Search Results (2,380)

Background: Two-stage revision arthroplasty is widely accepted as the reference standard for chronic periprosthetic joint infection (PJI) after total knee arthroplasty (TKA); however, reinfection or persistent infection occurs in a substantial subset of patients. We aimed to identify predictors of uncontrolled PJI following two-stage revision using an extended, single-center cohort. Methods: We retrospectively reviewed 177 knees with PJI after TKA treated with a uniform two-stage revision protocol between September 2011 and February 2022. Patients were classified as controlled (no further infection-related surgery or antimicrobial therapy ≥ 2 years after reimplantation) or uncontrolled (persistent infection after the first stage or reinfection after reimplantation). Demographics, comorbidities, laboratory parameters, perioperative factors, and microbiological characteristics were compared. Multivariable logistic regression with penalized estimation was used to identify independent predictors of uncontrolled infection. Results: Among 177 knees, 145 (81.9%) achieved infection control and 32 (18.1%) were classified as uncontrolled. On multivariable analysis using Firth penalized logistic regression, liver cirrhosis (odds ratio [OR] 9.87; 95% confidence interval [CI] 1.01–96.23; p = 0.049), the presence of a sinus tract at the first infection-control surgery (OR 3.47; 95% CI 1.43–8.40; p = 0.006), and fungal pathogens (OR 8.92; 95% CI 2.46–32.32; p = 0.001) were independently associated with uncontrolled PJI. Pre-reimplantation erythrocyte sedimentation rate (ESR) was significantly higher in the uncontrolled group on univariate analysis but was evaluated as a supportive marker due to limited availability in patients who did not undergo reimplantation. Demographic variables and most routine preoperative laboratory markers, including C-reactive protein before the first stage, were not independently associated with treatment failure. Conclusions: Liver cirrhosis, the presence of a sinus tract, and fungal infection are independent risk factors for uncontrolled PJI after two-stage revision TKA. Preoperative risk stratification incorporating host, local, and microbiological factors may assist in optimizing reimplantation timing, tailoring antimicrobial strategies, and improving patient counseling. Full article

Forest carbon sinks are central to climate change mitigation, and prior work has established a solid basis for assessing carbon sinks at regional scales. At the basin scale, however, forest carbon density (vegetation biomass carbon density, i.e., aboveground + belowground biomass carbon; t C ha⁻¹) often shows pronounced spatial clustering and inequality, while its temporal evolution and underlying mechanisms remain poorly quantified and interpreted for management-relevant units such as townships. Using the Xiuhe River Basin as a case study and townships as the basic analytical units, this study identifies the clustered spatial structure and inequality characteristics of forest carbon density and clarifies the joint effects of natural constraints and human disturbances, including potential threshold responses. We first assessed global spatial autocorrelation within a spatial weights framework using Global Moran’s I with permutation tests, and delineated local clustering by classifying local indicators of spatial association (LISA) types based on Local Moran’s I. We then measured the magnitude and stage-wise evolution of inter-township disparities using the Gini coefficient and the Theil T index. Finally, we applied GeoDetector factor, interaction, and risk detection to identify dominant drivers, interaction enhancement, and class-based contrasts. The results show significant and persistent positive spatial autocorrelation in forest carbon density from 2002 to 2024, with Moran’s I ranging from 0.68786 to 0.73849 (p < 0.01). Significant LISA units account for 40.74%–45.37% of townships, and the pattern is dominated by high–high (HH) and low–low (LL) clusters. Inequality follows a stage-wise trajectory: it expanded slightly during 2002–2019, converged markedly during 2019–2021, and rebounded modestly by 2024, while remaining below the levels observed in 2002 and 2019. Strong type-based differentiation is evident in 2024: mean carbon density is 46.06 t C ha⁻¹ in HH areas versus 17.64 t C ha⁻¹ in LL areas; HH areas contribute 38.44% of total carbon stock, whereas LL areas contribute only 5.08%. In terms of drivers, natural and human factors jointly shape the spatial pattern and commonly exhibit interaction enhancement. Elevation (q = 0.7832), slope (q = 0.7133), and NPP (q = 0.6373) are the leading natural constraints, while population density (q = 0.6054) and the built-up land ratio (q = 0.5374) are key indicators of human disturbance. Risk detection further indicates a stable negative gradient for the built-up land ratio and nonlinear class differences for population density, implying that once disturbance intensity reaches higher levels, low-value clustering is more likely to persist. By linking clustered spatial structure, stage-wise inequality, and disturbance-related threshold signals, our results support basin-scale zoning and differentiated management at the township level. Specifically, HH clusters should be prioritized for conservation and connectivity maintenance, whereas LL clusters warrant stricter control of built-up expansion and fragmentation to reduce the risk of persistent low-carbon locking under high disturbance. By linking spatial structure, inequality dynamics, and threshold responses, this study provides a quantitative basis for basin-scale zoning to enhance carbon sinks and for implementing differentiated spatial controls. Full article

