Search Results (1,483)

Submicron particulate matter in the 0.1–1.0 µm range is difficult to remove using conventional air pollution control devices because of its low capture efficiency. Condensation-induced particle enlargement has therefore been proposed as a preconditioning method to increase particle size before collection. This study aims to numerically investigate the condensation-induced growth of submicron particles in a cylindrical tube under different pressure-recovery conditions and to clarify how pressure-controlled supersaturation affects droplet-growth kinetics. A three-dimensional computational fluid dynamics (CFD) model was developed in ANSYS Fluent by coupling the Discrete Phase Model (DPM) with a custom User-Defined Function (UDF) growth law to predict droplet growth, condensation time, and associated heat and mass transfer characteristics. Initial particle diameters of 0.1–1.0 µm were examined for growth to a target diameter of 5 µm under initial pressure conditions of 0.5–0.9 bar followed by recovery to 1 atm, corresponding to calculated nominal supersaturated RH values of 202.65–112.58%, respectively. The results show that pressure-induced supersaturation is the dominant factor controlling condensation kinetics. Lower initial pressures resulted in shorter condensation times and higher mass and heat transfer rates. For an initial diameter of 0.5 µm, the condensation time decreased from approximately 0.1434 s at 0.9 bar to 0.0167 s at 0.5 bar, corresponding to an 88.35% reduction. These findings indicate that pressure-controlled supersaturation can significantly accelerate submicron particle enlargement and provide design guidance for condensation-assisted fine-particle removal technologies. Full article

Cervical cancer constitutes a major global health burden with a high incidence rate. Despite its well-established role in genome stability and cell cycle regulation, its specific anti-tumor mechanism involving the induction of a senescence-like state remains unclear. To determine whether Mg²⁺ impedes cervical cancer progression through the induction of a senescence-like phenotype via the ATM/CHK2/p21 pathway, HeLa cells were used in this study. Cell proliferation, migration, and invasion were measured using CCK-8, EdU, wound-healing, and Transwell assays, while SA-β-gal staining and western blotting served to examine both senescence-related markers and pathway protein expression. A BALB/c nude mouse xenograft model was established to evaluate tumor growth and safety following intratumoral Mg²⁺ injection. The results showed that Mg²⁺ inhibited proliferation, migration, and invasion in a concentration-dependent manner. Treatment with 20 mM Mg²⁺ increased SA-β-gal positivity, decreased Lamin B1 expression, and activated the ATM/CHK2/p21 pathway; moreover, this upregulation of p21 was reversed by an ATM inhibitor. ELISA revealed that 10 mM Mg²⁺ enhanced IL-6 and TNF-α secretion, confirming effective induction of the senescence-associated secretory phenotype, while higher concentrations diminished this effect, which may be partly attributed to the reduction in cell viability. In vivo experiments showed that Mg²⁺ inhibited tumor growth without notable alterations in body weight, liver and kidney function, or serum magnesium levels. In summary, the localized high concentration of magnesium ions induces cells to enter a senescence-like state via the ATM/CHK2/p21 pathway, thereby selectively suppressing malignant cellular behaviors. Notably, its in vivo efficacy and safety profile in vivo are favorable. It is also worth noting that these findings should be interpreted within the context of a preclinical, high-dose local Mg²⁺ model. Full article

Background/Objectives: Merkel cell polyomavirus (MCPyV) is a ubiquitous virus strictly associated with Merkel cell carcinoma (MCC), a rare and aggressive skin cancer. MCPyV oncogenic properties are associated mainly with early protein expression, integration, and LT truncation. MCPyV can also interact with DNA Damage Response (DDR) mechanisms, contributing to oncogenesis and tumor progression. In this work, we investigated the correlation between MCPyV and MCC and evaluated the mRNA expression profiles of DDR genes in virus-positive and -negative tumors. Methods: A total of 19 formalin-fixed paraffin-embedded biopsies were acquired from patients diagnosed with MCC. After DNA and RNA extraction, the DNA was used for MCPyV detection via qPCR and for sequencing analysis of the early, late, and non-coding control viral regions and the extracted RNA was used for MCPyV transcripts, miRNA detection and for the evaluation of several DDR genes expression such as ATM, ATR, CHK1, CHK2, H2AX, Rad51, p53, and p21, in MCPyV-positive and -negative samples via reverse transcription, PCR, and qPCR. Results: MCPyV presence was detected in 11/19 samples, all characterized by viral integration, LT truncation, and early region expression only. Furthermore, higher mRNA levels of DDR genes were observed in MCPyV-positive tumors compared with the negative ones. Conclusions: Our findings support the role of MCPyV in MCC formation and suggest its involvement in the transcriptional regulation of DDR genes, which may influence tumor progression. Understanding the molecular interplay between MCPyV and the DDR may guide future research into plausible novel diagnostic and therapeutic strategies for virus-induced tumors. Full article

