Search Results (12,301)

In this paper, the regenerated NdFeB magnets were fabricated by Nd₈₅Al₁₅ alloy diffusion, and the influence of alloy content and diffusion temperature on the properties and microstructure was systematically studied. The recovery mechanism of magnetic properties was discussed based on the analyses using scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and electron probe microanalysis (EPMA) observation. The results indicate that the coercivity (H_cj) increases significantly with both alloy addition and temperature, reaching the maximum value of 1087 kA/m (80.9% enhancement) compared with the non-diffused magnet (601 kA/m). The maximum remanence (B_r) and maximum energy product (BH_max) of the diffused magnet are 0.99 T and 184.7 kJ/m³, which are 8.8% and 5.9% lower than those (1.085 T and 196.3 kJ/m³) of the non-diffused magnet. The density and compressive strength of the diffused magnet are enhanced by 8.2% (7.25 g/cm³) and 67.47% (628 MPa), respectively. As the compensation of Nd₈₅Al₁₅ melt, the density, B_r and BH_max are improved via the liquid filling into pores. Simultaneously, the H_cj is enhanced through the repair of grain boundary defects and the formation of continuous Nd-rich phases. Full article

Traditionally, Lasiocephalus ovatus Schltdl. (Asteraceae) has been used as an aromatic medicinal plant, particularly in the treatment of kidney-related ailments. However, scientific evidence validating its chemical composition and bioactivity remains limited. According to our literature search, there are no previous studies on the in vitro antibacterial, antioxidant, or anti-inflammatory activities of the essential oil from the aerial parts of Lasiocephalus ovatus; therefore, this study provides the first experimental evidence of these biological activities for this species. An essential oil (EO) was steam-distilled from the aerial parts of L. ovatus, grown at 4410 m above sea level in the paramos of Chimborazo Province (Ecuador), and subsequently analyzed. The distillation yield was 0.21% (w/w) based on dry plant material. Gas chromatography was employed for qualitative (GC-MS) and quantitative (GC-FID) analyses, using two different capillary columns, coated with 5% phenyl methyl polysiloxane (non-polar) and polyethylene glycol (polar) stationary phases. Dual stationary phases were required to provide complementary selectivity, which reinforced the identification and quantification of compounds. The major components of the EO were silphinene (3.4–3.5%), δ-selinene (3.6–3.1%), β-cyclogermacrene (18.7–18.1%), kessane (4.5–4.2%), spathulenol (13.3–13.3%), viridiflorol (3.1–3.0%) and neophytadiene (4.8–4.4%), values referred to the non-polar and polar phase respectively. The enantioselective analysis revealed that (1S,5S)-(−)-α-pinene, (1S,5S)-(+)-β-pinene and (R)-(−)-α-phellandrene were enantiomerically pure, whereas germacrene D was present as a scalemic mixture. The essential oil of L. ovatus exhibited a minimum inhibitory concentration (MIC) of 250 µg/mL against Staphylococcus aureus and 500 µg/mL against Escherichia coli. Its antibacterial activity is likely associated with the presence of bioactive sesquiterpenes such as silphinene, δ-selinene, and spathulenol, which are known for their membrane-disruptive properties. Regarding its antioxidant potential, the observed moderate radical scavenging activity (SC₅₀ = of 375.7 µg/mL) can be attributed to its complex mixture, particularly to oxygenated terpenoids like viridiflorol and spathulenol, which are recognized for their radical-neutralizing capacity. In the anti-inflammatory assay, the EO’s moderate potency (IC₅₀ = 165.29 ± 4.75 μg/mL) is also consistent with the anti-inflammatory profile reported for several of its major constituents, including spathulenol and viridiflorol. While significantly lower than that of aspirin (28.85 ± 7.66 μg/mL), this bioactivity is considerable within the context of a plant extract. Overall, the antibacterial, antioxidant, and anti-inflammatory effects are consistent with the EO’s terpene-rich composition, particularly oxygenated sesquiterpenes, while the enantiomeric distribution of chiral monoterpenes may further modulate bioactivity; consequently, future studies should include enantioselective quantification, broader antioxidant assays (e.g., ABTS, FRAP, ORAC, CUPRAC), cytotoxicity at active concentrations, and mechanistic and in vivo validation. Full article

