11 research outputs found

    Assessment of Ozonation and Biofiltration as a Membrane Pre-treatment at a Full-scale Drinking Water Treatment Plant

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    Membrane technologies are gaining popularity for drinking water treatment; however, fouling remains a major constraint as it can increase operational cost and shorten membrane service life. An important source of foulants for low pressure membranes (LPMs) is natural organic matter (NOM) which is present to varying degrees in all surface waters. Membrane fouling attributable to NOM can be managed by using appropriate pre-treatment(s). Among the new developments in membrane technologies for drinking water applications has been the integration of different pre-treatment processes in order to achieve optimal membrane performance and minimum lifecycle cost. The process combination of ozonation and biological filtration (biofiltration) appears to be a promising integrated pre-treatment for LPMs as both processes have been shown to individually be able to reduce LPM fouling. However, the process combination is neither commonly employed nor well-studied. The goals of this research were to assess the fouling control capacity of ozonation-biofiltration as an integrated pre-treatment process for ultrafiltration (UF) membranes, evaluate the role of ozone in the ozonation-biofiltration-membrane (OBM) process combination, and investigate the effect of water quality and NOM on the process. The approach involved the operation of three UF pilot plants and long-term water quality and biomass monitoring at the Lakeview Water Treatment Plant (WTP), which is located in Southern Ontario and is one of the few WTPs in the world that employs an ozonation, biofiltration, and ultrafiltration process sequence. A novel Liquid Chromatography-Organic Carbon Detection (LC-OCD) method was used to characterize different NOM fractions, including biopolymers, humic substances, building blocks, low molecular weight (LMW) acids and humics, and LMW neutrals. During this 16-month investigation, the ozonation-biofiltration process combination achieved good turbidity reduction but only minimal dissolved organic carbon (DOC) removal. In addition, the operation of ozonation (on vs. off) clearly impacted both biomass quantity and activity within the BACCs as measured by adenosine triphosphate (ATP) and fluorescein diacetate (FDA), respectively. This is because ozone can decrease the hydrophobicity of DOC in water as seen by a 43% reduction in specific ultraviolet absorbance through ozonation. Among all NOM factions measured by LC-OCD, biopolymers, which made up 13% of DOC, appeared to be the only one responsible for UF membrane fouling. An average of 60% of the biopolymers reaching the full- and pilot-scale UF membranes were retained. The concentration of biopolymers in membrane influent was found to be correlated to the hydraulically reversible fouling rate, while hydraulically irreversible fouling was largely affected by particulate/colloid content. The integrated ozonation–biofiltration pre-treatment process substantially reduced hydraulically irreversible fouling by removing substances measured as turbidity. Furthermore, ozonation was found to be able to enhance UF membrane fouling control as it can decrease biopolymer retention by downstream membranes (independently of biofilter efficiency). This research provides valuable information for the water treatment sector on LPM fouling and its control. Overall, the full-scale integrated ozonation-biofiltration pre-treatment process successfully reduced downstream LPM hydraulically reversible and irreversible fouling, and as such the example of the Lakeview WTP can be used to guide designers of other municipal drinking water membrane installations. Information on the concentration and variation of biopolymers in source water is important for membrane water treatment applications, and biofilters should be optimized for better biopolymer removal. These findings provide useful insight into the design and operation of membrane water treatment facilities

    Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System

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    The health of animals, including humans, is dependent on their resident microbiota, but the complexity of the microbial communities makes these associations difficult to study in most animals. Exceptionally, the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B. aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to determine the alterations of proteins induced by these treatments. We found that these perturbations resulted in significant changes to the abundance of 15 metabolites and 238 proteins. Ten (67%) of the metabolites with altered abundance were amino acids, with nonessential amino acids increased and essential amino acids decreased by both perturbations. Over-represented proteins in the perturbed treatments included catabolic enzymes with roles in amino acid degradation and glycolysis, various cuticular proteins, and a C-type lectin and regucalcin with candidate defensive roles. This analysis demonstrates the central role of essential amino acid production in the relationship and identifies candidate proteins and processes underpinning the function and persistence of the association

    Ginsenoside RK1 Induces Ferroptosis in Hepatocellular Carcinoma Cells through an FSP1-Dependent Pathway

