Search Results (12,899)

Transport emissions are a major source of urban polycyclic aromatic hydrocarbons (PAHs), posing risks to human health. While plant leaves and their epiphytic microbes contribute to PAH degradation, how plant traits and environmental factors affect this process remains unclear. This study examined 20 tree species in Beijing’s traffic corridors to explore PAH enrichment on leaves and the structure of phyllospheric bacterial communities. Results show that leaf area, morphology, and sampling height significantly influenced bacterial community assembly. Normalized Stochasticity Ratio (NST) analysis indicated that deterministic processes dominate on medium-sized leaves (11.8–40.1 cm²), simple leaves, and those below 2.3 m or above 3 m in height, whereas stochastic factors prevail on nano leaves, compound leaves, and leaves at low-position (<2.3 m). Although low-molecular-weight PAHs (2–4 rings) were predominant in leaves, Mantel tests revealed significant positive correlations between bacterial communities and high molecular weight PAHs (4–6 rings), such as benz(a)anthracene, benzo[e]pyrene, and picene. Spearman analysis identified 10 dominant bacterial taxa with PAH degradation potential, including Kocuria rosea, Serratia symbiotica, Massilia sp. WG5, and seven unclassified species from Hymenobacter, Sphingomonas, Roseomonas, Curtobacterium, and Deinococcus. Functional Annotation of Prokaryotic Taxa(FAPROTAX) prediction further associated 14 species across six genera, including Acinetobacter, Nocardioides, Gordonia, Rhodococcus, Clostridium_sensu_stricto_18, and Geobacter, with PAH degradation function. This work clarifies the composition and function of phyllospheric PAH-degrading bacteria in an urban traffic environment, offering a theoretical basis for enhancing degradation via bacterial consortia, biosurfactants, and optimized plant selection. Full article

To obtain data on the effects of ozonolysis on the structural and dynamic parameters of ultrafine fibers based on the binary compositions of poly-(3-hydroxybutyrate) (PHB) and polyvinylpyrrolidone (PVP) with varying ratios of polymer components ranging from 0/100 to 100/0 mass%, produced by electrospinning, a study was conducted. The morphology and structural–dynamic characteristics of the ultrafine fibers were examined. Comprehensive research was carried out, combining thermophysical measurements (DSC), dynamic measurements using an electron paramagnetic resonance (EPR) technique, scanning electron microscopy, and infrared spectroscopy. The influence of the mixture’s composition and ozonolysis on the degree of crystallinity of PHB and the molecular mobility of the TEMPO radical (tetramethylpiperidine-1-oxyl) in the amorphous regions of the PHB/PVP fiber material was demonstrated. The low-temperature maximum on the DSC thermograms provided information about the fraction of hydrogen bonds in the mixed compositions, allowing for the enthalpy of thermal destruction of these bonds in both the original and oxidized samples to be determined. The study showed significant changes in the degree of crystallinity of PHB, the enthalpy of hydrogen bond destruction, molecular mobility, moisture absorption of the compositions, and the activation energy of rotational diffusion in the amorphous regions of the PHB/PVP mixed compositions. It was established that within the 50/50% PHB/PVP ratio, an inversion transition occurs from the dispersion material to the dispersion medium. Ozonolysis induces a sharp change in the material’s structure. The conducted research provided the first opportunity to assess the impact of ozonolysis on the structural and dynamic characteristics of PHB/PVP ultrafine fibers at a molecular level. These materials may serve as a therapeutic system for controlled drug delivery. Full article

Additive manufacturing (AM) is a significant contributor to Industry 4.0. However, one considerable challenge is usually encountered by AM due to the bed size limitations of 3D printers, which prevent them from being adopted. An appropriate post-joining technique should be employed to address this issue properly. This study investigates the influence of key friction stir butt welding (FSBW) factors (FSBWFs), such as tool rotational speed (TRS), tool traverse speed (TTS), and pin profile (PP), on the weldability of 3D-printed PLA–Chromium (PC) composites (3PPCC). A filament containing 10% by weight of chromium reinforced in PLA was used to prepare samples. The material extrusion additive manufacturing process (MEX) was employed to prepare the 3D-printed PCC. A Taguchi-based design of experiments (DOE) (L9 orthogonal array) was employed to systematically assess weld hardness (WH), weld temperature (WT), weld strength (WS), and weld efficiency. As far as the 3D-printed samples were concerned, two distinct infill patterns (linear and tri-hexagonal) were also examined to evaluate their effect on joint performance; however, all other 3D printing factors were kept constant. Experimentally validated findings revealed that weld efficiency varied significantly with PP and infill pattern, with the square PP and tri-hexagonal infill pattern yielding the highest weld efficiency, i.e., 108%, with the corresponding highest WS of 30 MPa. The conical PP resulted in reduced WS. Hardness analysis demonstrated that tri-hexagonal infill patterns exhibited superior hardness retention, i.e., 46.1%, as compared to that of linear infill patterns, i.e., 34%. The highest WTs observed with conical PP were 132 °C and 118 °C for both linear and tri-hexagonal infill patterns, which were far below the melting point of PLA. The lowest WT was evaluated to be 65 °C with a tri-hexagonal infill, which is approximately equal to the glass transition temperature of PLA. Microscopic analysis using a coordinate measuring machine (CMM) indicated that optimal weld zones featured minimal void formation, directly contributing to improved weld performance. In addition, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also performed on four deliberately selected samples to examine the microstructural features and elemental distribution in the weld zones, providing deeper insight into the correlation between morphology, chemical composition, and weld performance. Full article

