Search Results (353)

Background: Prolonged exposure to moderate and loud noise is known to impair hearing; however, the safety of long-duration exposure to low-level sound, such as that encountered during everyday conversation, remains unclear. This study aimed to determine the effect of continuous exposure to sound at a 65 dB sound pressure level (SPL) on auditory processing. Methods: Auditory brainstem responses (ABRs) were recorded in C57BL/6 mice before and after a 1 h exposure to a continuous pure tone at 65 dB SPL. Changes in ABR thresholds, wave amplitudes, and latencies were analyzed across frequencies and time points. Correlations between amplitude and latency changes across ABR waves were also assessed. Results: Tone exposure induced a significant, frequency-specific increase in ABR thresholds, with a mean elevation of approximately 6 dB and a maximum shift of 15 dB. Significant reductions in amplitudes and prolongations of latencies were observed in Waves I–III, while Wave V amplitude remained relatively stable. A strong negative correlation between amplitude reduction and latency increase was found in Wave I, which progressively weakened from Wave II to Wave V. These functional changes persisted for up to three hours following exposure before gradually returning to baseline. Conclusions: Prolonged exposure to low-level sound at intensities typical of conversational speech can transiently impair auditory function and alter early neural processing in the auditory pathway. These findings suggest that sound levels commonly considered safe may still pose a risk when exposure is sustained, with implications for understanding hidden hearing loss and improving early diagnostic approaches. Full article

Gas-lift reverse circulation drilling technology is one of the typical “bottom-hole negative pressure” drilling technologies. This technology can significantly reduce wellbore circulation pressure loss, alleviate the bottom-hole pressure holding effect, and effectively lower the probability of lost circulation. The core theory underlying this technology is multiphase flow in the wellbore. Based on gas–liquid two-phase flow theory, this paper develops a method for calculating bottom-hole pressure during gas-lift reverse circulation. The effects of key operational parameters on bottom-hole pressure were analyzed. The results show that bottom-hole pressure decreases as gas injection rate increases and as the gas injection point deepens. Moreover, the deeper the gas injection point, the greater the pressure reduction. Compared with the results from gas-lift reverse circulation drilling design and monitoring software applied to a shale gas well in southern Sichuan, the two sets of data differ by approximately 3%. The proposed calculation method can predict bottom-hole pressure under gas-lift reverse circulation conditions, overcoming the low accuracy of empirical formulas traditionally used in such operations. This has significant implications for advancing gas-lift reverse circulation technology in oil and gas well drilling. Full article

Background: The photopic negative response (PhNR) of the full-field electroretinogram is a retinal ganglion cell-weighted functional signal increasingly proposed as a clinical biomarker. Despite extensive study across ocular and systemic diseases, its precise clinical role and incremental value remain incompletely established. Methods: This narrative review synthesizes key human studies of the photopic negative response, with emphasis on physiological basis, recording methodology, and clinical contexts in which PhNR may provide added functional insight. Results: In glaucoma, PhNR provides an objective measure of retinal ganglion cell dysfunction that correlates moderately with optical coherence tomography (OCT)-derived structural loss and visual field indices, but with substantial inter-individual variability. Its greatest clinical utility lies in early disease detection, cross-sectional functional assessment, and documenting short-term functional changes following intraocular pressure reduction, rather than longitudinal progression monitoring. Beyond glaucoma, PhNR reveals inner retinal dysfunction in systemic and genetic conditions, particularly idiopathic intracranial hypertension and diabetes, where retinal ganglion cells may reflect broader neurological or metabolic stress. Conclusions: PhNR is best viewed not as a standalone diagnostic or progression tool, but as a complementary functional biomarker that adds objective insight when structural imaging or psychophysical testing is limited or discordant. Its role aligns closely with the retina’s emerging function as a mirror of systemic and genetic disease, provided recordings are standardized and results interpreted cautiously. Full article