Background: Antimicrobial resistance is one of the major challenges in healthcare, leading to more severe infections, higher mortality, and increased healthcare costs. Therefore, exploring new alternatives, such as plant extracts with antimicrobial properties helps to reduce bacterial resistance. Artemisia annua L., Hibiscus sabdariffa L., and Paronychia argentea Lam. are traditionally used for their biological properties, including antimicrobial activity. However, scientific evidence regarding their antibacterial effects against clinically important bacteria remains limited. Methods: Extracts were obtained from the mentioned plants and phytochemically characterized by GC/MS. Phytochemical analysis revealed the presence of fatty acids, phenolic compounds, aliphatic compounds, and terpenoids. Antibacterial activity was evaluated using the diffusion method with a modified Kirby-Bauer technique and the microdilution method employing the massive plate sealing drop approach. Results: All extracts exhibited bacterial inhibition, with H. sabdariffa L. showing the strongest activity against E. coli (256 mg/mL), K. pneumoniae (256 mg/mL), P. aeruginosa (128 mg/mL), Salmonella sp. (128 mg/mL), and S. aureus (64 mg/mL). Conclusions: Hydroethanolic extracts of A. annua L., H. sabdariffa L., and P. argentea Lam. exhibit antibacterial activity against clinically relevant bacteria and represent promising candidates for future preclinical studies. Full article

Table grapes are commonly consumed fresh, and their market value is largely determined by ripeness, grape color, mineral composition, and variety-specific aroma. This study integrated physicochemical ripening indicators (°Brix%, pH, titratable acidity, maturity index), CIELAB color parameters measured on the outer skin and inner sections, multi-element mineral profiling following microwave-assisted digestion (ICP-MS), and volatile organic compound (VOC) profile by HS-SPME/GC-MS to characterize five table grape varieties (Thompson Seedless, Isabella, Mevlana, Pepita Alfonso, and Red Globe). Significant differences in ripeness were found among the varieties (p < 0.01). Isabella had the highest soluble solids content (22.91 °Brix%), while Pepita Alfonso had the highest maturity index (79.89) and the lowest titratable acidity (0.22%). Color measurements also showed significant differences among the varieties (p < 0.01). Thompson Seedless exhibited the highest peel lightness/yellowness and chroma values, while Pepita Alfonso and Red Globe had a darker, lower chroma profile. Color index values differed between the peel and the inner cross-section depending on the variety (p < 0.01). Mineral composition was found to be variety-specific (p < 0.01). The dominant macroelements among the samples were K, P, and Mg, and statistically significant differences were also determined in trace elements (p < 0.01). A total of 42 volatile organic compounds (VOCs) were identified. Aldehydes were dominant in the volatile fraction (39.07–64.96%), nonanal contributed a significant percentage, and terpenoids (floral aroma note) were found in the highest percentage in the Isabella variety (28.87%). PCA applied to the integrated physicochemical, color, and mineral dataset enabled the clear discrimination of the five table grape cultivars. Pepita Alfonso was positioned toward positive PC2, and Red Globe occupied the opposite segment. Thompson Seedless and Isabella were separated mainly along PC1, while Mevlana showed an intermediate profile. SIMCA class-distance results confirmed the visual separation. All pairwise interclass distances were above the decision threshold (ICD > 3), ranging from 62,922 (Red Globe–Mevlana) to 806,425 (Isabella–Pepita Alfonso). Findings indicated robust cultivar-level classification for authenticity and quality control purposes. Overall, the integrated multi-domain approach is considered to provide a solid foundation for variety differentiation and quality-oriented harvesting and market management. Full article