Artificial Intelligence (AI) is emerging as a transformative enabler in aviation, with applications spanning Guidance, Navigation and Control (GNC), Air Traffic Management (ATM), and predictive maintenance. However, the adoption of AI in safety-critical domains remains constrained by the absence of established certification guidance. Traditional standards such as Aerospace Recommended Practice (ARP), ARP4754B, ARP4761A, DO-178C, and DO-254 assume deterministic behaviour and verifiable logic, whereas AI exhibits adaptive and non-deterministic characteristics. Regulatory initiatives, including the European Union Artificial Intelligence Act, the European Union Aviation Safety Agency (EASA) AI Roadmap 2.0, the Federal Aviation Administration (FAA) AI Safety Assurance Roadmap, and ISO/IEC Technical Report (TR) 5469:2024, signal progress but remain fragmented, exploratory, and often limited to low-level autonomous use cases. This study adopts a qualitative approach combining literature and standards analysis with expert interviews to identify gaps in post-deployment assurance, data governance, explainability, and accountability. A conceptual life cycle-oriented framework is proposed that embeds AI-specific assurance activities such as dataset validation, iterative verification, drift detection, and retraining oversight into established certification processes. The framework extends classical and emerging verification and validation models into operational service, linking machine learning constituents to system-level safety arguments and regulatory expectations to support the development of trustworthy and certifiable AI-enabled aviation systems. Full article

Increased flight volumes necessitate urgent reforms in Airspace Management (ASM) to mitigate risks of fatalities and near-misses. In order to enhance aviation system safety, the International Civil Aviation Organization (ICAO) mandates that state parties must conduct the Universal Safety Oversight Audit Program (USOAP) to continuously monitor civil aviation. This research aims to identify critical factors influencing Thailand’s ASM by employing experimental design and Structural Equation Modeling (SEM) to analyze influences and relationships among communication, surveillance, navigation, Air Traffic Management (ATM), and ASM. The methodology includes stimulation and a questionnaire-based survey conducted with aviation professionals and mapping out their answers to find the influences, relationships, and importance of the different factors. The results were validated using various statistical tools. The findings indicate signi1ficant direct and indirect effects on ASM, emphasizing that effective communication and robust surveillance are essential for safety and operational efficiency. This study highlights the need to increase the ASM framework, providing actionable insights for optimizing air traffic control in response to the growing air traffic demand. Furthermore, SEM for Airspace optimization can be applied internationally to significantly reduce accidents and incidents in the future. Full article

The use of proton beam therapy (PBT), as a more precision-targeted radiotherapy technique, is increasing in the treatment of head and neck squamous cell carcinoma (HNSCC). PBT benefits from the precise delivery of the radiation dose to the tumour via the Bragg peak. However, challenges still remain in the treatment of HNSCC with radiotherapy, particularly with tumour radioresistance and recurrence, requiring strategies leading to radiosensitisation. There are added complexities with the use of PBT given the increase in linear energy transfer (LET) at and around the Bragg peak, which can cause an altered cellular response compared to low-LET radiation. Nevertheless, targeting the cellular DNA damage response is considered an important strategy to enhance tumour cell killing caused by radiotherapy. Therefore, using specific inhibitors against the protein kinases ataxia telangiectasia mutated (ATM), ataxia telangiectasia and Rad3-related (ATR) and the DNA-dependent protein kinase catalytic subunit (DNA-Pkcs), we investigated their impact in radiosensitising HPV-negative HNSCC cells to PBT of increasing LET. We demonstrate that inhibitors against ATR (AZD6738), and particularly ATM (AZD1390) and DNA-Pkcs (AZD7648), could significantly decrease clonogenic survival of HNSCC cell lines following PBT at both low and relatively high LET (~2 keV/µm and ~8 keV/µm, respectively). We confirmed that the inhibitors in combination with PBT led to DSB persistence through neutral comet assays and monitoring γH2AX/53BP1 foci. We also show that this strategy can enhance the sensitivity of patient-derived organoids of HNSCC to PBT of both low and high LET, highlighting this as a strategy which should be exploited further. Full article

