Search Results (1,540)

Objectives: Osteoarthritis (OA) of the medial compartment in varus knee is a common degenerative condition. High tibial osteotomy (HTO) has been recognized as a primary joint-sparing procedure. The aim of this systematic review was to investigate functional and radiological outcomes, complications, and the progression of knee OA in patients undergoing medial opening wedge HTO. Methods: A total of 18 studies were included. Patients’ demographics, Knee Injury and Osteoarthritis Outcome Score (KOOS), number and types of complications, conversion in arthroplasty surgery rate, survival rate, and radiological evaluation were recorded. Results: A total of 2683 patients were evaluated. The frequency-weighted mean follow-up was 168.6 ± 54.6 months. The mean preoperative KOOS score was 46.5 ± 19, while postoperatively the mean score was 66.4 ± 22.9 (p < 0.001). The pre- and postoperative mTFA angle was −5.7° ± 2.8°, and 1.4° ± 2.4°, respectively; with a statistically significant improvement (p = 0.002). A total of 12.5% of patients had a conversion to a total knee arthroplasty and 1.5% had a conversion to unicompartmental knee arthroplasty, while 1.3% of the patients had a revision surgery unrelated to arthroplasty. The survival rate after 10 years was 86.3%. The nonunion rate was 1.3% and the infection rate was 0.9%. Conclusions: Patients who underwent medial opening wedge HTO achieved a significant correction of mTFA associated with an improvement in functional outcomes. An 86% survivorship rate at 10 years was observed, while a 14% conversion rate to knee arthroplasty for OA progression was reported after a mean follow-up of 14 years. Full article

Background: Reliable intraoperative tools for donor liver assessment are needed, particularly in the context of steatotic and extended-criteria grafts. While histology remains the reference standard, it is limited by sampling variability and logistical constraints. Preservation fluid may provide a complementary, whole-organ source of biochemical information. Methods: In this single-center prospective exploratory pilot study, liver tissue and preservation fluid were collected from 30 donation-after-brain-death grafts during the back-table procedure. Biochemical parameters, including arginase activity, β-hydroxybutyrate (βHB), acetoacetate, and total protein, were measured using standard assays. Associations with histological steatosis on wedge biopsy were assessed using nonparametric correlation analyses, and paired preservation fluid samples were compared. Results: Most grafts demonstrated absent or mild steatosis; only two exhibited moderate steatosis, and none were severely steatotic. No preservation fluid biomarker showed a statistically significant association with histological steatosis. Weak, non-significant positive correlations were observed for βHB and arginase activity (Spearman r ≈ 0.33–0.35). Protein concentration and arginase activity decreased between start and end samples, whereas ketone body levels remained relatively stable. Conclusions: Preservation fluid biomarker measurement during routine graft preparation is feasible. Although no significant associations with histological steatosis were identified, the observed weak correlations suggest possible associations requiring validation in larger studies. Larger, adequately powered studies, including a broader spectrum of steatosis and clinically relevant outcomes, are required to determine potential clinical applicability. Full article

A comparative study on hemicircular tibial plateau leveling osteotomy (hTPLO) and TPLO for correcting cranial cruciate ligament (CCL) ruptures at excessive tibial plateau angles (eTPAs) was performed with a specially fabricated hTPLO saw blade (hemicircular) and TPLO saw blade (quartercircular), respectively. Ten 3D-printed bone models with eTPAs (TPA > 40°), were resized to accommodate the respective saw blade shape for each method. Cranial closing wedge osteotomy (CCWO) combined with TPLO was also performed. Distances of segment rotation below the patellar tendon insertion (PTI) and differences between anatomical and mechanical axes after correction were measured. The TPAs of the bone models were 46.06 ± 4.40° (40.0–50.7°). Postoperative TPAs of hTPLO, TPLO, and TPLO combined with CCWO were 4.93 ± 1.025°, 4.52 ± 0.085°, and 4.17 ± 1.128°, respectively. Rotation distances from the PTI were 0.46 ± 2.153 mm, 8.67 ± 2.318 mm, and 1.13 ± 1.796 mm, respectively. hTPLO showed significantly less movement of the segment below the PTI than TPLO with or without CCWO (p < 0.01). Differences between anatomical and mechanical axes after hTPLO and TPLO with or without CCWO were 5.74 ± 2.231°, 6.43 ± 2.105°, and 5.16 ± 2.465°, respectively. Within the limitations of this model-based study, hTPLO demonstrated geometric feasibility for correction of excessive tibial plateau angles and was associated with less rotational displacement of the proximal tibial segment relative to the patellar tendon insertion than conventional TPLO and TPLO combined with CCWO. Further cadaveric, biomechanical, and clinical studies are required to evaluate its safety and clinical applicability. Full article