During drilling in stress-sensitive fractured formations, fracture aperture dynamically evolves with wellbore pressure fluctuations. The sealing layer often undergoes repeated cycles of sealing, destabilization, and re-sealing. Formulation selection based on a single metric or empirical selection cannot simultaneously satisfy multiple objectives, including pressure-bearing capacity, loss control, and dynamic adaptability. This study proposes an entropy-weighted TOPSIS and grey relational analysis method to optimize lost circulation formulations for stress-sensitive fractured formations. A hierarchical evaluation system is established with four criteria layers and eight indicator metrics. A baseline formulation framework is determined through static fracture sealing tests. Experimental data for different elastic-material systems are obtained using a self-developed DTDL dynamic fracture plugging apparatus. Indicator weights are objectively determined using the entropy weight method. A Grey–TOPSIS model is applied to compute grey relational closeness to the positive and negative ideal solutions, enabling formulation ranking and optimal scheme identification. A case study shows that the ternary elastic formulation with Rubber:Graphite:Net = 3:2:1 achieves the highest grey relational closeness and delivers the best overall sealing performance. The ranking remains unchanged when the distinguishing coefficient ρ varies from 0.1 to 0.9, confirming the robustness and feasibility of the proposed method. Compared with entropy-weighted TOPSIS and classical TOPSIS, the proposed method provides a more integrated treatment of the multi-metric data and better aligns the evaluation with the underlying sealing behavior in stress-sensitive fractures. Therefore, it leads to more reliable and comprehensive evaluation results for formulation selection. The results demonstrate that the proposed model provides reliable support and a methodological basis for formulation optimization in dynamic fracture loss control. Full article

This study experimentally investigates the combustion behavior of RP-3 aviation kerosene pool fires (300~800 mm) within a confined space, specifically focusing on the complex interaction between buoyancy-driven plumes and mechanical negative pressure ventilation. By integrating high-precision mass loss measurements with multiple characteristic parameters, this research uniquely characterizes the transition of energy feedback mechanisms under confined suction flow. Results show that ventilation enhances combustion intensity and compresses the fire cycle. For an 800 mm pool, the peak mass loss rate rose by 57.1%, from 16.71 g/s to 26.25 g/s. This enhancement stems from boundary layer thinning, which transitions the combustion from diffusion-controlled to kinetics-controlled. Ventilation also induces severe flame tilt with a non-monotonic trend. The tilt angle peaks at 84° for 600 mm pools but drops to 64° at 800 mm as buoyancy momentum increases. Additionally, an energy contrast of vertical cooling and horizontal heating was observed. Axial peak temperatures decreased by 20%, while downwind thermal radiation flux increased by up to 125%. The ventilation system essentially acts as a directional energy projector, shifting heat loads toward the downwind region. These findings support the optimization of fire safety and detection designs for industrial ventilation systems. This study experimentally investigates the combustion behavior of RP-3 aviation kerosene pool fires (300–800 mm) within a confined space, specifically focusing on the complex interaction between buoyancy-driven plumes and mechanical negative pressure ventilation. By integrating high-precision mass loss measurements with multi-point thermal and imaging diagnostics, this research uniquely characterizes the transition of energy feedback mechanisms under confined suction flow. Full article

Hemorrhagic shock remains a leading cause of preventable death in trauma, yet traditional vital signs may fail to reflect early blood loss before physiological compensatory mechanisms are no longer able to maintain hemodynamic stability. The Compensatory Reserve Measurement (CRM) algorithm offers early detection capability using physiological waveforms but requires testing with emerging wearable sensor technologies for operational deployment. This study tested the Epicore Epidermal Patch for Imperceptible Care (EPIC) wearable healthcare device (WHD) for CRM-based hemodynamic monitoring during progressive central hypovolemia induced by lower-body negative pressure (LBNP) to simulate hemorrhage. Twenty participants underwent progressive LBNP while photoplethysmography (PPG) signals were recorded from EPIC sensors placed at the clavicle and triceps alongside a clinical-grade finger pulse oximeter for reference. Signal quality, heart-rate accuracy, and CRM predictions were evaluated across multiple filtering approaches. The triceps placement achieved signal quality comparable to the pulse oximeter reference when Chebyshev Type II filtering was applied, as well as high heart-rate accuracy. CRM derived from the EPIC sensor placed at the triceps tracked compensatory trends during progressive hypovolemia, but prediction magnitudes were inaccurate compared to calculated CRM values. In contrast, the clavicle placement consistently performed poorly across all measurements, regardless of the signal-processing approach. These findings support the feasibility of soft, flexible wearable sensors for continuous hemorrhage monitoring at the triceps location in operational environments where traditional finger-based pulse oximetry is impractical. Full article

