Search Results (5,909)

Background: Loss of epithelial integrity leaves the wound bed open to opportunistic bacterial colonization, and the risk of secondary infection persists for as long as the defect remains unclosed. Wound dressings must therefore provide an immediate external barrier while accelerating restoration of the skin’s own barrier. This study aims to develop and evaluate a bioactive nanotechnological platform comprising dexpanthenol (Dxp)-engineered extracellular vesicles (EVs) embedded within cross-linked hyaluronic acid hydrogels (HA@Dxp-engineered EVs) for targeted wound treatment and protection against external contaminants. Methods: EVs were engineered via exogenous (extrusion; Exo EV) and endogenous (co-incubation; Endo EV) strategies to encapsulate Dxp. The physicochemical properties of the HA@Dxp-engineered EV systems were characterized, and their therapeutic efficacy was validated through in vitro assays, including fibroblast migration and endothelial tube formation, and in vivo using a full-thickness excisional wound model in mice. Results: Both engineering strategies successfully encapsulated Dxp while preserving the structural integrity of the EVs. The HA hydrogel enabled sustained EV release and provided a physical barrier. In vitro, HA@Endo EVs significantly promoted fibroblast proliferation, migration, and the formation of mature capillary-like networks in HUVECs compared to controls. In vivo, the HA@Endo EV group demonstrated accelerated wound closure, achieving 99.88% healing by day 10, and promoted tissue remodeling with upregulated expression of COL1A1, VEGF, and HIF-1α. Conclusions: The HA@Endo EV system provides a dual-action strategy against secondary infection risk. It supplies an immediate physical barrier over the wound bed and simultaneously accelerates re-epithelialization, thereby shortening the interval during which the tissue remains exposed. Full article

This article is a continuation of research conducted by the authors on the effects of fire on cementitious composites and presents findings of an investigation into cement mortars that incorporate monofilament (I) and multifilament (F) polypropylene fibres following exposure to temperatures between 100 and 600 °C. Research was undertaken to examine the effect of adding fibre on the mechanical performance, microstructural characteristics, and thermochemical degradation behaviour of the mortars under conditions representative of high-temperature exposure during fires in energy infrastructure facilities. The scope of the research comprises establishing the modulus of elasticity using dog-bone-shaped specimens, as well as flexural and compressive strength tests performed on prisms measuring 4 × 4 × 16 cm and on 10 × 10 × 10 cm cubes to determine the strength class of the mortars. Microstructural analyses complemented the mechanical testing, performed with the use of scanning electron microscopy (SEM); this made it possible to assess temperature-induced changes in the cement matrix. The results have demonstrated that polypropylene fibres had a significant influence on the degradation behaviour of mortars subjected to elevated temperatures, particularly those between 200 and 400 °C, where fibre melting promoted the formation of additional pore channels. This phenomenon promotes the dissipation of internal energy associated with boiling water vapour contained in the capillary pores, as well as water released during the dehydration of cement hydration products, thereby limiting rapid pressure build-up and reducing the risk of explosive spalling. Moreover, the observed microstructural changes were associated with progressive decomposition of C–S–H gels and other thermo-chemical processes occurring within the cement matrix. The results confirm that polypropylene fibres act as a passive mechanism for the dissipation of thermal and mechanical energy in cement mortars, which has a positive effect on their performance under high-temperature conditions. The study provides new experimental data of significance for the design of cement-based materials with enhanced resistance to thermal exposure in energy-sector facilities. Full article