Dynamic scene reconstruction from thermal infrared imagery remains insufficiently studied due to several inherent challenges, including low texture, low contrast, and radiometric ambiguity. In this paper, we present Thermal4D, a novel framework for reconstructing high-fidelity dynamic 3D scenes using only thermal images, without requiring visible-light inputs or auxiliary sensors. Built upon the 3D Gaussian Splatting paradigm, the proposed method introduces two key components. First, a frequency-aware attention module, termed TherHiLo, is designed to disentangle structural features across different frequency bands. Second, a physics-inspired atmospheric transmission module (ATM) is developed to model radiometric distortions caused by thermal imaging conditions. Although the reconstruction pipeline takes 8-bit thermal video sequences as input, high-precision 14-bit thermal frames are further exploited in TherHiLo to enhance attention learning with richer radiometric information. In addition, feature-level supervision from pretrained DINOv2 models is incorporated to improve structural consistency. To facilitate systematic evaluation, we also construct MVTD, a new multi-view dynamic thermal dataset. Experimental results on the MVTD and TI-NSD benchmarks show that Thermal4D consistently outperforms existing methods in both dynamic and static scenes, providing an effective framework for physics-consistent dynamic thermal scene reconstruction. Full article

Hydrogen storage remains a key challenge in the transition toward sustainable energy systems, particularly for applications requiring high energy density and safe operation. Among various solid-state storage materials, magnesium hydride (MgH₂) is considered highly promising due to its high hydrogen capacity, low cost, and good reversibility; however, its practical application is hindered by slow kinetics and high thermodynamic stability. In this study, Mg and Ni coatings were deposited on Al₂O₃ based substrates using a direct current plasma spraying technique to develop a composite system for enhanced hydrogen storage performance. The influence of plasma torch parameters on coating characteristics was investigated, and the hydrogenation behavior was analyzed under controlled conditions (350 °C & 200 °C, 5 atm H₂). The structural, morphological, and compositional evolution of the coatings before and after hydrogenation was examined using SEM, EDS, XRD, and FTIR techniques. Results demonstrate that plasma-sprayed Mg coatings undergo significant morphological transformation after hydrogenation, including surface cracking, increased porosity, and phase conversion to MgH₂, confirming effective hydrogen uptake. In contrast, Ni coatings exhibit limited hydride formation but play a catalytic role by facilitating hydrogen dissociation and improving surface reactions. The influence of plasma power on coating quality and hydrogenation efficiency was also identified, with higher power leading to improved coating uniformity and enhanced MgH₂ formation. Additionally, a reaction–diffusion model was developed to evaluate the effect of temperature and hydrogen pressure on hydride layer growth. The model predicts an optimal temperature range (~300–330 °C) for MgH₂ formation, beyond which thermodynamic instability limits hydride stability. Overall, the study demonstrates that plasma-sprayed Mg/Ni coatings on granular substrates represent a promising approach for developing efficient hydrogen storage systems, combining improved kinetics, structural stability, and scalable processing. Full article

One of today’s major challenges in air transport is accommodating future growth in traffic demand, which requires addressing capacity limitations. Since separation minima influence airspace capacity, technological progress enables exploring innovative approaches. This paper presents the Ad Hoc Separation concept, which involves applying different separation minima between aircraft pairs based on aircraft type, weight, encounter geometry, flight level, or wind. As a novel approach requiring operational changes to the current ATM system, further research is justified only if tangible benefits are demonstrated. Fast-time simulations in European en-route sectors, both conventional and Free Route Airspace, are performed to assess the benefits. The results show a capacity gain of about one aircraft per hour, along with positive environmental and cost-efficiency benefits. Full article

