Search Results (313)

Korean rockfish, Sebastes schlegeli, a coastal species, is vulnerable to pollutants such as microplastics and bacteria. While interactions between microplastics and other pollutants have been studied, little is known about microplastic and bacteria interactions. This study examined the effects of combined exposure to polystyrene microplastics in the form of microbeads (MB; 0.2 µm, 5 and 50 beads/L) and Streptococcus iniae (1 × 10⁵ and 1 × 10⁷ CFU/mL) for five days on oxidative stress and apoptosis in Korean rockfish. We assessed the mRNA expression and activity of oxidative stress markers (SOD, CAT, H₂O₂, NO, CYP1A1, GST), plasma LPO levels, and caspase-3 expression in liver tissue. Co-exposure to high MB and S. iniae concentrations significantly elevated oxidative stress and apoptosis markers, suggesting enhanced toxicity. This may result from MB facilitating pathogen transport into the fish, indicating microplastics can act as vectors for bacterial infection in aquatic environments. Full article

Microbeads of raspberry extract were produced using encapsulation matrices alginate + pea protein isolate + psyllium mucilage, alginate + pea protein isolate + psyllium mucilage + okra, and alginate + pea protein isolate + psyllium mucilage + Aloe ferox gel + gallic acid using freeze-drying method. The microbeads were characterised and assessed for their effectiveness on the release, bioaccessibility, of anthocyanin components and antioxidant activities during in vitro digestion. Alginate + pea protein isolate + psyllium mucilage + Aloe ferox gel + gallic acid matrix showed the highest encapsulation efficiency of 91.60% while the lowest encapsulation efficiency was observed in alginate + pea protein isolate + psyllium mucilage + okra (69.94%). Scanning electron microscope images revealed spherical shapes and varying surface morphologies for different encapsulation matrices. Despite the differences observed in Fourier transform infrared spectra, microbeads showed similar thermal degradation patterns. X-ray diffractograms showed amorphous structures for different encapsulation matrices. Comparatively, alginate+ pea protein isolate + psyllium mucilage + Aloe ferox gel + gallic acid microbeads exhibited the highest bioaccessibility for total phenols (93.14%), cyanidin-3-O-sophoroside (54.61%), and cyanidin-3-O-glucoside (55.30%). The encapsulation matrices of different biopolymer combinations (alginate+ pea protein isolate+ psyllium mucilage, alginate + pea protein isolate + psyllium mucilage + okra, and alginate + pea protein isolate + psyllium mucilage + Aloe ferox gel + gallic acid) enhanced anthocyanin stability and protected it against in vitro degradation of bioactive compounds. Full article

Tonsils are secondary lymphoid organs that play a crucial role in the immunological response, with B cells being a major component involved in both innate and adaptive immunity. Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome and obstructive sleep apnea syndrome (OSAS) are both common pediatric conditions involving tonsillar pathology. In both syndromes, the molecular pathways dysregulated in tonsillar B cells are still to be understood. The study aimed to unravel and compare the proteomic profiles of tonsillar CD19+ B cells isolated from pediatric patients with PFAPA (n = 6) and OSAS (n = 6) to identify disease-specific molecular signatures. B cells were isolated from the tonsillar tissue using magnetic microbeads (with a purity of 93.50%). Proteomic analysis was performed by nanoLC-MS/MS with both data-dependent (DDA) and data-independent acquisition (DIA) methods, followed by comprehensive bioinformatic analysis. By merging DDA and DIA datasets, a total of 18.078 unique proteins were identified. Differential expression analysis revealed 83 proteins increased and 49 proteins decreased in OSAS B cells compared to PFAPA B cells (fold change ≥ 1.5 or ≤0.6, p < 0.05). Distinct pathway enrichments were highlighted, including alterations in the regulation of PTEN gene transcription, circadian gene expression, inflammasome pathways (IPAF and AIM2), and the metabolism of angiotensinogen to angiotensin. Specific proteins such as p53, Hdac3, RPTOR, MED1, Caspase-1, Cathepsin D, Chymase, and TLR2 (validated by WB) were shown to be differentially expressed. These findings reveal distinct proteomic signatures in tonsillar B cells from patients with PFAPA and OSAS, offering novel insights into the pathophysiology and potential avenues for biomarker discovery. Full article

