Search Results (177)

Microplastics (MPs) and their chemical leachates are increasingly detected in landfill leachate, raising concerns about impacts on biological nitrogen removal. This study examined the effects of low-density polyethylene (LDPE) and polypropylene (PP) MPs on anaerobic ammonium oxidation (anammox) performance using suspended, attached, and granular biomass. The results showed that exposure to LDPE and PP MPs did not significantly inhibit specific anammox activity (SAA) across all anammox biomass types. However, the leachates of LDPE and PP MPs under relevant EU migration testing guidelines could cause transient inhibition. Non-targeted GC-MS analysis identified 31 and 37 leachable compounds from LDPE and PP, including the toxic plasticizer dibutyl phthalate (DBP). DBP caused concentration-dependent but transient inhibition of nitrogen removal in granular biomass, peaking at 29.4% after 5 h at 100 mg/L, with full recovery within 24 h. Higher DBP retention was observed in granular and attached growth biomass compared to suspended growth biomass. Crucially, complex biomass structures buffer these effects, emphasizing the need to assess both physical and chemical MP aspects in wastewater systems. Consequently, attached growth and granular systems are recommended over suspended growth configurations for leachate treatment, owing to their superior resilience to toxic shock and enhanced retention capabilities. Full article

To address the problem of serious gas channeling during CO₂ flooding in low-permeability reservoirs, which leads to poor oil recovery, this study developed a CO₂-resistant gel using a novel CO₂-responsive polymer (ADA) for gas channel control. The ADA polymer was synthesized via free-radical copolymerization of acrylamide (AM), dimethylaminopropyl methacrylamide (DMAPMA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), which introduced protonatable tertiary-amine groups and sulfonate moieties into the polymer backbone. Comprehensive characterizations confirmed the designed structure and adequate thermal stability of the ADA polymer. Rheological tests demonstrated that the ADA polymer solution exhibits significant CO₂-triggered viscosity enhancement and excellent shear resistance. When crosslinked with phenolic resin, the resulting ADA gel showed outstanding CO₂ tolerance under simulated reservoir conditions (110 °C, 10 MPa). After 600 s of CO₂ exposure, the ADA gel retained over 99% of its initial viscosity, whereas a conventional HPAM-based industrial gel degraded to 61% of its original viscosity. The CO₂-resistance mechanism involves protonation of tertiary amines to form quaternary ammonium salts, which electrostatically interact with sulfonate groups, creating a reinforced dual-crosslinked network that effectively protects the gel from H⁺ ion attack. Core flooding experiments confirmed its ability to enhance oil recovery by plugging high-permeability channels and diverting flow, achieving a final recovery of up to 48.5% in heterogeneous cores. This work provides a novel gel system for improving sweep efficiency and storage security during CO₂ flooding in low-permeability reservoirs. Full article

The development of China’s manganese (Mn) industries has caused severe water and soil pollution, threatening ecological and human health. Microbes are usually regarded as an important indicator of environmental pollution assessment. However, the current understanding of microbial community characteristics and their formation mechanisms in Mn production areas remains limited. In order to address this, soil properties and microbial structural characteristics across different functional zones in a typical Mn electrolysis plant in China’s “Manganese Triangle” were investigated via metagenomic sequencing. Results showed soil Mn levels significantly exceeded background values, indicating high environmental risk. Acidobacteria and Proteobacteria were dominant phyla. Microbial abundance was lowest in the adjacent natural reservoir, whereas diversity was highest in the sewage treatment plant. Correlation analyses identified Mn, nitrate nitrogen, ammonium nitrogen, pH, and moisture as key environmental drivers, with Mn being the primary one. Metagenomic analysis revealed abundant Mn resistance genes, enabling microbial survival under high Mn stress. This study demonstrated that excessive Mn exposure enriched Mn-resistant genes, thereby shaping unique microbial communities dominated by Mn-resistant bacteria. These findings clarified the structural characteristics and adaptive mechanisms of soil microbial communities in Mn-contaminated areas, providing a theoretical basis for ecological risk management and bioremediation. Full article

