Search Results (63)

This study investigated species-specific physiological and redox responses of two coral symbiotic dinoflagellates, Cladocopium sp. and Durusdinium sp., to green-synthesized nano-selenium (SeNP) gradients, with implications for eco-friendly marine antifouling. Growth, photosynthetic pigments, antioxidant enzymes (SOD, POD, CAT), lipid peroxidation (MDA), and osmo-protectants were assessed to elucidate mechanisms. Both species exhibited a biphasic (hormetic) response, with stimulation at low concentrations and inhibition at high levels. At 50–100 mg L⁻¹, Cladocopium sp. showed enhanced growth, pigments, antioxidant activity, and osmotic regulation, with reduced oxidative stress, indicating improved redox homeostasis. In contrast, ≥150 mg L⁻¹ disrupted redox balance and suppressed growth. Durusdinium sp. displayed slower growth but maintained stable pigments, consistent antioxidant activity, and low MDA, reflecting a tolerance-oriented strategy. Overall, SeNPs synergistically regulate antioxidant systems and osmotic homeostasis to balance the intracellular redox status of symbiotic dinoflagellates, indicating their potential as antioxidant agents to improve the growth performance of symbiotic dinoflagellates in coral nursery cultivation. Full article

The shrinking of glaciers is drastically transforming headwater catchments, exposing new land surfaces and forming new water bodies, characterized by marked environmental gradients and the activation of potential geochemical hazards. The aim of this study was to characterize and compare the geochemical patterns of soil and water in areas deglaciated between 1970/1984 and 2025 within the Llaca and Gueshgue valleys of the Cordillera Blanca, Peru. Systematic soil and water sampling was conducted, and data were analyzed using descriptive statistics and multivariate techniques. The analyses revealed a clear and statistically significant geochemical differentiation between the two areas (p ≤ 0.05). Gueshgue was identified as a system in transition, exhibiting geochemical signatures of acid rock drainage (ARD), with loamy soils rich in Fe and Al, and acidic waters featuring high redox potential and elevated concentrations of SO₄²⁻, EC, Co, Cu, Mn and Mg. In contrast, Llaca exhibited greater stability, with neutral waters and sandy soils dominated by silicate weathering signatures (SiO₂) and trace elements (Al, Li, Ba, K, and Ti). These findings indicate that the impact of glacier retreat on proglacial ecosystems is heterogeneous; identifying these geochemical patterns is fundamental to establishing baseline monitoring and guiding the sustainable management of these climate-change-sensitive ecosystems. Full article

Background/Objectives: Ovarian cancer (OC) is a leading cause of cancer-related mortality in women, largely driven by late-stage diagnosis. Five-year survival is just 30% for advanced-stage (III-IV) disease but exceeds 90% for early-stage disease, underscoring the critical need for effective early detection tools. Current standard-of-care biomarkers show limited sensitivity for early-stage OC and lack specificity in symptomatic populations. Most biomarker studies in OC serum evaluate single molecular classes or compare OC to healthy controls, limiting understanding of coordinated biological alterations in circulating proteins, lipids, and metabolites in clinically relevant populations. Methods: We performed integrated multi-omics profiling of serum from a retrospective, case–control cohort of women presenting with vague abdominal symptoms (VAS), including early- and late-stage OC, borderline tumors, benign gynecologic conditions including adnexal masses, GI disorders, and healthy controls. Protein biomarkers were quantified by ELISA, lipidomic profiling was performed by untargeted LC-MS, and ganglioside and metabolomic profiling were performed by semi-targeted LC-MS with metabolite annotation performed against a curated reference library. Results: Consistent with known limitations for early-stage OC detection, CA125 and HE4 levels overlapped substantially with benign gynecologic conditions. Additional proteins also showed limited separation in their expression between early-stage OC and symptomatic controls. In contrast, OC showed unique lipid and metabolite profiles: phospholipids and glycerolipids were decreased, and sphingolipid composition was altered. Borderline and benign conditions exhibited lipid profiles that fall between healthy and OC groups, suggesting a continuum of metabolic changes rather than distinct states between OC and non-OC controls. Sphingolipid alterations included changes in ceramides and sphingomyelins, along with broader dysregulation of ganglioside profiles, including an elevated GD2;O2-to-GD1;O2 ratio. Metabolic profiling showed decreased amino acids and enriched cysteine metabolism in OC, consistent with altered redox balance, along with changes in fatty acids and acyl-carnitines, suggesting altered lipid metabolism and inflammatory mechanisms. Lower levels of glycolytic and TCA cycle intermediates in OC suggested altered mitochondrial metabolism and energetic reprogramming. Pairwise comparisons revealed a gradient of significance between groups, with differences between OC and healthy controls across lipid classes (LPC, PC, PE, TG, SM), gangliosides (GD1, GD2, GD2/GD1 ratio), and metabolites (amino acids, Cys/CySS, TCA cycle); borderlines occupied an intermediate space. Integration of these datasets revealed coordinated cross-omics relationships, identifying links between metabolite, lipid, and protein features. Together, these connections highlight structured, system-level alterations related to lipid remodeling, redox balance, immune signaling, and energy metabolism that no single modality would have revealed in isolation. Conclusions: This study presents an integrated analysis of the lipidome, gangliosome, metabolome, and protein biomarkers within a single clinically relevant symptomatic cohort enriched with multiple stages and subtypes of OC. This multi-omics framework demonstrates that molecular alterations in OC are biologically interconnected across molecular classes. While these findings are discovery-based and require independent validation prior to clinical application, they support the development of clinically deployable multi-omics biomarker strategies for early detection and potential pathways for therapeutic intervention. Full article