In this study, a thermally crosslinking clay-free weak gel water-based drilling fluid based on salt-responsive polymers and crosslinking agents was investigated as a promising and feasible strategy. Firstly, a salt-tolerant polymer was synthesized using N,N-dimethylacrylamide (DMAA), [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonopropyl)ammonium hydroxide (DMAPS), and acrylamide (AM). BPEI_10,000 was selected as the thermal crosslinking agent. The optimal crosslinking was achieved at 180 °C and 36% NaCl, with RMFL at 2.0% and BPEI_10,000 at 0.1%. Performance evaluation demonstrated that the crosslinking between RMFL and BPEI_10,000 could enhance the AV, PV, and YP of the RMFL(BPEI_10,000)/CF-WBDFs after aging at 180 °C for 16 h and reduce FL_API. The RMFL(BPEI_10,000)/CF-WBDFs exhibited appropriate shear-thinning behavior, viscoelasticity, thixotropy, and recoverable viscosity under high-temperature, high-salinity, and high-pressure conditions. Mechanism analysis revealed that RMFL and BPEI_10,000 could form a predominantly negatively charged, three-dimensional crosslinking weak gel at high temperatures. The crosslinking weak gel could form dense filter cakes, improving rheological properties and reducing filtration loss of CFWBDFs in high-temperature, high-salinity environments. This paper proposed a novel method to address the technical challenge of rheological performance failure of CFWBDFs, offering valuable insights for subsequent investigations. Full article

Background/Objectives: With increasing survival rates following oncologic mastectomies, loss of breast sensation can negatively impact a patient’s quality of life. Methods: PubMed, Embase, and Web of Science were searched in April 2025 for studies reporting sensory outcomes after neurotized breast reconstruction. Eligible studies included patients undergoing autologous or implant-based reconstruction with any neurotization technique. Forty studies were included, and outcomes involved objective sensory testing (e.g., Semmes-Weinstein monofilaments, pressure-specified sensory devices, and thermal thresholds) and patient-reported quality of life (e.g., BREAST-Q). Results: Neurotization consistently accelerated and improved recovery of tactile, thermal, and protective sensation compared with non-neurotized controls, particularly in DIEP and TRAM flaps. Direct coaptation was most frequently employed, while nerve allografts, conduits, and autologous grafts offered effective alternatives when direct repair was not feasible. Implant-based reconstructions using allografts also demonstrated significant improvements in the nipple–areola complex and breast skin sensation. Across studies, earlier and more uniform sensory return was reported, with improved sensation often associated with high patient satisfaction and quality of life. Conclusions: The preponderance of observational evidence suggests that nerve coaptation, whether by direct suture, conduit, allograft, or autograft, represents a promising adjunct to breast reconstruction in both autologous and implant-based reconstruction. However, many studies were retrospective in design, had small sample sizes, and lacked randomization. Full article

Modern high-pressure turbine (HPT) nozzle guide vanes (NGVs) operate under non-uniform inlet conditions, including hot streaks and swirl, which can induce complex flow phenomena and uneven thermal loading. These effects, particularly at the hub-vane corner, can compromise NGV durability, yet the combined influence of swirl and film cooling remains underexplored. The objective of this study is to investigate the aerothermal behaviour of contoured first-stage NGVs under varying swirl intensities and directions to improve understanding of hub and corner thermal protection and failure mechanisms. Steady, compressible RANS simulations were conducted with the k-ω SST turbulence model. A vane with a contoured hub and multiple film cooling rows was designed and analysed under axial and swirling inflows, both clockwise and counter-clockwise, with swirl numbers of Sn = ±0.2 and ±0.4. Axial flow achieved the highest area-averaged film cooling effectiveness (FCE) of 0.617. Negative swirl (Sn = −0.4) improved suction-side corner FCE to 0.215 but reduced pressure-side cooling, whereas positive swirl (Sn = 0.4) improved pressure-side cooling but reduced suction-side FCE to 0.043. Corner temperatures under positive swirl reached 1780 K, consistent with promoting failure, while negative swirl reduced corner temperatures to 1516 K. Aerodynamic losses increased with swirl, with negative swirl generating 5.78% higher total pressure losses than the axial baseline. Swirl altered the corner vortex topology, affecting boundary layer interactions and local heat transfer. These results highlight a trade-off between thermal protection and aerodynamic efficiency, emphasising that optimising NGV performance requires careful design of hub cooling and consideration of swirl direction and intensity. Full article

