Search Results (2,889)

To address cathode passivation, performance deterioration, and toxic stress during the removal of hexavalent chromium [Cr(VI)] in biocathode microbial fuel cells (MFCs), this study constructed nanomaterial-hybridized biocathodes to improve electricity generation and Cr(VI) removal in MFCs. Reduced graphene oxide (rGO), nano-iron sulfide (nano-FeS), and rGO/nano-FeS were separately hybridized with biocathodes to systematically investigate the effects of different hybridized biocathodes on the performance of MFCs for Cr(VI)-containing wastewater treatment. The results showed that the FeS group exhibited the best Cr(VI) removal capability, with a maximum removal kinetic constant of 0.184 h⁻¹, which was 3.60 times that of the Control group, and showed the smallest performance decline after three consecutive cycles. Mechanistic analysis indicated that nano-FeS promoted the transformation of Cr(VI) into Cr(III) and Cr(0) through its strong adsorption and reducing capacities; it also enhanced biofilm cell activity and the protein/polysaccharide ratio in extracellular polymeric substances; furthermore, it shaped a multi-taxon-dominated microbial community capable of Cr(VI) tolerance and reduction and enhanced the associated metabolic functions, thereby improving resistance to Cr(VI) stress and effectively alleviating cathode passivation. In contrast, rGO tended to enhance biocathode conductivity and electricity generation in MFCs, with the rGO + FeS group achieving the highest power density output of 51.54 ± 3.62 mW/m², which was 1.22 times that of the Control group, as well as the smallest decline in power density after three consecutive cycles. Overall, nanomaterial hybridization reshaped interfacial electron transfer and microbial stress resistance in biocathodes, enabling efficient Cr(VI) removal and stable electricity generation, and providing a new strategy to construct long-term stable bioelectrochemical systems for heavy metal-containing wastewater treatment. Full article

Widespread environmental contamination by per- and poly-fluoroalkyl substances (PFAS) has driven the phaseout of traditional long-chain compounds; however, the toxicity of their highly mobile, short-chain replacements to aquatic microorganisms remains less well characterized. This study compared the toxicity of perfluoroalkyl carboxylic acid (PFCA): long-chain perfluorooctanoic acid (PFOA, C8) and the short-chain perfluorobutanoic acid (PFBA, C4) in two structurally distinct microalgae, Prymnesium parvum and Chlorella sorokiniana. P. parvum was more sensitive to PFAS exposure than C. sorokiniana, with significant growth inhibition occurring at 25–50 mg/L and complete mortality at 100 mg/L, whereas C. sorokiniana exhibited significant effects at concentrations ≥200 mg/L. PFBA exhibited greater toxicity than PFOA in both species, with IC₅₀ values of 25.81 and 64.30 mg/L, respectively, in P. parvum and 101.4 and 277.1 mg/L, respectively, in C. sorokiniana. PFBA induced reactive oxygen species (ROS) generation, lipid peroxidation, and significantly increased in cell volume and chlorophyll content in P. parvum, whereas C. sorokiniana exhibited oxidative responses primarily at higher concentrations and no significant changes in cell dimensions or chlorophyll content. The responses indicate that oxidative stress is an important component of PFCA toxicity and sensitivity differs substantially between microalgal species. The contrasting responses may be associated with differences in cellular structure and physiology, although the underlying mechanisms require further investigation. Overall, PFCA toxicity was both compound- and species-dependent, and the greater toxicity of PFBA under the tested conditions demonstrates that short-chain replacement PFCAs should not be assumed to have lower biological toxicity than their long-chain counterparts. Full article