Background: Focal chondral and osteochondral knee defects have limited intrinsic healing capacity and may progress toward post-traumatic osteoarthritis. Early post-operative inflammatory signaling may influence clinical recovery after cartilage repair. This prospective, single-center observational cohort study aimed to characterize short-term post-operative inflammatory biomarker profiles in synovial fluid and serum after AMIC and to assess associations with patient-reported outcomes over 12 months. Methods: Fifteen patients undergoing autologous matrix-induced chondrogenesis (AMIC) for focal knee chondral/osteochondral defects were prospectively enrolled. International Knee Documentation Committee (IKDC) and Lysholm scores were recorded pre-operatively and at 6 and 12 months. Synovial fluid and serum were collected intraoperatively, at 6 and 12 weeks post-operatively. Interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), and IL-6 were quantified using multiplex flow luminescence immunoassay, and the total synovial fluid protein level was measured. Non-parametric repeated-measures testing and Spearman’s rank correlation were applied (p < 0.05). Results: IKDC and Lysholm scores improved from (30.6 ± 9.4) to (58.8 ± 15.0) and from (57.5 ± 18.6) to (78.2 ± 14.7), respectively, exceeding established minimal clinically important difference (MCID) thresholds. Synovial fluid IL-1β and IL-1RA increased significantly over time ((p = 0.01357) and (p= 0.03953), respectively); IL-1β remained elevated, whereas IL-1RA tended to decline after 6 weeks. IL-6 levels remained low throughout. Total synovial fluid protein increased significantly (p = 0.00043). No significant correlations were observed between corresponding biomarker levels in synovial fluid and serum. Higher IL-6 and a higher IL-1β/IL-1RA ratio were associated with poorer clinical improvement (ρ = −0.80, p < 0.05 and ρ = −0.580, p < 0.05, respectively). Conclusions: AMIC was associated with a sustained intra-articular inflammatory response despite favorable 12-month outcomes. Exploratory analyses suggest that inflammatory dysregulation—particularly involving IL-6 and IL-1β/IL-1RA balance—may be linked to less favourable clinical recovery. Synovial fluid measurements provided more relevant information on local joint biology than serum sampling. Full article

Sluice gates are critical infrastructure for flood mitigation. During extreme floods, steel tubes from upstream sites can be transported downstream and impact radial gates, a scenario reported by operators but lacking systematic investigation. This study investigates the dynamic response and damage characteristics of a steel radial gate subjected to such impacts. A finite element model of an in-service radial gate was developed using shell elements. The Johnson–Cook constitutive model was adopted to capture the strain-rate hardening and to quantify the damage extent of Q235 steel. Numerical simulations were conducted across various impact scenarios, comparing the effects of a realistic steel tube against a mass-equivalent spherical impactor, and analyzing the influence of tube size, velocity, angle, and impact location. The results demonstrate that using a mass-equivalent spherical model yields unsafe estimates, underestimating the impact impulse and maximum total displacement by up to 10.58% and 26.16%, respectively, and under-predicting the damage parameter by as much as 51.53% in certain conditions. The maximum gate displacement (885.2 mm) occurs when the tube strikes near the top edge, while the most severe damage (parameter 0.53) is observed near the main crossbeam-support arm joint. The analysis further identifies two primary deformation modes under tube impact: local bending and a cantilever plate deformation. The latter, occurring at top-corner impacts, induces large displacements and forms a plastic hinge line, causing critical damage that is remote from the initial impact point. This research provides quantitative insights that are necessary for the anti-collision design and vulnerability assessment of radial gates. The findings underscore the need to consider realistic impactor geometry in structural analyses, contributing to enhanced risk management and the operational resilience of flood-control infrastructure during extreme flood events. Full article

