Search Results (3,530)

Biochar, a carbon-rich material traditionally used to improve soil health and as a feed additive, has recently attracted attention for its potential biological activity. This study examined the effects of an aqueous biochar extract (BC-AE) on human intestinal epithelial cells (Caco-2), focusing on its influence on cell viability and apoptosis. The metabolic activity of Caco-2 cells exposed to BC-AE was first evaluated using an MTS assay. A concentration of 3 mg/mL, which promoted Caco-2 metabolic activity, was selected for further testing at 24 and 72 h. The effect of BC-AE on cell viability was assessed by epifluorescence microscopy (morphology) and flow cytometry (apoptosis profiling). The transcriptional response of cell viability-related genes (BAX, BAD, BCL-2, BCL-xL, MCL-1, P21, and P53) and microRNAs (miR-15b, miR-19, miR-21, miR-33a, miR-155, and miR-486) was analyzed by RT-qPCR. In parallel, selected proteins (BAD, BAX, BCL-2, and MCL-1) were examined by Western blotting. We showed that BC-AE decreased cell viability after 24 h via late apoptosis, while 72 h exposure increased necrosis without further viability loss. Both BAX and MCL-1 protein levels increased in Caco-2 cells after 72 h of BC-AE treatment, and miR-15b and miR-21 were upregulated, suggesting the involvement of a regulatory mechanism controlling cell survival. The obtained findings highlight the importance of considering both concentration and exposure duration when assessing biochar bioactivity and represent an additional contribution to the ongoing effort to better understand the biological role. Full article

The genus Xylaria comprises numerous species, particularly prevalent in tropical ecosystems such as those of Ecuador. Despite its ecological importance, the taxonomy of the genus remains challenging, and much of its diversity in the Neotropics remains under-documented. This study provides a preliminary characterization of the Xylaria diversity at the Estación Científica San Francisco, an Andean biodiversity hotspot in Southern Ecuador. Through an integrated approach including detailed macro- and micro-morphological descriptions and nuclear ribosomal DNA (nrDNA ITS and LSU) phylogenetic analyses, 20 Xylaria specimens were examined. As a result, ten species were recognized: Xylaria adscendens, X. cf. anisopleura, X. apiculata, X. curta, X. enterogena, X. fissilis, X. globosa, X. aff. telfairii, X. tuberoides, and X. aenea, the latter representing a new record for Ecuador. The phylogenetic analysis presented here serves as a preliminary systematic positioning of these specimens within the genus rather than a comprehensive global reconstruction. While these ribosomal markers provided preliminary insights into species relationships, partial incongruence with morphospecies highlights the evolutionary complexity of certain lineages and underscores the need for future multilocus studies. Furthermore, four additional phylotypes found in their anamorphic state are documented, suggesting that local diversity exceeds current records. By providing detailed morphological documentation supported by preliminary barcode data from a poorly sampled region, this study contributes vital information to the global understanding of Xylaria and underscores the importance of Southern Ecuador as a reservoir of fungal diversity. Full article

Foaming technology can effectively reduce the viscosity of polymer-modified asphalt and significantly decrease energy consumption during pavement construction, making it an effective approach for achieving low-carbon pavement construction and maintenance. However, mechanically foamed asphalt relies on specialized equipment and requires strict parameter control. Although water-based foaming methods using zeolites or ethanol can alleviate these issues to some extent, they still present disadvantages such as significant variability in foaming performance and potential risks during transportation and construction. Therefore, this study investigates the feasibility of using crystalline hydrates with high water of crystallization for micro-foamed asphalt. Three types of micro-foamed SBS-modified asphalt (MFPA) were prepared using hydrates with different contents of water of crystallization. Physical property tests, foaming characteristic parameters, viscosity–temperature analysis, Fourier transform infrared spectroscopy (FTIR), adhesion tensile tests, scanning electron microscopy (SEM), and fluorescence microscopy were conducted to evaluate their effects on the physical and chemical properties, viscosity reduction performance, adhesion, and compatibility of SBS-modified asphalt. Furthermore, dynamic shear rheometer (DSR) tests, bending beam rheometer (BBR) tests, fatigue life modeling, and morphological analysis were employed to investigate the rheological properties, fatigue life, and bubble evolution behavior of the MFPA system. The results indicate that utilizing the thermal decomposition characteristics of crystalline hydrates with high water of crystallization (Na₂SO₄·10H₂O, Na₂HPO₄·12H₂O, and Na₂CO₃·10H₂O) to release H₂O and CO₂ in SBS-modified asphalt for micro-foaming is a short-term reversible physical viscosity reduction process. The maximum expansion ratio (ERmax) of MFPA reaches 8–10, the half-life (HL) remains stable at approximately 180 s, and the foaming index (FI) peak is about 1160. The construction temperature can be reduced by 10–15%, and the viscosity reduction effect remains stable within 60 min. Compared with unfoamed SBS-modified asphalt, the compatibility, rutting resistance, and fatigue life of MFPA increase by approximately 65%, 32%, and 30%, respectively, while the low-temperature performance decreases by 18%. Under the same short-term and long-term aging conditions, MFPA exhibits better aging resistance. Specifically, its rutting resistance increases by 37%, and fatigue resistance improves by 30% compared with aged SBS-modified asphalt, while the low-temperature performance remains essentially unchanged. Full article

