Search Results (2,668)

Plant-parasitic nematodes and insect pests critically threaten agricultural productivity, but chemical pesticides face limitations due to resistance and environmental concerns, necessitating eco-friendly biopesticides targeting both pests and nematodes. Here, we developed a high-throughput screening platform using Caenorhabditis elegans to identify entomopathogenic fungi exhibiting nematocidal activity against Meloidogyne incognita. Among 32 tested strains, nine Metarhizium spp. and one Beauveria strain demonstrated dual efficacy against C. elegans and M. incognita. Metarhizium anisopliae CQMa421 showed the highest virulence, suppressing nematode reproduction by 42.7% and inducing >80% mortality. Pot experiments revealed a 50% reduction in the root galling index and 50.3% fewer root galls in Solanum lycopersicum. The CQMa421 filtrate caused irreversible locomotor deficits and reduced egg hatching rates by 28%. Concurrently, intestinal damage, elevated oxidative stress and autophagy were observed in C. elegans. This was accompanied by a transcriptome-wide modulation of genes involved in detoxification and immune defense pathways. These findings demonstrate the efficacy of our C. elegans-based screening method for identifying fungi with nematocidal potential. CQMa421’s virulence against M. incognita suggests its promise for pest management, while molecular insights highlight pathways that may contribute to the future design of future nematicides. This study advances fungal biocontrol agents and offers a sustainable strategy for agriculture. Full article

Highway service area pavements are exposed to severe conditions such as heavy traffic, oil infiltration, and temperature fluctuations, which lead to issues like rutting and cracking in conventional asphalt mixtures. Although warm mix epoxy asphalt mixtures have high strength and corrosion resistance, their high epoxy content and stringent construction requirements limit their engineering applications. To address these challenges, a design and construction method for warm mix epoxy asphalt mixtures with low epoxy content (≤20%) was proposed. The mineral aggregate gradation was optimized using the CAVF volumetric method, and the impact of different epoxy asphalt-aggregate ratios was analyzed through various performance tests, including Marshall stability, high-temperature stability, low-temperature bending, and oil resistance tests. The construction available time was determined using viscosity tests, and process parameters were optimized based on infrared thermography and real-time compaction monitoring. The results show that a 5.4% epoxy asphalt-aggregate ratio yields the best overall performance, with significantly better dynamic stability, tensile strain, and oil resistance compared to SBS-modified asphalt mixtures. The recommended construction parameters, including temperature control and compaction process, ensure optimal performance and durability. The proposed methods provide essential technical support for the effective application of warm mix epoxy asphalt in service area pavements. Full article

Industrial workers often engage in repetitive lifting tasks. This type of continual loading on their arms throughout the workday can lead to muscle or tendon injuries. A non-intrusive system designed to assist a worker’s arms would help alleviate strain on their muscles, thereby preventing injury and minimizing productivity losses. The goal of this project is to develop a wearable soft robotic arm enhancement device that supports a worker’s muscles by sharing the load during lifting tasks, thereby increasing their lifting capacity, reducing fatigue, and improving their endurance to help prevent injury. The device should be easy to use and wear, functioning in relative harmony with the user’s own muscles. It should not restrict the user’s range of motion or flexibility. The human arm consists of numerous muscles that work together to enable its movement. However, as a proof of concept, this project focuses on developing a prototype to enhance the biceps brachii muscle, the primary muscle involved in pulling movements during lifting. Key components of the prototype include a soft robotic muscle or actuator analogous to the biceps, a control system for the pneumatic muscle actuator, and a method for securing the soft muscle to the user’s arm. The McKibben-inspired pneumatic muscle was chosen as the soft actuator for the prototype. A hybrid control algorithm, incorporating PID and model-based control methods, was developed. Electromyography (EMG) and pressure sensors were utilized as inputs for the control algorithms. This paper discusses the design strategies for the device and the preliminary results of the feasibility testing. Based on the results, a wearable EMG-controlled soft robotic arm augmentation could effectively enhance the endurance of industrial workers engaged in repetitive lifting tasks. Full article