To address the limitations in the corrosion resistance of 316L stainless steel, ceramic reinforcements are increasingly utilized in additive manufacturing. However, their influence on corrosion behavior varies significantly. Via laser powder bed fusion (LPBF), 316L stainless steel composites reinforced with, respectively, 1 wt.% ceramic particles (TiC, SiC, SiO₂, WC, Y₂O₃) were fabricated, and the comparing microstructure and corrosion performance was investigated in this work. The results indicated that ceramic particle addition increased porosity (0.24% to 1.40%) due to the thermal expansion coefficient mismatch between particles and matrix and defects from incompletely melted particles. Microstructural analysis revealed that LPBF-processed 316L exhibited cellular sub-grain boundaries with distinct melt pool boundaries. Ceramic particle addition refined sub-grain boundaries to varying degrees across composites, accompanied by increased sub-grain boundary density. Interfacial reactions and thermal stresses induced crack formation in SiC/316L and SiO₂/316L composites. Electrochemical testing demonstrated that Y₂O₃/316L exhibited the highest corrosion resistance, followed by TiC/316L and WC/316L. The corrosion resistance of the as-built L-BPF 316L matrix was inferior to that of these three composites. Conversely, SiC/316L and SiO₂/316L exhibited the poorest corrosion resistance. The optimized corrosion resistance of Y₂O₃/316L is hypothesized to result from pronounced grain refinement and the highest sub-grain boundary density, which provided abundant nucleation sites for passive film formation. Conversely, SiC/316L and SiO₂/316L showed lower corrosion resistance than the as-built L-BPF 316L matrix due to elevated defect density. Corrosion morphology analysis indicated preferential corrosion propagation along melt pool boundaries in 316L, TiC/316L, WC/316L, and Y₂O₃/316L. In contrast, pores and microcracks in SiC/316L and SiO₂/316L accelerated pit nucleation, indicating failure dominated by localized corrosion mechanisms. Full article

The fallopian tubes are critical segments of the female reproductive tract and are essential for transporting gametes and embryos. It creates a conducive environment necessary for successful fertilization, early embryo development, and embryo transport. The cellular composition and function of the fallopian tube are tightly regulated by the sex hormones estradiol and progesterone. Therefore, any pathological/ metabolic condition or exposure to exogenous agents with the potential to alter endocrine levels can have a significant impact on fallopian tube function and health. This review summarizes the effects of medications, infections, pathological conditions, lifestyle choices, and environmental factors that can significantly impact the morphology, histology, cellularity, and functionality of the fallopian tube. Full article

Direct metal laser sintering (DMLS) is an advanced powder bed fusion (PBF) technology widely utilized in the medical device and aerospace sectors for the production of intricate and high-value components. The powdered metal materials used in the DMLS process can be expensive, and it is uncommon for a single build to exhaust an entire batch of powder. As a result, the un-melted powder characterized by differences in particle size and morphology compared to fresh virgin powder is recommended to be recycled for use in subsequent builds. This comprehensive review delves into the essential role that powder quality plays in the realm of DMLS with a particular focus on effective and sustainable powder recycling strategies. In this study, the effects of recycling stainless steel powder, specifically used in the DMLS process, are rigorously investigated in relation to the quality of the finished components. This paper monitors critical powder material characteristics, including particle size, particle morphology, and the overall bulk chemical composition throughout the recycling workflow. Furthermore, this review brings to light significant challenges associated with the recycling of stainless steel powders, such as the need to maintain consistency in particle size and shape, manage contamination risks, and mitigate the degradation effects that can arise from repeated usage, including wear, fragmentation, and oxidation of the particles. In addition, this paper explores a variety of recycling techniques aimed at rejuvenating powder quality. These techniques, including sieving, blending, and plasma spheroidization, are emphasized for their vital role in restoring the integrity of recycled powders and facilitating their reuse in innovative and efficient manufacturing processes. Full article

