Search Results (4,068)

Accurate identification and enumeration of microscopic particles are important for microfluidic analysis, electrokinetic studies, and microscopy-based characterization of microfabricated systems. This study presents an optimized Hough Circle Transform (HCT) workflow for automated particle detection, sizing, and counting. Gold interdigitated electrode arrays (IDEAs) were fabricated on wafer substrates to generate electroosmotic flow, and 3 μm and 5 μm polystyrene microbeads were used as model particles. The final workflow incorporates parallelized multicore parameter optimization and composite statistical metrics based on detection accuracy and frame-to-frame standard deviation, enabling a small manually counted calibration set to be converted into locked detection parameters. In the final validation workflow, 10 manually counted calibration frames were used to optimize HCT parameters for each of four scenarios, and the locked parameters were then validated on 50 new frames per scenario (200 validation frames total) with two independent annotators. Mean validation success rates were 85.1% for 3 μm beads, 90.0% for 5 μm beads, 86.1% for 3 μm beads in mixed suspensions, and 87.2% for 5 μm beads in mixed suspensions, corresponding to object-level error rates of 17.9%, 10.9%, 19.9%, and 13.7%, respectively. Compared with the historical Generation I serial workflow, the optimized workflow reduced parameter-selection time from 24–48 h to 1–2 h, and the runtime image-processing time was approximately 45 ms per frame during offline analysis. These results show that parameter optimization is essential for robust HCT-based particle enumeration and that the workflow provides a practical analytical tool for microfluidic device characterization and electrokinetic experiments. Full article

Although microbial remediation is a promising strategy for PAH pollution control, its field application remains a significant challenge. PAH-degrading microbial consortia were enriched from contaminated sites in Nanjing. High-throughput sequencing was applied to analyze the community structure and functional characteristics of bacteria and fungi, and the phenanthrene degradation performance of free consortia and sodium alginate-activated carbon-immobilized composite beads was systematically evaluated. Results showed that the distance from the pollution source was the key factor driving the differentiation of microbial community structure. For bacteria, sites closer to the pollution source showed significantly lower bacterial diversity and richness, while an opposite trend was observed for fungi. Proteobacteria (40–87%) and Ascomycota (51–88%) were the dominant phyla of bacterial and fungal communities, respectively. Despite significant differences in genus-level community composition among samples, the functional gene abundance related to PAHs metabolism was highly similar across all consortia. The immobilized composite beads achieved a significantly higher phenanthrene degradation efficiency (94.70–99.26%) compared with free consortia (65.84–85.78%). The embedding material had a significant effect on degradation performance, while nutrient sources showed no significant impact on the degradation efficiency. This study provides theoretical support for the application of immobilized microbial technology in PAH-contaminated site remediation. Full article

Electrospinning is a relatively simple and promising method for producing polymeric, ceramic, and composite fibers, with diameters ranging from several nanometers to several micrometers. In this study, the influence of PVA solution concentration, tip-to-collector distance, and needle gauge at a constant applied voltage on the morphology and diameter of the electrospun fibers was investigated to optimize conditions for the production of bead-free nanofibers. PVA solutions with concentrations of 5, 7.5, and 10 wt.% were electrospun under varying processing conditions, and the resulting fibers were characterized by SEM. The results demonstrated a strong dependence of fiber morphology on polymer concentration. Low-concentration solutions (5 wt.%) produced fibers with significant bead formation, while increasing the concentration to 10 wt.% resulted in smooth and homogeneous fibers. A non-linear dependence of fiber diameter on tip-to-collector distance was observed, with 140 mm identified as the optimal distance for producing the thinnest fibers. Needle gauge also affected fiber morphology and process stability. The G22 needle produced finer fibers at the optimal collector distance of 140 mm, with the narrowest fiber diameter distribution, indicating the highest uniformity, whereas the G20 and G21 needles exhibited the broader distribution. Statistical analysis (ANOVA) confirmed the significance of the investigated parameters. These findings demonstrate that collector distance and needle gauge should not be evaluated independently and provide practical guidance for optimizing electrospinning conditions for the fabrication of uniform, bead-free PVA nanofibers. Full article

