Saved Queries

Background/Objectives: Studies have reported that female athletes often exhibit low levels of nutritional knowledge and inadequate dietary intake to meet their nutritional needs. The aim of this study was to evaluate the effect of a nutritional education intervention on nutrition knowledge, dietary intake, and body composition in female handball players (n = 45; age, 17.6 ± 2.1 years). Methods: A quasi-experimental intervention design was implemented, consisting of a 3-week educational program delivered through six in-person sessions led by a registered dietitian. Nutrition knowledge, dietary intake, adherence to the Mediterranean diet, and anthropometric and body composition measurements were assessed. Results: Nutrition knowledge levels were significantly higher both immediately post-intervention and three months later compared to baseline (p < 0.05, ES > 0.8). A total of 36 participants completed a 3-day dietary record at baseline and at follow-up. Initial assessments revealed insufficient energy (31 kcal/kg/day) and carbohydrate intake (3.0 g/kg/day) and a high intake of total fats (1.4 g/kg/day). During follow-up, a significant decrease in the consumption of foods rich in sugar was observed (p = 0.0272). A total of 82.2% of the players needed to improve their adherence to the Mediterranean diet. No significant changes were found in Mediterranean diet adherence or body composition following the intervention. Conclusions: The nutritional education intervention significantly improved athletes’ nutritional knowledge and significantly decreased their consumption of sugary foods; however, further studies are needed to evaluate its impact on dietary intake and body composition, considering the study’s limitations. Full article

(This article belongs to the Special Issue Food Habits, Nutritional Knowledge, and Nutrition Education)

►▼ Show Figures

Figure 1

57 pages, 647 KiB

Open AccessArticle

A Unified Perspective on Poincaré and Galilei Relativity: II. General Relativity: A. Kinematics

by Christian Y. Cardall

Symmetry 2025, 17(8), 1245; https://doi.org/10.3390/sym17081245 (registering DOI) - 5 Aug 2025

Abstract

Building on the first paper in this series (Paper I), a unified perspective on Poincaré and Galilei physics in a 5-dimensional spacetime setting is further pursued through a consideration of the kinematics of general relativity, with the gravitational dynamics to be addressed separately. The metric of the 5-dimensional affine spacetimes governed by the Bargmann groups considered in Paper I (central extensions of the Poincaré and Galilei groups) is generalized to curved spacetime by extending the usual 1 + 3 (traditionally `3 + 1’) formalism of general relativity on 4-dimensional spacetime to a 1 + 3 + 1 formalism, whose spacetime kinematics is shown to be consistent with that of the usual 1 + 3 formalism. Spacetime tensor laws governing the motion of an elementary classical material particle and the dynamics of a simple fluid are presented, along with their 1 + 3 + 1 decompositions; these reference the foliation of spacetime in a manner that partially reverts the Einstein perspective (accelerated fiducial observers, and geodesic material particles and fluid elements) to a Newton-like perspective (geodesic fiducial observers, and accelerated material particles and fluid elements subject to a gravitational force). These spacetime laws of motion for particles and fluids also suggest that a strong-field Galilei general relativity would involve a limit in which not only

c \to \infty

but also

G \to \infty

, such that

G / c^{2}

remains constant. Full article

(This article belongs to the Special Issue Recent Advance in Mathematical Physics II)

21 pages, 826 KiB

Open AccessReview

The Role of Vitamin K Deficiency in Chronic Kidney Disease—A Scoping Review

by Valdemar Tybjerg Wegge, Mette Kjær Torbensen, Allan Linneberg and Julie Aaberg Lauridsen

Nutrients 2025, 17(15), 2559; https://doi.org/10.3390/nu17152559 (registering DOI) - 5 Aug 2025