This study develops a Constraint-Driven Model of Intelligence to explain the emergence of structured meaning in complex systems, reconciling probability and cybernetics. It applies a conceptual–analytic procedure, conducted entirely through logical reasoning and theoretical analysis, without empirical measurement, data acquisition, experimental manipulation, or statistical testing, and is therefore methodologically separate from empirical artificial intelligence research. Phenomena such as model collapse are cited as theoretical instances for epistemic argumentation, without asserting empirical verification. Building on Émile Borel’s Infinite Monkey Theorem, which demonstrates the theoretical inevitability of order in unbounded stochastic processes, and Gregory Bateson’s principle of negative explanation, which defines structure as the result of systematically eliminated alternatives, the analysis formalizes how constraints break ergodicity and generate asymmetry. Shannon’s entropy quantifies the informational effects of constraints, while Simon’s bounded rationality and Turing’s algorithmic limits show how cognitive and computational boundaries produce tractable outcomes. Applied to modern AI, the model accounts for model collapse in recursive training, showing that the loss of asymmetric constraints produces low-entropy, repetitive outputs, demonstrating the epistemic necessity of constraint regulation. Comparing probabilistic and cybernetic accounts of emergence, the study shows that structured intelligence arises not from stochastic exploration alone, but from bounded, recursive, selective processes. This model is transdisciplinary, formalizing how constraints from socioeconomic pressures to subcultural circulation shape diversity, innovation, and functional asymmetry, establishing a generalizable cybernetic epistemology for the generation of structured intelligence and meaning across domains. By formalizing these concepts through set-theoretic derivations and integrative synthesis, this non-empirical model advances a cybernetic epistemology, separate from quantitative AI evaluations or experimental designs. Full article

Puccinia striiformis f. sp. elymi (Pse) is a specialized forma specialis of stripe rust infecting Elymus dahuricus, yet its mitochondrial evolution remains poorly understood. In this study, we assembled the complete mitogenome of Pse using PacBio HiFi sequencing, yielding a circular mitogenome of 72,952 bp. This reveals a striking asymmetric evolutionary pattern with a 28.34% genomic contraction compared to the wheat stripe rust P. striiformis f. sp. tritici (Pst-CYR32). Our analysis demonstrates that this streamlining is strictly driven by a massive and systematic loss of mitochondrial introns. The Pse mitogenome exhibits negative GC-skew (−0.0184) consistent with strand-asymmetric mutational pressure, while maintaining a strictly conserved and syntenic complement of all 14 core protein-coding genes (PCGs), alongside 24 tRNAs and 2 rRNAs. Phylogenomic analysis positions Pse as sister to the Pst clade with strong support (100% bootstrap). A 748-bp SNP cluster within nad4 (14.2% sequence divergence versus 3.1% genome-wide average) provides a candidate molecular marker for lineage differentiation, pending population-level validation. This study establishes a genomic foundation for investigating mitochondrial reductive evolution in host-specialized rust lineages, highlighting the dynamic role of introns in driving organellar genome size variation. Full article

This study examines the carbonation behavior and CO₂ storage potential of a Ca-rich alkali-activated binder produced entirely from industrial residues-ladle furnace slag (LFS), coal ash (CA), and cement kiln dust (CKD). The system was designed as a one-part alkali-activated material (AAM), with CKD acting as an internal activator, and subjected to ambient curing, water curing, and accelerated CO₂ curing at ambient pressure. Phase evolution, microstructural development, and pore-structure characteristics were investigated using X-ray diffraction, FTIR spectroscopy, DSC–TG analysis, scanning electron microscopy, and X-ray micro-computed tomography, together with measurements of density, water absorption, and compressive strength. Loss-on-ignition measurements combined with chemical analysis were further used to quantify CO₂ uptake and evaluate the degree of carbonation of the binder system. CO₂ curing fundamentally altered the reaction pathway of the binder, shifting it from hydration-dominated to carbonation-controlled phase evolution, leading to the decomposition of calcium-bearing hydrates and complete carbonation of non-hydraulic γ-belite with the formation of vaterite, aragonite, and calcite. These transformations induced pronounced microstructural densification, reflected in a near-doubling of compressive strength (>48 MPa), increased apparent density, reduced water absorption, and simplified pore-network topology. A preliminary carbon footprint assessment indicates that the production of 1 m³ of the developed LFS–CA–CKD concrete generates about 14.36 kg CO₂-eq, while the carbonation process enables significant CO₂ sequestration, resulting in a net negative carbon balance. The results demonstrate that controlled carbonation is an effective post-treatment strategy for waste-derived alkali-activated binders, enabling simultaneous performance enhancement and permanent CO₂ sequestration. Full article

