Search Results (2,243)

Fetal cardiac ultrasound screening is vital for the prenatal diagnosis of congenital heart disease (CHD). However, understanding complex cardiovascular structures and continuity from two-dimensional (2D) ultrasound images remains challenging. Therefore, this study developed and evaluated an artificial intelligence (AI)-based three-dimensional (3D) visualization approach that reconstructs fetal cardiovascular structures from 2D ultrasound sweep video. To this end, information from the adjacent frames was used. Instead of interpreting each ultrasound frame independently, this method incorporates neighboring frames, enabling the continuous visualization of the right- and left-sided functional circulatory pathways. Our method achieved a mean Dice coefficient of 0.785 on an independent test dataset, demonstrating that the adjacent frame information can provide stable 3D segmentation. Diffusion-based anatomical plausibility analysis trained exclusively on normal anatomies showed exploratory discrimination between normal fetuses and fetuses with CHD (AUC, 0.861; 95% CI, 0.695–0.980). In a clinical comparison study involving 12 obstetricians, the introduction of this AI-driven 3D cardiovascular visualization slightly improved the screening accuracy from 0.779 to 0.808 and significantly improved the confidence-weighted accuracy score (p = 0.002). Our approach can potentially support examiners and facilitate fetal cardiac ultrasound screenings. Full article

The semiconductor industry faces converging pressures from energy-constrained edge electronics and energy-bottlenecked high-performance computing, motivating heterogeneous monolithic three-dimensional (M3D) integration as a system-level response. M3D imposes a strict back-end-of-line (BEOL) thermal budget on upper-tier devices, restricting the channel materials and contact processes available and degrading conventional thin-film transistor performance. The source-gated transistor (SGT), in which drain saturation is set by gate-modulated injection across an engineered source barrier rather than by drain-side channel pinch-off, provides a device-level response: low saturation voltage, high output impedance, large intrinsic gain, and tolerance to channel-length variation, all achieved with moderate-mobility and nonideal-contact channel materials. This review organizes reported SGTs by source-barrier architecture and channel-material platform, develops a spatial characterization framework that complements electrical measurements for unambiguous identification of source-controlled operation, and surveys applications across standalone edge electronics and BEOL-compatible upper tiers in M3D stacks. Integrating non-volatile memory mechanisms into the source barrier further extends SGTs into a compute-in-memory and neuromorphic upper-tier role in which the voltage-invariant saturation current itself functions as a programmable, read-bias-robust state variable. Together, these considerations position SGTs as a flexible architectural primitive for heterogeneous M3D platforms that address the energy demands of both edge and high-performance computing. Full article

To identify severe missing events in low-voltage distribution network (LVDN) measurements under coexisting errors and asynchrony, a label-free severe missing event detection method based on the mean shift test is proposed. First, mathematical models for the error rate, asynchrony rate, and missing rate are established to describe typical gray measurement data scenarios in LVDNs, where errors and asynchrony are treated as background disturbances. Second, a phase-specific current regression model for severe missing-event detection is constructed based on the multiple linear relationship between the phase-line head-end current and the customer-side currents. Then, the mean shift test is introduced to detect abnormal time snapshots caused by severe missing events through statistical hypothesis testing. Simulation results show that the proposed method achieves a high TPR while maintaining a low FPR in the main comparative experiments, and it achieves the best overall TPR–FPR trade-off among the evaluated methods. The results demonstrate that the proposed method provides an effective means for label-free detection of severe missing events in LVDNs under background measurement disturbances and the operating conditions considered in this study. Full article