Fluoride contamination in groundwater is a pressing environmental and public health issue, with chronic exposure linked to skeletal and dental fluorosis. Here, we report the synthesis of magnesium oxide nanoparticles via a controlled co-precipitation method employing dimethylformamide (DMF) as solvent and either ammonium hydroxide (MgO-1) or ammonium carbonate (MgO-2) as precipitating agents. The resulting materials were comprehensively characterized using thermogravimetric analysis (TGA/DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). Additionally, BET surface area and porosity analyses revealed mesoporous structures, with MgO-1 showing a slightly higher surface area (14.12 m² g⁻¹) than MgO-2 (13.87 m² g⁻¹). Both MgO-1 and MgO-2 exhibited high crystallinity, nanoscale particle sizes (81.6 nm and 128.1 nm, respectively), and distinct morphological features. Batch adsorption studies revealed maximum fluoride uptake capacities of 117.6 mg/g (MgO-1) and 94.5 mg/g (MgO-2) at neutral pH, with MgO-1 exhibiting superior performance due to its smaller particle size and higher specific surface area. Fluoride removal remained above 98% between pH 3–9, confirming stability across a wide pH range, with a minor decline at pH 11 due to OH⁻ competition. Adsorption equilibrium data were best described by the Temkin isotherm model, suggesting heterogeneous surface interactions and an exothermic process, while kinetic analyses indicated pseudo-second-order behavior for MgO-1 and pseudo-first-order for MgO-2. Both materials maintained high fluoride selectivity in the presence of competing anions and successfully reduced fluoride in tap water from 2.11 mg/L to below the WHO limits without altering water hardness. These findings underscore the potential of engineered MgO nanomaterials as efficient, selective, and sustainable adsorbents for water defluoridation, offering a promising pathway toward scalable remediation technologies in fluoride-affected regions. Full article

Toxicant-associated steatohepatitis (TASH) is caused by environmental toxicants rather than metabolic factors; however, its pathogenic mechanisms remain poorly understood. Polychlorinated biphenyl 138 (PCB138), a persistent lipophilic contaminant that bioaccumulates in adipose tissue, may promote TASH through unclear mechanisms. In this study, we investigated whether PCB138 induces liver injury via hepatic iron dysregulation and adipose-liver inflammatory signaling. Male C57BL/6 mice received intraperitoneal PCB138 (1, 5, 10, or 50 mg/kg, four injections over six weeks). HepG2 hepatocytes were treated with PCB138 with or without ferric ammonium citrate (FAC), and PCB138-exposed 3T3-L1 adipocytes were co-cultured with HepG2 cells using a Transwell system. PCB138 dose-dependently increased serum transaminase and hepatic non-heme iron levels, with Hamp upregulation, macrophage infiltration, and fibrosis. In HepG2 cells, PCB138 synergized with FAC to elevate intracellular Fe²⁺, induced Hamp, suppressed Slc40a1, and upregulated inflammatory/profibrotic genes. In Transwell co-cultures, TNF-α, IL-6, and IL-1β from PCB138-exposed adipocytes amplified hepatic iron dysregulation and fibrotic responses. These findings demonstrated that PCB138 induced TASH through hepatic iron dysregulation and adipose-derived inflammatory signaling, independent of steatosis. These results highlighted the iron–adipose axis as a novel mechanistic link between PCB138 exposure and liver injury, offering potential therapeutic targets. Full article

Objectives: This study utilized IPEC-J2, a neonatal pig jejunum-derived cell line, to assess how iron deficiency (ID) and excess (IE) alter enterocyte metabolism and the transcription of inflammatory markers. Methods: Cells were treated with deferiprone (DFP) or ferric ammonium citrate (FAC) to induce ID or IE, respectively. The study evaluated: (1) transcriptional changes in iron-regulatory genes over 96 h under ID or IE; (2) the interaction between iron imbalance and lipopolysaccharide (LPS) exposure on mRNA expression of inflammation markers and iron transporters; and (3) cellular metabolic responses to ID, IE, and iron repletion using untargeted metabolomics. Results: ID triggered dynamic transcriptional changes in iron regulatory genes and suppressed cellular proliferation via impaired DNA replication. IE resulted in a persistent reduction in TFRC expression. LPS increased CYBRD1 (p < 0.001) and IL8 (p = 0.004) and tended to elevate TLR4 and TNF expression (p ≤ 0.07), while iron deficiency upregulated IL8 expression (p < 0.001). ID disrupted the TCA cycle, reduced glucuronic acid synthesis, and elevated glycolysis for energy production, whereas IE increased cholesterol biosynthesis and decreased alpha-tocopherol levels. Repletion of iron partially reversed ID-induced metabolic changes. Conclusions: ID impaired enterocyte proliferation and profoundly disrupted cellular metabolism, whereas IE enhanced cholesterol synthesis and depleted alpha-tocopherol levels. Restoration of cellular metabolism following iron repletion was observed, highlighting the resilience of enterocytes. Full article

