Search Results (59,172)

Cadmium (Cd) pollution poses an important problem, but limited information is available about the toxicology effects of Cd on freshwater invertebrates. We investigated the accumulation, oxidative stress, microbial community changes, and transcriptomic alterations in apple snails (Pomacea canaliculata) under Cd stress. The snails were exposed to the 10 μg/L Cd solution for 16 days, followed by a 16-day elimination period. Our results showed that the liver accumulated the highest Cd concentration (17.41 μg/g), followed by the kidneys (8.00 μg/g) and intestine-stomach (6.68 μg/g), highlighting these tissues as primary targets for Cd accumulation. During the elimination period, Cd concentrations decreased in all tissues, with the head-foot and shell exhibiting over 30% elimination rates. Cd stress also resulted in reduced activities of superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) compared to the control group. Notably, even after 16 days of depuration, the enzyme activities did not return to normal levels, indicating persistent toxicological effects. Cd exposure significantly reduced the diversity of gut microbiota in P. canaliculata. Moreover, transcriptome analysis identified differentially expressed genes (DEGs) primarily associated with lysosome function, motor proteins, protein processing in the endoplasmic reticulum, drug metabolism via cytochrome P450 (CYP450), arachidonic acid metabolism, and ECM–receptor interactions. These findings suggest that Cd stress predominantly disrupts cellular transport and metabolic processes. Overall, our study provides comprehensive insights into the toxicological impact of Cd on P. canaliculata and emphasizes the importance of understanding the mechanisms underlying Cd toxicity in aquatic organisms. Full article

This study evaluates the chemical, physical, mechanical, and biological properties of untreated and heat-treated Cryptomeria japonica (Thunb ex L.f.) D.Don wood from the Azores, Portugal. Heat treatment was performed at 212 °C for 2 h following the Thermo-D class protocol. Chemical analysis revealed an increase in ethanol soluble extractives and lignin content after heat treatment, attributed to hemicellulose degradation and condensation reactions. Dimensional stability improved significantly, as indicated by reduced swelling coefficients and higher anti-swelling efficiency (ASE), particularly in the tangential direction. Heat-treated wood demonstrated reduced water absorption and swelling, enhancing its suitability for applications requiring dimensional stability. Mechanical tests showed a decrease in bending strength by 19.6% but an increase in the modulus of elasticity (MOE) by 49%, reflecting changes in the wood’s structural integrity. Surface analysis revealed significant color changes, with darkening, reddening, and yellowing, aligning with trends observed in other heat-treated woods. Biological durability tests indicated that both untreated and treated samples were susceptible to subterranean termite attack, although heat-treated wood exhibited a higher termite mortality rate, suggesting potential long-term advantages. This study highlights the impact of heat treatment on Cryptomeria japonica wood, emphasizing its potential for enhanced stability and durability in various applications. Full article

Pedestrian comfort is not only related to the health of the human body, but also directly impacts the efficiency and lifespan of building materials. Raised floors have more complex geometric characteristics and structural dynamic properties compared to traditional flooring, which necessitates an analysis of pedestrian comfort. This study explores four different configurations of raised floors in prefab bathroom units to evaluate their pedestrian comfort. Through theoretical and experimental modal analysis, the natural frequencies and potential deformation areas are identified, enabling the calculation of peak acceleration of the raised floors under walking excitation. The study then quantitatively assesses the pedestrian comfort of raised floors based on natural frequency and peak acceleration measurements, proposing an optimization design method using a multi-island genetic algorithm (MIGA). By adjusting parameters such as the support leg distance, beam shape, and support board surface layer thickness, an optimal balance between pedestrian comfort and heat transfer performance is achieved. Through the integration of simulation and experimental techniques, the study presents an efficient and cost-effective optimization design method for raised floors and explores the impact mechanism between design variables and pedestrian comfort performance. Full article

