RESUMEN
Nitrate (NO3-) is a widespread pollutant in high-salt wastewater and causes serious harm to human health. Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method, the development of low-cost electro-catalysts is still challenging. In this work, a phosphate modified iron (P-Fe) cathode was prepared for electrochemical removal of nitrate in high-salt wastewater. The phosphate modification greatly improved the activity of iron, and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode. Further experiments and density functional theory (DFT) calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO3- removal. The nitrate was firstly electrochemically reduced to ammonium, and then reacted with the anodic generated hypochlorite to N2. In this study, a strategy was developed to improve the activity and stability of metal electrode for NO3- removal, which opened up a new field for the efficient reduction of NO3- removal by metal electrode materials.
Asunto(s)
Electrodos , Hierro , Nitratos , Fosfatos , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua , Aguas Residuales/química , Nitratos/química , Hierro/química , Fosfatos/química , Contaminantes Químicos del Agua/química , Eliminación de Residuos Líquidos/métodos , Técnicas Electroquímicas/métodosRESUMEN
Nano zero-valent iron (nZVI) is a promising phosphate adsorbent for advanced phosphate removal. However, the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance, accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate. In this study, we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites. As expected, the stronger anti-passivation ability of oxalate modified nZVI (OX-nZVI) strongly favored its phosphate adsorption. Interestingly, the oxalate modification endowed the surface Fe(III) sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites, by in situ forming a Fe(III)-phosphate-oxalate ternary complex, therefore enabling an advanced phosphate removal process. At an initial phosphate concentration of 1.00 mg P/L, pH of 6.0 and a dosage of 0.3 g/L of adsorbents, OX-nZVI exhibited faster phosphate removal rate (0.11 g/mg/min) and lower residual phosphate level (0.02 mg P/L) than nZVI (0.055 g/mg/min and 0.19 mg P/L). This study sheds light on the importance of site manipulation in the development of high-performance adsorbents, and offers a facile surface modification strategy to prepare superior iron-based materials for advanced phosphate removal.
Asunto(s)
Hierro , Oxalatos , Fosfatos , Contaminantes Químicos del Agua , Fosfatos/química , Adsorción , Hierro/química , Contaminantes Químicos del Agua/química , Oxalatos/química , Purificación del Agua/métodos , Modelos QuímicosRESUMEN
Sphingolipids are the most diverse class of lipids due to the numerous variations in their structural components. This diversity is also reflected in their extremely different functions. Sphingolipids are not only constituents of cell membranes but have emerged as key signaling molecules involved in a variety of cellular functions, such as cell growth and differentiation, proliferation and apoptotic cell death. Lipidomic analyses in clinical research have identified pathways and products of sphingolipid metabolism that are altered in several human pathologies. In this article, we describe how to properly design a lipidomic experiment in clinical research, how to handle plasma and serum samples for this purpose, and how to measure sphingolipids using liquid chromatography-mass spectrometry.
Asunto(s)
Lipidómica , Esfingolípidos , Esfingolípidos/metabolismo , Esfingolípidos/sangre , Humanos , Lipidómica/métodos , Cromatografía Liquida/métodos , Espectrometría de Masas/métodosRESUMEN
BACKGROUND: Powdery mildew is a disease with one of the most substantial impacts on cucumber production globally. The most efficient approach for controlling powdery mildew is the development of genetic resistance; however, few genes associated with inherent variations in cucumber powdery mildew resistance have been identified as of yet. RESULTS: In this study, we re-sequence 299 cucumber accessions, which are divided into four geographical groups. A genome-wide association study identifies 50 sites significantly associated with natural variations in powdery mildew resistance. Linkage disequilibrium analysis further divides these 50 sites into 32 linkage disequilibrium blocks containing 41 putative genes. Virus-induced gene silencing and gene expression analysis implicate CsGy5G015960, which encodes a phosphate transporter, as the candidate gene regulating powdery mildew resistance. On the basis of the resequencing data, we generate five CsGy5G015960 haplotypes, identifying Hap.1 as the haplotype most likely associated with powdery mildew resistance. In addition, we determine that a 29-bp InDel in the 3' untranslated region of CsGy5G015960 is responsible for mRNA stability. Overexpression of CsGy5G015960Hap.1 in the susceptible line enhances powdery mildew resistance and phosphorus accumulation. Further comparative RNA-seq analysis demonstrates that CsGy5G015960Hap.1 may regulate cucumber powdery mildew resistance by maintaining a higher H2O2 level through the depletion of multiple class III peroxidases. CONCLUSIONS: Here we identify a candidate powdery mildew-resistant gene in cucumber using GWAS. The identified gene may be a promising target for molecular breeding and genetic engineering in cucumber to enhance powdery mildew resistance.
