Search Results (18,528)

Background: Anterior ischemic optic neuropathy (AION) is a potentially vision threatening disorder that affects middle-aged and elderly individuals. The pathogenesis of the disease remains incompletely understood. However, the most universally accepted hypothesis suggests that a transient reduction in optic nerve head (ONH) perfusion, secondary to hypovolemia, nocturnal hypotension, or small-vessel disease, results in ischemic infarction of the anterior portion of the optic nerve. Case presentation: We present the case of a 61-year-old male patient with a history of arterial hypertension, type II diabetes mellitus, generalized atheromatosis, femoral bypass and stent implantation for chronic ischemia in his left leg, followed by brachial artery dissection that needed a prompt vascular intervention; he presented visual acuity loss in both eyes (BE), with the left eye (LE) being more affected than the right eye (RE). A complete ophthalmologic check-up was performed, and it revealed best-corrected visual acuity (BCVA) RE 0.5 Snellen, LE light perception, normal intraocular pressure (IOP), BE papillary edema and arteriovenous abnormalities. Visual field (VF) examination revealed RE inferior altitudinal defect and LE preabsolute scotoma. The diagnosis of BE anterior ischemic optic neuropathy and hypertensive retinopathy stage II was formulated. Following the aforementioned surgical procedures meant optimizing the patient’s critical vascular status, subsequent management of NA-AION systemic risk factors, along with implementing important lifestyle changes. No further cardiovascular events occurred, and visual field parameters remained stable at the three-year follow-up. Conclusions: Non-arteritic anterior ischemic optic neuropathy (NA-AION) remains a topic of interest for both ophthalmologists and neurologists worldwide. When confronted with a high-risk cardiovascular patient, a rapid and thorough systemic evaluation may prove beneficial. This management strategy could potentially contribute to maintaining a stable systemic outcome, despite major cardiovascular threats. Full article

In the thermal insulation winding process of solid rocket motors, the roller-tape contact pressure is a critical factor determining bonding quality. However, accurately predicting this pressure is challenging due to the complex three-dimensional contact involving a thin, nearly incompressible rubber tape and an elliptical concave press roller. This paper proposes a theoretical model extending the classical elastic foundation model by incorporating correction strategies to account for material incompressibility and geometric confinement. A finite element (FE) model was developed to simulate the contact and verified against Hertz theory. Two key parameters of the theoretical model were calibrated using the FE results and justified through a parametric study on Poisson’s ratio and a theoretical analysis of the contact half-width. The theoretical predictions of deformation, contact pressure distribution, and pressing force agree well with the FE results under different applied displacements and mandrel radii without parameter recalibration, demonstrating the model’s generality. Experimental validation employing hybrid inverse analysis confirms the model’s global accuracy, yielding <11% relative error between the predicted and measured pressing forces. This study establishes a theoretical foundation for pressure control in the winding process and provides insights into contact problems for thin elastic layers with high Poisson’s ratios (≥0.45). Full article

Plastic waste has become a serious global issue. Thermal treatment of waste PET faces critical drawbacks including severe reactor clogging and low-value oxygen-rich bio-oil, restricting large-scale chemical recycling. Co-pyrolysis with hydrogen-rich low-density polyethylene (LDPE) over modified zeolite provides a viable route to overcome these barriers. In this study, reaction parameters including temperature, plastic/catalyst ratio and PET/LDPE ratio were optimized, and Fe-Ni bimetallic modified HZSM-5 was fabricated via impregnation to boost monocyclic aromatic hydrocarbons (MAHs) production. LDPE served as a hydrogen donor to facilitate PET deoxygenation via synergistic effects. At 550 °C with a plastic/catalyst ratio of 1:4 and PET/LDPE ratio of 2:3, the liquid yield hit 80.2%, and all detectable organic compounds in the liquid phase identified by GC–MS were aromatic hydrocarbons. Among all prepared mono- and bimetallic zeolites, 3Fe7Ni/HZ delivered optimal MAHs selectivity at 80.5%. This 20% promotion over unmodified HZSM-5 stems from balanced metal dispersion and tuned acid sites unique to Fe–Ni co-loading. This work offers a feasible strategy for converting waste plastics into high-value aromatics and further trials with varied metal contents will be needed to extend industrial applicability. Full article