This study presents a case-specific joining method for modular, large-scale components manufactured using Selective Laser Sintering (SLS). A T-slot joint reinforced with a pultruded carbon fiber rod was developed to enable the segmental assembly of polymer fan blades that exceed the build volume of common SLS printers. Through an iterative design process, five joint variations were investigated, focusing on the optimization of slot geometry (fillet radii and wall thickness) and the integration of carbon fiber reinforcements to create a high-strength hybrid connection. The experimental findings were validated using a non-linear finite element analysis (FEA) utilizing an iteratively calibrated Young’s modulus of 710 MPa, which accounts for the 50/50 virgin-to-reused PA2200 powder ratio employed in the study. The numerical model identified that the primary sites for crack initiation were the fillet radii of the female slot, where localized equivalent plastic strains reached critical levels of up to 84% in tension and 78% in bending. The final design achieved an average tensile strength of 27.6 MPa, exceeding the design threshold of 21.9 MPa with a safety factor of 2.5. While unreinforced joints showed a 73.4% reduction in bending strength compared to solid specimens, the addition of an 8 mm carbon rod increased performance by 238.7%, restoring over 90% of the monolithic material’s strength. Numerical results confirmed that the reinforcement assumed the primary load-bearing role, effectively mitigating stresses in the polymer matrix below the ultimate tensile strength. Failure analysis clarified that the observed audible failure originated from internal fiber breakage within the rod at stresses between 900–1050 MPa. This work demonstrates that a segmental, reinforcement-based joining method can effectively overcome size constraints in polymer additive manufacturing, providing a robust and repeatable solution for rotating components subject to complex loading conditions. Full article

Ground reaction force (GRF) is essential for maintaining dynamic stability and generating power during the golf swing. Traditional GRF assessment relies on force plates, limiting measurement to laboratory environments and restricting evaluation of natural, field-based performance. Recent work has explored wearable inertial measurement units (IMUs) and data-driven models to estimate GRF during simple locomotor tasks, yet no study has examined whether coupled lower-limb kinematics can predict three-dimensional GRF during complex, high-speed movements such as the golf swing. This study collected bilateral hip, knee, and ankle joint angles from IMUs, along with 3D GRF data, to evaluate five biomimetic deep learning (DL) architectures across seven sensor configurations. The TCN-BiGRU model achieved the highest accuracy (R² = 0.94 ± 0.02, MRE = 0.044 ± 0.01, NRMSE = 0.064 ± 0.01) among the architectures evaluated in this study, effectively capturing both local and long-range temporal dependencies in human movement. The full bilateral lower-limb configuration yielded the best overall performance, whereas using only the lead leg provided a cost-efficient alternative with minimal loss of accuracy. Among the GRF components, the vertical direction showed the greatest predictive reliability. These findings demonstrate the feasibility and potential of kinematic–force modeling and support the development of wearable, field-ready systems for GRF estimation in dynamic sports environments. Full article

Background/Objectives: The prevalence of joint replacement surgeries has significantly increased over the last century, leading to a corresponding rise in complications, particularly periprosthetic joint infection (PJI). The management of a PJI involves various strategies, including debridement, antibiotic therapy, and staged revision procedures. A notable advancement in treatment is the use of calcium sulfate reabsorbable carriers, recognized for their biocompatibility, osteoconductivity, and localized antibiotic delivery. Recent reports indicate that when combined with conventional treatment regimens, calcium sulfate carriers can achieve infection eradication rates exceeding 90%. This study aims to evaluate the efficacy of calcium sulfate carriers in managing periprosthetic infections, specifically assessing their impact on healing rates in patients undergoing treatment. Study Design & Methods: A retrospective analysis was conducted at our institution, focusing on patients diagnosed with PJIs treated with 2-stage revision surgery with local application of calcium sulfate carriers with antibiotics at both stages, and systemic antibiotic therapy, and comparing results with different surgical procedures. Results: The study included 40 patients (24 males and 16 females), with a mean age of 68.7 (range 48–87) years. The affected joints included the hip (27.5%), shoulder (27.5%), and knee (45%). The findings revealed that 97% of patients achieved infection eradication at the end of the follow-up period. Conclusions: These results highlight the complexities of managing PJIs and the significant role of calcium sulfate carriers in improving outcomes, supporting their use as a standard practice in confirmed PJI cases. Full article

