The impact of competition mechanisms on primary school students' digital game-based mathematics learning.

The development of low-carbon binders requires optimized formulations that balance mechanical performance, durability, and environmental impact. This study investigates the multi-criteria optimization of slag-based geopolymer mortars incorporating ground granulated blast furnace slag (GBFS), cement kiln dust (CKD), and glass powder (GP) as ternary precursors. A multifactorial Central Composite Design (CCD) coupled with Response Surface Methodology (RSM) was employed to evaluate the individual and interactive effects of CKD and GP (0–30%) on fresh, mechanical, dimensional, microstructural, and environmental properties. Nine formulations were produced and tested for flow spread, compressive strength (7 and 28 days), open porosity, drying shrinkage (56 days), mass loss, and carbon footprint. The developed statistical models showed high reliability (R² = 0.94–0.97; p < 0.01). Incorporation of 15% GP reduced open porosity from 14.23% to 11.1% and increased 28-day compressive strength by 20.3%. In contrast, 30% CKD increased porosity to 17.85% and drying shrinkage above 1.10‰. GP at 30% minimized shrinkage to 0.82‰ and reduced mass loss to 3.2%. Multi-response optimization identified an optimal composition of 17.91% CKD and 25.34% GP, achieving 47.67 MPa at 28 days, 185.26 mm flow spread, 13.86% porosity, 962 µm/m shrinkage, and a carbon footprint of 143.8 kg CO 2 /m 3 . Microstructural analyses (XRD, DTG, SEM–EDX) confirmed the formation of hybrid C-(N)-A-S-H gels responsible for matrix densification. The novelty of this work lies in the integrated mechanical–microstructural–dimensional–environmental optimization of a ternary geopolymer system through a statistically validated multi-response framework, providing a comprehensive methodology for sustainable construction materials design. • Ternary geopolymer mortars based on GBFS, CKD, and GP were optimized using CCD. • Synergistic CKD–GP interactions improved strength and matrix densification. • ∼15% GP increased compressive strength and reduced porosity and shrinkage. • Alkaline activators dominated the environmental footprint.

All screens lead to polo-like kinase 1: A central node in cancer therapeutics and resistance.

OBJECTIVES:Understanding the mechanistic impact of fostamatinib, a spleen tyrosine kinase inhibitor, in severe COVID-19 using biomarkers associated with disease severity is crucial for the development of host-directed therapeutics. We analyzed samples from a randomized clinical trial to investigate the impact of fostamatinib on multiple inflammatory biomarkers associated with COVID-19 disease severity.DESIGN:Secondary analyses of biomarkers from a randomized clinical trial.SETTING:Multicenter randomized clinical trial.PATIENTS:A total of 400 adults hospitalized with COVID-19 were enrolled in a phase 3 randomized clinical trial. Absolute neutrophil counts (ANCs) were analyzed across 392 patients and biomarkers were measured in 190 patients with available plasma samples.INTERVENTIONS:Adults hospitalized with COVID-19 were randomized to receive either fostamatinib (150 mg bid) or placebo. ANCs and 24 biomarkers were assessed at day 0 and over time using a multiplexed Meso Scale Discovery assay (Meso Scale Diagnostics LLC, Rockville, MD).MEASUREMENTS AND MAIN RESULTS:At day 0, participants with World Health Organization ordinal scale 5–7 had elevated ANC counts, compared with ordinal scale 4. In addition, the levels of neutrophil-associated biomarkers, inflammatory cytokines, and mediators of endothelial dysfunction at day 0 were increased in the participants who were ordinal scale 5–7 vs. ordinal scale 4. Randomization to fostamatinib compared with placebo resulted in a decrease in ANC and several neutrophil-associated biomarkers, pro-inflammatory cytokines, and mediators of endothelial dysfunction/tissue damage. This differential finding was also demonstrated in a subgroup of patients (n = 85) with a hypoinflammatory phenotype.LIMITATIONS:Missing plasma samples and neutral phase 3 trial results.CONCLUSIONS:Randomization to fostamatinib resulted in lower neutrophil counts and levels of circulating biomarkers in hospitalized patients with COVID-19; however, the observed impact of fostamatinib was modest compared with prior studies.