The Internet of Vehicles (IoV) relies on frequent vehicle-to-roadside-unit (RSU) access over open wireless channels, making efficient authentication and key establishment essential. In many existing authentication and key agreement (AKA) schemes, a target RSU receives and processes a request before an invalid sender is rejected, which can waste roadside computation under dense invalid-request traffic. This paper presents EDAKA-IoV, an elliptic-curve-cryptography-based AKA scheme that separates admission filtering from end-to-end session-key establishment. A trusted authority (TA) performs Lightweight Polynomial-based Pre-Verification (LPPV) to discard invalid authentication requests before they reach the target RSU, while the vehicle and RSU establish the final session key. A current–pending dual-state mechanism prevents permanent de-synchronization during dynamic pseudo-identity renewal without adding another communication round. Formal analysis under an eCK-style model, ProVerif verification, and heuristic analysis evaluate session-key secrecy, injective mutual authentication, privacy, and resistance to the considered attacks. Optional offline precomputation moves two fixed-base scalar multiplications outside the online phase and reduces the non-polynomial online computation component by approximately 48.8%. With fixed-length compressed point encoding, the authentication exchange requires 2336 bits. The workload analysis shows that the RSU-side processing reduction is proportional to the invalid-request ratio, while the TA still performs record lookup, hashing, and degree-dependent polynomial evaluation for every received request. EDAKA-IoV therefore provides a balanced authentication solution for resource-sensitive IoV deployments. Full article

Heart failure (HF) is a systemic syndrome in which prognosis depends on cardiac dysfunction, congestion, cardiorenal and cardiohepatic interactions, inflammation, and metabolic dysregulation. The liver is exposed to elevated systemic venous pressure and reduced forward flow, and contributes to albumin and coagulation factor synthesis, bile acid metabolism, iron homeostasis, and the acute-phase response. Cardiohepatic injury involves hemodynamic stress, sinusoidal endothelial dysfunction, oxidative stress, inflammatory signaling, fibrogenesis, and altered metabolic regulation. Congestive hepatopathy is associated with right-sided HF, tricuspid regurgitation (TR), pulmonary hypertension, and elevated central venous pressure, whereas hypoxic hepatitis develops during low-output states, shock, or acute circulatory deterioration. These mechanisms may coexist, producing congestive/cholestatic, hypoperfusive/ischemic and mixed/systemic reserve profiles. Composite liver-related scores, including Model for End-Stage Liver Disease (MELD), MELD excluding International Normalized Ratio (MELD-XI), MELD with sodium (MELD-Na), MELD-Albumin and albumin–bilirubin (ALBI) score, may reflect congestion, hepatorenal dysfunction, nutritional status and reduced systemic reserve. This review summarizes hemodynamic and molecular mechanisms of cardiohepatic injury, liver-related biomarkers and composite scores, with emphases on advanced HF, left ventricular assist device (LVAD) therapy and heart transplantation. Liver-related abnormalities remain underrecognized in HF. Their serial interpretation may support risk stratification, but composite scores should complement rather than replace comprehensive clinical assessment. Full article

Repeated mining of shallow-buried close-distance coal seams can disturb the fractured strata remaining in the goaf of the upper coal seam. Under gully terrain, mining disturbance is coupled with surface-relief effects, which may reactivate the overburden structure and induce dynamic strata-pressure behavior. In particular, when the working face advances across gullies, the change in surface slope alters the spatial distribution of roof load, while lower-seam extraction further disturbs the fractured rock mass formed by upper-seam mining, increasing the risk of severe strata-pressure behavior and support-crushing accidents. Taking the cross-ditch mining of the 2⁻² and 3⁻¹ coal seams in Anshan Coal Mine as the research object, this study integrates field geological investigation, theoretical calculation, physical similarity simulation, and field engineering verification to analyze overburden structural evolution, key-stratum breaking characteristics, and support-load variation under gully terrain. The results show that gully landforms generate obvious nonuniform loading above the working face. During upslope advance, the roof load gradually increases from the goaf side to the solid-coal side, causing tensile stress concentration at the fixed end of the key stratum and accelerating rock-stratum failure. A cantilever rock-beam mechanical model subjected to parabolic nonuniform loading was established, and the maximum breaking interval of the key stratum was calculated as 24.09 m. With increasing gully slope angle, the load gradient intensifies, the rock-beam breaking interval decreases, and the risk of overburden instability increases. Physical similarity simulation indicates that, when the 2⁻² coal seam working face passes through the 45° steep-slope section, the fractured overburden is more likely to form a stepped rock-beam structure, accompanied by slope rotation, stepped surface subsidence, and a sharp increase in support pressure. Under the 30° gentle-slope condition, The lateral confinement effect is stronger, roof movement is more gradual, and support-pressure fluctuation is reduced. During subsequent extraction of the lower 3⁻¹ coal seam, repeated mining disturbance reactivates the overlying goaf structure, and the upper stepped rock beam and lower hinged rock beam couple to form a double composite structure. When the fracture lines of the upper and lower key strata are staggered, the instability load of the upper structure is mainly buffered by caved gangue and interburden strata. The calculated support resistance in the asynchronous breaking stage is 8248.04 kN, which agrees well with the field-measured value of 8273 kN. When the fracture lines tend to coincide and synchronous breaking occurs, the unstable load of the upper key block is transferred downward and superimposed on the structural load of the lower key block, increasing the required support resistance to 15,165.55 kN, far exceeding the rated working resistance of the ZY9200/15/29 hydraulic support. Sensitivity analysis indicates that gully slope angle is the dominant factor affecting support resistance. As the slope angle increases from 30° to 60°, the support resistance increases from 13,228.65 kN to 18,278.43 kN, and the normalized support-resistance index increases from 0.872 to 1.205. Therefore, synchronous breaking of double key strata is the main mechanical cause of sudden support-load increase and support-crushing risk during cross-ditch mining of shallow-buried close-distance coal seams. The results can provide a basis for hydraulic support selection, roof weakening, weighting-interval control, and dynamic strata-pressure prevention under similar conditions. Full article