Per- and polyfluoroalkyl substances (PFAS) are widely detected in aquatic environments, and their bioaccumulation, trophic magnification, and ecotoxicity have raised increasing concern. However, critical knowledge gaps remain regarding how differences in their molecular structures influence these processes and the mechanisms underlying such effects. This review synthesizes the current knowledge of the physicochemical properties, bioaccumulation, trophic magnification, and toxicity of PFAS in aquatic environments, with particular emphasis on the effects of the carbon-chain length, functional-group type, and acid or salt form. The current evidence generally indicates that long-chain PFAS exhibit higher bioaccumulation, trophic magnification, and toxicity than short-chain PFAS, largely because of their enhanced hydrophobicity, stronger protein-binding affinity, and slower elimination rates. As two major PFAS subclasses, perfluoroalkyl sulfonates (PFSAs) generally show higher bioaccumulation and toxicity than perfluoroalkyl carboxylates (PFCAs). For example, the bioaccumulation factor of perfluorooctane sulfonate (PFOS) is approximately two- to three fold higher than that of perfluorooctanoic acid (PFOA). Some ether-containing PFAS, developed as safer alternatives, also exhibit concerning ecological hazards, particularly a high potential for trophic magnification. In addition, acid form PFAS generally accumulate more readily and induce more severe toxic effects than their corresponding salt forms. These findings highlight the need to further improve structure-based frameworks for PFAS ecological risk assessment. Full article

Per- and polyfluoroalkyl substances (PFAS) are persistent, structurally diverse contaminants whose ecological hazard assessment remains challenging, particularly for primary producers. Conventional growth-based algal bioassays often overlook sublethal responses associated with chronic exposure. Here, we developed a 7-day multigenerational bioassay using the freshwater diatom Cyclotella meneghiniana that integrates chlorophyll fluorescence (photosynthetic biomass) and lipid accumulation (oxidative stress and carbon reallocation) as complementary endpoints. Ten PFAS spanning carbon chain lengths from C4 to C11 and representing both perfluoroalkyl carboxylates and sulfonates were evaluated under identical nominal exposure conditions. Distinct structure-dependent toxicity patterns emerged. Long-chain perfluoroalkyl carboxylic acids elicited the strongest responses, whereas short-chain compounds produced no measurable effects. Among the sulfonates, PFHxS reduced chlorophyll fluorescence with limited effects on lipid accumulation, whereas PFOS produced no measurable response. Exploratory species sensitivity distribution analyses indicated compound-specific differences, although predicted no-effect concentrations should be interpreted cautiously because they combine literature-derived growth endpoints with endpoint-specific values generated in this study. This dual-endpoint diatom bioassay provides a proof-of-concept platform for structure-informed PFAS hazard ranking rather than regulatory toxicity assessment. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent, surface-active contaminants for which soil represents the largest terrestrial reservoir. This review synthesizes a rapidly expanding but fragmented body of literature in order to reframe PFAS not merely as a groundwater transport problem but as a systemic stressor of soil health, drawing together their reported effects on the chemical, physical and biological properties of soils and giving particular attention to the calcareous, alkaline, carbon-poor and seasonally dry soils of the Mediterranean. The reviewed evidence suggests that, chemically, PFASs perturb the coupled carbon and nitrogen cycles rather than the bulk soil reaction, transiently stimulating and then depressing organic carbon turnover, drawing down the dissolved organic carbon pool and disturbing nitrification, while their retention and bioavailability are governed chiefly by organic carbon, chain length and pH. Physically, the surfactant character that defines these molecules lowers the surface tension of soil water and concentrates PFASs at the air–water interface, so that in unsaturated and drought-prone soils much of the burden is retained and then released episodically, most clearly on rewetting after dry periods. Biologically, the literature consistently reports dose-dependent declines in microbial viability, diversity and enzyme activity, alongside toxicity to earthworms and other soil fauna, with sensitivity strongly modulated by soil texture and organic matter. Across all three domains, the Mediterranean emerges as both potentially vulnerable and conspicuously understudied, the available data being clustered in a few western countries and effectively absent for much of the eastern and southern basin, so that the regional assessment offered here rests largely on mechanistic inference rather than on direct observation. The review argues that these coupled mechanistic and geographic gaps define an urgent, region-specific research agenda for the protection of soil health. Full article

