Search Results (3,190)

Freshwater scarcity is a major global issue faced by various regions, and the most common portable water sources globally are estuaries, canals, dams, lakes, and rivers. Existing water resources function as the best sinks for the frequent release of effluents from industrial and residential activities. This common practice often results in water pollution, a deterioration in marine biodiversity, and possible health risks for human populations. This study employed standard analytical methods in assessing the physicochemical and microbial characteristics of water samples collected from the Sundays River estuary in Eastern Cape Province (ECP), South Africa (SA). Microbiological assessment revealed that during the spring season, presumptive Escherichia coli (E. coli) colony counts were 1 cfu/100 mL, while total coliforms (TCs) and fecal coliforms (FCs) were recorded at 42.67 cfu/100 mL and 1 cfu/100 mL, respectively. In the summer season, fecal coliform (FC) counts reached 3.5 cfu/100 mL, while Enterococcus levels were higher, ranging up to 77.75 cfu/100 mL. Furthermore, the average standards of physicochemical parameters assessed in water obtained from both spring and summer seasons ranged as follows: pH (8.71–9.31), temperature (20.98–22.21 °C), turbidity (10–35.55 FNU), total alkalinity (22.25–94.00 mg/L), oxidation–reduction potential (ORP) (8.05–151.6 mV), electrical conductivity (EC) (13,915–40,260 uS/cm), salinity (8.07–25.78 psu), dissolved oxygen (DO) (6.79–7.39 mg/L), total dissolved solids (TDSs) (6960.6–20,125 mg/L), and biochemical oxygen demand (BOD) (0.11–2.94 mg/L). The levels of TDS, EC, turbidity, and salinity in the Sundays River estuary water exceeded the World Health Organization (WHO) guidelines of 2017, rendering the water unfit for even recreational purposes. Additionally, the bacterial levels identified in this study were above the values set by the South Africa Department of Water Affairs (SA-DWAF). The identified microorganisms are perceived as essential indicators of fecal contamination and have the potential to multiply in the environment. Possible pollution may be a result of various municipal effluents consistently discharged into the waterbody. Full article

Metabolic diseases are strongly associated with chronic systemic inflammation and oxidative stress, which disrupt the microbiota–gut–brain (MGB) axis and promote neuroinflammation. Dysbiosis favors the release of proinflammatory metabolites, reactive oxygen species (ROS), and lipopolysaccharides (LPS), increasing intestinal permeability and triggering systemic immune responses that reach the central nervous system (CNS) through a weakened blood–brain barrier (BBB). This review summarizes current knowledge on the pathophysiological mechanisms linking the MGB axis, metabolic disorders, and neuroinflammation, as well as the therapeutic potential of antioxidants. A literature search was conducted in PubMed, Web of Science, Scopus, and ScienceDirect and included original research articles, reviews, clinical trials, and meta-analyses related to microbiota, neuroinflammation, oxidative stress, and antioxidant interventions. Evidence indicates that dysbiosis exacerbates metabolic dysfunction by activating the nuclear factor kappa B (NF-κB) and NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome pathways, while excessive ROS production impairs mitochondrial function, neuronal survival, and cognitive processes. Antioxidant strategies, including polyphenols, omega-3 fatty acids, curcumin, vitamins C and E, and probiotics, can restore microbial diversity, reinforce intestinal and BBB integrity, and modulate oxidative and inflammatory signaling. In conclusion, supplements and bacteria with antioxidant properties show promising therapeutic effects by targeting oxidative stress mechanisms involved in metabolic diseases and their pathological consequences, such as dysbiosis and neuroinflammation. Full article

Lignocellulose represents an abundant repository of renewable carbon. Derived from various plant sources, it holds tremendous potential as a renewable and sustainable feedstock for the production of valuable chemicals and fuels. However, its solid fermentable compounds, cellulose and hemicellulose, are embedded within complex lignin structures and are therefore poorly accessible to microbial conversion. This paper describes an artificial rumen reactor (ARR) that uses anaerobic microbes from the cattle rumen to increase the release of fermentable carbon from recalcitrant biomass. We outline the development of an ARR for the efficient conversion of lignocellulosic grass into volatile fatty acids (VFAs), which are valuable precursors for the production of a range of bioproducts, including biofuels, biomaterials, and biochemicals. The ARR, a 4-L bioreactor equipped with a ceramic filtration unit, has been optimised and was operated for extended periods of continuous VFA production. Across distinct short- and long-term observation periods, and independent of the cow from which the rumen microbes originated, the bioreactor demonstrated the ability to sustain VFA production, indicating robustness and stability. At an input of 60–80 g dry grass d⁻¹, the system produced approximately 6 mol VFA per kg of dry matter input (DMI). The decoupling of the Solid Retention Time (SRT; 10 days) and the Liquid Retention Time (LRT; 0.5 days) prevented inhibition of the VFA production. The VFA profile was dominated by acetic and propionic acids, comprising 68% and 19%, respectively, with butyric acid and minor VFAs accounting for the remainder. The application of low oxygen levels (<10%) in the reactor via limited aeration did not affect the VFA yield or its profile. Full article