Background: Pakistan is one of only two countries where wild poliovirus type 1 (WPV1) continues to persist. Vaccine refusals challenge efforts to end the virus, especially in high-risk communities. Methods: A qualitative exploratory study took place from September to November 2025 in three High-Risk Union Councils (HRUCs) of Karachi, Pakistan. The study examined reasons for refusing the polio vaccine and identified specific communication and operational strategies to improve vaccine acceptance. A total of 23 in-depth interviews and 10 focus group discussions were conducted with 71 participants, including parents who refuse the vaccine, polio program staff, physicians, and government stakeholders. Data were analyzed using a sequential inductive and deductive thematic approach, mapping findings onto the Socio-Ecological Model (SEM) with NVivo 15 (Lumivero, Denver, CO, USA). Results: Factors influencing polio vaccine refusals were interconnected and spanned multiple levels. At the intrapersonal level, campaign fatigue, a lack of knowledge about poliomyelitis, concerns about side effects, and rumors about infertility were common. Community-level factors included household gatekeepers, local influencers, and digital misinformation. Institutional barriers included weak communication from the frontline, inadequate supervision, workforce shortages, poor tracking of refusals, and limited involvement of physicians. At the policy level, refusals were linked to distrust in governance, poor municipal services, and dissatisfaction with vertical campaign methods. Recommended strategies included integrating polio services with routine immunization and primary healthcare, strengthening counseling by physicians, engaging trusted local influencers and community leaders, expanding targeted social media campaigns to counter misinformation, implementing quick responses to rumors, enhancing workforce capacity, and using data-driven microplanning, including targeted SNIDs and focused interventions in areas with chronic refusals. Conclusions: Polio vaccine refusals are shaped by social, communication, operational, and structural factors. Improving communication and operational guidelines by reducing the number of campaigns, increasing active engagement at the frontline, integrating polio activities into routine health services, and addressing misinformation with a dynamic communication strategy may enhance vaccine acceptance and support polio eradication efforts. Full article

