Search Results (17,472)

Almond gum is a resource-rich natural polysaccharide; however, its high viscosity and low solubility severely limit industrial applications in separation, purification, and functional development. This study aimed to overcome these bottlenecks by optimizing an ethylenediaminetetraacetic acid (EDTA) preparation process and evaluating its protective efficacy against colitis. Using response surface methodology, optimal conditions were identified (1% EDTA, 3 h reaction, 10 h extraction), resulting in a modified polysaccharide (EAGP) with significantly reduced viscosity (from 640.8 to 238.7 mPa·s). SEM-EDX confirmed that EDTA efficiently removed cross-linking metal ions (K, Ca, Mg), creating a porous structure that facilitates purification. The purified fraction, EAGP-W1, was characterized as an arabinogalactan primarily composed of galactose (40.51%) and arabinose (38.38%). In vivo experiments demonstrated that EAGP-W1 significantly alleviated DSS-induced colitis, reducing colonic shortening and histopathological damage (p < 0.05). Mechanistically, EAGP-W1 reshaped the gut microbiota by downregulating pro-inflammatory genera and upregulating probiotics (p < 0.05). This shift promoted the production of short-chain fatty acids (SCFAs) (p < 0.05), thereby repairing the intestinal barrier and suppressing inflammation. Overall, this study establishes an efficient EDTA-based strategy for almond gum processing and elucidates its anti-inflammatory mechanism through the “microbiota–metabolite–barrier” axis, providing a theoretical basis for its development as a high-value functional food for gut health. Full article

Ornithine decarboxylase (ODC) functions as the rate-limiting enzyme in the polyamine (PA) biosynthetic pathway. It catalyzes the decarboxylation of L-ornithine to produce putrescine, thereby initiating the biosynthesis of polyamines. Polyamines are a class of widely distributed polycationic aliphatic compounds in living organisms, including putrescine, spermidine, and spermine. They serve not only as critical regulators of cell growth, proliferation, and differentiation, but also as important signaling molecules involved in plant responses to environmental stress and key precursors in the biosynthesis of diverse secondary metabolites. Focusing on recent advances in plant ODC research, this review summarizes the characteristics and evolutionary relationships of the ODC gene family, the biochemical properties and catalytic mechanism of the enzyme, and its multiple physiological roles in growth, development, secondary metabolism, and stress adaptation. Furthermore, we discuss the complex regulatory mechanisms governing ODC activity at both transcriptional and post-translational levels, with a critical gap in understanding the post-translational regulation of ODC in plants, particularly the mechanisms governing its degradation. Unlike in animals, where antizymes mediate ODC degradation, functional analogs of antizymes have not yet been identified in plants, leaving the degradation pathway largely unexplored. Finally, we review the applications of plant genetic modification targeting ODC in enhancing the production of valuable secondary metabolites in medicinal plants and improving stress tolerance in crops, along with perspectives on future research directions. This review illustrates the diversity of ODC functions and the complexity of its regulatory mechanisms in plant growth, development, stress responses, and secondary metabolism. It also provides a theoretical foundation and insights for exploring ODC as a target for plant genetic modification, which is promising for improving the economic traits and stress resistance of horticultural plants. Full article