A major objective in recent years has been the use of membrane sensors for the purpose of monitoring and recognizing environmental pollutants in pharmaceuticals. Ketoprofen (KTP) is likely to be found in the environment, particularly in surface water bodies like rivers, because of its extensive use in medicine. The photodegradability of KTP and the prolonged exposure of river water to sunlight may facilitate its photodegradation. To measure KTP along with its main photo-degradation products, three membrane electrodes were fabricated using different plasticizers. Dioctyl phthalate (DOP), dibutyl sebacate (DBS), and o-nitrophenyloctyl ether (o-NPOE) membrane electrodes were constructed for the selective analysis of the investigated medication. The fabricated sensors were prepared using tetraoctyl ammonium chloride as an ion-pairing agent. A linear range of 1 × 10⁻⁵ M to 1 × 10⁻¹ M was shown by the electrodes. The slopes (in mV/decade) for the DOP, DBS, and o-NPOE membranes were −58.80 ± 0.90, −57.90 ± 0.80, and −56.80 ± 1.10, respectively. All test parameters were refined to enhance electrochemical performance. The synthesized membranes were successfully utilized to accurately measure KTP amidst its primary photodegradants. The fabricated sensors were effectively utilized to measure KTP in river water samples without requiring pre-treatment processes. Full article

Particulate matter with a diameter less than 2.5 µm (PM_2.5) and its chemical constituents—including ammonium (NH₄⁺), sulfate (SO₄²⁻), nitrate (NO₃⁻), organic carbon (OC), soil dust, and black carbon (BC)—have been increasingly recognized for their potential impact on fetal neurodevelopment. This systematic review aimed to synthesize current evidence on the relationship between prenatal exposure to PM_2.5 and its chemical components and neurodevelopmental outcomes in neonates, focusing on diagnoses such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). Following PRISMA 2020 guidelines, a comprehensive literature search was conducted on PubMed and Embase databases from April to July 2025. Twenty-five studies meeting inclusion criteria were analyzed, of which sixteen addressed PM_2.5 exposure generally, and nine assessed specific chemical constituents. The findings indicate that increased exposure to PM_2.5, particularly during the third trimester, is associated with a higher risk of ASD. Additionally, prenatal exposure may adversely affect early neurodevelopmental domains including motor skills, problem-solving, and social interactions. Certain PM_2.5 components, notably sulfate ions (SO₄²⁻), were identified as important contributors to neurological health outcomes. These results underscore the importance of reducing prenatal exposure to PM_2.5 and its harmful constituents to protect neurodevelopment. Full article

Quaternary ammonium compounds (QACs) are a class of chemicals used for their antimicrobial, surfactant, and antistatic properties. QACs are present in many consumer products, and people are regularly exposed to them. We have previously shown reproductive toxicity in mice exposed to the disinfectants alkyl dimethyl benzyl ammonium chloride (ADBAC) and dodecyl dimethyl ammonium chloride (DDAC). To assess the long-term reproductive impacts, a generational reproductive study was conducted. Sperm parameters were determined by CASA and epigenetic enzyme mRNA expression was determined by pathway-focused RT-PCR. Mice ambiently exposed to ADBAC+DDAC exhibited decreases in reproductive indices that persisted through the F1 generation. Male mice (F0) dosed with 120 mg/kg/day of ADBAC+DDAC exhibited decreased sperm concentration and motility that persisted through the F1 generation. Changes in the mRNA expression of chromatin-modifying enzymes in the testes were seen. Two histone acetyltransferases (Hat1 and Kat2b) were upregulated, and one lysine-specific demethylase (Kdm6b) was downregulated in the F0 generation. The DNA methyltransferase Dnmt1 was downregulated in F1 males. These changes in chromatin-modifying enzymes are known to decrease fertility and could be a mechanism for ADBAC+DDAC reproductive toxicity. In all experiments, the F2 generation was similar to the controls, showing multi-generational but not trans-generational epigenetic inheritance. Full article

