Search Results (297)

Background/Objectives: Implant-associated infections are challenging conditions in orthopedic surgery. This experimental study aimed to evaluate phage localization within infected tissues following different routes of administration. Methods: An implant-related infection model was created using methicillin-resistant Staphylococcus aureus (MRSA) in twenty-four rats. Subjects were randomly divided into four groups depending on the bacteriophage administration route. Three rats were designated as the control group. Phage suspension was applied intraperitoneally, intravenously, orally and locally at 0.1 mL/day of 1 × 10⁸ PFU/mL suspension for three consecutive days. In the control group, intravenous, intraperitoneal and oral phage suspensions were administered separately at the same dose for 3 days. After completion of the experiment, tibia samples were taken in the experimental group. Additionally, liver, kidney, stomach, brain, heart muscle and striated muscle tissue samples were taken from the three subjects in the control group. Results: In the control group, unconfirmed phage-like structures were incidentally observed in some mitochondria of renal proximal tubular epithelial cells on transmission electron microscopy. In the experimental group, there was a strong positive linear relationship between the total number of bacteria and the number of bacteriophage clusters, independent of the groups. Conclusions: Bacteriophage clusters were detected in infected tibial tissues after all administration routes, suggesting phage localization at the infection site. Unexpected phage-like clusters were observed within mitochondria of proximal tubular epithelial cells in the control animals. This finding should be regarded as an unconfirmed incidental finding requiring further validation. Full article

The discharge behavior of granular materials from double-orifice silos is strongly affected by the inter-orifice spacing, yet the mechanical role of the inter-orifice region remains unclear. In this study, discrete element method (DEM) simulations are combined with experiments to investigate the formation, stability, and collapse of an inter-orifice quasi-solid region and its impact on the discharge rate. The results show that increasing the inter-orifice spacing progressively weakens shear transmission between adjacent outlets, promoting the development of a low-velocity, load-bearing quasi-solid region. Based on μ(I) rheology and a nonlocal granular fluidity framework, the quasi-solid region is shown to be controlled by local shear activation rather than by geometric separation alone. Once the inter-orifice quasi-solid region is formed, this region restricts the spatial extension of shear bands near the outlets, leading to a reduction in the effective shear area and a corresponding decrease in the discharge rate. A critical inter-orifice spacing is identified, beyond which the two outlets discharge independently. These findings provide a mechanistic understanding of flow-rate regulation in multi-orifice silos, offering guidance for the design of granular discharge systems. Full article

Early-life microbial community assembly is important for gastrointestinal development, immune maturation, and feed utilization in young ruminants, but the maternal reservoirs associated with neonatal lamb gut microbial profiles remain insufficiently defined. This exploratory study characterized bacterial and archaeal communities in maternal vaginal secretions, amniotic fluid, and colostrum, together with rectal feces from Hu lambs at birth and at 5 days of age, using 16S rRNA gene amplicon sequencing in six matched ewe–lamb pairs. Alpha-diversity differences were evaluated using the Kruskal–Wallis test followed by pairwise Wilcoxon rank-sum tests where appropriate, beta-diversity was assessed by principal coordinate analysis based on Bray–Curtis distance, and discriminatory taxa were identified using LEfSe; statistical significance was defined as p < 0.05. Microbial community structure differed among sample types. Feces collected at birth showed low bacterial richness and a distinct community profile, whereas feces from 5-day-old lambs displayed higher bacterial richness and a more complex taxonomic composition. Shared-ASV and LEfSe analyses suggested that vaginal-associated taxa were more closely associated with the initial fecal microbiota at birth, while colostrum-associated taxa were more evident in day-5 feces. Archaeal communities showed weaker separation than bacterial communities, but methanogenic lineages became more distinguishable by day 5. These findings suggest that early gut microbial assembly in Hu lambs is associated with multiple maternal reservoirs and rapid postnatal ecological selection. However, due to the limited sample size, short observation period, lack of formal source-tracking analysis, and absence of low-biomass negative controls, the results should be interpreted cautiously as preliminary associations rather than definitive evidence of vertical transmission. Full article

