Search Results (8,802)

Antiretroviral therapy (ART) is essential for controlling human immunodeficiency virus (HIV) infection, requiring strict daily adherence for lifelong viral suppression. However, this continuous oral dosing results in persistent exposure of the gastrointestinal tract (GIT), raising the need to investigate the effects of TC-ART (Tri-combination Abacavir, Dolutegravir, Lamivudine–ART) on epithelial integrity, barrier recovery mechanisms, and surface barrier architecture. TC-ART exposure (125 µM to 4000 µM) showed marked alterations in transepithelial resistance, permeability, and wound-healing abilities even at sub-cytotoxic doses. The dose exposure range at the mid-dose level showed the highest transcriptional activity, characterized by a downregulation of junctional genes [claudins (CLDNs), desmoglein’s (DSGs), and junctional plakoglobin (JUP)] and signaling mediators [the signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase 1 and 3 (MAPK1/3), and catenin beta 1 (CTNNB1)], along with reduced IL-9 expression that is linked to mucin loss. These transcriptional changes were consistent with structural findings, including partial transepithelial electrical resistance (TEER) recovery followed by a decline, delayed wound closure, and waning of the apical mucin layer in a dose-dependent manner. However, several cytokines, like IL-2 and IL-6, showed increased secretion despite lower transcriptional levels, suggesting alternative regulatory control during early stress responses. Together, these results support that TC-ART exposure alters epithelial responses in a way that may transition from early adaptation to signs of impaired recovery, leading to a gradual decline in mucosal barrier function. Such concentration- and time-dependent epithelial stress may contribute to gastrointestinal disturbances observed in treated HIV populations, emphasizing the need for incorporating intestinal epithelial health endpoints in drug safety evaluations. Full article

This study presents a multi-methodological approach combining subsurface characterization with dynamic structural assessment to evaluate Soil–Structure Interaction (SSI) mechanisms at the Palazzo Centrale. The 3D Electrical Resistivity Tomography (ERT) and active Multichannel Analysis of Surface Waves (MASW) results were compared with a lithostratigraphic core log to outline the subsurface framework. The stratigraphic framework mapped geotechnical heterogeneities within the upper 6.0 m, where a low-resistivity anomaly (≤1 log(Ω·m)) outlines a mechanically weakened, water-saturated cover deposit overlaying the basaltic lava. This characterization provides the physical baseline useful for interpreting the site response. In this framework, the ambient vibration recordings performed at the free-field sites exhibit a flat Horizontal-to-Vertical Spectral Ratio (HVSR) response within the 1.0–10.0 Hz range, whereas a localized stratigraphic peak emerges at higher frequencies near 15.0 Hz, particularly evident in the building’s courtyard. The building resonance frequency peaks, derived from the Horizontal-to-Horizontal Spectral Ratio (HHSR) analysis at 3.74 ± 0.09 Hz (NS) and 3.58 ± 0.22 Hz (EW), do not overlap with the site resonance frequencies, demonstrating a dynamic decoupling between the soil and the building within the low-to-medium frequency domain. Conversely, the secondary stratigraphic peak near 15.0 Hz overlaps with higher-order structural frequencies tracked in the HHSR datasets. Given the localized nature of this stratigraphic peak and the involvement of higher-order structural modes, this overlap suggests a limited, localized high-frequency amplification confined to specific architectural components, rather than a global site-structure hazard. Furthermore, torsional analysis reveals significant effects within the 3.8–4.0 Hz frequency band, targeting the North-East corner (peak value of 2.85 at station A4), indicating a localized dynamic anomaly due to structural heterogeneities. Overall, this multi-method approach proves highly effective for non-invasive structural diagnostics, establishing a rigorous physical reference that could be successfully integrated into future preventive conservation frameworks and routine monitoring protocols for ancient architectural heritage. Full article