Objectives: This study aimed to explore the cellular injury phenotypes induced by outer membrane vesicles (OMVs) from uropathogenic Escherichia coli (E. coli, UPEC) and Proteus mirabilis (P. mirabilis, P. m) in human renal tubular epithelial HK-2 cells in vitro. Introduction: In urological practice, UPEC and P. mirabilis are representative pathogens of uncomplicated and complicated UTIs, respectively. Both are Gram-negative bacteria, and a notable feature of these bacteria is their ability to secrete OMVs. OMVs are nanoscale vesicles containing lipopolysaccharides (LPS), phospholipids, peptidoglycan, nucleic acids, and various virulence factors such as proteases and toxins. OMVs serve as effective carriers, delivering these toxic substances to host cells, triggering inflammatory responses, cellular damage, and ultimately cell death. Methods: In this study, we cultured standard pathogenic strains of E. coli and P. mirabilis in lysogeny broth (LB) medium until they reached the logarithmic growth phase. OMVs were isolated and identified. The uptake of OMVs by HK-2 cells was observed in vitro, and we evaluated the cytotoxic effects of both types of OMVs by measuring cell viability, oxidative stress, membrane permeability, mitochondrial function, and organelle morphology. Results: The results demonstrated that OMVs from both bacterial strains were efficiently internalized by HK-2 cells. Both OMVs induced oxidative stress, decreased antioxidant capacity, disrupted membrane permeability, and damaged mitochondrial function, leading to cell injury. Interestingly, while the two types of OMVs caused comparable cytotoxicity in terms of cell viability, oxidative stress and mitochondrial membrane potential, they produced distinct patterns of mitochondrial ultrastructural injury: P. mirabilis OMVs primarily caused mitochondrial structural deformation and blurred cristae, while E. coli OMVs led to mitochondrial swelling, cristae breakage, and vacuolization. These findings provide phenotypic evidence and experimental clues for understanding OMV-associated renal tubular epithelial injury caused by different uropathogens. Full article

Climate change is increasing the frequency and severity of abiotic stresses, including salinity, drought, heat, and heavy metal toxicity, which strongly threaten productivity, quality, and market value in horticultural crops. Although plant biostimulants have been widely reviewed in agronomic crops, their role in horticultural systems remains less comprehensively synthesized, particularly across different crop groups, stress types, application methods, and molecular response mechanisms. This review addresses this gap by systematically compiling current evidence on the use of biostimulants to improve abiotic stress resilience in horticultural crops, with particular emphasis on morphological, physiological, biochemical, and recently emerging molecular responses, especially transcriptomic evidence with supporting metabolomic information where available. Publications were retrieved from the Web of Science Core Collection using two searches covering 2016–2025 for morphological/physiological responses and 2021–2025 for molecular/genetic responses. Of 780 records initially identified, 134 studies met the inclusion criteria. Across these studies, the most frequently evaluated biostimulants were seaweed extracts, humic and fulvic substances, protein hydrolysates, and microbial inoculants, particularly PGPR and AMF. Biostimulant application consistently improved stress tolerance by enhancing antioxidant capacity, osmotic adjustment, nutrient use efficiency, cell wall strengthening, and hormonal regulation. Foliar applications were frequently used for rapid mitigation of drought- and heat-induced canopy-level physiological responses, whereas soil/root-zone application was more common for salinity and heavy metal stress. Emerging molecular evidence, dominated by transcriptomic studies and supported by limited metabolomic data, indicates that biostimulants may induce molecular priming through stress-responsive gene networks and associated metabolic adjustments. Overall, biostimulants show strong potential to improve abiotic stress resilience in horticultural crops, but broader adoption is constrained by variable efficacy, limited mechanistic validation, and inconsistent regulatory frameworks. Future research should prioritize multi-environment validation and functional genetics to support more reliable and targeted biostimulant use. Full article