The application of silk sericin as a polymeric biomaterial has recently gained interest, although its film was found to be fragile, exhibiting brittleness when subjected to relatively slight stress, and it also displayed higher water solubility. This study focused on the enhanced physico-mechanical properties of the three films obtained by the crosslinking of sericin protein from three silkworm cocoons with poly (vinyl alcohol) (PVA) to reduce phase separation and solubilization of the films by promoting miscibility between sericin and PVA. The findings demonstrated how crosslinking with glutaraldehyde enhanced thermal stability and tensile strength and controlled the solubility of the three sericin–PVA films. The sericin from G. postica, G. rufobrunnea, and Argema mimosae is composed of serine, aspartic acid, and glutamic acid, which make up 80% of the total polar amino acids. X-ray diffraction (XRD) patterns showed that sericin–PVA films have semicrystalline features, representing amorphous and crystalline regions. The XRD results also indicated that the Saturniidae sericin–PVA film (Sat-SPF), Gonometa postica sericin–PVA film (GP-SPF), and Gonometa rufobrunnea sericin–PVA film (GR-SPF) have crystallinity percentages of 66.4%, 55.9%, and 17.7%, respectively. The moisture vapor transmission rate (MVTR) values observed in this study ranged from 991.2 to 5160 g/m²/24 h, indicating that these films can effectively regulate moisture levels in wounds. The swelling capacity of the three sericin–PVA composite films depends on the crosslinking density of their structures and was also found to be sensitive to the pH of the aqueous media, demonstrating their hydrophilic nature and potential use in drug delivery systems. The water vapor permeability of sericin–PVA films increased with higher environmental relative humidity (RH) and moisture content within the films. The elongation at break for GP-SPF (107.2% ± 3.1) and Sat-SPF (73.0% ± 4.1) was significantly higher than in GR-SPF (29.3% ± 2.3). However, their tensile strength and elastic modulus were lower than those of GR-SPF. These results show that the number of polar groups (amino and hydroxyl groups) from both sericin and PVA influences all the properties of the sericin–PVA composite films. The three sericin–PVA solutions were found to have antibacterial efficacy against three Gram-positive and one Gram-negative bacteria over 24 h. Scanning electron microscopy (SEM) images revealed a rough surface with a granular network pattern, which supports the potential use of sericin–PVA films for cell adhesion and proliferation, which are essential for biomedical wound dressing applications. Full article

Accurate and reliable groundwater-level monitoring in deep observation wells remains difficult for conventional non-contact ultrasonic systems because narrow tubular geometries intensify multipath reflections, signal attenuation, and echo ambiguity. This study proposes a dual-signal direct time-of-flight (ToF) method that combines radiofrequency (RF) synchronization with one-way airborne ultrasonic propagation to a floating receiver located at the groundwater surface. In the proposed architecture, the RF signal provides a near-instantaneous time reference, whereas the ultrasonic signal defines the propagation delay, thereby eliminating dependence on echo-based ranging. The system integrates a wellhead surface unit for synchronized transmission and control, a floating unit for ToF acquisition and embedded processing, and an optional reference channel for in situ estimation of the effective sound speed. A duty-cycled power architecture is used to support low-power long-term deployment, while a multi-shot acquisition strategy with a median-like estimator improves robustness against startup transients, timing jitters, and false detections. Field validation was conducted over a 12-month period under actual groundwater-monitoring conditions, during which the groundwater depth varied between 14 m and 30 m below the wellhead datum. Within this field-validation interval, the proposed system achieved a mean absolute error of 0.048 m, a maximum absolute error of 0.050 m, and an overall valid detection rate of 99.4% over 358 valid cycles out of 360 scheduled cycles. In addition, a separate range-dependent confined-tubular propagation test was conducted to evaluate the extended detection capability of the RF-synchronized one-way ultrasonic ToF architecture. This test demonstrated stable acoustic-link ToF detection up to 300 m inside the tested 170 mm confined plastic pipeline. Therefore, the 300 m result should be interpreted as a range-dependent valid-detection result rather than as a 12-month groundwater-depth validation over the full 300 m interval. These results demonstrate that the proposed direct-ToF method provides an RF-synchronized one-way ultrasonic ToF framework with a floating receiver for groundwater-level monitoring in deep observation wells, while remaining compatible with low-power and IoT-based environmental monitoring systems. Full article