Understanding chloride transport in fly ash cement pastes is essential for improving durability, yet the relationships between pore structure parameters and the apparent chloride diffusion coefficient remain insufficiently understood. This study investigates these relationships and assesses the relative associations of selected pore structure parameters with the apparent chloride diffusion coefficient within the present experimental dataset. Cement pastes with 0–70% fly ash were prepared at a water-to-binder ratio of 0.53 and cured for 90 days. The hydration phase assemblage was assessed by X-ray diffraction and thermogravimetric analysis, with particular attention to portlandite (CH), ettringite (AFt), and layered calcium aluminate hydrate (AFm) phases. Pore structure was characterized by nitrogen adsorption and mercury intrusion porosimetry. The apparent chloride diffusion coefficient was evaluated by fitting water-soluble chloride profiles obtained from bulk diffusion tests conducted for 30, 60, and 90 days. Fly ash significantly altered the CH content, AFm phase assemblage and pore structure. At fly ash replacement levels of 50–70%, capillary porosity increased from 20.77% at 50% fly ash to 30.31% at 70% fly ash, while the critical pore diameter increased from 47 nm to 75 nm, indicating substantial pore coarsening. At 90 days, the apparent chloride diffusion coefficient initially decreased from 6.3 × 10⁻¹² m²/s for pure cement to 5.7 × 10⁻¹² m²/s at 30% fly ash replacement and then increased to 10.1 × 10⁻¹² m²/s at 70% fly ash replacement. Among the investigated pore structure parameters, critical pore diameter showed the strongest association with the apparent chloride diffusion coefficient after 90 days of immersion (R² = 0.791). Full article

Disruptions in folate (vitamin B9) and vitamin B12 metabolism, including nutritional deficiency, folate receptor alpha (FRα) autoantibodies, and MTHFR/DHFR polymorphisms, impair one-carbon metabolism and produce measurable retinal structural, microvascular, and functional changes, offering a non-invasive window into systemic and cerebral metabolic dysfunction, particularly cerebral folate deficiency (CFD). This review synthesizes peer-reviewed evidence on retinal alterations linked to folate/B12 deficiency, hyperhomocysteinemia, FRα autoantibody syndromes, and MTHFR/DHFR variants, alongside artificial intelligence (AI) and machine learning (ML) approaches applied to retinal imaging for metabolic, anemic, and nutritional optic neuropathy detection. Three convergent phenotypes emerge: structural changes (retinal nerve fiber layer and ganglion cell complex thinning, optic disc pallor, chorioretinal atrophy), microvascular abnormalities (reduced vessel density, foveal avascular zone enlargement, capillary dropout), and functional deficits (centrocecal scotoma, dyschromatopsia, reduced contrast sensitivity); they arise from homocysteine-mediated endothelial toxicity, mitochondrial impairment, and eNOS uncoupling. Existing AI/ML models for anemia and optic neuropathy establish technical feasibility but do not target folate-specific phenotypes. We propose a dedicated multimodal ML framework integrating structural, perfusion, functional, and biochemical/genetic data as a research agenda for automated, non-invasive CFD detection. Given the established folate–autism spectrum disorder (ASD) risk association reported in FRAA-positive cohorts, such a framework, once validated, could support prenatal and neonatal screening in FRAA-positive or genetically high-risk pregnancies, enabling earlier leucovorin treatment and reducing neurodevelopmental risk. Full article

Peripheral blood mononuclear cell (PBMC) bioenergetic profiling has emerged as a promising minimally invasive tool for assessing immunometabolic health, yet traditional venepuncture presents practical barriers for certain populations and longitudinal studies. This study examined PBMC bioenergetic profiles from upper-arm capillary blood using the Tasso+ device and compared these to traditional venepuncture. Healthy adults provided paired capillary and venous blood samples at rest and following maximal exercise. PBMCs were isolated and assessed using Seahorse XF technology for mitochondrial respiration and glycolytic function, alongside haematological and T-cell immunophenotyping via flow cytometry. Bland–Altman analysis demonstrated narrow limits of agreement and small mean bias between sampling methods for T-cell subsets and normalised bioenergetic parameters, whereas absolute bioenergetic rates showed wider limits of agreement with a consistently greater negative bias, indicating systematically lower values in capillary compared with venous samples. Formal equivalence testing confirmed method equivalence for only total CD4⁺ T cells and CD4⁺ naïve T cells at rest. For bioenergetic parameters, equivalence was demonstrated for proton leak respiration, mitochondrial health index, ATP supply rate, and glycolytic metrics. Absolute mitochondrial and glycolytic rates were not equivalent between methods. Both sampling methods preserved PBMC activation capacity following PMA/ionomycin stimulation. Our findings support capillary blood sampling using the Tasso+ device as a minimally invasive alternative to venepuncture for PBMC metabolic phenotyping and immunological assessments. However, caution should be exercised if using the methods interchangeably, given that only selected bioenergetic parameters and T-cell subsets demonstrate acceptable equivalence. Full article

