Search Results (1,640)

Aluminum metallic foams are lightweight porous materials characterized by low density, high stiffness, and remarkable energy absorption capacity. The mechanical performance of these materials strongly depends on the microstructure of the metallic matrix and the porous structure. In this study, closed-cell A356 aluminum foams were produced by the Alporas melt-foaming method using barite (BaSO₄) as a thickening agent and calcium carbonate (CaCO₃) as a foaming agent. The effect of grain refinement on the microstructure and energy absorption behavior under quasi-static compression was investigated. Grain refinement was evaluated by adding four concentrations of Al-5Ti-1B master alloy (0.02, 0.05, 0.08, and 0.10 wt.%) to the unrefined foam. The addition of Al-5Ti-1B reduced the secondary dendrite arm spacing (SDAS) from 41.85 µm to a minimum of 32.96 µm at 0.05 wt.%, producing stronger and more homogeneous cell walls that increased the plateau stress from 0.525 to 1.549 MPa and the energy absorption capacity from 0.299 to 0.735 MJ/m³—improvements of 195% and 145%, respectively. The energy absorption efficiency analysis confirmed that any refiner concentration improved the compressive performance compared to the unrefined foam. In addition, the energy absorption efficiency (E) and the ideality energy absorption efficiency (I) confirm that the refinement of the dendritic structure through Al-5Ti-1B addition strengthens the foam cell walls, improving their mechanical behavior and performance as an energy-absorbing material under quasi-static compression. Full article

This study proposes an integrated finite element methodology for evaluating and redesigning three critical subsystems of an XCMG XC740K skid-steer loader: the excavation attachment, the arm–bucket charging system, and the ROPS/FOPS operator protection cab. The components were reconstructed by reverse engineering and 3D scanning, modeled in CAD, and simulated in ANSYS Workbench/Mechanical under load cases derived from hydraulic parameters, soil–tool interaction, and international safety standards. The novelty of the work lies in applying a single FEM-based workflow to three interacting subsystems of the same compact machine, rather than optimizing isolated components independently. The original configuration showed critical effort concentrations in the cab and charging system. Localized geometric reinforcements and the use of high-strength and wear-resistant steels improved stiffness and safety margins in the excavation bucket, loading bucket, and ROPS/FOPS cab. However, the arm–quick coupler region remained the controlling weak point of the loading assembly, indicating the need for further redesign. The proposed approach provides a transferable computational framework for identifying structural vulnerabilities and prioritizing redesign actions in compact earthmoving machinery. Because the study is numerical, future experimental validation is required before certification or field implementation. Full article

Reliable hand gesture recognition (HGR) using wearable sensors remains challenging due to variability in arm posture, motion, and individual muscle activation patterns. To facilitate systematic investigation of multi-modal sensing strategies under realistic operating conditions, this paper presents a comprehensive dataset of surface electromyography (sEMG) and pressure-based force myography (pFMG) signals. The dataset includes three complementary subsets acquired under controlled static arm posture, multiple static arm postures, and combined static and dynamic arm postures. Signals were recorded using a custom-designed co-located sEMG-pFMG armband, enabling the simultaneous capture of electrical muscle activation and mechanical muscle deformation. System validation is conducted from three perspectives. First, hardware-level signal quality is assessed through signal-to-noise ratio (SNR) analysis across all gestures and sensing channels, demonstrating stable and reliable signal acquisition. Second, representative raw waveform examples are provided to qualitatively illustrate modality-specific and condition-dependent signal characteristics under static and dynamic arm-posture scenarios. Third, reproducible baseline gesture recognition experiments are performed using conventional machine learning classifiers. By providing multi-modal data acquired under both static and dynamic arm-posture conditions, along with clearly de-fined experimental protocols and baseline benchmarks, this dataset serves as a valuable resource for developing, evaluating, and comparing gesture recognition algorithms and arm-wearable human–machine interface (HMI) systems. Full article

