26 research outputs found

    MitoQ Modulates Lipopolysaccharide-Induced Intestinal Barrier Dysfunction via Regulating Nrf2 Signaling

    No full text
    Background. Gut barrier dysfunction with alterant mucosal permeability during sepsis is a challenge problem in clinical practice. Intestinal epithelial cells (IECs) are strongly involved in mucosal oxidative stress and inflammatory response. The current study aimed at investigating the effect of MitoQ, a mitochondrial targeted antioxidant, in the treatment of intestinal injury and its potential mechanism during sepsis. Methods. 30 minutes before sepsis induction by lipopolysaccharide (LPS) treatment, mice were treated with MitoQ. Intestinal histopathology, mucosal permeability, inflammatory cytokines, and mucosal barrier proteins were evaluated in the present study. Results. MitoQ pretreatment significantly decreased the levels of plasma diamine oxidase, D-lactate, and intestinal histological damage and markedly restored the levels of tight junction proteins (ZO-1 and occludin) following LPS challenge. Furthermore, MitoQ inhibited the LPS-induced intestinal oxidative stress and inflammatory response, evidenced by increased levels of intestinal superoxide dismutase and glutathione, and decreased levels of intestinal IL-1, IL-6, TNF-α, and nitric oxide levels. Mechanically, we found that MitoQ inhibited the oxidative stress via activating nuclear factor E2-related factor 2 (Nrf2) signaling pathway and its downstream antioxidant genes, including HO-1, NQO-1, and GCLM. Conclusions. MitoQ exerts antioxidative and anti-inflammatory effects against sepsis-associated gut barrier injury by promoting Nrf2 signaling pathway

    Exploration on the origin of enhanced piezoelectric properties in transition-metal ion doped KNN based lead-free ceramics

    No full text
    In this work, we studied effects of Ni2O3 and Co2O3 doping on crystal structures, microstructures, orthorhombic and tetragonal phase transition temperature (To-t), and electrical properties of [Li0.06(Na0.57K0.43)0.94][Ta0.05(Sb0.06Nb0.94)0.95]O3 (LNKTSN) lead-free ceramics. The experimental results showed that the Ni2O3 addition with appropriate amount could shift the To-t downwards to the room temperature, and thus obviously increasing the room-temperature piezoelectric coefficient (d33), dielectric coefficient (εr) and electromechanical coupling coefficient (kp) of the LNKTSN ceramics. These were consistent with previous experimental results obtained in Fe2O3 doped LNKTSN ceramics. On the contrary, Co3+ doping shifted continuously the To-t upward and deteriorated obviously piezoelectric properties of LNKTSN ceramics. Fe, Co and Ni had similar ion radii and were expected to result in the same (donor or acceptor) doping effects on electrical properties of LNKTSN ceramics. The different doping effects between Co3+ (deterioration) and Ni3+ or Fe3+ (improvement) on the electrical properties of LNKTSN ceramics suggested that the coexistence of orthorhombic and tetragonal phases at room temperature due to downward shift of To-t, rather than ion doping (donor or acceptor doping) effects was the main cause for enhanced room-temperature piezoelectric properties. This conclusion can be extended to all KNN-based materials in general, thus offering principle guide for future development of new lead-free materials with good piezoelectric properties

    Optimization of fermentative biohydrogen production by response surface methodology using fresh leachate as nutrient supplement

    No full text
    Fresh compost leachate was used as a nutrients source to facilitate anaerobic fermentative hydrogen production from glucose inoculated with mixed culture. The optimum condition for hydrogen production was predicted by response surface methodology (RSM). The model showed the maximum cumulative hydrogen volume (469.74 mL) and molar hydrogen yield (1.60 mol H-2/mol glucose) could be achieved at 6174.93 mg/L glucose and 3383.20 mg COD/L leachate. According to the predicted optimal condition, four tests were carried out to validate the predicted values and evaluate the leachate's effect on co-fermentation with juice wastewater. A maximum cumulative hydrogen volume of 587.05 +/- 15.08 mL was obtained in co-fermentation test, and the molar hydrogen yield reached 2.06 +/- 0.06 mol H-2/mol glucose. The co-fermentation of fresh leachate and glucose/juice wastewater was a combination of acetic acid and butyric acid type-fermentation. The results demonstrated that leachate can serve as a nutrients source for biohydrogen production. (C) 2011 Elsevier Ltd. All rights reserved

    High-performance Ga2O3/FTO-based self-driven solar-blind UV photodetector with thickness-optimized graphene top electrode