Background: The right renal vein is about half the length of the right renal artery and is shortened further by endovascular stapling at laparoscopic donor nephrectomy. Right-sided living-donor grafts carry roughly twice the adjusted risk of delayed graft function and of early graft loss, a penalty absent from deceased donation, where the inferior vena cava accompanies the graft. The deficit is one of venous length, not of the organ; extension is the remedy, and no guideline specifies how the conduit should be obtained. Methods and cases: Three consecutive recipients of right living-donor kidneys had the renal vein extended with a deceased-donor iliac vein. Conduits were recovered at multiorgan retrieval from ABO-identical or ABO-compatible donors, immersed in University of Wisconsin solution at 4 °C, and used within seven days; elective right donor nephrectomy was booked to follow a suitable retrieval within that window. Extension was an end-to-end back-table anastomosis with continuous 5-0 or 6-0 polypropylene, converting a short-vein implantation into a routine end-to-side anastomosis to the external iliac vein. All three grafts functioned immediately, without venous thrombosis, technical graft loss, or delayed graft function; the last serum creatinine was 0.91, 1.22, and 1.42 mg/dL. Conclusions. A calibre- and ABO-matched deceased-donor iliac vein, held in University of Wisconsin solution at 4 °C and used within seven days, makes venous extension a scheduled step of an elective right living-donor operation and requires no cryopreservation infrastructure. Where a donor’s safety mandates right nephrectomy, a short right renal vein need not preclude donation. Three cases establish feasibility; the low thrombotic risk of venous extension rests on published series rather than on this report. Full article

Non-uniform discharge temperature during sinter cooling is a practical issue in ironmaking, as local overheating may increase the thermal load on downstream conveying equipment. To mitigate insufficient cooling in the upper sinter bed under the conventional bottom-blowing mode, this study developed a three-dimensional transient CFD model for an industrial continuous annular cooler and optimized the air-supply strategy in Zones IV and V. Under the conventional condition, ambient air is supplied independently to Zones IV and V from the bottom wind boxes. In the novel air-supply strategy, while keeping the total fresh cooling-air flow rate in the final cooling region unchanged, ambient air is introduced from the upper side of Zone V and discharged from its bottom; the outlet gas from Zone V is then supplied to the bottom of Zone IV, forming a serial air-supply path. The results show that the novel arrangement improves the spatial matching between the cooling gas and the sinter bed during final cooling and suppresses the local high-temperature region near the discharge end. The maximum discharge temperature decreases from 459 K to 410 K, below the process limit of 423 K, while the average discharge temperature decreases from 377 K to 364 K. Based on the enthalpy-flow difference calculation, the predicted recoverable waste heat also increases under the novel condition. These findings suggest that redesigning the gas-flow route in the final cooling region can effectively enhance the uniformity of the discharge temperature in industrial annular coolers. Full article

In response to the significant seasonal fluctuations in heating and cooling loads in greenhouses for high-value fruit trees in northern China, as well as issues such as heat accumulation on the ground-source side and high carbon emissions from coal-fired heating, this paper proposes a coupled energy supply system comprising a PVT system, a mine pit seasonal thermal storage unit, a ground-source heat pump and a cooling tower. Taking a 30,000 m² cherry greenhouse and an existing 15,000 m³ mine pit thermal storage reservoir in Weifang, Shandong Province, as the research objects, annual design-stage simulations with a 0.125 h time step were conducted using SketchUp-TRNBuild and TRNSYS. Discrete sensitivity analyses and engineering constraints were used to determine the PVT area and cooling tower outlet temperature. Heating demand mainly occurred from November to February, whereas cooling demand was concentrated from June to September. The selected 2452 m² PVT system supplied direct heating for 34 days, covered 23.05% of the seasonal heating demand, and achieved a storage efficiency of 69.17%. Without a cooling tower, the first-year soil temperature increased by 1.1 °C. With a 26 °C cooling tower outlet temperature, the soil thermal imbalance ratio decreased to 2.4%, and the 15-year soil temperature rise was limited to 0.28 °C. The recommended system required 1.3239 million kWh of net purchased electricity annually, reduced operating costs by approximately CNY 802,800 (USD 118,243) and operational emissions by 2027.8 tCO₂-eq per year relative to the baseline, and had a static payback period of 6.4 years. The annual operational emission reduction was linearly extrapolated over a 20-year assessment period under fixed weather, load, equipment performance, and grid emission assumptions, resulting in a scenario-based carbon reduction threshold of 40,556 tCO₂-eq. Net life cycle carbon savings would be possible if the additional emissions from construction, equipment replacement, and end-of-life treatment remained below this threshold. Full article