Springs are widely used in industries such as aerospace and automotive. As the demand for emission reduction grows, the research on lightweight spring performance is becoming increasingly important. This study analyses the mechanical performance of triple-layer braided composite helical springs (TCHS) under various loads and compression angles. Firstly, the optimal high-temperature curing condition of the epoxy resin was determined through tensile and three-point bending analysis. Then, TCHS were fabricated based on optimal epoxy curing conditions, and multi-angle compression tests under different loads were carried out. Simultaneously, strain gauges were installed at various positions and orientations on the inner and outer sides of the spring wire to reveal strain patterns during the compression. The test results indicate that stiffness decreases with increasing compression angle. Additionally, the strain in the inner and outer positions in different directions of the same region increased with the rise in compression force and angle, and strains in the helical direction were the largest. Subsequently, strain in the helical direction across different regions further showed that maximum strain occurred in the centre coil (region 2), with inner and outer helical direction strains reaching −5116.89 με and 5700.15 με, respectively, which are 71.3% and 90.4% higher than those in region 1 and 73.2% and 92.9% higher than those in region 3. As the compression load increased, cracks appeared on the outer side of the centre coil. In addition, the crack was perpendicular to the helical direction, further confirming that the highest strain occurred in the helical direction. This study provides an in-depth analysis of the impact of angle-specific loads on TCHS, offering valuable insights for the design and optimisation of composite helical springs and laying a theoretical foundation for their future development. Full article

Expansive soils have significant characteristics of expansion by water absorption, contraction by water loss. Under the freeze–thaw (F-T) cycles, the engineering diseases are more significant, and the serious geotechnical engineering incidents are induced extremely easily. The aim is to investigate the mechanical response characteristics of geogrid-reinforced expansive soils (GRES) under F-T cycles. Based on a series of large-scale temperature-controlled triaxial tests, influencing factors were considered, such as the number of F-T cycles, the geogrid layers, and the confining pressure. The results showed that: (1) Friction between the expansive soil and geogrid and the geogrid’s embedded locking effect indirectly provided additional pressure, limited shear deformation. With the increase in reinforced layers, the stress–strain curve changed from a strain-softening to a strain-hardening type. (2) Elastic modulus, cohesion, and friction angle decreased significantly with increasing number of F-T cycles, whereas dynamic equilibrium was reached after six F-T cycles. (3) The three-layer reinforced specimens showed the best performance of F-T resistance, compared to the plain soil, the elastic modulus reduction amount decreases from 35.7% to 18.3%, cohesion from 24.5% to 14.3%, and friction angle from 7.6% to 4.5%. (4) A modified Duncan–Zhang model with the confining pressure, the F-T cycles, and the geogrid layers was proposed; the predicted values agreed with the measured values by more than 90%, which can be used as a prediction formula for the stress–strain characteristics of GRES under freeze–thaw cycling conditions. The research results can provide important theoretical support for the practical engineering design of GRES in cold regions. Full article

Bacterial communities in diverse environmental niches respond to various external stimuli for survival. A primary means of communication between bacterial cells involves one-component (OC) and two-component signal transduction systems (TCSs). These systems are key for sensing environmental changes and regulating bacterial physiology. TCSs, which are the more complex of the two, consist of a sensor histidine kinase for receiving an external input and a response regulator to convey changes in bacterial cell physiology. For numerous reasons, TCSs have emerged as significant targets for antibacterial drug design due to their role in regulating expression level, bacterial viability, growth, and virulence. Diverse studies have shown the molecular mechanisms by which TCSs regulate virulence and antibiotic resistance in pathogenic bacteria. In this study, we performed a thorough analysis of the data from multiple public databases to assemble a comprehensive catalog of the principal detection systems present in both the non-pathogenic Pseudomonas putida KT2440 and the pathogenic Pseudomonas aeruginosa PAO1 strains. Additionally, we conducted a sequence analysis of regulatory elements associated with transcriptional proteins. These were classified into regulatory families based on Helix-turn-Helix (HTH) protein domain information, a common structural motif for DNA-binding proteins. Moreover, we highlight the function of bacterial TCSs and their involvement in functions essential for bacterial survival and virulence. This comparison aims to identify novel targets that can be exploited for the development of advanced biotherapeutic strategies, potentially leading to new treatments for bacterial infections. Full article

