High-quality cardiopulmonary resuscitation (CPR) is fundamental to survival. Standard training emphasizes the lateral position, but confined spaces (e.g., airplane aisles, ambulances, narrow hallways) often necessitate the over-the-head (OTH) technique. The effect of this position on compression biomechanics remains unclear. To compare OTH and standard lateral CPR techniques in a manikin simulation regarding the quality of chest compression and rescuer fatigue. This prospective, crossover simulation study included 45 experienced health care professionals. Participants performed 2 min of continuous chest compressions in both lateral and OTH positions, separated by a 24-h washout period. Compression depth, rate, and fraction were recorded using a CPR feedback-capable defibrillator, with real-time audiovisual feedback disabled during data collection. Fatigue was assessed using a numeric rating scale. A total of 41 participants completed the protocol. The mean compression rate (121.7 vs. 120.5/min, p = 0.306) and mean depth (49.5 vs. 49.5 mm, p = 0.897) were similar between the OTH and lateral positions, indicating comparable average depth adequacy. However, reflecting lower consistency, the percentage of compressions within the target depth range (50-60 mm) was considerably lower in the OTH position (35.2% vs. 49.4%, p = 0.027). Self-reported fatigue scores did not differ considerably (2.5 vs. 2.8, p = 0.132). Although OTH CPR achieved a similar average depth and rate to the lateral position, it resulted in a lower proportion of compressions within the optimal depth range. Therefore, OTH CPR seems to be a feasible situational alternative in confined environments when lateral access is limited. Dedicated training may be needed to optimize depth in the OTH position. © 2026 Elsevier Inc.
The practice of neonatal/pediatric transport medicine continues to advance. Teams have evolved from providing critical care outside tertiary care centers to participating in collaborative research efforts, benchmarking and quality improvement, developing innovative partnerships, and pushing the limits of care provision during interfacility transport. The most recent consensus document on neonatal and pediatric transport medicine was published more than a decade ago. Advancements in the field necessitate the dissemination of new practices in transport medicine. The following manuscript details the current evidence-supported, expert consensus opinions on the practice of neonatal and pediatric transport medicine and recommendations for its future direction.
To address the limited understanding of the aerodynamic characteristics of bird-inspired flapping-wing aircraft across different flight phases and the unclear flow field interaction mechanisms between the wings and tail, this study performs three-dimensional numerical simulations based on a self-developed prototype using ANSYS Fluent and the overset mesh method. The aerodynamic effects of key tail parameters under different flight conditions are quantitatively evaluated, and the mechanisms of bidirectional wing-tail aerodynamic coupling are investigated. The results show that tail twist has a negligible influence on instantaneous lift and thrust during level flight, with a maximum variation of only 0.2 N, but significantly affects the overall aerodynamic moments of the aircraft. When the tail twist angle increases from 15° to 20°, the pitching moment increases by 6%. In contrast, during climbing flight, the tail pitch angle has a pronounced effect on lift and thrust, and its aerodynamic influence depends strongly on the aircraft angle of attack. At an aircraft angle of attack of 15°, the difference between the maximum and minimum cycle-averaged pitching moments reaches 0.2 N·m. Further analysis of vorticity fields and pressure distributions confirms the existence of distinct wing-tail aerodynamic coupling. The tail not only directly modifies the aerodynamic forces and moments acting on the aircraft but also alters the wing-generated flow structures, while the wing wake simultaneously influences the aerodynamic effectiveness of the tail. This bidirectional wing-tail aerodynamic coupling plays a critical role in shaping the aerodynamic response of the aircraft under different flight conditions. These findings clarify the aerodynamic roles of key tail parameters and reveal the underlying flow field interaction mechanisms across different flight phases, providing a theoretical basis for motion-parameter optimization and precise attitude control of bird-inspired flapping-wing aircraft.
The safety risks associated with cyclists at signalized intersections are often analyzed within isolated units, an approach that fails to account for the inherent behavioral dependencies across consecutive intersections. Ignoring such cross-intersection persistence results in a fragmented understanding of cyclist decision-making and hinders the early identification of risky behaviors. This study investigates cyclists' behavioral persistence across consecutive signalized intersections using high-resolution trajectory data collected from unmanned aerial vehicles and roadside cameras. A re-identification (Re-ID) method is applied to match cyclists across intersections, enabling the analysis of individual-level behavioral persistence. Based on this, a downstream intention prediction framework is developed, incorporating upstream behavioral information as behavioral priors. The results show that cyclists' behaviors are not independent across intersections. While aggregate-level analysis reveals moderate associations, individual-level analysis demonstrates clear persistence in behavior, especially for decision-related variables such as crossing decision and rolling behavior. Incorporating upstream behavioral information significantly improves downstream intention prediction, with the largest improvement observed when individual-level behavioral priors are utilized via Re-ID. The findings highlight the importance of modeling cyclist behavior from a corridor-level perspective. By leveraging cross-intersection behavioral persistence, the proposed framework enables earlier and more reliable identification of risky behaviors, providing practical support for proactive traffic safety management at signalized intersections.