Abstract

Background/objectives: Chronic kidney disease (CKD) affects up to 15% of the global population and is driven by vascular and interstitial damage, and is most prevalent in persons with hypertension and diabetes. Vitamin K, a necessary cofactor for activation of vitamin K-dependent proteins may modulate these processes. It is well established that vitamin K deficiency is associated with CKD, but the therapeutic effects of supplementation on kidney function are still uncertain. We aimed to review the current evidence on the effect of vitamin K deficiency and supplementation on any marker of renal function and kidney disease, across general adult populations and CKD patient populations. Methods: A search was conducted in PubMed, targeting terms related to vitamin K status and CKD. Studies were included if they reported data on vitamin K status or supplementation in relation to kidney function outcomes. Results: A total of 16 studies were included. Nine interventional studies were included and confirmed that vitamin K supplementation improves biomarkers of vitamin K status but showed no consistent beneficial effects on renal function. Seven observational studies across populations found significant associations between vitamin K status and decline in kidney function; however, associations were often attenuated after adjustments. Conclusions: No clear effect of supplementation was observed on the reported kidney markers in patient populations. A clear association between low vitamin K status and impaired kidney function was confirmed. Studying heterogeneity makes the comparability and generalizability of the results difficult. Our review highlights the need for more cohort studies and clinical trials in general or patient populations. Full article

(This article belongs to the Special Issue Micronutrients and Bioactive Molecules: Their Development, Interaction, and Impact on Human Health)

22 pages, 14608 KiB

Open AccessArticle

Temporal and Spatial Evolution of Gross Primary Productivity of Vegetation and Its Driving Factors on the Qinghai-Tibet Plateau Based on Geographical Detectors

by Liang Zhang, Cunlin Xin and Meiping Sun

Atmosphere 2025, 16(8), 940; https://doi.org/10.3390/atmos16080940 (registering DOI) - 5 Aug 2025

Abstract

To investigate the spatiotemporal evolution characteristics and primary driving factors of Gross Primary Productivity (GPP) on the Qinghai-Tibet Plateau, we employed an enhanced MODIS-PSN model. Utilizing the fifth-generation global climate reanalysis dataset (ECMWF ERA5), we generated GPP remote sensing products by integrating six natural factors. Through correlation analysis and geographical detector modeling, we quantitatively analyzed the spatiotemporal dynamics and key drivers of vegetation GPP across the Qinghai-Tibet Plateau from 2001 to 2022. The results demonstrate that GPP changes across the Qinghai-Tibet Plateau display pronounced spatial heterogeneity. The humid northeastern and southeastern regions exhibit significantly positive change rates, primarily distributed across wetland and forest ecosystems, with a maximum mean annual change rate of 12.40 gC/m²/year. In contrast, the central and southern regions display a decreasing trend, with the minimum change rate reaching −1.61 gC/m²/year, predominantly concentrated in alpine grasslands and desert areas. Vegetation GPP on the Qinghai-Tibet Plateau shows significant correlations with temperature, vapor pressure deficit (VPD), evapotranspiration (ET), leaf area index (LAI), precipitation, and radiation. Among the factors analyzed, LAI demonstrates the strongest explanatory power for spatial variations in vegetation GPP across the Qinghai-Tibet Plateau. The dominant factors influencing vegetation GPP on the Qinghai-Tibet Plateau are LAI, ET, and precipitation. The pairwise interactions between these factors exhibit linear enhancement effects, demonstrating synergistic multifactor interactions. This study systematically analyzed the response mechanisms and variations of vegetation GPP to multiple driving factors across the Qinghai-Tibet Plateau from a spatial heterogeneity perspective. The findings provide both a critical theoretical framework and practical insights for better understanding ecosystem response dynamics and drought conditions on the plateau. Full article

(This article belongs to the Special Issue Climate Change Over the Tibetan Plateau and Surroundings on Decadal to Sub-Orbital Timescales and Its Driving Mechanisms)

►▼ Show Figures

Figure 1

16 pages, 532 KiB

Open AccessArticle

A Play-Responsive Approach to Teaching Mathematics in Preschool, with a Focus on Representations

by Maria Lundvin and Hanna Palmér

Educ. Sci. 2025, 15(8), 999; https://doi.org/10.3390/educsci15080999 (registering DOI) - 5 Aug 2025