Background: Neuroblastoma (NB) is the most common extracranial paediatric solid cancer, with a 50% survival rate for high-risk patients. Circulating tumour cells (CTCs) are malignant cells shed by the primary tumour and metastatic sites that circulate in the bloodstream. CTCs form clusters with themselves (homotypic) or other cell types (heterotypic). Objectives: To use previously generated ImageStreamX Imaging Flow Cytometer data from blood samples from 24 patients across all NB risk groups, to examine for the presence of CTC clusters. Methods: Immunofluorescence and brightfield morphology were used to identify clusters followed by analysis using IDEAS image analysis software. Results: The mean number of clusters detected per sample was 87 (range, 0–725). Of the clusters detected, 1967/2094 (93.9%) were heterotypic and only 127/2094 (6.1%) were homotypic and found in 6/24 patients. Interestingly, in 3/24 patients, at least one cluster (median, 2 and range, 1–18) was found, but no single CTCs were detected. Clusters mostly comprised two cells (62.8%), with the maximum number of cells in homotypic and heterotypic clusters being four and eight, respectively. Conclusions: These results highlight that imaging flow cytometry can be used to detect and characterise CTC clusters in peripheral blood samples from NB patients, leading to further research exploring the composition and role of CTC clusters in NB metastasis. Full article

The growing demand for sustainable alternatives to synthetic composites has increased the interest in natural-fibre-reinforced composites (NFRCs), due to their reduced environmental impact. This study presents a comparative investigation of the mechanical properties of mono-fibre and intraply sisal/flax hybrid composites as cost-effective bio-based solutions. Flax offers high tensile performance but is constrained by higher cost and geographical availability. Sisal, on the other hand, is widely available at lower cost, but exhibits a coarser morphology and reduced processing versatility. Mechanical testing demonstrated that intraply hybrids achieved well-balanced performance, with reduced flax content still delivering competitive tensile strength and stiffness when compared to the higher performing mono-fibre flax composites. However, sisal-rich and hybrid laminates outperformed mono-fibre flax composites in transverse and shear behaviour, with the 67% sisal/33% flax hybrid composite exhibiting the highest transverse properties and the 33% sisal/67% flax hybrid achieving the highest shear properties. Rule-of-mixtures models predicted longitudinal tensile behaviour effectively, while Halpin–Tsai models successfully estimated shear but not transverse and compressive properties. Compressive strength showed limited variation across configurations. Failure analysis identified intra-yarn fracture in flax, limited resin infiltration in sisal, and compressive failure modes such as brooming and microbuckling. Overall, intraply sisal/flax hybrid mats provide a structurally efficient, sustainable, and economically viable alternative to mono-fibre natural composites. Full article

Very-high-cycle fretting fatigue (VHCFF) behavior at elevated temperatures is critical for the safety and longevity of aerospace components. This study investigates the VHCFF mechanisms of laser-clad IN718/20%WC composite coatings at 650 °C. Fatigue tests were conducted to generate S-N data, and the resulting wear and fracture morphologies were characterized. Crack initiation was found to preferentially occur in grains exhibiting higher Schmid factors, lower elastic moduli, and larger equivalent sizes. To simulate fretting fatigue, a crystal plasticity finite element model (CPFEM) incorporating the actual microstructure was developed. An improved fatigue indicator parameter (FIP) was proposed, which integrates multiple physically significant factors including plastic strain, dislocation density, elastic modulus, and grain size. Life predictions based on a critical FIP value demonstrated high accuracy, with 97.6% of the results falling within a ±3.5 scatter band of the experimental data, confirming the model’s effectiveness in predicting crack initiation life. Full article