To address the engineering problems of high cement content, high brittleness, and weak frost resistance of cement-improved loess in the seasonal frozen soil area of Northwest China, F1 ion curing agent (F1) and cement composite improved loess (FCIL) were used in this paper. Through unconfined compressive (UC) strength tests, consolidated undrained (CU) triaxial shear tests, and microscopic pore characteristics analysis, the mechanical properties, freeze–thaw cycle deterioration law, and microscopic pore structure of FCIL were studied. The effects of cement content (C_c), F1 dosage (C_F), number of freeze–thaw cycles (N_F-T), and confining pressure (σ₃) on the strength, deformation behavior, and pore characteristics of FCIL were analyzed. The synergistic improvement mechanism of FCIL, as well as the freeze–thaw damage mechanism, was elucidated. The results show that C_c is the primary factor controlling the strength of improved loess. The incorporation of F1 can further increase UCS and markedly enhance the failure strain (ε_f), thereby achieving simultaneous improvements in strength and ductility. An appropriate mix proportion was identified as C_F = 0.2 L/m³ and C_c = 6%. After 7 d curing, FCIL exhibited a UCS of 1.35 MPa, a cohesion (c) of 205 kPa, an internal friction angle (φ) of 36.2°, and ε_f 1.8 times that of loess improved with C_c = 6% cement alone. CU triaxial shear tests indicate that, under all tested conditions, the stress–strain responses of FCIL exhibit σ3-sensitive strain-softening behavior. As C_c and σ₃ increase, triaxial peak strength (q_max) and secant modulus (E₅₀) increase significantly. Compared with natural loess (NL), FCIL shows a markedly lower porosity (n), a substantial increase in the proportion of micropores, and reductions in medium and small pores. After multiple freeze–thaw cycles, the evolution of the pore structure is effectively restrained. This indicates that the combined use of F1 and cement promotes the formation of a dense layered stacking structure, significantly improves the microscopic pore-size distribution, and enhances the mechanical performance of loess under freeze–thaw environments. Full article

Background/Objectives: Youths with cerebral palsy (CP) have reduced levels of physical activity (PA) due to motor impairments and functional difficulties. Few studies have observed its link with various factors and none in young adults with CP. This study aimed to investigate the relationships between PA and various factors in young adults with CP, such as gait function, endurance, participation, and personal/environmental influences. Methods: Participants over 15 years old with CP who underwent Clinical Gait Analysis (CGA), the 6 min walk test, and wore an actimeter (ActiGraph GT3X+) for seven days were included. PA was assessed by daily step count (NbSteps/day). Explanatory factors included the Gait Profile Score (GPS), walking speed, subjective walking perception, joint pain, fatigue, 6 min walk distance, SF-36 questionnaire scores, and lifestyle habits. Correlations, univariate, and multivariate regression models were used for the analysis. Results: Forty-seven CP patients (28 males, 19 females, mean age 23.6 years) were included, with 82% classified as GMFCS I and 18% as GMFCS II. The average NbSteps/day was 5685. Significant correlations were found between NbSteps/day and subjective perception, pain, GMFCS level, and walking speed. Multivariate regression identified walking speed and physiotherapy (PT) sessions as significant predictors of PA. Conclusions: PA in young adults with CP is linked to walking speed, GMFCS level, joint pain, fatigue, and PT. No differences have been observed between patient unilateral or bilateral CP. However, individual behaviors vary and are not fully explained by linear regression analysis. Full article

Laser surface microtexturing has emerged as an effective approach for improving the performance of adhesive joints between dissimilar materials. In this study, the influence of laser-generated micrometric surface features on the mechanical behavior of hybrid adhesive joints was investigated for two material systems: structural steel bonded to polyamide (PA66) and structural steel bonded to technical ceramic (Al₂O₃). Single-lap joints were manufactured using a two-component epoxy adhesive with two nominal bond-line thicknesses (0.1 mm and 1.0 mm). Prior to bonding, selected surfaces were modified by ultrashort-pulse laser microtexturing, producing well-defined circular features with characteristic depths on the order of tens of micrometers. The resulting microstructures were characterized using optical and scanning electron microscopy, and their geometric parameters were quantified through profilometric measurements. Mechanical performance was evaluated under shear and bending loading conditions. The results demonstrate a substantial increase in joint strength for laser-microtextured surfaces compared with non-textured references for both material combinations. The effect of surface microtexturing was more pronounced than the influence of adhesive layer thickness within the investigated range. These findings confirm that laser-induced surface microtexturing is a versatile and application-oriented surface preparation method capable of enhancing the reliability of adhesive bonding in hybrid metal–polymer and metal–ceramic assemblies. Full article