Cigarette smoke (CS) is the primary risk factor for the development of chronic obstructive pulmonary disease (COPD). Investigating the impact of CS on human airway epithelium is important for understanding COPD development and combating its effects. While some studies show that long exposure to CS activates inflammasome formation in airway epithelium, leading to cytokines’ maturation and release, its acute effect on inflammation regulation requires further elucidation. Due to the importance of acute cellular responses in modulating cell survival and controlling inflammatory outcomes, we examined the effect of acute cigarette smoke extract exposure on human bronchial epithelial cells. Due to the high reactive oxygen species content in CS, we hypothesize that acute CS exposure activates the integrated stress response (ISR) pathway leading to stress granules (SG) formation to facilitate oxidative stress resolution and promote cell survival. Immunostaining, fluorescence confocal imaging, quantitative analyses, and immunoblotting were performed to test our hypothesis. We report here that acute exposure to CS extract triggers canonical SG formation by activating the ISR pathway via the PERK/eIF2α arm in a reactive oxygen species-dependent manner. SG formation is abolished upon inhibiting PERK or eIF2α function, or by scavenging oxidants prior to smoke exposure. Characterizing SG formation in terms of measuring SG size and abundance and the sequestration of the SG marker G3BP1 reveals that SG formation is maximal at 15% CS extract exposure for 2 h and undergoes gradual disassembly at longer exposure times. This is closely dependent on cytoplasmic p-eIF2α levels. These results demonstrate that acute exposure to CS activates the protective ISR pathway to potentially reduce the detrimental effects of CS and promote stress resolution and cell survival. Full article

Excessive neutrophil extracellular trap (NET) formation (NETosis), frequently associated with reactive oxygen species (ROS), exacerbates cutaneous inflammation induced by acute ultraviolet B (UVB) exposure. Although hispidin has potent antioxidant activity, its protective effects against acute UVB-induced skin inflammation and its relationship with NET-associated responses remain unclear. We investigated the effects of topical hispidin on acute UVB-induced skin injury in mice and examined its effects on ROS-associated NET-related responses in differentiated HL-60 cells. In a mouse model, topical hispidin (0.1% and 0.5%) ameliorated UVB-induced skin damage in a dose-dependent manner, as evidenced by improved clinical and histological findings. Hispidin treatment was associated with reduced systemic oxidative stress and decreased cutaneous expression of CXCL2, C5a, IL-1β, NLRP3, Ly6G, PAD4, and citrullinated histone H3. In differentiated HL-60 cells, hispidin reduced ROS-associated signals and suppressed PMA-triggered extracellular DNA release, but did not suppress A23187-triggered extracellular DNA release under experimental conditions. Cell viability analysis showed that hispidin did not significantly affect differentiated HL-60 cell viability at tested concentrations under the present experimental conditions. Topical hispidin alleviates acute UVB-induced skin inflammation by suppressing neutrophil infiltration and NET-related inflammatory responses. Hispidin may therefore represent a promising candidate as a topical modulator of oxidative stress- and NET-associated skin inflammation. Full article

Nitric oxide (NO) is a gaseous biocompatible radical molecule with demonstrated biomedical and antimicrobial benefits. Developing adaptable, long-lasting delivery systems for NO has become an essential goal for both combating resistant bacterial growth and providing sustained medical benefits. Silsesquioxane (SQ)-based organogels were chosen and synthesized as robust, tunable NO-release platforms. These highly stable SQ gel frameworks, composed of silicon–oxygen backbones with variable R groups, exhibited high porosity and surface area and offered chemical versatility, enabling control over NO loading and release. 3-Mercaptopropyl groups were utilized as sulfur-based NO-releasing substituents (-RSNOs), with additional R groups capable of altering accessibility to RSNO sites through hydrophobicity and steric hindrance. The NO release profile, rate, and duration of the functionalized gels were also tailored by adjusting the number of RSNO sites in the elastomeric system, thereby enabling a customizable release profile. This combination of NO-releasing silsesquioxanes with silicone elastomers yields composite materials that are integratable into biomedical applications, offering NO release up to 40 days within modeled physiological conditions in PBS buffer. Full article

