Search Results (5,979)

Background and Objectives: The optimal timing of orthodontic intervention in children remains debated, particularly during the mixed dentition phase. Despite potential benefits, variability in clinical decision-making persists. This study explored orthodontists’ perceptions, clinical practices, and clinical decision-making regarding the timing of early orthodontic intervention in Saudi Arabia. Materials and Methods: An interpretive qualitative study was conducted using semi-structured interviews with nineteen licensed orthodontists practicing in Saudi Arabia. Participants were purposively sampled to ensure diversity in clinical experiences and practice settings. Interviews were conducted in English and Arabic, using detailed contemporaneous field notes that were subsequently expanded for analysis. Data were analyzed using thematic analysis following Braun and Clarke’s framework, with iterative coding supported by investigator triangulation, reflexive memoing, and participant validation. Data collection continued until thematic saturation was achieved. Results: Four major themes were identified. Early intervention was widely perceived as beneficial, particularly for functional problems, Class III malocclusions, and crossbites. However, decision-making was highly individualized, with many clinicians adopting a selective approach and deferring treatment in mild cases. Variation in clinical reasoning was observed across individual participant accounts, reflecting clinical judgment and contextual influences. Key barriers included limited parental awareness, financial constraints, and delayed referrals. System-level factors, such as variability in insurance coverage, referral pathways, and the lack of structured early screening programs, were identified as important influences on access to timely care. Conclusions: Early orthodontic intervention should be applied selectively, based on clinical indications and patient-specific factors. The context-specific findings highlight the need for appropriately tailored guidance, improved referral systems, structured early screening, and consideration of clinical, practitioner-related, and healthcare system factors to support consistent, patient-centered orthodontic care. Full article

Delayed post-sowing watering may leave treated wheat (Triticum aestivum) seeds in dry soil for several weeks before germination begins, raising the question of how long the effects of seed-applied biostimulants remain biologically active under these conditions. This study evaluated the persistence of the biological effects of a seed-applied biostimulant, applied alone (BS) or combined with a triticonazole-based fungicide (TBS), after delayed watering of wheat seeds. Seeds were watered immediately after sowing or after 2, 3, 4, or 5 weeks and evaluated in Petri dishes and growth pots. Compared with the untreated control, BS and TBS reduced mean germination time by up to 9.4 h and 8.7 h, respectively (p < 0.05), while also promoting greater seminal root development after prolonged exposure to dry conditions. In the pot experiment, treatments including the biostimulant maintained greater root dry weight at both BBCH 11 and BBCH 12, indicating that a measurable stimulatory response was still observed beyond germination and early seedling establishment. The strongest responses were observed when watering was delayed by 2–3 weeks, remained evident after 4 weeks, and declined after 5 weeks of dry sowing conditions. Under the conditions of this experiment, the results demonstrate that, although the biostimulant supports early root system development after moisture restoration, the magnitude of the treatment response is conditioned by the duration of the pre-germination waiting period. Full article