With the integrated development of high-speed railways and urban underground rail transit, large high-speed railway station buildings are often seamlessly connected or even co-constructed with subway structures, forming a complex structural system that integrates high-speed rail, subway, and station buildings. To investigate the dynamic performance of such “ integrated station-bridge” station buildings constructed with subways, this paper takes Yichang North Station as an engineering case study and examines its vertical dynamic characteristics under multi-source train-induced loads. The station adopts a structural configuration where the station tracks are fully integrated with the station building, while the main lines are separated from it. To accurately simulate the entire process of train operation, this study established a refined “train-track-station” spatially coupled dynamics model that incorporates high-speed and subway trains, tracks, and the station structure. Based on this model, various operational scenarios were systematically analyzed, including high-speed trains passing at different speeds, parallel operation of multiple train lines, and combined operation of high-speed and subway trains. The results demonstrate that, when single or multiple high-speed train lines pass through the station at the design entry speed of 80 km/h, the vertical vibration acceleration of the elevated waiting level meets human comfort standards. The train-induced vibration response is transmitted and superimposed along the “column–beam–slab” path, resulting in localized acceleration peaks at the mid-span regions of beams and slabs directly above the tracks. Second, the impact of subway train operation alone on the vibration of the elevated level is significantly weaker than that of high-speed trains. Furthermore, under combined high-speed and subway train operations, the additional vibration contribution from subway trains shows a decreasing trend as the number of simultaneously operating high-speed train lines increases. The findings of this study validate the effectiveness of the structural design of Yichang North Station in terms of train operational safety and passenger waiting comfort. The revealed patterns of multi-source vibration transmission and superposition can provide important theoretical and numerical references for the dynamic optimization design and vibration control of similar integrated transportation hub structures. Full article

On-orbit micro-vibration has emerged as a critical constraint impairing the imaging performance and ultra-high pointing accuracy of space optical payloads. Most existing investigations separately concentrate on disturbance modeling, vibration isolation design, or line-of-sight (LOS) stabilization, leaving the full-link integrated dynamic modeling and analysis severely insufficient. To address this gap, this paper proposes an integrated dynamic modeling methodology for spacecraft equipped with optical payloads, which synergizes disturbance identification, finite element modeling, model order reduction, hybrid active–passive vibration isolation mechanism control, and fast steering mirror (FSM) regulation. The experimental and simulation results demonstrate that the root mean square (RMS) acceleration induced by flywheels and pumps at the mounting interface of the vibration isolation mechanism approximates 4.50 mg. Specifically, the passive vibration isolation scheme attains an attenuation of −16 dB, while the hybrid active–passive strategy achieves a remarkable −30 dB attenuation. Moreover, flywheels generate lower acceleration amplitude but more severe LOS jitter, owing to their time-varying disturbance characteristics and dispersed frequency energy distribution. Additionally, a full-spacecraft micro-vibration ground test incorporating horizontal gravity unloading via suspension is implemented to validate the model. The model-calculated acceleration and pointing angle exhibit excellent consistency with the experimental data, with the relative acceleration error below 7% and the angular error less than 9%. The proposed integrated dynamic model enables accurate prediction of micro-vibration transmission and suppression performance, laying a dependable theoretical foundation for design optimization of high-precision spacecraft systems. Full article

Index-modulated orthogonal frequency division multiplexing (OFDM-IM) has been recognized as a promising multicarrier transmission scheme due to its flexibility and favorable bit error rate (BER) performance. However, for future wireless communication systems requiring high reliability, high spectral efficiency, and low complexity, existing OFDM-IM schemes still face challenges in simultaneously improving spectral efficiency, maintaining diversity gain, and controlling detection complexity at the receiver. To address these issues, this paper proposes a joint-mode and repeated-index modulation-based coordinate interleaved OFDM scheme (MRIM-CI-OFDM). Building upon the shared subcarrier activation pattern (SAP) and coordinate interleaving structure, the proposed scheme introduces cross-cluster mode-pair indexing, enabling information bits to be jointly carried by the SAP domain, mode domain, and constellation symbol domain. This design enhances spectral efficiency while preserving the diversity advantages of coordinate interleaving. Furthermore, a rotated multi-mode constellation construction method based on inter-constellation minimum product distance is developed to improve mode separability. By exploiting the equivalent real-valued orthogonal structure introduced by coordinate interleaving, low-complexity maximum likelihood (ML) and three-stage Max-Log detectors are constructed. Simulation results demonstrate that the proposed low-complexity detectors achieve near-ML detection performance. Additionally, at a spectral efficiency of 1.25 bps/Hz, MRIM-CI-OFDM achieves approximately 3 dB SNR gain over the coordinate-interleaved/repeated-index benchmarks and more than 5 dB gain over conventional OFDM-IM. Full article

