Hong Kong University of Science and Technology
Hong Kong University of Science and Technology Institutional RepositoryNot a member yet
162821 research outputs found
Sort by
Motion sickness: multiple linear regression identifies behaviours linked to motion-induced emesis in Suncus murinus (house musk shrew)
No full textMotion sickness (MS) is a complex syndrome characterized by a spectrum of autonomic and behavioural symptoms, often accompanied by emesis. Suncus murinus has become a primary species in which to study the mechanisms of emesis control, yet the behavioural profile associated with motion-induced malaise of this animal has not been thoroughly assessed. In this study, we exposed 129 animals to provocative motion (1 Hz, 4-cm horizontal reciprocating displacement, 30 min) to induce MS and systematically recorded spontaneous behaviours, retching and/or vomiting (R/V), and changes in body surface and tail temperatures. A non-biased MS symptom score was developed based on stepwise multiple linear regression, incorporating nine observable behaviours and physiological variables, namely scratching, stretching, chin on the floor, burrowing, chewing the bedding, micturition, defecation and/or tenesmus, remaining stationary, and body surface and tail temperature changes. Administration of two anti-MS drugs, diphenhydramine (30 mg/kg, s.c.) and scopolamine (10 mg/kg, s.c.), significantly reduced the MS symptom score from 14.25 ± 1.89 to 7.84 ± 0.85 and from 18.11 ± 2.28 to 11.91 ± 0.87 respectively, indicating the validity of the scoring system as a quantitative measure of motion-induced ‘sickness’, ‘malaise’, and even ‘nausea’ in this species. Shapley additive explanation (SHAP) analysis further indicated the contributions of two individual spontaneous behaviours, stationary duration and chin on the floor episode, to MS prediction. Our findings suggest that this behavioural scoring system provides a reliable and translationally relevant tool for studying MS and screening potential anti-emetic treatments for humans.</p
A Si-MoSe2 Heterostructured Anode with Enhanced Thermal Transport and Electrochemical Performance for Liquid and All-Solid-State Lithium-Ion Batteries
No full textSilicon anodes offer high theoretical capacity for lithium-ion batteries but suffer from volume-change-induced instability and degradation. Conventional van der Waals coatings yield unstable interfaces and poor ion/electron transport, while thermal transport remains underexplored. Here, we propose heterointerface-engineered Si@MoSe2@C anodes with chemically bonded interfaces, where lattice-matched MoSe2 covalently bridges porous Si and carbon coating, forming robust Si─Se─Mo linkages that stabilize the structure and optimize transport pathways. The Si@MoSe2@C anode delivers 1054 mAh g?1 after 100 cycles at 0.2 A g?1?exceeding most Si anodes?and 99.5% Coulombic efficiency over 400 cycles at 1.0 A g?1, with high cycling efficiency demonstrated in both liquid and all-solid-state lithium-ion batteries (ASSLIBs). In situ X-ray diffraction, Raman spectroscopy, and electron microscopy/spectroscopy, together with first-principles calculations, confirm that this MoSe2-mediated covalent bridging enables reversible reactions with favorable kinetics and structural integrity by strengthening and delocalizing Se─Si bonding and reducing Li+ migration barriers by 24%. Critically, we present the first measurements of the effective thermal conductivity of a silicon-anode composite, showing that Si@MoSe2@C exhibits a 27% higher value than Si, addressing long-overlooked cell-level thermal-management requirements and improving elevated-temperature cell performance. This heterointerface design provides a synergistic strategy for engineering high-performance Si anodes across batteries with enhanced safety
Dual-horizon peridynamic modeling of thermally induced fracture in anisotropic materials: A variational energy-based approach
No full textFracturing phenomena driven by temperature variations present substantial challenges across geotechnical engineering applications. Accurate computational representation of such behavior demands robust numerical architectures that can reliably capture discontinuous crack evolution within materials characterized by pronounced directional dependencies. This paper introduces a novel approach that integrates dual-horizon non-ordinary state-based peridynamics (DH-NOSBPD) with a variational damage model for simulating thermo-mechanical fracture in anisotropic media. The proposed framework overcomes the limitations of conventional peridynamic methods in representing anisotropic thermal and mechanical coupling while eliminating numerical instabilities inherent in bond-breaking criteria. A staggered coupling strategy is employed to synchronize thermal and mechanical field updates, incorporating anisotropic constitutive relationships for both heat conduction and stress–strain behavior. The variational damage model introduces a history-dependent scalar damage field derived from strain energy density, thereby circumventing the spurious energy release and mesh dependence associated with abrupt bond deletion. This approach yields physically consistent crack evolution. Numerical examples validate the framework's accuracy in anisotropic heat transfer, mechanical deformation, and complex fracture patterns under combined thermo-mechanical loading. The model demonstrates superior stability and predictive capability compared to conventional bond-breaking approaches.</p
UltraMamba: Mamba-based Multimodal Ultrasound Image Adaptive Fusion for Breast Lesion Segmentation