This study evaluates mission-long inter-sensor radiometric calibration biases in Sensor Data Record (SDR) and/or Temperature Data Record (TDR) radiances from NOAA microwave sounders, including Advanced Technology Microwave Sounder (ATMS) (Suomi National Polar-orbiting Partnership or SNPP, NOAA-20, NOAA-21) and Advanced Microwave Sounding Unit-A (AMSU-A) (NOAA-19). Using four complementary validation techniques within the Inter-Sensor Radiometric Bias Assessment (iSensor-RCBA) system—32-day averaging, Community Radiative Transfer Model (CRTM) Double Difference (DD), Simultaneously Nadir Overpass (SNO), and sensor-DD via SNO—we characterize long-term performance. Results indicate that the SDR/TDR radiance quality remains stable and generally meets scientific requirements throughout their operational lifetimes with minimal anomalies; observed anomalies were infrequent and primarily correlated with calibration-table updates or spacecraft events or instrument degradation. Moreover, this research examines how radiometric calibration biases for the three ATMS instruments vary with Earth scene radiance or temperatures using the CRTM and SNO methods, as well as the radiance-dependency of inter-sensor calibration biases across the three instruments. Notably, due to its exceptional stability over 14 years, despite an approximate two-month data gap, the SNPP ATMS TDR and SDR datasets are recommended as the ideal reference to link legacy AMSU-A and Microwave Humidity Sounder (MHS) with Joint Polar Satellite System (JPSS), QuickSounder, and MetOp-Second Generation (MetOp-SG) microwave instruments. Beyond quantifying data quality, our multi-method framework with iSensor-RCBA effectively diagnosed critical issues, including a simulation error for CRTM ATMS radiance related to the CRTM spectral-response approximation and a NOAA-19 AMSU-A channel-8 performance anomaly. These findings confirm the long-term integrity of NOAA microwave sounder records and reinforce the value of integrated cross-sensor calibration assessments. Full article

This in vitro study evaluated the effect of exposure duration (5, 20, and 40 days) to constant increased ambient pressure (2.4 atmospheres absolute; ATA) on microleakage at the dentin–composite interface of teeth restored with two bulk-fill composites. Specimens stored in distilled water at atmospheric pressure (1 atm) served as controls. A total of 192 extracted human molars with standardized Class V cavities were randomly assigned to two groups: sonic-activated bulk-fill composite (SonicFill) or conventional bulk-fill composite (Filtek One Bulk Fill). Each group was subdivided into controls maintained under atmospheric pressure (1 atm) and specimens under hyperbaric pressure (2.4 ATA), and exposed for 5, 20, or 40 days (total of 12 groups, n = 16 per group). Microleakage was assessed using the dye penetration method and scored under a stereomicroscope according to ISO criteria. Statistical analyses were performed using Fisher’s Exact chi-squared and Fisher–Freeman–Halton Exact tests (α = 0.05). No significant differences were found between materials or pressure conditions at 5 and 20 days (p > 0.05). After 40 days, both composites showed significantly higher microleakage at increased pressure than atmospheric controls (p < 0.05). Microleakage increased over time in the hyperbaric groups, while no time-dependent changes occurred at atmospheric pressure. After 40 days, prolonged exposure to elevated pressure increased microleakage, whereas shorter exposure produced no significant changes. Both materials demonstrated similar susceptibility to pressure-related deterioration. Full article

Background: Acute transverse myelitis (ATM) is an inflammatory disorder of the spinal cord with heterogeneous etiologies, including autoimmune, infectious, paraneoplastic, and drug-induced causes. Tumor necrosis factor-alpha (TNF-α) inhibitors have been infrequently associated with inflammatory central nervous system events, including transverse myelitis. TNF-inhibitor-associated myelitis typically presents with short-segment lesions, a normal brain MRI, and partial responsiveness to corticosteroids. Longitudinally extensive transverse myelitis (LETM) and steroid-refractory cases are uncommon. Case Presentation: A 39-year-old woman with psoriatic arthritis treated with etanercept for two years presented with subacute progressive bilateral lower-extremity sensory loss and weakness. MRI revealed a T2 hyperintense spinal cord lesion extending from T11 to L1 with gadolinium enhancement, consistent with transverse myelitis, while brain MRI was normal. Cerebrospinal fluid analysis showed lymphocytic pleocytosis, elevated protein, oligoclonal bands, and increased kappa free light chains. Extensive infectious, metabolic, paraneoplastic, and autoimmune testing, including aquaporin-4 and MOG antibodies, was negative. Despite high-dose intravenous corticosteroids and the discontinuation of etanercept, the patient experienced clinical worsening with lesion expansion, meeting criteria for LETM, and developed urinary retention. She subsequently underwent plasma exchange, resulting in radiologic improvement and moderate clinical recovery. Conclusions: This case highlights an atypical presentation of TNF-inhibitor-associated myelitis characterized by a biphasic course, longitudinally extensive spinal cord involvement, steroid refractoriness, and responsiveness to plasma exchange. These features suggest either an unusually severe TNF-inhibitor-related inflammatory phenotype or a TNF-inhibitor-triggered antibody-mediated demyelinating process. Reports of TNF-inhibitor-associated myelitis evolving into longitudinally extensive, steroid-refractory disease remain limited, and this presentation may broaden the recognized clinical spectrum of TNF-α-related CNS inflammatory events. Close neurologic follow-up and heightened awareness of severe CNS complications associated with TNF-α inhibitors are warranted. Full article