Carbon fiber-reinforced thermoplastic (CFRTP) composites are now widely used in many fields. Ultrasonic welding (UW) is a key technology for joining these materials. The control mode of UW has a great effect on the quality of the welded joints. However, there is still not enough research comparing the different welding control modes. This paper investigates the effects of the time control, energy control, and displacement control modes on the ultrasonic welding quality of carbon fiber-reinforced polycarbonate (CF/PC). A flat PC film is used as the energy director (ED). The evaluation focuses on the lap-shear strength (LSS), macro- and micro-morphology, fracture surface characteristics and power–displacement curves of the welding process. Furthermore, significant differences are observed in the temperature field evolution and joint failure modes across the different control modes and process parameters. Results indicate that the displacement control mode achieves the highest joint quality and process stability, yielding a maximum LSS of 30.6 MPa. A correlation analysis reveals that the displacement–energy relationship exhibits the strongest coupling, and the Pearson correlation coefficient r is 0.896. Full article

Background/Objectives: This study aimed to characterize macro- and micro-morphological properties of the supraspinatus tendon (SST) in para swimmers during the chronic stage of rotator cuff tendinopathy, integrating ultrasound assessments of tendon thickness, peak spatial frequency radius (PSFR) for collagen organization, acromiohumeral distance (AHD), and occupation ratio to evaluate subacromial impingement risk. Methods: In a cross-sectional design, 43 elite para swimmers (aged 18–30 years, S7–S10 classes with lower extremity impairments) from Para Swimming Team Poland were divided into rotator cuff tendinopathy (RC; n = 22) and asymptomatic control (CON; n = 21) groups. Measurements on the dominant shoulder utilized B-mode ultrasound (Alpinion X-CUBE 90) to assess SST thickness at 5, 10, and 15 mm proximal to the greater tuberosity, PSFR via MATLAB-analyzed spatial frequency spectra, AHD, and occupation ratio. Two-way and one-way ANOVAs assessed group and measurement effects (p < 0.05); Pearson correlations examined the relationships between thickness and PSFR. Results: Para swimmers with tendinopathy exhibited greater SST thickness across sites (p < 0.001, η² = 0.63), higher PSFR at all intervals (p ≤ 0.009, η² = 0.53) peaking at 10 mm, wider AHD (p = 0.002, η² = 0.21), and lower occupation ratio (p < 0.001, η² = 0.44) versus controls. Strong positive correlations linked thickness and PSFR proximally (r = 0.75–0.79, p < 0.001). Conclusions: Chronic tendinopathy in para swimmers manifests as thickened SST with collagen disarray, altered subacromial space, and impingement risk, distinguishing pathological from healthy tendons. Integrated ultrasound metrics aid diagnosis and inform interventions for overhead athletes with locomotor disorders. Full article