No full textMultimodal ultrasound imaging, combining B-mode ultrasound, shear wave velocity, and shear wave time, is crucial for diagnosing and treating breast lesions, providing insights into lesion characteristics and tissue properties. However, challenges arise from intermodal feature misalignment and attention shifts due to varied capture methods and an overemphasis on vibrant color data. To tackle these issues, we introduce two innovations: a novel segmentation framework and a comprehensive dataset. The UltraMamba framework utilizes bidirectional alignment between modalities and enhances region-specific information to improve breast lesion segmentation accuracy. Key components include the Cross-Modal Knowledge Interaction module for robust information exchange and the Region-Aware Feature Excitation module to focus on relevant features. We also present the BreLS dataset, the first two-dimensional multimodal ultrasound breast lesion dataset, with paired images from 506 cases, serving as a valuable resource for analysis. UltraMamba shows strong performance on the BreLS dataset, achieving a Dice Similarity Coefficient of 72.16% and an HD95 of 42.02 mm, reflecting improvements of 2.59% in DSC and a 6.78 mm reduction in HD95 compared to the second-best framework, MMCA-NET. These results highlight UltraMamba’s potential to enhance segmentation accuracy in clinical settings, facilitating precise treatment planning and, ultimately, leading to improved outcomes.</p
Strategic Decision-Making Under Uncertainty Through Bilevel Game Theory and Distributionally Robust Optimization
No full textIn strategic scenarios where decision-makers operate at different hierarchical levels, traditional optimization methods often fail to adequately handle uncertainties arising from incomplete information or unpredictable external factors. To fill this gap, we introduce a mathematical framework that integrates bilevel game theory with distributionally robust optimization (DRO), particularly suited for complex network systems. Our approach leverages the hierarchical structure of bilevel games to model leader–follower interactions while incorporating distributional robustness to guard against worst-case probability distributions. To ensure computational tractability, the Karush–Kuhn–Tucker (KKT) conditions are used to transform the bilevel challenge into a more manageable single-level model, and the infinite-dimensional DRO problem is reformulated into a finite equivalent. We propose a generalized algorithm to solve this integrated model. Simulation results validate our framework’s efficacy, demonstrating that under high uncertainty, the proposed model achieves up to a 22% cost reduction compared to traditional stochastic methods while maintaining a service level of over 90%. This highlights its potential to significantly improve decision quality and robustness in networked systems such as transportation and communication networks.</p
Stable calcium metal batteries enabled by ionic covalent organic framework artificial protection layers
No full textCalcium metal batteries (CMBs), utilizing calcium (Ca) as anodes, offer great potential for next-generation high-energy density battery technologies. However, Ca plating/stripping at room temperature (r.t.) is severely impeded by the formation of ion-insulating passivation layers. Constructing artificial protective layers that can effectively transport Ca2+ on Ca metal is crucial for realizing practical CMBs. Nonetheless, identifying a suitable candidate that is both highly ionic conductive (>10−4 S cm−1 at r.t.) and electrically insulating remains a formidable challenge. Ionic covalent organic frameworks (iCOFs) represent a distinctive class of porous, crystalline polymers containing ionic moieties to facilitate ion conduction in batteries. In this study, we introduce, for the first time, single-ion conductive sulfonate iCOFs with a Ca2+ transference number of 0.95 and ionic conductivity of 2.23 × 10−4 S cm−1 at r.t. as artificial protective layers for the Ca metal anode. This iCOF protective layer promotes uniform Ca deposition and effective anticorrosion of modified anodes. As a result, full cells equipped with iCOF-protective Ca anodes and polyaniline cathodes demonstrated stable operation up to 75 cycles with high energy density. Our work facilitates the attainment of high-performance CMBs by the construction of iCOF protective layers. (Figure presented.).</p
Self-Swerving Optical Force by Chiral Inhomogeneity
No full textLight exerts optical forces on objects, finding numerous applications in physical and biomedical sciences. It is commonly known that the direction of the optical force on a single sphere is dictated by the light field. Thus, actively switching light properties such as polarization is an efficient strategy to control the locomotion of particles. Here, by exploiting the reversible optical force induced by chiral inhomogeneity, we observe self-swerving behavior in a chiral sphere embedded in water via a linearly polarized light wave. This counterintuitive optical force, arising from Poynting momentum conservation in chiral light-matter interaction, reverses direction with variations in the chirality gradient, inducing a self-swerving effect as the particle rotates. Experimentally, we observe that chiral particles, ranging from nanometers to micrometers in size, exhibit self-swerving behavior under a fixed linear polarization. Our study delves into a novel realm of optical forces in the presence of ubiquitous imperfect or inhomogeneous materials. It enriches the understanding of chiral-light interactions, and facilitates diverse applications in chiral detection, advanced optical manipulation, and micro-robots.</p
