Search Results (251)

Enhanced silicate rock weathering (ESRW) has been proposed as a promising carbon dioxide removal strategy, yet its carbon sequestration pathways, durability, and ecosystem dependence remain incompletely understood. Here, we synthesize evidence from field experiments, observational studies, and modeling to compare ESRW-induced carbon dynamics across forest and cropland ecosystems using a unified SOC–SIC dual-pool framework. Across both systems, ESRW operates through shared geochemical processes, including proton consumption during silicate dissolution and base cation release, which promote atmospheric CO₂ uptake. However, carbon fate diverges markedly among ecosystems. Forest systems, characterized by high biomass production, deep rooting, and strong hydrological connectivity, primarily favor biologically mediated pathways, enhancing net primary productivity and mineral-associated organic carbon (MAOC) formation, while facilitating downstream export of dissolved inorganic carbon (DIC). In contrast, intensively managed croplands more readily accumulate measurable soil inorganic carbon (SIC) and soil DIC over short to medium timescales, particularly under evapotranspiration-dominated or calcium-rich conditions, although SOC responses are often moderate and variable. Importantly, only a subset of ESRW-driven pathways—such as MAOC formation and secondary carbonate precipitation—represent durable carbon storage on decadal to centennial timescales. By explicitly distinguishing carbon storage from carbon transport, this synthesis clarifies the conditions under which ESRW can contribute to climate change mitigation and highlights the need for ecosystem-specific deployment and monitoring strategies. Full article

Plant organic cation transporters (OCTs) are involved in a variety of beneficial biological processes, such as cadaverine transfer in plants and soil, and play an active role in the formation of plant stress resistance. In this study, 52 OCT family genes were identified in tomato, and comprehensive bioinformatics analyses of these numbers, such as promoter cis-acting elements, gene mapping and collinearity, protein characterization and phylogenetic analysis. By analyzing the expression of tomato OCT family genes under cold and salt stresses using transcriptome data and qRT-PCR experiments, a key gene regulating cold stress tolerance, SlOCT20, was identified. Subcellular localization experiments indicated that SlOCT20 was mainly localized in the cell membrane. When the SlOCT20 gene was silenced in tomato, the tolerance to cold stress was significantly reduced and oxidative stress was aggravated, indicating that this gene positively regulates the tolerance to cold stress in tomato. Full article

Floods and wildfires are two extreme environmental events with significant yet different impacts on soil health and on two particularly important soil pollutants, heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs), which are directly associated with ishytoxic properties and their ability to enter the food chain. The present study includes a methodological approach that was based on a literature review of published studies conducted worldwide regarding these two phenomena. The main forms of both pollutants, their possible sources and inevitable deposition onto the soil surface, along with their behavior–transport–mobility, and their residence time in soil were investigated. Furthermore, the changes that both HMs and PAHs induce in the physicochemical properties of post-flood and post-fire soils (in soil pH, Cation Exchange Capacity (CEC), organic matter content, porosity, mineralogical alterations, etc.), are investigated after a literature review of various case studies. Wildfires, in contrast to floods, can more easily remove large quantities of heavy metals into the soil ecosystem, most likely due to the intense erosion they cause. At the same time, floods appear to significantly burden soils with PAHs. In wildfires, the largest mean increases were observed for Mn (386%), Zn (300%), and Cu (202%). In floods, Pb showed the highest mean increase (534%), with Cd also rising substantially (236%). Regarding total PAHs, mean post-event concentrations reached 482.3 μg/kg after wildfires, compared to 4384 μg/kg after floods. Changes in the structure and chemical composition of flooded and burned soils may also affect the mobility and bioavailability of the pollutants under study. Overall, these two phenomena significantly alter soil quality, affecting both ecological processes and potential health impacts. Full article