To exploit the electron-sponge properties of polyoxometalates (POMs) and elucidate the mechanistic impact of doping with saturated versus metal-substituted Dawson-type POMs on electrocatalytic CO2 reduction, P2W18@PCN-222 and P2W17M@PCN-222 (M = Co, Mn, Ni) composites were prepared using an impregnation method. Electrochemical analyses, in situ infrared spectroscopy, and DFT calculations reveal that substituted P2W17M clusters lower the free energy barriers for *COOH and *CO formation, promoting CO evolution. Specifically, P2W17Co acts as an electron donor, facilitating the directional transfer of electrons from the POM to the porphyrin active centers of the PCN-222. Consequently, P2W17Co@PCN-222 exhibits superior CO2 reduction reaction (CO2RR) performance, achieving a Faradaic efficiency for CO (FECO) of 82% and a partial current density (jCO) of 3.4 mA cm-2 at -0.80 V vs RHE, an 11.9-fold and 34.1-fold enhancement over pristine PCN-222 (FECO = 6.9%, jCO = 0.1 mA cm-2), respectively. In contrast, the saturated P2W18 cluster failed to establish an effective electron transfer pathway with the porphyrin centers and did not reduce the energy barrier associated with the rate-determining step (*COOH formation), thus conferring no promotional effect on the CO2RR.

To evaluate the impact of international pooled procurement mechanisms, which are primarily represented by the United Nations Children ' s Fund (UNICEF) and the Pan American Health Organization (PAHO), on the procurement prices of vaccines. Based on 14 497 vaccine procurement transaction records collected from 188 different countries spanning the period from 2013 to 2024, this research employed a high-dimensional fixed effects model along with an event study metho-dology to accurately identify the price effects and dynamic temporal trends, while simultaneously conducting a multidimensional heterogeneity analysis. (1) The baseline model demonstrated that, when compared to the independent self-procurement conducted by individual nations, utilizing pooled procurement through the UNICEF significantly reduced the average vaccine prices by 27.6% (β=-0.323, P < 0.01). The PAHO mechanism similarly exhibited an initial price reduction potential of approximately 30.9% (β=-0.370, P=0.052). (2) The event study method strictly validated the parallel trend assumption (joint significance test of pre-treatment coefficients: F=0.27, P=0.845). Dynamic tracking revealed that a price reduction of approximately 30.0% (β=-0.356, P < 0.01) was achieved exactly in the year of transitioning from self-procurement to pooled procurement, and this reduction effect remained persistently stable in subsequent years. (3) Heterogeneity tests revealed a significant "pro-poor" effect of pooled procurement: the price reduction margin obtained by small-scale buyers (38.5%, β=-0.487, P < 0.01) was significantly higher than that of large-scale buyers (22.5%, β=-0.255, P < 0.01). The marginal price reduction coefficient for non-Global Alliance for Vaccines and Immunization (GAVI) eligible countries (β=-0.418, P < 0.01) was substantially larger than that for GAVI eligible countries (β=-0.118, P < 0.05). The high-income country group experienced the most substantial price drop (β=-0.475, P < 0.01). (4) The supply-side moderating effect analysis indicated that UNICEF' s collective bargaining power maintained robustness across diverse market structures, showing no statistically significant attenuation despite increases in market concentration (interaction term β=0.095, P>0.10). Institutionalized pooled procurement mechanisms are capable of significantly reducing vaccine prices. For those countries that are currently in the immunization financing transition period, as well as those facing high self-procurement benchmark prices, participating in an efficient international pooled procurement platform serves as a critical institutional arrangement to replace external financial aid and to effectively maintain the long-term affordability of vaccines.

The use of carbon fiber prepreg composites offers a superior material solution, the efficiency of the production process using conventional methods is often constrained by very long curing times. Therefore, this study aims to analyze the effect of heating rate variations in the Rapid Curing (RC) method on the mechanical and physical properties of carbon fiber prepreg composites for prosthetic foot applications. The fabrication process was carried out using the Out-of-Autoclave (OoA) method with the Vacuum Bag Only (VBO) technique at heating rate variations of 1.5°C/min, 3°C/min, and 5°C/min. The fabricated specimens were evaluated through a series of mechanical tests, including tensile, bending, and impact tests, as well as physical tests consisting of density and porosity measurements. A heating rate of 3°C/min produced the best composite performance, evidenced by the lowest porosity, highest density, and improved tensile, flexural, and impact strengths compared to specimens prepared at other heating rates.