Asunto(s)
Cucumis sativus , Resistencia a la Enfermedad , Estudio de Asociación del Genoma Completo , Desequilibrio de Ligamiento , Enfermedades de las Plantas , Cucumis sativus/genética , Cucumis sativus/microbiología , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Ascomicetos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , HaplotiposRESUMEN
OBJECTIVE: In this study we have focused on biocompatibility and osteoinductive capacity analysis of self-manufactured single-phase (HAP) and two-phase (HAP and ß-ТСР) bioactive ceramics with various chemical modifications (Fig. 1). RESULTS: We demonstrate a reduction in solubility for all analyzed composite after the treatment with H2O and H2O2, accompanied by an enhancement in adsorption activity. This modification also resulted in an increase in micro- and macroporosity, along with a rise in the open porosity. Adipose-derived mesenchymal stromal cells demonstrated excellent cell adhesion and survival when cultured with these ceramics. Calcium phosphate ceramics (H-500, HT-500, and HT-1 series) stimulated alkaline phosphatase expression, promoted calcium deposition, and enhanced osteopontin expression in ADSCs, independently inducing osteogenesis without additional osteogenic stimuli. These findings underscore the promising potential of HAP-based bioceramics for bone regeneration/reconstruction.
Asunto(s)
Materiales Biocompatibles , Fosfatos de Calcio , Diferenciación Celular , Cerámica , Células Madre Mesenquimatosas , Osteogénesis , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Cerámica/química , Cerámica/farmacología , Osteogénesis/efectos de los fármacos , Fosfatos de Calcio/farmacología , Fosfatos de Calcio/química , Diferenciación Celular/efectos de los fármacos , Humanos , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/química , Adhesión Celular/efectos de los fármacos , Ensayo de Materiales , Supervivencia Celular/efectos de los fármacos , Fosfatasa Alcalina/metabolismo , Osteopontina/metabolismo , Células Cultivadas , PorosidadRESUMEN
For decades, calcium phosphate (CaP)-based ceramics have been used for coating of bone and joint substitutes after arthroplasty due to their biocompatible properties. Infections following orthopedic replacement occur in 1%-5% of cases, causing serious complications. Biofilm formation either on the biomaterial's surface or on patient's tissues greatly enhances the resistance against antibiotic treatments and can induce a chronic infection, emphasizing the need for novel antimicrobial delivery systems. In this study, we established a protocol enabling bacteriophage loading during the synthesis of a CaP-based powder. The resulting biomaterial proved to be noncytotoxic against human osteoblastic cells and able to significantly inhibit 24-h matured S. aureus biofilm cultures or even completely eradicate it after 5 days of contact. Additional S. aureus biofilm assays with a freeze-dried material using two different excipients showed that sucrose had a protective role against Remus bacteriophage treatment of S. aureus biofilms, whereas lactose-freeze-dried powder maintained the antibiofilm activity.
RESUMEN
The sustainable development of lithium iron phosphate (LFP) batteries calls for efficient recycling technologies for spent LFP (SLFP). Even for the advanced direct material regeneration (DMR) method, multiple steps including separation, regeneration, and electrode refabrication processes are still needed. To circumvent these intricacies, new regeneration methods that allow direct electrode reuse (DER) by rejuvenating SLFP electrodes without damaging its structure are desired. Here, a 0.1 M lithium triethyl borohydride/tetrahydrofuran solution, which has the proper reductive capability to reduce Fe3+ in SLFP to Fe2+ without alloying with the aluminum current collector, is selected as the lithiation/regeneration reagent to restock the Li loss and regenerate SLFP electrodes. By soaking the SLFP electrodes in the lithiation solution, we successfully rejuvenated the crystal structure and electrochemical activity of SLFP electrodes with structural integrity within only 6 minutes at room temperature. When being directly reused, the regenerated LFP electrodes deliver a high specific capacity of 162.6 mAh g-1 even after being exposed to air for 3 months. The DER strategy presents significant economic and environmental benefits compared with the DMR method. This research provides a timely and innovative solution for recycling spent blade batteries using large-sized LFP electrodes, boosting the closed-loop development of LFP batteries.
