Search Results (782)

Objectives: To determine the prescribing prevalence of epidermal growth factor receptor (EGFR)- and anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC) patients in Greece and examine patterns of first-line tyrosine kinase inhibitor (TKI) utilization and associated treatment costs using nationwide real-world data. Methods: A retrospective analysis of the national e-prescription database was performed, identifying patients initiating first-line treatment (FLT) for EGFR- or ALK-positive NSCLC between 1 January 2020 and 31 December 2022. Demographic characteristics, prescribing prevalence data, drug utilization patterns, total annual drug expenditures, and per patient treatment costs were assessed. All statistical analyses were performed using the statistical software SPSS-v.29. Results: Overall, 1188 EGFR-positive (mean age of 70.93 ± 11.6) and 246 (mean age of 64.26 ± 12.6) ALK-positive NSCLC patients initiated FLT during the three-year study period. EGFR mutations were slightly more common in females (53%), peaking in the 70–79 age group (35%). ALK mutations were also more common among females (52%), particularly within the 60–79 age group. In EGFR-positive patients, osimertinib usage markedly increased from 41% in 2020 to 63% in 2022, primarily displacing afatinib (from 32% to 22%) and erlotinib (from 24% to 14%), with gefitinib prescriptions falling below 2%. Among ALK-positive patients, crizotinib utilization declined significantly from 60% to 16%, whereas alectinib increased to 59% by 2022. Annual EGFR-related total drug expenditures remained stable (€11.5 million in 2020 vs. €11.9 million in 2022), driven primarily by increasing osimertinib usage. Similarly, ALK-related annual drug expenditures showed stability, with costs predominantly attributed to rising alectinib utilization. Conclusions: This nationwide analysis highlights the rapid adoption of second- and third-generation TKIs for EGFR- and ALK-positive NSCLC in Greece, reflecting evolving clinical practice patterns. Although the target patient populations are relatively small, the associated economic burden is considerable. To ensure long-term sustainability of the Greek healthcare system, policymakers should critically assess the cost-effectiveness of these innovative therapies and align resource allocation with value-based care principles. Full article

This paper deals with static stability in planar grasps of an object by multiple fingers. Differently from previous research, we focus on the case that each finger has redundant links and joints. Based on contact constraints between the object and fingers, the relationships among displacements of object’s pose, contact positions, and joint positions are formulated. Using the constraints, the redundant joints are reduced to independent parameters. The relationship between the displacement and reaction torque of each joint is modeled as a linear spring, and potential energy of the grasp is formulated. Not only for frictionless sliding contact but also for pure rolling contact, we derive stable conditions on the contact positions and joint positions. Based on the conditions, partially differentiating the potential energy, a wrench (force and moment) vector and a stiffness matrix applied to the object by each finger are derived. Summing up the wrenches and matrices of all the fingers, we obtain a wrench vector and a stiffness matrix of the grasp, and we evaluate the grasp stability. Because of our analytical formulation, grasp parameters such as local curvatures at contact points, joint stiffnesses, etc., are explicitly included in the derived matrices. Partially differentiating the wrenches and matrices by the grasp parameters, we clarify effects of the parameters on the stability. Moreover, the difference between the frictionless sliding contact and pure rolling contact is derived in the wrench vector and the stiffness matrix. Using numerical examples, we validate our analysis. Full article

Schatzker type V bicondylar tibial plateau fractures present a major challenge due to the difficulty of achieving stable fixation with minimally invasive strategies. This study introduces a dual-thread lag and locking plate (DLLP) design that integrates lag screw compression with unilateral locking plate fixation. A custom-built compression evaluation platform and standardized 3D-printed fracture models were employed to assess biomechanical performance. DLLP produced measurable interfragmentary compression during screw insertion, with a mean displacement of 1.22 ± 0.11 mm compared with 0.02 ± 0.04 mm for conventional single lateral locking plates (SLLPs) (p < 0.05). In static testing, DLLP demonstrated a significantly greater maximum failure force (7801.51 ± 358.95 N) than SLLP (6224.84 ± 411.20 N, p < 0.05) and improved resistance to lateral displacement at 2 mm (3394.85 ± 392.81 N vs. 2766.36 ± 64.51 N, p = 0.03). Under dynamic fatigue loading simulating one year of functional use, all DLLP constructs survived 1 million cycles with <2 mm displacement, while all SLLP constructs failed prematurely (mean fatigue life: 408,679 ± 128,286 cycles). These findings highlight the critical role of lag screw compression in maintaining fracture stability and demonstrate that DLLP provides superior biomechanical performance compared with SLLP, supporting its potential as a less invasive alternative to dual plating in the treatment of complex tibial plateau fractures. Full article