ABSTRACTDuodenal self‐expandable metal stents (SEMS) are widely used to treat malignant gastric outlet obstruction (GOO). However, stent migration is a well‐known complication. We report a rare case of small‐bowel impaction caused by the migration of a duodenal SEMS with a biliary plastic stent (PS). A 78‐year‐old woman with pancreatic head cancer underwent biliary PS and duodenal SEMS placement for obstructive jaundice and GOO. At 4 months after initiating neoadjuvant chemotherapy, computed tomography revealed tumor shrinkage and improvement in duodenal stenosis; however, the SEMS and PS had migrated to the ileum. Double‐balloon enteroscopy was attempted; however, stent removal was unsuccessful because of mechanical interlocking and impaction. Therefore, a partial ileal resection was performed. Histopathological examination revealed transmural infiltration of inflammatory cells and abscess formation. If a duodenal SEMS migrates with a biliary PS, mechanical interlocking may occur, resulting in small‐bowel impaction. Clinicians should be aware of this rare complication and should consider careful follow‐up and timely intervention if stent migration is detected.Trial Registration: N/A

This study proposes a data-driven experimental decision framework to identify the most suitable sustainable supplementary materials for green concrete, aiming to reduce cement usage, industrial waste burden, and environmental impacts in the construction sector. It experimentally evaluates compressive strength, split tensile strength, flexural strength, and ultrasonic pulse velocity (UPV) of green concrete incorporating waste materials including silica fume, GGBS, metakaolin, granite dust, rice husk ash, ceramic waste, marble powder, coconut shell powder, plastic waste, and bottom ash. A hybrid methodology integrating Pearson correlation, Analytical Hierarchy Process (AHP), and k-means clustering was developed to capture complex interrelationships. Correlation-based dependency analysis was incorporated into AHP to generate objective performance weightages, where compressive strength was ranked highest (37%), followed by flexural strength (25%), UPV (22%), and split tensile strength (16%). K-means clustering then categorized materials into best and worst performance groups. The findings revealed silica fume as the most optimal and balanced material, achieving 48.5MPa compressive strength, 4.0MPa split tensile strength, 7.5MPa flexural strength, and 4400m/s UPV, indicating superior structural performance and durability potential. ANOVA confirmed strong statistical distinction between clusters (p < 0.0001), validating the robustness of the classification. The main contribution of this work lies in introducing a scalable machine-learning-assisted multi-criteria framework that objectively ranks sustainable cement replacement materials, enabling reliable selection for high-performance green concrete design.

Conventional musculoskeletal spine models often rely on deterministic kinematic constraints to estimate spinopelvic kinematics and kinetics, which can produce unrealistic intervertebral motions and loading patterns. Incorporating intervertebral stiffness in kinematic evaluations would improve physiological accuracy, particularly during lifting tasks where spinal loading is critical. We developed a stiffness-dependent kinematics estimation workflow that integrates nonlinear intervertebral stiffness within an optimal control formulation, enabling spinal motion to emerge from mechanical behaviour rather than prescribed kinematic constraints in full body musculoskeletal models. Eleven healthy participants performed trunk flexion, lateral bending, and axial rotation tasks, with and without lifting a load. Predicted kinematics and compressive forces were compared against a conventional constraints-driven approach. A single-subject dataset with biplanar radiography provided ground-truth validation of vertebral motions. The stiffness-dependent method generated smoother, more physiologically plausible motion distributions and consistently reduced lumbar compressive loading. Vertebral orientation and position errors were lower than with the constraints-driven approach, and compressive forces aligned with literature ranges. Nonlinear stiffness modelling yields more evenly distributed spinal kinematics and reduced lumbar loading, providing a physiologically grounded framework for spine biomechanics and injury prevention research.