Wicking geotextiles are specialized geosynthetics designed to regulate soil moisture through a combination of capillary-barrier and lateral-drainage mechanisms. Laboratory and field studies demonstrate their effectiveness in reducing volumetric water content, restricting capillary rise, and maintaining subgrade and base stability under rainfall, dry–wet cycles, freeze–thaw cycles, and traffic loading. Performance is influenced by soil type, fines content, installation depth, edge exposure, and environmental conditions. Field applications show benefits in pavements, expansive soils, pumping-prone sections, cold-region roadbeds, and permeable urban infrastructure. Multi-layer and composite geotextiles further enhance hydraulic and mechanical performance. Despite these advantages, gaps remain in standardized testing, long-term monitoring, design methods, and durability assessments under aggressive conditions. This review synthesizes recent experimental and field evidence, highlighting mechanisms, performance factors, and research needs to guide the optimal design and application of wicking geotextiles in geotechnical engineering. Full article

The article presents the results of systematic numerical studies on the efficacy of low-concentration nanoemulsions for enhanced oil recovery. A series of computational investigations was conducted to examine the displacement regimes of oil from digital core models with varying permeability using the developed low-concentration diesel fuel-based nanoemulsions. The volume fraction of diesel fuel in the emulsions was 1 vol.%. The volume fraction of the emulsifier ranged from 0.05% to 0.4%. The nanoemulsions demonstrated high efficiency across the entire range of permeabilities considered. It was shown that the behavior of the displacement front for water and for emulsions differs fundamentally. The waterflood front for emulsions is significantly more uniform and exhibits more complete cross-sectional saturation of pore channels compared to water flooding. With an increase in the capillary number, the oil displacement coefficient achieved by nanoemulsions increases. However, the maximum incremental effect from the use of nanoemulsions is observed at the minimum values of the capillary number. This finding indicates that the primary mechanisms underlying the positive impact of emulsions on oil displacement are the reduction in interfacial tension and the improvement of wettability. Full article

Mucosal microbiota contribute broadly to host defense and immune homeostasis, while the lung and gut microbiota form a particularly important bidirectional ecological and immunological network that shapes pulmonary host defense, inflammatory injury, and tissue repair. In pneumonia, loss of colonization resistance and altered microbial metabolite production may weaken innate and adaptive immunity; respiratory infection, antibiotics, and critical-care exposures can, in turn, remodel both microbial communities. In acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), intestinal barrier failure, circulating microbial products, immune cell trafficking and, in selected settings, lymphatic or hematogenous dissemination of gut-derived organisms may aggravate alveolar–capillary injury. Alveolar macrophages integrate these signals through pattern-recognition, metabolic, and epigenetic pathways, linking microbial ecology to pathogen clearance and inflammatory resolution. The evidence, however, remains uneven. Mechanistic causality rests largely on animal studies, most human data are associative, and trials of microbiota-directed interventions are heterogeneous and strain-specific. This Review examines bacterial and viral pneumonia, sepsis-associated ALI and ventilator-associated injury; separates mechanistic, observational, and interventional evidence; and evaluates probiotics, live biotherapeutic products, microbial metabolites, and dietary approaches. Translation will depend on longitudinal sampling, source-resolved microbial tracking, metabolite-informed patient stratification, and adequately powered trials with clinically relevant endpoints. Full article