This research investigated the extraction and purification of melanin from the Ophiocordyceps sinensis TZ8-1; characterized its structural properties; and evaluated its safety, photoprotective efficacy, and ability to mitigate heavy metals. The results demonstrated that the spectral features of TZ8-1 melanin were consistent with those of synthetic melanin, confirming its classification as typical eumelanin. The safety assessment indicated that TZ8-1 melanin has relatively low toxicity to four types of normal human cells, and based on the results of acute oral toxicity tests, this substance showed high safety for experimental animals. Photoprotection studies showed that TZ8-1 melanin effectively suppressed reactive oxygen species (ROS) generation and significantly improved cell viability post-ultraviolet B (UVB) exposure. Heavy metal mitigation experiments showed that TZ8-1 melanin reduced malondialdehyde (MDA) levels, increased glutathione (GSH) concentrations, and enhanced cell survival rates in heavy metal-exposed conditions. Full article

Copper nanoparticles (Cu-NPs) are widely used in aquaculture for their growth-promoting and immunoenhancing properties. However, excessive or over-accumulated Cu-NPs in aquaculture water cause toxicity through waterborne immersion. To explore the toxicity effects of waterborne Cu-NPs on yellowtail kingfish (Seriola aureovittata), a 7-day exposure experiment comprising a control group (no Cu-NPs), a low-concentration group (0.120 mg/L), and a high-concentration group (0.384 mg/L) was conducted, followed by a 7-day recovery period without Cu-NP stress. Exposure to Cu-NPs significantly elevated antioxidant enzyme activities (GSH-Px, Cu/Zn-SOD) and thiobarbituric acid reactive substances (TBARS) level in liver and posterior kidney, indicating significant oxidative stress. In the liver, levels of epinephrine and diacylglycerol were significantly upregulated, the cAMP signaling pathway was disrupted, and the NF-κB signaling pathway was activated, along with the downregulation of ap-1 and erk1-2 and upregulation of gadd45β, reducing cell proliferation and viability. These alterations resulted in hepatocellular vacuolation and blurred outlines of hepatic lobules. In the gill, high-concentration Cu-NPs activated oxidative phosphorylation, phagosome, and cell-adhesion molecules pathways and downregulated genes related to cell proliferation, adhesion, and tight junctions (i.e., l1cam, camd1, cntn1, cdh2, and nectin1), leading to cellular vacuolization and epithelial separation in histology. These changes disrupted osmotic balance and significantly upregulated Na⁺/K⁺-ATPase activity. All histological damages were not fully recovered within the tested recovery period. Therefore, under conditions of continuous exposure, the concentration of Cu-NPs used for juvenile yellowtail kingfish in aquaculture should be kept below 0.120 mg/L, with a recovery period exceeding 7 days. These results reveal the toxicity mechanisms of Cu-NPs and provide a scientific basis for establishing safe application guidelines in yellowtail kingfish aquaculture. Full article