This paper presents a comprehensive methodology for developing a numerical model of a masonry wall using the Non-Smooth Contact Dynamics (NSCD) method implemented in the open-source software LMGC90 version 2025. The modeling procedure relies on Python scripting and includes defining material properties, importing geometry from CAD tools, configuring the model, and specifying contact interactions between discrete elements. Each brick is modeled as an individual rigid element, allowing realistic simulation of frictional and cohesive behavior at joints. It outlines key theoretical aspects of the NSCD framework, including the formulation of global and local variables, interaction laws, and numerical integration. Numerical examples demonstrate the discrete element approach’s ability to capture complex in-plane and out-of-plane structural phenomena induced by seismic loading and differential foundation settlement. The results highlight the advantages of discrete modeling in representing discontinuities and failure processes that are difficult to simulate with a conventional continuum-based approach. Full article

Historic buildings exhibit coupled response characteristics during long-term service, characterized by slowly varying global inclination evolution superimposed with local component-level deformation. Meanwhile, multi-source measurements are susceptible to environmental noise and structural non-integrality, which poses challenges to obtaining stable and physically interpretable inclination measurements. To address these issues, this study proposes a multi-source fusion monitoring method for global inclination and local deformation of historic buildings using an extended Kalman filter with fractional-order state modeling (FEKF). A state-space model incorporating global inclination, local component-level additional deformation, and their projection relationships is established, in which global inclination information derived from Global Navigation Satellite System (GNSS) and local observations obtained from inclinometers are formulated within a unified measurement framework. Fractional-order dynamics are introduced into the state evolution model to represent the long-memory and non-stationary characteristics of structural responses in historic buildings. By adopting a finite-memory approximation, the fractional-order model is embedded into the extended Kalman filtering framework, enabling joint estimation and physical decoupling of multi-source measurements. Numerical simulation results demonstrate that the proposed method can stably separate global inclination and local deformation components under noisy conditions, while improving the stability of global inclination estimation. Further validation using measured data from a historic building shows that the fusion results effectively suppress high-frequency disturbances in GNSS measurements and allow reliable reconstruction of local component-level inclination responses, indicating good stability and practical applicability. These results demonstrate that the proposed approach provides a physically consistent and robust solution for long-term posture and deformation monitoring of historic buildings. Full article

The shear strength of rock discontinuities is critical for the stability of deep underground projects. However, its accurate determination is hindered by the discreteness of natural joints and the limitations of conventional direct shear tests, which operate under simplified two-dimensional stress conditions, unlike the true triaxial (σ₁ > σ₂ > σ₃) in situ state. This study introduces and validates a multistage true triaxial direct shear testing method as a practical solution. Through controlled pre-peak unloading, complete failure envelopes were successfully obtained from single specimens of jointed granite and intact marble with minimal strength degradation. The results demonstrate that lateral stress significantly enhances the peak shear strength, characterized by a marked increase in cohesion coupled with a slight decrease in the internal friction angle. For intact marble, increasing the lateral stress from 0 to 20 MPa raised the cohesion by approximately 67% (from 34.9 to 58.4 MPa), while the friction angle decreased from 49.3° to 42.8°. For jointed granite, cohesion showed a more variable but consistently strengthening trend with confinement, accompanied by a minor adjustment in the friction angle. Acoustic emission monitoring confirms that pre-peak unloading confines damage accumulation to microcrack reactivation. From a fracture mechanics perspective, the strength enhancement is attributed to the suppression of tensile crack propagation and the promotion of shear localization under three-dimensional confinement. Collectively, this work establishes a novel experimental framework and elucidates the mechanism by which lateral stress governs the shear behavior of hard rock, offering direct implications for the design and stability assessment of deep excavations and related geo-engineering projects. Full article