Combined pulse laser systems combining continuous-wave (CW) lasers and nanosecond pulsed lasers have shown clear advantages in metal ablation and surface modification. However, the plasma shielding effect induced by nanosecond pulses and the associated shock-wave phenomena in hybrid laser systems remain insufficiently investigated, particularly regarding their influence on CW laser energy coupling. In this study, the ablation behavior of metal targets under the combined irradiation of a 500 W CW laser and nanosecond pulsed lasers with pulse energies ranging from 0.4 J to 1.0 J was investigated. High-speed plasma imaging was employed to analyze laser–material interaction characteristics, including absorption behavior and molten material ejection, while high-speed infrared thermography was used to monitor transient temperature evolution during combined pulse laser processing. Macroscopic and microscopic analyses were conducted to characterize damage morphology, and a three-dimensional surface profilometer was used to quantitatively evaluate ablation efficiency. The results show that, under combined pulse laser irradiation, the removed volume increased from 0.05 mm³ to 0.618 mm³ and the ablation depth increased from 0.136 mm to 0.776 mm. Compared with CW laser processing alone, the ablation efficiency was markedly enhanced. This improvement is attributed to the combined effects of optimized energy deposition, thermal distribution, and material response. In addition, the plasma shielding effect was observed to vary with nanosecond pulse energy, indicating that precise energy control is critical for performance enhancement. This study demonstrates the potential of combined pulse laser technology for high-efficiency and high-precision metal surface processing and micro–nano fabrication. Full article

In this study, Nd-Fe-B magnets with different degrees of alignment were prepared by adjusting the strength of the alignment magnetic field. The mechanism of influence of alignment degree on the densification of magnets was systematically investigated. The shrinkage rates of the magnets after sintering were calculated, and the results showed that the unoriented magnets exhibited similar shrinkage in different directions, displaying isotropic shrinkage behavior. With the increase in the degree of alignment, the magnets showed significant differences in shrinkage across different directions, presenting anisotropic shrinkage characteristics. In addition, the microstructural analysis revealed that the alignment degree also exerted a certain influence on the micromorphology of the magnets. The grain size parallel to the c-axis was larger than that parallel to the a-axis, which indicates that the alignment degree plays a crucial role in the anisotropic densification of the Nd-Fe-B magnets. Full article

Mexican species of Lactifluus have often been identified using names of morphologically similar Old World taxa. However, integrative approaches combining morphological and molecular data have revealed a high level of previously unrecognized diversity in the region. Here, two new species from lowland tropical Quercus forest are described: one in section Piperati (subgenus Lactifluus), characterized by pale yellow basidiomes and another in section Albati (subgenus Lactariopsis), with whitish basidiomes. The two taxa are distinguished by a unique set of macro- and micromorphological features, and their recognition is strongly supported by phylogenetic evidence from a concatenated dataset including nc ITS rDNA, nc 28S rDNA and the 6–7 region of the second largest subunit of the RNA polymerase II (rpb2). Full article

Based on temperature–stress coupling simulation, a thermal source model for nanosecond pulsed hollow cathode electron beam surface modification is proposed. Dynamic thermal-stress changes from beam–surface interaction and their influence on micro–nano characteristics were systematically investigated. By analyzing maximum temperature/stress dynamics, cross-sectional remelted layer variations, and heating/cooling rates, the temperature and stress distribution in the micron-scale surface layer was comprehensively revealed, validating the model’s rationality. Combined with low, medium, and high pulse count experiments, the effects of thermal and stress factors on surface morphology and grain refinement were studied, elucidating underlying mechanisms through numerical correspondence. Results show irradiation effects confined to a 1.5–2 mm localized region, with extreme temperature changes (~10³ K) and stress variations (10³–10⁴ MPa) within tens of nanoseconds. Heating rates reached 10¹¹ K/s, cooling rates 10⁹–10¹⁰ K/s, exceeding microsecond pulsed beams by one to two orders. Simulated remelting zone diameter and thickness agreed well with experiments, confirming model validity. Grain refinement is primarily driven by rapid temperature distribution, generating instant solidification nucleation sites, with a secondary contribution from high-stress-induced plastic deformation forming sub-grains. Full article