Abstract

This article reports on a Swedish study investigating how children aged 2–3 years experience mathematical concepts through representations in play-responsive teaching. Drawing on the semiotic–cultural theory of learning, this study examines how representations, such as spoken language, bodily action, and artifacts, are mediated. Video-recorded teaching sessions are analyzed to identify semiotic means of objectification and semiotic nodes at which these representations converge. The analysis distinguishes between children encountering concepts expressed by others and expressing concepts themselves. The results indicate that play-responsive teaching creates varied opportunities for experiencing mathematical concepts, with distinct modes of sensuous cognition linked to whether a concept is encountered or expressed. This study underscores the role of teachers’ choices in shaping these experiences and highlights bodily action as a significant form of representation. These findings aim to inform the use of representations in teaching mathematics to the youngest children in preschool. Full article

(This article belongs to the Special Issue Early Mathematics Education with a Focus on the Teacher and the Teaching)

►▼ Show Figures

Figure 1

18 pages, 6413 KiB

Open AccessArticle

A Recognition Method for Marigold Picking Points Based on the Lightweight SCS-YOLO-Seg Model

by Baojian Ma, Zhenghao Wu, Yun Ge, Bangbang Chen, He Zhang, Hao Xia and Dongyun Wang

Sensors 2025, 25(15), 4820; https://doi.org/10.3390/s25154820 (registering DOI) - 5 Aug 2025

Abstract

Accurate identification of picking points remains a critical challenge for automated marigold harvesting, primarily due to complex backgrounds and significant pose variations of the flowers. To overcome this challenge, this study proposes SCS-YOLO-Seg, a novel method based on a lightweight segmentation model. The approach enhances the baseline YOLOv8n-seg architecture by replacing its backbone with StarNet and introducing C2f-Star, a novel lightweight feature extraction module. These modifications achieve substantial model compression, significantly reducing the model size, parameter count, and computational complexity (GFLOPs). Segmentation efficiency is further optimized through a dual-path collaborative architecture (Seg-Marigold head). Following mask extraction, picking points are determined by intersecting the optimized elliptical mask fitting results with the stem skeleton. Experimental results demonstrate that SCS-YOLO-Seg effectively balances model compression with segmentation performance. Compared to YOLOv8n-seg, it maintains high accuracy while significantly reducing resource requirements, achieving a picking point identification accuracy of 93.36% with an average inference time of 28.66 ms per image. This work provides a robust and efficient solution for vision systems in automated marigold harvesting. Full article

(This article belongs to the Section Smart Agriculture)

►▼ Show Figures

Figure 1

16 pages, 1214 KiB

Open AccessArticle

Screening of Medicinal Herbs Identifies Cimicifuga foetida and Its Bioactive Component Caffeic Acid as SARS-CoV-2 Entry Inhibitors

by Ching-Hsuan Liu, Yu-Ting Kuo, Chien-Ju Lin, Feng-Lin Yen, Shu-Jing Wu and Liang-Tzung Lin

Viruses 2025, 17(8), 1086; https://doi.org/10.3390/v17081086 (registering DOI) - 5 Aug 2025

Abstract

The emergence of SARS-CoV-2 variants highlights the urgent need for novel therapeutic strategies, particularly entry inhibitors that could efficiently prevent viral infection. Medicinal herbs and herbal combination formulas have long been recognized for their effects in treating infectious diseases and their antiviral properties, thus providing abundant resources for the discovery of antiviral candidates. While many candidates have been suggested to have antiviral activity against SARS-CoV-2 infection, few have been validated for their mechanisms, including possible effects on viral entry. This study aimed to identify SARS-CoV-2 entry inhibitors from medicinal herbs and herbal formulas that are known for heat-clearing and detoxifying properties and/or antiviral activities. A SARS-CoV-2 pseudoparticle (SARS-CoV-2pp) system was used to assess mechanism-specific entry inhibition. Our results showed that the methanol extract of Anemarrhena asphodeloides rhizome, as well as the water extracts of Cimicifuga foetida rhizome, Xiao Chai Hu Tang (XCHT), and Sheng Ma Ge Gen Tang (SMGGT), have substantial inhibitory effects on the entry of SARS-CoV-2pps into host cells. Given the observation that Cimicifuga foetida exhibited the most potent inhibition and is a constituent of SMGGT, we further investigated the major compounds of the herb and identified caffeic acid as a bioactive component for blocking SARS-CoV-2pp entry. Entry inhibition of Cimicifuga foetida and caffeic acid was validated on both wild-type and the currently dominant JN.1 strain SARS-CoV-2pp systems. Moreover, caffeic acid was able to both inactivate the pseudoparticles and prevent their entry into pretreated host cells. The results support the traditional use of these herbal medicines and underscore their potential as valuable resources for identifying active compounds and developing therapeutic entry inhibitors for the management of COVID-19. Full article