To address the challenge of surrounding rock control in deep gob-side entry driving, the return airway of the 20203 working face of the Dahaize Coal Mine was taken as the engineering background. The stress, deformation and plastic zone evolution characteristics of the surrounding rock of the gob-side entry were studied through theoretical analysis, numerical simulation and field tests, and the surrounding rock control mechanism and the double-layer flexible thick anchor control technology were proposed. The results show that under the influence of the adjacent gob, the peak compressive stress of the gob-side entry is transferred to the solid coal side, and tensile stress areas are generated on the roof; shear failure is the main failure pattern of the surrounding rock in the gob-side entry, which is characterized by significantly asymmetric deformation. Based on the displacement failure characteristics of the surrounding rock zones, a double-layer flexible thick anchorage structure was constructed. The anchorage depth of the first basic support exceeds the critical thickness of the shallow fractured surrounding rock zone, forming a thick load-bearing layer for the roadway surrounding rock; the anchorage depth of the secondary reinforced support extends into the stable rock mass, enhancing the bearing capacity of the anchored body and the roadway surrounding rock. The results of numerical simulation show that after adopting a double-layer flexible thick anchor support, the average deformation of the roof decreases by 48.81%, and the range of the tensile stress zone and plastic zone is significantly reduced. In engineering applications, the average deformation of the roadway roof was 42.58 mm, the two-end convergence was 0–2 mm, the roof separation value was controlled within 0–30 mm, and the rock strata within 0–5.0 m remained intact. This technology effectively suppresses the large deformation of the surrounding rock in deep gob-side entry, providing an innovative strategy for roadway stability control under comparable geological and mining conditions. Full article

As generative AI chatbots become a primary information channel, users increasingly accept answers without verification, and citations can raise trust even when sources are irrelevant or fabricated. How source-attribution visualization shapes the visual preconditions of verification remains unknown: users can notice, read, or compare a source without clicking. This within-subjects eye-tracking study (N = 23; 92 trials) evaluated four attribution visualizations abstracted from commercial AI chatbots and rendered as simulated screens: inline component (sentence-end chips), card list (cards above the answer), side panel (adjacent panel), and raw hyperlink (bare URLs), combining gaze metrics, surveys, and interviews. Repeated-measures ANOVAs revealed strong layout effects on source discoverability and engagement, largely robust to sensitivity checks (the panel’s discovery latency was order-sensitive): the card list was discovered almost immediately, with the raw hyperlink last. Yet no self-reported measure differed detectably. The most frequently nominated format, the inline component, attracted about half the dwell time of the stand-alone formats, whose prolonged fixations suggested citation-to-text mapping cost rather than genuine engagement. This attention–preference gap means both must be measured jointly. We contribute a four-layout gaze-based comparison, a reproducible participant-level analysis workflow, and three design principles (pre-click identifiability, sentence-level claim–source mapping, and in situ preview) within a proposed two-stage attribution architecture. Full article

The growing research interest in diode rectifier unit-based modular multilevel converter (DRU-MMC) configurations has made it imperative to analyze their potential impact on the short-circuit current characteristics of future AC grids. Most existing short-circuit current calculation approaches are oriented toward DC-side fault scenarios, while systematic research on AC-side fault analysis remains incomplete. To address this limitation, this work first illustrates the operating mechanism of the MMC. The short-circuit current at the fault point is decomposed into two independent components based on the superposition theorem. These components are: the current injected by the MMC and the current originating from the AC system. This work further explores the regulatory mechanism by which dq-axis limiting and fault-ride-through current limiting shape the MMC’s output current and derives an analytical equation for its amplitude. Furthermore, the phase correlation between the MMC-injected current and the AC system current under symmetrical fault conditions is clarified, and the computational formula for the aggregate short-circuit current is established. Then, considering the influence of transition resistance, the proposed method is verified to be applicable to both symmetrical metallic and non-metallic faults. Then, the symmetrical component method is used to analyze the sequence component of asymmetric fault short-circuit current, and a negative-sequence suppression (NSS) strategy is introduced. At the same time, considering the influence of transition resistance, the calculation formula of asymmetric metal and non-metal fault short-circuit current is derived. At the final stage of the study, a two-terminal simulation model is constructed in the PSCAD/EMTDC simulation environment. Comparative verification confirms that the results derived from theoretical calculation are in strong agreement with the simulation outcomes. The approach introduced here offers a favorable combination of simplicity and precision, rendering it highly suitable for practical engineering use. It reliably determines the short-circuit current under various fault conditions, thereby supporting fault-current analysis and the coordination of protective relays on the AC side of the receiving-end MMC in a DRU-MMC system. Full article