We evaluated the effect of ammonium sulfate, a major component of airborne particulate matter, in the quantification of airborne micro- and nanoplastics (AMNPs) by analytical pyrolysis–gas chromatography-mass spectrometry (Py-GC/MS). Analytical pyrolysis has shown promising potential in providing mass-based information on AMNPs, which are compatible with established standard protocols to monitor airborne particulate matter. Py-GC/MS can be performed with little to no sample preparation, minimizing the risk of polymer loss or sample contamination. However, reactive components of particulate matter, such as inorganic salts, can interfere with the Py-GC/MS measurement of polymers, leading to over/underestimation of the polymer content and instrument contamination. In this study, we have shown that ammonium sulfate can generate matrix interference in the quantification of AMNPs in PM_2.5. We have provided a solution to this issue based on water rinsing of the particulate matter directly inside the pyrolysis crucible, avoiding sample loss and preventing instrument contamination. Full article

Lightweight artificial aggregates (LWAs) are key materials for sustainable construction, offering reduced structural self-weight, improved thermal performance, and enhanced resource efficiency. However, their production remains geographically concentrated and largely dependent on virgin raw materials, while significant volumes of industrial waste continue to be landfilled. This study addresses these challenges by developing regional LWAs through the incorporation of high levels of porcelain polishing residue (PPR) into red clay matrices, promoting waste valorisation within a circular economy framework. Four mixtures were produced with 20, 40, 60, and 80 wt.% PPR replacing red clay and sintered at 1220 °C and 1240 °C. Raw materials were characterized by laser granulometry, X-ray fluorescence, and X-ray diffraction, while the produced aggregates were evaluated in terms of bloating index, mass loss, bulk density, water absorption, modulus of deformation, crushing strength, and visual morphology. A full factorial experimental design coupled with analysis of variance (ANOVA) was applied to quantify the effects of mixture composition, firing temperature, and aggregate size. All formulations exhibited significant bloating (>35%), with expansion intensifying as PPR content and firing temperature increased, reaching up to 140.6% for mixtures with 80% PPR at 1240 °C. Bulk density values ranged from 0.53 to 1.14 g/cm³, and water absorption remained below 20% for all compositions, confirming their classification as lightweight aggregates. Mechanical performance was strongly dependent on the balance between expansion and matrix densification. The mixture containing 40% red clay and 60% PPR sintered at 1220 °C showed the most favourable performance, achieving crushing strengths of approximately 5.00 MPa while maintaining low density, outperforming commercial reference aggregates. Statistical analysis identified mixture composition and firing temperature as the dominant factors governing expansion and density. The results demonstrate that porcelain polishing residue is a technically viable and sustainable raw material for high-performance LWA production, enabling regional manufacturing routes with reduced environmental impact and strong potential for structural and non-structural construction applications. Full article

Background/Objectives: The COVID-19 pandemic has emphasized the urgent need for non-invasive diagnostic strategies. While breath analysis has been widely investigated, sweat and sebum remain largely unexplored, despite being abundant, chemically diverse, and easily collected. This exploratory study presents a proof-of-concept workflow to evaluate their potential for infection biomarker discovery. Methods: Samples from 51 subjects were analyzed by headspace solid-phase microextraction coupled with gas chromatography and time-of-flight mass spectrometry (HS-SPME-GC/ToF-MS). Over 8000 untargeted volatile compounds were detected, reflecting the high complexity of these matrices. Results: Data refinement and chemometric modelling using principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) revealed robust separation between SARS-CoV-2-positive Patients and Controls. Classification accuracies consistently exceeded 95%, demonstrating the robust discriminative performance of the approach. Among the detected volatiles, 2-methylbenzenemethanol acetate emerged as the most informative compound, representing a potential biomarker candidate. Conclusions: This work shows that the sweat and sebum volatilome can be exploited for clinical applications. The workflow integrates non-invasive sampling, comprehensive chromatographic profiling, and advanced statistical modelling, representing a methodological contribution to analytical chemistry. Beyond COVID-19, the strategy provides a potential framework for volatile organic compound (VOC)-based diagnostics across different diseases and supports future development of sensor technologies for translation into healthcare practice. Full article