Metformin, a 60-year-old biguanide and cornerstone of type 2 diabetes therapy, continues to challenge and inspire modern pharmaceutical science. Despite its chemical simplicity, metformin displays highly complex pharmacokinetic and pharmacodynamic behavior driven by transporter dependence, luminal activity, and formulation-sensitive exposure. Originally regarded as limited by low permeability and incomplete absorption, metformin has emerged as a paradigm for gut-targeted therapy, controlled- and delayed-release systems, and personalized pharmaceutics. Growing evidence has repositioned the intestine, rather than systemic plasma exposure, as a major site of action, highlighting the central role of organic cation transporters and multidrug efflux systems in determining efficacy, variability, and gastrointestinal tolerability. Beyond metabolic control, insights into transporter regulation, pharmacogenetics, microbiome interactions, and manufacturing quality have expanded metformin’s relevance as a model compound for contemporary drug development. Advances in formulation design, quality-by-design manufacturing, and regulatory control have further reinforced its clinical robustness, while repurposing efforts in oncology, immunometabolism, and regenerative medicine underscore its translational potential. This review integrates mechanistic pharmacology, formulation science, and clinical translation to position metformin not merely as an antidiabetic agent, but as a didactic model illustrating the evolution of pharmaceutics from molecule-centered design to system-oriented, precision-driven therapy. Full article

Antarctica’s pristine environment and geographical isolation make it an ideal location for conducting research on the global transport and fate of pollutants. Given its unique environmental characteristics, research on this continent is essential for identifying and characterizing the various types of pollution and understanding their transport dynamics. This study employs a comprehensive analytical approach to examine the physico-chemical and chemical characteristics of water samples collected from catchments at the Lions Rump headland, including assessments of pH, specific electrical conductivity, total organic carbon, inorganic analytes (anions, cations, metals and metalloids), and polycyclic aromatic hydrocarbons (PAHs). The results showed that stream waters exhibited neutral to slightly alkaline conditions (pH 7.0–8.1) and relatively high conductivity, indicating a significant contribution of volcanic and marine inputs. TOC concentrations remained low (<2 mg L⁻¹), while elevated levels of Cl⁻ and SO₄²⁻ reflected the strong imprint of halogen deposition. PAHs were detected at low concentrations (41.5–67.4 ng/L), with their distribution pointing to long-range atmospheric transport as the dominant source and additional evidence of re-emission from sediments. The obtained results fill gaps in knowledge about the chemical composition of water, including the levels of potentially toxic substances in areas of Antarctica that are not directly influenced by research stations. Full article

Nitrated monoaromatic hydrocarbons (NMAHs) are emerging air pollutants commonly found in biomass burning (BB) and anthropogenic aerosols (AA). Despite their frequent deposition into aquatic systems, their ecotoxicity is still poorly understood. This study evaluates the toxicity of BB and AA aerosol extracts and their main NMAH constituents (nitrocatechols, nitrophenols, and nitrosalicylic acids) using in vitro (cellular uptake, cytotoxicity) and in vivo (algal growth inhibition, zebrafish embryo development) bioassays. Polar aerosol extracts showed higher toxicity than nonpolar ones, with stronger interaction via zebrafish organic anion Oatp1d1 than organic cation Oct1 transporter, indicating selective uptake. NMAHs and their relevant mixtures showed similar toxicity patterns as BB water extract, so NMAHs were identified as contributors to aerosol toxicity. Nitrocatechols stand out for their toxicity, showing the highest chronic toxicity in algae (IC₅₀: 0.6–1.1 mg/L) and acute cytotoxicity in fish cells (IC₅₀: 2.0–4.1 mg/L), possibly because they dominated the NMAHs composition of aerosols (BB: 80.6%; AA: 79.8%). Sublethal NMAH concentrations caused developmental disorders and altered lipid homeostasis in zebrafish embryos, indicating early physiological stress on higher organisms. These findings reveal NMAHs as significant ecotoxic components of BB and AA emissions which may pose an increasing threat to aquatic ecosystems following atmospheric deposition. Full article

Ionomers are promising materials because ionic interactions and their reversible clustering provide sensitivity to stimuli and facilitate energy dissipation, polymer miscibility, and ion transport. The existence of a wide variety of interacting ionic groups and their associated macromolecular structures provides the basis for considering the supramolecular organization of ionic polymeric materials as a factor determining the emergence of specific properties. The main structural elements of ionomers are ionic clusters, and the properties of ionomers are determined by their sizes and size distribution. Ionomers are attractive for use in composites, actuators, coatings, dyed textiles, adhesives, shape-memory and self-healing materials, water purification membranes, and ion-exchange membranes for fuel cells and batteries. This paper presents a review of the macromolecular structure and supramolecular organization of ionomers and their properties, depending on the basis of their ionic functionalization. The ionic functions of ionomers are determined primarily by the type of ion (cations or anions) that serves as the basis for their functionalization. Ionomers containing both anionic and cationic pendant ions are considered, with attention given to the influence of the nature of the counterions used on the properties of ionomers. Full article