Background/Objectives: Conductive hearing loss (CHL) recurrence or persistence after stapes surgery is often due to prosthesis displacement or malfunction, with malleus fixation being a less common cause. While persistent CHL linked to malleus fixation can be managed with appropriate diagnosis and surgical intervention, recurrent CHL cases remain poorly documented. This report describes a rare case of recurrent CHL due to malleus neck fixation, likely secondary to surgical trauma. Case Presentation: A 49-year-old woman underwent bilateral stapedectomy. CHL worsened after two years. CT showed right incus erosion and a left bony bridge. Revision surgery corrected the right side. Left tympanotomy revealed malleus fixation from a prior atticotomy. Removing the bony bridge restored ossicular mobility and hearing, stable at 6 and 12 months. Discussion: Malleus fixation after stapedectomy is rare and often related to congenital anomalies, chronic otitis media, tympanosclerosis, or surgical trauma. Bone dust or fragments from surgery may promote new bone formation, causing delayed fixation. Ossicular fixation can develop postoperatively and may be missed during primary surgery. High-resolution CT aids in diagnosis, especially in revision cases, while intraoperative palpation is key to detecting subtle abnormalities. Treatment options include ossicular mobilization, prosthesis revision, or chain reconstruction, tailored to the fixation’s location and severity. Conclusions: Surgical trauma should be considered a potential cause of recurrent CHL post-stapedectomy. Thorough removal of bone debris through aspiration and irrigation during surgery is essential to minimize this risk and optimize long-term hearing outcomes. Full article

Gel foam exhibits excellent applicability in fractured-vuggy reservoirs, effectively plugging flow channels and enhancing oil recovery. However, due to the harsh high-temperature environment and the complex and variable fracture-vuggy structure in reservoirs, gel foam may undergo structural changes during its migration, which can affect its flow properties and plugging efficiency. Therefore, investigating the migration characteristics of gel foam in fractured reservoirs through visual experiments is of significant practical importance. In this study, migration experiments with different foam systems were conducted using the visualized vuggy model. The migration stability of foam was characterized by combining the sweep range and liquid drainage rate, and the impact of temperature on the migration characteristics of gel foam was explored. Additionally, a profile control experiment was performed using the fractured-vuggy network model, analyzing and summarizing its mechanisms for enhancing oil recovery in fractured-vuggy reservoirs. The results showed that, in the vuggy model, compared with ordinary foam and polymer foam, gel foam showed a lower drainage rate, higher foam retention rate and wider sweep range, and could form stable plugging in fractured-vuggy reservoirs. An increased temperature accelerated the thermal expansion of gas and changes in liquid film characteristics, which led to the expansion of foam migration speed and sweep range. Although a high temperature increased the liquid drainage rate of foam, it was still lower than 3%, and the corresponding foam retention rate was higher than 97%. In addition, the gel foam had a strong profile control ability, which effectively regulated the gas migration path and improved the utilization degree of remaining oil. Compared with the first gas flooding, the recovery of subsequent gas flooding was increased by 18.85%, and the final recovery of the model reached 81.51%. Comprehensive analysis revealed that the mechanism of enhanced oil recovery by gel foam mainly included density control, foam regeneration, flow redirection, stable plugging, and deep displacement by stable gel foam. These mechanisms worked synergistically to contribute to increased recovery. The research results fully demonstrate the application advantages of gel foam in fractured-vuggy reservoirs. Full article