RESUMEN
The PHOSPHATE STARVATION RESPONSE REGULATOR (PHR) plays a crucial regulatory role in plants during the process of responding to phosphate starvation. In this study, we combined reverse genetics and biotechnology to investigate the function of ZmPHR1 and ZmPHR2, including proteins containing the Myb_DNA_banding and Myb_CC-LHEQLE structural domains, in maize seedlings. Phylogenetic analysis revealed that ZmPHR1 and ZmPHR2 have high homology with AtPHR1 and OsPHR2, and share the characteristic features of nuclear localisation and transcriptional self-activation. Real-time quantitative PCR analysis showed that low phosphate (Pi) stress significantly induced the expression of ZmPHR1 and ZmPHR2 in maize seedling stage, and candidate gene association analysis further revealed the close association of these two genes with root traits under Pi stress conditions. Transgenic plants overexpressing ZmPHR1 and ZmPHR2 in Arabidopsis show a significant increase in lateral root number, fresh weight and total phosphorus accumulation under low-Pi stress. Besides, CHIP-PCR experiments identified target genes involved in hormone regulation, metal ion transport and homeostasis, phosphatase encoding, and photosynthesis, providing new insights into the biological functions of ZmPHR1 and ZmPHR2. Furthermore, our study showed that ZmPHR1 interacts with six SPX domain-only proteins (ZmSPXs) in maize, while ZmPHR2 interacts with five of these proteins. ZmPHR1 and ZmPHR2 expression was repressed in low Pi conditions, but was up-regulated in ZmSPX1 knockout material, according to our study of transgenic seedlings overexpressing ZmSPX1 in maize. We identified downstream target genes involved in the phosphorus signaling pathway, which are mainly involved in plant-pathogen interactions, ascorbic acid and arabinose metabolism, and ABC transporter proteins, by RNA-seq analysis of transgenic seedlings grown under low Pi stress for 7 days. Collectively, these results provide important clues to elucidate the role and functional significance of ZmPHR1 and ZmPHR2 under low Pi stress and also provide insights into understand the molecular mechanism of phosphorus homeostasis in maize. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01508-2.
RESUMEN
Histidine dipeptides (HDs) are synthesized in brain oligodendrocytes by carnosine synthase (carns1), but their role is unknown. Using metabolomics and in vivo experiments with both constitutive and oligodendrocyte-selective carns1-KO mouse models, we found that HDs are critical for oligodendrocyte survival and protect against oxidative stress. Carns1-KO mouse models had lower numbers of mature oligodendrocytes, increased lipid peroxidation, and behavioral changes. Cuprizone administration, which increases reactive oxygen species in vivo, resulted in higher oligodendrocyte death, demyelination, axonal alterations, and oxidative damage in the corpus callosum of carns1-KO mice. Gliosis and oxidative damage by cuprizone were prevented by pretreatment with the antioxidant N-acetylcysteine. NADPH levels were increased threefold in the brains of carns1-KO mice as an antioxidant response to oxidative stress through acceleration of the pentose phosphate pathway (PPP). This was due to overexpression of glucose-6-phosphate dehydrogenase, the rate-limiting enzyme of the PPP. Likewise, expression of NAD kinase, the biosynthetic enzyme for NADP+, and NAMPT, which replenishes the NAD+ pool, was higher in carns1-KO mice brains than in controls. Our observations suggest that HDs cell-autonomously protect oligodendrocytes from oxidative stress, with implications for demyelinating diseases.
RESUMEN
The peptidoglycan pathway represents one of the most successful antibacterial targets with the last critical step being the flipping of carrier lipid, undecaprenyl phosphate (C55-P), across the membrane to reenter the pathway. This translocation of C55-P is facilitated by DedA and DUF368 domain-containing family membrane proteins via unknown mechanisms. Here, we employ native mass spectrometry to investigate the interactions of UptA, a member of the DedA family of membrane protein from Bacillus subtilis, with C55-P, membrane phospholipids, and cell wall-targeting antibiotics. Our results show that UptA, expressed and purified in Escherichia coli, forms monomer-dimer equilibria, and binds to C55-P in a pH-dependent fashion. Specifically, we show that UptA interacts more favorably with C55-P over shorter-chain analogs and membrane phospholipids. Moreover, we demonstrate that lipopeptide antibiotics, amphomycin and aspartocin D, can directly inhibit UptA function by out-competing the substrate for the protein binding, in addition to their propensity to form complex with free C55-P. Overall, this study shows that UptA-mediated translocation of C55-P is potentially mediated by pH and anionic phospholipids and provides insights for future development of antibiotics targeting carrier lipid recycling.