The fig (the syconium of the Ficus tree) and its pollinating fig wasp represent exceptional examples for researching plant–insect interactions due to their remarkable specificity in species interaction and mutually beneficial symbiotic relationship. However, the mechanisms underlying the developmental process of monoecious figs in response to the entry of pollinating fig wasps (pollinators) and the metabolic changes occurring during this process remain elusive. Our study employed a combination of controlled experiments in the field and LC-MS methods to investigate the impact of pollinating fig wasp entry on the developmental phase of figs, as well as the metabolic alterations occurring during this process. A total of 381 metabolites and 155 differential metabolites were identified, with the predominant classes of metabolites being organic acids, lipids, and benzene aromatic compounds. The results suggest that in the absence of wasp entry, the receptive phase of fig would exhibit an extended duration. However, upon the entry of fig wasps, the receptive phase of figs would terminate within a span of 1 to 2 days, concomitant with substantial fluctuations in the composition and proportions of metabolites within the fig. Our research focuses on the analysis of linoleic acid metabolism, phenylpropanoid biosynthesis, and flavonoid biosynthesis pathways. Our findings suggest that the entry of wasps triggers alterations in the metabolic regulatory mechanisms of figs. Prior to wasp entry, metabolites primarily regulate fig growth and development. However, after wasp entry, metabolites predominantly govern lipid accumulation and the establishment of defense mechanisms, indicating a transition in fig development. This metabolic perspective explains why figs promptly enter an interflower phase that is not attractive to pollinating fig wasps after their entry, and how figs achieve reproductive balance through the regulation of different metabolic pathways. This study provides scientific evidence for elucidating the stability mechanism of the fig wasp mutualistic system. Full article

To overcome limitations of dentin bonding due to collagen degradation at a bonded interface, incorporating bioactive glass (BAG) into dentin adhesives has been proposed to enhance remineralization and improve bonding durability. This study evaluated sol–gel-derived BAGs (BAG79, BAG87, BAG91, and BAG79F) and conventional melt-quenched BAG (BAG45) incorporated into dentin adhesive to assess their remineralization and mechanical properties. The BAGs were characterized by using field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy for surface morphology. The surface area was measured by the Brunauer–Emmett–Teller method. X-ray diffraction (XRD) analysis was performed to determine the crystalline structure of the BAGs. Adhesive surface analysis was performed after approximating each experimental dentin adhesive and demineralized dentin by using FE-SEM. The elastic modulus of the treated dentin was measured after BAG-containing dentin adhesive application. The sol–gel-derived BAGs exhibited larger surface areas (by 400–600 times) than conventional BAG, with BAG87 displaying the largest surface area. XRD analysis indicated more pronounced and rapid formation of hydroxyapatite in the sol–gel BAGs. Dentin with BAG87-containing adhesive exhibited the highest elastic modulus. The incorporation of sol–gel-derived BAGs, especially BAG87, into dentin adhesives enhances the remineralization and mechanical properties of adhesive–dentin interfaces. Full article

The automotive industry is responsible for about 20% of greenhouse gas emissions in Europe, and it is under notable pressure to meet the reduction targets set by the European Union for the next decades. In this context, lightweighting is a very effective design strategy for which materials selection plays a key role. One of the main challenges of lightweighting is selecting materials with enhanced structural properties but a reduced weight in comparison with traditional solutions. The spectrum of available materials is very large, and the choice needs to be carefully evaluated based on multiple factors, such as mechanical behavior, raw materials cost, the availability of manufacturing processes, and environmental impact. This article presents an innovative methodology for materials selection in the lightweight automotive field based on the Ashby approach for mechanical performance coefficients as an initial filtering criterion. Following this preliminary screening, this study adopts the VIKOR (Vise Kriterijumska Optimizacija I Kompromisno Resenje) MCDA (Multi-Criteria Decision Analysis) technique to rank feasible design solutions based on case study boundary conditions. The evaluation criterion of different design options encompasses crucial factors, such as mechanical properties, cost considerations, and environmental impact measures. The method is finally validated by the application of a redesign case study, a motor bracket of an electric commercial car. Full article