The shaft resistance of cast-in-place piles in permafrost regions is commonly estimated using the initial moisture content and frozen-soil strength parameters obtained during site investigation. However, concrete hydration heat disturbs the temperature field of the surrounding frozen soil. During thawing and subsequent refreezing, this disturbance induces unfrozen-water migration and moisture redistribution. The resulting changes in the frozen pile–soil interface may cause the measured shaft resistance to deviate from the initial design estimate. In this study, laboratory direct shear tests and engineering-oriented reduced-scale pile–soil segment tests were conducted. The effects of initial moisture content and soil stratification on interface shear strength, the surrounding temperature field, and the post-test moisture distribution were investigated. Vertical pile compression tests were also performed to evaluate changes in pile shaft resistance. The main results are as follows. (1) The shear strength of the concrete–frozen-soil interface varied nonlinearly with moisture content. It increased initially and then decreased, reaching its maximum at a moisture content of 30%. (2) The temperature rise in the surrounding frozen soil was jointly controlled by soil stratification and initial moisture content. Higher moisture contents produced smaller peak temperature rises. In the near-pile region, the maximum difference in peak temperature among soil layers with different moisture contents was approximately 10.8%. (3) During thawing and refreezing, moisture migration was jointly affected by the temperature gradient and the moisture conditions of different soil layers. Unfrozen water migrated toward colder regions or lower-moisture soil layers under temperature gradients, capillary effects, and freezing suction, resulting in near-pile moisture depletion and localized moisture enrichment. For the Group A model, the initial-state estimate underestimated the measured peak shaft resistance by 12.45%. In contrast, for the layered B1 model, the initial-state estimate overestimated the measured peak shaft resistance by 20.58%. (4) A preliminary lumped equivalent coefficient, k_eq, was introduced to establish a relationship between moisture content and local equivalent interface resistance. After the measured post-test near-pile moisture distributions were incorporated into the calculation, the relative deviation decreased from 12.45% to 7.36% for Group A and from 20.58% to 9.66% for B1. Full article

Since the thrust of a single-emitter Field Emission Electric Propulsion (FEEP) thruster is limited to 1–20 µN, a multi-emitter configuration is necessary to increase the thrust capacity. This study proposes a hybrid multi-emitter configuration designed to achieve uniform current distribution, enhanced thrust, and high efficiency. The design consists of linearly arrayed hybrid emitters, dummy emitters, and a slit extractor. Preliminary experiments investigated Taylor cone formation and ion emission characteristics. Capillary emitters exhibited pulse, oscillating, and continuous emission modes depending on the power supply method, whereas hybrid emitters exhibited only continuous emission with well-confined Taylor cone formation and consistent current–voltage characteristics. Key design requirements for the hybrid multi-emitter configuration include axially aligned electric field distribution and a large extractor hole diameter. The proposed configuration generates the required electric field distribution with the aid of dummy emitters, achieving uniform current emission across the emitter array. The calculated maximum thrust and emitter power-to-thrust ratio were 279.0 µN and 160.4 mW/µN, respectively, at an emitter current of 2.86 mA. These results demonstrate the potential of the proposed hybrid multi-emitter configuration as a scalable emitter architecture for FEEP thruster applications requiring uniform ion emission and increased thrust capacity. Full article