Glufosinate-ammonium (GLA) is a broad-spectrum herbicide widely used for weed control. However, its potential toxic effects on non-target aquatic organisms, especially in freshwater ecosystems, are of growing concern. This study investigates the toxic effects of GLA on Biomphalaria glabrata, a freshwater snail highly sensitive to environmental pollutants and commonly used as a model organism in toxicological studies. Acute toxicity tests revealed that the 96-h LC50 of GLA for adult snails was 3.77 mg/L, indicating moderate toxicity, while the LC50 for embryos was 0.01576 mg/L, indicating extremely high toxicity. Chronic exposure experiments further showed that at high concentrations (0.5 mg/L), the shell diameter and body weight of the snails not only failed to increase but also decreased, and they ceased to lay eggs. Moreover, their hepatopancreas and gonads suffered significant damage. Even at an environmentally relevant concentration of 0.05 mg/L, the body length, body weight, and reproductive capacity of the snails were inhibited, and damage to the hepatopancreas and gonads was observed. These findings provide important data for assessing the potential risks of GLA to aquatic ecosystems and offer a scientific basis for formulating environmental protection policies and optimizing herbicide usage standards. Full article

Background: The FDA-cleared antimicrobial quaternary ammonium silane K21 is recognized for its antimicrobial properties. This study explored potential applications of the K21 molecule in human health protection, disease prevention, and treatment using the zebrafish model. Method: A multi-dimensional approach was utilized to assess the toxicity, tolerance, and optimal dosage of K21 through serial dilutions at various concentrations. Acute and chronic exposure studies were performed at different developmental stages (embryonic, larval, juvenile, and adult) to evaluate its efficacy and toxicity in wild-type (WT), Casper (transparent skin mutant), and transgenic zebrafish lines. Results: Significant weight gain was observed in the F1 generation following K21 treatment, a trend that continued into the F2 and F3 generations. The effects of K21 on lipopolysaccharide-induced inflammation were also examined in Casper NFkB:GFP transgenic lines. Treatment with K21 reduced inflammation, indicating anti-inflammatory properties. Improved hatching rates, accelerated larval development, an increased adult mass, and modest reductions in embryonic motility (less than 20%) suggested positive developmental influences. Single-cell RNA sequencing further validated the biological impacts of K21, revealing the potential activation of a novel pathway that accelerates zebrafish growth. Summary and Conclusions: These findings position K21 as a promising candidate for biomedical applications and aquaculture, warranting further investigation into its underlying molecular mechanisms. Our additional study on the effect of K21 on the artemia (brine shrimp) hatching process provide strong evidence of better hatching ratio of 90% for brine shrimp in the group with K21 drug treatment as compared to 70% in the group without the K21 drug at 24 h of treatment; the K21 drug helps the early hatching process, as observed the 90% hatching rate in 20 h K21 treatment group hatching while in the group without K21, only 40% of brine shrimps hatched. Full article

Background/Objectives: Desiccation profoundly influences the distribution and abundance of intertidal seaweeds, necessitating robust molecular adaptations. Sargassum muticum is a brown seaweed inhabiting intertidal rocky substrates. During low tides, this species undergoes periodic aerial exposure. Such environmental conditions necessitate robust physiological mechanisms to mitigate desiccation stress. Yet, the molecular basis of this adaptation remains poorly understood. Methods: To investigate desiccation-responsive genes and elucidate the underlying mechanisms of adaptation, we exposed S. muticum to 6 h of controlled desiccation stress in sterilized ceramic trays, simulating natural tidal conditions, and performed comparative transcriptome analysis using RNA-seq on the Illumina NovaSeq 6000 platform. Results: High-quality sequencing identified 66,192 unigenes, with 1990 differentially expressed genes (1399 upregulated and 591 downregulated). These differentially expressed genes (DEGs) were categorized into regulatory genes—including mitogen-activated protein kinase (MAPK), calmodulin, elongation factor, and serine/threonine-protein kinase—and functional genes, such as heat shock protein family members (HSP20, HSP40, and HSP70), tubulin (TUBA and TUBB), and endoplasmic reticulum homeostasis-related genes (protein disulfide-isomerase A6, calreticulin, and calnexin). Gene Ontology (GO) enrichment highlighted upregulated DEGs in metabolic processes like glutathione metabolism, critical for oxidative stress mitigation, while downregulated genes were linked to transport functions, such as ammonium transport, suggesting reduced nutrient uptake during dehydration. KEGG pathway analysis revealed significant enrichment in “protein processing in endoplasmic reticulum” and “MAPK signaling pathway-plant”, implicating endoplasmic reticulum stress response and conserved signaling cascades in desiccation adaptation. Validation via qRT-PCR confirmed consistent expression trends for key genes, reinforcing the reliability of transcriptomic data. Conclusions: These findings suggest that S. muticum undergoes extensive biological adjustments to mitigate desiccation stress, highlighting candidate pathways for future investigations into recovery and tolerance mechanisms. Full article