Environmental chemical exposures are increasingly recognized as contributors to metabolic dysfunction, particularly when they occur as chronic, low-dose mixtures rather than as isolated high-dose toxicants. However, current approaches often focus on exposure intensity, single-compound hazard or isolated biomarker associations, and provide limited explanation for why individuals with comparable exposure profiles may develop markedly different metabolic outcomes. This semi-systematic review proposes an Exposure–Adaptive Capacity (EAC) framework to interpret the metabolic consequences of environmental chemical mixtures through the interaction between exposure burden and host adaptive capacity. A structured literature search covered PubMed/MEDLINE, Scopus and Web of Science records published through 30 June 2026; a reviewer-triggered PubMed/MEDLINE update was executed on 30 July 2026 using harmonized British and American dyslipidaemia/dyslipidemia terms, explicit eligibility domains and evidence-mapping procedures. The review integrates epidemiological, mechanistic, toxicological and translational evidence related to environmental chemicals, metabolic dysfunction, mitochondrial impairment, oxidative stress, inflammation, endocrine disruption, metabolic resilience and biomarkers. The evidence indicates that several chemical classes, including per- and polyfluoroalkyl substances, bisphenols, phthalates, pesticides, persistent organic pollutants and selected metals, converge on mitochondrial bioenergetics, redox regulation, inflammatory signalling, endocrine and nuclear receptor activity, nutrient-sensing networks and adipose tissue function. The EAC framework defines exposure burden as the cumulative biological pressure imposed by chemical mixtures and adaptive capacity as the organism’s functional ability to buffer, compensate for or recover from exposure-induced metabolic stress. To make the framework empirically testable, we specify measurable domains for exposure burden, adaptive capacity and EAC mismatch, and distinguish biomarkers of exposure, early biological effect, adaptive capacity, metabolic dysfunction and vulnerability. A quotient-based expression is retained only as a heuristic representation, while empirical testing is proposed through exposure-by-adaptive-capacity interaction models and complementary multidimensional approaches. The framework provides a structured basis for future exposomic, epidemiological and translational studies by shifting attention from exposure alone to the balance between environmental pressure and biological resilience. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent synthetic chemicals of global concern. While most research has focused on their occurrence and toxicity, far less attention has been paid to their impacts on the global carbon cycle. This review synthesizes current evidence on how PFASs influence carbon cycling across soils, aquatic systems, and the atmosphere. In soils, PFASs alter organic carbon inputs by affecting plant biomass and root exudates and shift microbial community composition and enzyme activities, thereby modulating organic matter decomposition. In aquatic ecosystems, PFASs biologically impair carbon sequestration by inhibiting plankton, and abiotically interact with extracellular polymeric substances to prolong the cycling of dissolved organic carbon. The atmosphere acts as a key mediator as follows: thermal treatment of PFASs generates perfluorocarbons, potent greenhouse gases that exacerbate global warming and further disturb carbon cycling. Despite clear disruptive effects, major knowledge gaps remain. Future research should use quantitative structure–property relationship modeling to assess PFAS alternatives (e.g., PFHxS), and employ advanced molecular tracking (e.g., isotopic labeling, NanoSIMS) and machine learning to unravel nonlinear PFAS–carbon dynamics. Improved detection technologies are needed to identify greenhouse gas byproducts from PFAS thermal treatment. Ultimately, deploying high-resolution flux observation networks and integrating PFAS dynamics into Earth system models and carbon-accounting frameworks are critical for predicting carbon–climate feedback and supporting global carbon neutrality goals. Full article

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects mainly peripheral joints because of inflammation of the synovial membrane. Current treatments, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids, although effective, are associated with high costs and several adverse effects. In this context, natural products have emerged as promising alternatives because of their potential therapeutic effects and lower toxicity. The objective of this review was to identify and evaluate natural substances with potential applications in RA treatment on the basis of studies published between 2015 and 2020. A literature search was conducted in SciELO, PubMed, and Google Scholar using the keywords “rheumatoid arthritis”, “treatment”, “toxicity”, and “natural products”. Additionally, we applied in silico methods to predict pharmacokinetic and toxicological parameters using ADMET Predictor^® (Simulation Plus) and compared the results with those of commercial drugs such as diclofenac, ibuprofen, and naproxen. Target fishing (reverse docking) was also performed to identify possible molecular targets related to RA. Seven natural compounds were identified, mostly evaluated through in vivo studies. Among them, paeoniflorin, quercetin, resveratrol, and celastrol are in clinical phases and present potential as RA treatments. In silico analysis highlighted curcumin, tetramethylpyrazine, and resveratrol as the most promising candidates, with ADMET profiles comparable or superior to those of current NSAIDs. In conclusion, natural products represent viable alternatives for RA therapy. However, further studies are essential to better understand their safety, pharmacokinetics, and drug interactions to ensure their clinical applicability. Full article