Background: Streptococcus suis serotype 2 is a major zoonotic pathogen responsible for severe systemic infections in pigs and humans, including septicemia, meningitis, and high mortality outcomes. Cefquinome, a fourth-generation β-lactam antibiotic widely used in veterinary medicine, is commonly applied for the treatment of S. suis infections. However, optimized dosing strategies remain insufficiently defined, particularly under conditions of varying bacterial burden, inoculum size, and reduced susceptibility or resistance phenotypes. These factors may significantly alter pharmacodynamic responses and compromise the predictive value of conventional MIC-based approaches. Objectives: This study aimed to characterize the pharmacokinetics (PK) and pharmacodynamics (PD) of cefquinome against S. suis serotype 2 using an integrated ex vivo serum time-kill experiments and semi-mechanistic PK/PD modeling. A secondary objective was to evaluate optimized dosing regimens across different inoculum levels and susceptibility phenotypes, including a cefquinome-resistant mutant. Methods: Cefquinome pharmacokinetics following intramuscular administration at 2 and 4 mg/kg in piglets were described using a two-compartment model. Dose proportionality, exposure linearity, and clearance parameters were assessed. Ex vivo serum time-kill experiments were conducted using a parental strain and a cefquinome-resistant mutant (M1) under normal-inoculum (NI), high-inoculum (HI), and mutant/resistant (MS) conditions. A semi-mechanistic PK/PD model incorporating logistic bacterial growth, sigmoidal Emax killing, nutrient limitation, and a time-delay function was developed to describe dynamic bacterial responses. Model parameters (k₀, k_max, EC₅₀) were estimated using nonlinear least-squares regression (Scientist v2.0), and simulations were performed by integrating time-varying PK input functions. Results: Cefquinome demonstrated linear pharmacokinetics with dose-proportional increases in Cmax and AUC between 2 and 4 mg/kg, with comparable clearance across doses. Ex vivo studies revealed time-dependent antibacterial activity with a pronounced inoculum effect. Higher bacterial burdens significantly reduced bactericidal efficiency and promoted regrowth during declining drug exposure. No tested concentrations achieved ≥3-log₁₀ killing in HI or MS conditions, whereas the NI group achieved a maximal reduction of 3.5-log₁₀ CFU/mL. MIC values in serum and medium were consistent (0.03, 0.06, and 0.24 µg/mL for NI, HI, and MS, respectively), indicating minimal protein binding influence. The semi-mechanistic model accurately described observed bacterial dynamics (R² > 0.99; MSC > 1.5), capturing delayed drug effects, inoculum-dependent growth suppression, and regrowth phenomena. Growth rates were reduced under serum conditions, reflecting nutrient limitation. Importantly, inoculum size exerted a stronger impact on pharmacodynamic outcomes than resistance phenotype, as reflected by reductions in kmax and increases in EC₅₀ under HI conditions. Although %T>MIC exceeded conventional β-lactam targets (>40%) in most regimens, MIC-based indices poorly correlated with observed dynamic killing responses. Conclusions: Cefquinome exhibited time-dependent antibacterial activity against S. suis serotype 2, strongly modulated by inoculum size and reduced susceptibility. The developed semi-mechanistic PK/PD model provided robust prediction of bacterial time-kill behavior and outperformed MIC-based metrics in guiding dose optimization. Simulation results support 2 mg/kg every 24 h for normal infections and 2 mg/kg every 12 h for high-inoculum or less susceptible infections, emphasizing the value of model-informed dosing strategies for optimizing β-lactam therapy. Full article

Construction equipment monitoring has shifted from manual logbooks and early telematics toward intelligent digital systems, driven by the need to reduce delays in obtaining equipment data and improve decision-making on construction sites. This study examines research on construction equipment monitoring and tracking published between 2000 and 2026 to identify the evolution, major themes, and emerging directions in the field. A scientometric and bibliometric analysis was conducted on 1093 bibliographic records retrieved from Scopus and Web of Science on 20 May 2026. The annual publication trend was evaluated through 2025, the last complete publication year, while records indexed in 2026 were retained for the remaining corpus-level analyses. The datasets were preprocessed and analyzed using Bibliometrix, VOSviewer, and CiteSpace to examine publication trends, keyword networks, collaboration patterns, citation structures, and research clusters. The keyword network was interpreted through six major thematic clusters, which were synthesized into four broader knowledge streams covering operations and sensing, AI-based perception, safety monitoring, and BIM/digital-twin integration. The results show a substantial increase in the representation of AI- and perception-related research across the later publication periods, reflecting a transition from basic sensor-based approaches toward more intelligent and connected site systems. The study identifies leading contributors and comparatively underdeveloped research priorities, particularly real-time idle-state detection, multimodal data fusion, multi-site validation, and the integration of monitoring outputs with BIM and digital-twin decision-support environments. Full article

The Proportional-Integral-Derivative (PID) controller has been recorded as the most practical, reliable, and easy to implement feedback control system since its invention in the second decade of the twentieth century. Its adequacy has led to its utilization in approximately 90% of all industrial applications. In the last decade, Proportional-Integral-Retarded (PIR) controller has been introduced as a derivative-free controller to avoid the problem of noise amplification by the derivative term present in the PID controller. Instead of employing the error’s derivative in the control law, PIR controller employs an intentional retarded (exponential) term to provide damping for oscillations in systems with time-delay and enhance their stability. This paper develops, analyzes, and assesses the PIR controller for the heat diffusion system. Stability boundary loci are used to define the stability regions of the PIR controller’s parameters. Compared to a published study which applied PID and fuzzy logic to control the heat diffusion system, the developed PIR controller provides higher speed response by reducing the settling time by 77.082% and 74.992% as compared to PID and fuzzy-PID control systems in response to a step input of +18 °C. It also reduces the integral square error by 54.15% in comparison with the PID control system. Finally, the peak deviation in PIR control system response to an +18 °C disturbance is less than that of the PID control system by 0.167 °C. Full article