Microplastics (MPs) have emerged as a critical environmental challenge in China’s aquatic ecosystems, driven by rapid industrialization and population growth. This review synthesizes recent findings on the abundance, morphology, and polymer types of MPs in China’s freshwater systems (rivers, lakes, reservoirs) and coastal marine environments. Spatial analysis reveals significant variability in MP abundance, ranging from 0.1 items/L in Tibet’s Lalu Wetland to 30.8 items/L in Beijing’s Qinghe River, with polypropylene (PP) and polyethylene (PE) dominating polymer profiles. Coastal regions exhibit distinct contamination patterns, with the Yellow Sea (5.3 ± 2.0 items/L) and the South China Sea (180 ± 80 items/m³) showing the highest MP loads, primarily as fibers and fragments. Fluvial transport, atmospheric deposition, and coastal anthropogenic activities (e.g., fisheries, tourism) are identified as major pathways for marine MP influx. Secondary MPs from degraded plastics and primary MPs from industrial/domestic effluents pose synergistic risks through the adsorption of heavy metals and organic pollutants. Human exposure routes—ingestion, inhalation, and dermal contact—are linked to inflammatory, metabolic, and carcinogenic health outcomes. Policy interventions, including bans on microbeads and non-degradable plastics, demonstrate progress in pollution mitigation. This work underscores the urgency of integrated source control, advanced wastewater treatment, and transboundary monitoring to address MP contamination in aquatic ecosystems. Full article

In order to clarify the feasibility of constructing a gas storage reservoir through synergistic injection and production in the target reservoir, micro-displacement experiments and multi-cycle injection–production experiments were conducted. These experiments investigated the displacement characteristics and the factors affecting storage capacity during the multi-cycle injection–production process for converting the target reservoir into a gas storage facility. Microscopic displacement experiments have shown that the remaining oil is primarily distributed in the dead pores and tiny pores of the core in the form of micro-bead chains and films. The oil displacement efficiency of water flooding followed by gas flooding is 18.61% higher than that of gas flooding alone, indicating that the transition from water flooding to gas flooding can further reduce the liquid saturation and increase the storage capacity space by 2.17%. Single-tube long-core displacement experiments indicate that, during the collaborative construction of a gas storage facility, the overall oil displacement efficiency without a depletion process is approximately 24% higher than that with a depletion process. This suggests that depletion production is detrimental to enhancing oil recovery and expanding the capacity of the gas storage facility. During the cyclic injection–production stage, the crude oil recovery rate increases by 1% to 4%. As the number of cycles increases, the incremental oil displacement efficiency in each stage gradually decreases, and so does the increase in cumulative oil displacement efficiency. Better capacity expansion effects are achieved when gas is produced simultaneously from both ends. Parallel double-tube long-core displacement experiments demonstrate that, when the permeability is the same, the oil displacement efficiencies during the gas flooding stage and the cyclic injection–production stage are essentially identical. When there is a permeability contrast, the oil displacement efficiency of the high-permeability core is 9.56% higher than that of the low-permeability core. The ratio of the oil displacement efficiency between the high-permeability end and the low-permeability end is positively correlated with the permeability contrast; the greater the permeability contrast, the larger the ratio. The research findings can provide a reference for enhancing oil recovery and expanding the capacity of the target reservoir when it is converted into a gas storage facility. Full article