Background: Open fractures in pediatric patients are uncommon but clinically relevant, often resulting from high-energy trauma or sports-related incidents. This study analyzes the demographic patterns, types of sports, injury mechanisms, treatment strategies, and outcomes in children and adolescents with sports-related open fractures. Methods: In this retrospective study, 74 pediatric patients with sports-related open fractures treated at a level 1 trauma center between 2002 and 2023 were documented. Parameters such as age, sex, fracture location, sport type, treatment modality, complications, and outcomes were evaluated. Results: The cohort included 74 patients, with a mean age of 13 ± 3.6 years. Open fractures of the upper extremity were most common (seen in 34 patients). Moreover, 10 open craniofacial and 27 open nasal fractures represented 50.0% of injuries, mainly in male athletes involved in contact sports. Soccer was the leading injury-related sport (n = 14; 18.9%). Surgical treatment was required in 28 patients (37.8%), most frequently using elastic stable intramedullary nailing, Kirschner wire fixation in the upper extremities or nasal bone reduction. Antibiotics were administered in 46 patients (62.2%), with a mean documented duration of 2.7 ± 3.1 days. An excellent outcome was documented in 95%. Conclusions: Sports-related open fractures in children primarily affect male adolescents in contact sports and involve the upper extremities and facial region. Conservative management is effective in stable, non-displaced and low-grade injuries. Surgical treatment is frequently indicated in open forearm fractures. The implementation of a structured trauma care protocol, incorporating early debridement, definitive treatment, and antibiotics, has been demonstrated to yield a safe and effective treatment outcome with a favorable prognosis for sports-related open fractures in children. Full article

Friction dampers are widely used in building seismic protection due to their excellent shock-absorbing performance and reliable operation. To clarify the influence of friction plate material properties on the hysteretic behavior and stability of friction dampers, this study selected three materials with distinct physical properties (density, hardness, and stiffness)—titanium alloy, brass, and zirconia ceramic—as friction plate candidates. Three sets of low-cycle reciprocating load tests were designed to obtain the hysteretic curves of dampers with different friction plates and analyze their energy dissipation capacity and operational stability. Results show that the hysteretic curves of the copper-steel and titanium-steel plate specimens are close to the ideal rectangular shape, with symmetric force–displacement relationships and stable energy dissipation. The copper-steel plate exhibits strong energy dissipation capacity and high cost-effectiveness, while the titanium-steel plate has moderate energy dissipation capacity but stability comparable to that of the copper-steel plate. In contrast, the friction force of ceramic-steel plate specimens shows obvious divergence as displacement increases, leading to poor overall stability. The friction coefficient between the friction plate material and the main plate material exerts a significant influence on the damper’s energy dissipation, and a stable friction mode serves as a guarantee for its normal operation. Full article

By-pass switches play a crucial role in high-power electrical equipment, where reliable mechanical insertion and stable electrical contact are essential for safety and performance. However, few computational models have been developed to characterize the coupled mechanical–electrical behavior of by-pass switches with axially canted coil springs, which limits the understanding of their structural parameter effects. Motivated by this gap, this work investigates the mechanical insertion force and electrical contact resistance of by-pass switches with axially canted coil spring by combining analytical modeling and finite element simulation. The variations in mechanical insertion force, contact force and associated contact resistance as functions of the insertion displacement are presented. The total electrical contact resistance could comprise three components of resistance, that is, constriction resistance between multiple turns of coil spring wires and pin, constriction resistance between multiple turns of coil spring wires and V-shape groove, and the bulk resistance. The effects of structure feature parameters (including turns, spring wire diameter, inclination angle of axially canted coil spring wire, cylindrical pin chamfer radius and V-shape groove angle) are evaluated. Subsequently, the associated empirical formulas are established to guide the design of by-pass switches with axially canted coil springs. Full article