In this study, sodium alginate/inulin (SA/IN) composite beads were fabricated using the calcium ion cross-linking method, which encapsulated Lactobacillus plantarum to provide it with resistance in a gastrointestinal environment. The results showed that the SA/IN solution functioned as a kind of pseudoplastic fluid, and the storage modulus (G′) and loss modulus (G″) values exhibited a trend of frequency dependence. The diameter, water content, swelling rate, water holding capacity (WHC), and hardness of the composite beads were regulated by IN concentration, with IN making the beads rougher at first and then giving them a more regular shape as the concentration increased. The highest Lactobacillus plantarum encapsulation efficiency reached 92.8 ± 4.14%, and SA/IN beads improved the stability of Lactobacillus plantarum under 4 °C storage and heat treatment. The quantity of Lactobacillus plantarum reached 1.3 ± 0.01 CFU/g, which is close to the quantity observed before digestion. This study confirmed that SA/IN composite beads can serve as a protective carrier of Lactobacillus plantarum with prebiotic activity and can be used in functional food ingredients. Full article

Hot cracking in welding is a very complex phenomenon. It can happen in the weld metal zone during solidification but also in the heat-affected zone (HAZ). Hot cracking defects are material decohesion that occur at high temperatures along grain boundaries when the strain and strain rate exceed a certain level. The cracks can be internal or open to the surface in the weld bead. During a welding operation, different types of hot cracks can appear, such as hot cracking due to solidification, hot cracking due to liquation, hot cracking due to loss of ductility. The main factors favoring hot solidification cracking include the presence of residual elements and impurities, leading to the formation of a low-melting eutectic; the solidification mode; and mechanical restraints. This review paper gives an introduction to solidification cracking in stainless-steel welds, the weldability of the austenite grades, and the causes of solidification cracking occurrence. The main methods with which to detect and inspect cracks are investigated. Particular focus is placed on TIG (tungsten inert gas), also known as Gas Tungsten Arc Welding (GTAW). A review of the literature reveals that considerable progress has been made in terms of the improvement in the properties of the weld joint through the application of mitigation means and strategies. The effort made by researchers in understanding solidification cracking phenomena has been key to enhancing cracking resistance and ensuring the integrity of structures. Full article

Developing biodegradable and functional polymeric materials for active food packaging is essential to mitigate the environmental burden of petroleum-based plastics. In this context, gelatin/chitosan (G–Ch) nanofibrous mats were fabricated via solution blow spinning (SBS) and functionalized with snail slime (SS) and Pinus sylvestris essential oil (PSEO) to enhance their bioactivity and barrier performance. SS is rich in glycoproteins and natural bioactive compounds, while PSEO is characterized by terpene-based antimicrobial and antioxidant activities. SS and PSEO were incorporated into the G–Ch polymeric matrix to enhance the bioactivity, structural functionality and preservation performance of the nanofibrous mats. Three formulations (G–Ch, G–Ch–SS, and G–Ch–SS–10PSEO) were designed to elucidate the influence of snail slime and essential oil incorporation on the structure–property–function relationships of the nanofibrous mats. Morphological analysis revealed a smooth and bead-free fibrous structure across all formulations. The average fiber diameter (AFD) increased from 191.83 nm for G–Ch to 263.88 nm for G–Ch–SS and 295.83 nm for G–Ch–SS–10PSEO. FTIR and XRD analyses showed the physical encapsulation of the active compounds without significant chemical interactions. Furthermore, the incorporation of PSEO increased surface hydrophobicity and reduced air permeability, indicating the formation of a more compact fibrous structure with enhanced barrier properties. The functional performance of the nanofibrous mats was significantly improved by the addition of snail slime and PSEO. The G–Ch–SS–10PSEO formulation exhibited the highest antioxidant activity, reaching 36.8% for DPPH and 42.7% for ABTS, along with enhanced antibacterial efficacy against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Application tests on chicken wings demonstrated that the bioactive nanofibers effectively suppressed microbial growth, limited pH increases, and reduced lipid oxidation during 14 days of refrigerated storage. Overall, the results demonstrate that the synergistic integration of snail slime and essential oil within a biodegradable polymer matrix provides a promising strategy for designing active nanofibrous materials with enhanced structural and bioactive properties for sustainable food-packaging applications. Full article