Asunto(s)
Antibacterianos , Bacillus subtilis , Proteínas Bacterianas , Fosfatos de Poliisoprenilo , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/metabolismo , Antibacterianos/farmacología , Antibacterianos/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Fosfatos de Poliisoprenilo/metabolismo , Lipopéptidos/farmacología , Lipopéptidos/metabolismo , Proteínas de la Membrana/metabolismo , Unión Proteica , Escherichia coli/metabolismo , Escherichia coli/efectos de los fármacosRESUMEN
Autophagy is a conserved self-digestion process, which governs regulated degradation of cellular components. Autophagy is upregulated upon energy shortage sensed by AMP-dependent protein kinase (AMPK). Autophagy activators might be contemplated as therapies for metabolic neurodegenerative diseases and obesity, as well as cancer, considering tumor-suppressive functions of autophagy. Among them, 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr), a nucleoside precursor of the active phosphorylated AMP analog, is the most commonly used pharmacological modulator of AMPK activity, despite its multiple reported "off-target" effects. Here, we assessed the autophagy/mitophagy activation ability of a small set of (2'-deoxy)adenosine derivatives and analogs using a fluorescent reporter assay and immunoblotting analysis. The first two leader compounds, 7,8-dihydro-8-oxo-2'-deoxyadenosine and -adenosine, are nucleoside forms of major oxidative DNA and RNA lesions. The third, a derivative of inactive N6-methyladenosine with a metabolizable phosphate-masking group, exhibited the highest activity in the series. These compounds primarily contributed to the activation of AMPK and outperformed AICAr; however, retaining the activity in knockout cell lines for AMPK (ΔAMPK) and its upstream regulator SIRT1 (ΔSIRT1) suggests that AMPK is not a main cellular target. Overall, we confirmed the prospects of searching for autophagy activators among (2'-deoxy)adenosine derivatives and demonstrated the applicability of the phosphate-masking strategy for increasing their efficacy.
RESUMEN
Dental implants, recognized for their enhanced functionality and aesthetic outcomes, are susceptible to peri-implant mucositis and subsequent peri-implantitis when oral hygiene is inadequate. Effective biofilm management is critical to prevent and manage these prevalent conditions and promote implant longevity. Materials with a two-dimensional (2D) structure have demonstrated robust antimicrobial properties. Among these, 2D magnesium phosphates have garnered significant attention due to their additional biocompatibility and osteoconductive properties. This case series explores the application of a thixotropic inorganic hydrogel, composed of 2D magnesium phosphate, in the surgical treatment of dental implant infections. The hydrogel was used for surgical dental implant decontamination in patients diagnosed with peri-implantitis characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. The study encompassed eight cases with a history of peri-implantitis. Clinical measurements were recorded before and after treatment, including bleeding on probing, suppuration, and probing depth. Radiographic evaluations were conducted to assess the exposure of implant threads. The findings revealed a statistically significant decrease in probing depth, bleeding on probing, and the number of exposed implant threads following treatment with the magnesium phosphate hydrogel, though the exact role of the hydrogel in these improvements warrants further exploration.