Whole-Course-Repair Wound Dressing Based on Bovine Colostrum and Hyaluronic Acid for Diabetic Wound Repair Through Immunomodulation, Angiogenesis, and Re-Epithelization
No full textExcessive immune response, obstruction of angiogenesis, degradation of collagen deposition, and delayed re-epithelialization are the primary factors obstructing diabetic wound healing. Adequate and inclusive strategies are needed to address these challenges comprehensively. In this study, a whole-course-repair wound dressing (BC/HA) was simply fabricated to enhance diabetic wound closure. The BC/HA wound dressing, created by combining bovine colostrum (BC) with hyaluronic acid solution (HA), demonstrated good cytocompatibility, endothelial cell migration, angiogenesis, and antibiofilm effects. Using a full-thickness diabetic wound model, we found that the BC/HA dressing effectively modulated the diabetic wound microenvironment. Specifically, it facilitated the conversion of pro-inflammatory M1 macrophages to pro-regenerative M2 macrophages at a rate twice that of the control group. This transformation subsequently promoted endothelial cell migration to the wound sites during the inflammatory phase, resulting in over a 3.8-fold enhancement in vascular formation during the proliferation phase. Furthermore, the BC/HA wound dressing promoted re-epithelialization and facilitated the formation of dermal appendages, hair follicles, and glands in the remodeling phase. These findings shed light on the potential of the BC/HA wound dressing as a promising platform for chronic wound regeneration.</p
Source apportionment of fine and coarse particulate matter in Hong Kong and its implications to PM<sub>10</sub> air quality management
No full textEffective control of ambient respirable particulate matter (PM10, particles with aerodynamic diameters less than 10 μm) is essential for air quality management for public health protection. Achieving this requires targeted strategies that address both fine particles (PM2.5, less than 2.5 μm) and coarse particles (PMcoarse, between 2.5 and 10 μm). In this study, we conducted a two-year field monitoring campaign in an urban residential area in Hong Kong to simultaneously characterize the chemical compositions and sources of PM2.5 and PMcoarse. Nearly half (46 %) of PM10 mass was associated with PMcoarse, with individual species exhibiting distinct distribution patterns across the two size fractions. Transition metals known for their roles in PM oxidative potential (e.g., Mn and Cu) were found to be evenly distributed between fine and coarse modes, underscoring the need for further assessments of their size-resolved health effects. Source apportionment using positive matrix factorization showed that PM2.5 was mainly influenced by secondary sulfate and nitrate formation, road traffic and biomass/coal combustion, whereas PMcoarse was dominated by soil/industrial dust, construction/copper-rich dust and sea salt. Backward air mass trajectory analysis identified a 28 μg/m3 increase in PM10 source contribution under continental air mass influences compared to marine air masses. Coarse-mode soil and industrial dust, primarily transported from inner-continental regions, accounted for 40 % of this excess contribution. This work highlights the growing importance of addressing PMcoarse on a regional scale in future air quality research and control strategies to meet PM10 air quality targets.</p
Impact of dietary practices on DNA adduct formation by aristolochic acid I in mice: drinking alkaline water as a risk mitigation strategy
No full textBalkan endemic nephropathy (BEN) is a chronic kidney disease associated with the consumption of aristolochic acids (AAs) through contaminated food sources. AAs are known to form DNA adducts that are implicated in tumorigenesis and kidney fibrosis. Given the sensitivity of DNA adduct formation to dietary factors, this study aimed to investigate the impact of various dietary practices on AA-DNA adduct formation, thereby assessing the risk of developing BEN. We quantified AA-DNA adducts in DNA extracted from the kidneys and livers of mice subjected to high-fat, high-protein, high-sucrose, and high-salt diets, utilizing a highly sensitive liquid chromatography–tandem mass spectrometry method combined with stable isotope dilution. Our results demonstrated that unbalanced diets significantly elevated the formation of DNA adducts from AAs. Notably, mice fed high-fat diets exhibited increases in adduct levels of 71 and 114% for diets containing 17 and 25% fat, respectively. Mice on a 20% sucrose diet showed an 80% increase in adduct levels compared to those on a standard diet. Further investigations using gut sacs from the small intestines of these mice revealed that the increased level of DNA adduct formation was primarily attributed to enhanced intestinal absorption. Additionally, we observed that drinking alkaline water reduced adduct levels by 30% compared to tap water, likely by decreasing AA absorption. In contrast, commonly used dietary supplements, such as vitamin C and cysteine, significantly increased AA-DNA adduct levels by enhancing the activity of enzymes involved in the metabolic activation of AAs. These findings highlight the critical role of a balanced diet in mitigating the risk of BEN and suggest that alkaline water consumption may serve as a protective strategy for individuals living in AA-contaminated regions.<br/