Mitochondria-targeting metal complexes (MTMCs) are a mechanistically distinct class of metallopharmaceuticals. Unlike first-generation platinum drugs that form nuclear DNA adducts, MTMCs exploit organelle-specific vulnerabilities such as hyperpolarised mitochondrial membrane potential (ΔΨm), elevated reactive oxygen species (ROS), limited mitochondrial DNA (mtDNA) repair capacity, and redox-dependent enzymes such as thioredoxin reductase (TrxR). We systematically searched PubMed, Web of Science, Scopus, and Google Scholar databases for studies published between 2016 and 2026, applying predefined inclusion criteria that included subcellular localization evidence and functional bioenergetic endpoints. The search identified 147 studies covering Pt(II/IV), Ru(II/III), Au(I/III), Ir(III), Os(II), Re(I), and V(IV/V) complexes and metal–organic framework nanoplatforms. Mechanistic evidence converges on four intramitochondrial target categories: inhibition of ETC (Electron Transport Chain) Complexes I/III with consequent ATP depletion; ROS overproduction, coupled with glutathione and TrxR depletion; outer mitochondrial membrane permeabilization and intrinsic apoptotic cascade activation; and mtDNA damage within a compartment limited to base excision repair. Multi-modal cell death—the co-occurrence of apoptosis, ferroptosis, necroptosis, and autophagic cell death—was a recurrent finding across the reviewed studies. This review thoroughly surveys the latest trends in MTMC drug design (metals, ligand structures, and mechanisms of action) and summarises analytical techniques for speciation, pharmacokinetics, safe monitoring, and resistance, while critically analysing translational barriers and clinical failures. To address the field’s inconsistent terminology, we introduce an explicit localization evidence hierarchy that distinguishes mitochondria-targeting complexes (through quantitative ICP-MS fractionation or co-localization with defined Pearson/Manders coefficients) from simply mitochondria-localising or mitochondria-perturbing agents, and we apply it throughout. We also point out that the idea of selectivity being purely driven by membrane voltage (ΔΨm) and thermodynamics is constrained by membrane and protein binding, as well as the transmembrane pH gradient, kinetic limitations, and demonstrated heterogeneity of cancer-cell membrane potential, and, as such, the functional mitochondrial effects must not be equated with mitochondrial accumulation. Since elemental quantification cannot distinguish intact complex from protein adducts and decomposition products, speciation-aware pharmacokinetics emerges as a prerequisite for a credible exposure–response interpretation. The translational progress will depend less on new chemotypes than on this analytical and pharmacokinetic rigour, together with organelle-level safety monitoring and biomarker-guided patient selection. Full article