Rectangular reinforced concrete (RC) hollow bridge piers may exhibit significant shear participation after flexural cracking and yielding, whereas their seismic responses are commonly evaluated using flexure-dominated numerical models. This study investigates the effects of axial–flexure–shear interactions on the cyclic response and seismic fragility of rectangular RC hollow bridge piers. Cyclic loading tests on seven one-eighth-scale specimens were analyzed to characterize the effects of the shear-span ratio and reinforcement configuration. The experimental results were then used to assess a conventional flexure model and an axial–flexure–shear interaction model, denoted as AFSI–MBTEM. Full-scale piers with heights of 16, 24, and 32 m were subsequently analyzed under cyclic loading and representative near-fault ground motions. Finally, 7200 nonlinear time-history analyses were conducted using 80 records divided into non-pulse and short-, medium-, and long-period pulse-like groups, while seismic fragility curves were developed using displacement ductility as the demand parameter. The tests indicated flexure-dominated but distinctly shear-sensitive behavior, particularly for specimens with low shear-span ratios. Compared with the flexure model, AFSI–MBTEM reproduced pinching, post-peak deterioration, and hysteretic energy more accurately, reducing the mean absolute error in hysteretic energy from 23.57% to 13.29%. For the full-scale piers, model differences generally decreased as the pier height and shear-span ratio increased together, although the effects on large-deformation stability and seismic response remained configuration- and ground-motion-dependent. AFSI–MBTEM predicted higher fragility in 46 of the 48 height–motion–damage-state comparisons. At the upper analyzed intensity of PGA = 1.5 g, it also produced higher DS4 exceedance probabilities in the examined critical cases. Within the investigated section configurations, axial-load ratios, and coupled height–shear-span cases, the results indicate that neglecting axial–flexure–shear interactions may lead to nonconservative fragility estimates, particularly for configurations with greater shear participation. Full article

Polymer-based three-dimensional (3D) printing has evolved from a prototyping approach toward a manufacturing strategy with emerging clinical relevance for individualized dosage forms, local drug depots, microneedle systems, microfluidic cartridges, biosensor housings and integrated theranostic platforms. Its value arises from the simultaneous control of polymer chemistry, device architecture and process history: infill, porosity, shell thickness, crosslink density, swelling, degradation and surface chemistry can be used as design variables rather than incidental manufacturing outcomes. This review critically synthesizes recent progress in polymer-enabled additive manufacturing for drug delivery and diagnostic applications, with emphasis on thermoplastic and biodegradable polymers, hydrogels, photopolymers, elastomers, conductive composites, stimuli-responsive networks and bioinks. Fused deposition modelling, hot-melt extrusion, semi-solid extrusion, vat photopolymerization, two-photon polymerization, selective laser sintering, binder jetting and inkjet/aerosol jet approaches are compared in relation to drug stability, diagnostic compatibility, feature resolution, scalability and regulatory risk. Particular attention is given to geometry-controlled release, multi-drug printlets, microneedles, implants, scaffold-based local therapy, microfluidic diagnostics, electrochemical biosensors and wearable or closed-loop systems. Translation is discussed through quality-by-design, critical material attributes, critical process parameters, process analytical technology, extractables/leachables, sterilization, point-of-care manufacturing, data integrity and clinical evidence requirements. Future advances should connect polymer–process–property relationships with clinically meaningful use cases, verified quality attributes and realistic regulatory pathways. Full article

Antimicrobial resistance (AMR) in Gram-negative pathogens represents a critical global health challenge. Combining cefepime with novel β-lactamase inhibitors (enmetazobactam, taniborbactam, zidebactam, and nacubactam) revitalizes the role of this fourth-generation cephalosporin in contemporary therapy. We present a narrative review according to the Scale for the Assessment of Narrative Review Articles (SANRA) criteria, summarizing the existing literature regarding new cefepime combinations with β-lactamase inhibitors. Based on 68 identified studies, data were structured by molecule. Each section explores in vitro activity, preclinical in vivo data, PK/PD parameters, clinical evidence, and dosage. Findings demonstrate that these inhibitors successfully restore cefepime’s efficacy against diverse resistance mechanisms, notably ESBLs, AmpC, KPC, OXA-48, and metallo-β-lactamases. “Cefepime 2.0” therapies expand the therapeutic armamentarium against severe multidrug-resistant infections, offering vital carbapenem-sparing strategies. Because they possess distinct microbiological spectra, these agents serve complementary rather than interchangeable roles. Their clinical success demands targeted integration into antimicrobial stewardship programs to optimize efficacy and safely reduce carbapenem dependence. Full article