This study focuses on the production and characterization of polyvinyl alcohol (PVA)-chitosan (CS)-based nanoparticles loaded with vitamin E (VitE) and ephedrine (Ep) via electrospraying for intranasal drug delivery in narcolepsy treatment. The nanoparticles were successfully synthesized using optimized parameters (15.5 kV voltage, 0.3 mL/h flow rate, 25 G needle size, and 14 cm distance). Scanning electron microscopy (SEM) analysis confirmed the formation of spherical particles with an average size of 350–500 nm, while energy-dispersive X-ray spectroscopy (EDS) mapping revealed a homogeneous elemental distribution with oxygen (51.74%), silicon (24.48%), carbon (6.47%), zinc (6.08%), and aluminum (3.82%). Fourier-transform infrared (FTIR) spectra demonstrated the successful encapsulation of VitE and Ep through characteristic peaks at 3285 cm⁻¹ (OH stretching), 1731 cm⁻¹ (C=O stretching), and 1086 cm⁻¹ (C-O-C stretching). In vitro drug release analysis indicated a controlled and sustained release profile, with cumulative VitE and Ep release reaching 78.6% and 84.3%, respectively, over 48 h in phosphate-buffered saline (PBS, pH 7.4). Antioxidant activity assessment using the DPPH assay confirmed an R² value of 18.84 µg/mL, demonstrating significant free radical scavenging potential. The antibacterial activity, tested via the disk diffusion method, exhibited inhibition zones of 18.31 ± 5.8 mm (E. coli) and 21.51 ± 1.57 mm (S. aureus), confirming strong antimicrobial properties. These findings suggest that the developed electrosprayed PVA/CS nanoparticles loaded with VitE and Ep offer a promising intranasal delivery system with enhanced bioavailability, controlled release, antioxidant capacity, and antibacterial properties, making them a viable candidate for narcolepsy treatment. Full article

Oxidative stress occurs when there is an excess of reactive oxygen species (ROS) in the cell, primarily produced by mitochondria. Excess ROS trigger membrane lipid peroxidation (LPO), cause mitochondrial swelling, and release proapoptotic proteins into the cytoplasm, which can lead to apoptosis. It is assumed that antioxidants that reduce excessive ROS formation by mitochondria can increase the body’s resistance to stress factors. We investigated the effects of hypoxia and the antioxidant Ambiol (2-methyl-4-dimethylaminomethylbenzimidazole-5-ol dihydrochloride) on the functional characteristics of mitochondria, which were assessed by measuring lipid peroxidation intensity using spectrofluorimetry, mitochondrial membranes fatty acid composition using chromatography, mitochondrial morphology using atomic force microscopy, and respiration rate using polarography. Injecting mice with Ambiol at a dose of 10⁻⁶ mol/kg for 5 days prevented the stress-induced activation of lipid peroxidation, a decrease in the unsaturation index of C₁₈ and C₂₀ fatty acids in mitochondrial membranes, and swelling of these organelles. The drug also increased the efficiency of oxidative phosphorylation during the oxidation of NAD-dependent substrates. Furthermore, Ambiol increased the lifespan of mice by 3.0–4.0 times under various types of hypoxia. Ambiol’s ability to maintain initial (control) levels of C₁₈ and C₂₀ unsaturated fatty acids appears to protect against stress-induced mitochondrial dysfunction. Full article

Microplastics (MPs) in wastewater treatment plants are predominantly retained in sewage sludge, making sludge processing a critical stage for MP transformation and potential pollutant release. However, the aging of polyethylene (PE) MPs and the release of MP-derived dissolved organic matter (MP-DOM) during sludge dewatering remain poorly understood. In this study, representative sludge conditioners were set up in dewatering experiments to investigate the changes in PE MP surface properties, pollutant-carrying potential, and MP-DOM release behavior. The results showed that sludge dewatering induced pronounced surface aging of PE MPs, including wrinkling, cracking, particle fragmentation, and the formation of polar oxygen-containing functional groups. These changes significantly increased the Cd adsorption potential of PE MPs, reaching 8228 ± 568 mg kg⁻¹. Lime conditioning promoted stronger fragmentation and a greater reduction in particle size than other conditionings, which likely increased the specific surface area. Meanwhile, a substantial release of PE MP-DOM was observed, with dissolved organic carbon concentrations in sludge process water being 2–30 times higher than those in deionized water. Fluorescence and molecular analyses showed that PE MP-DOM was dominated by protein-like and fulvic-like substances and also contained phthalates, fatty acids, and acetamide-based plasticizers. The magnitude and composition of PE MP-DOM release were strongly regulated by conditioner-induced pH and ionic strength. Alkaline conditions and increasing concentrations of Ca²⁺ (0.1–2.1 mol L⁻¹) and Fe³⁺ (0.006–0.6 mol L⁻¹) enhanced PE MP additive release. These findings demonstrate that sludge dewatering is an active process that accelerates PE MP aging and associated organic release. This work provides new insight into the environmental behavior of MPs during sludge treatment and offers a basis for developing sustainable sludge management. Full article