Circulating tumor cell enrichment and enumeration are advancing early detection of cancer, monitoring of therapy response, and even next-generation therapies. Efficiently capturing rare cells from complex biological fluids is essential in both diagnostic and therapeutic applications. EpCAM-positive tumor cells are specifically captured by utilizing covalently immobilized anti-EpCAM monoclonal antibodies onto the surface of chemically modified glass microbeads. To maximize the capture efficiency, bead geometry, immobilization conditions, flow rate, and anticoagulant dosage were systematically optimized. An in vitro flow-capture system was designed and used to evaluate the capture efficiency of the proposed technology by utilizing HTC116 colon cancer cell-spiked model media. The effect of substrate surface pretreatment was characterized by goniometry, while the capture performance was monitored by flow cytometry and fluorescent microscopy. The specific capture ability of the bioactive microbead substrate reached over 130,000 cells in the laboratory-scale cartridge (V(cartridge) = 2.6 cm³; m(bead) = 4 g). This capture efficiency suggests a promising rare-cell capture utilization of the proposed technology and may be used for research, diagnostic, and therapeutic purposes. In this paper, we reported on the development and feasibility test of a high-performance bioactive glass-microbead cell capture substrate. Due to the relevance and novelty of the reported results, with further development, the versatile platform technology presented could be readily implemented to capture tumor cells from complex biological samples and represent an additional complementary tool to existing cancer diagnostics and therapies. Full article

Negative temperature environments inhibit bacterial survival in cementitious materials and reduce the self-healing ability of bacteria. To address this challenge, acid-etched alumina hollow spheres are proposed as carriers to encapsulate microorganisms in cementitious materials. The effects of these carriers on the mechanical properties, thermal conductivity, self-healing properties, and self-healing products of specimens after exposure to −20 °C were investigated. Finally, the self-healing mechanism was examined and analyzed. The results demonstrated the effectiveness of the acid-etched hollow microbeads as bacterial carriers. The addition of the alumina hollow spheres participating in the cement hydration reaction enhanced the mechanical properties of the mortar and reduced its thermal conductivity, which supported bacterial survival in the negative temperature environment. Although negative temperature environments may reduce bacterial populations, the hydrolysis of aluminum ions in the alumina hollow spheres during bacterial metabolism resulted in the precipitation of aluminum hydroxide flocs. These flocs adsorbed free calcium carbonate in the pores, converting it into effective calcium carbonate with cementing properties, thus enhancing the crack healing capability of the examined specimens. This microbe-based self-healing strategy, utilizing alumina hollow spheres as bacterial carriers, is anticipated to provide an effective solution for achieving efficient crack self-healing in mortars that is resistant to the detrimental effects of negative temperature conditions. Full article

(1) Background: Glaucoma is a multifactorial group of diseases characterized by progressive optic neuropathy. Intraocular pressure (IOP) is the only successfully modifiable risk factor for all forms of glaucoma. However, recent research has highlighted the reduction of oxidative stress and neuroinflammation as promising therapeutic targets. In this study, we evaluated the antiglaucomatous effects of a combined herbal extract applied as eye drops in a rat model of glaucoma. (2) Methods: Sprague Dawley rats were divided into four groups: healthy controls, glaucomatous animals treated with preservative-free artificial tears, and healthy and glaucomatous groups receiving combined herbal-based eye drops for 8 weeks. Glaucoma was induced through injection of microbeads into the anterior chamber at week 1 and week 3. Before the first injection and at weeks 4 and 8, rats underwent optical coherence tomography (OCT) and electroretinogram (ERG) recordings. Retinal analyses were conducted to assess retinal ganglion cell (RGC) count, vessel density, and markers of neural pathways, oxidative stress, and inflammation. (3) Results: The combination of herbal extracts showed beneficial effects on IOP elevation, and significantly improved ERG responses. Neuroprotective effects were assessed using OCT, immunohistochemistry, and proteomics. Most parameters in herbal eye drop-treated rats were not statistically different from those in healthy controls. (4) Conclusions: Topical administration of plant-based compounds may serve as an effective supportive therapy for ocular hypertension and retinal neuroprotection. Full article

