Search Results (17,447)

Carcinomas of the pancreas and bile duct remain highly lethal malignancies, with surgical resection representing the only potentially curative treatment. Despite improvements in perioperative mortality, postoperative complications remain frequent and negatively affect long-term outcomes. Recent evidence suggests that the pancreas and bile ducts harbor distinct microbial communities, challenging the traditional concept of sterility in these environments. However, their composition and clinical relevance remain incompletely understood. This study aimed to characterize microbiome profiles across different anatomical sites in patients undergoing pancreatic surgery, evaluate the impact of preoperative biliary stenting, and assess associations between prevalent bacterial species and postoperative outcomes. A total of 224 samples (bile, pancreatic fluid, duodenal tissue, tumor tissue, and healthy pancreatic tissue) from 58 patients with pancreatic cancer, bile duct cancer, chronic pancreatitis, or healthy pancreas were analyzed using 16S rRNA gene sequencing. Microbial diversity was assessed using the Shannon index for alpha diversity and nMDS with PERMANOVA for beta diversity. Distinct microbial profiles were identified across body sites, with significant beta-diversity differences between duodenal, bile, and pancreatic fluid samples and between duodenal and pancreatic fluid samples from the same patient. Preoperative biliary stenting significantly influenced microbial composition. Enterococcus faecalis was associated with a reduced risk of severe postoperative complications (Clavien–Dindo ≥ III). Overall, microbial composition varies across anatomical sites and disease entities, and specific bacteria may influence surgical outcomes, warranting further investigation in larger cohorts. Full article

In this study, we evaluated the biofilm-forming capacity of the B. pacificus B630 strain on table eggshells and its behavior in the presence of egg components, in comparison with B. cereus ATCC 14579. Strain B630, previously characterized as nhe⁺ and cytK⁺ and as a strong biofilm producer on glass, was confirmed as motile and positive for protease and phospholipase production. In static assays on disinfected eggshell pieces, B630 formed significantly more biofilm than ATCC 14579, while both strains exhibited comparable numbers of vegetative cells and spores embedded in the biofilm. Scanning electron microscopy and Fourier transform infrared (FT-IR) analysis revealed a dense extracellular matrix, altered eggshell crystal morphology, and a reduction in calcite-associated bands in biofilm-positive shells. In brain–heart infusion (BHI) broth supplemented with egg white, growth and spore germination of ATCC 14579 were strongly inhibited, whereas B630 displayed markedly higher tolerance. In an eggshell contamination model with an initial inoculum of 1 × 10⁵ colony-forming units, B630 persisted on the shell for at least 15 days at room temperature, while neither strain was recovered from egg white or yolk. These findings indicate that B. pacificus B630 combines robust biofilm formation with enhanced tolerance to egg white, favoring prolonged persistence on eggshells and underscoring the potential role of highly biofilm-forming B. cereus s.l. strains in table egg contamination. The persistence of strains of the B. cereus s.l. group in the eggshell may compromise the safety of the product. Full article

Carbon fiber-reinforced polyimide composites are critical for aerospace applications in high-temperature environments of 300–500 °C. However, conventional PMR-15- and PEPA-terminated polyimides are limited by their insufficient glass transition temperatures (T_g) and low crosslinking densities. This study proposes a reactive backbone construction strategy by employing 4,4′-(ethyne-1,2-diyl)diphthalic anhydride (EBPA) as a difunctional monomer copolymerized with asymmetric 2,3,3′,4′-biphenyl tetracarboxylic dianhydride (α-BPDA) and 4,4′-oxydianiline to synthesize polyimide resins containing both backbone ethynyl and terminal phenylethynyl groups. The effects of EBPA content on the curing behavior, thermomechanical properties, and elevated temperature mechanical performance were systematically investigated. The incorporation of EBPA significantly elevated T_g from 378 °C to 486 °C. Compared to the EBPA-0 control, the optimized EBPA-2 composite exhibited 7.3% and 3.6% improvements in room temperature flexural strength and modulus, respectively. Notably, at 400 °C, EBPA-2 demonstrated retention rates of 69.9%, 93.7%, and 61.6% for flexural strength, flexural modulus, and interlaminar shear strength, exceeding EBPA-0 by 16.9, 8.9, and 18.6 percentage points. SEM analysis confirmed the effective suppression of interfacial debonding at elevated temperatures. These findings elucidate the structure–property relationships between molecular structure, T_g, and short-term high-temperature mechanical retention, providing a promising resin matrix for advanced aerospace carbon fiber composites. Full article

The long-term durability of adhesive anchors in aggressive environments is a critical concern for infrastructure safety, with steel corrosion being one of the most detrimental phenomena. While glass fiber-reinforced polymer (GFRP) anchors offer corrosion-resistant alternatives to steel anchors in harsh marine environments, the bond performance at the anchorage interface progressively deteriorates under wetting–drying (WD) cycles, which may compromise long-term anchorage integrity. However, the bond characteristics of GFRP anchors under WD exposure, particularly the development of predictive models, remain insufficiently understood. This paper presents an experimental investigation into the impact of WD cycles on the bond of GFRP adhesive anchors in concrete. Twenty-four specimens were tested under pull-out loads, considering two key variables: bonded length (40 mm and 80 mm, corresponding to 5 and 10 times the bar diameter) and number of WD cycles (0, 30, 60, and 90). Artificial seawater was prepared via ASTM D1141-98 to simulate marine exposure conditions. The results revealed that both bond strength and bond stiffness decreased significantly with increasing WD cycles, while the failure mode progressively shifted from the bar–adhesive interface to the adhesive–concrete interface. Based on the experimental data, a cycle-dependent bond strength model was developed to predict the bond degradation of the anchor–concrete interface after WD exposure. Requiring only the undegraded concrete strength, the proposed model effectively captures the coupled effects of WD cycles and bonded length on bond strength degradation, presenting a practical tool for the durability design and service life evaluation of GFRP anchorage systems in coastal and marine environments. Full article

The development of sustainable encapsulation materials with tunable thermomechanical properties remains a critical challenge for photovoltaic reliability. Currently, the mainstream encapsulant for polycrystalline silicon solar cells is crosslinked EVA (Ethylene-Vinyl Acetate), which complicates the end-of-life recycling and reuse of modules. There is an urgent need to develop a novel encapsulant that combines excellent barrier properties with thermoplastic recyclability. Herein, we report a novel series of thermally decomposable CO₂-based thermoplastic polyurethane (PPC-TE) films engineered through the rational design of soft and hard segments. Utilizing polycarbonate diol (PPCDL) and polyether glycol (PEG) as soft segments, we systematically tailor material properties by modulating PEG-to-PPCDL ratios (5–20 wt%) and PEG molecular weights (1000–4000 g/mol). The optimized PPC-TE films exhibit excellent transmittance (>90%), adjustable glass transition temperature (T_g: 35.1 °C~11.6 °C), and remarkable mechanical adaptability (51~92 HA). The PPC-TE films exhibit water vapor permeability (WVP) as low as 14.8 g·mm·m⁻²·day⁻¹ and oxygen permeability (OP) of 4.13 cc·mm·m⁻² day⁻¹ at 15 wt% PEG content, surpassing commercial ethylene–vinyl acetate (EVA) encapsulants. Notably, these films demonstrate fully thermal decomposition above 350 °C, facilitating eco-friendly photovoltaic device recycling. Superior adhesion to glass substrates is evidenced by peel strengths up to 37 N/cm (PPC-TE2000-20) and the shrinkage rate is as low as 3%. This work contributes to improving the long-term stability of solar cells and has the potential for large-scale production. Full article

Objective: To study the prevalence and associated factors of digital eye strain among university students. Methodology: A cross-sectional survey and analytical study was conducted on 387 university students, ranging from 1st to 4th year, aged 18–23 years. The participants were digital device users who had not been medically diagnosed with any eye diseases affecting their use of digital devices. Statistical analyses were performed using the Descriptive Statistics, Chi-square test, and Fisher’s exact test. Results: The prevalence of digital eye strain among university students was found to be 80.40%. The most common symptoms were headache (80.62%), burning sensation in the eyes (75.19%), and eye pain (71.06%). The study found that 30.49% were male and 69.51% were female, with an average age of 20.07 ± 0.07 years. It was found that gender (p < 0.05, Phi = 0.14), vision problems (p < 0.05, Phi = 0.20), wearing light-filtering glasses (p < 0.05, Phi = 0.12), average daily smartphone screen time (p < 0.05, Phi = 0.19), avoiding digital devices before sleep (p < 0.05, Phi = 0.22), glare (p < 0.05, Phi = 0.19), wind exposure to the eyes (p < 0.05, Phi = 0.20), and ambient air conditions (p < 0.05, Phi = 0.15) were significantly associated with digital eye strain (p < 0.05); however, the strength of these associations was small (Phi = 0.12–0.22), indicating limited practical impact. Conclusions: Digital eye strain is highly prevalent among university students. Although several factors were statistically associated with digital eye strain, the small effect sizes suggest that each factor contributes only modestly. These findings highlight the multifactorial nature of digital eye strain and the importance of considering combined behavioral, environmental, and ergonomic influences. Full article

With the increasing application of novel glass materials in the field of optics, traditional empirical and trial-and-error approaches to glass development are gradually becoming insufficient to meet escalating performance demands. In this study, we propose a neural network-based machine learning method for the design of advanced fluoride glass materials. Predictive models for density and refractive index were first developed based on online fluoride glass datasets. Moreover, SHapley Additive exPlanations (SHAP) analysis was adopted to uncover the quantitative composition-property relationship. Then, the well-trained model was employed for inverse design, identifying specific compositions that fulfill desired properties in terms of density and refractive index. Finally, several recommended compositions were experimentally validated and the measured density and refractive index matched well with the corresponding input values, thereby confirming the effectiveness of the proposed method in designing new fluoride glass materials. Full article

Mechanical stress has been implicated in retinal pigment epithelium (RPE) dysfunction and angiogenic signaling in retinal disorders; however, its direct in vivo effects on the RPE–choroid complex remain incompletely understood. Here, we established a mouse model of localized mechanical stress by subconjunctival implantation of glass beads (0.8–1.2 mm in diameter) in eight-week-old C57BL/6J mice to induce transscleral stretching of the RPE. Ocular tissues were analyzed two days after implantation using histological, immunohistochemical, and molecular approaches, and inflammatory mediators were quantified by multiplex cytokine assays. Mechanical stress induced focal serous retinal detachment, elongation of photoreceptor outer segments, and disruption of the RPE tight junction protein ZO-1. VEGF expression in the RPE–choroid complex was significantly upregulated and accompanied by increased levels of inflammatory mediators, including MCP-1. Intravitreal administration of anti-VEGF agents effectively suppressed stress-induced VEGF expression. These findings indicate that mechanical stress is sufficient to induce structural disruption and angiogenic signaling in the RPE in vivo, providing a useful experimental platform for investigating stress-related retinal responses and therapeutic modulation of VEGF signaling. Full article

Glass preheating prior to laser scanning is expected to enhance internal modification morphology; however, its effect on weld seam topology and welding strength have not been investigated. In the current work, the effects of preheating on ultrafast laser (184 fs and 10 ps) internal modification and welding strength of borosilicate glass slides are investigated. For the internal modification experiments, pulse energy of 30–100 µJ and repetition rate of 10 kHz are used by focusing a laser beam at the interface of optically contacted slides at room temperature (RT ≈ 23 °C), 150 and 200 °C. Welding is conducted by a pulse energy of 4.5–18 µJ and repetition rate of 200 kHz using pre-clamped glass slides with a scanning speed of 10 mm/s at RT and 150 °C. Also, for welding, the optimum number of scans and hatching spacing are identified. Filamentation experiments show that discoloration is not significant when preheat temperature reaches 200 °C. Compared to 10 ps, pulse duration of 184 fs can produce a 19% narrower plasma-modified region at both RT and 150 °C and a 13% wider heat-affected zone at 150 °C. Welding using optimum conditions of 5 scans and 200 µm hatch, and “crack-free” laser parameters produces an average strength of: 50 ± 3.2 MPa at RT and 40 ± 2 MPa at 150 °C for 184 fs compared to 35 MPa at RT and 32 MPa at 150 °C for 10 ps, using 10 replicates each. However, the welding strength upon preheating to 150 °C using 184 fs is still 25% higher compared to average reported laser welding bonding strength, while the 10 ps strength is within the reported average. The enhanced welding strength for 184 fs can be attributed to reduced microcracking, especially when “crack free” combinations are utilized. Full article

Dissemination and conservation of cultural heritage have been challenged by continued accessibility in museums, where traditional information delivery systems are at times ineffective in terms if interaction with visitors. The current paper investigates RumiArt IA, a mobile application, to identify cultural objects in real-time, remaining fully in the scope of this line of research without relying on internet connectivity. The system, which is developed based on the Rumiñahui Museum and Cultural Center, Ecuador, uses transfer learning in the MobileNetV2 architecture with INT8 post-training quantization to identify 21 cultural artifacts spread across six thematic rooms. The experiment involved building a dataset of 36,000 images under diverse lighting conditions, viewing angles, and distances; furthermore, artificial transformations were explicitly crafted to simulate real museum conditions such as glass reflections and non-frontal capture angles. Quantization was used to reduce each model to 775 KB as compared with the 2.4 MB, with accuracy loss not reaching more than 0.5 percent (DKL < 0.05). Assessment of 9450 validation images yielded a general accuracy of 92.2%, with an inference time of 63 ms on current devices with a high throughput and 215 ms on mid-range hardware from 2020. Practical validation involving 50 visitors of the museum showed a success rate of 93.7%, with average user satisfaction at 8.5/10 and 87%, indicating they would recommend the application. An in-depth error study of the most difficult room (88.3% accuracy) indicated that 47% of the errors were due to the angles of the camera, which blocked out distinguishing features, and 22% were caused by display case reflections and the shadows of the visitors. These results indicate that end-to-end machine learning can provide consistent cultural heritage recognition in resource-constrained settings but its efficiency is susceptible to physical capture factors that cannot be resolved by data augmentation. Offline mode and low memory footprint (less than 90 MB when loaded on six models) of the system are especially relevant to application in situations where there is no guarantee of cloud connectivity. Full article

Epoxy-glass-mica composite materials are widely used as electrical insulating materials in high-voltage rotating machinery due to their layered structure and excellent dielectric properties. Taking the F-class epoxy glass with a small amount of rubber powder mica tape commonly used as the main insulation of wind turbine stator coils as the research object, 7-day, 14-day, 21-day, and 28-day low-temperature treatment tests were conducted at −50 °C. The surface morphology and chemical structure changes of the materials were characterized by SEM and FTIR, and the influence laws of low-temperature treatment on the electrical properties of the mica tape insulation materials were systematically studied. The experimental results show that the low-temperature environment will induce microcracks and interface delamination and other structural damages, but no obvious change in the chemical structure of the mica tape was observed. With the extension of the low-temperature treatment time, the electrical properties of the mica tape show a deteriorating trend, and after 28 days of low-temperature treatment, the breakdown field strength of the F-class mica tape decreased by approximately 18.5%, and the volume conductivity overall increased by about two orders of magnitude. This indicates that the microcrack defects induced by low-temperature will lead to an enhanced electrical-thermal coupling effect in the insulation structure, thereby accelerating the degradation process of the insulation material. This reveals the degradation mechanism of wind turbine stator main insulation from “structural damage” to “performance degradation” and then to “insulation aging” under low-temperature conditions, providing a theoretical basis for the design and reliability assessment of insulation systems in wind turbine generators in cold regions. Full article

In order to investigate the effects of bentonite and glass fiber on the macroscopic mechanical properties and microscopic mechanisms of cement soil in dry environments, a series of laboratory tests were conducted in this study, including drying tests under controlled environments (30 °C, 50% humidity), unconfined compressive strength (UCS) tests, digital image processing technology, and scanning electron microscopy (SEM) analyses. The moisture evaporation law, surface crack development process, UCS variation, and microstructure evolution of cement soil with different mix proportions (bentonite content: 0–9%; glass fiber content: 0–0.5%) were systematically analyzed. The results show that bentonite can significantly enhance the water retention capacity of cement soil, reduce the water evaporation rate, and increase the unconfined compressive strength by filling internal pores to densify the microstructure. Glass fibers form a three-dimensional network structure in the matrix, exerting a bridging effect to inhibit crack initiation and propagation, and optimize the mechanical properties. The unconfined compressive strength increases significantly with an increase in bentonite content (3–9%), and the optimal fiber content for strength improvement is determined as 0.3%. The synergistic effect of bentonite and fibers optimizes the interfacial bonding force between fibers and the matrix, which remarkably improves the anti-cracking performance of cement soil. Specifically, when the bentonite content is 6–9% and the fiber content is 0.3–0.5%, the cement soil maintains complete integrity after drying, with no obvious cracks on the surface. SEM analysis reveals that the addition of bentonite and fibers inhibits the expansion and connection of internal voids, avoiding the cycle of “void enlargement–stress concentration–crack propagation”. This study provides a scientific basis for the engineering application of cement soil in a dry environment. Full article

The clinical effectiveness of clear orthodontic aligners mainly depends on the thermomechanical stability of the polymers in this challenging hydrothermal environment. In this study, we compare the water-induced viscoelastic changes and glass transition temperature (Tg) stability of four polymers with different microarchitectures. Specifically, we examined directly printed photopolymer networks (Tera Harz TC-85 and LuxCreo 4D Aligner), a monolithic thermoplastic (Duran+), and a multilayer thermoplastic (ClearCorrect). Samples were immersed in physiological saline (0.9 wt.% NaCl) at 37 °C for 7 days, and Dynamic Mechanical Analysis (DMA) was performed in three conditions: dry, after immersion, and after a 2 h desorption step, mimicking a typical clinical 22:2 wear cycle. All polymers showed a decrease in Tg after immersion, with TC-85 exhibiting the greatest reduction relative to the dry baseline. Tg recovery after a 2 h ambient desorption step was incomplete and was significantly associated with the amount of water retained after 2 h drying (expressed as % of initial uptake; R² = 0.419), whereas total water absorption after 7 days was not associated with short-term thermal recovery. Full article

Since 2007, the porosity–to–cement relationship has been widely used as a unified parameter to predict mechanical strength, durability, expansion, and stiffness of stabilized soils. In this formulation, the volumetric binder content is adjusted by an internal exponent x, typically ranging between 0 and 1, to balance the relative contributions of porosity and cementation. Traditionally, the parameters of this relationship have been obtained using manual regression procedures. This study proposes an automated calibration methodology for the porosity–binder index, where the parameters A, B, and x are determined through an iterative optimization framework based on minimization of the sum of absolute errors (SAE) combined with a Monte Carlo search algorithm. The methodology is applied to a cement-stabilized clay blended with ground glass (GG), recycled gypsum (GY), and limestone residues (CLW). The predictive capability of the calibrated model is evaluated using unconfined compressive strength (q_u) and initial shear stiffness (Go) datasets. Two calibration strategies are considered: Calibration Process No. 1, based on CLW mixtures and q_u values only, and Calibration Process No. 2, incorporating all mixtures (CLW, GG, and GY) and both q_u and Go responses. The results indicate that Calibration Process No. 2 provides a more robust and physically consistent parameter set, yielding coefficients of determination of 0.9318 and 0.9412 for q_u and Go, respectively. The proposed algorithm-driven calibration framework improves predictive capability and provides a systematic approach for determining the parameters of the porosity–binder relationship. Full article

Amorphous metallic materials have emerged as a promising class of functional materials for energy storage and conversion owing to their disordered atomic structure and unique interfacial properties. This review focuses on amorphous metals and alloys, including metallic glasses and high-entropy amorphous systems, with particular emphasis on their surface- and interface-driven behavior in electrochemical environments. This review analyzes how structural disorder influences key properties such as electronic structure, ion transport, catalytic activity, and mechanical compliance and how these factors govern performance in batteries, supercapacitors, electrolyzers, and fuel cells. Special attention is given to interfacial phenomena, including charge-transfer kinetics, corrosion and passivation processes, and structural evolution during long-term operation. In addition, recent advances in fabrication strategies such as rapid solidification, thin-film deposition, mechanical alloying, thermoplastic forming, and electrodeposition are discussed in relation to their ability to tailor amorphous structures and interfaces. This review also highlights critical failure mechanisms and discusses some strategies to mitigate these effects. Overall, this work provides a focused perspective on the role of amorphous metallic surfaces and interfaces in electrochemical systems, identifying current challenges in scalability, durability, and compositional control, and outlining future directions for their integration into next-generation energy technologies. Full article