One of the latest and innovative areas of research in energy is the development of thermoelectric generators (TEGs). A novel family of soft, sustainable energy harvesters, hydrogel-based renewable flexible thermoelectric generators use linked ionic, electronic, and redox processes to transform heat gradients into electrical energy. According to recent research, a hydrogel-based TEG has ionic Seebeck coefficients (S) of the order 10–40 mV K⁻¹, which are tens to hundreds of times greater than those of electronic polymers. Thermal conductivities are modest (~0.3–0.6 W/m·K), ionic conductivities typically vary from 10⁻³ to 10⁻¹ S cm⁻¹, and water-rich gels are naturally soft with elastic moduli ~10³–10⁶ Pa and elongations > 100–800%. Recent developments in the concepts, properties, working mechanism, and potential applications of hydrogel-based thermoelectric generators are the focus of this review paper. We investigate the basic transport processes, such as ionic thermodiffusion, thermoelectric ion–electron coupling, and redox-mediated potential production, that allow thermoelectric conversion in hydrogels. This review identifies bottlenecks such as poor output power under minor gradients, summarize performance parameters, and assess methods to improve efficiency. Wearable and implanted power sources, low-grade waste heat collection, and environmental monitoring are examples of promising applications. Lastly, we describe the research avenues that must be pursued in order to expedite the transition of hydrogel-based thermoelectric generators from lab tests to useful, sustainable energy sources. Therefore, the review can provide fundamental knowledge on hydrogel-based TEGs along with their working principles. Full article

A working-state model is proposed for the MnOx–Na₂WO₄/SiO₂ catalyst in oxidative coupling of methane (OCM), where a Na₂WO₄-rich surface environment forms an adaptive interphase that buffers the effective interfacial oxygen chemical potential and stabilizes cooperative MnO_x/Na–WO_x/Mn–O–W motifs. A thermodynamic-kinetic scheme is developed that relates (1) reaction-induced surface enrichment (structural stabilization), (2) oxygen spillover (damping of local oxygen gradients), and (3) Mn ↔ W redox exchange as an electron-oxygen buffer channel. Ex situ XPS/EDS/EPR data indicate a dynamically stratified near-surface region with chemically heterogeneous environments of Mn, W, and O. The W 4f region remains dominated by the W⁶⁺ contribution in the presence of a minor reduced component after OCM. In oxygen-deficient mixtures (CH₄/O₂ > 4), interfacial reconstruction becomes more pronounced: Mn-centered Mars–van Krevelen chemistry determines CH₄ activation and oxygen exchange, while the Na₂WO₄-rich phase ensures fast ion/oxygen transport. Observation of the EPR signal from W⁵⁺ ions in the tungstate matrix indicates the existence of reduced W intermediates at low oxygen potential. Optimization of C₂ selectivity and stability is suggested to require maintaining the catalyst within the selective window of effective interfacial μO by adjusting CH₂/O₂ and contact time, as well as controlling the architecture of the Na–W–O/MnO_x interfacial region. Full article

Artisanal and small-scale gold mining (ASGM) generates complex metal mixtures, yet their biological effects remain poorly characterized in high-altitude populations, where occupational exposure occurs against a hypoxic environmental background. This study evaluated 49 occupationally exposed gold miners from the Vetas–California mining district, near the Santurbán páramo in Colombia, and 25 non-exposed individuals from a comparable high-altitude area. Hair concentrations of essential and toxic elements were quantified by ICP-MS, and serum catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), oxidized glutathione (GSSG), and the GSH/GSSG ratio were assessed. Miners showed a distinct multielement profile, with a higher toxic-metal burden and a dominant mixture mainly characterized by Fe, Mn, As, Pb, Cd, and Hg. CAT and SOD activities did not differ markedly between groups, although SOD activity decreased along the main exposure gradient among exposed workers. In contrast, glutathione-related biomarkers showed a more consistent exposure-related pattern, with higher GSSG and a lower GSH/GSSG ratio, suggesting a shift toward a more oxidized glutathione redox status. Together with positive within-group associations between selected elements and the GSH/GSSG ratio, these results are consistent with a mixture-associated perturbation of glutathione redox homeostasis, with heterogeneous adaptive responses. Overall, this study supports the use of integrated biomonitoring strategies and highlights glutathione-related markers as potential indicators of early redox perturbation in high-altitude mining populations. Full article