Hypersonic air-breathing propulsion via the Oblique Detonation Wave Engine (ODWE) offers superior thermodynamic efficiency compared to conventional scramjets by utilizing a stationary oblique detonation wave (ODW). While fundamental research has predominantly focused on two-dimensional planar wedges, realistic applications feature axisymmetric conical configurations. Over a cone, radial Taylor–Maccoll (TM) compression decelerates the flow and, in the mixed flow regime, establishes a localized subsonic pocket near the cone surface. However, the unsteady structures, triple-point kinetics, and cellular evolution under the competing influences of stabilizing TM compression and destabilizing Prandtl–Meyer (PM) expansions induced by a finite-length cone remain poorly understood. To address this gap, high-resolution numerical simulations of axisymmetric conical ODWs on a finite cone (semi-cone angle θ = 49°) were conducted at an inflow Mach number of Ma₀ = 7.5 using OpenFOAM. The methodology solves the reactive Euler equations coupled with a single-step Arrhenius model and three levels of adaptive mesh refinement to resolve fine-scale wave structures. Numerical results reveal that the localized subsonic pocket completely obliterates the smooth ZND-like initiation zone typical of purely supersonic configurations. Within this subsonic channel, acoustic disturbances propagate upstream against the bulk flow at a relative velocity of c − u, bypassing the supersonic wave-blocking effect to continuously impinge upon the detonation front. This acoustic feedback loop disrupts shock–reaction coupling, accelerating wave front bifurcation into single triple-point, dual triple-point, and PM-affected segments. Shock polar analysis validates that upstream-facing triple points exhibit greater shock strength, driving slow upstream migration and causing adjacent triple points to collide and reform into distinct, chaotic cell morphologies. Trajectory tracking confirms that the mixed flow cells are substantially larger and more chaotic than supersonic cases, directly reflecting amplified perturbations from the subsonic pockets. These insights provide crucial design criteria for optimizing cone angles to suppress irregular modes and stabilize conical ODWs. Full article

Clustering is the process in Wireless Sensor Networks (WSNs) used to make the routing process efficient and for selecting the optimized path for sending the data, considering metrics like energy consumption and node distance. Many clustering routing algorithms are addressed for selecting the best path. Among them, Progressive Index Modulation in Intra cluster and Inter cluster routing algorithms uses the index shifting technique for distributing the cluster head role among the sensor nodes. Because of static node deployment, WSN causes the energy hole formation. Hence, this manuscript proposes an Equiangular Wedge Energy Hole Detection (EWED) algorithm for multi-hop WSNs to detect and prevent energy holes. In the hole detection phase, the network region is split into equiangular wedges, where each node serves as a generating point in the geometry to create a Region of Interest (ROI). Finally, the simulation results reveal that the EWED achieves higher network performance compared to the existing clustering routing algorithms. Full article

This paper aims to analyse the microstructure and properties of the titanium- and boron-alloyed high-carbon medium-manganese 140Mn6Cr3TiB steel deposit before and after high-frequency mechanical impact (HFMI) treatment. XRD, SED, and EDS analyses were applied to evaluate the microstructural peculiarities of the studied deposit. Nanoindentation and scratch/sliding tests respectively revealed distinct correlations between the phase composition and the deformation/wear behaviour. HFMI results in the formation of the strain-induced ε- and α’-martensites (~66% and 3–6%, respectively), a significant grains/crystallites refinement (down to 31–54 nm), and dislocation density, which support essential hardening (by ~50%). The HFMI regime (load = 100 N, amplitude = 10 µm, and time = 60 s) was found to be the best, which led to the enhanced wear resistance (decreased wear volume) by ~4 times. The heterogeneous nature of the steel deposit creates a “shield-and-buffer” effect, where the hard eutectic framework resists penetration and tough matrix prevents brittle failure, maintaining a high tolerance to abrasion damage. The HFMI-hardening changed the wear mechanism from the ‘wedge/pile-up’ formation to ploughing. Thus, the HFMI shows a good efficiency in finishing the protective medium-manganese steel deposits of enhanced wear resistance to prolong the operation life of responsible parts. Full article

