Search Results (1,941)

Chronic kidney disease (CKD) is a progressive disorder that is characterized by the gradual loss of kidney function, often leading to end-stage renal failure. Recent research has highlighted the role of gut dysbiosis and its metabolic byproducts in the pathogenesis of CKD, with a particular focus on short-chain fatty acids (SCFAs). SCFAs, including acetate, propionate, and butyrate, are primarily produced by the fermentation of dietary fibers by the gut microbiota and are known for their systemic anti-inflammatory and immunomodulatory properties. In CKD, gut dysbiosis results in a reduction in SCFA-producing bacteria and an increase in uremic toxin-producing microorganisms, contributing to systemic inflammation, oxidative stress, and renal fibrosis. The depletion of SCFAs has been shown to exacerbate glomerular injury, whereas their presence supports integrity of the glomerular barrier and confers protection against damage. These protective effects are mediated by several mechanisms, including the modulation of immune responses, preservation of epithelial barrier function, and activation of specific receptors, such as G protein-coupled receptor 41 (GPR41), GPR43, and GPR109A. The present review provides a comprehensive overview of current understanding of SCFA-mediated pathways in glomerular protection during CKD progression. It highlights the therapeutic potential of targeting the gut–kidney axis to mitigate CKD progression by examining the complex interplay between gut microbiota and disease development, with a particular focus on strategies to protect the glomerular structure and function. Full article

Background and Objectives: The study aims to evaluate the effects of regular physical activity on ocular structures by comparing eye anterior segment structures and retinal nerve fiber layer (RNFL) parameters between elite individual athletes and sedentary persons. Materials and Methods: This cross-sectional observational study included 75 participants (33 female and 42 male) aged 18–32 years. Participants consisted of 33 elite individual athletes (66 eyes) aged 18–32 years and 42 sedentary individuals (84 eyes) aged 18–28 years. The elite athlete group consisted of participants who had trained ≥ 3 times per week for the past 5 years and had competition experience in tennis (n = 11), badminton (n = 8), and short/middle distance running (n = 14). Sedentary participants had not engaged in regular physical activity for the last 2 years. Anterior segment structures were measured with ultrasound biomicroscopy (UBM), RNFL parameters were measured with spectral-domain optical coherence tomography (SD-OCT), and intraocular pressure (IOP) was measured with a non-contact pneumotonometer. Results: When the anterior segment parameters were compared, a significance was found in the group effect (p = 0.021, ${ƞ}_p^2$ = 0.036) in the TIA500 value, but the effects of side and gender were insignificant (p > 0.05). While the gender effect was found to be significant for the AOD500 (p = 0.030, ${ƞ}_p^2$ = 0.032) and ARA500 (p = 0.019, ${ƞ}_p^2$ = 0.038) variables, the group and side effects were statistically insignificant (p > 0.05). There was a significant difference in IOP values between sedentary individuals (15.82 ± 2.69) and athletes (14.61 ± 1.80) (p = 0.004, ${ƞ}_p^2$ = 0.057). There was a significant difference between the right (15.71 ± 2.70) and left (14.87 ± 2.02) sides (p = 0.027, ${ƞ}_p^2$ = 0.033). The effect of gender was not significant (p > 0.05). When the results were evaluated, a significant effect of the TEMPORAL side in RNFL parameters (p = 0.003, ${ƞ}_p^2$ = 0.058) was observed. Correlations were seen between the anterior segment and RNFL parameters in both groups (p < 0.05). Conclusions: Athletes exhibited lower IOP compared with sedentary individuals, with similar RNFL parameters but distinct correlation patterns with anterior segment structures. These findings suggest that ocular parameters should be evaluated in an integrated manner and that physical activity may support ocular health by contributing to IOP reduction and potentially slowing the progression of eye diseases. Full article