There remains an urgent need for knowledge regarding the molecular and genetic mechanisms in Aedes aegypti to support the fight against mosquito-borne illness, one of these areas being xenobiotic transport. If xenobiotic transport is disrupted, the accumulation of foreign molecules can reach toxic levels, leading to mortality. Therefore, transport by transmembrane proteins is an important consideration in the processes that govern mosquito metabolism and survival. We have identified six genes we speculate to be novel organic cation transporters (OCTNs) or organic cation transporters (OCTs) in Ae. aegypti. To measure the potential function of these transporters, female Ae. aegypti were injected with a blood meal size bolus of saline containing the xenobiotics Alizarin Yellow GG, Alizarin Yellow R, and Olsalazine and then clearance was quantified. mRNA expressions were analyzed 2 h and 24 h post injections in relation to xenobiotic exposure. Our findings demonstrate that xenobiotics had limited effect on the putative transporter expression profiles, but the molecular structure of the xenobiotics dramatically modified the volume and composition of the excreted materials, as well as changing the mortality. Overall, the mechanisms and key players underlying Ae. aegypti xenobiotic transport remain largely uncharacterized, but the results of this study are an important step in expanding knowledge of OCT(N)s in mosquitoes and understanding mosquito physiology. Targeting these proteins may offer new avenues for mosquito control. Full article

The soil condition of Norilsk, a large industrial city located in the Arctic zone of Russia, was assessed for the first time using pollution indices calculated based on the gross content of Pb, Zn, Co, Cd, Cu, Ni, Cr, Mn, As, and petroleum products. The Nemerov Pollution Index (NPI) classifies all Norilsk soil samples as polluted. According to the PLI index, 86% of the soil samples were characterized as polluted, and according to the total pollution index (Zc), 56% of the soil samples were classified as moderately hazardous and hazardous polluted. All soil samples had a medium, high, or very high environmental risk. The high level of soil pollution in Norilsk and the crucial role of nonferrous metallurgy as the primary source of these metals are confirmed. Pollutant content in the soil varied in different districts of Norilsk, with Mn and petroleum products being significant. The maximum heavy metal pollution occurred in the soils of the enterprise protection zones and in the soil of the industrial zones. Airborne pollutants from industrial enterprises are the main cause of heavy metal soil pollution in the Norilsk agglomeration. The contribution of other sources of pollution, typical for various functional areas of the city (e.g., motor transport and waste), is not expressed. Simultaneously, the hydrocarbon content is determined by the location of areas near roads, which is typical for districts with a high population and intensive traffic. Using the example of the Central District of Norilsk, the landscaping of the territory was shown to play a role in reducing the total content of heavy metals. Based on the physicochemical properties of Norilsk’s urban soils, the following key measures are proposed to improve soil quality: increasing organic matter content; ensuring a neutral pH and a high cation exchange capacity; and reducing soil density, which will reduce the toxic load on plants and negative impact on human health. Full article

The cholinergic system is one of the most ancient and widespread signaling systems in the body, implicated in a range of pathological conditions—from neurodegenerative disorders to cancer. Given its broad relevance, there is growing interest in characterizing this system across diverse cellular models to enable drug screening, mechanistic studies, and exploration of new therapeutic avenues. In this study, we investigated four cancer cell lines: one of neuroblastoma origin previously used in cholinergic signaling studies (SH-SY5Y), one non-small cell lung adenocarcinoma line (A549), and two small cell lung carcinoma lines (H69 and H82). We assessed the expression and localization of key components of the cholinergic system, along with the cellular capacity for acetylcholine (ACh) synthesis and release. Whole-cell flow cytometry following membrane permeabilization revealed that all cell lines expressed the ACh-synthesizing enzyme choline acetyltransferase (ChAT). HPLC-MS analysis confirmed that ChAT was functionally active, as all cell lines synthesized and released ACh into the conditioned media, suggesting the presence of autocrine and/or paracrine ACh signaling circuits, consistent with previous reports. The cell lines also demonstrated choline uptake, indicative of functional choline and/or organic cation transporters. Additionally, all lines expressed the ACh-degrading enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), as well as the alfa seven (α7) nicotinic and M1 muscarinic ACh receptor subtypes. Notably, flow cytometry of intact SH-SY5Y cells revealed two novel findings: (1) ChAT was localized to the extracellular membrane, a feature not observed in the lung cancer cell lines, and (2) BChE, rather than AChE, was the predominant membrane-bound ACh-degrading enzyme. These results were corroborated by both whole-cell and surface-confocal microscopy. In conclusion, our findings suggest that a functional cholinergic phenotype is a shared feature of several carcinoma cell lines, potentially serving as a survival checkpoint that could be therapeutically explored. The discovery of extracellular membrane-bound ChAT uniquely in neuroblastoma SH-SY5Y cells points to a novel form of in situ ACh signaling that warrants further investigation. Full article