(This article belongs to the Section Coronaviruses)

20 pages, 3069 KiB

Open AccessFeature PaperArticle

Inhibitory Impact of the Amino Benzoic Derivative DAB-2-28 on the Process of Epithelial–Mesenchymal Transition in Human Breast Cancer Cells

by Laurie Fortin, Julie Girouard, Yassine Oufqir, Alexis Paquin, Francis Cloutier, Isabelle Plante, Gervais Bérubé and Carlos Reyes-Moreno

Molecules 2025, 30(15), 3284; https://doi.org/10.3390/molecules30153284 (registering DOI) - 5 Aug 2025

Abstract

Macrophage-mediated inflammation is known to be involved in the epithelial–mesenchymal transition (EMT) of various types of cancer. This makes macrophage-derived inflammatory factors prime targets for the development of new treatments. This study uncovers the therapeutic potential and action mechanism of DAB-2-28, a small-molecule derived from para-aminobenzoic acid, in the treatment of breast cancer. The luminal MCF-7 and the triple-negative MDA-MB-231 cancer cell lines used in this study represent, respectively, breast cancers in which the differentiation states are related to the epithelial phenotype of the mammary gland and breast cancers expressing a highly aggressive mesenchymal phenotype. In MCF-7 cells, soluble factors from macrophage-conditioned media (CM-MØ) induce a characteristic morphology of mesenchymal cells with an upregulated expression of Snail1, a mesenchymal marker, as opposed to a decrease in the expression of E-cadherin, an epithelial marker. DAB-2-28 does not affect the differential expression of Snail1 and E-cadherin in response to CM-MØ, but negatively impacts other hallmarks of EMT by decreasing invasion and migration capacities, in addition to MMP9 expression and gelatinase activity, in both MCF-7 and MDA-MB-231 cells. Moreover, DAB-2-28 inhibits the phosphorylation of key pro-EMT transcriptional factors, such as NFκB, STAT3, SMAD2, CREB, and/or AKT proteins, in breast cancer cells exposed to different EMT inducers. Overall, our study provides evidence suggesting that inhibition of EMT initiation or maintenance is a key mechanism by which DAB-2-28 can exert anti-tumoral effects in breast cancer cells. Full article

(This article belongs to the Special Issue Recent Advances in Development of Small Molecules to Fight Cancer—2nd Edition)

►▼ Show Figures

Figure 1

23 pages, 1650 KiB

Open AccessArticle

Generative AI-Enhanced Virtual Reality Simulation for Pre-Service Teacher Education: A Mixed-Methods Analysis of Usability and Instructional Utility for Course Integration

by Sumin Hong, Jewoong Moon, Taeyeon Eom, Idowu David Awoyemi and Juno Hwang

Educ. Sci. 2025, 15(8), 997; https://doi.org/10.3390/educsci15080997 (registering DOI) - 5 Aug 2025

Abstract

Teacher education faces persistent challenges, including limited access to authentic field experiences and a disconnect between theoretical instruction and classroom practice. While virtual reality (VR) simulations offer an alternative, most are constrained by inflexible design and lack scalability, failing to mirror the complexity of real teaching environments. This study introduces TeacherGen@i, a generative AI (GenAI)-enhanced VR simulation designed to provide pre-service teachers with immersive, adaptive teaching practice through realistic GenAI agents. Using an explanatory case study with a mixed-methods approach, the study examines the simulation’s usability, design challenges, and instructional utility within a university-based teacher preparation course. Data sources included usability surveys and reflective journals, analyzed through thematic coding and computational linguistic analysis using LIWC. Findings suggest that TeacherGen@i facilitates meaningful development of teaching competencies such as instructional decision-making, classroom communication, and student engagement, while also identifying notable design limitations related to cognitive load, user interface design, and instructional scaffolding. This exploratory research offers preliminary insights into the integration of generative AI in teacher simulations and its potential to support responsive and scalable simulation-based learning environments. Full article