The structural, electronic, optical, transport and photocatalytic properties of the BTe/PtS2 vdW heterojunction are investigated by the density functional theory approach. The results reveal that applying the tensile effect can significantly impact the material's properties. The bandgap values of BTe, PtS2 and BTe/PtS2 vdW heterojunction are 1.599 eV, 1.756 eV and 1.19 eV, respectively. The bandgap decreases as the percentage of applied tensile effect increases. Moreover, the photocatalytic water decomposition of BTe/PtS2 vdW heterojunction is significantly broadened in the pH range compared with that of the two monolayers. In conclusion, the BTe/PtS2 vdW heterojunction can be used as an efficient photocatalytic material for optoelectronic devices and photocatalysis.
The transition from aqueous film-forming foam (AFFF) to fluorine-free foams (F3) requires effective decontamination of aircraft rescue and firefighting (ARFF) vehicles to prevent further PFAS releases. Comprehensive, publicly accessible field assessments of PFAS decontamination protocols for ARFF vehicles are sparse. Herein, PFAS decontamination methods were evaluated on AFFF-impacted ARFF vehicles. PFAS removal was assessed using target PFAS analysis and adsorbable organic fluorine (AOF). While initial samples collected and analyzed using target PFAS analysis demonstrated high removal in the initial rinses (up to 84% of the readily removable PFAS fraction in three rinses), subsequent efforts yielded diminishing returns. Notably, the introduction of cleaning solvents failed to meaningfully enhance decontamination efficiency. Post-cleanout assessments revealed significant PFAS rebound after two months, representing ∼40% of the total readily removable PFAS fraction removed during ARFF vehicle decontamination. Samples collected and analyzed for AOF revealed large quantities of fluorinated compounds not captured by target PFAS analytical methods with between 25 and 160 times greater AOF concentrations emanating from the two ARFF vehicles examined. The higher AOF values compared to target PFAS suggests the importance of non-target PFAS analytical techniques for more comprehensive performance evaluation. The findings of this field study demonstrate that the decontamination methods examined were insufficient to achieve complete PFAS removal from the interior surfaces of ARFF vehicles as evident by the significant PFAS rebound observed post-decontamination. Additional work is needed as inadequate ARFF vehicle decontamination may result in the accidental discharge of PFAS into the environment.
This study aims to develop an interpretable dual-layer information fusion framework driven by the Euclidean Consistency Index (ECI) for UAV flight parameter optimization, which integrates a statistically interpretable linear module with a nonlinear learning layer implemented via support vector regression to enhance 3D reconstruction accuracy in traffic accident scenarios. Experiments based on UAV oblique photogrammetry (27 configurations) were conducted to evaluate reconstruction accuracy using elevation error, horizontal error, and distortion anomaly metrics. The results reveal that flight altitude and image overlap exert coupled effects on reconstruction performance. An optimal parameter range is identified as 20-25 m altitude, 80-85% forward overlap, and 70-75% side overlap, achieving centimeter-level accuracy and stable geometric consistency. The high inter-layer agreement (ECI = 0.9133) confirms the robustness of the proposed fusion strategy. Validation in a real-world accident scene offers preliminary support for its practical applicability under similar conditions. Within the tested experimental scope, this framework provides a quantitatively interpretable and operationally stable foundation for UAV flight parameter selection in accident reconstruction.
A transformation-acoustic (TA) design approach for flow-adaptive gradient-index (GRIN) metamaterial liners is presented in this research. This architecture helps reduce broadband noise in the ducts of high-speed jet engines. Starting with a Mach-dependent coordinate mapping, the effective acoustic parameters ρ(x) and c(x) are combined to keep the local impedance approximately constant all along the liner. The resulting TA-GRIN profile ensures adiabatic impedance matching between the freestream and the backing wall, allowing for broadband reflection suppression without excessive damping. To calculate the reflection coefficient in the frequency and Mach-number domains, a transfer-matrix method is developed that incorporates the convective wavenumber correction [Formula: see text] and the complex sound speed [Formula: see text]. Parameter sweeps show the best factor [Formula: see text] and liner length [Formula: see text], indicating strong broadband reflection suppression across the 300-3000 Hz band, particularly for finite Mach numbers (M = 0.2 and 0.4). The results demonstrate that spatial impedance grading, rather than resistive loss, is the primary physical mechanism governing broadband, flow-adaptive noise attenuation in TA-based metamaterial liners. Beyond regulatory noise reduction, the proposed TA-GRIN liner has direct implications for passenger acoustic comfort. In aircraft with tail-mounted engines, such as the McDonnell Douglas MD-80 and DC-9 families, the close proximity of the propulsion system to the fuselage leads to enhanced acoustic coupling and elevated cabin noise levels, particularly in the rear sections. By suppressing internal reflections and mitigating standing-wave formation in aero-ducts, the present design can contribute to reducing duct-transmitted noise and improving the onboard acoustic environment.