Slope instability in open-pit coal mines threatens safety and infrastructure. Displacement phenomena (cracks, deflection, heaving) signal potential failure. While counterweight backfilling stabilizes slopes, site-specific protocols for heterogeneous settings, such as Indonesia’s Barito Basin (Warukin Formation), lack standardization. This study addresses this gap at PT. Bhumi Rantau Energi’s Mahoni Pit by integrating high-resolution displacement monitoring (Leica Nova TM50), geotechnical analysis (RQD, RMR), and numerical modeling (SLIDE 7.0, RS2 v11). The objectives were to characterize the displacement mechanisms, quantify the counterweight effectiveness, and optimize the geometry. The results show “warning”-level velocities (>10 mm.h⁻¹) across points, with peak displacement (907 mm.day⁻¹ at IPD_MHN_26) driven by pore pressure in weak fill/mud layers (c′: 2–20 kPa; thickness: 71–100 m). Counterweights significantly increased the Factor of Safety (FoS) from critical levels (e.g., 0.960, PF = 74.4%) to stable values (e.g., 1.160, PF = 1.8%), representing 20–35% improvements. RS2 identified fill material as the primary displacement zone (max: 2.10 m). Optimized designs featured phased backfilling (200 k–10 M BCM) with a 50 m width and 11° inclination. Tailored counterweight deployment effectively mitigated the instability in slopes underlain by weak strata. The integrated approach provides a validated framework for optimizing designs in similar sedimentary basins, enhancing safety and reducing costs. Full article

In this study, a new type of double crosslinked nanospheres (DCNPM-A) was developed to solve the problem of gas channeling caused by fracture development in the process of CO₂ oil displacement, and the microsphere system with delayed swelling was successfully synthesized by inverse micro lotion polymerization. The microsphere adopts a dual crosslinking structure of stable crosslinking agent (MBA) and unstable crosslinking agent (UCA), achieving intelligent sealing function of shallow low expansion and deep high temperature triggered secondary expansion. The successful preparation of microspheres was verified by characterization methods such as Zeta potential and SEM, and the effects of reaction temperature, time, initiator and crosslinking agent dosage on microsphere properties were systematically studied. The experimental results show that DCNPM-A microspheres exhibit excellent expansion performance, thermal stability, and acid resistance in acidic, high-temperature, and high mineralization environments. Their expansion ratio can reach 13.5 times, and they can maintain stability for more than 60 days in supercritical CO₂ environments. Core displacement experiments have confirmed that the microspheres have the best sealing performance in matrices with a permeability of 10 × 10⁻³ μm² and fractures with a width of 0.03 mm. The combination of 0.8 PV injection volume, 0.5 mL·min⁻¹ injection rate, and continuous injection method significantly improved the plugging rate and recovery rate of CO₂ flooding. This study provides new technical support for the efficient development of low-permeability fractured reservoirs. Full article

Displacement ventilation systems can offer healthy indoor air quality (IAQ) by maintaining stratified flows that transport and expel airborne contaminants through the upper region of indoor spaces. Using large eddy simulation (LES), we investigate displacement ventilation in a generic indoor space under varying ventilation flow rates and supply–exhaust configurations. Assessing the ventilation system requires quantitative evaluation of airborne contaminants, for which CO₂ concentration is typically used as a proxy. However, in this study, we show that there is both a qualitative and quantitative correlation between CO₂ and airborne respiratory particles using computational particle fluid dynamics simulations. The role of the ventilation flow rate in ventilation efficacy is investigated for low values ranging from 0.01 to 0.06 m³/s, and the role of supply–exhaust configuration is assessed by considering in-line and staggered layouts. At low flow rates (0.01 to 0.04 m³/s), the ventilation system maintains a stable stratified layer within the room. Within this regime, the CO₂ level in the occupied zone is inversely proportional to the ventilation rate. At higher flow rates, the ventilation transitions to a mixing regime, effectively nullifying the intended design of the system. Interestingly, the two opening configurations produce nearly identical trends, suggesting that jet strength and room geometry dominate over modest opening shifts in this setup. Full article