Background and Objectives: Successful endodontic treatment requires thorough disinfection and removal of the smear layer to prevent reinfection. However, conventional irrigants like sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) can compromise dentin integrity. This study assessed the efficacy of the Synergistic Microbicidal and Ablative Root canal Technique (SMART), which integrates AromaRoot, a biocompatible irrigation solution based on quaternary ammonium compounds, with 980 nm diode laser activation, to enhance bacterial reduction and smear layer removal. Materials and Methods: Sixty extracted single-rooted human teeth were inoculated with Enterococcus faecalis and divided into four treatment groups using NaOCl, AromaRoot, and 980 nm laser, either alone or in combination. Bacterial counts were measured as colony-forming units per milliliter (CFU/mL). For smear layer analysis, 56 extracted teeth were prepared and irrigated using EDTA, AromaRoot, and laser activation, followed by scanning electron microscopy to evaluate dentinal tubule exposure. Data were analyzed using Kruskal–Wallis and ANOVA. Results: The combination of AromaRoot, NaOCl, and laser activation achieved a 99.00% bacterial reduction (from 8082 to 60 CFU/mL, p < 0.001), outperforming NaOCl alone (98.34%, 131 CFU/mL). For smear layer removal, AromaRoot with laser achieved 78.5% open dentinal tubules in the apical third, significantly higher than EDTA alone (64.5%, p < 0.05), though EDTA remained superior in the coronal third (89.0% vs. 81.0%, p > 0.05). Conclusions: The SMART technique significantly improves both disinfection and smear layer removal in root canal therapy, particularly in the apical region. These findings suggest that AromaRoot, especially when laser-activated, may serve as a safe and effective alternative to conventional irrigants, warranting further clinical evaluation. Full article

Linear anionic surfactants (LAS) pose significant stress to microbial denitrification in wastewater treatment. This study investigated the performance and adaptation mechanisms of heterotrophic nitrification-aerobic denitrification (HN-AD) microbial consortia under LAS exposure after short-term (SCM, 2 months) and long-term (LCM, 6 months) acclimation. Results showed a dose-dependent inhibition of total nitrogen (TN) removal, with LCM achieving 97.40% TN removal under 300 mg/L LAS, which was 16.89% higher than SCM. Biochemical assays indicated that LCM exhibited lower reactive oxygen species (ROS) levels, a higher ATP content, and reduced LDH release, suggesting enhanced oxidative stress resistance and membrane stability. EPS secretion also increased in LCM, contributing to environmental tolerance. Metagenomic analysis revealed that long-term acclimation enriched key genera including Pseudomonas, Aeromonas, and Stutzerimonas, which maintained higher expression of denitrification (e.g., nosZ, nirS) and ammonium assimilation genes (glnA, gltB). Although high LAS concentrations reduced overall community diversity and led to convergence between SCM and LCM structures, LCM retained greater functional capacity and stress resistance. These findings underscore the importance of acclimation in sustaining denitrification performance under surfactant pressure and offer valuable insights for engineering robust microbial consortia in complex wastewater environments. Full article

Excessive ammonia accumulation poses a significant threat to aquatic species. Potamocorbula ustulata, known for its burrowing behavior and high population density, may experience elevated ammonia levels in its environment. However, its ammonia stress response mechanisms remain unclear. This study investigates the physiological and molecular responses of P. ustulata to acute ammonia exposure. Antioxidant enzyme activity was significantly altered in the gills and hepatopancreas, with GS, GDH, and ARG levels markedly increasing in the hepatopancreas. Transcriptome analysis revealed that after 24 h of exposure, differentially expressed genes (DEGs) were enriched in apoptosis and inflammation-related pathways (MAPK, NF-kB, NOD-like receptor signaling). By 96 h, DEGs in the gills were associated with nitrogen metabolism and transport, while those in the hepatopancreas were linked to oxidative phosphorylation and amino acid metabolism. Key ammonia transport and excretion genes, including V-type H⁺-ATPase, Ammonium transporter Rh, and Na⁺/K⁺-ATPase, were significantly upregulated in the gills, while glutamine synthetase and glutamate dehydrogenase were upregulated in the hepatopancreas (p < 0.05). These findings suggest that ammonia stress disrupts antioxidant defense, triggers inflammation and apoptosis, and enhances ammonia tolerance through excretion, glutamine conversion, and urea synthesis. This study provides insights into the molecular mechanisms underlying ammonia tolerance in bivalves. Full article