Most adsorbent materials typically face difficulties such as poor blood compatibility, weak mechanical strength, and high cost. In this study, oxidized 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was used to obtain cellulose nanofiber (TOCN), and cellulose beads were prepared using a drop curing method. The structure, adsorption properties, and blood compatibility of the prepared beads were thoroughly investigated. The TOCN beads exhibit a uniform, nanometer-scale, three-dimensional porous structure. With increasing carboxyl content, after adsorption of TOCN beads, the bilirubin concentration in rabbit plasma decreased from 0.03 to 0.0089 mg mL⁻¹ within 90 min, which is significantly lower than the average bilirubin concentration in humans (about 0.01 mg mL⁻¹), and the bilirubin concentration decreased by about 70%. The results illustrated the excellent blood compatibility, self-anticoagulant ability, and superior toxin removal capabilities of the TOCN beads, highlighting their potential as an ideal blood purification adsorbent. Full article

The welded bead bending test (WBBT) serves as a pivotal procedure for evaluating the crack-arrest capacity of structural steels used for construction of safety-critical infrastructure according to ZTV-ING Part 4 or Deutsche Bahn Standard 918 002-02. Previous research has established that light optical microscopy images (LOMs) of specimens that do not pass the WBBT are frequently characterised by a high prevalence of Widmanstätten ferrite within the base material. While convolutional neural networks (CNNs) have successfully classified WBBT outcomes based on LOMs, the implemented approaches did not enable simultaneous pixel-wise delineation required for accurate quantification of Widmanstätten ferrite. However, the tonal similarity between Widmanstätten ferrite and polygonal ferrite renders conventional intensity-based thresholding ineffective for differentiation, necessitating a morphology-based segmentation approach. The present study proposes an automated semantic segmentation framework for the precise delineation of three microstructural phases present within the WBBT LOMs: polygonal ferrite, pearlite, and Widmanstätten ferrite. Utilising a dataset of 20 LOMs and corresponding manually annotated masks, five UNet encoder backbones were evaluated: ResNet-152, Xception, SE-ResNet-50, DenseNet-169, and EfficientNet-B5. To identify the optimal configuration for this microstructural segmentation task, each architecture was assessed using three distinct weight initialisation strategies: (A) ImageNet, (B) MicroNet, and (C) a combined approach. For Widmanstätten ferrite segmentation at patch level, DenseNet-169 pretrained on ImageNet achieves the best performance (Dice: 50.75% ± 3.38%, IoU: 38.45% ± 3.01%). Following inference-based aggregation, Xception pretrained on ImageNet yields improved results (Dice: 68.74% ± 1.12%, IoU: 52.52% ± 1.28%), with an MAE of 4.55% ± 0.80%. Full article

Several sensitive bioactive substances are potent antioxidants that protect the skin from free radicals but are often rapidly degraded, limiting their effectiveness. Encapsulating these substances in liposomes improves their bioavailability and solubility and protects them from harmful environmental factors. The influence of liposomes as advanced lipid nanocarriers is increasing enormously due to their remarkable properties and protection of bioactive substances. For this reason, mango (Mangifera indica L.) peel extract (MPE), previously characterized and rich in various natural substances, including ellagic acid, gallic acid, and catechin, has been encapsulated in liposomes. The investigation focused on the impact of different liposome synthesis process parameters on their size, size distribution, stability, and encapsulation efficiency, and on in vitro release as a potential advanced MPE delivery system with suitable characteristics. An important study on the influence of the organic solvent used in liposome synthesis on the above properties is described. The thin lipid film hydration method using 5-mm glass beads and ethanol as an organic solvent was the most favorable method for synthesizing a stable and monodisperse lipid–MPE delivery system. MPE was successfully encapsulated in liposomes with the highest encapsulation efficiency of 53.7%. The sustained release of MPE from the liposomes was achieved, and the antibacterial properties of MPE, incorporated into the liposomes, were retained. For the first time, MPE has been encapsulated in liposomes, and with the remarkable results obtained, the extract represents a formulation with high added value that can be used in various fields, especially for the enrichment of different products such as cosmetic creams and lotion. Full article