Background/Objectives: Kidney transplantation is the most effective treatment for pediatric patients with end-stage renal disease (ESRD), offering superior survival rates and quality of life compared to dialysis. However, long-term graft survival remains a complex clinical and surgical challenge. This systematic review aims to evaluate short- and long-term graft outcomes and comprehensively analyze the primary clinical, immunological, and procedural risk factors driving pediatric graft failure. Methods: A comprehensive search was conducted across the PubMed database, yielding 289 initial records. Following duplicate removal and systematic title and abstract screening, 108 full-text articles were evaluated for eligibility. Ultimately, 35 high-quality studies met the full inclusion criteria and were selected for final data synthesis and analysis. Results: Synthesized data revealed high short-term outcomes, with a 1-year graft survival rate of 94.60%. However, survival experienced a steady decline over time, dropping to 59.50% at the 10-year mark. Acute rejection episodes and delayed graft function (DGF) were identified as the primary immunological primary risk factors. Furthermore, specific donor characteristics, early surgical complications (such as vascular thrombosis), post-transplant infections affecting nearly 45% of patients, and adolescent non-adherence to immunosuppressive regimens were heavily associated with accelerated graft failure. Conclusions: While short-term success in pediatric kidney transplantation is highly encouraging, long-term graft longevity requires targeted clinical interventions. Optimizing outcomes necessitates precise, lifelong management strategies specifically focused on mitigating chronic rejection, preventing post-operative infections, and implementing multidisciplinary support systems to enhance patient adherence to immunosuppressive therapy. Full article

This paper studies performance analysis and load frequency control (LFC) for a Takagi–Sugeno (T-S) fuzzy power system equipped with an energy storage unit. A corresponding T-S fuzzy representation of the system is constructed. Subsequently, a new lemma of slack Lyapunov function is constructed, which relaxes the conventional positive-definiteness requirement on the quadratic form, provides additional flexibility in the LMI formulation, and yields less conservative stability conditions. In addition, a genetic-algorithm-based outer search is employed to optimize the scalar parameter $\varrho$, while the associated LMIs are solved using the LMI solver, thereby reducing the conservatism of the stability conditions and enlarging the maximum allowable delay bound. Simulation cases are finally presented to confirm the feasibility and effectiveness of the proposed methods. The proposed method increases the maximum allowable delay bound by $2.6920\%$, $4.0220\%$ and $4.0528\%$ compared with the reference method for the tested controller parameters. Full article

To meet the requirements of differentiated pesticide application between soybean and maize strips in soybean–maize strip intercropping systems, this study developed a strip-specific variable-rate spraying system based on real-time prescription map interpretation and spatiotemporal nozzle matching with delay compensation. A simulated prescription map with predefined application-rate levels was generated using ArcMap and converted into a binary data structure suitable for embedded-controller access. Based on high-precision RTK-BDS positioning information, a local field coordinate transformation model was established and combined with SRAM-based memory preloading to achieve rapid prescription matrix addressing. To reduce boundary misalignment caused by positioning offset, actuator response lag, and hydraulic delay during dynamic field operations, a nozzle spatial position prediction model and a forward delay-compensation control algorithm were developed. Results from the strip-specific variable-rate spraying tests based on the simulated prescription map showed that, under the tested conditions, the mean boundary offset decreased from 0.69 m to 0.29 m after delay compensation. The mean flow-rate control accuracy for both soybean and maize strips exceeded 95% across different application-rate levels, while the coefficients of variation of flow rate were below 6%. These results indicate that, under the tested conditions, the developed system was able to perform real-time prescription map interpretation, target application-rate matching, and strip-specific variable-rate control, demonstrating its technical feasibility for variable-rate spraying in soybean–maize strip intercropping. Full article

A distributed nonfragile controller is developed for stochastic delayed multi-agent systems in which nonlinear terms, plant uncertainties, and gain perturbations are activated randomly. The directed topology is assumed to admit a spanning tree whose root is the leader. Each follower uses relative-state data from both the present and delayed instants; this construction is used to obtain asymptotic stochastic tracking in the presence of state and communication delays. For a constant delay, the analysis produces tractable linear-matrix-inequality tests and the corresponding gain matrices. The construction is then adapted to time-varying delays. The predicted tracking behavior is illustrated by two numerical examples. Full article