Healthcare-associated infections remain a major public health challenge, and primary health care (PHC) plays a critical role in preventing and interrupting transmission within communities. This study assessed knowledge and self-reported adherence to Standard Precautions and Transmission-Based Precautions among nursing professionals working in PHC. The findings were subsequently interpreted through the conceptual perspective of Infection Containment Readiness (ICR). A cross-sectional census study was conducted in 16 PHC units in Mato Grosso do Sul, Brazil, including 75 eligible nursing professionals. Knowledge was assessed using a validated instrument comprising 47 items distributed across five domains, while adherence was evaluated through 12 self-reported practice indicators. Overall knowledge was satisfactory, with a mean accuracy rate of 78.9%. Higher performance was observed in medication safety and sharps disposal (92.0%), glove use (81.8%), and hand hygiene (77.0%), whereas lower scores were identified in risk recognition (75.6%) and respiratory precautions and cough etiquette (68.2%). Important misconceptions were identified regarding tuberculosis transmission and respiratory infection control. Self-reported adherence was heterogeneous, particularly for respiratory protection measures, tuberculosis-related practices, glove use during capillary blood glucose testing, and participation in continuing education activities. Based on the observed findings and current infection prevention literature, we propose a hypothesis-generating conceptual framework for interpreting ICR in PHC. These findings suggest that strengthening infection prevention in PHC requires strategies that address not only knowledge acquisition but also risk recognition, contextual decision-making, and organizational support for preventive practices. Full article

The severe early-age shrinkage of alkali-activated slag is a primary bottleneck restricting its engineering application. In this work, a novel shrinkage control strategy is proposed, dominated by the physical control of vacuum dehydration and assisted by the chemical compensation of MgO. The synergistic mechanism of this strategy in the AAS system was revealed by multi-scale characterization methods (XRD, FTIR, TG, NMR, BSE, and pore solution analysis). Firstly, vacuum dehydration greatly advances the development window of capillary pressure to the early stage (<6 h) of the material in the significant viscoelastic stage by forcibly removing free water between the interlayer and capillary pores. Most of the shrinkage strain energy can be dissipated through the early creep behavior of the slurry, and the strong negative pressure induces the conversion of mesopores to macropores, thereby effectively reducing the equilibrium capillary cracking driving force. Secondly, the late hydration of an appropriate amount of MgO generates magnesium silicate and hydrotalcite phases, which provide a continuous chemical micro-expansion for the matrix to compensate for residual shrinkage and moderately optimize the local pore defects induced by dehydration. The results show that in the sodium silicate solution and sodium hydroxide activating system, the synergistic effect reduces the total shrinkage rate of 28 days by 37.86% and 29.26%, respectively. Additionally, the compressive strength of hardened samples increases by about 20%. This study provides a new theoretical basis for the design of low-shrinkage and high-performance alkali-activated materials based on the physical–chemical coupling mechanism. Full article

Azelaic acid (AZA) and salicylic acid (SA) are widely used active ingredients in pharmaceutical and cosmetic formulations for the treatment of acne, rosacea, hyperpigmentation, and other dermatological conditions. Despite their frequent co-administration, analytical methods for their simultaneous determination remain limited. In the present study, a capillary electrophoresis (CE) method with indirect UV detection was developed and validated for the simultaneous determination of AZA and SA in pharmaceutical and cosmetic preparations. Preliminary experiments demonstrated that direct UV detection was unsuitable because of the weak UV absorbance of AZA; therefore, indirect UV detection based on a sodium benzoate background electrolyte (BGE) was used. Following an initial one-factor-at-a-time (OFAT) screening, method optimization was performed using a face-centered central composite design (CCD) to evaluate the effects of BGE concentration, BGE pH, and separation voltage on the separation. The optimum separation was achieved using a 30 mM sodium benzoate BGE at pH 6.5 containing 5% (v/v) methanol, a separation voltage of +18 kV, a capillary temperature of 20 °C, and indirect UV detection at 230 nm. Baseline separation of both analytes was achieved within 5 min. The method was validated according to the ICH Q2(R2) guideline and demonstrated satisfactory accuracy, linearity, precision, selectivity, sensitivity, and robustness. The developed procedure was successfully applied to the analysis of commercial cosmetic formulations containing AZA, SA, or both active ingredients, providing assay results consistent with the declared contents. The proposed CE method provides a simple, rapid, cost-effective, and environmentally friendly alternative for the routine quality control of pharmaceutical and cosmetic formulations containing AZA and SA. Full article