Background/Objectives: Synthetic cathinones are a rapidly evolving class of new psychoactive substances whose structural diversity complicates toxicological risk assessment. Methylenedioxy cathinones occupy a pharmacological space between MDMA-like entactogens and more dopaminergic stimulant cathinones, but their direct cardiac liabilities remain poorly characterized. This study aimed to compare the cardiotoxic and neurobehavioral profiles of methylone, butylone, pentylone and their N,N-dimethyl analogues, and to determine how alkyl-chain extension and terminal amine substitution shape functional toxicity. Methods: Wild-type short-fin zebrafish (Danio rerio) embryos were used as a multiparametric New Approach Methodology. Cardiac rhythmicity was assessed in 3 days post-fertilization embryos after acute exposure to methylone, butylone, pentylone, dimethylone, dibutylone, dipentylone, dihexylone and diheptylone by high-speed video microscopy and dynamic pixel-based analysis, focusing on atrial chronotropy and atrioventricular conduction. Basal locomotor activity was evaluated in 5 days post-fertilization eleutheroembryos over 120 min using automated video tracking. Results: Negative chronotropy increased with alkyl-chain extension, with the monoalkyl subset following the rank order methylone < butylone < pentylone. Among dialkyl analogues, dihexylone and, especially, diheptylone produced the strongest atrial-rate inhibition. AV conduction impairment was more heterogeneous but became prominent among higher-liability analogues, with diheptylone showing the lowest AV-block midpoint descriptor and complete lethality at 1000 µM. Locomotor profiling revealed predominantly hypoactive phenotypes, with sustained late-phase inhibition especially for dipentylone, dihexylone and diheptylone. Conclusions: Alkyl-chain extension and terminal amine substitution shaped cardiac and neurobehavioral toxicity in a structure-dependent manner. The zebrafish workflow provides a structure-oriented framework for prioritizing emerging methylenedioxy cathinones with comparatively higher functional cardiac liability. Full article

To cope with severe seasonal changes in climate and food availability, colonies of Apis mellifera L. generate two distinct worker phenotypes during winter and summer. The aim of this research was to evaluate the effect of oral exposure to insecticides on the toxic susceptibility of winter and summer honeybee workers (Apis mellifera L.) under laboratory conditions. In this work, under all tested conditions and seasons, emamectin benzoate was the most toxic compound and used as the standard (Toxicity Index = 100) for comparison with other compounds. It had the lowest LC₅₀ (Lethal Concentration required to kill 50% of the tested honeybees) values, which decreased to 0.004 mg/L in winter bees after 48 h following oral exposure. Sulfoxaflor had moderate toxicity, and indoxacarb was the least toxic to honeybees. The results also revealed that the toxic effect was time-dependent, with lethal concentrations at 48 h significantly lower than those at 24 h. In addition, seasonal effects play a role; winter honeybees were, overall, more sensitive to the treatments than summer honeybees. Under the conditions of this study, it can be concluded that emamectin benzoate was the most toxic substance and indoxacarb the least toxic. Toxicity increased with exposure time. Winter honeybees showed greater sensitivity than summer honeybees. A field-relevant Hazard Quotient (HQ) analysis further indicated that indoxacarb, despite its lower acute toxicity, exhibited the narrowest margin relative to field-recommended spray concentrations, highlighting the value of incorporating field-relevant exposure metrics alongside LC₅₀-based rankings in pollinator risk assessment. It is worth clarifying that this narrower margin reflects indoxacarb’s higher field-recommended application rate relative to its LC₅₀, rather than a greater intrinsic toxicity than emamectin benzoate, and the two aspects of risk (intrinsic toxicity vs. use-rate-based field risk) should be interpreted separately. Full article

This study analyzed the content of polluting and toxic elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in the cadastral municipalities immediately surrounding the mining and metallurgical complex Bor in Serbia. The soil is exposed to hazardous substances due to historical pollution. Soil pollution at different locations was assessed based on the measured concentration of metals and the contamination factor (Cf). The increased content of the toxic metals was determined mostly for copper and arsenic. Three types of different plants were used in order to reduce the content of toxic metals in the contaminated mining and metallurgical land. The results showed that these plants (barley Hordeum sativum, sugar grazer Sorghum bicolor, and hybrid BMR 333 Sudan grass) were capable of growing and accumulating metals in plants at copper-mined and metallurgical sites. Full article