An open abdomen (OA) is a critical surgical condition in which the abdominal wall is intentionally left open to prevent or manage intra-abdominal hypertension or abdominal compartment syndrome or facilitate staged re-exploration. Although OA management is well described in surgical literature, the safe transport of patients with an OA-particularly in air medical and critical care transport settings-presents unique challenges that are less frequently addressed. This review summarizes current evidence and best practices for the transport of patients with an OA, focusing on physiologic considerations, temporary abdominal closure (TAC) methods, equipment, monitoring, and emergency management during interfacility transfer. Key elements of OA transport include secure and intact TAC devices, vigilant monitoring of hemodynamic and ventilatory parameters, and preparedness for complications such as vacuum-assisted closure failure, re-elevated intra-abdominal pressure, and hemodynamic decompensation. Coordination between surgical, critical care, and transport teams is essential. The review details the advantages and limitations of TAC options-such as negative pressure wound therapy, Bogotá bags, and Wittmann patches-and outlines practical recommendations for troubleshooting and in-flight stabilization. Transporting patients with an OA requires specialized knowledge of pathophysiology, meticulous preparation, and clear communication among multidisciplinary teams. Establishing standardized protocols and incorporating OA-specific competencies into air medical training can enhance patient safety and outcomes during these complex transfers.
This study presents a flapping-wing micro aerial vehicle designed for three-dimensional trajectory tracking. The design features center-of-gravity-based steering, three actuators, and omits a dedicated yaw actuator, time-varying wingbeat patterns, and high-frequency actuator switching. To investigate the dynamics of the proposed design, a modified nonlinear controllability framework was developed for theoretical analysis, and a series of flight experiments were conducted to validate the analytical results. The analysis indicates that, despite the absence of a dedicated yaw actuator, the yaw torque required for three-dimensional maneuvering arises from center-of-gravity shifts, asymmetric wing aerodynamics, and an intrinsic feedback mechanism that stabilizes the angle difference between vehicle's yaw angle and trajectory rotation angle. Furthermore, the yaw dynamics exhibit nonminimum phase behaviors in response to center-of-gravity movement. Based on these findings, a multi-tier control architecture is proposed to accommodate these unique dynamics for autonomous flight. Experimental results demonstrate that the proposed design can perform three-dimensional trajectory tracking, with attitude errors below 5° and altitude deviations within 10 cm in most cases.
To evaluate the impact of frequently used medical transport helicopters on neonatal physiology and the delivery of in-flight care and to identify the relevant aircraft characteristics. A targeted review of air medical literature, aerospace engineering sources, and manufacturer documentation was performed. The following 10 helicopter models frequently used in neonatal transport were evaluated: UH-60, S-92, AW101 (EH-101), Mi-171, AB412, EC145 (H145), S76, AW139, Bell 430, and AW109. The comparative analysis focused on cabin design, noise and vibration exposure, high-altitude performance, speed and range, power redundancy, and the ability to maintain a thermally stable environment. There is substantial variability among platforms in features relevant to neonatal safety and care delivery. Medium twin-engine helicopters with spacious cabins (eg, AW139, Bell 412, H145, and S-76) offer superior accessibility for patients and equipment and better overall clinical working conditions. Across all models, noise and vibration levels often exceed the recommended exposure limits for neonates. On the basis of these findings, the type of helicopter significantly influences the quality and safety of neonatal transport. Selection should optimally prioritize aircraft that support neonatal physiological stability and clinical intervention needs rather than relying solely on availability or operational logistics. Strong collaboration between medical teams and aviation operators is essential to optimize the transport environment for vulnerable newborns.