Many countries have established regulatory frameworks to monitor and mitigate Salmonella contamination in poultry products. The ability to rapidly quantify Salmonella is critical for poultry processors to facilitate early detection, implement corrective measures, and enhance product safety. This study aimed to develop an Immunomagnetic Chemiluminescent Assay (IMCA) for the quantification of Salmonella Typhimurium in ground chicken. Immunomagnetic microbeads functionalized with monoclonal antibodies were employed to selectively capture and concentrate Salmonella from ground chicken samples. A biotin-labeled monoclonal antibody, followed by an avidin-horseradish peroxidase conjugate, was used to bind the captured bacteria and initiate a chemiluminescent reaction catalyzed by peroxidase. Light emission was quantified in relative light units (RLUs) using two luminometers. Ground chicken samples were inoculated with a four-strain S. Typhimurium cocktail ranging from 0 to 3.5 Log CFU/g. Bacterial concentrations were confirmed using the Most Probable Number (MPN) method. Samples underwent enrichment in Buffered Peptone Water (BPW) supplemented with BAX MP Supplement at 42 °C for 6 and 8 h before analysis via IMCA. A linear regression analysis demonstrated that the optimal quantification of Salmonella was achieved at the 8 h enrichment period (R² ≥ 0.89), as compared to the 6 h enrichment. The limit of quantification (LOQ) was determined to be below 1 CFU/g. A strong positive correlation (R² ≥ 0.88) was observed between IMCA and MPN results, indicating methodological consistency. These findings support the application of IMCA as a rapid and reliable method for the detection and quantification of Salmonella in ground chicken. Full article

Gold nanoparticles (AuNPs) have surface plasmon resonance (SPR) and catalytic activity that are not found in bulk gold and have been studied in various fields. Among these, immobilization of AuNPs on various solid-phase substrates is known to produce stable catalytic activity and specific SPRs and research on the immobilization of AuNPs has been conducted actively. However, the conventional method requires the preparation and immobilization of AuNPs in separate processes, making it difficult to prepare immobilized AuNPs in a one-pot process. In this study, we attempted to synthesize and immobilize AuNPs using peptidyl beads, which are microbeads having immobilized a peptide capable of reducing gold ions. We successfully reduced Au ions from 0.5 to 1000 µM of HAuCl₄ and immobilized them on peptidyl beads in the form of AuNPs. The immobilized AuNPs have a constant particle size independent of the HAuCl₄ concentration. Furthermore, the peptidyl beads with AuNPs have catalytic activity. The quantity of the AuNPs on the peptidyl beads and, subsequently, the catalytic reaction rate of the sample, could be controlled. This study would also be expected to be applied to the immobilization of metallic nanomaterials other than AuNPs by modifying the peptide sequence. Full article

Analyzing metabolite levels in bodily fluids is essential for disease diagnosis and surveillance. Electrochemical biosensors are ideal for monitoring metabolite levels due to their high sensitivity, rapid response, and low cost. The magnetic microbeads-based electrode functionalization method further promotes the automation development of electrochemical biosensors by eliminating the tedious electrode polishing process. In this study, we presented sea urchin-like magnetic microbeads (SMMBs) and constructed an SMMB-based electrochemical biosensor. The specific morphology of SMMBs provides a larger specific surface area and abundant enzyme binding sites, thereby expanding the active reaction interface on the electrode and improving the sensitivity of the biosensor. Experiment results demonstrated that the SMMB-based electrochemical biosensor achieves μM level detection sensitivity for glucose. Furthermore, by replacing the anchored oxidase on SMMBs, the biosensor can be extended to detect other metabolites, such as cholesterol. In summary, the SMMBs provide a new path to handily construct electrochemical biosensors and hold a great potential for metabolite detection and further development. Full article

This study explores the potential of Vigna mungo gum as a sustainable and innovative natural polymer for developing microbeads for the controlled delivery of vildagliptin, a widely used antidiabetic agent. Unlike conventional natural polymers, Vigna mungo gum offers unique biocompatibility, biodegradability, and an eco-friendly production process, distinguishing it as a superior candidate for drug delivery systems. Microbeads were prepared by combining Vigna mungo gum with sodium alginate and inducing gelation using calcium carbonate. Scanning electron microscopy (SEM) revealed a rough, porous microbead surface, advantageous for drug encapsulation and controlled release. Drug release studies demonstrated sustained release kinetics, highlighting the effectiveness of this formulation. These findings underscore the novelty of Vigna mungo gum as a promising platform for antidiabetic drug delivery, providing a sustainable alternative to existing polymer systems. Full article