This paper presents the results of numerical calculation of steady-state magnetorheological fluid flow in the gap of an eccentric seal subjected to an external radial magnetic field. A coupled problem combining magnetic field analysis and laminar viscoplastic flow with Bingham rheology is solved to obtain pressure and velocity distributions within the seal gap, from which the hydrodynamic reaction forces of the fluid film and the rotor friction torque are determined. A parametric study was conducted in the ranges of rotor angular velocity ω = 100–400 rad/s, relative eccentricity ε = 0–0.9, and magnetic flux density B₀ = 0–0.5 T at the pressure differential Δp = 2 atm. Analysis of the results shows that increasing the magnetic flux density from 0 to 0.5 T leads to an increase in the seal reaction force from 12 N to 642 N and the friction torque from 0.35 N·m to 11.23 N·m. The most intensive growth of both characteristics is observed in the range B₀ = 0–0.3 T, beyond which saturation occurs as the MRF yield stress reaches its plateau value. An optimal control range of B₀ = 0.1–0.2 T was determined, ensuring maximum seal energetic efficiency as quantified by the load capacity-to-friction torque ratio, which is maximized at 70 N/(N·m). Based on the obtained results, the consequences of using magnetorheological seals on the performance of the rotor system are discussed, including the analysis of the sealing effect on rotor-dynamic stability. Within the proposed optimal range, it is shown that an increase in magnetic flux density leads to a sign reversal of the horizontal reaction F₂, while the monotonic growth of the ratio |F₂|/F₁ indicates an intensification of cross-coupling and a corresponding reduction in the rotordynamic stability margin at higher values of B₀. Full article

European airspace is currently facing significant challenges due to increasing traffic demand and limited sector capacity. This situation leads to an overload of demand, so Air Traffic Controllers (hereinafter ATCOs) are often forced to implement regulations that cause delays. Moreover, an ATCO cannot be endorsed in an unlimited number of sectors, as doing so would compromise the maintenance of operational proficiency and specific sector skills. Consequently, the limited cross-sector flexibility of controllers has become a key constraint in optimizing airspace management. Additionally, the strategic definition of sector groups has a direct impact on which sector configurations can be activated. An inadequate sector grouping strategy may hinder operations by restricting access to more efficient sector configurations. While in some cases, controllers may be endorsed for multiple sectors (up to ten), this flexibility remains insufficient to mitigate capacity and efficiency challenges fully. IFAV3 (Increased Flexibility of ATCO Validation En-Route) project has been developed within the Single European Sky ATM Research (hereinafter SESAR) framework, aiming to maximize flexibility in ATCO rostering. Its main expected benefits include an improvement in cost efficiency in Air Traffic Control (hereinafter ATC) through reduced training costs and optimized rostering by a better utilization of existing capacity. Full article

Monitoring dissolved carbon dioxide (CO₂) in aquatic and sediment systems is critical for understanding carbon cycling and climate feedback. This study develops and characterizes a compact, low-cost microbolometer-based attenuated total reflectance (ATR) mid-infrared sensor for direct dissolved CO₂ measurement in liquid and soil-water environments. The system integrates a ZnSe ATR crystal with custom suspended SiN membrane microbolometers and uses evanescent-wave absorption at 4.26 μm with a broadband LED source and computational spectral reconstruction, eliminating the need for an interferometer. Calibration shows excellent linearity (R² ≈ 0.99) over 50–1000 ppm CO₂, with a practical limit of detection (LOD) of ~26–35 ppm at 5–25 °C. UV-induced CO₂ generation from soil-water mixtures was investigated across UV wavelengths, revealing UV-C (254 nm) as optimal, producing net ΔCO₂ ≈ 339 ppm above ambient levels in 30 min. Environmental factors (temperature 5–35 °C, pH 5–11, pressure 1–1.5 ATM, dissolved organic carbon) were systematically evaluated, confirming robust sensor performance (accuracy >90%, correlation r > 0.98 with reference instrument). This sensor represents the first integration of MEMS microbolometer detectors with ATR evanescent-wave spectroscopy for liquid-phase dissolved CO₂, enabling real-time monitoring and rapid sediment organic carbon assessment in a field-deployable platform. Full article