This study investigates the potential of corn stover, an abundant agricultural byproduct, as a sustainable additive in concrete masonry units (CMUs). Preliminary trials were conducted to determine the optimal fiber length (~3 mm and ~10 mm), fiber content (0%, 1%, 3%, and 5% by volume), and alkalinization method (soaking in 0.5 M NaOH, KOH, or synthetic concrete pore solution) for corn stover fibers (CSFs). The results indicated that short fibers treated with synthetic concrete pore solution yielded the best compressive strength and workability, and were thus selected for the main study. A novel mixture was developed by replacing 10% of cement with corn stover ash (CSA) and incorporating 1% alkaline-treated CSF by volume. The resulting blocks (termed “Corncrete”) were evaluated for mechanical and durability properties, including strength, water absorption, bulk and surface electrical resistivity, rapid chloride permeability (RCPT), and fire resistance. Compared to conventional CMUs, Corncrete exhibited an 11–13% reduction in 28- and 91-day compressive strength, though the difference was statistically insignificant. Physically, Corncrete had a 4.4% lower bulk density and a 7.9% higher total water absorption compared to the control. However, its water absorption rates at early stages were 32% and 48% lower, indicating better resistance to moisture uptake shortly after exposure. Durability tests revealed a 13.7% reduction in chloride ion permeability and a 33% increase in bulk and surface electrical resistivity after 90 days. Fire performance was comparable between the two mixtures, with both displaying ~10.5% mass loss and ~5% residual strength after high-temperature exposure. These findings demonstrate that Corncrete offers balanced mechanical performance and enhanced durability, making it a viable eco-friendly option for non-structural masonry applications. Full article

This randomized, double-blind, controlled trial evaluated the effects of 4-week dietary fiber supplementation on gut microbiota, bowel-related quality of life, and secondary outcomes, including sleep and skin condition. A total of 105 healthy adults received either low-fiber foods (2.2 g/day total fiber, 1.2 g/day fermentable fiber) or high-fiber foods (8.2 g/day total fiber, including 6.4 g/day fermentable fiber). Gut microbiota was analyzed by 16S rRNA sequencing. Outcomes included stool diary, JPAC-QOL (Japanese version of the Patient Assessment of Constipation Quality of Life), OSA-MA (Oguri-Shirakawa-Azumi sleep inventory MA version), skin questionnaires, and fecal organic acids. The high-fiber group showed significant improvements in JPAC-QOL and increases in SCFA-associated genera such as Anaerostipes, Bifidobacterium, and Fusicatenibacter. These taxa positively correlated with other beneficial bacteria, including Faecalibacterium, suggesting ecological cooperation. The effects on sleep and skin were limited but correlated with beneficial bacteria, implying possible gut–brain and gut–skin axes involvement. This study demonstrated that short-term fiber supplementation meaningfully improved the bowel-related quality of life and beneficially modulated the gut microbiota in healthy adults. Although the systemic effects were modest, microbial shifts suggest that higher fiber intake may provide broader health benefits with longer interventions. This study was registered in the UMIN Clinical Trial Registry (UMIN000054712). Full article

This work presents a proof of concept for a short-range high spectral resolution lidar (SR-HSRL) optimized for aerosol characterization in the first kilometer of the atmosphere. The system is based on a compact, high-repetition-rate diode-based fiber laser with a 300 MHz linewidth and 5 ns pulse duration, coupled with an iodine absorption cell. A central challenge in the instrument’s development was identifying a laser source that offered both sufficient spectral resolution for HSRL retrievals and nanosecond pulse durations for high spatiotemporal resolution, while also being compact, tunable, and cost-effective. To address this, we developed a methodology for complete spectral and temporal laser characterization. A two-day field campaign conducted in July 2024 in Tsukuba, Japan, validated the system’s performance. Despite the relatively broad laser linewidth, we successfully retrieved aerosol backscatter coefficient profiles from 50 to 1000 m, with a spatial resolution of 7.5 m and a temporal resolution of 6 s. The results demonstrate the feasibility of using SR-HSRL for detailed studies of aerosol layers, cloud interfaces, and aerosol–cloud interactions. Future developments will focus on extending the technique to ultra-short-range applications (<100 m) from ground-based and mobile platforms, to retrieve aerosol extinction coefficients and lidar ratios to improve the characterization of near-source aerosol properties and their radiative impacts. Full article

The gut microbiome has emerged as a critical determinant of immune-checkpoint inhibitor (ICI) efficacy. A narrative review of 95 clinical studies (2015–2025) shows that patients with greater gut microbial diversity and relative enrichment of commensals such as Akkermansia, Ruminococcus, and other short-chain fatty acid producers experience longer progression-free and overall survival, particularly in melanoma and non-small-cell lung cancer. Broad-spectrum antibiotics given within 30 days of ICI initiation and over-the-counter mixed probiotics consistently correlate with poorer outcomes. Early phase I/II trials of responder-derived fecal microbiota transplantation in ICI-refractory melanoma achieved objective response rates of 20–40%, while pilot high-fiber or plant-forward dietary interventions improved immunologic surrogates such as CD8⁺ tumor infiltration. Machine-learning classifiers that integrate 16S or metagenomic profiles predict ICI response with an area under the ROC curve of 0.83–0.92. Methodological heterogeneity across sampling, sequencing, and clinical endpoints remains a barrier, underscoring the need for standardization and larger, well-powered trials. Full article

Inhalation of multi-walled carbon nanotubes (MWCNTs) poses potential health risks due to their structural similarity to asbestos and their ability to induce chronic lung inflammation, fibrosis, and lung cancer in animal models. This study investigated the pulmonary inflammatory and transcriptomic responses of two distinct MWCNTs—NM-401 (long, rigid) and NM-403 (short, thin)—in rats and mice using intratracheal instillation at matched dose levels at two post-exposure time points. Both MWCNTs induced acute neutrophilic inflammation and dose-dependent transcriptomic alterations in both species, with NM-403 eliciting a stronger response. Transcriptomic profiling revealed a substantial overlap in differentially expressed genes across materials and species, particularly at the early time point. Fibrosis-associated genes were upregulated in both species, with more persistent expression observed in rats. Acute phase response genes, including Orosomucoid 1 and Lipocalin 2 were commonly induced, while Serum Amyloid A3 and Orosomucoid 2 were selectively upregulated in mice. Functional enrichment analyses showed conserved activation of immune and inflammatory pathways. Our findings show that even short, non-fiber-like MWCNTs can provoke potent and persistent pulmonary effects, challenging assumptions based solely on MWCNT properties. Despite differences in long-term responses, the overall inflammatory and transcriptional profiles showed strong interspecies concordance, suggesting that both rats and mice are relevant models for assessing MWCNT-induced pulmonary toxicity. Full article

To meet the increasing performance requirements of drilling pipes, including a reduced weight and enhanced mechanical and thermal properties, the application of aluminum alloys must be further advanced. Short-carbon-fiber-reinforced 2A12 aluminum alloy composites were fabricated via powder metallurgy. The density, hardness, and tensile strength of the composites were measured. The influence of the carbon fiber content on the composite’s mechanical properties was investigated across various temperatures. The composite material exhibited maximum yield strengths of 412 MPa at room temperature, 381 MPa at 180 °C, and 337 MPa at 220 °C. Incorporating carbon fibers increased the service temperature of a 2A12 aluminum alloy by approximately 40 °C. The strength increment of composites with a fiber content below 6 vol.% corresponded to the load transfer mechanism of carbon fiber, while the reason for non-conformity at a more than 6 vol.% fiber content was the continuous fracturing of carbon fibers, leading to the failure of the composites. Full article

The global insect farming sector is rapidly expanding, driven by rising demand for sustainable protein sources and its potential to contribute to food security solutions. This study focuses on the quantification of chitin by comparing two gravimetric methods (ADF-ADL and crude fiber estimation) with a purification method considered as a reference method. It also aims to use the near-infrared spectroscopy (NIRS) to rapidly assess the quality of insect meals, in particular the macronutrients (moisture, protein, fat) and chitin content in a large data set of insect samples. Both alternative methods overestimated chitin content compared to the enzymatic purification method, which is the most reliable but more complex and expensive. Given their advantages (fairly simple, no significant investment, higher sample throughput, relatively short time execution), they can serve for rapid screening when precise chitin determination is not required. Calibration models showed good performance, particularly for protein and fat determination, and satisfactory results for chitin prediction. The NIRS models show promises for rapid and reliable prediction of insect products, although the chitin assessment remains to be further validated. Its implementation could streamline chemical quality control in insect-based food and feed production, offering speed and flexibility for industrial applications. Full article

Carbon fiber-reinforced composites (CFRCs) are widely used in aerospace, automotive, and defense applications due to their high strength-to-weight ratio and excellent mechanical performance. In this study, cores and sandwich panels were fabricated via fused filament fabrication (FFF) using co-polyester filaments reinforced with 20 wt.% short carbon fibers. The mechanical response of the structures was evaluated under low-velocity impact (LVI) conditions using instrumented drop weight testing at energy levels ranging from 2 to 20 J. A three-factor, three-level full factorial experimental design was employed, considering build orientation (flat vs. upright), infill pattern (trihexagonal vs. triangular), and impact energy as factors. The maximum contact force was selected as the primary response variable. The results revealed that upright-printed specimens exhibited significantly improved impact resistance compared to flat-printed ones, with increases in peak force of up to 28% for cores and over 68% for sandwich structures. Among the tested infill geometries, the triangular pattern outperformed the trihexagonal one across all configurations and energy levels. The combination of upright orientation and triangular infill proved to be the most effective, providing enhanced energy absorption and reduced rear-side damage, especially under higher impact energies. These findings offer valuable insights into the design of lightweight, impact-resistant structures produced by additive manufacturing, with direct implications for structural components in demanding engineering environments. Full article

The human gut microbiota is a complex ecosystem that influences host metabolism, immune function, and cardiovascular health. Dysbiosis, defined as an imbalance in microbial composition or function, has been linked to the development and progression of atherosclerosis. This connection is mediated by microbial metabolites that enter the systemic circulation and interact with vascular and immune pathways. Among these, trimethylamine N-oxide (TMAO) has been most extensively studied and is consistently associated with cardiovascular events. Other metabolites, including lipopolysaccharides (LPS), short-chain fatty acids (SCFAs), and secondary bile acids, also contribute by modulating inflammation, endothelial function, and lipid metabolism. Recent research has expanded to emerging metabolites such as indoxyl sulfate, indole-3-propionic acid, and polyamines, which may provide additional mechanistic insights. These microbial products are increasingly explored as biomarkers of cardiovascular risk. TMAO has shown predictive value in large human cohorts, while microbiota composition and diversity measures remain less consistent across studies. However, interpretation of these biomarkers is limited by methodological variability, interindividual differences, and lack of standardization. Therapeutic interventions targeting the gut–heart axis are under investigation. Dietary strategies such as the Mediterranean diet and fiber-rich nutrition, probiotics and prebiotics, and fecal microbiota transplantation (FMT) show promise, while pharmacological approaches targeting TMAO or bile acid pathways are in early stages. This review summarizes current knowledge on the mechanistic, diagnostic, and therapeutic links between the gut microbiota and atherosclerosis, highlighting both established findings and emerging directions for future research. Full article

The present study investigates the tensile properties of 3D-printed PA12 composites reinforced with short carbon fibers, focusing on the impact of printing parameters on material performance. We employed both experimental testing and machine learning-based predictive modeling to evaluate the influence of layer thickness, extrusion width, and raster angles on failure stress, failure strain, and stress–strain curves. Four machine learning models, including Gaussian process regression (GPR), gradient boosting regression (GBR), random forest (RF), and artificial neural network (ANN), were developed and trained on the experimental data. The results indicated that ANN and GPR models outperformed RF and GBR in predicting mechanical properties, with ANN demonstrating the highest accuracy across all tasks. A SHAP analysis was conducted to interpret the models, revealing that raster angles significantly influence failure stress predictions, while extrusion width predominantly affects failure strain predictions. The ability of the models to predict entire stress–strain curves provides a comprehensive understanding of the material’s mechanical behavior, which is crucial for applications requiring detailed material response data. This study highlights the potential of machine learning models, particularly ANN, in predicting the tensile properties of 3D-printed composites. The findings offer valuable insights for optimizing the 3D printing process to achieve desired material characteristics and pave the way for further research in integrating these predictive tools into additive manufacturing workflows for real-time optimization and quality control. Full article