Seasonal thermal stratification in deep reservoirs easily causes bottom hypoxia and a sharp decrease in oxidation–reduction potential (ORP), leading to the pulsed release of internal phosphorus from sediments. Under climate warming, this has become a hot issue for sustainable reservoir eutrophication control. Taking the Quanmin Reservoir in Southwest China as the research object, this study combined high-resolution profile monitoring and a Box–Behnken response surface experiment to construct a semi-empirical model coupling redox threshold effect and Arrhenius kinetics. Results showed that during thermal stratification, the water body below 18 m formed a significant redox gradient, resulting in a 21-fold vertical difference in phosphorus concentration. The response surface experiment confirmed that ORP dominates phosphorus release, and the temperature (T) effect is strictly redox-dependent: warming only promotes phosphorus release under anaerobic conditions (−50 mV), with a 26% increase in release amount when temperature rises from 10 °C to 30 °C, while temperature has a negligible effect under aerobic conditions (+30 mV). Model fitting yielded an ORP critical threshold of −17.2 ± 4.8 mV and a normalized steepness of 0.033 mV⁻¹, indicating joint control by diffusion and reaction. Based on these results, a synergistic regulatory mechanism of redox threshold and temperature was proposed, providing a quantitative basis for reservoir eutrophication management under climate warming. Maintaining ORP above −17 mV through bottom aeration can effectively block internal phosphorus release from the redox threshold perspective, though practical in situ application is constrained by aeration-induced water mixing and microbial variations, and such precise redox control may save energy, supporting the sustainability of reservoir ecosystems and long-term water quality security. Full article

Extreme high-temperature events driven by global climate change are occurring with increasing frequency, posing a serious threat to the stability of aquatic ecosystems. The Tibetan schizothoracin (Gymnocypris eckloni), a cold-water fish species endemic to the Qinghai–Tibet Plateau, is highly sensitive to temperature fluctuations and serves as an ideal model for studying the effects of climate change on fish. As a key organ for fish to perceive environmental changes, the gills’ comprehensive response mechanism has not yet been fully elucidated. This study investigated the effects of acute heat stress on the gill tissue of G. eckloni. The results showed that acute heat stress caused severe histopathological damage in the gills, including lamellar curling, epithelial cell detachment, and edema, with a significant increase in apoptosis. Biochemical analysis revealed elevated levels of cortisol, glucose, and ATPase activity in serum, as well as increased MDA content and CAT activity in the gills. Transcriptomic analysis identified 2304 DEGs. Upregulated DEGs were significantly enriched in pathways related to inflammatory response, TNF signaling, ferroptosis, and apoptosis, while downregulated DEGs were primarily involved in peroxisome metabolism, cell cycle, and steroid biosynthesis. This study confirms that acute heat stress induces structural damage and functional impairment in the gills by activating inflammatory and apoptotic pathways and disrupting redox homeostasis. It elucidates the immediate molecular and physiological responses of G. eckloni gills to acute heat stress. Follow-up experiments will be conducted at multiple time points, across different temperature gradients, and under chronic stress conditions to gain a more comprehensive understanding of the adaptive potential of high-altitude fish to climate warming, thereby providing a scientific basis for the development of conservation strategies. Full article