(This article belongs to the Special Issue Emerging Technologies in Teaching and Learning to Solve Real-World Challenges: Perspectives, Challenges, and Future Directions)

►▼ Show Figures

Figure 1

18 pages, 13224 KiB

Open AccessArticle

The Structure and Mechanical Properties of FeAlCrNiV Eutectic Complex Concentrated Alloy

by Josef Pešička, Jozef Veselý, Robert Král, Stanislav Daniš, Peter Minárik, Eliška Jača and Jana Šmilauerová

Materials 2025, 18(15), 3675; https://doi.org/10.3390/ma18153675 (registering DOI) - 5 Aug 2025

Abstract

In this work, the microstructure and mechanical properties of the FeAlCrNiV complex concentrated alloy (CCA) were studied in the as-cast and annealed states. The material was annealed at 800 °C for 16 days to test microstructure stability and phase evolution. It was found that the microstructure does not differ in the two investigated states, and the results of differential scanning calorimetry and dilatometry showed that there is almost no difference in the thermal response between the as-cast and annealed states. Both investigated states exhibit eutectic structure with bcc solid solution and ordered phase with B2 symmetry. In a single grain, several regions with B2 laths in the bcc matrix were observed. Inside the B2 laths and in the bcc matrix, bcc spheres and B2 spheres were observed, respectively. All three features—laths, matrix and spheres—are fully crystallographically coherent. Nevertheless, in the adjacent region in the grain, the crystal structure of the matrix, laths and sphere changed to the other structure, i.e., the characteristics of the microstructure feature with B2 symmetry changed to bcc, and vice versa. Compression deformation tests were performed for various temperatures from room temperature to 800 °C. The results showed that the material exhibits exceptional yield stress values, especially at high temperatures (820 MPa/800 °C), and excellent plasticity (25%). Full article

(This article belongs to the Special Issue Mechanical Behaviour of Advanced Metal and Composite Materials)

►▼ Show Figures

Figure 1

17 pages, 5201 KiB

Open AccessArticle

Construction Scheme Effects on Deformation Controls for Open-Top UBITs Underpassing Existing Stations

by Yanming Yao, Junhong Zhou, Mansheng Tan, Mingjie Jia and Honggui Di

Buildings 2025, 15(15), 2762; https://doi.org/10.3390/buildings15152762 (registering DOI) - 5 Aug 2025

Abstract

Urban rail transit networks’ rapid expansions have led to increasing intersections between existing and new lines, particularly in dense urban areas where new stations must underpass existing infrastructure at zero distance. Deformation controls during construction are critical for maintaining the operational safety of existing stations, especially in soft soil conditions where construction-induced settlement poses significant risks to structural integrity. This study systematically investigates the influence mechanisms of different construction schemes on base plate deformation when an open-top UBIT (underground bundle composite pipe integrated by transverse pre-stressing) underpasses existing stations. Through precise numerical simulation using PLAXIS 3D, the research comparatively analyzed the effects of 12 pipe jacking sequences, 3 pre-stress levels (1116 MPa, 1395 MPa, 1674 MPa), and 3 soil chamber excavation schemes, revealing the mechanisms between the deformation evolution and soil unloading effects. The continuous jacking strategy of adjacent pipes forms an efficient support structure, limiting maximum settlement to 5.2 mm. Medium pre-stress level (1395 MPa) produces a balanced deformation pattern that optimizes structural performance, while excavating side chambers before the central chamber effectively utilizes soil unloading effects, achieving controlled settlement distribution with maximum values of −7.2 mm. The optimal construction combination demonstrates effective deformation control, ensuring the operational safety of existing station structures. These findings enable safer and more efficient urban underpassing construction. Full article

(This article belongs to the Section Building Structures)