This study investigates how the initial oxygen fraction in a confined space affects post-vent combustion, gas composition, and pressure hazards during thermal runaway (TR) of 58 Ah prismatic Li(Ni_0.8Co_0.1Mn_0.1)O₂ lithium-ion cells. Thermal abuse experiments were conducted in a 250 L sealed chamber under five initial oxygen fractions (20%, 15%, 10%, 5%, and 0% O₂), with synchronized measurements of cell temperature, vent-jet temperature, chamber pressure, voltage, and post-event gas composition. A first-vent event occurred reproducibly at a cell surface temperature of approximately 155 °C, followed by TR onset at about 170 °C. Although the onset temperatures were only weakly affected by ambient oxygen concentration, the post-vent hazard escalation depended strongly on oxygen availability. As the initial oxygen fraction increased from 0% to 20%, the peak vent-jet temperature increased from 353 °C to 1172 °C, and the peak chamber pressure rose from 90.7 kPa to 523.1 kPa. Gas chromatography showed that H₂, CO₂, CO, CH₄, and C₂H₄ were the dominant gaseous products. Lower oxygen fractions promoted retention of combustible species, whereas higher oxygen fractions enhanced oxidation and increased the CO₂/CO ratio. An oxygen-participation parameter, η, was introduced to quantify the fraction of initially available chamber oxygen consumed during post-vent oxidation. The increase in η was positively associated with oxygen-involved heat release and chamber overpressure. When the accessible oxygen fraction was limited to 10% or below, secondary combustion and pressure buildup were markedly suppressed, although a localized near-field thermal hazard remained significant around 10% O₂. These results provide quantitative guidance for enclosure inerting, vent management, and post-vent hazard mitigation in high-energy lithium-ion battery systems. Full article

Background/Objectives: Biodegradable magnesium (Mg)-based biomaterials release Mg²⁺ ions during degradation and may promote vascular-related regeneration. However, their effects on lymphatic endothelial cells (LECs) and lymphangiogenesis remain unclear. This study investigated whether magnesium powder-derived ionic extracts could enhance lymphangiogenesis-related behaviors of LECs in vitro. Methods: Mg powder extracts were prepared and diluted for in vitro treatment. After viability screening, Mg (1:10), Mg (1:100), and Mg (1:1000) were selected for further analysis. LEC proliferation, migration, and tube formation were assessed, together with intracellular reactive oxygen species (ROS) levels and the expression of VEGFA, VEGFC, and VEGFR3. Results: Mg (1:10) and Mg (1:100) showed good cytocompatibility and significantly promoted LEC proliferation, migration, and tube formation compared with the control and Mg (1:1000) groups. These effects were accompanied by reduced intracellular ROS levels and increased expression of VEGFA, VEGFC, and VEGFR3. Conclusions: Magnesium powder-derived ionic extracts enhance lymphangiogenesis-related responses of LECs in vitro, particularly at the 1:10 and 1:100 dilutions. These findings support the potential of Mg-based biodegradable biomaterials for lymphatic tissue regeneration. Full article

Phosphorus release from sediments significantly influences eutrophication in shallow lakes; however, its dynamics in drawdown zones under alternating inundation and drying cycles remain understudied. This study investigates the mechanisms of phosphorus release from sediments in the drawdown zone of Nansi Lake, a key reservoir along the eastern route of the South-to-North Water Diversion Project. Through field sampling and laboratory simulations, we analyzed the impact of inundation duration, physicochemical properties, and organic matter decomposition on phosphorus release. In Container a (first inundation period), phosphorus was rapidly released at the beginning of inundation, with total phosphorus (TP) in the overlying water increasing from 1.92 mg/L to 2.68 mg/L, and in the interstitial water from 8.45 mg/L to 15.24 mg/L. The second inundation period showed the highest phosphorus release, with TP reaching 3.61 mg/L in the overlying water and 21.51 mg/L in the interstitial water. Inorganic phosphorus dominated the release, with dissolved inorganic phosphorus (DIP) accounting for a higher proportion of TP than dissolved organic phosphorus (DOP). Changes in pH, oxidation-reduction potential (ORP), dissolved oxygen (DO), and total organic carbon (TOC) significantly influenced phosphorus distribution. The decomposition of organic matter during inundation increased dissolved organic matter levels, thereby affecting phosphorus release. These findings provide valuable insights into phosphorus dynamics and highlight the need for integrated management strategies to mitigate internal phosphorus loading and prevent eutrophication in Nansi Lake, offering guidance for water quality management and ecological protection in similar shallow lake systems. Full article