As Large Language Models (LLMs) increasingly operate in agentic environments communicating via the Model Context Protocol (MCP), the structured JSON-RPC message traffic is growing rapidly. Yet the current MCP specification does not include any compression mechanism, leaving potential bandwidth optimizations unaddressed. This paper presents the first empirical energy measurement study of lossless compression applied to MCP payloads on embedded ARM hardware. Four production codecs are evaluated at a single, consistent real-time operating point per codec (LZ4 L0, Zstd L3, gzip L6, Brotli Q4). Across two different datasets, our results show that compression is counterproductive below approximately 50–200 bytes depending on the codec, while savings of up to 50% are achievable for larger payloads. Brotli achieves the highest compression ratio (49.9% combined savings) but incurs the greatest CPU and energy cost. Zstd offers the best practical trade-off, delivering approximately 47% bandwidth reduction with low overhead. Message size is the dominant predictor: below a per-codec break-even of approx. 200 B for LZ4, compression expands rather than shrinks the payload. The apparent per-message-type penalties reflect the prevalence of short messages, not the codec. Message size is identified as the primary predictor of compression benefit, and codec selection guidelines are provided for latency-critical, general-purpose, and bandwidth-constrained MCP deployments on resource-constrained devices. Full article

The human APOBEC3 (A3) family of cytidine deaminases, including A3G, A3F, and A3H, participates in cellular anti-retroviral immunity. In contrast, to antagonize the anti-retroviral activities of these A3 family proteins, HIV-1 produces its gene product called viral infectivity factor (Vif) in infected cells. Vif is a pleiotropic hub protein that specifically binds to various A3 proteins with the aid of host core-binding factor subunit β (CBF-β) and mediates their proteasomal degradation. To date, numerous biological and structural studies have been performed to understand the arms race between A3 and Vif. Previous extensive mutagenesis and structural analyses have suggested that there are three distinct types of Vif-binding interfaces among human A3s and three largely nonoverlapping interfaces on Vif for binding with these A3s. Moreover, recent cryo-electron microscopy (cryo-EM) structural analyses have clarified further details of the different intermolecular interactions of Vif with each of three human A3s (A3G, A3F, and A3H) and have proposed a possible mechanism by which one Vif molecule can recognize all three types of A3s. In this review, we summarize the current understanding of the structural basis of the interaction between A3 and Vif. This information may be helpful for developing drugs targeting these interfaces. Full article

The countermovement jump (CMJ) is a common measure of lower-body power and neuromuscular performance. Incorporating an arm swing (AS) enhances CMJ outcomes, yet the contributions of anthropometrics, body composition (BC), and muscular power to performance are not fully understood in recreationally active adults. This study examined these factors in CMJ trials with and without AS. Thirty adults (15 males, 15 females; 18–25 years) performed CMJs on a force plate. Upper-body power was assessed via an 8 kg medicine ball throw, and lower-body power using a maximal cycling-based power test. Three-dimensional body scanning captured anthropometric data. Descriptive statistics, Pearson correlations, and hierarchical multiple regressions were conducted for the total sample and by sex. Jump height and peak power were significantly greater with AS than without (p < 0.001). Strong positive correlations were observed among jump- and power-related variables (r = 0.73–0.92). Body fat percentage showed moderate-to-strong negative associations with relative peak power, particularly in females. Regression analyses revealed that BC accounted for the largest proportion of variance in AS Peak Power, whereas upper-body power did not provide additional predictive value beyond anthropometrics and BC. These findings indicate that CMJ performance may be influenced primarily by lower-body mechanical capacity and BC, with adiposity consistently reducing relative power output. The results underscore the importance of BC in explosive performance training and support the use of AS-restricted jumps to isolate lower-body power during performance assessments. Full article