►▼ Show Figures

Figure 1

26 pages, 769 KiB

Open AccessReview

Immunomodulatory and Regenerative Functions of MSC-Derived Exosomes in Bone Repair

by Manorathna Arun, Sheeja Rajasingh, Parani Madasamy and Johnson Rajasingh

Bioengineering 2025, 12(8), 844; https://doi.org/10.3390/bioengineering12080844 (registering DOI) - 5 Aug 2025

Abstract

Bone integrity is maintained through continuous remodeling, orchestrated by the coordinated actions of osteocytes, osteoblasts, and osteoclasts. Once considered passive bystanders, osteocytes are now recognized as central regulators of this process, mediating biochemical signaling and mechanotransduction. Malfunctioning osteocytes contribute to serious skeletal disorders such as osteoporosis. Mesenchymal stromal cells (MSCs), multipotent stem cells capable of differentiating into osteoblasts, have emerged as promising agents for bone regeneration, primarily through the paracrine effects of their secreted exosomes. MSC-derived exosomes are nanoscale vesicles enriched with proteins, lipids, and nucleic acids that promote intercellular communication, osteoblast proliferation and differentiation, and angiogenesis. Notably, they deliver osteoinductive microRNAs (miRNAs) that influence osteogenic markers and support bone tissue repair. In vivo investigations validate their capacity to enhance bone regeneration, increase bone volume, and improve biomechanical strength. Additionally, MSC-derived exosomes regulate the immune response, creating pro-osteogenic and pro-angiogenic factors, boosting their therapeutic efficacy. Due to their cell-free characteristics, MSC-derived exosomes offer benefits such as diminished immunogenicity and minimal risk of off-target effects. These properties position them as promising and innovative approaches for bone regeneration, integrating immunomodulatory effects with tissue-specific regenerative capabilities. Full article

(This article belongs to the Special Issue Recent Progress in Stem Cells and Stem Cell-Derived Biotherapeutics for Regenerative Medicine Applications)

►▼ Show Figures

Figure 1

11 pages, 1112 KiB

Open AccessArticle

Diagnostic Accuracy of Shear Wave Elastography Versus Ultrasound in Plantar Fasciitis Among Patients with and Without Ankylosing Spondylitis

by Mahyar Daskareh, Mahsa Mehdipour Dalivand, Saeid Esmaeilian, Aseme Pourrajabi, Seyed Ali Moshtaghioon, Elham Rahmanipour, Ahmadreza Jamshidi, Majid Alikhani and Mohammad Ghorbani

Diagnostics 2025, 15(15), 1967; https://doi.org/10.3390/diagnostics15151967 (registering DOI) - 5 Aug 2025

Abstract

Background: Plantar fasciitis (PF) is a common enthesopathy in patients with ankylosing spondylitis (AS). Shear wave elastography (SWE) and the Belgrade ultrasound enthesitis score (BUSES) may detect PF, but their comparative diagnostic performance is unclear. Objective: To compare SWE with the BUSES for identifying PF in individuals with and without AS. Methods: In this cross-sectional study, 96 participants were stratified into AS and non-AS populations, each further divided based on the presence or absence of clinical PF. Demographic data, the American Orthopedic Foot and Ankle Society Score (AOFAS), and the BASDAI score were recorded. All subjects underwent grayscale ultrasonography, the BUSES scoring, and SWE assessment of the plantar fascia. Logistic regression models were constructed for each population, controlling for age, body mass index (BMI), and fascia–skin distance. ROC curve analyses were performed to evaluate diagnostic accuracy. Results: In both AS and non-AS groups, SWE and the BUSES were significant predictors of PF (p < 0.05). SWE demonstrated slightly higher diagnostic accuracy, with area under the curve (AUC) values of 0.845 (AS) and 0.837 (non-AS), compared to the BUSES with AUCs of 0.785 and 0.831, respectively. SWE also showed stronger adjusted odds ratios in regression models. The interobserver agreement was good to excellent for both modalities. Conclusions: Both SWE and the BUSES are effective for PF detection, with SWE offering marginally superior diagnostic performance, particularly in AS patients. SWE may enhance the early identification of biomechanical changes in the plantar fascia. Full article