Wide- and narrow-band composite-axis servo systems in inter-satellite laser communication face critical challenges in balancing high-precision dynamic tracking and strong robust anti-disturbance performance under the coupling effect of high-speed inter-satellite relative motion and multiple strong disturbances. To address this issue, this paper proposes a composite control method integrating adaptive non-singular terminal sliding-mode control and a nonlinear extended state observer. First, a full-link dynamic model covering electromechanical coupling and inter-axis disturbance transmission is constructed to accurately quantify the disturbance characteristics of coarse- and fine-tracking loops. Second, a third-order nonlinear extended state observer is designed to realize real-time high-precision estimation and feedforward compensation of lumped disturbances. On this basis, a self-consistent adaptive non-singular terminal sliding-mode control law is formulated. Under the explicitly stated observer-residual and reaching-phase assumptions, the ideal continuous model provides finite-time convergence of the sliding variable and tracking error. Finally, a wide- and narrow-band cooperative strategy based on error frequency division is introduced to achieve complementary performance between large-stroke coarse tracking and ultra-high-precision fine tracking. Numerical simulations yield a steady-state tracking-error point estimate of 0.30 μrad and a 20 dB disturbance-suppression bandwidth of 1200 Hz. In the semi-physical dynamic-tracking test, the proposed controller limits the peak error to 1.2 μrad; the instrument-only expanded uncertainty of the detector output is estimated as 0.12 μrad (coverage factor k = 2). At the reported evaluation points, the proposed method outperforms PID, conventional sliding-mode control, and linear active-disturbance-rejection control. Deterministic robustness simulations also show smaller tracking errors and shorter recovery times under parameter perturbation, actuator saturation, and temporary link occlusion. No Monte Carlo loss-of-lock probability is claimed. Full article

High-speed railway track–bridge systems (HSRTBSs) in near-fault high-seismicity regions face combined threats from pulse-type seismic excitations, vertical earthquake components and track defects, which may trigger structural damage and deterioration of track regularity. This paper establishes refined OpenSEES coupled numerical models for a typical 32 m simply supported girder bridge equipped with CRTS II slab ballastless track, considering both conventional spherical steel bearings and friction pendulum bearings (FPBs). Nonlinear time-history analyses are performed with near-fault pulse-like and far-field non-pulse ground motions to explore the influences of peak ground acceleration (PGA), vertical-to-horizontal acceleration ratio (αVH), and CA mortar void length. The results demonstrate hierarchical controlling effects of these parameters. PGA dominates the overall seismic response; sliding layer damage follows the sensitivity sequence PGA > αVH > CA mortar void, whereas post-earthquake traffic capacity degradation obeys PGA > CA mortar void > αVH. Near-fault pulse-like ground motions produce more severe structural damage compared with far-field inputs. FPB isolation yields a maximum pier-top seismic reduction ratio of 86.73% and effectively mitigates structural deformation, but cannot eliminate track irregularity originating from CA mortar void defects. Conditional on the 0.2 g seismic level and the given structural configuration adopted in this study, αVH = 0.65 and the 1.95 m critical CA mortar void length for longitudinal track constraint failure can serve as reference values, though they are not universally applicable for all track–bridge systems. This work provides insights for seismic design, CA mortar defect remediation and post-earthquake traffic assessment of near-fault isolated HSRTBSs. Full article

This comprehensive review systematically examines the fundamental and contemporary concepts underlying the Toms effect—the phenomenon of turbulent drag reduction (DR) induced by the addition of minute concentrations of high-molecular-weight linear polymers to turbulent flows. The evolution of scientific understanding is traced from the classical studies of the mid-twentieth century to contemporary machine-learning-based approaches. The influence of four key parameters is examined in detail: the dimensionless solvent viscosity ratio $\beta$, Reynolds number $Re$, conformational chain length $L_c/MW$, and macromolecular relaxation time $\lambda$. Polymer concentration $C$ is treated as an independent control variable through which the values of these four parameters are partially determined. The principal physical mechanisms at the molecular and hydrodynamic levels are described. The capabilities of numerical modeling approaches (DNS, LES, and RANS) are critically reviewed, along with promising directions for the application of artificial intelligence. Finally, practical guidelines are proposed for validating and interpreting experimental and numerical drag-reduction data over a broad range of hydrodynamic conditions. Full article