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    Background: Hepatocellular carcinoma (HCC), currently ranking as the third most lethal malignancy, poses a grave threat to human health. Ferroptosis, a form of programmed cell demise, has emerged as a promising therapeutic target in HCC treatment. In this study, we investigated the impact of ginsenoside RK1 on ferroptosis induction in HCC cells and elucidated the underlying mechanisms. Methods: The HCC cell line HepG2 was utilized to evaluate the effects of ginsenoside RK1. Distinct dosages of ginsenoside RK1 (25 μM, 50 μM, and 100 μM) were selected based on half-maximal inhibitory concentration (IC50) values. Cellular viability was assessed using a CCK8 assay, cytotoxicity was measured via lactate dehydrogenase (LDH) release assay, and colony-forming ability was evaluated using the clone formation assay. Various inhibitors targeting apoptosis (Z-VAD-FMK 20 μM), necrosis (Nec-1, 10 μM), and ferroptosis (Fer-1, 10 μM; Lip-1, 1 μM) were employed to assess ginsenoside RK1’s impact on cell demise. Intracellular levels of key ions, including glutathione (GSH), malondialdehyde (MDA), and iron ions, were quantified, and the protein expression levels of ferroptosis-related genes were evaluated. The sensitivity of HCC cells to ferroptosis induction by ginsenoside RK1 was examined following the overexpression and silencing of the aforementioned target genes. Results: Ginsenoside RK1 exhibited an inhibitory effect on HCC cells with an IC50 value of approximately 20 μM. It attenuated cellular viability and colony-forming capacity in a dose-dependent manner, concurrently reducing intracellular GSH levels and increasing intracellular Malondialdehyde (MDA) and iron ion contents. Importantly, cell demise induced by ginsenoside RK1 was specifically counteracted by ferroptosis inhibitors. Furthermore, the modulation of Ferroptosis suppressor protein 1 (FSP1) expression influenced the ability of ginsenoside RK1 to induce ferroptosis. FSP1 overexpression or silencing enhanced or inhibited ferroptosis induction by ginsenoside RK1, respectively. Conclusions: Ginsenoside RK1 enhances ferroptosis in hepatocellular carcinoma through an FSP1-dependent pathway

    TSG-6 Inhibits the NF-κB Signaling Pathway and Promotes the Odontogenic Differentiation of Dental Pulp Stem Cells via CD44 in an Inflammatory Environment

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    In pulpitis, dentinal restorative processes are considerably associated with undifferentiated mesenchymal cells in the pulp. This study aimed to investigate strategies to improve the odonto/osteogenic differentiation of dental pulp stem cells (DPSCs) in an inflammatory environment. After pretreatment of DPSCs with 20 ng/mL tumor necrosis factor-induced protein-6 (TSG-6), DPSCs were cultured in an inflammation-inducing solution. Real-time polymerase chain reaction and Western blotting were performed to measure the expression levels of nuclear factor kappa B (NF-κB) and odonto/osteogenic differentiation markers, respectively. Cell Counting Kit-8 and 5-ethynyl-2′-deoxyuridine assays were used to assess cell proliferation and activity. Subcutaneous ectopic osteogenesis and mandibular bone cultures were performed to assess the effects of TSG-6 in vivo. The expression levels of odonto/osteogenic markers were higher in TSG-6-pre-treated DPSCs than nontreated DPSCs, whereas NF-κB-related proteins were lower after the induction of inflammation. An anti-CD44 antibody counteracted the rescue effect of TSG-6 on DPSC activity and mineralization in an inflammatory environment. Exogenous administration of TSG-6 enhanced the anti-inflammatory properties of DPSCs and partially restored their mineralization function by inhibiting NF-κB signaling. The mechanism of action of TSG-6 was attributed to its interaction with CD44. These findings reveal novel mechanisms by which DPSCs counter inflammation and provide a basis for the treatment of pulpitis

    Electrospinning Chitosan/Fe-Mn Nanofibrous Composite for Efficient and Rapid Removal of Arsenite from Water