Global warming has significantly intensified the risks of summer heatwaves, making outdoor thermal comfort during extreme heat periods a critical research focus. Under centralized rural village reconstruction policies, traditional settlements are being replaced by regularized modern communities characterized by new materials and standardized layouts. However, the impact of these morphological transitions on the micro-scale thermal environment remains under-researched, with a notable lack of comparative perspectives between traditional organic and modern standardized typologies. This study identifies six representative zones based on spatial configuration. By integrating UAV photogrammetry (Pix4Dmapper v4.5), AutoCAD 2019, and QGIS (v3.22), morphological characteristics were quantified, followed by microclimate simulations using ENVI-met v5.9. The results reveal that while peak daytime Physiological Equivalent Temperature (PET) in the standardized zones (49.2–51.8 °C) is slightly lower than in traditional zones (53.5–55.2 °C), a phenomenon of thermal homogenization emerges in the former. Specifically, values in standardized zones are highly concentrated around the median (53.5 °C), contributing to a significant upward trend in the minimum PET values, with nearly all sampling points exceeding 47.0 °C. Quantitative analysis identifies green coverage and perviousness as primary cooling drivers, while spatial openness and imperviousness promote thermal homogenization. In contrast, traditional zones retain critical cool refuges due to their spatial heterogeneity. This research provides an empirical foundation and quantitative reference for understanding the thermal performance differences across different rural spatial typologies. The findings offer insights for planners to optimize street layouts and shading strategies, ultimately mitigating heat stress and fostering climate-resilient modern countryside development. Full article

Using the ultrasonic burnishing process to fabricate micro-textures is one of the effective methods to improve the hydrophobic properties of workpiece surfaces. In this study, three ultrasonic burnishing strategies—single-pass ultrasonic burnishing process (SUBP), two-pass ultrasonic burnishing process with reverse feed direction (TUBP-RF), and two-pass ultrasonic burnishing process with forward feed direction (TUBP-FF)—were employed to fabricate micro-textures on 316 stainless steel pipes. The effects of burnishing strategy and feed rate on surface morphology and hydrophobic performance were investigated. TUBP-RF introduces reverse feed in the second pass, generating tangential forces in the opposite direction that induce secondary plastic flow and material accumulation at texture intersections. The results show that surface hydrophobicity first increased and then decreased with increasing feed rate, reaching its maximum at 0.7 mm/r. TUBP-RF achieved the highest contact angle of 108°, representing increases of 18.4% and 12.1% compared with SUBP and TUBP-FF, respectively. Among the three strategies, TUBP-RF produces interlaced micro-textures with larger peak height Rp, medium peak spacing RSm, and reduced effective solid contact area, facilitating air entrapment beneath water droplets and promoting a Cassie–Baxter wetting state. Furthermore, under the optimal parameters of the TUBP-RF process, the machined surface improved droplet sliding speed, reduced the sliding time by 61.7% compared with the original surface. The TUBP-RF strategy effectively enhances surface hydrophobic properties by constructing interlaced micro-textures, offering new insights for optimizing the ultrasonic burnishing process. Full article

To investigate the influence of humus on the corrosion behavior of high-tin bronze in soil environments, potentiostatic polarization was applied to simulate early-stage corrosion under controlled conditions. Open-circuit potential and potentiodynamic polarization tests were performed, and corrosion products were characterized by stereo microscopy, SEM-EDS, and confocal Raman spectroscopy. A Cu–Sn–Pb ternary alloy was examined in simulated archaeological soil solutions with selective humus addition at different pH values. A bilayer structure, consisting of a secondary corrosion layer and a semi-corroded transition zone, developed in all media, with more extensive corrosion under weakly acidic conditions. In acidic environments, humus enhanced preferential α-phase corrosion, associated with copper depletion and tin enrichment as SnO₂. Under weakly alkaline conditions, humus mainly affected surface color and micro-morphology without altering the overall corrosion pattern. Electrochemical testing reproduced corrosion layer structures similar to those formed during early burials, but differences in morphology were observed. The results suggest that, as an accelerated corrosion technique, electrochemical methods can reproduce key features of early-stage corrosion in high-tin bronze and serve as an effective tool for monitoring corrosion behavior. Full article