Intrinsically self-sensing cementitious composites offer a promising basis for continuous structural health monitoring. Their electrical response, however, is strongly affected by reversible moisture change and freeze–thaw exposure. This study presents a computational proof-of-concept for the AI-driven design of a federated digital-twin architecture for damage identification and adaptive sensing in sustainable self-sensing cementitious infrastructure. The framework is developed and evaluated entirely in software on a physics-based synthetic testbed. At its present maturity, it is therefore a digital-twin precursor rather than an operational digital twin: it has no calibrated physical counterpart and no live, two-way data coupling, and no experimental validation is claimed. A transparent, physics-based signal generator produces fractional-change-in-resistance signals for twelve virtual CNT/biochar-functionalized LC3 and geopolymer specimens. Each passes through four progressive damage stages interleaved with wet–dry and freeze–thaw conditioning. The framework integrates a CNN-LSTM damage classifier, unsupervised domain adaptation, federated learning, reinforcement-learning-based active sensing, and quantum-inspired aggregation optimization. On three unseen virtual specimens (654 evaluation windows), the CNN-LSTM achieved 70.3% four-stage accuracy (95% Wilson confidence interval 66.7–73.7%) and a macro-F1 score of 0.650, with per-specimen accuracy ranging from 63.8% to 77.1%. It reached 85.2% (95% CI 82.3–87.7%) for the damaged-versus-undamaged decision and reduced environment-induced false alarms by 74.7% (95% CI 61.7–83.4%) relative to a calibrated threshold detector. Federated averaging was less accurate and less stable than centralized training; the 5.2 percentage-point gain from quantum-inspired aggregation lies within the resolution of the evaluation set and is not established as a real improvement. The active-sensing controller reduced measurement cost by 98.9% but detected only four of 27 damage-progression events. All sensing data are synthetic, and every interval reported here is recomputed from the evaluation counts already reported rather than obtained from additional experiments. The results therefore establish algorithmic feasibility only and identify the components requiring refinement before experimental validation. Full article

With rapid development of 5G/6G communication and high-power electronic devices, electromagnetic interference (EMI) shielding textiles are urgently required to mitigate electromagnetic pollution. Traditional metallic shielding suffered from heavy weight, poor corrosion resistance, and secondary electromagnetic reflection, while continuous basalt fibers (CBFs) exhibit excellent mechanical strength, lightweightness, thermal/chemical resistance, and electrical insulation, which makes CBFs ideal substrates for EMI devices. Herein, a multifunctional waterborne polyurethane (WPU) sizing agent (coating emulsion) integrated with Mn-Zn spinel ferrite was developed for in situ lubrication on the as-spun CBFs. The composite sizing agents consisted of a WPU matrix, water-soluble epoxy, mineral oil lubricant, CTAB surfactant, KH-570 coupling agent, and micro-sized Mn-Zn ferrites. Characterizations including particle size distribution, thermogravimetric analysis, water contact angle (WCA), water absorption, FTIR, XRD, and SEM were conducted to verify uniform anchoring of ferrites on the CBF surfaces. Increasing ferrite dosages induced slight particle aggregation, elevated surface hydrophobicity (WCA = 42.4° → 99.43°), and reduced water absorption (65% → 35%), which greatly improved the moisture resistance of the CBFs. The X-band EMI shielding tests revealed that the total shielding effectiveness (SET) of modified CBF fabrics increased from 0.11 dB (pristine fiber without ferrite) to 58.57 dB at a loading of 8.0 g/L ferrite. The absorption loss (SEA) dominated the shielding performance over reflection loss (SER). The low-to-moderate contents (1.5–3.0 g/L) of ferrite achieved ultra-high absorption, while higher ferrite loading (5.0–8.0 g/L) intensified the impedance mismatch and enhanced surface reflection. This work establishes a scalable fabrication of absorption-prioritized lightweight CBF shielding, which provides a feasible pathway for flexible EMI shielding textiles. Full article

Current distribution in serial–parallel battery packs is commonly assumed to be uniform in the absence of cell-to-cell variations. However, in practical systems, the electrical topology and finite resistance of current-collecting busbars can introduce significant inhomogeneities even when all cells are identical. In this work, a matrix-based modeling framework is developed to analyze the current and voltage distribution in large battery packs with arbitrary serial–parallel configurations. The results reveal that the resistance of current-supplying busbars plays a dominant role in shaping current distribution, leading to pronounced current imbalance that increases with both resistance and operating C-rate. To quantify this effect, a current non-uniformity factor is introduced and used to define an illustrative criterion for acceptable operation. Based on this metric, together with a maximum-cell-voltage constraint, design maps are constructed to identify operating regions that are acceptable or critical with respect to current overload and localized overvoltage as a function of busbar resistance and charging rate. The analysis further demonstrates that topology-induced current inhomogeneity can lead to cell-level voltage divergence and localized overcharge under high-current operation. Such local effects may remain hidden when only the pack voltage or the voltage of a series-connected cell group is monitored, because conventional battery management systems (BMSs) typically do not resolve individual cell currents or local voltage drops within parallel-connected cell groups. The proposed approach enables the derivation of design-oriented constraints linking electrical performance to physical parameters such as busbar resistance and cell spacing. The resulting design maps provide a practical tool for battery pack engineering, enabling the determination of the maximum allowable busbar resistance or operating current to ensure safe, homogeneous pack operation. Full article