Carbon dioxide emissions from fossil fuel burning remains a severe environmental challenge that needs to be addressed. Deep eutectic solvents (DESs) have emerged as promising alternatives to conventional alkanolamines for CO₂ capture applications due to their lower volatility and reduced corrosion potential. In this work, two tetrabutylammonium bromide (TBAB)-based systems were synthesized using different hydrogen bond donors: 2-amino-2-methyl-1-propanol (AMP) at a 1:1 molar ratio and p-toluenesulfonic acid (PTSA) at a 1:2 molar ratio. FTIR spectroscopic analysis confirmed that TBAB-AMP (1:1) forms a true DES through hydrogen bonding interactions, whereas TBAB-PTSA (1:2) undergoes proton transfer to form an ionic salt. CO₂ solubility measurements were conducted using the pressure drop method up to 15 bar at 30 °C. The TBAB-AMP system exhibited a CO₂ uptake of 0.194 mol CO₂/mol DES at 14.7 bar, approximately 2.5-fold higher than the TBAB-PTSA system, which achieved 0.079 mol/mol at 14.5 bar. Critical and thermophysical properties were estimated using the modified Lydersen–Joback–Reid, Lee–Kesler, and Haghbakhsh group-contribution methods. Viscosity measurements conducted from 30 to 50 °C revealed that TBAB-AMP exhibited significantly lower viscosity, ranging from 163 to 46 mPa·s, compared to TBAB-PTSA, which showed viscosity values between 536 and 155 mPa·s. The superior CO₂ capture performance of the amine-functionalized DES was attributed to favorable hydrogen-bonding interactions, lower viscosity, which enabled better mass transfer, and enhanced chemical affinity toward CO₂ through carbamate formation. Full article

Carbon nanotube yarns (CNTYs) have received more consideration recently due to their excellent specific mechanical, electrical and thermal properties, making them promising materials for different applications. Until now, the axial properties of the yarn have been thoroughly investigated; however, the transverse or radial properties, orthogonal to the fiber axis, remain relatively unknown due to the challenges associated with their measurement. In this study, the transverse or radial response of the CNTY including its elastic modulus was determined using Atomic Force Microscopy (AFM) and Raman Spectroscopy. Determining transverse properties in fibrous materials presents challenges owing to their geometry, inherent anisotropy, whereby mechanical characteristics exhibit directional disparities; i.e., the properties in the transverse direction may be several orders of magnitude smaller than those in the axial direction. To overcome these difficulties, AFM was utilized to perform nanoindentation experiments, where a tipless flexible cantilever probe was used to apply a controlled force to the CNTY surface. The resulting indentation depth was then analyzed to determine the transversal elastic modulus. Preliminary findings indicate that the transverse elastic modulus of the CNTYs ranges from 10–54 kPa for strain levels below 3%. Complementary Raman spectroscopy provided insight into the bulk-scale mechanical behavior of CNTYs. Incremental compressive loading between microscope slides induced nonlinear upshifts in the 2D Raman band (from ~2686.6 to 2691.4 cm⁻¹), indicating nanoscale tube realignment, inter-tube densification, and compaction. From lateral diameter measurements under load, a stress–strain curve was constructed, revealing three distinct regimes: one with an initial elastic modulus of 3.12 MPa (0.3–11.2% strain), another one with an elastic modulus increasing to 8.46 MPa (11.2–14.4%), and finally one with an elastic modulus peaking at 16.86 MPa beyond 14.4% strain. Together, these methods delineate the hierarchical and anisotropic nature of CNTYs, validating the importance of multiscale mechanical characterization for their deployment in piezoresistive sensors and multifunctional composites. This study establishes a robust framework for quantifying the transverse mechanical response of CNTYs. Full article

In this study, rice-husk fiber (RHF) extracted via alkali hydrolysis was used as a reinforcing material (0–10 wt%) in a pectin-sodium alginate (PE/SA) matrix to develop biofilms by the casting method. These biofilms were characterized by using FTIR, XRD, TGA, and DSC. The thickness, moisture content, water solubility, swelling behavior, water-contact angle, water-vapor permeability, optical transparency, and mechanical properties of biofilms were investigated. It was observed that the PE/SA/RHF film loaded with 5% RHF had better visual attributes, and a further increase in reinforcement was not found to be as favorable. The addition of 10 wt% RHF significantly enhanced the thickness from 0.094 to 0.127 mm, water solubility from 49.25 to 56.13%, water-contact angle from 48.4 to 62.6°, and tensile strength from 4.17 to 10.23 MPa. However, decreases in water-vapor permeability from 1.94 × 10⁻⁹ to 1.32 × 10⁻⁹ g·m⁻¹·Pa⁻¹·s⁻¹ and in elongation at break from 19.24 to 2.87% were observed in the biofilms. Structurally, FTIR confirmed intermolecular hydrogen bonding between components. XRD revealed that the films remained predominantly amorphous, without significant crystalline alterations. Furthermore, thermal stability improved with the addition of RHF. Finally, these PE/SA/RHF composite films may be potential eco-friendly biodegradable packaging candidates for food industry applications. Full article