A protocol was developed for the isolation and characterization of extracellular vesicles (EVs) from Coffea arabica cell suspension cultures (CSCs). The isolation method involved differential ultracentrifugation of the CSC filtrate, yielding two fractions: the pellet after 100,000×g for 36 min (100k×g) and the pellet obtained from the previous supernatant after 125,000 g for 6 h (125k×g). Both fractions were characterized by size, morphology, and proteomic profiles (ProteomeXchange identifier PXD071909). While no significant differences in average EV size were observed between the two fractions, proteomic analysis revealed distinct quantitative and compositional variations. The 100k×g fraction was enriched in proteins associated with cell periphery, plasma membrane, and extracellular region, whereas the 125k×g fraction predominantly contained proteins from the extracellular region. Proteomic marker analysis confirmed that both fractions contained protein EV markers, such as transmembrane and transport proteins, soluble EV-associated proteins, and proteins targeted to the extracellular environment or cell wall. Conversely, negligible contamination from non-EV-related proteins was detected. Furthermore, transmission electron microscopy (TEM) showed that the average size of the fractions was consistent with that reported for plant EVs. These findings demonstrate that the protocol utilized to isolate EVs from coffee CSC applies to the release of such vesicles without mechanical harsh grinding that leads to tissue/cell rupture and consequent contamination by other cell components. EVs obtained from coffee CSC represent a valuable and scalable platform, paving the way for the development of tools for biotechnological applications. Full article

The influence of potassium oxide (K₂O) doping on the hydrodeoxygenation (HDO) performance of trimetallic CoMo–Ni/Al₂O₃ catalysts was systematically investigated using guaiacol as a lignin-derived model compound. Catalysts containing 0, 1, 3, and 5 wt% K₂O were synthesized and characterized by SEM-EDS, N₂ physisorption, XRD, FTIR, and HRTEM. SEM micrographs showed homogeneous morphologies with no significant agglomeration, while EDS analysis confirmed elemental compositions close to nominal values, with K₂O contents increasing proportionally and maintaining uniform surface distribution. Adsorption–desorption isotherms confirmed mesoporous structures with specific surface areas ranging from 258 to 184 m² g⁻¹, decreasing with increasing K₂O loading. XRD revealed γ-Al₂O₃, NiO, (NH₄)₃[CoMo₆O₂₄H₆]·7H₂O, and K₂O phases, with slight peak shifts indicating surface modification rather than lattice incorporation of K⁺. FTIR spectra evidenced characteristic polyoxomolybdate vibrations and metal–oxygen interactions with alumina. HRTEM revealed MoS₂ slab lengths between 1.85 and 2.51 nm, stacking numbers from 2.08 to 3.17, and Mo edge-to-corner ratios (f_e/fc) between 1.39 and 2.43, corresponding to dispersions of 0.45–0.57. Guaiacol conversion remained high (≥95%) for all catalysts, while HDO selectivity strongly depended on K₂O content. At 5 wt% K₂O, cyclohexane selectivity reached 81.3% with an HDO degree of 65%, compared to 52.0% and 31% for the undoped catalyst. Pseudo-first-order kinetic analysis revealed that potassium promotes demethylation and demethoxylation steps while suppressing rearrangement pathways, steering the reaction network toward direct deoxygenation. These results demonstrate that K₂O acts as an efficient structural and electronic promoter, enabling precise control of HDO selectivity without compromising catalytic activity. Full article

Advances in modern industry largely depend on the development of high-performance materials. In this study, the influence of hexagonal boron nitride (h-BN) filler on the performance of glass fiber/epoxy laminates was systematically investigated. Composites containing h-BN with different particle sizes (65–75 nm and 790 nm) and contents (0.2 and 0.4 wt.%) were fabricated, and their mechanical (tensile, in-plane shear, hardness, impact), thermal (Differential Scanning Calorimetry, DSC), electrical (volume resistivity), and spectroscopic (Fourier Transform Infrared Spectroscopy, FTIR) properties were examined. The results demonstrated that specimens with 65–75 nm h-BN at 0.2 wt.% exhibited the highest tensile and shear strengths, whereas those with 790 nm h-BN at 0.4 wt.% showed superior impact resistance and hardness. DSC analyses revealed that h-BN addition increased the glass transition temperature (Tg), while FTIR confirmed interfacial interactions between h-BN and the epoxy matrix. Electrical measurements indicated that h-BN preserved the insulating nature of the composites, with only limited reductions in resistivity observed at higher contents of larger particles due to morphological effects. Overall, these findings highlight that h-BN filler enhances load transfer efficiency, thermal stability, and mechanical reliability, offering significant potential for applications requiring multifunctional performance, such as aerospace, marine, and electrical and electronic insulation systems. Full article