RESUMEN
Epidemiological evidence links exposure to 2-ethylhexyl diphenyl phosphate (EHDPP) with lipid metabolic disruption, typically attributed to nuclear receptors, while the role of membrane receptors remains underexplored. This study explored the role of adiponectin receptor 1 (AdipoR1) in EHDPP-induced lipid metabolic disturbances. We examined EHDPP's binding affinity and transcriptional impact on AdipoR1. AdipoR1 knockdown (AdipoR1kd) human liver cells and coculture experiments with AdipoR1 activator (AdipoRon) were used to investigate the effect and the mechanism. EHDPP disrupted triglyceride and phospholipid synthesis and altered corresponding gene expression, mirroring effects in AdipoR1kd cells but diminishing in EHDPP-treated AdipoR1kd cells. RNA sequencing revealed that EHDPP primarily disrupted oxidative phosphorylation and insulin signaling dependent on AdipoR1. Mechanistically, EHDPP interacted with AdipoR1 and reduced AdipoR1 protein levels at 10-7 mol/L or higher, weakening the activation of the calmodulin dependent protein kinase ß (CaMKKß)/AMPK/acetyl CoA carboxylase pathway. Furthermore, EHDPP pretreatment blocked the increase in Ca2+ flux and the corresponding kinase CaMKKß, as well as liver kinase B1 (LKB1) activation induced by AdipoRon, which is necessary for AMPK activation. Collectively, these findings demonstrate that EHDPP-induced lipid imbalance is partially dependent on AdipoR1, expanding the understanding of environmental metabolic disruptors beyond nuclear receptors.
RESUMEN
Acute myeloid leukemia (AML) is a type of blood cancer of the myeloid cell lineage. Obesity is characterized by an increase in body weight that results in excessive fat accumulation. Obesity has been associated with an increased incidence of many cancers, including blood cancers. This study evaluated the role obesity in AML progression in a novel transgenic mouse model developed by crossing Flt3ITD mice with Lepob/ob mice. Leukemia burden was augmented in obese AML mice. In addition, it was determined that obesity upregulated the ceramide-mediated and ceramide-1-phosphate-mediated NADPH oxidase 2 (NOX2). Notably, increased oxidative pathways has been attributed to disease progression in AML. Taken together, this study demonstrates a direct link between obesity and the progression of AML in part by augmenting the ceramide mediated NOX2.
RESUMEN
Vitamin B12 is involved in many important biochemical reactions for humans, and its deficiency can lead to serious diseases. The industrial production of vitamin B12 is achieved through microbial fermentation. In this work, we determine the crystal structures of the l-threonine-O-3-phosphate (Thr-P) decarboxylase CobC from Sinorhizobium meliloti (SmCobC), an industrial vitamin B12-producing bacterium, in apo form and in complex with a reaction intermediate. Our structures supported the Thr-P decarboxylase activity of SmCobC and revealed that the positively charged substrate-binding pocket between the large and small domains determines its substrate selectivity for Thr-P. Moreover, our results provided evidence for the proposition that the AP-P linker is formed by direct incorporation of AP-P in the biosynthetic pathway of vitamin B12 in S.meliloti.
RESUMEN
Arginine (Arg), a safe basic amino acid, modulates interprotein interactions and impacts the processing characteristics of myofibrillar proteins (MP) in meat products, as numerous studies have demonstrated. This study aimed to explore the effects of varying concentrations of Arg (0.025, 0.050, 0.100, 0.200 %) on the physicochemical properties and gel behavior of yak MP. Utilizing yak MP as the substrate, we assessed and analyzed the physicochemical attributes and gel performance of the MP-Arg composite system. The findings revealed that Arg facilitates MP unfolding and internal group exposure, effectively mitigating oxidative tertiary structure alterations. Arg exerts potent antioxidant activity on MP, augmenting their water-holding capacity, which ameliorates gel properties. In this experiment, 0.05 % Arg maximally inhibited oxidative damage to MP, with protection being concentration-dependent. Collectively, these findings suggest that Arg effectively inhibits the oxidative degradation of MP structure and promotes the formation of enhanced gel characteristics.
RESUMEN
Autoimmune hemolytic anemia (AIHA) and glucose-6-phosphate dehydrogenase (G6PD) deficiency are two distinct causes of hemolysis in children and a combination of both diseases is considered rare, especially in early infancy. We present such a rare case of severe AIHA in an infant with G6PD deficiency in the setting of Escherichia coli urinary tract infection and recent pneumococcal vaccination history, with the goal of analyzing potential links between them, examining the causative role of vaccines, and reviewing available literature.