Background/Objectives: Thumb basal joint arthritis is a common degenerative condition often requiring surgery when conservative treatment fails. Dual mobility trapeziometacarpal prostheses are increasingly used, but the optimal anesthetic strategy remains debatable. This study aimed to explore whether WALANT provides intraoperative analgesia and short-term safety comparable to axillary block in dual mobility trapeziometacarpal arthroplasty. Methods: A prospective observational comparative study was carried out on 21 patients (11 WALANT, 10 axillary block) undergoing dual mobility trapeziometacarpal prosthesis for stage II–III in thumb basal joint arthritis according to Eaton–Littler classification at two hospital facilities of ASL Roma 5, from February–December 2025. Patients treated with the WALANT technique were assigned to Group A, whereas those undergoing an axillary block were assigned to Group B. Pain intensity was recorded on a 0–10 visual analogue scale at three stages: during anesthetic administration, during surgery, and 3 h after the procedure. Group A received a field infiltration with 1% mepivacaine combined with epinephrine 1:100,000 and sodium bicarbonate, while Group B underwent an ultrasound-guided brachial plexus block using 0.5–0.7% ropivacaine and a pneumatic tourniquet inflated to 250 mmHg. Results: Pain during anesthesia induction was similar between groups (Group A 3.18 ± 2.89 vs. Group B 2.20 ± 2.37, p = 0.393). Intraoperative pain did not differ significantly (Group A 2.27 ± 1.79 vs. Group B 2.00 ± 2.71, p = 0.898). At 3 h postoperative, Group B showed a trend toward lower pain levels (Group A 4.36 ± 2.54 vs. Group B 3.00 ± 3.08, p = 0.244). No anesthetic failures, no conversion to general anesthesia, and no neurological or ischemic complications occurred in either group. Conclusions: In this prospective observational comparative cohort, WALANT and axillary block provide comparable intraoperative analgesia for dual mobility trapeziometacarpal prosthesis, with comparable safety profiles. WALANT offers advantages in ease of administration, absence of tourniquet-related risks, and potential for intraoperative functional testing. Axillary block provides more prolonged postoperative analgesia in the first 3 h. The choice between techniques should be individualized based on patient-specific factors, anxiety profile, and local expertise. These results should be interpreted as preliminary and hypothesis-generating, given the exploratory design, the small sample size, and the limited statistical power of the study. Full article

Under practical operating conditions, intelligent fault diagnosis of permanent magnet synchronous motors (PMSMs) is often hindered by the shortage of effective fault samples. To address this issue, this paper proposes a twin-data-driven transfer learning-based diagnostic method for PMSM inter-turn short-circuit faults. First, a finite element model of the motor is established in Ansys to generate inter-turn short-circuit twin data, thereby enriching the source-domain samples. Second, continuous wavelet transform (CWT) is employed to convert stator current signals into multi-scale time–frequency feature maps, which are then fed into a feature extraction network constructed by integrating a residual network (ResNet) into an efficient channel attention mechanism (ECA) to achieve effective fusion of local and global time–frequency features. Finally, a joint loss function combining multi-kernel maximum mean discrepancy (MK-MMD) and a domain-adversarial neural network (DANN) is introduced to align feature distributions and perform adversarial optimization, enhancing cross-domain invariance and improving fault recognition capability. Experimental results demonstrate that the proposed REDM method achieves higher diagnostic accuracy and robustness than several existing intelligent fault diagnosis approaches. Full article