Background: We have previously demonstrated that the function and expression of the Na⁺/taurocholate cotransporting polypeptide (NTCP) and the organic cation transporter 1 (OCT1) are affected by increasing free or unesterified cholesterol in the plasma membrane by an acute incubation with cholesterol for 30 min. In the current study we wanted to extend these findings to a more chronic condition to mimic what would be seen in obese patients. Methods: We incubated HEK293 cells that stably express NTCP or OCT1 for 24 h with 0.05 mM cholesterol and determined their function by measuring uptake of radioactive taurocholate or MPP⁺. Expression at the plasma membrane was quantified with a biotinylation assay combined with Western blots. Results: Incubation with cholesterol increased the cholesterol content of the cells by about 2-fold. Transport mediated by NTCP and OCT1 was decreased. Membrane expression for both transporters showed a slight decrease, and when kinetics were normalized for the membrane expression, the V_max for NTCP-mediated taurocholate uptake slightly decreased, but the V_max and the capacity (V_max/K_m) for OCT1-mediated MPP⁺ uptake increased by 2.5-fold and 3-fold, respectively. Acyl-Coenzyme A acyltransferase inhibitors enhanced the decrease in transport function, potentially due to retention of more free cholesterol in the plasma membrane. Conclusions: Chronic increases in free cholesterol in the plasma membrane can result in increased or decreased transporter function and expression. In the case of OCT1, which is involved in the uptake of the anti-diabetic drug metformin into hepatocytes, the 3-fold increase in transport capacity might affect drug therapy. Full article

Selenium (Se) is a natural detoxifier of the heavy metal mercury (Hg), and the interaction between Se and Hg has been widely investigated. However, the ecological response of Hg to Se in Hg-contaminated farmland requires further study, especially the relationship between Se–Hg interactions and soil abiotic and biological properties. Through a field experiment, the effects of different levels of exogenous Se (0, 0.50, 0.75, 1.00, and 2.00 mg kg⁻¹) on Hg and Se transport in maize, soil properties, enzyme activities, and the microbial community in Hg-contaminated farmland were systematically studied. The Se treatments significantly reduced the Hg concentration in maize roots, stems, leaves, and grains and significantly increased the Se concentration in maize tissues. Except for the 0.75 mg kg⁻¹ Se treatment which significantly increased electrical conductivity compared to the control, other Se treatments had non-significant effect on soil physicochemical properties (pH, conductivity, organic matter content, and cation exchange capacity) and oxidoreductase activities (catalase, peroxidase, and ascorbate peroxide). The activities of soil invertase, urease, and alkaline phosphatase increased significantly after Se application, and the highest enzyme activities were observed with a 0.50 mg kg⁻¹ Se treatment. The bacteria and fungi with the highest relative abundance in this study were Proteobacteria (>30.5%) and Ascomycota (>73.4%). The results of a redundancy analysis and predictions of the microbial community showed that there was a significant correlation between the soil nutrient cycle enzyme activity, microbial community composition, and microbial community function. Overall, exogenous Se application was found to be a viable strategy for mitigating the impact of Hg stress on ecosystems. Furthermore, the results provide new insights into the potential for the large-scale application of Se in the remediation of Hg-contaminated farmland. Full article