Virtually all spaceborne topographic lidars to date have used a single beam, with the exception of the ATLAS lidar on NASA’s ICESat-2 satellite, which split the beam into 3 “strong” and 3 “weak” beamlets distributed perpendicular to the along-track path of the satellite. This approach has provided high-resolution along-track surface measurements but relatively poor resolution cross-track measurementswithin a given surface area. The present paper attempts to resolve this discrepancy by (1) transmitting and scanning a single Gaussian beam and (2) imaging the return onto a 14 × 14 pixelated, single-photon sensitive, detector array, thereby providing between 100 and 196 measurements per pulse, depending on the solar background. Besides enhancing the lidar’s capability to penetrate tree canopies and water bodies, the proposed single-beam approach provides one to two orders of magnitude more measurements per pulse with equal spatial resolution in boththe along-track and cross-track directions. At the 10 kHz pulse rate of the ATLAS laser on NASA’s ICESat-2 satellite, this implies between 1 and 2 million topographic measurements per second. The maximum surface area observable by a single pulse increases with the laser peak power defined by the ratio of the pulse energy to the temporal pulsewidth. Larger surface areas per pulse result in more time for cross-track scanning while still maintaining contiguous along-track mapping. Two scanning methods appear to be feasible: (1) circular scans using individual but temporally coordinated wedge scanners for the transmitted and received beams, and (2) unidirectional linear scans utilizing Acousto-Optic Deflectors. The circular scan approach is probably easier to implement, but it also requires additional post-processing to obtain an accurate contiguous 3D image of the planetary terrain. Full article

Background and Objectives: Foot wedges are widely used to modulate ankle alignment in clinical and athletic settings, yet the effects of mediolateral wedge placement on multi-planar lower limb biomechanics during functional unilateral exercises remain poorly characterized. This study aimed to quantify the effects of medial and lateral foot wedge placement on lower limb joint kinematics, muscle activation, and ground reaction forces (GRFs) during the split squat. Materials and Methods: Thirty healthy young adults (12 males, 18 females; 24.5 ± 2.7 years) performed split squats under three randomized conditions using a rigid inclined platform rather than a custom foot orthosis: no wedge (NW), medial wedge (MW), and lateral wedge (LW). Three-dimensional kinematics (Qualisys, 100 Hz), bilateral GRFs (Bertec, 1000 Hz), and surface electromyography (sEMG, 1000 Hz) of the peroneus longus (PL), tibialis anterior (TA), vastus medialis (VM), and vastus lateralis (VL) were recorded synchronously. Repeated-measures ANOVA with Bonferroni post hoc tests and partial eta-squared (η²_p) were used (α = 0.05). Results: LW significantly increased PL and VM activation, sagittal-plane range of motion (ROM) at the ankle, knee, and pelvis, and vertical GRF, compared with MW and NW (p < 0.05). MW significantly increased TA and VL activation and reduced sagittal hip ROM (p < 0.05). No significant differences were observed for mediolateral or anteroposterior GRF. Conclusions: Mediolateral foot wedge placement acutely reorganizes lower limb neuromuscular recruitment, joint kinematics, and vertical ground reaction force during the split squat in healthy young adults. These preliminary findings indicate that wedge orientation, applied via a rigid inclined platform, can acutely and selectively modulate muscle activation patterns; any therapeutic or performance applications, however, were not evaluated here and should not be generalized to conventional clinical orthoses without further investigation. Full article

By using a PMMA-made therapeutic wedge and a recently developed reusable silicone foil dosimeter based on the optically stimulated luminescence (OSL) of MgB₄O₇:Ce,Li (MBO) material, direct measurements of the complete proton Bragg curves for two independent clinically relevant proton beams were achieved. The PMMA wedge compensator created a controlled range gradient across the beam field, enabling comprehensive characterisation of Bragg curve features, including the entrance plateau, the maximum of the Bragg peak, and the dosimetrically critical distal fall-off region. Measurements were performed using a dedicated, self-built (3D-printed) optical detection setup equipped with a blue LED (440 nm) that illuminates the MBO foil dosimeter and a highly sensitive electron-multiplication (EMCCD) camera, which simultaneously acquires 2D OSL light from the foil. The prototype technology enables single-shot 2D mapping of the complete Bragg curve. Validation against Monte Carlo (MC) simulations and Gafchromic^TM EBT3 films demonstrates sub-millimetre accuracy in localising the clinically critical proton parameters: peak-to-plateau, FWHM and distal fall-off. Measurements were performed for two independent therapeutic proton beams with initial energies of 58.8 and 61.1 MeV, routinely used for proton eye-beam treatments at IFJ PAN Krakow. As a proof of concept, the results demonstrate the potential of MBO-based silicone foil technology to reproduce clinically relevant Bragg-curve parameters with accuracy approaching that of the current gold standard for passive 2D dosimetry, Gafchromic^TM EBT3 films, while systematic differences attributable to optical diffusion, residual LET-dependent quenching, and the dual-foil junction remain to be corrected. Full article