This study investigates uncertainty quantification for field-level ship hull surface pressure predictions using a U-Net-based data-driven model. A speed-conditioned U-Net is trained on a large CFD dataset covering multiple ship types and velocity conditions to predict pressure distributions on hull surfaces. The model outputs the mean pressure and log-variance at each grid location using a negative log-likelihood loss, allowing aleatoric uncertainty to be estimated, while epistemic uncertainty is quantified by a deep ensemble of independently trained models. The reliability and calibration of the predicted confidence intervals are evaluated at the field level. The results show that calibration stabilizes as ensemble size increases, and coverage slightly exceeds nominal confidence levels. Uncertainty decomposition indicates that aleatoric uncertainty dominates and is insensitive to ensemble size, while epistemic uncertainty primarily affects calibration. Elevated uncertainty is consistently observed near free-surface regions around the bow and stern, reflecting increased prediction difficulty. These findings demonstrate the effectiveness of deep-ensemble-based uncertainty quantification for CFD-driven pressure field prediction models. Full article

Addressing the issue of boundary layer separation and flow instability caused by shock wave–boundary layer interaction in supersonic compressor cascades, this work presents a novel aerodynamic design and optimization method for supersonic cascades. This method is based on a design philosophy of enhancing control over the shock wave and boundary layer by employing a blade channel with a curvature-continuous profile. An aerodynamic redesign and optimization methodology was conducted on the ARL-SL19 supersonic cascade, aiming to improve its aerodynamic performance and widen the stable operating range. The results indicate that for a low-loss diffusing channel, the design principle for the suction surface profile involves controlling the shock strength via the curvature of the forward section, while the aft section should feature a smooth and negative curvature variation. This approach facilitates the control of the boundary layer flow, thereby improving the overall aerodynamic performance of the supersonic cascade. Compared to the baseline, the aerodynamically optimized cascade demonstrates a 10.74% reduction in the total pressure loss coefficient at the design point. Furthermore, its performance at off-design conditions is also significantly enhanced: the near-stall total pressure loss coefficient is reduced by 6.66%, the maximum total pressure ratio is increased by 6.32%, and the stable operating range with low flow loss is considerably extended. Full article

Carbapenems are essential for the treatment of severe infections caused by Gram-negative bacteria, particularly in critically ill and immunocompromised patients. However, the global rise of carbapenem-resistant Enterobacterales (CRE), Pseudomonas aeruginosa, and Acinetobacter baumannii has significantly eroded their effectiveness, and the phenomenon is now recognized as a major public health threat. Resistance is driven by the complex and evolving interplay of enzymatic and non-enzymatic mechanisms, occurring within highly successful clonal lineages and mobile genetic platforms. This review summarizes advances since 2020 in the molecular basis of carbapenem resistance, integrating enzymatic mechanisms across Ambler classes A, B, C, and D with emerging non-enzymatic contributors, including porin remodeling, efflux pump upregulation, target-site alterations, and outer-membrane adaptations. Particular attention is given to adaptive genome dynamics, such as IS26-mediated gene amplification, plasmid multimerization, and heteroresistance, that generate unstable resistance phenotypes and complicate routine susceptibility testing. Newly introduced β-lactam/β-lactamase inhibitor combinations exert distinct selective pressures: ceftazidime–avibactam favors KPC Ω-loop variants and permeability defects, often restoring carbapenem susceptibility, whereas meropenem–vaborbactam and imipenem–relebactam resistance is driven mainly by porin loss and β-lactamase gene amplification. Cefiderocol resistance is multifactorial, frequently involving impaired siderophore uptake and heteroresistance, while sulbactam–durlobactam remains active against OXA-producing A. baumannii but is compromised by metallo-β-lactamases and PBP3 alterations. Carbapenem resistance is increasingly characterized by convergent, multi-layered adaptations that undermine both established and novel therapies. While high-level randomized evidence remains limited for some resistance mechanisms, emerging mechanistic, microbiological, and clinical data support the need for mechanism-aware diagnostics, repeated susceptibility assessment during therapy, and stewardship strategies informed by resistance biology. Integrating molecular context into routine practice will be critical to preserving emerging treatment options and limiting the global impact of carbapenem resistance. Full article