Microplastic (MP) contamination in aquafeed poses a significant risk to fish health and safety. This study evaluated the effectiveness of a microencapsulated natural antioxidant, astaxanthin (AX), in mitigating the adverse effects of dietary MPs in rainbow trout fry. The microcapsules were composed of an organic wall matrix designed to preserve AX while limiting MP absorption in the intestine. During a 60-day feeding trial, fish were fed diets containing amino formaldehyde polymer fluorescent MP microbeads (1–5 µm; 50 mg/kg), either alone or in combination with microencapsulated AX. MP localization in tissues was assessed via confocal microscopy, and quantification was performed following chemical tissue digestion. Fish welfare was evaluated using histological and molecular analyses. No significant effects on growth or gut morphology were observed across experimental groups. However, MPs were mainly translocated to the liver, where they induced oxidative stress, as evidenced by the upregulation of sod1, sod2, and cat gene expression. The inclusion of microencapsulated AX significantly mitigated the oxidative stress response, and the microcapsules facilitated MP coagulation in the gut, reducing intestinal absorption. These findings highlight the potential of microencapsulated antioxidants to counteract MP-induced oxidative stress and reduce MP bioavailability in aquaculture species, contributing to improved fish welfare and product quality. Full article

An epoxy/glass microbeads-based 1-3 piezoelectric composite is proposed, to enhance electromechanical conversion efficiency. Firstly, based on the series-parallel theory, the theoretical model is established. Secondly, the epoxy resin/glass microbeads-based 1-3 piezoelectric composite is simulated by finite element software. The effects of polymers with different acoustic impedances, the thicknesses of piezoelectric composites, and ceramic volume fractions are analyzed systematically. After parameter optimization, the epoxy/glass microbeads-based 1-3 piezoelectric composite is prepared. The experimental results agree well with the theoretical and simulation results. When the ceramic volume fraction is 60.0%, its electromechanical coupling factor is the largest, which is 0.714. Compared with the prepared traditional 1-3 piezoelectric composites with the same parameters, its electromechanical coupling factor is increased by 7.8%. Therefore, the epoxy/glass microbeads-based 1-3 piezoelectric composite can enhance the sensitivity and resolution of the transducers, which has potential advantages for improving the performance of transducers. Full article

Extracellular vesicles (EVs) and their cargo are increasingly suggested as innovative biomarkers correlated to the diagnosis, progression and therapy of diseases like cancer. Several techniques have been developed for the specific separation of the different classes of EVs that give solutions enriched in vesicles, but still containing other unwanted components. New methods for a more efficient, reliable and automated isolation of EVs are therefore highly desirable. Here, microparticles with surfaces endowed with positive ions were exploited to separate vesicles from complex biological matrices. First, flat silicon oxide surfaces functionalized with different divalent cations were tested for their efficiency in terms of small EV capture. Small EVs pre-purified via serial ultracentrifugations were employed for these analyses. The two better-performing cations, i.e., Cu²⁺ and Ni²⁺, were then selected to functionalize magnetic microbeads to be inserted in microfluidic chips and evaluated for their efficiency in capturing EVs and for their release of biomarkers. The best protocol setup was explored for the capture of EVs from cell culture supernatants and for the analysis of a class of biomarkers, i.e., microRNAs, via RT-PCR. The promising results obtained with this on-chip protocol evidenced the potential automation, miaturization, ease-of-use and the effective speed of the method, allowing a step forward toward its integration in simple and fast biosensors capable of analyzing the desired biomarkers present in EVs, helping the spread of biomarker analysis in both clinical settings and in research. Full article