With the rapid development of recycling and secondary utilization of end-of-life battery materials, it is crucial to clarify the impact of full-lifecycle degradation on the thermal safety limits of lithium-ion batteries. This study focuses on a 16 Ah NCM613|graphite pouch battery. First, it analyzes the evolution of capacity decay, thickness expansion, and internal resistance during cycling at room temperature (25 °C) and high temperature (45 °C). Furthermore, an adiabatic accelerated calorimeter (ARC) is employed to investigate the influence of different states of health (SOH) levels (95% and 85%) on the battery’s thermal runaway characteristics. The findings indicate that, macroscopically, batteries in all states follow similar voltage–temperature failure pathways, with mass loss rates confined to a narrow range of approximately 16%, emphasizing the low catastrophic potential of mid-nickel chemistry. However, the microscopic kinetic mechanisms exhibit significant anisotropy: although thickness and internal resistance display no apparent abrupt increase during the late stage of room temperature aging, the capacity exhibits a highly nonlinear plunge behavior. The severe internal lithium plating side reaction triggered by this phenomenon causes the self-heating onset temperature to drop rapidly from 130.0 °C in the fresh state to 79.7 °C. Concurrently, the activation energy of the exothermic side reaction, fitted using a simplified Arrhenius equation, exhibits a non-monotonic variation with aging progress. In the early stages of aging at 95% SOH, due to high temperatures promoting more significant growth of the interfacial film or moderate film formation at room temperature enhancing interfacial thermal stability, the activation energies for both aged batteries increase, and the energy barrier at high temperatures is slightly higher than at room temperature; however, during the deep aging stage at 85% SOH, due to the degradation of active material components and the emergence of lithium plating characteristics, the energy barrier significantly decreases, with high-temperature-aged batteries exhibiting a greater reduction, highlighting the cumulative negative impact of prolonged high-temperature exposure on thermal safety. The research provides a core scientific basis for establishing a battery safety early warning and dynamic health management system covering the entire lifecycle. Full article

Air-to-underwater extremely low frequency (ELF) signal recovery requires a receiver that accounts for both cross-medium attenuation and impulsive interference. Seawater weakens the desired electromagnetic waveform while altering the tail behavior that remains observable within the receiver bandwidth. Conventional recursive robust filters normally choose their linearity parameters and output scale from empirical or data-driven rules and therefore do not explicitly incorporate this depth-dependent physical–statistical coupling. This work formulates the propagation-guided scaled recursive weighted myriad (PG-SRWMy) filter as a mathematically structured framework that links a propagation-evolving stochastic process model with robust nonlinear recursive estimation for reference-normalized underwater ELF recovery. The propagation state determines a depth-evolving effective stable-like description through a characteristic exponent and a dispersion parameter, and these stochastic descriptors are transformed into branch-specific initial linearity parameters of the recursive myriad estimator. The same propagation model yields a positive and bounded normalization transform for the reconstruction scale, while first-order sensitivity relations characterize the local effect of environmental-state uncertainty. The original SRWMy sample-wise recursion is retained for data-driven adaptation. Numerical experiments show that PG-SRWMy accelerates bilinear-parameter stabilization, lowers waveform-reconstruction error, and improves end-to-end reference-normalized signal-to-noise ratio (SNR) gain across changes in receiver depth and surface-side impulsiveness. The results support propagation-aware initialization as a mathematically structured and statistically interpretable route to depth-adaptive underwater ELF reception. Full article