(This article belongs to the Special Issue Ultrasound Elastography in Musculoskeletal Disorders: From Bench to Bedside)

18 pages, 2879 KiB

Open AccessArticle

Smartphone-Compatible Colorimetric Detection of CA19-9 Using Melanin Nanoparticles and Deep Learning

by Turgut Karademir, Gizem Kaleli-Can and Başak Esin Köktürk-Güzel

Biosensors 2025, 15(8), 507; https://doi.org/10.3390/bios15080507 (registering DOI) - 5 Aug 2025

Abstract

Paper-based colorimetric biosensors represent a promising class of low-cost diagnostic tools that do not require external instrumentation. However, their broader applicability is limited by the environmental concerns associated with conventional metal-based nanomaterials and the subjectivity of visual interpretation. To address these challenges, this study introduces a proof-of-concept platform—using CA19-9 as a model biomarker—that integrates naturally derived melanin nanoparticles (MNPs) with machine learning-based image analysis to enable environmentally sustainable and analytically robust colorimetric quantification. Upon target binding, MNPs induce a concentration-dependent color transition from yellow to brown. This visual signal was quantified using a machine learning pipeline incorporating automated region segmentation and regression modeling. Sensor areas were segmented using three different algorithms, with the U-Net model achieving the highest accuracy (average IoU: 0.9025 ± 0.0392). Features extracted from segmented regions were used to train seven regression models, among which XGBoost performed best, yielding a Mean Absolute Percentage Error (MAPE) of 17%. Although reduced sensitivity was observed at higher analyte concentrations due to sensor saturation, the model showed strong predictive accuracy at lower concentrations, which are especially challenging for visual interpretation. This approach enables accurate, reproducible, and objective quantification of colorimetric signals, thereby offering a sustainable and scalable alternative for point-of-care diagnostic applications. Full article

(This article belongs to the Special Issue AI-Enabled Biosensor Technologies for Boosting Medical Applications)

►▼ Show Figures

Figure 1

26 pages, 10877 KiB

Open AccessArticle

Analysis of Mechanical Properties of Crumb Rubber Tires Mixed with Silty Sand of Various Sizes and Percentages

by Sindambiwe Theogene, Jianxiu Sun, Yanzi Wang, Run Xu, Jie Sun, Yuchen Tao, Changyong Zhang, Qingshuo Sun, Jiandong Wu, Hongya Yue and Hongbo Zhang

Polymers 2025, 17(15), 2144; https://doi.org/10.3390/polym17152144 (registering DOI) - 5 Aug 2025

Abstract

Every year, a billion tires are discarded worldwide, with only a small percentage being recycled. This leads to significant environmental hazards, such as fire risks and improper disposal. Silty sand also presents technical challenges due to its poor shear strength, susceptibility to erosion, and low permeability. This study explores the incorporation of crumb rubber derived from waste tires into silty sand to enhance its mechanical properties. Crumb rubber particles of varying sizes (3–6 mm, 5–10 mm, and 10–20 mm) were mixed with silty sand at 0%, 3%, 6%, and 9% percentages, respectively. Triaxial compression tests of unconsolidated and consolidated undrained tests with cell pressures of 100, 300, and 500 kPa were conducted. The deviatoric stress, shear stress, and stiffness modulus were investigated. The results revealed that the addition of crumb rubber significantly increased the deviatoric and shear stresses, especially at particle sizes of 5–10 mm, with contents of 3%, 6%, and 9%. Additionally, the stiffness modulus was notably reduced in the mixture containing 6% crumb rubber tire. These findings suggest that incorporating crumb rubber tires into silty sand not only improves silty sand performance but also offers an environmentally sustainable approach to tire waste recycling, making it a viable strategy for silty sand stabilization in construction and geotechnical engineering performance. Full article

(This article belongs to the Section Polymer Analysis and Characterization)

►▼ Show Figures

Figure 1

Show export options Show export options

Select all

Export citation of selected articles as:

Error

Oops... you haven't selected anything for export.

Displaying article 1-50 on page 1 of 2000.

Go to page 1 2 3 4 5

Search Results (899,674)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI