly, these correlative findings do not establish proven pathway dependencies. Nevertheless, this concurrent dysregulation positions αLA as a potential disruptor of inter-pathway resilience underlying drug resistance. Full article

Polypropylene (PP) waste, including microplastic debris, motivates molecular-scale studies of the intrinsic factors governing thermal degradation. In this work, the bond dissociation energies (BDEs) of C–C and C–H bonds were systematically evaluated in a finite isotactic polypropylene oligomer containing fifteen propylene repeat units, (–C₃H₆–)₁₅, using Density Functional Theory at the M06-2X/LANL2DZ level. Thermochemical corrections were evaluated at 873.15 K, a temperature relevant to pyrolysis studies. Within the selected oligomer model, C–C bonds exhibited lower BDE values (82.28–87.41 kcal·mol⁻¹) than C–H bonds (90.18–104.93 kcal·mol⁻¹), indicating a thermochemical preference for backbone scission. The lowest calculated BDE values were associated with specific tertiary carbon environments, including sites C24 and C28. A mixed-effects model identified bond type and carbon type as the principal factors associated with BDE variation, while principal component analysis summarized the covariation among the electronic and thermodynamic descriptors. These results provide a molecular-scale description of intrinsic scission tendencies within the selected PP oligomer and establish a basis for subsequent kinetic, catalytic, and experimental studies. Full article

Microalgal lipid extraction, particularly the subsequent solvent recovery phase, constitutes the primary energy bottleneck in algal-based biodiesel biorefineries. Recently, switchable polarity solvents (SPS), such as the tertiary amine N,N-dimethylcyclohexylamine (DMCHA), have emerged as promising ‘green’ alternatives capable of extracting lipids directly from wet biomass, theoretically bypassing energy-intensive drying and solvent recovery distillation stages. This study presents a rigorous techno-energetic and thermodynamic evaluation combined with supporting experiments for qualitative conclusions to scrutinize the actual viability of DMCHA-mediated extraction against conventional hexane benchmarks, across three process configurations using different biomass types: algal liquor, wet paste, and dried biomass. Contrary to widespread assumptions in the literature, fundamental thermodynamic calculations reveal that the energy required for amine regeneration via protonation/deprotonation mechanisms equals or exceeds that of conventional distillation. Furthermore, mitigating biomass drying inadvertently escalates overall downstream energy and economic penalties due to the excessive solvent volumes demanded by dilute aqueous matrices. Direct extraction from algal liquor displays a cost and energy consumption countably higher than the other scenario; precisely, a cost of 232 €/kg of lipids and energy consumption of 454 kWh/kg of lipids. Extraction from wet paste exhibits, indeed, a slightly lower energy consumption compared to the hexane process (respectively 51 kWh/h versus 72 kWh/kg), but, due to the CO₂ requirements, the cost is double (19 €/kg of lipids versus 8 €/kg of lipids). Ultimately, while switchable polarity chemistry offers a marginal reduction in process water footprints, it introduces substantial operational complexity, elevated carbon dioxide payloads, and severe solvent degradation risks, challenging its current readiness for industrial upscaling. Full article