Global change represents one of the most pressing threats to ecosystems, profoundly influencing habitats and redefining management and conservation priorities. Rising temperatures, altered precipitation regimes, invasive species and the increasing frequency of extreme events, such as prolonged droughts and wildfires, are modifying the composition, structure, and resilience of forests. Often, these changes result in habitat fragmentation, which isolates populations and diminishes their ability to adapt. This situation calls for an urgent reassessment of traditional protected area management practices. In response to climate change, it is essential to prioritize conservation strategies that focus on adaptation and maintaining biodiversity, while combating the spread of invasive species. For this reason, this study aims to analyze the impact of global changes on forest vegetation within protected areas, using Aspromonte National Park, a highly biodiverse region, as a case study. It evaluates the transformations in habitat cover and fragmentation over twenty years by comparing the 2001 vegetation map of Aspromonte National Park with the Map of Nature of the Calabria region, to quantify spatial and temporal habitat variations using QGIS 3.42.3 software. Morphological Spatial Pattern Analysis (MSPA) and FRAGSTATS v4.2 were employed to evaluate habitat fragmentation. The results indicate that most forest habitats have experienced a slight increase in area over the past 20 years. However, the area occupied by Pinus nigra subsp. laricio forests (Habitat 42.65) has decreased significantly, most likely due to repeated fires in previous years. In conclusion, this study establishes a scientific foundation for guiding conservation policies in the protected area and promoting the resilience of native plant communities against global change. This is essential for ensuring their survival for future generations while mitigating both habitat fragmentation and the introduction and spread of non-native species. Full article

In deep-sea environments characterized by global climate change and frequent typhoons, the long-term structural stability of offshore buildings depends on the adaptability of their morphology to complex, multi-directional wind loads. Current offshore engineering predominantly emphasizes passive structural resistance, with a notable lack of research on proactive wind-diversion strategies from a morphological design perspective. Utilizing the PHOENICS-FLAIR platform and the Chen–Kim k-ε turbulence model, this study conducted numerical simulations across eight typical wind direction scenarios. The independence of the medium-mesh scheme was verified through Grid Convergence Index (GCI) analysis, and the high reliability of the numerical model was validated against the AIJ Case A wind tunnel experiments. Quantitative results demonstrate that, compared to the benchmark rectangular prism, the optimized composite polyhedral form featuring “curved sloped facades” performs superiorly under multi-directional conditions: the maximum positive wind pressure is reduced by up to 50%, and the total surface wind pressure differential decreases by 62–65%. This research proves that a polyhedral continuous envelope configuration can achieve balanced aerodynamic performance across all wind directions, providing a feasible direction for the design strategy of offshore buildings to shift from “passive resistance” to “proactive diversion”. Full article

This study evaluated changes in nutritional components and antinutritional factors in rapeseed meal before and after microbial fermentation. It further investigated the enhancements in its nutritional value and the growth-promoting effects of fermented rapeseed meal on broiler chickens. A total of 180 one-day-old male Arbor Acres (AA) broilers were randomly allocated into 3 treatment groups, with 6 replicates per group and 10 birds per replicate. The broilers were fed a basal diet (CON), a diet with 5% soybean meal (SBM) replaced by RSM (RSM-5), or a diet with 5% SBM replaced by FRSM (FRSM-5). The date of the experiment was 28 June 2025. The results showed that FRSM improves protein quality and reduces the levels of antinutritional factors, including glucosinolates (GSL), phytic acid (PA), and condensed tannins (CT), compared with unfermented RSM. Additionally, FRSM enhances antioxidant capacity in vitro, significantly enhancing the scavenging rates of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, hydroxyl radicals (•OH), and superoxide anion radicals (O₂•⁻). In the broiler feeding trial, the FRSM-5 group had significantly higher average daily gain (ADG) during the periods of 22–42 d and 1–42 d (p < 0.05), along with a significantly lower feed to gain ratio (F/G) (p < 0.05), compared with the CON and RSM-5 groups. Compared to the CON group, the FRSM-5 group showed a significantly higher slaughter rate (SR), full eviscerated rate (FER), and breast muscle rate (BMR) (p < 0.05), whereas the RSM-5 group had significantly lower SR and FER (p < 0.05). The activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) in the serum and liver of the FRSM-5 group were significantly higher than those in the CON and RSM-5 groups (p < 0.05), and the serum immunoglobulin (IgA, IgG, and IgM) levels were significantly elevated (p < 0.05). Furthermore, compared with the CON and RSM-5 groups, the FRSM-5 group exhibited a significant increase in duodenal villus height (VH) (p < 0.05), a significant reduction in duodenal crypt depth (CD) (p < 0.05), and a consequent significant increase in the VH/CD (p < 0.05). In conclusion, microbial fermentation effectively enhances the nutritional value of RSM by improving its nutrient composition and reducing antinutritional factors. Replacing 5% SBM with FRSM in broiler diets significantly improves growth performance, enhances antioxidant capacity and immune function, and optimizes intestinal morphological structure, thereby replacing part of the soybean meal in broiler diets. Full article