There are several forms of monoallelic expression, in which the 50:50 ratio in the expression activity of each of the two copies of the gene is disrupted. This review focuses on the phenomenon of random autosomal monoallelic expression (aRME), a process in which only one of the two alleles is transcribed in a single cell, and the allele choice is not determined by the parental origin. One of the central problems in studying this phenomenon is the differentiation of the two forms of aRME: clonal, in which the expression pattern is mitotically inherited, and stochastic, when the allele choice can change over time due to transcriptional bursting. Distinguishing these events is methodologically challenging: divergent experimental approaches and the lack of standardized detection criteria have produced strikingly contradictory estimates of aRME prevalence. Furthermore, single-cell transcriptomic approaches are particularly susceptible to technical artefacts that can generate false-positive monoallelic calls, complicating the distinction between heritable and transient states. In this review, we critically evaluate the evidence for clonal and stochastic aRME, examine the epigenetic mechanisms proposed to maintain monoallelic expression, and discuss its clinical significance, focusing on the role of monoallelic expression in the penetrance of autosomal dominant diseases (including congenital immune disorders and cardiomyopathy), neurodevelopmental disorders, and cancer progression. Full article

To address the limitations of current Agaricus bisporus harvesting robots, including low picking efficiency, susceptibility to mechanical damage, poor operational stability, and discontinuous harvesting processes, an integrated robotic system capable of mushroom detection and localization, picking sequence planning, stipe-cutting, and grading was developed. The robot adopts a left-right symmetrical configuration and operates along the side of the mushroom cultivation racks. It mainly consists of a mobile platform, a lifting mechanism, dual picking units, a receiving unit, a stipe-cutting device, a collection system, and an electronic control system. A picking sequence planning method based on YOLOv8n-USD and KD-tree nearest neighbor search was employed to determine the optimal harvesting order for densely clustered and adhered mushrooms. The dual robotic arms executed the picking operations, after which the mushrooms were transferred to the receiving unit for stipe-cutting and subsequently classified according to the detection results, thereby completing the integrated process of detection, picking, stipe-cutting, and grading. Experimental results show that the average detection accuracy reaches 96.64%, the picking success rate is 95.39%, and the harvesting damage rate is 1.63%, while the average interaction failure rate and grading error rate are 0.35% and 1.28%, respectively. These results indicate that the proposed robot can achieve accurate detection and efficient integrated operation for densely clustered Agaricus bisporus. The findings provide a reference for flexible and efficient harvesting of Agaricus bisporus with synchronized stipe-cutting and grading operations. Full article

Given the lack of clinical data supporting the effects of a novel guava jelly drink on cognition and mood regulation, we aimed to explore these effects and their possible mechanisms in working-age volunteers. In an 8-week, three-arm double-blind, placebo-controlled trial, healthy males and females aged 20–40 years old (N = 25/arm) were randomly assigned to consume 86 g per day of either a placebo or guava jelly drink containing either a low (36.6%) or high (73.2%) dose of guava juice with mint syrup. N100 and P300 brain waves, working memory, Perceived Stress Scale (PSS), Hospital Anxiety and Depression Scale (HADS), and biomarkers related to oxidative stress, inflammation, neurotransmitters, and gut microbiota were assessed at baseline and after 4 and 8 weeks of consumption. The low-dose group showed improvements in N100 amplitude, P300 latency, and HADS anxiety score, whereas the high-dose group exhibited improved N100 amplitude, working memory, PSS score, and total HADS score. In addition, the high-dose group also exhibited increased GPx activity without a reduction in MDA. Overall, these results suggest that guava jelly drink positively modulates perceived stress, anxiety, selective attention, and working memory. However, the precise underlying mechanism requires further study. Full article

The ubiquitin–proteasome system (UPS) has traditionally been described as a tightly regulated degradative network driven mainly by the specificity of its ubiquitin-conjugating enzymatic components. The 26S proteasome is the catalytic arm of the system that acts downstream to the conjugation machinery. For a long time, it has been considered to be a constitutive multi-subunit proteolytic complex that recognizes in a non-discriminatory manner ubiquitin-marked target substrates with less than a handful of exceptions. However, emerging evidence reveals that the 26S proteasome function is also dynamically regulated by multiple factors, such as subunit composition and synthesis, post-translational modifications, and spatial localization, all of which are tightly regulated by the metabolic and stress states of the cell. Importantly, dysregulation of these newly emerging regulatory mechanisms has pathogenic sequelae. These mechanisms fine-tune proteasome activity and expand its role as an active regulator of protein homeostasis rather than being a passive degradation machinery. Given the rapid expansion of these findings and their impact on our understanding of proteasome biology, an integrated overview of these regulatory mechanisms is timely. Full article