Roof-contact backfilling is a critical determinant of stope stability in cut-and-fill mining, and the rheological properties of backfill slurry decisively influence the quality of roof contact. To investigate the flow characteristics of unclassified tailings backfill slurry and their effect on rheological parameters, this study uses the Daye Iron Mine as its engineering case. It adopts a combined laboratory and numerical simulation approach. The physicochemical characteristics of the unclassified tailings and the rheological behavior of the slurry were systematically characterized using particle-size analysis, density measurements, spreadability tests, and rheometer measurements. Subsequently, a numerical model of the L-type flow tester was developed in COMSOL Multiphysics (6.4) to simulate the flow process at varying concentrations. Based on the simulation results, a Gaussian process regression (GPR)-based inversion model for rheological parameters was proposed, and the predictive performance of different kernel functions was compared and evaluated. Finally, the existing backfilling scheme at the Daye Iron Mine was optimized based on the obtained rheological characteristics to improve the roof-contact rate. The results indicate that the unclassified tailings from the Daye Iron Mine have a median particle size of 12.1 μm and a density of 2855 kg·m⁻³, with CaO, Al₂O₃, and MgO as the primary active components. Under the same cement-to-tailings ratio, slurry flowability decreases markedly with increasing concentration. The rheological curves exhibit three stages, with the third conforming to the Bingham model; both yield stress and viscosity increase exponentially with concentration. Evaluation of the inversion results demonstrates that the GPR model with the Rational Quadratic (RQ) kernel achieves optimal performance. The recommended slurry concentration for the Daye Iron Mine is determined to be in the range of 69–71%, and the recommended spacing between filling pipelines is 13.34–18 m. This study reveals the flow evolution patterns of unclassified tailings backfill slurry, demonstrates the potential of the GPR-based inversion approach, and optimizes the roof-contact backfilling scheme, offering a scientific reference for flow characterization and backfill optimization in analogous mining operations. Full article

Timely and accurate defect classification is critical for ensuring product quality and safety in industrial inspection scenarios. The widespread deployment of Internet of Things (IoT) devices equipped with sensing, computing, and communication capabilities has promoted the development of AI-enabled industrial applications. However, conventional AI approaches typically rely on centralized data collection and processing, which become impractical in real-world IoT environments due to growing privacy concerns and constrained device resources. To address these challenges, this paper proposes a communication-efficient adaptive federated learning algorithm for heterogeneous defect classification tasks. The proposed approach jointly accelerates the training process through three mechanisms: (i) adaptive local updates that balance communication and computation overheads; (ii) parameter compression that trades off communication cost against model accuracy; (iii) joint bandwidth and computation-power allocation that optimizes per-round communication and computation time across participating devices. We further analyze the joint effects of these three mechanisms and provide a convergence analysis. Extensive simulations show that the proposed method achieves competitive classification accuracy while reducing single-round training time by up to 70%. Full article

Background: Isavuconazole, a broad-spectrum triazole antifungal, exhibits high lipophilicity and extensive plasma protein binding, properties that may predispose it to sequestration within extracorporeal membrane oxygenation (ECMO) circuits. This study aimed to characterize the pharmacokinetics (PK) of isavuconazole and to evaluate drug sequestration within the ECMO circuit in critically ill patients receiving ECMO support. Methods: We conducted a prospective, exploratory, single-center observational study including critically ill patients receiving ECMO (veno-venous (VV) or veno-arterial (VA)) and treated with intravenous isavuconazole. Serial blood samples were collected simultaneously from the patient’s arterial line and from pre- and post-membrane oxygenator sampling sites. Non-compartmental analysis was performed on arterial line samples to estimate PK measures, and concentration differences across sampling sites were analyzed to estimate circuit-related drug loss. PK/pharmacodynamic (PD) target attainment was assessed using established efficacy thresholds (AUC_0–24/MIC ≥ 25 and Cmin > 2 mg/L). Results: A total of 41 plasma samples from 3 critically ill patients (2 VV-ECMO, 1 VA-ECMO) were included in the analysis. Limited, component-specific isavuconazole loss was observed in tubing and connectors (6.62% ± 20.8%, p = 0.294) and across the entire ECMO circuit (7.74% ± 20.2%, p = 0.211). Likewise, no relevant concentration difference was detected across the membrane oxygenator (0.849% ± 6.15%, p = 0.642). Interindividual variability was observed across PK parameters, particularly in measures of elimination and distribution. All patients achieved predefined PK/PD efficacy targets, with mean Cmin and AUC_0–24/MIC of 3.07 ± 0.261 mg/L and 85.3 ± 4.03, respectively, and none exceeded the established toxicity threshold. Conclusions: Preliminary results showed variable concentration differences across ECMO sampling sites, with no consistent pattern of isavuconazole loss across the ECMO circuit under the conditions evaluated. All patients achieved predefined PK/PD efficacy targets using currently recommended dosing regimens; however, interindividual PK variability was observed, supporting the potential value of therapeutic drug monitoring (TDM) to guide individualized dosing decisions in this population. Larger population PK studies are warranted to further characterize determinants of isavuconazole exposure during ECMO support and refine evidence-based dosing strategies. Full article