The paper industry is always looking for possible solutions for new fiber-based products, such as protective and cushioning materials. These materials must be carefully designed to provide effective cushioning while also being lightweight to reduce transportation costs. Additionally, they need to offer protection from environmental and mechanical damage, besides having good processability to ensure proper buffering. The widely used protective and cushioning materials, such as plastic foams and expanded or extruded polystyrene, create significant disposal challenges. Therefore, there is increasing demand for biodegradable and sustainable materials for cushioning applications. The focus of our research was to develop fiber-based foams and investigate the influence of different compositions (hardwood and softwood) of cellulose fibers on the basic (mass, thickness, density) and mechanical properties (three-point bend test, tensile properties). Foams made entirely from short eucalyptus fibers (100S) exhibited the highest density (28.0 ± 0.34 kg/m³) and lowest thickness (38.82 ± 4.21 mm), resulting in superior tensile strength and elastic modulus but lower strain at break. In contrast, foams composed of long spruce fibers (100L) had the lowest density (19.0 ± 0.27 kg/m³) and highest thickness (58.52 ± 1.50 mm), with lower strength and stiffness but much higher ductility and porosity (confirmed by ~30% higher air permeability compared to 100S). Blended formulations demonstrated intermediate behavior, with the 50S50L foam showing a favorable balance of strength, stiffness, and flexibility. Visual analysis confirmed heterogeneous fiber distribution with localized agglomerates and compaction at the bottom layer due to casting. To further interpret the complex relationships within the dataset and uncover patterns, Principal Component Analysis (PCA) was applied to all experimental results. The findings of the research contribute to the broader understanding of how different fiber types and blends impact the performance of sustainable cellulose-based foams, with potential implications for the development of biodegradable packaging and lightweight construction materials. Full article

High-strength bolts play an essential role in connecting steel structural components across bridges, buildings, and machinery, thanks to their low cost and broad adaptability. However, prolonged exposure to complex loading and harsh environments can cause loosening, which increases the risk of structural distortion or catastrophic collapse. Conventional monitoring tools, such as strain gauges or fiber-optic sensors, often suffer from high expense, short service life, and poor early-warning performance. To overcome these challenges, this study presents a novel surface-mounted piezoelectric sensor built on lead magnesium niobate–lead titanate (PMN-PT) single crystals, selected for their superior piezoelectric constants, energy density, and low-frequency sensitivity. The sensor integrates a PMN-PT wafer, monolithic washer, epoxy resin encapsulation, and shielded cabling. It was experimentally validated through waterproofing and electrical tests across five working conditions, maintaining capacitance stability within 3.25% and infinite insulation resistance. Preload monitoring experiments were conducted using a time-reversal method, and a tightening index based on focused signal amplitude was proposed to quantify bolt-loosening conditions. Results confirmed a strong linear association (R² = 0.986) between the focused signal amplitude and preload torque (0–120 N·m), with a maximum error of only 5.7% in validation trials under unknown torque. Overall, this PMN-PT-based sensor offers a cost-efficient, sensitive, and durable solution for early detection of bolt loosening in steel structures. Full article

This paper provides an in-depth analysis of the microstructural characteristics and the chemical content of Polybutylene Terephthalate (PBT) composites that have different contents of Glass Fiber (GF). Blending of VALOX 420 (30 wt% GF/PBT) with unreinforced VALOX 310 allowed the composites to be prepared, with control of the concentration and distribution of the GF. The GF reinforcement and PBT matrix were characterized by an advanced microstructural spectrum and spatial analysis to show the influence of fiber density, dispersion, and chemical composition on performance. Findings indicate that GF content has a profound effect on microstructural properties and damage processes, especially traction effects in various regions of the specimen. These results highlight the significance of accurate control of GF during fabrication to maximize durability and performance, which can be used to inform the design of superior PBT/GF composites in challenging engineering applications. The implications of these results are relevant to a number of high-performance sectors, especially in automotive, electrical, and consumer electronic industries, where PBT/GF composites are found in extensive use because of their outstanding mechanical strength, dimensional stability, and thermal resistance. The main novelty of the current research is both the microstructural and chemical assessment of PBT/GF composites in different fiber contents, and this aspect is rather insufficiently studied in the literature. Although the mechanical performance or macro-level aging effects have been previously assessed, the Literature usually did not combine elemental spectroscopy or spatial microstructural mapping to correlate the fiber distribution with the damage mechanisms. Further, despite the importance of GF reinforcement in achieving the right balance between mechanical, thermal, and electrical performance, not much has been conducted in detail to describe the correlation between the microstructure and the evolution of damage in short-fiber composites. Conversely, this paper will use the superior spatial elemental analysis to bring out the effects of GF content and dispersion on micro-mechanisms like interfacial traction, cracking of the matrix, and fiber fracture. We, to the best of our knowledge, are the first to systematically combine chemical spectrum analysis with spatial mapping of PBT/GF systems with varied fiber contents—this allows us to give actionable information on material design and optimized manufacturing procedures. Full article