Composite solid propellant mixers face severe post-mixing cleaning challenges, especially for high-burn-rate propellants. Manual cleaning remains necessary due to the high viscosity and friction sensitivity of energetic ballistic modifiers (EBMs), which hinders automation and poses safety risks. This study explores the wall slip behavior of high-burn-rate propellants (non-Newtonian fluids)—a phenomenon that departs from the no-slip boundary condition in fluid mechanics (where fluid velocity at the solid surface is assumed to be zero) and occurs when the applied shear stress exceeds a critical value—and its application in mixer cleaning. We performed rheological tests using HAAKE Viscotester IQ (Couette system) (Thermo Fisher Scientific, located in Karlsruhe, Germany) and TA/ARES-G2 rheometer (parallel plate system) (TA Instruments, located in New Castle, DE, USA) to analyze the shear stress, viscosity, and wall slip characteristics of the propellants and inert materials. Tests on three inert materials (A, B, C) showed that A and B exhibit wall slip with shear stress exceeding 2313.6 Pa, achieving complete or near-complete residue removal. In contrast, C does not exhibit wall slip and has insufficient stress, resulting in poor cleaning performance. This work verifies that leveraging the wall slip behavior of high-burn-rate propellants with inert materials can achieve manual-free mixer cleaning, laying a foundation for future unmanned, automated cleaning of high-burn-rate propellant mixers. Full article

Climate change (CC) is widely recognized as a major human concern, affecting society across all aspects and activities. Among various economic sectors, aviation is one of the most affected due to its exposure to adverse weather events. Consequently, adaptation and mitigation actions are becoming increasingly important to reduce the negative effects of CC-driven extreme weather events on aviation operations. In this study, we analyzed 30 years of historical aerodrome meteorological routine reports (METARs) from several major Italian airports to assess multi-decadal changes in aviation weather-related hazards, based on observational evidence such as convection, visibility, and snow and freezing precipitation. Furthermore, we examined the ERA5 reanalysis dataset to assess potential anomalies in the synoptic circulation over the Euro-Mediterranean region that may drive fluctuations in local airport climatology. Our results reveal relevant trends for the considered aviation-related weather hazards, while also indicating meaningful links to variations in local and synoptic patterns. The observed increases in 500 hPa geopotential height, 850 hPa temperature, and convective available potential energy (CAPE) lead to changes in the climatology of the airports considered, including a general enhancement of thermoconvective phenomena, a reduction in events associated with synoptic-scale disturbances, an overall decrease in snowfall, and contrasting trends in fog occurrence depending on local factors. Full article