In disaster-stricken areas, rapid restoration of communication infrastructure is critical to ensuring effective emergency response and recovery. Swarm UAVs, operating as mobile aerial base stations (MABS), offer a transformative solution for bridging connectivity gaps in environments where the traditional infrastructure has been compromised. This paper presents a novel hybrid path planning approach combining affinity propagation clustering (APC) with genetic algorithms (GA), aimed at maximizing coverage, and ensuring quality of service (QoS) compliance across diverse environmental conditions. Comprehensive simulations conducted in suburban, urban, dense urban, and high-rise urban environments demonstrated the efficacy of the APC-GA approach. The proposed method achieved up to 100% coverage in suburban settings with only eight unmanned aerial vehicle (UAV) swarms, and maintained superior performance in dense and high-rise urban environments, achieving 97% and 93% coverage, respectively, with 10 UAV swarms. The QoS compliance reached 98%, outperforming benchmarks such as GA (94%), PSO (90%), and ACO (88%). The solution exhibited significant stability, maintaining consistently high performance, highlighting its robustness under dynamic disaster scenarios. Mobility model analysis further underscores the adaptability of the proposed approach. The reference point group mobility (RPGM) model consistently achieved higher coverage rates (95%) than the random waypoint model (RWPM) (90%), thereby demonstrating the importance of group-based mobility patterns in enhancing UAV deployment efficiency. The findings reveal that the APC-GA adaptive clustering and path planning mechanisms effectively navigate propagation challenges, interference, and non-line-of-sight (NLOS) conditions, ensuring reliable connectivity in the most demanding environments. This research establishes the APC-GA hybrid as a scalable and QoS-compliant solution for UAV deployment in disaster response scenarios. By dynamically adapting to environmental complexities and user mobility patterns, it advances state-of-the-art emergency communication systems, offering a robust framework for real-world applications in disaster resilience and recovery. Full article

Despite decades of extensive studies, the mechanism of concrete creep remains a subject of debate, mainly due to the complex nature of cement microstructure. This complexity is further amplified by the interplay between water and the cement microstructure. The present study aimed to better understand the creep mechanism through creep tests on microprisms of cement paste at hygral equilibrium. First, microprisms with dimensions of 150 mm × 150 mm × 300 mm were prepared by precision cutting from a cement paste specimen with a water-to-cement ratio of 0.4. Subsequently, uniaxial compression and creep tests were carried out on these microprisms in a chamber with controlled relative humidity (RH). To mitigate the impact of plasticity and damage, the applied peak load was set to generate a stress level that was approximately 40% of the compressive strength. Moreover, an analytical coefficient $\phi$ was formulated to account for the foundation effect on microprism creep, agreeing with the numerical analysis employing the finite element method. Our findings showed that the microscale creep compliance varied when the RH level was changed from 90% to 11%. Furthermore, logarithmic and power-law models were both applied to simulate creep curves. Lastly, the modeled creep behaviors were compared with those obtained by microindentation experiments in previous studies. Full article

This study investigates the unsteady aerodynamic mechanisms underlying the efficient flight of birds and proposes a biomimetic flapping-wing aircraft design utilizing a double-crank double-rocker mechanism. Building upon a detailed analysis of avian flight dynamics, a two-stage foldable flapping mechanism was developed, integrating an optimized double-crank double-rocker structure with a secondary linkage system. This design enables synchronized wing flapping and spanwise folding, significantly enhancing aerodynamic efficiency and dynamic performance. The system’s planar symmetric layout and high-ratio reduction gear configuration ensure movement synchronicity and stability while reducing mechanical wear and energy consumption. Through precise modeling, the motion trajectories of the inner and outer wing segments were derived, providing a robust mathematical foundation for motion control and optimization. Computational simulations based on trajectory equations successfully demonstrated the characteristic figure-eight wingtip motion. Using 3D simulations and CFD analysis, key parameters—including initial angle of attack, aspect ratio, flapping frequency, and flapping speed—were optimized. The results indicate that optimal aerodynamic performance is achieved at an initial angle of attack of 9°, an aspect ratio of 5.1, and a flapping frequency and speed of 4–5 Hz and 4–5 m/s, respectively. These findings underscore the potential of biomimetic flapping-wing aircraft in applications such as UAVs and military technology, providing a solid theoretical foundation for future advancements in this field. Full article