Towed hydrophone arrays are widely employed for underwater target detection and direction-of-arrival (DOA) estimation. However, array shape distortion induced by ocean currents, internal waves, and platform maneuvers severely degrades beamforming performance and DOA estimation accuracy. In this paper, a novel Bayesian fusion framework is proposed to achieve robust array shape estimation. Specifically, based on the time-delay estimates derived from the phase differences of line-spectrum components in a pre-processing step, the array geometry is first reconstructed via a piecewise straight-line fitting method. Concurrently, an existing hidden Markov model (HMM)-based method is adopted to estimate the inter-segment deviation angles, in which the smoothness of the array shape is enforced through the state-transition probabilities. The proposed framework then treats these two preliminary estimates as observations from distinct sources and incorporates a smoothness prior within a maximum a posteriori (MAP) formulation that admits a non-iterative closed-form solution to enforce physical continuity constraints on the array geometry. By fusing these complementary estimates, the proposed method simultaneously preserves local sensitivity to fine-scale bends and maintains global consistency of the array shape. Both simulation and lake-trial experiments validate the effectiveness of the proposed method, reducing the array shape estimation error by more than 30% relative to representative existing methods. Moreover, by relying solely on the received acoustic data, the method lowers the dependence on auxiliary sensors and the associated system cost. Full article

Urban mobility systems generate large volumes of heterogeneous geospatial data that differ in temporal resolution, spatial coverage, update frequency, and semantic structure, making integrated near-real-time analysis difficult. This paper presents a geospatial big-data framework for integrating and analyzing multimodal urban mobility data from the Norwegian transport ecosystem, including public transport, micromobility, road infrastructure, weather sensing, and civil aviation. The framework is implemented as a modular pipeline for data ingestion, source-specific normalization, temporal alignment, and analytical processing, enabling minute-level comparison across heterogeneous operational feeds. The proposed approach preserves source-level semantics while supporting unified spatiotemporal analysis across transport modes with different operational characteristics. The framework is evaluated through analytical scenarios focused on peak and off-peak mobility dynamics, weather-related multimodal variability, and spatial autocorrelation of public transport activity and delay across four analysis windows and six Norwegian cities. The results show that mobility–weather relationships vary across transport modes and temporal windows, particularly in public transport activity, cycling behavior, and delay patterns, and that spatial clustering of public transport activity and delay is itself city- and window-dependent, with some cities showing strong, stable clustering and others showing none. The findings indicate that multimodal urban mobility should be interpreted as a context-dependent and interconnected spatiotemporal system rather than through isolated modal indicators. The study demonstrates how geospatial big-data integration can support near-real-time urban mobility monitoring and operational analytics in smart-city environments. Full article

Testbed configurations and interfacing methods for real-time digital simulation of cyber-physical power systems (CPPS) remain complex and fragmented across the literature, limiting the clarity with which researchers can compare tools, reproduce testbeds, and select suitable platforms for communication-aware control and cyber security studies. This paper addresses this issue by first comparing the latest works with particular focus on the method of interfacing and configuration architecture, and second, by showcasing two representative testbeds, used for analysing the impact of cyber events on distribution system and microgrid operation. The first testbed interfaces HYPERSIM (OPAL-RT Technologies) with MATLAB (version R2025a) using Modbus over TCP/IP for data exchange. This testbed configuration is capable of capturing the impacts of communication delays on Volt-VAR control in a modified IEEE 13-node test feeder. The second testbed uses two real-time power simulators, OPAL-RT and Typhoon HIL, both interfaced with the discrete-event simulator (DES) EXata Network Modelling (by Keysight Technologies) through modular Python-based scripts. This interfacing effectively enables the simulation of cyber attacks in microgrids. These testbeds show how recent advances in real-time simulation are enabling more practical cross-domain analysis of communication effects, control performance, and cyber vulnerabilities, while informing the design of more capable and future-ready CPPS simulation environments. Full article