The complexity of micrometer-scale pore-throat structures in sandstone reservoirs strongly controls the occurrence state and mobilization degree of residual oil after water-flooding. To clarify the differences in residual oil occurrence between pure oil-zone and transition-zone reservoirs and their microscopic controlling mechanisms, sandstone samples were collected from the SII oil layer group, which belongs to the Upper Cretaceous Yaojia Formation, in the Nanqi area of the Daqing Oilfield, northern Songliao Basin, NE China, and were investigated. Mercury intrusion capillary pressure (MICP), two-dimensional nuclear magnetic resonance (2D NMR), laser scanning confocal microscopy (LSCM), micro-computed tomography (micro-CT), X-ray diffraction (XRD), wettability measurement and fractal analysis were integrated to systematically characterize the pore-throat architecture, mineral composition, seepage capacity, and residual oil occurrence of the two reservoir types. The results show that the pore-throat radius distributions are mainly unimodal. In the pure oil-zone samples, the pore-throat distribution is highly consistent with the corresponding permeability contribution curve, whereas evident deviations occur in some transition-zone samples. Large and medium pore throats exert the most significant control on seepage capacity, and the difference in fractal characteristics is mainly reflected by D1, the fractal dimension of large pore throats. The transition-zone reservoirs generally exhibit moderate to strong water-wet characteristics. Owing to the development of fine pore throats and strong capillary forces, water is prone to retention within pore-throat spaces, resulting in pronounced water-blocking and Jamin effects. After water-flooding, the pure oil-zone reservoirs exhibit lower residual oil saturation, with residual oil occurring mainly in a bound state; in contrast, the transition-zone reservoirs show higher residual oil saturation and relatively high proportions of free and semi-bound residual oil. Mineral composition further modifies pore-throat complexity and residual oil occurrence. D1 is negatively correlated with feldspar content, indicating that increased feldspar content helps improve the pore-throat structure, but positively correlated with clay mineral content, suggesting that clay minerals enhance structural complexity. In the transition-zone reservoirs, kaolinite and illite–smectite mixed-layer minerals are relatively well developed. Their velocity-sensitive and water-sensitive effects readily induce pore-throat blockage and increased flow resistance, which are important causes of residual oil enrichment and difficult oil mobilization in the transition zone. Full article

Polyhydroxyalkanoates (PHAs) are biodegradable microbial polyesters that may reduce dependence on petroleum-derived plastics, but broader use remains constrained by production costs and tightly controlled cultivation. Thermophilic microorganisms have attracted increasing attention as promising PHA producers because they can be cultivated at elevated temperatures, reducing contamination risks and operational costs. In this study, a thermophilic Geobacillus sp. strain SL28 isolated from a Vietnamese hot spring was evaluated for its PHA-producing capability. Temperature, initial pH, carbon and nitrogen sources, C/N ratio, and cultivation time were examined. Intracellular inclusions were assessed by Sudan Black B and Nile Blue A staining and transmission electron microscopy, whereas the recovered polymer was characterized by FE-SEM, Fourier-transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC–MS), ¹H- and ¹³C-nuclear magnetic resonance (NMR) spectroscopy, capillary viscometry, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing. Under the optimized cultivation conditions identified by one-factor experimentation (50 °C, pH 7.0, sucrose, peptone, C/N 25:1, and 72 h), SL28 reached a dry cell weight of 2.215 ± 0.16 g/L and a PHA concentration of 1.383 ± 0.04 g/L, equivalent to 62.57 ± 2.82% of DCW. Structural characterization confirmed that the recovered polymer was poly(3-hydroxybutyrate) (PHB). The purified PHB also exhibited favorable thermal stability, a relatively high molecular weight, and satisfactory mechanical properties. These results demonstrate the potential of thermophilic Geobacillus sp. SL28 as a promising candidate for PHB production. Full article