Yeasts produce numerous antimicrobial agents such as killer toxins, volatile organic compounds (VOCs), and other secondary metabolites, establishing themselves in developing natural and sustainable biocontrol strategies for agriculture and food preservation. This study addressed the biocontrol potential of yeasts, isolated from spontaneous fermentations of rosehips (Rosa canina L.) and rowanberries (Sorbus aucuparia L.), focusing on their killer phenotypes and VOCs production. Yeasts were isolated using spontaneous fermentations with Hanseniaspora uvarum and Metschnikowia pulcherrima identified as the dominant species, comprising approximately 70% of the yeast population. Among 163 isolated strains, 20% demonstrated killing activity, with Saccharomyces cerevisiae exhibiting the strongest killing efficiency, as well as Pichia anomala and M. pulcherrima showing broad-spectrum antagonistic activity. This study identified dsRNA-encoded killer phenotypes in S. cerevisiae, S. paradoxus, and Torulaspora delbrueckii, revealing multiple distinct killer toxin types. The biocontrol potential of wild berry-inhabiting yeasts was demonstrated in a real food system, grape juice, where the S. cerevisiae K2-type killer strain significantly reduced fungal contaminants. The selected H. uvarum, M. pulcherrima, S. cerevisiae, and S. paradoxus yeast strains representing both berries were applied for VOC analysis and identification by gas chromatography-linked mass spectrometry. It was revealed that the patterns of emitted volatiles are yeast species-specific. Statistically significant differences between the individual VOCs were observed among killing phenotype-possessing vs. non-killer S. paradoxus yeasts, thus revealing the involvement of killer systems in multi-level biocontrol enablement. The performed studies deepen our understanding of potential yeast biocontrol mechanisms, highlight the importance of produced antimicrobials and volatiles in ensuring antagonistic efficacy, and prove the relevance of isolated biocontrol yeasts for improving food safety. Full article

The innate immune response serves as the primary defense against viral infections, with the recognition of viral nucleic acids by pattern recognition receptors (PRRs) initiating antiviral responses. Mitochondrial antiviral-signaling protein (MAVS) acts as a pivotal adaptor protein in the RIG-I pathway. Alternative splicing further diversifies MAVS isoforms. In this study, we identified and characterized a novel rat MAVS variant (MAVS500) with a twenty-one-nucleotide deletion, resulting in a protein seven amino acids shorter than the wild-type (WT) rat MAVS. The MAVS500 was cloned from the rat bladder cancer cell line, NBT-II, using specific primers, and subsequently sequenced. MAVS500 was overexpressed in HEK293T and NBT-II cells and then analyzed using Western Blotting and fluorescence microscopy. MAVS500 overexpression increased downstream signaling proteins, NFκβ and pNFκβ, compared to WT rat MAVS in both human and rat cell lines. Structural analysis revealed a high similarity between MAVS500 and WT rat MAVS. The seven-amino-acid deletion in MAVS500 induces significant conformational rearrangements, reducing helical turns and altering structural dynamics, which may impact its interactions with downstream signaling molecules in the innate immune pathway. The identification of MAVS500 enhances our understanding of MAVS regulation and its role in the innate immune response, providing valuable insights into alternative splicing as a mechanism for diversifying protein function. Full article

Bee venom (BV) and its main compound melittin (MLT) have antioxidant, anti-inflammatory, and anti-aging activities; however, very little research has been conducted on their effects on skin aging. In this study, a mouse skin aging model induced by D-galactose was constructed via subcutaneous injection into the scruff of the neck, and different doses of BV and MLT were used as interventions. The anti-aging effects and mechanisms of BV and MLT were explored by detecting the skin morphology and structure, and anti-aging-related factors and performing non-targeted metabolomics of mice. BV and MLT improved dermal and epidermal thickness, boosted the collagen fiber content, increased hydroxyproline and hyaluronic acid levels, and enhanced transcript-level expression of IL-10, Col1a1, and Col3a1, while decreasing that of IL-1β. Metabolomic analysis showed that BV and MLT regulated the levels of some metabolites (compared to those in the skin aging control). BV effectively alleviated skin aging by regulating the pentose phosphate pathway, and pathways associated with carbon, galactose, and β-alanine metabolism, whereas MLT regulated pathways related to lipid metabolism, cholesterol metabolism, and atherosclerosis. This study highlights the potential applicability of BV and MLT in skin aging treatments and cosmetic products. Full article