This paper focuses on the mathematical and numerical modeling of a non-classical macro fiber composite (MFC) piezoelectric transducer, MFC-P2, integrated with an aluminum cantilever beam for energy harvesting applications. It seeks to harness the transverse vibration energy in the environment to power small electronic devices, such as wireless sensors, where conventional power sources are inconvenient. The P2-type macro fiber composites (MFC-P2) are specifically designed for transverse energy harvesting applications. They offer high electric source capacitance and improved electric charge generation due to the strain developed perpendicularly to the voltage produced. The system is modeled analytically using Euler–Bernoulli beam theory and piezoelectric constitutive equations, capturing the electromechanical coupling in the d31 mode. Numerical simulations are conducted using COMSOL Multiphysics 6.29 to reduce the complexity of the mathematical model and analyze the effects of material properties, geometric configurations, and excitation conditions. The theoretical model is based on the transverse vibrations of a cantilevered beam using Euler–Bernoulli theory. The natural frequencies and mode shapes for the first four are determined. Depending on these, the resonance frequency, voltage, and power outputs are evaluated across a 12 kΩ resistive load. The results demonstrate that the energy harvester effectively operates near its fundamental resonant frequency of 10.78 Hz, achieving the highest output voltage of approximately 0.1952 V and a maximum power output of 0.0031 mW. The generated power is sufficient to drive ultra-low-power devices, validating the viability of MFC-based cantilever structures for autonomous energy harvesting systems. The application of piezoelectric phenomena and obtaining electrical energy from mechanical vibrations can be powerful solutions in such systems. The application of piezoelectric phenomena to convert mechanical vibrations into electrical energy presents a promising solution for self-powered mechatronic systems, enabling energy autonomy in embedded sensors, as well as being used for structural health monitoring applications. Full article

Background/Objectives: Lower limb amputation profoundly affects individuals and their family caregivers, particularly during home transition after hospital discharge. Understanding the needs, challenges, and emotions during this period is essential for designing effective family centered empowerment interventions. This study aimed to explore the lived experiences of amputees and their caregivers, identify their needs and challenges, and identify strategies to foster empowerment, resilience, and adaptation after amputation. Methods: This qualitative, descriptive-exploratory study involved semi-structured interviews with 37 dyads, each comprising an amputee who has undergone major dysvascular lower limb amputation and their primary caregiver, who provided home care. The participants attended follow-up consultations post-amputation. Data were collected over a 13-month period and analyzed using qualitative content analysis based on Bardin’s methodology, with support from ATLAS.ti 23.3.4 software for coding and data organization. Results: Four categories emerged: (i) difficulties faced, including loss of autonomy, mobility challenges, architectural barriers, and emotional strain; (ii) home discharge, emphasizing functional training for amputees and caregivers and the need for community support; (iii) impact of amputation, highlighting acceptance difficulties, psychological distress, social isolation, and lifestyle changes; and (iv) empowerment strategies, focusing on psychological support, skills training, assistive devices, and coordinated care. Tailored interventions such as peer support, home adaptations, and multidisciplinary care are essential for resilience, independence, and improved quality of life. Conclusions: Family centered empowerment strategies are vital for improving the outcomes of amputees and caregivers. Interventions that prioritize caregiver education, psychological support, and enhanced accessibility promote resilience, autonomy, and quality of life. These findings highlight the need for integrated hospital-to-community programs. Full article