Objective: Intracranial infection is a severe complication that can occur following neurosurgery, and early diagnosis is crucial for improving patient prognosis. In this study, we aimed to investigate, from an exploratory perspective, whether the immune microenvironment of intraoperative cerebrospinal fluid (CSF) is associated with postoperative intracranial infection (PII) in patients undergoing craniotomy for benign brain tumors. Methods: A total of 134 patients undergoing neurosurgery for benign brain tumors were included and categorized into an infection group (n = 18) and a non-infection group (n = 116). CSF samples were collected aseptically immediately after dural opening during surgery. The concentrations of 16 cytokines, including monocyte chemoattractant protein-1 (MCP-1); macrophage inflammatory protein-1α (MIP-1α) and MIP-1β; interleukin (IL)-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, and IL-17; interferon (IFN)-α and IFN-γ; tumor necrosis factor-α (TNF-α); and granulocyte colony-stimulating factor (G-CSF), were quantified using Cytometric Bead Array (CBA) technology. An independent samples t-test was used for normally distributed data, while the Mann–Whitney U test was applied for non-normally distributed data. Group comparisons were performed using independent-samples t-tests or Mann–Whitney U tests for continuous variables and χ² tests or Fisher’s exact tests for categorical variables. The Benjamini–Hochberg false discovery rate (FDR) correction was applied to all 16 cytokines to control for multiple testing. Receiver operating characteristic (ROC) curve analysis was performed to assess discriminatory capacity. Statistical significance was defined as p < 0.05. Results: PII developed in 18 of 134 patients (13.4%). Age (47.78 vs. 54.86, p = 0.028) and operative duration (390 vs. 244 min, p = 0.005) showed differences in unadjusted analyses. In the unadjusted comparisons, MCP-1 and IL-4 levels were found to be significantly lower in the infection group (MCP-1: 57.78 vs. 116.03 pg/mL, p = 0.003; IL-4: 24.38 vs. 28.18 pg/mL, p = 0.032). No cytokine remained significant after FDR correction. The ROC analysis showed that age and IL-4 demonstrated mild discriminatory performance, with AUC values of 0.665 (95% CI 0.526–0.803, p = 0.025) and 0.657 (95% CI 0.540–0.774, p = 0.032), while MCP-1 and operative duration demonstrated modest discriminatory performance, with AUC values of 0.716 (95% CI 0.595–0.838, p = 0.003) and 0.708 (95% CI 0.578–0.838, p = 0.002). Conclusions: In this study, single-point intraoperative CSF cytokines were not significantly associated with PII after stringent correction for multiple testing, and did not provide a validated clinical prediction tool. The unadjusted and direction-corrected findings for MCP-1 and IL-4 remain exploratory and require validation. Full article

Municipal wastewater treatment plants (WWTPs) are designed and operated with nitrogen removal as the primary constraint. Reliance on nitrification–denitrification-based treatment results in significant nitrous oxide (N₂O) emissions. We propose a paradigm shift in WWTP operation, in which nitrogen removal is transformed into an opportunity for resource recovery. Ammonium remaining in the treated effluent is subsequently recovered via ion exchange (IX) and converted into high-purity ammonium salts using a novel, closed-loop, high-pH, low-volume, controlled-regeneration process. Two IX materials are investigated for compliance with the method: zinc hexacyanoferrate composite beads and clinoptilolite-type zeolite. Operating WWTPs using this approach can achieve energy self-sufficiency while contributing to a circular nitrogen economy. Full article

Excess phosphate in aquatic environments can trigger eutrophication and pose risks to ecosystem integrity and public health, even though phosphate is indispensable for plant growth. Herein, we report the fabrication of Zr-LDHs-PS hydrogel microspheres by in situ cross-linking zirconium–magnesium–iron layered double hydroxides (ZrMgFe-LDHs) with Polyvinyl alcohol (PVA) and sodium alginate (SA). The resulting bead-type adsorbent was designed to enable efficient phosphate capture from water while facilitating subsequent, controlled phosphate release. Benefiting from the cross-linking granulation strategy, the microspheres mitigate typical limitations of powdered adsorbents, including compaction, aggregation, and poor separability. General characterization (SEM, FT-IR, XPS, XRD, BET, TG, and zeta potential) elucidated the microstructure and surface chemical composition. The Zr-LDHs-PS microspheres exhibited a maximum experimental adsorption capacity of 51.313 mg/g. Kinetics data were best fitted by the pseudo-second-order model, and adsorption isotherms were subjected to the Freundlich model, pointing to heterogeneous, multilayer adsorption. Importantly, high phosphate selectivity was preserved despite the coexistence of competing anions (Cl⁻, NO₃⁻, and CO₃²⁻). After adsorption, the spent beads released phosphate gradually in water, highlighting their potential for dual functionality. Collectively, these results demonstrate that Zr-LDHs-PS hydrogel microspheres are promising candidates for extraction-based phosphate removal and resource recovery, with prospects for repurposing slow-release phosphate fertilizers to support sustainable plant nutrition. Full article