Tomato, as the vegetable queen, is cultivated worldwide due to its rich nutrient content and unique flavor. Nondestructive technology provides efficient and noninvasive solutions for the quality assessment of tomatoes. However, processing the substantial datasets to achieve a robust model and enhance detection performance for nondestructive technology is a great challenge until deep learning is developed. The aim of this paper is to provide a systematical overview of the principles and application for three categories of nondestructive detection techniques based on mechanical characterization, electromagnetic characterization, as well as electrochemical sensors. Tomato quality assessment is analyzed, and the characteristics of different nondestructive techniques are compared. Various data analysis methods based on deep learning are explored and the applications in tomato assessment using nondestructive techniques with deep learning are also summarized. Limitations and future expectations for the quality assessment of the tomato industry by nondestructive techniques along with deep learning are discussed. The ongoing advancements in optical equipment and deep learning methods lead to a promising outlook for the application in the tomato industry and agricultural engineering. Full article

This research study investigated the production and properties of zinc oxide (ZnO) nanoparticles derived from corn husks and their priming effects on wheat plant proliferation and antioxidant mechanisms compared to the nutri-priming technique under regular irrigation and drought-stressed conditions. Transmission and scanning electron microscopy (TEM and SEM), energy-dispersive X-ray spectroscopy (EDAX), and X-ray diffraction confirmed the nanoparticles’ hexagonal morphology and typical dimensions of 51 nm. The size and stability of these nanoparticles were assessed through the size distribution and zeta potential analysis, indicating reasonable stability. Fourier-transform infrared spectroscopy (FTIR) detected the newly formed functional groups. This study emphasized the role of reactive oxygen species (ROS) and phenolic compounds in plant responses to nanoparticle treatment, particularly in detoxifying harmful radicals. The research also examined the activity of antioxidant enzymes, including peroxidase (POX), catalase (CAT), and glutathione reductase (GR), in alleviating stress caused by oxidation while subjected to various treatments, including micronutrient seed priming with DR GREEN fertilizer. Some biochemical compounds, such as total phenolics (TPCs), total flavonoids (TFCs), and total hydrolysable sugars, were estimated as well to show the effect of the different treatments on the wheat plants. The findings suggested that ZnO nanoparticles can enhance antioxidant enzyme activity under certain conditions while posing phytotoxic risks, underscoring the complexity of plant–nanoparticle interactions and the potential for improving crop resilience through targeted micronutrient applications. Full article

This study aims to determine the extent to which coating composition and workpiece properties impact machinability and tool selection when turning Compacted Graphite Iron (CGI) under extreme roughing conditions. Two CGI workpieces, differing in pearlite content and graphite nodularity, were machined at a cutting speed of 180 m/min, feed rate of 0.18 mm/rev, and depth of cut of 3 mm. To assess the impact of tool properties across a wide range of commercially available tools, four diverse multilayered cemented carbide tools were evaluated: Tool A and Tool B with a thin AlTiSiN PVD coating, Tool C with a thick Al₂O₃-TiCN CVD coating, and Tool D with a thin Al₂O₃-TiC PVD coating. The machinability of CGI and wear mechanisms were analyzed using pre-cutting characterization, in-process optical microscopy, and post-test SEM analysis. The results revealed that CGI microstructural variations only affected tool life for Tool A, with a 110% increase in tool life between machining CGI Grade B and Grade A, but that the effects were negligible for all other tools. Tool C had a 250% and 70% longer tool life compared to the next best performance (Tool A) for CGI Grade A and CGI Grade B, respectively. With its thick CVD-coating, Tool C consistently outperformed the others due to its superior protection of the flank face and cutting edge under high-stress conditions. The cutting-induced stresses played a more significant role in the tool wear process than minor differences in workpiece microstructure or tool properties, and a thick CVD coating was most effective in addressing the tool wear effects for the extreme roughing conditions. However, differences in tool life for Tool A showed that tool behavior cannot be predicted based on a single system parameter, even for extreme conditions. Instead, tool properties, workpiece properties, cutting conditions, and their interactions should be considered collectively to evaluate the extent that an individual parameter impacts machinability. This research demonstrates that a comprehensive approach such as this can allow for more effective tool selection and thus lead to significant cost savings and more efficient manufacturing operations. Full article