Microplastics (MPs) are persistent environmental pollutants of growing concern, threatening aquatic ecosystems worldwide. This study examined the influence of different pollution sources on the abundance, types, and polymer composition of MPs in two South African river systems, the uMsunduzi and Swartskop Rivers. Surface water and sediment samples were collected from sites impacted by industrial, wastewater, agricultural, and urban activities. Both rivers showed high MP contamination, with the highest concentrations detected in industrial and agricultural zones. Fibers dominated the particle shapes, while polyethylene (PE) and polypropylene (PP) were the most common polymers, alongside site-specific contaminants such as polytetrafluoroethylene (PTFE). Sediments generally contained higher MP concentrations and smaller particles than surface waters. These findings highlight the role of land use in shaping MP pollution profiles and the need for targeted mitigation strategies to protect freshwater systems. Full article

LiDAR has been widely applied in autonomous driving and mobile robotics. Recently, many studies focus on real-time point cloud segmentation, aiming to achieve higher accuracy while maintaining real-time inference speed. Current real-time methods mostly rely on 2D projection, which inevitably leads to spatial information loss. To address the limitations of 2D projection methods, we propose a Geometry-Enhanced Network called GENet that exploits spatial priors. The network employs an Atrous Separable Range Attention (ASRA) module to explicitly utilize spatial priors from range images, enabling geometry-aware feature aggregation with large receptive field at linear complexity. A Geometry-Context Modulation (GCM) mechanism is then used to calibrate semantic features, incorporating geometric priors while preserving the discriminative ability of original features across different categories. Experiments show that our method achieves efficient information fusion while maintaining real-time performance. Compared to existing methods, GENet requires fewer parameters and less computation, achieving a favorable balance between accuracy and efficiency. Full article

Lantana camara L. (Verbenaceae) is a medicinal plant widely used in traditional medicine in Angola, especially for its anti-inflammatory effects. This study evaluated the chemical composition of L. camara essential oil from leaves (Lc-EO) collected in Uíge Province, Angola. GC–MS analysis enabled the identification of 96 volatile compounds, with sesquiterpenes and monoterpenes as the predominant constituents. Among them, β-caryophyllene (14.49%), sabinene (9.13%), bicyclogermacrene (8.18%), α-humulene (5.66%), nerolidol (5.29%), and 1,8-cineole (5.14%) were identified as major components. The antioxidant activity of Lc-EO was assessed using DPPH, ABTS, and superoxide anion (O₂^•−) assays. Lc-EO showed strong activity in the DPPH assay (IC₅₀ = 0.72 µg/mL), moderate activity in the ABTS assay (IC₅₀ = 87.5 µg/mL), but minimal effect on O₂^•− radicals (IC₅₀ = 1491 µg/mL). It also significantly inhibited lipid peroxidation (IC₅₀ = 236.2 µg/mL). The anti-inflammatory activity of Lc-EO was assessed through its ability to inhibit protein denaturation, exhibiting a moderate effect with 28% inhibition. In silico ADMET predictions suggested drug-like properties and low predicted systemic toxicity for major compounds. The Artemia salina lethality assay indicated moderate general toxicity (IC₅₀ = 154.1 µg/mL), whereas the MTT viability assay revealed higher cytotoxic potency of Lc-EO (IC₅₀ = 31.58 µg/mL), highlighting model-dependent differences in sensitivity. Overall, L. camara essential oil shows relevant bioactivity consistent with its traditional use, particularly antioxidant and anti-inflammatory effects, while its cytotoxicity highlights the need for safety evaluation. These findings indicate that the assayed oil is a promising source of bioactive compounds, but further studies are required to support its development as a safe pharmaceutical raw material. Full article