Lithium-ion batteries (LIBs) are subject to mechanical abuse both in electric vehicles and consumer electronic applications when dropped, which can lead to capacity degradation even if the cells survive the impact. This study investigates the impact of mechanical damage on the electrochemical performance of LIBs, focusing on capacity retention and internal resistance changes. The batteries were subjected to dynamic mechanical impact using varying impact energies (3J, 5J, and 7J) while measuring internal resistance and capacity before and after the impact. Hybrid Pulse Power Characterization (HPPC) was employed to assess internal resistance and capacity degradation across multiple cycles. Our results demonstrate that even minor mechanical damage can cause significant performance decay, especially after several cycles. The study also reveals that the state of charge (SOC) prior to impact has a minimal effect on the survival rate of the cells but influences the extent of damage observed. Post-impact analysis using optical microscopy indicates structural damage, including separator tears and delamination, contributing to capacity fade. This work highlights the importance of considering intermediate mechanical damage in LIB safety and performance assessments.

Impact of donor mechanism of injury on donation after circulatory death heart transplant outcomes: An analysis of the UNOS National Registry.

Having an inherent assembling ability, modular mechanical metamaterials can reconfigure geometry and adjust real-time performance. However, the unstable mechanical strength and limited local space flexibility of current assembly strategies impede the functional advancement of modular metamaterials, which lack intelligent solutions for on-demand reconfigurable environmental adaptation. Here, a novel self-locking assembly strategy is introduced, utilizing the coupling of positive and negative Poisson's ratios, enabling modular metamaterials to modify the structural deformation modes in confined spaces. Without volume expansion, it achieves controllable mechanical properties with 116% elastic stiffness adjustment, 189% stress strength change, and over 30% variation in energy absorption. Significantly, the self-locking mechanism improves stability in multi-layer configurations, surpassing current modular metamaterials by reducing overall stress fluctuations by up to 62.1% and nearly doubling the stability of local stress plateaus. Building on the evolution of mechanical properties and impact resistance, an enhanced KAN-LSTM model is developed to predict dynamic responses, with a specific focus on incorporating the assembly sequence. Despite the limited dataset, the model demonstrates excellent performance in fitting nonlinear impact responses and controlling average error. Compared to the original model, it improves nonlinear curve fitting on the test dataset within the sampled design space, reducing RMSE and MAE by approximately 20%. Additionally, post-experiment disassembly confirmed the excellent economic maintenance afforded by the modular strategy, with an average component recyclability of approximately 60.33%. Overall, this study offers a promising blueprint for reconfigurable modular core structural carriers in real-time perception and protection systems, with potential applications in port engineering, aerospace, and intelligent factories.

Meiosis is a key stage in the sexual reproduction of eukaryotes. It ensures the continuity of genetic information from generation to generation, while also generating the necessary genetic diversity for the survival and evolution of species. Meiotic progression is often compromised in hybrids between related subspecies, resulting in hybrid sterility and irreversible reproductive isolation. However, most genetic studies to date have not focused on the meiotic phenotypes of hybrid sterility and their molecular mechanisms. This review examines the genetic architecture, as well as the meiotic and molecular phenotypes, of hybrid sterility in the house mouse (Mus musculus) and other mammals. House mice subspecies provide the most widely understood mammalian model of hybrid sterility because of their recent evolutionary divergence, powerful genetic tools and comprehensive cytology of individual meiotic stages. We emphasize the potential impact of meiotic surveillance mechanisms, checkpoint pathways, particularly those leading to the meiotic sex chromosome inactivation and we draw parallels between intraspecific genic and chromosomal sterility and intersubspecific hybrid sterility. Finally, we review the Prdm9-Mir465 incompatibility system, the only vertebrate hybrid sterility model for which the three major genetic components necessary and sufficient to recreate the hybrid sterility genome have been identified. This three-part genetic architecture links Prdm9-dependent meiotic recombination hotspot activation, heterosubspecific homolog pairing, and microRNA-mediated meiotic checkpoint regulation to spermatogenic arrest and male sterility. MiR-465 is apparently the first microRNA which functions as a guardian of the pachytene checkpoint.