Background/Objectives: Streptococcus intermedius, a member of the Streptococcus anginosus group, is characterized by a marked propensity for abscess formation but only rarely causes native-joint septic arthritis. Involvement of the acromioclavicular (AC) joint is particularly uncommon. We describe a case of native AC joint septic arthritis due to S. intermedius in a patient with multiple predisposing factors and highlight diagnostic and management considerations. Methods: We report the clinical course of a 72-year-old man with poorly controlled type 2 diabetes mellitus who presented with progressive right shoulder pain, erythema, and swelling following recurrent minor skin abrasions from a newly adopted dog. Initial management for presumed inflammatory shoulder pathology included brief systemic corticosteroids and an ultrasound-guided intra-articular ketorolac injection. Magnetic resonance imaging (MRI) was performed after symptom progression. The patient underwent operative irrigation and debridement with collection of synovial fluid and deep tissue cultures. Blood cultures and transthoracic echocardiography were obtained to evaluate for systemic involvement. Results: MRI demonstrated multiloculated periarticular abscesses and osteolysis centered on the AC joint. Operative cultures yielded high colony counts of S. intermedius from synovial fluid and deep tissues. Blood cultures and echocardiography were negative. The patient required multiple operative debridements with irrigation, adjunctive local antibiotic therapy, and prolonged targeted β-lactam treatment. Clinical and radiographic improvement was achieved following surgical source control and antimicrobial therapy. Conclusions: Native AC joint septic arthritis due to S. intermedius is rare. Older age, uncontrolled diabetes, recent intra-articular intervention, and possible zoonotic inoculation from canine wound licking may represent contributory risk factors. Early imaging, prompt surgical source control, and guideline-concordant antimicrobial therapy are essential when bone and soft tissue involvement is present. Full article

In this paper, we propose a distributed admittance control framework for joint manipulation of objects by multiple robotic arms that addresses the challenges of human–robot interaction. The system is developed to control the joint transportation of an object by N Franka Emika Panda robots (validated with up to four in simulations) using external human force estimation in a distributed manner without relying on centralized computation or force sensors. We integrate a hybrid observer by combining a distributed force estimator with a nonlinear disturbance observer (NDOB) to achieve accurate human force estimation and minimize estimation errors in simulations. Adaptive radial basis function neural networks (RBFNNs) are employed to dynamically adjust the damping and inertia parameters, enhancing the system’s adaptability and stability. Event-based communication minimizes network bandwidth usage, while consensus protocols ensure synchronization of state estimates across robots. Unlike conventional methods, the proposed observer operates in a fully sensorless manner: no human-force measurements are required. The estimation relies solely on locally available robot states, maintaining high accuracy while reducing system complexity. The framework demonstrates scalability to multiple robots, enhancing robustness in distributed settings. Simulation results show superior performance in terms of path tracking, force estimation accuracy, and communication efficiency compared to centralized approaches. Specifically, the event-triggered strategy reduces communication messages by approximately 70% compared to always-connected mode while maintaining comparable RMSE in position $(9.97\times {10}^{-5}$ vs. $7.39\times {10}^{-5}$) and velocity $(2.52\times {10}^{-5}$ vs. $3.76\times {10}^{-5})$, outperforming periodic communication. Full article

Event cameras provide microsecond-level temporal resolution, low latency, and high dynamic range, enabling robust perception under fast motion and challenging lighting conditions. Nevertheless, event streams are susceptible to background activity, thermal noise, and hot pixels. Their sparse and irregular patterns can corrupt event structures and degrade downstream tasks. We propose MSF, a multi-level spatiotemporal filtering framework that couples motion-compensated aggregation with neighborhood-level verification. In each temporal window, MSF estimates a constant 2D optical flow by maximizing a robust, density-normalized contrast objective on the image of warped events (IWE). We further incorporate polarity–gradient decorrelation to suppress mixed-polarity noise and an explicit peak-suppression regularizer to avoid hot-pixel-induced degeneracy. The motion parameters are optimized via coarse grid initialization followed by gradient-ascent refinement. Based on the estimated motion, MSF performs hierarchical event selection: central events are extracted from high-confidence aggregated regions, local events are recovered through joint spatial–temporal–directional–polarity consistency, and weak border events are identified using a density-normalized probabilistic support model that rewards support from reliable structures while penalizing self-clustering. Experiments on four public benchmarks (DVSNOISE20, DVSMOTION20, DVSCLEAN, and E-MLB) show that MSF consistently improves the Event Structural Ratio (ESR) and outperforms representative baselines across diverse motion regimes and severe low-light noise. Full article