Ensuring face stability is a pressing concern in slurry shield tunneling under high water pressure. Although slurry infiltration and filter cake formation are known to affect stability, the governing role of seepage forces in the failure mechanisms remains insufficiently understood, and existing models often oversimplify the regulating effect of filter cake permeability. To address this gap, a combined numerical–theoretical approach is developed that explicitly incorporates seepage effects into the failure analysis. A three-dimensional seepage model was developed to simulate transient pore water pressure distribution ahead of the tunnel face, considering filter cake properties, stratum permeability, and applied slurry pressure. Based on the computed seepage field and a wedge-prism composite failure mechanism, an upper-bound limit analysis model was formulated that accounts for the work done by seepage forces. Results reveal a filter cake permeability threshold of 1.0 × 10⁻⁷ m/s, below which further reduction yields negligible stability improvement. Parametric studies quantify the influences of internal friction angle, cohesion, depth-to-diameter ratio, and permeability contrast between soil and filter cake. Validation against field data from the Maliuzhou Tunnel demonstrated that the calculated limit pressures consistently lie below the field-measured slurry pressures, confirming the model’s reliability and its practical utility for guiding slurry pressure selection in complex ground conditions. Full article

The Holocene evolution of organic carbon (OC) sources in the North Yellow Sea remains poorly constrained. In this study, a sedimentary dataset from core WHD01 retrieved from the Shandong Peninsula Mud Wedge is presented. After correcting grain-size, diagenetic and provenance biases in geochemical proxies and removing diagenetic offsets of sedimentary δ¹³C signals, the MixSIAR Bayesian mixing model was used to quantify three OC endmembers. The results reveal three distinct evolutionary stages of OC composition: pre-10 cal ka B.P. dominated by terrestrial C₃ OC; 10–4.2 cal ka B.P. dominated by marine OC during rapid sea-level rise; post-4.2 cal ka B.P. marine-derived OC remained dominant while C₃ terrestrial and estuarine OM increased alongside enhanced OC burial, driven by anthropogenic catchment erosion and improved organic preservation. Temporal shifts in OC source apportionment and burial flux are tightly coupled to East Asian Summer Monsoon variability and sea-level change, with conspicuous OM compositional reorganizations coinciding with the 8.2 ka and 4.2 ka climatic cold events. Full article

Cranial cruciate ligament (CrCL) rupture in cats is less common than in dogs, and its optimal treatment remains a subject of debate. This study aimed to evaluate the application of cranial tibial wedge osteotomy (CTWO) as a dynamic stabilization technique in cats with CrCL rupture, describing the technical aspects and clinical outcomes obtained. Five cases with a confirmed diagnosis of CrCL rupture between 2020 and 2024 were included in this study. All patients were treated with CTWO using specific osteosynthesis locking plates designed for use in dogs and a complementary cerclage wire. Radiographic rechecks were performed at 8 and 12 weeks postoperatively, and clinical evaluations were performed 24 h, 8 weeks, 12 weeks, and 6 months postoperatively in every patient. Successful and complete bone healing of the tibial osteotomy was observed in every case. No intraoperative or postoperative complications related to implants or soft tissues were recorded. All cats achieved complete functional recovery without lameness at the last recheck six months after surgery. The technique was performed without significant technical difficulties, providing adequate stability and favorable clinical outcomes in all cases. These preliminary results support the use of CTWO as an effective surgical alternative for the treatment of CrCL rupture in cats. However, further studies with a larger number of cases and a longer follow-up are required to better evaluate its clinical application, outcomes, and influence on osteoarthritis progression in the long term. Full article