The influence of petroleum hydrocarbons (PHCs) on the transport and transformation of heavy metals may limit bioremediation efficiency. The mechanisms by which PHC degradation intermediates control heavy metal distribution in calcareous soils from karst areas require further exploration. This study systematically investigated how compositional changes in diesel fuel during aging regulated the fate of Cd and Pb in calcareous soils. The results demonstrated that the low-molecular-weight fractions of diesel fuel (C₁₀−C₁₆) were preferentially degraded. This degradation process altered zeta potential, cation exchange capacity (CEC), and pH, thereby promoting Cd stabilization through electrostatic attraction and speciation transformation. Particularly, reducible Cd content showed a strong positive correlation with C₁₆ content (r = 0.88, p < 0.05). Furthermore, the degradation of C₁₀−C₁₆ fractions caused Pb transformation from residual to bioavailable fractions by stimulating microbial activity. Residual Pb content was positively correlated with C₁₀−C₁₆ fractions (r = 0.55, p < 0.05). Notably, dissolved organic matter (DOM) and CaCO₃ content in calcareous soils enhanced Cd and Pb adsorption, thereby weakening the interactions between these metals and C₁₀−C₁₆ fractions. Consequently, multiple linear regression (MLR) models relying exclusively on C₁₀−C₁₆ degradation parameters showed poor fitting coefficients for Cd/Pb mobility. The present work provides scientific guidance for heavy metal bioremediation in calcareous soils. Full article

Periodontal regeneration remains challenging due to individual variability, especially in treatments involving bioactive factors such as metformin. This study aimed to investigate the role of organic cation transporters (OCTs) in metformin-induced periodontal regeneration. The expression and function of OCTs in human periodontal ligament stem cells (hPDLSCs) were assessed, and OCT-mediated metformin uptake was quantified by high-performance liquid chromatography (HPLC). Osteogenic and cementogenic differentiation markers were analyzed in vitro, and periodontal regeneration was evaluated using a rat periodontal defect model. OCTs were differentially expressed and functional in hPDLSCs. Both the OCT1 inhibitor cimetidine and OCT1 knockdown significantly reduced intracellular metformin accumulation to 50–60% and 20–30% of control levels, respectively (p < 0.01). Cimetidine diminished the osteogenic and cementogenic effects of metformin by approximately 31–48% and 32–40%, respectively (p < 0.01). In vivo, oral administration of cimetidine decreased bone regeneration by 25% and cementum regeneration by 36% compared with controls receiving GelMA/hPDLSCs/metformin (p < 0.01). This study demonstrates that OCTs regulate metformin uptake in hPDLSCs, and that inhibition of OCT1 by cimetidine significantly reduces the osteogenic and cementogenic efficacy of metformin, providing the first evidence of drug interactions affecting periodontal regeneration mediated by OCT transport in rats. Full article

The advent of the lithium-ion batteries (LIBs) has transformed the energy storage field, leading to significant advances in electronics and electric vehicles, which continuously demand more and more performant devices. However, commercial LIB systems are still far from satisfying applications operating in arduous conditions, such as temperatures exceeding 100 °C. For instance, safety issues, materials degradation, and toxic stem development, related to volatile, flammable organic electrolytes, and thermally unstable salts (LiPF₆), limit the operative temperature of conventional lithium-ion batteries, which only occasionally can exceed 50–60 °C. To overcome this highly challenging drawback, the present study proposes advanced electrolyte technologies based on innovative, safer fluids such as ionic liquids (ILs). Among the IL families, we have selected ionic liquids based on tetrabutylphosphonium and 1-ethyl-3-methyl-imidazolium cations, coupled with per(fluoroalkylsulfonyl)imide anions, for standing out because of their remarkable thermal robustness. The thermal behaviour as well as the ion transport properties and electrochemical stability were investigated even in the presence of the lithium bis(trifluoromethylsulfonyl)imide salt. Conductivity measurements revealed very interesting ion transport properties already at 50 °C, with ion conduction values ranging from 10⁻³ and 10⁻² S cm⁻¹ levelled at 100 °C. Thermal robustness exceeding 150 °C was detected, in combination with anodic stability above 4.5 V at 100 °C. Preliminary cycling tests run on Li/LiFePO₄ cells at 100 °C revealed promising performance, i.e., more than 94% of the theoretical capacity was delivered at a current rate of 0.5C. The obtained results make these innovative electrolyte formulations very promising candidates for high-temperature LIB applications and advanced energy storage systems. Full article