Hamstring injuries in professional baseball remain incompletely understood related to laterality in being either ipsilateral or contralateral to the throwing arm. General and specific injury comparisons were investigated with respect to independent lower-limb, environmental conditions, position, throwing arm side relationship, and age. More left and non-dominant-sided hamstring injuries were hypothesized in baserunning with greater injury presence in infielders and younger players. Between 2011 and 2017, 1435 hamstring injuries were identified within the major league baseball Health and Injury Tracking System. Data included laterality (left versus right, contralateral versus ipsilateral to the throwing arm), position, time of season, days missed, mechanism of injury, and age. Chi-Square, t-tests and Mann–Whitney U tests evaluated significant findings with an a priori of p < 0.05. No significant differences in injury laterality (right vs. left) with baserunning (p = 0.797) or in total (p = 0.367) or contralateral vs. ipsilateral injury laterality in total (p = 0.770) were seen. No significant laterality differences were seen by position, days missed, or time in the season. In general, most injuries occurred in the first half of the season (67.8%, 973/1435). Outfielders were the most injured position (34%, 495/1435). Athletes under 25 years were the most injured age group as compared to the 30–34 group (p = 0.037), 35–39 group (p = 0.038), and the 40+ group (p = 0.024). No statistically significant hamstring injury asymmetries were identified among major league baseball players despite biomechanical theories suggesting potential differences in lower-limb loading during baseball activities. Younger athletes demonstrated greater injury susceptibility, highlighting the need for future investigation into factors that may contribute to elevated injury incidence in younger professional baseball players. Full article

Salmonella is a globally significant foodborne intracellular pathogen, and invasive salmonellosis poses a major global public health threat. The NLR family CARD-containing protein 4 (NLRC4) inflammasome, a pivotal cytosolic innate immune sensor, specifically recognizes Salmonella flagellin and type III secretion system (T3SS) components via the NAIP (NLR family apoptosis inhibitory protein) family. Upon activation, it triggers pyroptosis, pro-inflammatory cytokine release, and infected intestinal epithelial cell extrusion, serving as a central pathway for host defense against Salmonella colonization and systemic spread. This work systematically summarizes the structural composition, activation mechanisms, post-translational modifications, and regulatory protein network of the NLRC4 inflammasome, and highlights the molecular mechanisms by which Salmonella evades NLRC4 surveillance through multiple strategies: transcriptional downregulation of immunogenic ligands, structural modification of T3SS components, secretion of effector proteins, and chemotaxis-virulence synergy. A comprehensive delineation of the co-evolutionary arms race between Salmonella and the NLRC4 inflammasome provides an integrated mechanistic framework for understanding host–pathogen immune interplay. Deciphering the mechanisms of bacterial immune evasion on this basis holds critical importance for identifying novel anti-infective targets and advancing translational preventive and therapeutic strategies against salmonellosis. Full article

Teleoperated dual-arm underwater manipulators are a promising alternative to divers for hazardous subsea tasks, such as removing fishing nets from ship propellers. However, kinematic discrepancies between the master and slave can cause self-collisions between links that the operator cannot perceive, risking mechanical damage and costly underwater recovery. Real-time self-collision detection is therefore essential, yet existing approaches face an accuracy–efficiency trade-off: mesh-based methods such as GJK and FCL are accurate but computationally costly, while sphere and capsule approximations overestimate distances near joint interfaces, causing false positives. This paper proposes the Generatrix Distance Method (GDM), an analytical algorithm with bounded $\mathcal{O}\left(1\right)$ per-pair complexity for real-time self-collision detection. GDM approximates each link as a finite-length cylinder and classifies the configuration between two cylinders into four cases: Side–Side, Side–Cap, Cap–Side, and Cap–Cap. The Side–Side case admits a closed-form solution; cap-involved cases use a bounded-iteration cap-edge projection. Cylinder parameters are systematically derived from URDF kinematic information, enabling platform-independent deployment. GDM was validated through Gazebo simulations of a dual-arm underwater walking robot and teleoperation experiments on the ROBOTIS FFW-SG2 AI Worker. GDM runs about $10\times$ faster than FCL-Cylinder, while its iterative variant attains a 0.15 mm mean error at a $3\times$ speedup, confirming real-time suitability. Full article