This study conducts a multi-objective optimization of an impact pruner for coniferous plantation trees, using Prince Rupprecht’s larch (Larix principis-rupprechtii Mayr) in North China as a case study. The objective is to establish an impact cutting mechanics model and to construct an impact cutting platform. This study utilizes the Box–Behnken principle, with the cutting speed (v), cutter wedge angle (β), and cutting clearance (L) as influencing factors and the cutting energy consumption (Y₁), total equipment energy consumption (Y₂), and specific cutting area (S) as evaluation indexes. The cutting parameters were optimized using a mathematical model for multi-objective optimization. The experimental results indicate that the factors influencing target Y₁ were ranked as β, L, and v, while the factors influencing target Y₂ were ranked as β, v, and L, and the factors influencing target S were ranked as L, β, and v. Field tests demonstrated that the optimization reduced the cutting energy consumption by up to 16.90% and improved the cutting quality by up to 19.28%. These gains directly translate to improved operational efficiency and economic value in forestry management. The optimal parameters corresponding to these improvements are v = 2.15 m·s⁻¹, β = 20°, and L = 5 mm, resulting in Y₁ = 36.10 J, Y₂ = 3351.01 J, and S = 3.45. These results demonstrate the feasibility and efficiency of the impact pruning method for Larix principis-rupprechtii in coniferous plantation forests. By combing mechanism analysis with multi-objective optimization, this study proposes a solution that can improve the pruning quality of coniferous plantation trees, reduce the energy consumption of impact pruning machines, enhance tree health, and serve as a measure to prevent pests and diseases, contributing to the advancement of artificial forest plant protection technology. Full article

Background and Objectives: Conventional supramalleolar osteotomy (SMO) often involves a concomitant fibular osteotomy (FO), which carries risks, such as nonunion and nerve injury. We evaluated the clinical and radiological outcomes of a fibula-preserving SMO (FP-SMO) combined with arthroscopic modified Broström operation (MBO) in patients with medial compartment varus ankle osteoarthritis and chronic lateral ankle instability. Materials and Methods: We retrospectively reviewed 22 patients who underwent medial opening wedge FP-SMO and arthroscopic MBO between 2014 and 2019. Clinical outcomes were assessed using the Visual Analog Scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score, and Foot and Ankle Outcome Score (FAOS). Radiological evaluation included the anterior drawer test (ADT), talar tilt angle, tibiotalar surface (TTS) angle, medial distal tibial angle (MDTA), tibial lateral surface (TLS) angle, Takakura stage, and International Cartilage Regeneration and Joint Preservation Society (ICRS) grade assessed during second-look arthroscopy. Results: At a mean follow-up of 17.22 months, the mean VAS, AOFAS, and FAOS scores improved significantly (p < 0.001). Radiologically, the mean ADT decreased from 5.98 mm to 4.70 mm (p = 0.015), and the mean talar tilt angle decreased from 9.85° to 6.09° (p < 0.001). The mean TTS angle increased from 80.46° to 84.86° (p = 0.021), and the mean MDTA increased from 85.03° to 91.26° (p < 0.001). The TLS angle showed no significant change from 81.17° to 81.54° (p = 0.238). Takakura stage and ICRS grade improved or remained stable in all patients. No major complications, including nonunion, were observed. Conclusions: FP-SMO combined with arthroscopic MBO demonstrated favorable short-term clinical and radiological outcomes in selected patients with medial compartment varus ankle osteoarthritis and chronic lateral ankle instability. This combined approach may be a feasible joint-preserving option that addresses coronal malalignment and lateral ankle instability without requiring FO; however, longer-term comparative studies are needed to confirm its durability and clinical utility. Full article

Background: Some widely used wildland fire behavior models, like the Fire Area Simulator (FARSITE), propagate fire fronts by computing the front-normal velocity (spread rate) as a function of local inputs and the front-normal direction. Such models are sometimes observed to cause the collapse of crown fires into sharp wedge shapes that eliminate heading fire behavior. Aims: We set out to document this phenomenon and, more generally, understand the relationships between fire shapes and spread rate functions. Methods: The phenomenon is studied both mathematically and through simulation experiments. Non-smooth fire fronts are theorized mathematically by an Eikonal partial differential equation ($H(x,\tau ,D\tau )=1$), where the unknown $\tau \left(x\right)$ is the time-of-arrival function and the Hamiltonian $H(x,t,p)$ is positively homogeneous and possibly non-convex in p; convex analysis is used to study viscosity solutions in constant conditions. Results: We show that a fire spread model preserves the smoothness of fire fronts if and only if it is equivalent to using the Huygens principle. Nontrivially, this is equivalent to a convexity criterion on the inverse spread rate profile, which is then the polar dual of the Huygens wavelet; this corresponds to Hamiltonian–Lagrangian duality. The relevance of smoothness-destroying models to crown fire is debated. Exact analytical formulas are derived for fire growth in constant conditions. Conclusions: Our understanding of fire spread models is improved by solving the spread equations in more general ways than previously known. In particular, the collapse of heading crown fires into sharp shapes is now explained. Smoothness-destroying spread models cannot be simulated by algorithms based on travel time like cellular automata; their general well-definedness remains an open question. Fire modelers can use these findings to guide their search for improved crown fire models, and more generally to verify the accuracy of numerical implementations. Full article