Staphylococcus aureus is a major foodborne pathogen that poses persistent challenges to food safety. Antimicrobial photodynamic treatment (PDT) has emerged as a promising non-thermal antimicrobial strategy capable of effectively inactivating S. aureus, though accumulating evidence suggests that the bacteria may initiate adaptive responses to the PDT or even develop tolerance. However, the metabolic mechanisms underlying bacterial responses to PDT exposure, particularly under sub-lethal conditions, remain poorly understood. Thus, in the current study, untargeted metabolomics based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS) were employed to characterize intracellular metabolic alterations in S. aureus following curcumin-mediated PDT (40 µM curcumin, 425 nm blue light at intensity of 0.198 J cm⁻²). The obtained results revealed a clear separation between the control and PDT-treated groups, indicating sub-lethal PDT induced pronounced metabolic perturbations while preserving partial cellular viability. A total of 97 significantly differential metabolites were identified, encompassing a range of key metabolites associated with amino acid biosynthesis, lipid metabolism, and nucleotide metabolism, indicating the PDT-induced metabolic alterations in pathways could be associated with stress adaptation, membrane integrity, and energy metabolism. Collectively, these findings demonstrate that PDT, even at sub-lethal doses, induces extensive metabolic dysregulation in S. aureus, which potentially represent critical bactericidal vulnerability points target by PDT, yet may paradoxically participate in adaptive metabolic responses that support bacterial survival under PDT exposure. Further investigations are therefore warranted to elucidate the relationships among PDT-induced metabolic perturbations, bacterial inactivation, and long-term phenotypic adaptation. Overall, this work may provide mechanistic insight into PDT-induced antimicrobial action and support further optimization of PDT as an effective non-thermal intervention for food safety and preservation. Full article

As core materials in pavement structures, asphalt mixtures are characterized by intensive energy consumption and significant carbon footprints throughout their construction cycle, making their construction a typical high-carbon process in road engineering. Warm-mix technology, leveraging its key advantages of reducing mixing temperatures and cutting energy consumption and emissions, has emerged as a green alternative to hot-mix mixtures. However, existing studies have lacked systematic environmental impact assessments of combinations of asphalt from different oil sources and warm-mix technologies. This study focuses on the additive type warm-mix technology (Evotherm M1) and uses three typical oil sources of 70# road petroleum asphalt. Using headspace gas chromatography–mass spectrometry (HS–GC–MS) and Life Cycle Assessment (LCA) methods, a systematic analysis was conducted across three dimensions: multi-component pollutant emissions, full life cycle stages, and multi-type warm-mix technologies. The analysis focused on the influence of warm-mix treatment on Volatile Organic Compound (VOC) emissions, as well as energy consumption and carbon emission characteristics throughout the full life cycle of the construction phase. Results indicate that warm-mix treatment significantly inhibits VOC emissions from all three oil source asphalts. The largest reduction was observed in Asp-A (74.66%), followed by Asp-C (69.27%), and the smallest in Asp-B (46.47%). The VOC compositions shifted from being dominated by oxygenates to a coexistence of multi-components such as alkanes and aromatic hydrocarbons. In the life cycle of the construction phase, compared with hot-mix mixtures, warm-mix technology reduced total energy consumption by 5.50%–5.56% and carbon emissions by 4.47%–4.52%. Raw material production and mixture mixing stages were identified as the core links for energy consumption and carbon emissions, accounting for over 80% of the totals. Differences among oil sources mainly stemmed from refinery power structure and the temperature–viscosity properties of asphalt. The research results provide theoretical support for material selection and process optimization of green construction of asphalt pavement using additive-based warm-mix technology. Full article