Copper and lead contamination in loess areas poses a potential threat to soil environmental quality and sustainable land use, while the low permeability, high clay content, and strong buffering capacity of loess often limit the efficiency of conventional electrokinetic (EK) remediation. In this study, a modified activated carbon–carbon fiber (MAC–CF) composite reactive barrier was introduced into an EK remediation system to enhance the soil-phase depletion of Cu and Pb from contaminated loess. The effects of ordinary activated carbon (AC), MAC, CF, and different MAC–CF mixing ratios on current, cumulative electroosmotic flow (EOF), soil pH, electrical conductivity (EC), and potentially toxic metal (PTM) removal were systematically investigated. The conventional AC barrier increased system resistance and inhibited current transmission and EOF. The MAC barrier exhibited enhanced OH⁻ adsorption and buffering capacity, decreasing the cathode-adjacent pH from approximately 9.8 to 8.8. CF incorporation improved barrier conductivity, increasing the peak current from 1.6 A for MAC (100%) to 4.0 A for MAC (25%) + CF (75%), while cumulative EOF increased from approximately 380 to 950 mL. The MAC (25%) + CF(75%) barrier provided the best balance between conductivity enhancement and cathodic alkalization regulation. Sectional Cu removal reached approximately 90% near the anode, whereas Pb removal ranged from approximately 18% to 29%, with a section-weighted mean of about 24.8%. The corresponding residual Pb concentrations (approximately 355–410 mg kg⁻¹) indicate that the system is more effective for Cu and would require additional treatment to meet a conservative agricultural-soil target for Pb. The results support complementary functions of CF in maintaining conductive pathways and MAC in regulating cathodic alkalization. Because Cu and Pb in the spent barrier and electrolyte chambers were not quantified, the proposed precipitation-suppression and migration mechanisms are interpreted from the combined electrochemical, pH, EC, adsorption, and soil-residual evidence rather than from a complete metal mass balance. Full article

The negative differential resistance (NDR) effect provides nonlinear control over ionic current and has important potential in ion sensing and information storage. A multiphys-ics numerical model is established using COMSOL Multiphysics 6.3, coupling the Poisson−Nernst−Planck and Navier−Stokes equations to investigate the effects of solution concentration gradient, pore length, pore diameter, and surface charge density on NDR effect. The results indicate that the NDR effect occurs only in the negative voltage range, where concentration gradient diffusion competes with electric field driven migration. The characteristic voltage window stabilizes between −0.2 V and −0.5 V, and the total current reaches a local extremum near −0.2 V. Electromigration dominates in this range and sup-presses Cl⁻ ion diffusion, while K⁺ transport is less affected, resulting in decreased total ionic current. Under baseline conditions, the total current decreases by 26.19%, from −0.42 nA to −0.31 nA. Increasing the concentration gradient, shortening the pore length, enlarging the pore diameter, and reducing the surface charge density enhance local vortices or maintain Cl⁻ diffusion pathways, thereby strengthening NDR characteristics. This study reveals the regulation mechanisms of NDR effect by solution conditions, macropore structures, and surface properties, providing theoretical guidance for tunable ionic current devices. Full article

Background: Cerebral blood flow (CBF) is essential for maintaining cerebral metabolism in extremely preterm infants; however, no universally accepted reference standard exists for CBF velocity (CBFV). This study aimed to establish physiological reference patterns of middle cerebral artery CBFV under strictly defined physiological stability using multimodal monitoring. Methods: This post-hoc analysis included extremely preterm infants (gestational age ≤ 28⁺⁶ weeks or birthweight 500–1000 g) from a prospective cohort study. Serial Doppler ultrasonography of the middle cerebral artery was performed along with near-infrared spectroscopy and electrical cardiometry. Normal CBFV datasets were defined based on systemic stability, adequate cardiac output (>150 mL/kg/min), normal regional cerebral oxygen saturation (65–85%), and the absence of major comorbidities. Associations between Doppler parameters and postmenstrual age (PMA) and concurrent weight were analyzed using generalized estimating equations. Results: Forty infants contributed 194 normal CBFV datasets. Physiological reference ranges for peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), resistance index (RI), and pulsatility index (PI) were established across PMA and concurrent weight strata. Both PSV and MV were associated with PMA and concurrent weight (p < 0.01), whereas EDV, RI, and PI were not. Mean blood pressure was not significantly associated with CBFV parameters. Conclusions: PSV and MV were maturation-dependent cerebral perfusion markers. Multimodally defined physiological stability provides a robust framework for establishing clinically relevant reference values for middle cerebral artery CBFV in extremely preterm infants. Full article