For precision assembly tasks, the accuracy and efficiency of robotic arm trajectory planning directly impact product quality and production efficiency in manufacturing, making it a core technology driving industrial automation upgrades. This research endeavors to establish a sophisticated multi-objective trajectory planning model, specifically engineered to cater to the intricate demands of precision assembly scenarios. The model optimizes for "maximum efficiency, minimum energy consumption, and minimal impact," quantifying time costs, energy expenditure, and the influence of mechanical impact on assembly precision during the process. To enhance the performance of traditional multi-objective particle swarm optimization (MOPSO), this study proposes an improved CEMOPSO algorithm. This approach enhances initial population diversity by incorporating Chebyshev mapping strategies, dynamically adjusts particle search directions through evolutionary elimination mechanisms, and optimizes constraint handling capabilities via a designed infeasibility evaluation function. Engineering experiments using pyrotechnic grain assembly as a typical scenario validate CEMOPSO's practical application value. Implementing this algorithm increased robotic arm assembly efficiency by 15.2%, reduced energy consumption by 20.4%, and decreased impact by 26.4%. This demonstrates the effectiveness and engineering applicability of the theoretical methods developed in this study for complex precision assembly tasks.

ABSTRACT This study systematically investigates the synergistic effects of poplar wood flour and silica nanoparticles on the mechanical and thermal properties of polypropylene-(PP)-based wood-plastic composites (WPCs). While these materials are widely used in structural and semi-structural applications, maintaining a balance between mechanical stiffness, impact resistance, and thermal stability at high filler loadings often presents a practical challenge. To address this, the current work aims to optimize this dual-filler system to overcome such limitations. Composites were fabricated with wood flour contents of 30, 40, and 50 wt.% and nanosilica loadings of 0, 1, 3, and 5 wt.%, using 2 wt.% maleic anhydride-grafted polypropylene (MAPP) as a compatibilizer. Results showed that increasing wood flour content significantly enhanced tensile and flexural stiffness and strength but reduced impact resistance due to increased brittleness. The incorporation of nanosilica up to 3 wt.% further improved tensile and flexural properties; however, agglomeration at 5 wt.% diminished these gains. Finite element simulations conducted in Abaqus predicted the mechanical behavior and validated experimental trends, offering insights into stress distribution and failure mechanisms. The results demonstrate that tailoring the dual-filler composition enables the optimization of WPCs for targeted applications, balancing mechanical strength, impact resistance, and fire safety.

Glycosylation stabilizes TNFα and receptor complexes: structural and biophysical implications.

Examining the impact of GLUT4 protein molecular mechanism on skeletal muscle exercise metabolism through electrochemical sensors: Role of protein macromolecules

This study tests materials by additive manufacturing methods that will demonstrate impact resistance and structural stability comparable to conventional EVA. Researchers tested ethylene-vinyl acetate copolymers, thermoplastic polyurethane via fused deposition modeling, and flexible photopolymer resins from liquid crystal display-based three-dimensional printing. Analyses included tensile strength, hardness, and impact resistance. Thermoplastic Polyurethane via fused deposition modeling showed the best combination of elasticity, energy dissipation, and durability. Ethylene-vinyl acetate exhibited lower resilience, and the resins failed prematurely. Increased thickness and structural reinforcement improved protection. The material manufacturing method and design significantly influence a mouthguard's effectiveness. Thermoplastic Polyurethane made with additive manufacturing, especially with reinforced designs, offers superior resilience for high-impact sports, providing a path for customizable, effective, and accessible preventive dentistry.

The afferent (ascending) auditory system and how its specialized mechanisms and circuits support ecologically relevant auditory computations such as speech recognition have received considerable attention in decades past. This work has culminated in accurate computational models of early afferent coding alongside a good understanding of how low-level mechanisms (e.g., peripheral tuning) impact auditory perception. In contrast, the auditory efferent (descending) system and its role in auditory perception are much less well understood. To address this gap in knowledge, we describe modifications to a model of the auditory periphery to include the medial olivocochlear efferent reflex pathway. Neurons in this pathway respond to sound and make descending projections to outer hair cells that reduce cochlear gain in a reflex-like loop. Our model of this system differs from existing models primarily in its multichannel design, which is intended to simulate the consequences of tonotopically distributed control of outer hair cells by individual medial olivocochlear neurons. We show that this model can simulate the frequency-specific sensitivity and strength of the effects of contralateral elicitors on auditory-nerve responses, including especially the effect of elicitors that are tonotopically distant from probes.