Chromium-related hazard in mine wastes depends strongly on oxidation state, with hexavalent chromium [Cr(VI)] representing the most mobile and toxicologically relevant chromium form. Abandoned tailings dumps can develop sharp pH and redox gradients that favour either Cr(VI) persistence or attenuation, yet field-based evidence from Eastern European post-mining sites remains limited. This study evaluates the Defor Petrila tailings dump, Jiu Valley, Romania, as a first-tier environmental hazard-screening case study based on repeated monitoring performed during 2022–2024 at twelve permanent sampling points and two local operational control samples. Field pH and redox potential (Eh), moisture, organic matter, acid-extractable Mn and Fe, pseudo-total Cr, and method-defined extractable Cr(VI) were determined. Here, pseudo-total Cr refers to chromium released by microwave-assisted acid digestion and does not represent complete decomposition of the silicate matrix, while extractable Cr(VI) refers to the operationally defined fraction obtained by alkaline extraction. In addition, a conservative redox-based prioritisation score (R_redox) was applied only as an internal ranking layer to identify sectors where Cr(VI) is more likely to persist. The upper dump sector (P1–P4) was alkaline (pH 7.5–8.2), strongly oxidising (+280 to +412 mV), and enriched in Mn and Fe, whereas the lower sector (P9–P12) was wetter, slightly acidic to near-neutral, and reducing (−59 to −10 mV). Extractable Cr(VI) reached 18.7 mg kg⁻¹ at P2 in 2024, while both control samples remained below the quantification limit. Exploratory repeated-site statistics, sector-based comparison, and correlation analysis supported a coherent association between Eh, Mn enrichment, and extractable Cr(VI), but these relationships are interpreted as spatially structured screening evidence rather than proof of a single mineralogical oxidation pathway. No direct exposure, leachability, bioaccessibility, ecotoxicity, airborne dust, water, vegetation, or biomonitoring measurements were included; therefore, the results identify priority zones for confirmatory toxicological and exposure-based assessment, not receptor-specific risk estimates. This study demonstrates that combining chromium speciation with field redox zonation can support conservative monitoring prioritisation at abandoned mine-waste sites where the toxic form of chromium may remain environmentally active. Full article

Traditional pharmacotherapy is often constrained by suboptimal bioavailability and systemic toxicity. Biomolecularly inspired nano-drug delivery systems (nano-DDS) have emerged as precise platforms to overcome these barriers by orchestrating molecular interactions at the bio-nano interface. This review systematically evaluates the molecular recognition mechanisms and biochemical principles governing nano-DDS performance. We systematically evaluate how passive targeting relies on the EPR effect—dictated by the nanocarrier’s physicochemical properties—and how active targeting exploits ligand-receptor affinity to enhance cellular uptake. Special emphasis is placed on bioresponsive strategies that utilize pathological cues—such as pH gradients, redox potential, and enzymatic activity—for intelligent, on-demand drug release. Furthermore, we discuss structure-function relationships in lipid, polymeric, and biologically derived systems, highlighting their roles in modulating therapeutic signaling in oncology and inflammatory diseases. Finally, translational hurdles and emerging AI-driven molecular design strategies are critically examined. Full article

Harnessing low-grade thermal energy from industrial processes and the environment represents an attractive route toward sustainable chemical production. In this work, we report a thermoelectrocatalytic (TE-Catal) system capable of converting small temperature gradients into chemical energy for hydrogen peroxide (H₂O₂) generation. A hybrid catalyst composed of nickel-based metal–organic frameworks (Ni-MOFs) nanoparticles integrated with carbon nanotubes (CNTs), Ni-MOFs/CNTs, was synthesized through a facile one-pot strategy. Under a temperature gradient, the thermoelectric response of the Ni-MOFs induces charge carrier generation through the Seebeck effect, enabling interfacial redox reactions that produce H₂O₂. However, rapid recombination of thermally generated carriers typically limits catalytic efficiency. By coupling Ni-MOFs with conductive CNTs networks, charge separation and transport are significantly enhanced due to the strong interfacial interaction and the high electrical conductivity of CNTs. As a result, the Ni-MOFs/CNTs nanohybrids exhibit greatly improved H₂O₂ generation rate of ~111.7 µmol g⁻¹ h⁻¹ compared with pristine Ni-MOFs (31.8 µmol g⁻¹ h⁻¹). Thermoelectric electrochemical measurements confirm that the CNT incorporation effectively promotes carrier migration and suppresses recombination. This study demonstrates the potential of MOF-based thermoelectric nanostructures for transforming waste heat into valuable chemical products. Full article