In Hungary, a fast-growing Empress tree hybrid (×Paulownia Clone in vitro 112) also known as Smaragdfa^® has been developed as a low-density plantation species seeking industrial utilization. Many potential industrial applications presuppose its bonding. The presence of adhesives in bonded layered assemblies, with differing climatic conditions on the internal and outer side, may induce undesired internal strains due to restricted water vapor diffusion, especially in the case of Smaragdfa as a low-density wood species. For decades, lasures have been specifically formulated with a molecular structure that allows partial vapor transmission while hindering water diffusion. Lasure-coated samples were used as control samples to identify, among the different custom-made MW adhesives, the one with diffusion properties closest to those of the lasure. Uncoated Smaragdfa wood samples were used as the baseline reference to evaluate the effect of different adhesive and coating systems on water vapor diffusion. Smaragdfa samples were prepared both uncoated and coated with different adhesive and lasure layers. Experiments were conducted following ISO 12572 and ASTM E96 standards using the cup method, with all specimens pre-conditioned to 12% moisture content. Results showed that the uncoated Smaragdfa exhibited the highest diffusion coefficient (δ = 7.02 × 10⁻¹³ kg/(m·s·Pa)) and flow rate (G = 0.055763 g/h), while the commercial adhesive-coated sample displayed an 84% reduction in diffusion capacity (δ = 1.15 × 10⁻¹³ kg/(m·s·Pa)), indicating a strong vapor-blocking effect. The lasure coating allowed partial vapor transmission, confirming its semi-permeable nature. Adhesives formulated with varying polyol molecular weights (Series 1–5) revealed a clear molecular-weight-dependent diffusion behavior: low-MW systems (S1) acted as strong diffusion barriers comparable to lasure-coated samples (SMW_L), in the same time high-MW systems (S4, S5) permitted excessive diffusion but induced microcracking, while intermediate formulations (S2, S3) achieved the most balanced performance, combining moderate diffusion with structural stability. Overall, the findings confirm that adhesive layers significantly influence water vapor transmission through Smaragdfa wood, with the degree of hindrance closely related to the molecular weight of the polyol matrix. The optimized formulations (S2, S3) demonstrate promising potential for use in bonded assemblies and engineered wood products where controlled vapor diffusion and mechanical reliability are critical in order to support reduced strains caused by water vapor. Full article

Coffee, as a perennial commodity crop, plays a crucial role in global agricultural markets, regional livelihoods, and poverty alleviation. Yunnan Province of China (21°8′–29°15′N) represents the northernmost coffee-growing region worldwide, and its production has gained increasing attention in international markets. However, the absence of a spatially explicit and high-resolution coffee distribution dataset has constrained environmental assessment, land-use analysis, and policy-making in this subtropical and marginal growing region. In this study, we developed the first 10 m resolution Arabica coffee distribution dataset for Yunnan Province for the year 2023 using Sentinel-2 optical imagery and Shuttle Radar Topographic Mission (SRTM) terrain data within the Google Earth Engine (GEE) platform. An object-based workflow was implemented to generate spatially coherent mapping units, followed by supervised classification to identify coffee plantations. The resulting map achieved an overall accuracy (OA) of 0.87, with user accuracy (UA), producer accuracy (PA), and F1 score of 0.90, 0.96, and 0.93 for the coffee class, demonstrating its reliability for regional-scale applications. Feature contribution analysis indicates that shortwave infrared (SWIR) and red-edge information, particularly during the dry season, plays an important role in coffee discrimination. These results enhance confidence in the ecological relevance and stability of the mapping framework. The proposed workflow provides a practical and transferable approach for perennial crop mapping in complex mountainous environments. More importantly, the generated high-resolution coffee distribution dataset establishes a spatial baseline for monitoring land-use dynamics, assessing ecological impacts, and supporting sustainable coffee development in southwestern China. Full article

Addressing the thermal management challenges of prismatic aluminum shell lithium battery modules in electric vehicles under high-rate charge–discharge conditions, this study proposes a multi-objective optimization design method for integrated biomimetic liquid cooling plates. By integrating various highly efficient heat transfer structures from nature, including fractal-tree-like networks, leaf vein branching systems, and spider web radial distribution, a novel biomimetic liquid cooling plate topology was constructed. A multi-physics coupled numerical model considering electrochemical heat generation, thermal conduction, convective heat transfer, and thermal stress deformation was established. The NSGA-II algorithm was employed to globally optimize 12 design variables including channel geometric parameters, operating conditions, and structural dimensions, achieving collaborative optimization objectives of maximum temperature minimization, temperature uniformity maximization, pressure drop minimization, and structural lightweighting. The weight coefficients for the four optimization objectives were determined through the Analytic Hierarchy Process (AHP) with verified consistency (CR = 0.02 < 0.10), ensuring rational priority allocation aligned with automotive safety standards. The optimization results demonstrated that compared to the initial design, the optimal solution reduced the maximum temperature under 3C discharge conditions by 9.9% to 34.7 °C, decreased the temperature difference by 31.3% to 3.3 °C, lowered the pressure drop by 24.6% to 2150 Pa, reduced structural mass by 4.0%, and decreased maximum stress by 16.7%. Quantitative comparison with single biomimetic structures under identical boundary conditions showed that the integrated design achieved a 3.3% lower maximum temperature and 25.7% better flow uniformity than the best-performing single structure, demonstrating the synergistic advantages of multi-biomimetic integration. These synergistic performance improvements can be attributed to the hierarchical multi-scale architecture where fractal networks provide macro-scale flow distribution, leaf vein branches ensure meso-scale coverage, and spider web radials achieve micro-scale thermal matching. Long-term cycling tests conducted at 1C/1C rate with 25 ± 1 °C ambient temperature showed that the optimized design maintained a capacity retention rate of 92.3% after 1000 charge–discharge cycles, demonstrating excellent durability. The complex biomimetic channel structure can be fabricated using selective laser melting technology with minimum feature sizes below 0.3 mm, indicating promising manufacturing feasibility. The research findings provide theoretical guidance and technical support for the engineering design of high-performance battery thermal management systems. Full article