This study proposes an innovative design strategy for molybdenum disulfide (MoS₂) optoelectronic devices based on three-dimensional folded configurations. A “Z”-shaped folded MoS₂ device was fabricated through mechanical exfoliation combined with a pre-strain technique on elastic substrates. Experimental investigations reveal that the geometric folding deformation induces novel photocurrent response zones near folded regions beyond the Schottky junction area via band structure reconstruction, achieving triple polarity switching (negative–positive–negative–positive) of photocurrent. This breakthrough overcomes the single-polarity separation mechanism limitation in conventional planar devices. Scanning photocurrent microscopy demonstrates a 40-fold enhancement in photocurrent intensity at folded regions compared to flat areas, attributed to the optimization of carrier separation efficiency through a pn junction-like built-in electric field induced by the three-dimensional configuration. Voltage-modulation experiments show that negative bias (−150 mV) expands positive response regions, while +200 mV bias induces a global negative response, revealing a dynamic synergy between folding deformation and electric field regulation. Theoretical analysis identifies that the band bending and built-in electric field in folded regions constitutes the physical origin of multiple polarity reversals. This work establishes a design paradigm integrating “geometric deformation-band engineering” for regulating optoelectronic properties of two-dimensional materials, demonstrating significant application potential in programmable photoelectric sensing and neuromorphic devices. Full article

This study investigates the impact of modeling the aluminum (Al) metallization layer as an integrated part of the chip model, versus as an individual component, on the results of electrical–thermal analysis of power semiconductor packages using Finite Element Analysis (FEA), ANSYS 2024 R2. The results showed that modeling the aluminum metallization layer separately exhibited high consistency with actual thermal imaging data. Furthermore, based on these findings, we observed through simulations that the aluminum metallization layer plays a key role in improving the uniformity of current density and temperature distribution within the chip. Using the aluminum metallization layer model, we optimized the thickness, material, and design of the metallization layer, as well as the bonding wire material through the design of experiments (DOE) methodology. Under the optimized conditions, an optimal design is proposed to minimize the voltage–current ratio (V_DS/I_DS), maximum junction temperature, strain, and von Mises stress. This study systematically examines the influence of aluminum metallization layer modeling on FEA-based power semiconductor package simulations and is expected to serve as a valuable reference for future power device design utilizing finite element analysis. Full article

The rapidly evolving field of functional yarns has garnered substantial research attention due to their exceptional potential in enabling next-generation electronic textiles for wearable health monitoring, human–machine interfaces, and soft robotics. Despite notable advancements, the development of yarn-based strain sensors that simultaneously achieve high flexibility, stretchability, superior comfort, extended operational stability, and exceptional electrical performance remains a critical challenge, hindered by material limitations and structural design constraints. Here, we present a bioinspired, hierarchically structured core-sheath yarn sensor (CSSYS) engineered through an efficient dip-coating process, which synergistically integrates the two-dimensional conductive MXene nanosheets and one-dimensional silver nanowires (AgNWs). Furthermore, the sensor is encapsulated using a yarn-based protective layer, which not only preserves its inherent flexibility and wearability but also effectively mitigates oxidative degradation of the sensitive materials, thereby significantly enhancing long-term durability. Drawing inspiration from the natural architecture of plant stems—where the inner core provides structural integrity while a flexible outer sheath ensures adaptive protection—the CSSYS exhibits outstanding mechanical and electrical performance, including an ultralow strain detection limit (0.05%), an ultrahigh gauge factor (up to 744.45), rapid response kinetics (80 ms), a broad sensing range (0–230% strain), and exceptional cyclic stability (>20,000 cycles). These remarkable characteristics enable the CSSYS to precisely capture a broad spectrum of physiological signals, ranging from subtle arterial pulsations and respiratory rhythms to large-scale joint movements, demonstrating its immense potential for next-generation wearable health monitoring systems. Full article