Despite extensive pore-scale studies on oil–water displacement, quantitative understanding of the dynamic evolution of residual oil morphology and waterflooding efficiency in geologically heterogeneous sandstones remains limited, particularly under large water-injection multiples. To better understand pore-scale oil–water distribution and its influence on enhanced oil recovery, this study utilized Micro-CT combined with SEM-EDS to examine the 3D pore structure and oil–water phase evolution in a heterogeneous sandstone sample from the Xiayang Formation, Wushi Sag, Zhanjiang. Mineralogical analyses reveal that dolomite cementation and vermicular kaolinite infilling introduce strong pore-scale heterogeneity by selectively reducing pore connectivity and permeability, posing challenges for uniform fluid displacement. A 30% KI solution was used to enhance X-ray attenuation of the aqueous phase, enabling clear discrimination between oil and water. Micro-CT reconstructions reveal a relatively uniform pore network dominated by medium-to-large intergranular pores. As the water-injection multiple increases, water progressively invades larger pores, while residual oil is immobilized by capillary forces within micro-throats, forming isolated clusters. The oil-droplet size distribution broadens from a narrow range (50–100 µm) to a wider one (200–300 µm), indicating interfacial destabilization and droplet coalescence. Quantitative analysis indicates that oil saturation decreases from approximately 90% to 36%, while waterflooding efficiency increases rapidly to ~45% at 1 PV and gradually approaches a plateau of ~60% beyond 500–1000 PV. This waterflooding plateau is attributed to capillary trapping and pore-scale connectivity limitations imposed by mineral-induced heterogeneity, which prevent further mobilization of residual oil despite continued water injection. This study advances pore-scale waterflooding research by combining mineralogical heterogeneity with long-term micro-CT imaging, revealing the pore-scale mechanisms controlling residual oil evolution and ultimate waterflooding limits in realistic sandstone. Full article

Phosphorus deficiency is a key factor limiting plant growth in desertified grasslands. Elucidating the adaptive strategies of pioneer plants that integrate root morphology and microbial interactions is crucial for understanding the natural restoration of ecosystems. This study investigated the strategies employed by Kengyilia hirsuta, a pioneer grass species in desertified grasslands, to adapt to low-phosphorus environments. By conducting sand culture experiments under varying phosphorus levels (low, optimal, and high), we focused on elucidating the synergistic adaptive mechanisms involving the root–rhizosheath system. The results showed that the rhizosheath serves as a critical micro-ecological niche for enriching arbuscular mycorrhizal fungi (AMF) and enhancing phosphatase activity. Under low-phosphorus stress, the plant strengthened root hair development and its symbiotic association with AMF, which markedly increased acid phosphatase activity and led to the highest phosphorus use efficiency. At the optimal phosphorus level, the plant developed an efficient “rhizosheath–mycorrhiza” synergistic system, characterized by high AMF colonization and spore density, facilitating optimized carbon–phosphorus exchange. Under phosphorus-sufficient conditions, the adaptive strategy transitioned towards root morphological plasticity, exemplified by increased surface area and branching. Multivariate analysis revealed that the phosphorus absorption efficiency of K. hirsuta is co-regulated by both morphological adaptation and symbiotic optimization. This study elucidates the mechanisms of nutrient stress adaptation in desertified grassland plants, providing a theoretical foundation for understanding the natural restoration processes of degraded ecosystems. Full article

Tyre and road wear particles (TRWPs) represent one of the most significant yet under-recognised sources of global microplastic pollution, contributing up to 28% of total emissions. Generated from the complex interaction between vehicle tyres and road surfaces, TRWPs are chemically diverse, morphologically heterogeneous, and environmentally persistent, making their detection and management particularly challenging. This review provides a critical synthesis of current knowledge on TRWP generation mechanisms, influenced by tyre composition, road types, and vehicle operation, and their environmental dispersion through air, stormwater runoff, snow removal, and roadside deposition. The chemical and physical complexity of TRWPs—often composed of rubber, bitumen, road paint, and heavy metals—necessitates multifaceted analytical approaches. We synthesise current advancements in TRWP identification techniques, including microscopy, micro-spectroscopy, and thermal desorption methods, while benchmarking their applicability using ISO standards. Furthermore, we develop an integrated framework synthesising current classification schemes, detection strategies, and regional policy responses for TRWP assessment. By identifying analytical and regulatory gaps, this review highlights the need for harmonised methodologies, improved analytical comparability, and coordinated policy interventions to address the environmental and health implications of TRWPs. Full article