Circuit carriers perform various functions within electrical systems and products. This includes being the assembly platform for various components. To mount these components, soldering processes are predominantly used because of economic and technical benefits compared to other assembly technologies. Therefore, novel circuit carrier technologies should be compatible with soldering processes to compete with the state of the art. One of these innovative circuit carrier technologies is based on anodized aluminum substrates, which are characterized by their low cost and low thermal resistance. In this article, circuit carriers made of anodized aluminum with two different oxide morphologies being investigated. In addition, three different metallization processes were compared with regard to their suitability for a reflow soldering process for the assembly of surface mount devices (SMDs). In order to evaluate the assemblies, the force required to shear off the SMDs was measured before and after a cyclic thermal shock test (TST). One of the three investigated metallization processes yielded circuit carriers based on anodic aluminum oxide that enabled reflow soldering of the given SMD components. It was determined that both, the layer morphology and the metallization process, had an influence on the measured shear forces before and after TST. Full article

Global plastic waste generation and excessive sand extraction are major environmental challenges, but replacing fine aggregate with plastic waste often degrades concrete performance. This work characterizes concrete incorporating recycled HDPE and PET fine aggregates at a 10% volumetric replacement level, with and without polymer-specific surface treatment, across fresh, mechanical, and durability properties. Untreated plastic aggregate generally lowered mechanical performance due to low polymer stiffness, weak plastic–paste bonding, and greater interfacial void formation. Surface treatment partially offsets these effects by strengthening the plastic–paste bond. H₂O₂-treated HDPE granules recovered the 28-day elastic modulus to within 3% of the control while also improving compressive strength, ultrasonic pulse velocity, and freeze–thaw resistance. H₂O₂-treated HDPE chips showed the highest electrical resistivity and the lowest permeable void content. NaOH-treated PET chips gave the lowest chloride penetrability and the greatest drying shrinkage reduction, approximately 25% relative to the control, though NaOH produced no resistivity gain for PET-C. Freeze–thaw durability factor increased with surface treatment for HDPE-G and PET-C, with HDPE-G-T exhibiting the highest durability factor among the recycled plastic mixtures at 94.20%. These results show that surface-treated recycled HDPE and PET fine aggregate can be incorporated at 10% replacement while maintaining acceptable mechanical and durability performance, supporting recycled plastics as a viable partial fine-aggregate replacement. Full article

An integrated model is presented to estimate the energy consumption of a Formula SAE–type electric vehicle by combining MATLAB/Simulink simulations with real operational data from the Cotopaxi kart circuit. The implemented subsystem incorporates vehicle dynamics, speed, and grade profiles, and it enables the calculation of tractive energy across different competition scenarios. The L3 cycle (maximum speed 90.91 km/h, distance 16.67 km) proved the most demanding, with a tractive energy consumption of 1389.10 Wh, mechanical losses of 630.89 Wh, and a useful net energy of 758.21 Wh. Rolling resistance and inertia accounted for 21.33% and 56.29% of the consumption, respectively, highlighting the influence of acceleration/deceleration dynamics. All cycles were dominated by active phases, with 0% stops and cruising time < 0.21%, validating the model for high-demand conditions. The technical feasibility of second-life Lithium Iron Phosphate (LFP) cells for the battery pack was also confirmed: a 30s2p configuration using 100 Ah cells meets the peak energy demand of 18.30 kWh while maintaining adequate operational margin and a safe discharge C-rate. Structural simulation in ANSYS enabled optimization of mass and stiffness, reducing overall energy demand. This multidisciplinary approach provides a quantitative basis for battery sizing and energy management strategies in competitive electric vehicle applications. Full article