Metal(loid) contamination is a persistent environmental stressor in terrestrial ecosystems, yet field-based evidence linking cumulative soil contamination to physiological responses in social insects remains limited. In this study, we investigated an industrial pollution gradient by measuring soil concentrations of potentially toxic elements across multiple sites and integrating multi-element exposure into a cumulative pollution index. Two ant taxa, Lasius niger (Linnaeus, 1758) and Tetramorium cf. caespitum (Linnaeus, 1758), were sampled using a standardized field design, and biochemical endpoints were assessed to characterize antioxidant defense, thiol-based redox status, oxidative damage, and neuroenzymatic responses. Ant homogenates were analyzed spectrophotometrically for antioxidant enzymes, reduced glutathione, lipid peroxidation, protein oxidation, and acetylcholinesterase activity compared with the local low-contamination reference site. In addition, PLI showed positive site-level associations with multiple biomarkers, suggesting coordinated covariation between cumulative soil contamination and biochemical responses. Because these analyses were based on site-level mean values and direct tissue metal burdens were not measured, the findings should be interpreted as field-based associations rather than evidence of direct internal dose–response or metal-specific causality. These findings suggest that cumulative soil metal(loid) contamination is linked to integrated oxidative and neuroenzymatic stress responses in ants and support the use of ant-based biomarkers as informative tools for ecological biomonitoring under field conditions. Full article

Chimonobambusa utilis is a dominant bamboo species in China, yet its leaves remain an underutilized resource despite their significant bioactive potential. To elucidate the metabolic reprogramming of Ch. utilis leaves across an elevational gradient and its link to antioxidant phenotypes, we integrated widely targeted metabolomics with redox profiling of leaves collected from 1150, 1600, and 2000 m in the Qingba Mountains. The mid-elevation (1600 m) group exhibited the most robust antioxidant capacity and the highest total flavonoid content. Metabolomic analysis identified 3113 metabolites across 13 classes, with flavonoids (604 compounds, 22.7% of total abundance) emerging as the predominant secondary metabolites. Pairwise comparisons revealed 1716 differentially accumulated metabolites (DAMs). KEGG enrichment indicated that while the low-elevation (1150 m) group prioritized primary metabolism and upstream phenylpropanoid branches, the high-elevation (2000 m) group was associated with photoprotection and defense responses. In contrast, the mid-elevation environment optimized the flux toward flavonoid biosynthesis while maintaining steady metabolic supply. HPLC quantification further confirmed that key markers—vitexin, hyperoside, orientin, and luteoloside—peaked at 1600 m. Correlation analysis between 423 differential flavonoids and antioxidant indices demonstrated that distinct radical-scavenging activities are driven by specific flavonoid structural motifs. Overall, altitude-driven metabolic remodeling, characterized by a mid-elevation advantage for flavonoid accumulation, dictates the antioxidant plasticity of Ch. utilis leaves. Full article

Mangroves rank among the most productive ecosystems on Earth, yet they are increasingly threatened by climate change and the expansion of agricultural land use. Among agricultural pollutants reaching coastal environments, glyphosate-based herbicide formulations (GBHFs) are of particular concern owing to their widespread application and environmental persistence. This study evaluated the phytotoxic effects of a GBHF (commercial product Velfosato, 48% active ingredient) on Rhizophora mangle L. seedlings under controlled experimental conditions simulating the intertidal regime of the collection site. Propagules were collected from the Los Petenes Biosphere Reserve (Campeche, Mexico), established in experimental tanks containing mangrove soil, and grown until uniform seedling development was achieved. Once seedlings reached uniform development, they were exposed to nominal concentrations of 0.003, 0.03, 0.3, 3.0, and 10 mg L⁻¹ of the formulation dissolved in interstitial water. The experiment followed a completely randomized design (three replicate tanks per treatment plus a triplicate control; n = 1170 seedlings total). All inferential tests used the tank as the experimental unit (n = 3 per treatment). Total chlorophyll concentration was significantly lower in treated seedlings than in the control across all tested concentrations (ANOVA F_5,12 = 4.55, p = 0.015). Height growth rates were significantly reduced at concentrations ≥ 3 mg L⁻¹ (F_5,12 = 6.84, p = 0.003). Lenticel number increased significantly at the two highest concentrations (F_5,24 = 3.63, p = 0.014). Mangrove soil exhibited significant increases in pH and decreases in redox potential across the concentration gradient (p < 0.001 and p = 0.001, respectively). These findings indicate that sublethal exposure to a GBHF is associated with alterations in key ecophysiological processes and soil physicochemical conditions in R. mangle seedlings under controlled conditions, highlighting the sensitivity of early developmental stages to GBHF exposure. Full article