Background/Objectives: Children with adenotonsillar hypertrophy (ATH) and sleep-disordered breathing (SDB) may have altered body composition. The roles of anatomical upper airway obstruction and functional respiratory impairment in the risk of body composition remain poorly understood. This study assessed nutritional status in children. It also examined how nasopharyngeal obstruction (NP) due to ATH and SDB symptoms affects adiposity and fat distribution. Methods: This cross-sectional study included 106 children (57 boys, 49 girls; mean age 6.1 ± 2.0 years) who were scheduled for surgical treatment. Flexible nasopharyngolaryngoscopy was used to measure the size of the adenoid and palatine tonsils and combined grades of adenoid and tonsillar hypertrophy were used to determine NP obstruction. Parents filled out a questionnaire to assess SDB symptoms. Anthropometric measures (height, weight, BMI, skinfold thicknesses, body circumferences) were expressed as age- and sex-standardised scores. General linear models (GLMs) were used to examine associations between disease factors and body composition. Results: About 21% of participants were classified as overweight or obese. In contrast, 10% were undernourished. Severe NP obstruction was present in 57% of children. SDB symptoms appeared in 28% of children. Despite normal linear growth, children with ATH showed greater adiposity than reference values. In univariate analyses, severe NP obstruction was associated with higher body weight, BMI, triceps and subscapular skinfold thicknesses, waist circumference, and waist-to-height ratio (WHtR). However, after adjustment for BMI, these associations were no longer significant. In contrast, SDB symptoms were independently associated with increased subcutaneous adiposity, as indicated by greater subscapular and abdominal skinfold thicknesses, greater mid-upper arm fat area, and higher WHtR. The pattern showed a more central distribution of fat. Conclusion: Children with ATH and SDB symptoms reported by a parent had increased subcutaneous and central adiposity, independent of BMI or the anatomical severity of nasopharyngeal obstruction. Longitudinal studies incorporating objective assessment of SDB are warranted to further clarify the mechanisms underlying these associations. Full article

This paper proposes a high-sensitivity and sensitivity-tunable vibration sensing system based on a switchable loop length optoelectronic oscillator (OEO). Carrier-sideband separation is realized by using an acousto-optic modulator (AOM), and the resonant cavity length is designed to be independent of the sensing fiber arm. Compared with a conventional 10 GHz OEO under the same total loop delay condition, the proposed architecture provides a theoretical sensitivity enhancement of approximately $1.93\times {10}^4$, without requiring a high RF oscillation frequency. Meanwhile, the system oscillates at only 80 MHz, which greatly reduces the implementation difficulty of the frequency detection circuit. The proposed scheme further introduces a mechanical optical switch (MOS) to select intra-loop fibers of different lengths, thereby reconfiguring the equivalent loop delay and the free spectral range of the OEO. Experimental results show that stable single-mode oscillation is achieved at 80.42 MHz with a side-mode suppression ratio of 51 dB. By selecting loop fiber lengths of 1200 m, 500 m and 0 m, frequency-to-displacement sensitivities of 0.892 GHz/cm, 1.93 GHz/cm and 9.27 GHz/cm are obtained respectively, with excellent linearity. A 600 Hz vibration signal is successfully demodulated with a signal-to-noise ratio of 72.1 dB. The proposed method provides a simple and reconfigurable solution for high-precision vibration measurement under different operating conditions. Full article