Concrete is the most used construction material, but its long-term performance depends on durability. Although fly ash has been used as a supplementary cementitious material, the effects of its mechanical activation on the concrete durability require further investigation. This study evaluated the influence of replacing 30% of cement with natural Class F fly ash (NFA) and ground fly ash (GFA) in concrete with a water-to-binder ratio (w/b) of 0.62, using a mixture without fly ash (WFA) as reference. Mechanical activation was performed by milling the fly ash, followed by characterization through particle size analysis and X-ray diffraction. Concrete durability was assessed using electrical resistivity, ultrasonic pulse velocity (UPV), water absorption, porosity, rapid chloride permeability (RCPT), carbonation resistance, and compressive strength tests. Mechanical milling reduced and transformed the ash morphology from spherical to amorphous, while quartz and mullite remained the main crystalline phases. Compared with CNFA, CGFA exhibited up to 101% higher electrical resistivity, 39.6% greater resistance to chloride penetration, 10.8% improved carbonation resistance, 0.4% lower water absorption, and a 5.38% reduction in porosity, although compressive strength decreased by more than 20%. These results demonstrate that mechanically activated fly ash is a viable alternative for enhancing the concrete durability performance exposed to aggressive environments. Full article

To address trench-bottom electric-field concentration and the limited BV–R_on,sp trade-off of the conventional shielded-gate trench MOSFET (Conventional SGT), a floating-P-island-assisted silicon SGT MOSFET is proposed. Sentaurus TCAD is used to investigate the effects of increasing the number of floating P-islands from 0 to 3 on BV, R_on,sp, FOM, and electric-field distribution. Within this range, the three-floating-P-island device (3FPI-SGT) provides a favorable BV–R_on,sp trade-off; its drift-region doping matching, dynamic characteristics, and parameter sensitivity are further analyzed. Local depletion around multiple vertically discrete P-islands generates secondary electric-field peaks that share the potential drop with the main trench-bottom peak, reducing field crowding and improving voltage utilization of the drift region. After optimization, the maximum BV and FOM reach 177.7 V and 11.48 MW·cm⁻², respectively. At an identical R_on,sp of 2.62 mΩ·cm², BV increases by 54.6%. At V_DS = 80 V, C_oss and C_rss decrease by approximately 12.8% and 12.5%, while total switching energy increases by only approximately 2.5%. A clear BV advantage is retained under ±20% single-factor deviations in key P-island parameters. Thus, the proposed structure significantly improves the silicon SGT MOSFET BV–R_on,sp trade-off with a limited dynamic-performance penalty. Full article

The harsh sandstorm and the strong electric fields generated by operating transmission lines in desert regions can readily lead to performance degradation and shortened service life of high-temperature vulcanized (HTV) silicone rubber (SR) composite insulators. To screen HTV silicone rubber materials suitable for desert applications, this study conducted aging tests under windblown sand erosion, corona aging, and their combined synergistic effect on three HTV silicone rubber materials. By comparing the evolution of surface morphology and chemical structure under single-factor and combined aging conditions, the acceleration mechanism of erosion on corona aging was analyzed. Further comparison of the performance degradation of the three materials after identical aging durations revealed that the higher the hardness of HTV silicone rubber, the stronger its resistance to erosion, and it retains superior corona aging resistance after erosion. Under combined erosion and corona aging, the high-hardness S3 HTV silicone rubber maintained an intact surface micro-morphology and molecular chain structure, with a smaller reduction in elongation at break, sustained high volume and surface resistivity, and no noticeable deterioration in dielectric properties. A comprehensive evaluation demonstrates that the high-hardness S3 silicone rubber exhibits superior environmental adaptability in desert regions. Full article

Depression is often associated with functional disturbances in the visual system. However, the fundamental features underlying these visual system aberrations in depression remain to be fully elucidated. In particular, in the first stage of visual processing, how different retinal output neuron types change their intrinsic properties and output features in response to specific light stimulation remains unclear. Here, by adopting a mouse model of depression induced by chronic unpredictable stress (CUS), we found that depression is associated with reduced blood perfusion in the retinal inner plexiform layer (IPL). The hypoperfusion in the IPL is paralleled by a remarkable reduction of retinal ganglion cell (RGC) density, with more cell loss in ipRGCs than in the general RGCs. The surviving RGCs—particularly, ipRGCs—changed their intrinsic electrical properties, exhibiting decreased membrane input resistance, more depolarized resting membrane potential, and altered spiking properties. Additionally, these cells showed stimulus-size-dependent increases in light-evoked responses. Together, our findings demonstrate that depression is associated with the retinal IPL hypoperfusion and RGC impairments (particularly ipRGCs) and suggest retinal layer- and RGC-type-specific susceptibilities, furthering our understanding of retinal pathophysiology in depression. Full article