This study examines how urban transportation systems influence the spatial spread of infectious diseases by developing a modified Susceptible–Exposed–Infected–Recovered (SEIR) model with explicit intercity travel dynamics. The model distinguishes between two mobility mechanisms: travel volume, represented by the departure rate g, and travel speed, represented by the arrival rate $\alpha$. Using the next-generation matrix (NGM) approach, we derive the basic reproduction number $R_0$ and analyse how within-city and transit-phase transmission contribute to epidemic spread. The results show that travel volume and travel speed affect mobility-driven transmission through distinct mechanisms. Increasing g increases the number of travelers entering the transit system and therefore amplifies the aggregate number of transit-mediated infections, although the per-capita transit reproduction expression is governed primarily by $\alpha$ and ${\beta }_d^T$ under the reduced next generation matrix formulation formulation. By contrast, increasing $\alpha$ shortens the time spent in transit, reduces the exposure window during travel, and lowers the per-capita contribution of transit-based infection to $R_0$. Numerical simulations illustrate these effects and support the conclusion that reducing travel volume can mitigate intercity epidemic spread by decreasing the number of potentially exposed travelers. Comparative case studies for Brazil, New Zealand, China, and Algeria are used to evaluate the model under different epidemiological settings and socioeconomic contexts. These socioeconomic indicators are treated as contextual background rather than as direct inputs to the mathematical model. The qualitative predictions of the ordinary differential equation (ODE) model are further cross-validated using an agent-based simulation implemented in NetLogo. Overall, the study shows that separating travel volume from travel speed provides a more precise understanding of mobility-driven disease transmission and can support the design of targeted travel-related control measures. Full article

High-precision beam pointing control is essential for achieving reliable data transmission in space laser communication systems, requiring effective suppression of multi-frequency disturbance-induced tracking residuals. To address this issue, a synergistic model predictive control and disturbance observer (DOB-MPC) architecture is developed. The proposed hierarchical control framework is constructed based on gimbal servo dynamics and implemented through the following steps. A frequency-decoupled disturbance observer (DOB) is employed to estimate multi-frequency disturbances using spectral separation principles, while a model predictive controller (MPC) enhances steady-state accuracy by compensating for time-delay effects through trajectory optimization. Crucially, the disturbance estimates are incorporated into the MPC’s prediction horizon via receding-horizon optimization, establishing a cooperative control mechanism. Simulation results demonstrate improvements of greater than 25% in dynamic response and over 80% in residual error reduction compared to conventional methods. Experimental results further validate the efficacy of the proposed architecture for space laser tracking systems. Full article

To address the issue that substations are prone to failures during flood disasters, which further cause large-scale and prolonged power outages, a coordinated optimal allocation strategy of flood control resources is proposed to enhance power grid resilience. Firstly, the failure and network features for substations are constructed considering the uncertainty of flood depth. Subsequently, a representative set of failure scenarios for transmission and distribution (T&D) substations is generated based on feature selection. Secondly, accounting for the coupling relationship between the availability status of T&D substations and the operation strategies of active distribution networks, a transmission-distribution coordinated stochastic optimization model is established to optimize the allocation of flood control resources. The objective is to minimize the system’s expected comprehensive costs incurred by substation structural damage and load shedding constrained by the pre-disaster substation protection constraints and the operation constraints in T&D networks during flood disasters. Finally, numerical case studies based on the improved T24D40 system are conducted. The results demonstrate that the feature-selection-based scenario generation method enables the critical substations with high failure rates and network importance to gain higher protection priority. More importantly, compared with separate decision-making and with limited coordinated decision-making for T&D substation protection schemes, the proposed model, which could effectively maximize the utilization efficiency of flood control resources, reduces the system’s expected comprehensive costs by 32.1% and 8.9%, respectively. Full article

Background: Cystic echinococcosis (CE) is a chronic zoonotic parasitic disease with a significant impact on public health in endemic regions. The liver is the most frequently affected organ, and ultrasound-based surveys are considered a reliable tool for detecting asymptomatic infections. As population-based data specifically addressing hepatic CE prevalence in Türkiye remain limited, we aimed to assess the prevalence of liver cystic echinococcosis in Türkiye using only ultrasound-based surveys. Methods: A systematic review was conducted, in accordance with the PRISMA guidelines, to estimate the prevalence of liver CE in Türkiye based exclusively on ultrasound-based field surveys. Electronic databases (PubMed and Scopus) were searched up to March 2026. Eligible studies included population-based human screening surveys reporting hepatic CE prevalence confirmed via ultrasonography. Data were extracted and descriptively pooled, with subgroup analyses performed according to age group (children vs. adults) and residential setting (urban vs. rural). The protocol was prospectively registered in the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY; registration Number: INPLASY202630029). Only human ultrasound-based screening studies including liver CE data were accepted; alveolar echinococcosis studies were excluded. Pooled prevalence estimates with 95% confidence intervals (CIs) were calculated using a random-effects model, and between-study heterogeneity was assessed with the I² statistic. Results: We analyzed the data of 23,154 people from 11 different provinces reported in 8 studies. The overall pooled liver CE prevalence was 0.31% (95% CI: 0.14–0.54), while it was 0.12% and 0.43% for urban and rural residents, respectively. Adults had higher prevalence of liver CE than children (0.43% vs. 0.16%). When separated by both living area and age, the prevalence rates were as follows: urban children 0.07%, urban adults 0.21%, rural children 0.29% and rural adults 0.60%. Conclusions: This is the first systematic review evaluating the prevalence of liver CE in Türkiye exclusively from ultrasound-based studies. While the overall prevalence of liver CE was 0.31%, adults living in rural areas presented a nearly two-fold higher rate (0.60%). Ultrasound-based screening provides a practical and effective approach for epidemiological surveillance. Targeted control strategies—including community-based screening, health education, and veterinary interventions—are essential to reduce transmission and disease burden, particularly in high-risk rural populations. Full article