Background/Objectives: This study aimed to compare the incidence, extent, and time to diagnosis of osteonecrosis of the femoral head (ONFH) between Femoral Neck System (FNS) and multiple cannulated screw (CS) fixation in patients with femoral neck fractures (FNFs) at a minimum follow-up of 24 months, as well as to identify factors associated with ONFH after FNS fixation. Methods: A retrospective cohort study was conducted at a single university hospital involving patients aged ≥18 years with isolated FNFs treated by closed reduction and internal fixation using either FNS or multiple CS. Reduction quality, fracture union, incidence and extent of ONFH (measured by Kerboul angle), and revision surgery due to ONFH or other causes were assessed as outcome measures. Logistic regression analyses were conducted to identify factors associated with ONFH after FNS fixation. Results: Eighty-seven patients were included, comprising 48 in the FNS group and 39 in the CS group. No significant differences were found between the groups in reduction quality, union rate, or time to union (p > 0.05 for all). The incidence of ONFH did not differ significantly between the FNS and CS groups (p = 0.314). However, the FNS group showed a significantly greater extent of ONFH (p = 0.031) and longer mean time to ONFH diagnosis (p = 0.001). No significant differences were observed in revision surgery rates due to ONFH (p = 1.000) or other causes (p = 0.624). Multivariate analysis identified fracture displacement (Garden classification stages III and IV) and poor reduction quality (“Broken S” by Lowell’s criteria) as significant predictors of ONFH after FNS fixation. Conclusions: ONFH following FNS fixation tended to exhibit a larger necrotic area and a delayed radiographic onset compared to CS fixation; however, the overall incidence and revision rates were comparable between implants. These differences may be due to initial fracture displacement and baseline severity, rather than the FNS implant itself. In the FNS group, the mean time to radiographic diagnosis of ONFH was 13.1 months, and initial fracture displacement and reduction quality were identified as risk factors for the development of ONFH following FNS fixation. Therefore, long-term and vigilant follow-up is essential after FNS fixation, particularly in patients with displaced fractures. Achieving optimal reduction quality and anatomical femoral neck alignment remains paramount to mitigating the risk of ONFH after FNS fixation. Full article

To overcome the limitations of existing three-degree-of-freedom milling stability models in representing axial cutting conditions, this study develops a stability prediction framework that accounts for both axial segmentation and the axial contact angle. A three-degree-of-freedom dynamic model of the milling system is first formulated by introducing the axial contact angle. The tool axis is then discretized, so that the cutting force coefficients can be evaluated in different axial sections and the non-uniform distribution of cutting forces along the tool can be captured more accurately. After incorporating the regenerative mechanism, the milling dynamics are expressed in the form of a linear time-delay differential equation. To enhance the numerical accuracy of the time-delay system solution, a full-discretization scheme using third-order Lagrange–Hermite interpolation is developed for constructing the state transition matrix. The stability boundary is subsequently determined based on Floquet theory, from which the stability lobe diagram is generated. The proposed model and solution procedure are validated by comparison with existing methods and by time-domain simulation. The results show that, when the spindle speed ranges from 5000 to 10,000 rpm and the axial depth of cut ranges from 0 to 8 mm, the overall variation rate of the predicted stability region is 11.19% after incorporating axial discretization and 59.88% after considering the axial contact angle. The stable and unstable cutting responses obtained from time-domain simulations are consistent with the regions predicted by the stability lobe diagram, which supports the validity of the proposed approach. Further investigation shows that, for the established three-degree-of-freedom milling model and the specified cutting parameters, the axial contact angle exerts a pronounced nonlinear effect on the stability boundary. Specifically, as the axial contact angle $\epsilon$ increases within the range $0^{°}<\epsilon \le {45}^{°}$, the stable region gradually shrinks; when $\epsilon$ increases from 45° to 90°, the stable region expands instead. These observations can provide useful guidance for selecting milling parameters and identifying stable machining conditions. Full article

This paper addresses the finite-time global Mittag-Leffler projective synchronization problem for a class of uncertain fractional-order delayed neural networks with heterogeneous fractional orders, parameter uncertainties, and multiple time delays. A novel integral sliding mode control approach is developed by designing a delayed integral sliding manifold and an appropriate robust reaching law, such that the synchronization error trajectories are driven to the sliding surface within finite time. Furthermore, sufficient algebraic conditions are established to guarantee the global Mittag-Leffler stability of the reduced-order error dynamics on the sliding manifold. Under the proposed control scheme, finite-time projective synchronization is achieved in the presence of heterogeneous fractional orders, uncertain parameters, time delays, and nonlinear coupling effects. Finally, a numerical example is provided to demonstrate the validity and effectiveness of the proposed theoretical results. Full article