The mechanical properties of metals produced by Wire Arc Additive Manufacturing (WAAM) differ significantly from those of rolled sheets due to their cast-like structure and repeated thermal cycling. This study aims to develop a predictive model capable of accurately estimating the stress–strain behavior of deposited metal based on process parameters. To achieve this, a series of experiments were conducted, and test specimens were produced. Arc current and deposition rate were selected as factors in a quasi-D-optimal experimental design. Tensile test data were analyzed using the least squares method, resulting in the derivation of regression equations that relate the stress–strain characteristics to the deposition parameters. To verify that the location of specimen extraction does not influence the test results, both thermal modeling and metallographic analysis were employed. Three key findings were established: (1) Thermal simulations and metallographic observations indicate that after the deposition of the first 5–6 layers, the microstructure becomes relatively similar; (2) significant microstructural variation occurs only in the final layer; and (3) six new regression equations were developed to predict the mechanical properties of the deposited metal based on WAAM process parameters. Full article

Helmets are crucial for protecting motorcycle riders from head injuries in accidents. This study proposes a helmet pad design based on a negative-Poisson’s-ratio (NPR) structure and comprehensively evaluates its protective effect on head injuries. A concave hexagonal honeycomb structure was embedded into the energy-absorbing lining of a motorcycle helmet, and finite element collision simulations were conducted according to the ECE R22.05 standard. These simulations compared and analyzed the differences in protective performance between concave hexagonal honeycomb helmets with different parameter configurations and traditional expanded polystyrene (EPS) helmets under flat anvil impact scenarios. Using biomechanical parameters, including peak linear acceleration (PLA), head injury criterion (HIC), intracranial pressure (ICP), maximum principal strain (MPS), and the probability of AIS2+ traumatic brain injury, the protective effect of the helmets on traumatic brain injury was evaluated. The results showed that when the wall angle of the honeycomb structure was 60°, honeycomb helmets with wall thicknesses of 0.8 mm and 1.0 mm significantly reduced PLA and HIC values. In particular, the honeycomb helmet with a wall thickness of 1.0 mm reduced ICP by 25.7%, while the honeycomb helmet with a wall thickness of 1.2 mm exhibited the lowest maximum principal strain in the skull compared to EPS helmets and reduced the probability of AIS2+ brain injury by 7.2%. Concave hexagonal honeycomb helmets demonstrated an excellent protective performance in reducing the risk of traumatic brain injury. These findings provide important theoretical foundations and engineering references for the design and optimization of new protective helmets. Full article

This study presents a proof-of-concept evaluation of optimized whole-cell biosensors designed for the real-time detection of crop infections. Genetically engineered luminescent bacterial strains were used to detect volatile organic compounds (VOCs) emitted by crops during spoilage. Key factors investigated include bacterial uniformity, nutrient supply, and temperature effects. The results demonstrated that lower temperatures (+4 °C) yielded higher sensor sensitivity and prolonged bacterial viability. A proof-of-concept evaluation was conducted in storage-like conditions, showing effective infection detection in potatoes. These findings underscore the potential of whole-cell-based biosensors for monitoring postharvest production in cold storage environments. Full article

Tomato leaf curl Palampur virus (ToLCPalV) is an economically important bipartite begomovirus in the agro-ecological regions in south and western Asia. This study was designed to investigate the sequence variation dynamics, regional delineation, genetic diversity, population structure, and cross-border dispersal patterns of ToLCPalV. The research revealed clear geographical structuring, with distinct Indo–Pak subcontinent and Middle Eastern clades, but no host-specific differentiation. Genetic diversity analysis indicated higher diversity in the Indo–Pak subcontinent, particularly in the DNA-B component, suggesting an older, more diverse population of ToLCPalV prevailing in this region. Neutrality tests and selection pressure analyses revealed predominantly purifying selection, with limited positive selection observed in BV1 of DNA-B. The primary source of dispersal of ToLCPalV progenitor was estimated in Varnasi, India in 1955, from where the virus was spread. No recombination events were detected, suggesting that mutation and selection are the primary drivers of ToLCPalV evolution. Furthermore, a detailed SDT-based nucleotide sequence comparison analysis also identified two potential strains of ToLCPalV. This study elucidates the spatiotemporal dynamics and evolutionary history of ToLCPalV, revealing its cross-border spread and adaptive evolution. These findings contribute to a more comprehensive understanding of begomovirus epidemiology and provide valuable insights into ToLCPalV’s phylogeography and evolutionary dynamics. Full article