Bilayer scattering films offer a practical route to independently controlling transmission and reflection in transparent optical systems, yet the separate roles of nanoparticle loading and stacking order remain underexplored. In this work, Al₂O₃/poly(methyl methacrylate) bilayer films with four concentration pairs (5/15, 15/5, 5/30, and 9/30 wt%) were fabricated by sequential spin-coating and characterized by wavelength-dependent transmittance, reflectance, integrating-sphere haze decomposition, and optical surface interferometry under both glass-side (G-incident) and scattering-layer-side (SL-incident) illumination. Two independent design parameters govern the optical response: (i) the maximum nanoparticle concentration sets the overall scattering regime, and (ii) the layer stacking order controls the partitioning between parallel transmittance (PT) and diffuse transmittance (DT). Bilayers with a maximum loading of 15 wt% maintained total transmittance (TT) ≈ 99% and moderate haze (25%–40%), while reciprocal 5/15 and 15/5 wt% pairs exhibited a ~15 percentage-point shift in PT despite identical total loading. Incorporation of a 30 wt% layer shifted films into a diffusion-dominant regime (DT > 68%, haze > 70%), and positioning this layer at the incident side under SL illumination suppressed visible reflectance below 1%. These results provide a practical composition–sequence design map for transparent optical coatings in display, privacy, and anti-glare applications. Full article

Vision-based structural health monitoring offers a promising alternative to conventional wired sensing systems; however, its adoption is often limited by high hardware costs and computational constraints at sensing nodes. This study presents the design and laboratory validation of a low-cost vision-based system for displacement and strain monitoring using a centralized processing architecture. The proposed system separates image acquisition from computation, where an ESP32-CAM module serves as a lightweight edge node for grayscale image capture and wireless transmission, while computational tasks including displacement tracking, subpixel localization, scale calibration, and strain estimation are performed on a centralized unit. This enables low-cost deployment at USD 60 per node with low power consumption at 1 W. System performance was evaluated through controlled experiments, including a 24 h zero-drift test and quasi-static displacement tests up to 15 μm. Validation against a Linear Variable Differential Transformer (LVDT) shows close agreement, with an absolute error of 2.63 µε and drift within ±2 μm. The system achieves an effective strain range of ±35,000 με. These results demonstrate the potential of low-cost centralized vision-based systems, demonstrating strong potential for practical deployment in structural health monitoring applications. Full article

One of the challenges in managing mobility in a heterogeneous network domain remains a significant challenge in Software-Defined Networking (SDN). While SDN has effectively facilitated intra-domain mobility, inter-domain mobility has been a major issue, leading to service interruptions, packet loss, and unstable communication sessions. This article presents a new concept in mobility management: a hybrid SDN-LISP network that facilitates inter-domain communication by integrating SDN with the Locator/Identifier Separation Protocol (LISP). The main idea is to introduce a new event-based orchestration model that uses OpenFlow Packet-In messages to provide instantaneous updates to Endpoint Identifiers-to-Routing Locators (EID-to-RLOC) mappings, unlike traditional LISP, which relies on timers for updates. The proposed framework has been implemented and evaluated on a Mininet-WiFi testbed under various mobility conditions. The results obtained from the experimental evaluation reveal that packet loss is reduced by 92.32% when using the proposed framework over the conventional SDN Mobility approach. Although there is a slight increase in jitter overhead due to LISP encapsulation of 0.628 ms, the framework does not compromise Transmission Control Protocol (TCP) session continuity. In addition, the control plane synchronization time is also minimized to 277.5 ms. This reveals that the proposed framework is a stable mobility solution that does not depend on any conventional IP mobility solutions and can be used in future network environments requiring seamless inter-domain connectivity. Full article