Microplastics pose a growing threat to marine ecosystems as they can accumulate in aquatic organisms, interfering with essential physiological processes including reproduction. This study analyzed the effects of short-term exposure (48 h) to two concentrations (0.5 and 1 µg/mL) of 5 µm diameter polystyrene microplastic bead particles in female Mytilus galloprovincialis mussels, a bioindicator species of the Mediterranean Sea. Histological analyses revealed progressive oocyte degeneration and the development of hypertrophic PAS-positive mucous cells, indicative of a stress response, in a dose-dependent manner. Changes in hemocyte classes, which are major effectors of bivalve immunity, were evidenced by the May–Grünwald Giemsa reaction. Biochemical data showed that microplastics increased levels of stress proteins, such as HSP70 and p53, and altered the composition of ovarian glycoproteins. Metabolomic analysis based on ¹H NMR spectrometry revealed significant alterations in metabolites involved in energy (glucose, glycogen, and malonate) and amino acid (branched-chain amino acids arginine, glycine, glutamate, histidine, betaine, and choline) metabolism, suggesting impairment to bioenergetic and antioxidant pathways. Overall, these results suggest that even short-term exposure to polystyrene microplastic beads can alter the ovarian function and metabolism of female M. galloprovincialis, highlighting their vulnerability. Full article

A low matrix effects (MEs) analytical strategy was developed for quantifying diazepam (DZP) in aquatic products by combining immunomagnetic bead (IMB)-based sample pretreatment with UPLC-MS/MS. The preparation conditions of IMBs, sample extraction, and purification were systematically optimized. Due to the weak MEs of this method, the quantification of DZP was carried out using a solvent-based calibration curve with an external standard solution. Good linearity was achieved over the range of 0.5–20 ng/mL with a correlation coefficient (R²) of 0.9971. The LOD and LOQ were 0.125 μg/kg and 0.25 μg/kg, respectively. Recoveries ranged from 85.5% to 106%, with intra-day and inter-day precisions of 1.16–7.04% and 3.42–8.99%, respectively. This work has established a robust, rapid, and practical methodology for DZP residue monitoring in aquatic products. Moreover, it serves as a methodological foundation for the detection of other low-molecular-weight contaminants in complex food matrices, thereby enhancing the surveillance and risk assessment for aquaculture products. Full article

Localized optical absorption by nanoscale inclusions can profoundly alter energy deposition in optical traps, giving rise to nonlinear and long-timescale dynamics. Recent experiments have reported the formation of expanding optically darkened regions and episodic plasma-like emission during pulsed near-infrared optical trapping of magnetic beads interacting with biological cells. Here, we develop a reduced-order mechanistic model to investigate whether absorber-driven optical–thermal feedback associated with Fe₃O₄ inclusions is sufficient to reproduce the observed pre-plasma darkening dynamics. The model is constructed progressively from first-principles electromagnetic absorption and pulse-scale thermal diffusion to nonlinear feedback mediated by an evolving optically modified region. Single-pulse and multi-pulse simulations demonstrate that isolated iron-oxide absorbers cool too rapidly to sustain long-timescale thermal accumulation through linear heating alone. However, incorporation of a bubble-mediated optical feedback channel produces bounded growth, partial optical darkening, and slow relaxation dynamics consistent with experimentally observed minute-scale evolution. Electromagnetic absorption was computed using full core–shell Mie theory, yielding absorption cross-sections sufficient to support strong localized optical attenuation under experimentally relevant trapping conditions. The resulting reduced-order feedback framework reproduces stable growth–relaxation cycles, finite transmission plateaus, and self-limited optical darkening without requiring runaway heating or catastrophic cavitation. To evaluate the model quantitatively, simulated transmission dynamics were compared against experimentally measured normalized transmission traces digitized from previously reported optical trapping experiments. The fitted model reproduced the observed finite transmission plateau and slow post-activation relaxation with good agreement ($R^2\approx 0.86$, RMSE $\approx 1.3\times {10}^{-2}$). These results support the interpretation that experimentally observed optical darkening arises from a feedback-regulated optical–thermal process involving slowly evolving structural modification of the trapping region rather than cumulative thermal storage within isolated absorbers. The present framework provides a quantitatively constrained reduced-order description of feedback-mediated optical darkening under pulsed optical trapping conditions and establishes iron-oxide absorption as a physically plausible ignition mechanism for dark-state formation in the pre-plasma regime. Full article