Introduction: Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by an impaired ventilatory response to hypercapnia and hypoxia, particularly during sleep, and frequently associated with autonomic dysfunction. It is caused by pathogenic variants in the PHOX2B gene. Although CCHS is typically diagnosed in the neonatal period, milder forms may present later in infancy or childhood, often triggered by respiratory infections. Case presentation: We report the case of 16-month-old male diagnosed with CCHS following an episode of hypoxemic–hypercapnic respiratory failure during respiratory syncytial virus (RSV) infection. His medical history included neonatal respiratory distress requiring oxygen therapy and recurrent wheezing. At 15 months, he developed acute respiratory distress with severe hypercapnia (PaCO₂ 70 mmHg), requiring admission to the Pediatric Intensive Care Unit and invasive mechanical ventilation. Persistent sleep-related hypercapnia and hypoxemia prompted evaluation for central hypoventilation, confirmed by means of transcutaneous capnography and nocturnal pulse oximetry. Genetic testing revealed a de novo nonsense mutation in exon 1 of PHOX2B (p.Tyr14Ter). Brain magnetic resonance imaging showed diffuse white matter changes suggestive of gliosis. Further investigations identified early-onset systemic hypertension, requiring antihypertensive therapy. The patient was discharged on nocturnal non-invasive ventilation and enrolled in a neurodevelopmental rehabilitation program. Conclusions: This case highlights the phenotypic variability of CCHS and the importance of considering this diagnosis in children presenting with unexplained hypercapnia and sleep-related hypoxemia. It underscores the need for comprehensive autonomic evaluation, including blood pressure monitoring. The p.Tyr14Ter variant may allow partial protein function, potentially accounting for the relatively mild phenotype. Full article

In the face of the dual challenges of global climate change and rapid urbanization, optimizing the ecosystem services of urban green spaces has become a key strategy for building resilient and sustainable cities. This is particularly crucial in ecologically fragile arid and semi-arid regions. To accurately assess the thermal regulation function of urban green spaces, this study selected 20 parks in Xi’an, China. Combining remote sensing and Geographic Information System (GIS) technology, we adopted four established cooling indicators—Park Cooling Area (PCA), Park Cooling Efficiency (PCE), Park Cooling Intensity (PCI), and Park Cooling Gradient (PCG)—to systematically evaluate the thermal regulation functions of urban parks and their landscape-driving mechanisms. The results indicated that the average cooling amplitude of the parks was 2.53 °C, with an effective influence distance reaching 323.9 m, exhibiting a significant spatial gradient decay. We found a non-linear trade-off between green space scale and efficiency: while large parks provided a wider absolute cooling range, small and medium-sized parks demonstrated higher efficiency per unit area. Furthermore, a blue-green synergistic configuration significantly enhanced the mitigation of the urban heat island effect. The study confirmed that Park Area (PA), Park Perimeter (PP), and the Normalized Difference Vegetation Index (NDVI) significantly promoted cooling effects, whereas landscape fragmentation inhibited ecological benefits. This study elucidates the comprehensive regulation mechanism of urban parks on the urban microclimate, providing planning guidance for implementing Nature-based Solutions (NbS) and achieving climate-adaptive development in arid and semi-arid cities within the context of urban renewal. Full article