Phenolic compounds contribute to the color, flavor, and functionality of foods but are often degraded during conventional heat treatments, prompting interest in non-thermal techniques. Thermal methods produce heat-driven changes that are more directly interpretable, whereas non-thermal methods require compound-resolved interpretation because higher post-treatment signals may reflect release from bound pools rather than true preservation. This review evaluates liquid chromatography–mass spectrometry (LC–MS) evidence on how ultrasound, high-pressure processing, pulsed electric fields, and cold plasma reshape polyphenol fingerprints across food matrices (2021–early 2026). Ultrasound and high-pressure processing preserve constitutive structures while increasing measurable phenolics through cell disruption and bound-pool release. Pulsed electric fields show similar release behavior but may shift toward oxidative losses when electroporation increases enzyme contact or downstream operations amplify degradation. Cold plasma introduces reactive oxygen and nitrogen species, with the clearest LC–MS/MS evidence for oxidation and nitration. In fresh-cut tissues, stress responses elevate phenylpropanoid products. Bulk assays such as total phenolic content (TPC) cannot separate preservation from release or true chemical conversion alone. LC–MS offers the compound-level detail needed to understand how each non-thermal technique changes polyphenol structure and functionality across food matrices. Full article

Obesity is a chronic disease characterized by excessive fat accumulation. Irisin, released during exercise, regulates energy metabolism and may contribute to exercise-induced metabolic adaptations. This study aimed to compare the effects of 24 weeks of two different training programs on body composition, physical capacities, and irisin levels in male adults with obesity, and to investigate the relationship between irisin and metabolic parameters. Thirteen male adults with obesity were randomly assigned to polarized (POL) or threshold (THR) training programs. Anthropometric measurements, physical capacity parameters, serum and salivary samples were collected before (T0) and after the training period (T1). Irisin levels were measured by ELISA. After training, body composition significantly improved, with reductions in body mass and body mass index, and an increase in fat-free mass. Maximal oxygen consumption (V’O₂max) significantly increased, while a decrease in HRmax indicated improved cardiac efficiency. Although serum and salivary irisin levels did not significantly increase overall, a trend toward increased irisin was observed in the THR group. Furthermore, serum irisin at T1 positively correlated with V’O₂ at the respiratory compensation point (p = 0.019), and V’O₂max (p = 0.031). Both POL and THR training programs significantly improved body composition and cardiometabolic fitness after 24 weeks. The positive association of irisin with aerobic fitness parameters suggests that irisin may reflect physiological adaptations to exercise. Full article

The lung–kidney axis forms an important physiologically integrated system which controls multiple essential functions of the body. An important observation of this interaction is tissue oxygenation and erythropoiesis, a vital process that involves erythropoietin (EPO) release by the kidney to bring red cell production into the bone, while pulmonary gas exchange ensures adequate oxygen delivery to the cells. Subsequently, the lung–kidney activation of the renin angiotensin system (RAS) influences vascular tone, blood pressure, and tissue perfusion, influencing the delivery of oxygen and the body’s requirement for erythropoietin. Additionally, beyond oxygen sensing, studies have evidenced the role of hypoxia-inducible factors (HIFs), inflammatory mediators, endothelial signaling pathways and iron availability. These modulate erythropoietin production, which enhances the process of erythropoiesis and arterial oxygen balance. Localized variations in renal oxygen levels together with hemodynamic control mechanisms enable the body to produce erythropoietin independently from systemic hypoxia conditions. This concept emerged to include the renal oxygen extraction fraction (OFE) and intrarenal microvascular shunting with perfusion oxygen coupling in governing EPO production. The present review refines the traditional knowledge to further expand our understanding of the lung–kidney axis regulating the process of erythropoiesis and arterial oxygen content. The integrative framework demonstrates that pulmonary arterial oxygenation and renal oxygen sensing together with bone hematopoietic responses operate as a unified system which maintains both oxygen equilibrium and hematopoietic balance throughout the body. Full article