Pilots are susceptible to neck injury during carrier-based aircraft arrested landings due to excessive head flexion. This study used a validated multibody head-neck model to examine how tether stiffness and orientation affect the performance of tether-type head-neck restraint systems. Polyester (stiff) and nylon (soft) tethers were evaluated at four sagittal-plane orientations. Results showed that the presence of a tether significantly reduced peak neck muscle force. Stiff tethers generally provided better restraint, while soft tethers showed slightly lower upper-cervical injury indices. No significant cervical injury was predicted in any condition. These findings can inform future restraint-system design.
This study examined PFAS persistence on plumbing components obtained from a retired aircraft hangar. The effect of rinse volume and pipe corrosion was investigated to address technical gaps and inform practical solutions for PFAS-impacted fire suppression systems. The components, rinsed with deionized water, included straight pipe sections as well as elbows and proportioners. Solid-phase extraction with HPLC/MS/MS was employed to analyze PFAS in the rinse waters. Straight pipe sections followed trends for PFAS persistence reported in the literature for such sections, and the results for elbows and proportioners, not previously reported, suggested meaningful differences compared to straight sections. Results indicate that a single rinsing cycle consisting of three volumes of deionized water is capable of partially removing PFAS and that the amount of PFAS removed by successive rinses decreases with each rinse. Pre- and post-rinse pipe specimens were analyzed using a scanning electron microscope (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Corrosion of the components impacts desorption, potentially due to a weakly bound layer on the surface and a strongly bound layer interacting with metal oxides. These results inform future research and decontamination protocols needed for remediating firefighting infrastructure contaminated with PFAS.
Long-distance neonatal air transport did not begin in hospitals, but rather in times of crisis, driven by courage, ingenuity, and humanitarian resolve. Early operations transformed aircraft into lifelines, carrying children across borders and conflict zones under austere and often perilous conditions. In early humanitarian flights, the 1939 Czech Kindertransport was the first to demonstrate aviation's potential for child rescue. This was followed by postwar efforts such as Operation Magic Carpet and Cold War evacuations such as Operation Peter Pan. Infants and children were transported with limited medical support, relying on improvisation, speed, and human determination. Operations Babylift, Moses, Joshua, and Solomon increased the scale and ambition of these efforts, incorporating newborns into long-range missions under extraordinary logistical and political constraints. Though primitive by today's medical standards, these flights proved that aircraft could be used for more than war; they could also protect and save lives. Modern neonatal aeromedical transport realizes this vision with dedicated aircraft, incubators, and specialized teams capable of sustaining critically ill neonates across continents. Programs such as the Netherlands' helicopter emergency medical service, the European Air Ambulance, and the United Kingdom's Children's Air Ambulance continue the ethical and humanitarian legacy of these pioneering missions. When an infant's life is at risk, flight is imperative. Each neonatal air mission carries forward a century of courage, innovation, and moral conviction, turning the sky into a corridor of survival for the most vulnerable. Bellini C, Davis A, Stocking JC. From humanitarian airlifts to neonatal intensive care in the sky. Aerosp Med Hum Perform. 2026; 97(7):550-560.
Existing forest smoke detection models face limitations in recognizing small targets, achieving real-time performance, and maintaining high inference efficiency on edge devices. To overcome these challenges, this study proposes a novel lightweight multi-scale You Only Look Once (LM-YOLO) model that enhances detection accuracy and real-time capability while ensuring computational efficiency. The LM-YOLO integrates the backbone feature extraction and multi-scale fusion mechanisms of YOLOv12n. Specifically, we introduce the RFMBlock to enhance the fused representation of shallow and deep features, considering the visual characteristics of forest smoke. Meanwhile, the two-path downsampling module achieves efficient downsampling with minimal spatial information loss. To further improve localization accuracy for small and blurred smoke regions, we employ the Shape-IoU loss function. Extensive experiments on the public try123-v4 forest fire smoke dataset demonstrate that, compared with the baseline YOLOv12n under the same experimental conditions, LM-YOLO reduces the number of parameters by 34.5%, decreases the computational cost by 30.2%, and improves detection precision by 4.7%. In addition, the model achieves 92.7% precision on the public try7 dataset. These results outperform existing methods and highlight the strong adaptability of LM-YOLO for edge deployment, ultimately providing reliable technical support for early forest fire warning using unmanned aerial vehicles.
Curricular internships are affective-motivational learning contexts in which students encounter real workplace demands while educational institutions remain responsible for learning, engagement, and well-being. Responding to the Special Issue theme of emotion, motivation, and learning, this three-wave study used temporally separated self-report data to examine challenge demands, hindrance demands, and school support among 860 Taiwanese technical and vocational education and training (TVET) interns. Challenge demands were positively associated with work engagement, which was associated with innovative behavior. Hindrance demands were positively associated with burnout, which was associated with intention to seek work outside the trained vocational field. The hindrance demands-burnout association was weaker when school support was higher. The findings are compatible with treating school support as a curricular psychological resource that may help students interpret and manage obstructive internship conditions. More broadly, the study suggests that work-integrated learning systems may support vocational persistence by designing internships as supervised affective-motivational learning environments rather than as placements alone.