This study proposes a precast concrete bridge pier system designed to enhance seismic resilience and post-earthquake reparability. The structural configuration integrates ultra-high-performance concrete (UHPC), externally replaceable steel-angle energy-dissipating components, and unbonded post-tensioned tendons. The seismic performance of the system was evaluated through quasi-static tests under cyclic loading. Experimental results demonstrated that the proposed pier exhibited stable hysteretic behavior and minimal residual displacement, effectively concentrating damage within the intended plastic hinge region. The superior strength of UHPC further contributed to improved load-bearing capacity and less localized concrete compressive damage at the rocking interface. The external steel angles improved the energy dissipation capacity of the precast column significantly, and its external arrangement made the post-earthquake replacement much easier as compared to internal energy dissipation bars. The feasibility of the proposed seismic-resilient pier system was successfully validated, offering a promising solution for bridge design in high-seismic-intensity regions. Full article

Substantial time-dependent deformation and support failure in deep tunnels through water-rich red-bed soft rock present critical engineering challenges, yet the underlying mechanisms under hydro-mechanical coupling remain inadequately quantified. This study integrates wireless remote monitoring, laboratory testing, and theoretical analysis to investigate the stress-deformation behavior of surrounding rock and support structures. Results reveal that deformation evolves through four distinct stages as follows: sharp, slow, stable, and creep, with the creep stage—governed by pore-water pressure—accounting for over 40% of total displacement. Groundwater-induced clay mineral hydration and stress redistribution significantly weaken rock self-support capacity. Support elements exhibit degraded performance; rock bolts suffer interfacial bond failure, steel arches yield asymmetrically, and the secondary lining resists transmitted deformation pressure. A novel deformation rate-based failure criterion is proposed, revealing a progressive “local breakthrough-chain transmission–global instability” failure pathway. These findings provide a theoretical basis for stability control in deep buried tunnels under hydro-mechanical coupling. Full article

The reactivation of the Longdongpo ancient colluvial landslide in Sinan County, Guizhou Province represents a typical multi-factor coupled failure. Based on detailed geological investigations and FLAC^3D fluid–solid coupling numerical simulations, this study reveals its complex reactivation mechanisms. The analysis demonstrates that long-term groundwater action has significantly weakened the slip zone at the soil–bedrock interface, causing strength degradation and inducing prolonged quasi-stable creep deformation of the slope. The artificial cut slopes formed in the middle-to-lower sections disrupted the original stress field and induced localized plastic deformation. Crucially, the numerical simulation identified a 5 m rainfall infiltration depth as the threshold triggering abrupt instability; when exceeding this critical value (simulated as 10 m and 16 m infiltration depths), pore water pressure surged (>2.7 MPa) and displacement dramatically increased (>2.2 m), reducing shear strength along the potential failure surface to critical levels. This process culminated in the full connection of the shear surface and the landslide’s catastrophic reactivation. This work quantitatively elucidates the chain-reaction mechanism of “long-term groundwater weakening → engineering disturbance initiation → critical-depth rainfall infiltration triggering”, providing vital quantitative evidence for regional ancient landslide risk prevention. Full article

Unconventional natural gas development requires a deeper insight into how CH₄ and CO₂ adsorb and diffuse in the pores of coal seams. Graphene (GRA) is frequently employed in microscopic mechanism simulations on coal surfaces because its structure closely resembles that of the coal seam matrix. In this study, molecular dynamics simulations were conducted to systematically investigate the diffusion, adsorption, and desorption behaviors of CH₄ and CO₂ within the pore system of hydrated graphene under three representative temperature and pressure conditions: 190 K-6 MPa, 298 K-0.1 MPa, and 320 K-8 MPa. The results show that heatinfg and depressurization significantly enhance the diffusion ability of gas molecules and promote their desorption from the graphene surface. Low temperature and high pressure are conducive to the formation of a stable adsorption layer, and more hydrogen bond structures are formed between CO₂ and water. However, under high-temperature conditions, this ordered structure is significantly weakened. The density distribution further reveals the spatial distribution characteristics of water molecules and gases and their evolution trends with changes in temperature and pressure. This research is conducive to a deeper understanding of the multiphase behavior of coalbed methane and its regulatory mechanism, providing theoretical support for the gas storage and displacement processes. Full article