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    Efficient removal of extremely mobile and toxic As(III) from water is a challenging but critical task. Herein, we developed a functionalized sorbent of chitosan nanofiber with iron–manganese (Fe-Mn@CS NF) using a one-step hybrid electrospinning approach to remove trace As(III) from water. Batch adsorption studies were performed to determine the adsorption efficiency under a variety of conditions, including contact time, starting concentration of As(III), ionic strength, and the presence of competing anions. The experimental results demonstrated that the concentration of As(III) dropped from 550 to less than 1.2 µg/L when using 0.5 g/L Fe-Mn@CS NF. This demonstrates the exceptional adsorption efficiency (99.8%) of Fe-Mn@CS NF for removing As(III) at pH 6.5. The kinetic tests revealed that the adsorption equilibrium was reached in 2.6 h, indicating a quick uptake of As(III). The ionic strength effect analysis showed that the adsorbed As(III) formed inner-sphere surface complexes with Fe-Mn@CS NF. The presence of SO42− or F− had a negligible impact on As(III) uptake, while the presence of PO43− impeded As(III) absorption by competing for adsorption sites. The exhausted sorbent could be effectively regenerated with a dilute NaOH solution. Even after 10 cycles of regenerating Fe-Mn@CS NF, the adsorption efficiency of As(III) in natural groundwater was maintained over 65%. XPS and FTIR analyses show that the presence of M–OH and C–O groups on the sorbent surface is essential for removing As(III) from water. Overall, our study highlights the significant potential of Fe-Mn@CS NF for the efficient and quick elimination of As(III) from water

    Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System

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    The health of animals, including humans, is dependent on their resident microbiota, but the complexity of the microbial communities makes these associations difficult to study in most animals. Exceptionally, the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B. aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to determine the alterations of proteins induced by these treatments. We found that these perturbations resulted in significant changes to the abundance of 15 metabolites and 238 proteins. Ten (67%) of the metabolites with altered abundance were amino acids, with nonessential amino acids increased and essential amino acids decreased by both perturbations. Over-represented proteins in the perturbed treatments included catabolic enzymes with roles in amino acid degradation and glycolysis, various cuticular proteins, and a C-type lectin and regucalcin with candidate defensive roles. This analysis demonstrates the central role of essential amino acid production in the relationship and identifies candidate proteins and processes underpinning the function and persistence of the association

    Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System

    Get PDF
    The health of animals, including humans, is dependent on their resident microbiota, but the complexity of the microbial communities makes these associations difficult to study in most animals. Exceptionally, the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B. aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to determine the alterations of proteins induced by these treatments. We found that these perturbations resulted in significant changes to the abundance of 15 metabolites and 238 proteins. Ten (67%) of the metabolites with altered abundance were amino acids, with nonessential amino acids increased and essential amino acids decreased by both perturbations. Over-represented proteins in the perturbed treatments included catabolic enzymes with roles in amino acid degradation and glycolysis, various cuticular proteins, and a C-type lectin and regucalcin with candidate defensive roles. This analysis demonstrates the central role of essential amino acid production in the relationship and identifies candidate proteins and processes underpinning the function and persistence of the association

    Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System

    No full text
    The health of animals, including humans, is dependent on their resident microbiota, but the complexity of the microbial communities makes these associations difficult to study in most animals. Exceptionally, the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B. aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to determine the alterations of proteins induced by these treatments. We found that these perturbations resulted in significant changes to the abundance of 15 metabolites and 238 proteins. Ten (67%) of the metabolites with altered abundance were amino acids, with nonessential amino acids increased and essential amino acids decreased by both perturbations. Over-represented proteins in the perturbed treatments included catabolic enzymes with roles in amino acid degradation and glycolysis, various cuticular proteins, and a C-type lectin and regucalcin with candidate defensive roles. This analysis demonstrates the central role of essential amino acid production in the relationship and identifies candidate proteins and processes underpinning the function and persistence of the association

    Collegio, cultura e regime

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    Il saggio ripercorre la vita all'interno del Collegio universitario Ghislieri di Pavia negli anni del fascismo, delineando il rapporto tra un'antica istituzione di merito e la politica universitaria del regime fascista: formazione culturale degli alunni, dissenso politico, percorsi individuali
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