This work presents an experimental dataset for the detection of corona and complete breakdown discharges in air under sinusoidal alternating current (AC) supply and direct current (DC) supplies at different values of the pressure-distance product. The dataset comprises 1764 experiments performed in a low-pressure chamber using two types of electrodes, namely a rod-plane and a sphere-plane. The experiments were conducted under 7 different pressure conditions (from the atmospheric pressure to 1% of the atmospheric pressure), with the electrodes placed at 14 different heights with respect to the flat ground plane (from 100 mm to 0.5 mm). All these tests were done under sinusoidal 50 Hz AC supply, positive DC (+DC) and negative DC supply (-DC). Each experiment consists of three repetitions under the same experimental conditions. The dataset includes the corona inception voltage or the complete breakdown voltage at each experimental condition. This dataset can be useful for modelling and validating accurate predictive discharge models under different pressures and for designing physics-informed insulation systems for more electric and all-electric aircraft.
Artificial cloud seeding, as a direct intervention to enhance precipitation and an indirect method to reduce the ground particulate matter (PM) concentrations, has gained increasing attention in recent years for its potential applications in improving air quality. Our analysis of PM observations in the north of Yangtze River Delta (Xuzhou and Suqian) during 2022-2023 showed that PM wet removal efficiency increases linearly with rainfall intensity above threshold values, while the scavenging efficiency of gaseous pollutants showed no precipitation-dependent. In an aircraft seeding experiment in Suqian during the 2023 Shanghai Expo, AgI-induced ice nucleation triggered deposition growth of ice crystals, releasing latent heat that strengthened local updrafts and promoted subsequent riming and melting. Post-seeding observations (3-hour period) observed precipitation rates of 0.1-0.3 mm/h with PM10 and PM2.5 reductions of 25 %-29 % and 10 %-16 %, respectively, despite low wind speed indicating seeding-influenced precipitation improved PM scavenging. Model simulations combined with observational scavenging rates showed the domain-wide impacts over an area of ∼9000 km2 area and an enhanced rainfall of 90,000 tons. However, PM reductions were modest (<1 %) across the entire domain. Regions with strong updrafts (> 0.5 Pa/s) showed higher scavenging efficiencies with PM reductions of 1 % over 900 km2, 4 %-5 % over 100 km2, and > 10 % in localized areas (40 km2). These results highlight that targeted cloud seeding can improve the surface rainfall and PM wet deposition, with the effectiveness of the process driven by microphysical-dynamical feedbacks.
Saskatchewan relies extensively on air transport to deliver acute care to remote regions. This article applied Royal Canadian Air Force air power doctrine to evaluate and optimize the province's civilian medevac system. Doctrinal analysis was used to assess existing medevac coordination structures. Operational modeling, including an optimized combined air operations model, was developed to compare the efficiency of fixed- and rotary-wing transport across representative provincial locations. Data were analyzed for time to tertiary care. The application of air power principles, including centralized control, decentralized execution, and a common operating picture, identified significant opportunities to enhance responsiveness and increase efficiency. Modeling showed that the correct selection of transport modality improves efficiency by up to 42%, with fixed-wing aircraft favored beyond approximately 150 miles from Saskatoon. The analysis demonstrates that Saskatchewan's current air medical system could achieve improved safety, timeliness, and efficiency through a centralized command structure. Establishing a provincial medevac operations center would enable real-time tasking, integrated situational awareness through a common operating picture, and better alignment of air assets with clinical needs.
Current understanding of mental health problems among aviation pilots remains limited. Pilots are exposed to distinctive occupational stressors, and when psychological distress occurs, they may be reluctant to disclose symptoms or seek timely assistance because of concerns about stigma, loss of income, licensing restrictions, or medical disqualification from flying. Pilot mental health is therefore not only an occupational health issue, but also a critical component of aviation safety governance. Although the vast majority of mental health conditions do not lead to flight safety events, in rare circumstances, severe psychological crises that remain unidentified or unsupported may result in catastrophic outcomes, including aircraft-assisted pilot suicide. These tragic events underscore the potential safety implications of pilot mental health and highlight the urgent need for greater attention to this critical issue. This article argues that prevention should be centered on system-level measures, including confidential peer support, carefully governed digital tools, destigmatized safety cultures, and harmonized data infrastructures.