RESUMEN
Vital pulp treatment (VPT) is crucial for preserving the health and function of the tooth in cases where the pulp tissue remains vital despite exposure. Various materials are introduced for this purpose. However, challenges such as low strength, high solubility, and tooth discoloration persist. Methylmethacrylate-based cement (MC) offers excellent sealing ability, feasibility, and mechanical properties, making it a promising alternative for VPT. Phosphate-based glass (PBG) has the potential to promote hard tissue regeneration by releasing key inducers, phosphorus (P) and calcium (Ca), for reparative odontogenesis. This study investigates PBG-integrated MC (PIMC) by characterizing its properties, assessing human dental pulp stem cell activity related to initial inflammatory adaptation and odontogenic differentiation, and evaluating hard tissue formation using an in vivo dog pulpotomy model. Results indicate that a 5% PBG-integrated MC (5PIMC) maintains the physicochemical properties of MC. Furthermore, 5PIMC demonstrates cytocompatibility, excellent expression of osteo/odontogenic markers, and resistance to inflammatory markers, significantly outperforming MC. Enhanced hard tissue formation is observed in the dental pulp of mongrel dog teeth treated with 5PIMC. These findings suggest that 5PIMC could be an optimal and suitable material for reparative odontogenesis through VPT.
RESUMEN
BACKGROUND: Minimally invasive approaches are the standard for treatment of upper urinary tract uroliths in humans. OBJECTIVE: To describe the medical dissolution of upper urinary tract uroliths in a series of dogs and report clinical outcomes. ANIMALS: 6 female dogs (9 kidneys). METHODS: Retrospective case series. A review of medical records in dogs that underwent medical dissolution of upper urinary tract uroliths utilizing diet, administration of antibiotics, and double-pigtail ureteral stent(s) placement, when indicated, was performed. Medical management was generally continued for 4 weeks beyond urolith dissolution. Information on biochemical, microbiological, imaging, and clinical outcomes before and after dissolution were recorded. RESULTS: Six dogs (9 kidneys) were included with bilateral (3) or unilateral (3) nephrolithiasis, ureterolithiasis, or a combination. A ureteral stent(s) was placed endoscopically in 5/6 dogs (6/9 kidneys) for obstructive ureterolithiasis (n = 5) or a nonobstructive massive nephrolith (n = 1). All dogs had a positive urine culture of Staphylococcus pseudintermedius with a median urine pH of 7.25 (range, 6.5-8) and 4/5 had pyonephrosis. All dogs had initial evidence of urolith dissolution at a median of 1.1 months (range, 0.42-5.9), with complete dissolution of ureteroliths at a median of 3.9 months (range, 1.5-7.6), nephroliths at 5.3 months (range, 1.5-7.6), and lower urinary tract uroliths at 0.87 months (range, 0.42-5.9). Stents were removed in 3/6 once dissolution was documented. The median follow-up time was 519 days (range, 177-2492 days). CONCLUSION AND CLINICAL IMPORTANCE: Medical dissolution and decompression of upper urinary tract struvite uroliths should be considered a minimally invasive treatment for dogs before more invasive options.
RESUMEN
Triphenyl phosphate (TPP) and polystyrene nanoplastics (PSNPs) are prevalent freshwater contaminants obtained mainly from food packaging, textiles and electronics. Algal extracellular polymeric substances (EPS), a part of natural organic matter, may influence these pollutants' behaviour and toxicity. The presence of EPS can enhance the aggregation of TPP-PSNP mixtures, and reduce the bioavailability, and thus the toxicity potential. Understanding the mutual interactions between TPP, PSNPs, and EPS in the aquatic environment is a prerequisite for the environmental risk assessment of these chemicals. The study examines the toxicity effects of various surface-modified PSNPs (1 mg/L of plain, animated, and carboxylated) and TPP (0.05, 0.5, and 5 mg/L) in pristine and combined forms on freshwater microalgae, Chlorella sp., as a model organism. The physical-chemical interactions of algal EPS (10 mg/L) with PSNPs and TPP and their mixtures were studied. The toxicity potential of the PSNPs was estimated by quantifying growth inhibition, oxidative stress, antioxidant activity, and photosynthesis in the cells. TPP toxicity increased in the presence of the PSNPs, however the addition of algal EPS reduced the combined toxic effects. EPS plays a protective role by reducing oxidative stress and enhancing photosynthetic efficiency in the algal cells. The Pearson modeling analysis indicated a positive correlation between growth inhibition, and reactive oxygen species, malondialdehyde production. The cluster heatmap and correlation mapping revealed a strong correlation among the oxidative stress, growth inhibition, and photosynthetic parameters. The study clearly highlights the potential of EPS in mitigating the risk of mixed emerging pollutants in the aquatic environment.