Accurate remaining useful life (RUL) prediction of lithium-ion batteries is critical for reliable operation of the system. The performance evolution of lithium-ion batteries shows long-range dependence and capacity regeneration. However, existing performance evolution models fail to properly consider the joint effect of long-range dependence and capacity regeneration, and consequently have a deficiency in mechanism interpretability, which may limit the prediction accuracy of RUL. To address this gap, this paper separately characterizes the degradation and regeneration processes of the discharge capacity, and proposes a novel discharge capacity evolution model incorporating fractional Brownian motion and the Poisson capacity regeneration process. For the estimation problem of the model parameters caused by the Poisson regeneration, we approximately transform the proposed model to one with independent increments according to the weak convergence theorem, and then develop a maximum likelihood estimation method. From a limit perspective and using the theory of total probability, we derive the distribution of RUL, and provide the point estimation of RUL. Finally, we utilize the data set of lithium-ion batteries produced by NASA to verify the effectiveness of the proposed method, and the mean absolute errors of the proposed method are declined by at least 24% compared to the existing methods. Full article

Environmental stress cracking (ESC) severely limits the long-term reliability and engineering application of polycarbonate (PC)-based materials. In this work, a universal strategy is proposed to enhance the ESC resistance of PC by introducing crack-termination sites, enabling efficient suppression of crack propagation without compromising the intrinsic mechanical properties of PC. A quantitative evaluation framework based on a constant-strain method is established, and the critical strain rate (η) is defined as a key parameter for assessing ESC behavior under chemo-mechanical coupling. Systematic experiments reveal that chain entanglements, rubbery phases, and crystalline region can effectively increase η value of PC-based materials, demonstrating their superior crack-termination efficiency. Notably, the β-crystalline phase in PBT and microcrystalline domains induced by ethylene–acrylate copolymer tougheners are identified as the most efficient crack-termination structures, providing continuous energy-dissipation pathways and effectively halting crack propagation. This work not only establishes a practical and quantitative approach for evaluating ESC performance but also provides an integrated material-modification strategy. The proposed concept of crack-termination sites offers new insight into the development of high mechanical performance and ESC resistance PC-based polymer systems for advanced industrial applications. Full article

The increasing demand for sustainable and environmentally synthesis routes has driven significant interest in biogenic precursors for nanomaterial fabrication. Among these, egg-derived materials—including eggshell, eggshell membrane (ESM), egg white, and egg yolk—have emerged as versatile, low-cost, and multifunctional resources for green nanotechnology. This review provides a comprehensive and critical analysis of the physicochemical properties and functional roles of egg-derived components in nanomaterial synthesis. A comparative evaluation of egg-derived and conventional synthesis methods is presented, highlighting the trade-off between environmental sustainability and control over physicochemical parameters. Egg-derived approaches offer reduced toxicity, lower energy consumption, and intrinsic functionalization, but remain limited by compositional variability, reduced reproducibility, and challenges in process scalability. Furthermore, an application-oriented framework is proposed for selecting appropriate egg-derived precursors based on material type, targeted functionality, and processing constraints. The review also identifies key limitations, including mechanistic uncertainties, organic residue formation, and regulatory considerations, and outlines future research directions focused on process standardization, in situ characterization, and hybrid synthesis strategies. Full article