In the context of plastic recycling, legislation is evolving and varies across regions, but it remains largely nonspecific. In the European context, producers of post-industrial and post-consumer recycled plastics must guarantee the same wholesomeness as virgin materials. However, they cannot maintain such strict control over incoming materials, because, since the secondary raw materials derived from separate waste collection, they are subjected to high variability in composition and heterogeneity over time. In this frame, a rapid, and easy-to-apply GC-MS method was developed. It employs a liquid–liquid extraction with acetone, followed by quantitative analysis with gas chromatography coupled to mass spectrometry (GC-MS). A combination of total ion chromatograms (TICs) and extracted ion chromatograms (EICs) was used. Adequate sensitivity was demonstrated in the selected concentration ranges for most of the analytes, with limits of quantification (LOQs) lower than the legislative limit, when existing. The results showed that the method is sufficiently accurate with recoveries ever higher than 68.3% and relative standard deviations (RSDr) smaller than 4.2%. This method allows, for the first time, the simultaneous quantification of 40 molecules at levels of a few ng/g. It ensures the possibility of obtaining real-time data for the production control system about the safety of the input materials, allowing immediate corrective action in the event of anomalies. This method is focused on PE and PP recycled plastics and is to be considered a screening method that allows for highlighting batches of incoming materials that are too contaminated to control the output material. This method was successfully tested analyzing some batches of plastics both in input and post-recycling. Full article

Endophytic fungi can influence plant development through diverse molecular mechanisms; however, their volatile organic compound VOC-mediated effects on agriculturally relevant crops remain insufficiently characterized. In this study, we examined the effects of VOCs produced by six grass-root-associated endophytic fungi—Cadophora fastigiata, Cordyceps fumosorosea, Chaetomium funicola, Epicoccum nigrum, Microdochium bolleyi, and Plectosphaerella cucumerina—on early growth of spring barley (Hordeum vulgare) and red clover (Trifolium pratense). In plate-in-plate VOC exposure assays, we assessed root system traits, root hair formation, and biomass accumulation. Responses to fungal VOCs were fungal species-specific but similar across barley and red clover. VOCs emitted by C. fastigiata and P. cucumerina were consistently associated with increased root growth, root hair proliferation, and seedling biomass, whereas VOCs from M. bolleyi and C. funicola resulted in neutral or growth-suppressing effects. A complementary seed inoculation experiment was conducted with barley, which showed fungal species–dependent contrasting effects consistent with the observations of VOCs treatment. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that C. fastigiata, the isolate associated with the strongest growth-promoting responses, emitted a diverse VOC profile dominated by sesquiterpenes, with 22 compounds identified. Together, these results demonstrate that VOCs emitted by grass-root-associated endophytic fungi exert reproducible, species-specific effects on early plant development occurring in phylogenetically distant species. The findings highlight the value of VOC-based assays for comparative functional screening of fungal isolates, providing a foundation for future studies that aim to link individual VOCs to plant growth responses. Full article

Common goldenrod (S. virgaurea L., Asteraceae) is recognised in traditional medicine as a folk remedy for kidney, urinary tract, and liver diseases, among others; however, its pharmaceutical potential remains largely unexplored. The pharmaceutical potential of the invasive species Canadian goldenrod (S. canadensis L.) in Europe is also of practical interest. The aim of the study was to compare the yield and composition of essential oils (EO) of flowering tops (20 cm long) of S. canadensis and S. virgaurea. The yield of EOs, hydrodistilled from S. canadensis (8 samples) and S. virgaurea (5 samples) herbs using the European Pharmacopoeia method, ranged from 2.7 to 14.9 mL/kg. The average EO yield in both goldenrod species was similar, but the composition differed. A total of 81 constituents were identified and semiquantified by GC-MS in the EOs of both Solidago species, eight of which have been found in these species for the first time. α-Pinene, limonene, and (E)-β-ocimene were the principal compounds in S. canadensis herb EO, and α-pinene, β-pinene, β-myrcene, and α-humulene were the principal compounds in S. virgaurea EO. It contained, on average, 39 times more benzyl salicylate than the EO from S. canadensis. Also, the amounts of viridiflorol (more in S. virgaurea) or β-bourbonene and (E)-β-ocimene (more in S. canadensis) can be used as a chemical fingerprint of both goldenrod species studied. The EO compositions were largely similar, with species-related differences supported by the presence of α-muurolene in S. virgaurea and its absence in S. canadensis. The pharmaceutical potential of V. canadensis as an invasive species is not yet sufficiently clear and requires further pharmacological studies. The composition of the EO seems to support the traditional use of goldenrod in the urological field. Full article