    No full text
    Self-driven solar-blind ultraviolet photodetectors (SBUVPDs) have attracted considerable interest for their superior sensitivity and operation flexibility. Herein, we demonstrate realization of a simple vertical-structured self-driven SBUVPD by pulsed laser deposition of β-Ga2O3 thin film on commercially available fluorine doped tin oxide (FTO) substrate, adopting multi-layer graphene (MLG) as the top electrode. On the one hand, the introduction of MLG with both high electrical conductance and UV transmittance greatly enhances photocurrent and responsivity of the photodetector. On the other hand, the dominating Schottky contact between Ga2O3 and MLG creates a net built-in electric field, leading to self-driven photoresponse of the device with improved response speed. With optimized thickness (8 ± 2 single layers of graphene) of the top electrode, the device exhibits the best detection performance that is superior to most of previous reports towards UV illumination at 0 V bias. It delivers a photocurrent as high as 31 nA towards 250 nm-light with ultra-fast response speed (τr = 2 ms, τd = 8.8 ms), and exhibits a maximum responsivity of 9.2 mA/W and detectivity of 5.27 × 1011 Jones under 230 nm-light illumination, while the response cuts off at light wavelength of 261 nm, falling completely within the solar blind band. In addition, the device has good multi-cycle repeatability and stability, showing great application potential in solar-blind UV detection

    Deep Separation of Benzene from Cyclohexane by Liquid Extraction Using Ionic Liquids as the Solvent

    No full text
    Separation of benzene and cyclohexane is one of the most important and difficult processes in the petrochemical industry, especially for low benzene concentration. In this work, three ionic liquids (ILs), [Bmim]­[BF<sub>4</sub>], [Bpy]­[BF<sub>4</sub>], and [Bmim]­[SCN], were investigated as the solvent in the extraction of benzene from cyclohexane. The corresponding ternary liquid–liquid equilibria (LLE) were experimentally determined at <i>T</i> = 298.15 K and atmospheric pressure. The LLE data were correlated with the nonrandom two-liquid model, and the parameters were fitted. The separation capabilities of the ILs were evaluated in terms of the benzene distribution coefficient and solvent selectivity. The effect of the IL structure on the separation was explained based on a well-founded physical model, COSMO-RS. Finally, the extraction processes were defined, and the operation parameters were analyzed. It shows that the ILs studied are suitable solvents for the extractive separation of benzene and cyclohexane, and their separation efficiency can be generally ranked as [Bmim]­[BF<sub>4</sub>] > [Bpy]­[BF<sub>4</sub>] > [Bmim]­[SCN]. The extraction process for a feed with 15 mol % benzene was optimized. High product purity (cyclohexane 0.997) and high recovery efficiency (cyclohexane 96.9% and benzene 98.1%) can be reached

    Peroxiredoxin-1 as a molecular chaperone that regulates glutathione S-transferase P1 activity and drives mutidrug resistance in ovarian cancer cells

    No full text
    Ovarian cancer is among the most prevalent gynecological malignancies around the globe. Nonetheless, chemoresistance continues to be one of the greatest obstacles in the treatment of ovarian cancer. Therefore, understanding the mechanisms of chemoresistance and identifying new treatment options for ovarian cancer patients is urgently required. In this study, we found that the mRNA and protein expression levels of PRDX1 were significantly increased in cisplatin resistant A2780/CDDP cells. Cell survival assays revealed that PRDX1 depletion substantially increased ovarian cancer cell sensitivity to cisplatin, docetaxel, and doxorubicin. Additionally, PRDX1 significantly increased GSTP1 activity, resulting in multidrug resistance. Biochemical experiments showed that PRDX1 interacted with GSTP1 through Cysteine 83, which regulated GSTP1 activity as well as chemotherapy resistance in ovarian cancer cells. Our findings indicate that the molecular chaperone activity of PRDX1 is a promising new therapeutic target for ovarian cancer

    A simplified flow cytometric assay identifies children with acute lymphoblastic leukemia who have a superior clinical outcome

    No full text
    Bone marrow normal lymphoid progenitors (CD19+, CD10+, and/or CD34+) are exquisitely sensitive to corticosteroids and other antileukemic drugs. We hypothesized that, in patients with B-lineage acute lymphoblastic leukemia (ALL), cells with this phenotype detected early in treatment should be leukemic rather than normal. We therefore developed a simple and inexpensive flow cytometric assay for such cells and prospectively applied it to bone marrow samples collected on day 19 from 380 children with B-lineage ALL. In 211 patients (55.5%), these cells represented 0.01% or more of the mononuclear cells; results correlated remarkably well with those of more complex flow cytometric and molecular minimal residual disease (MRD) evaluations. Among 84 uniformly treated children, the 10-year incidence of relapse or remission failure was 28.8% ± 7.1% (SE) for the 42 patients with 0.01% or more leukemic cells on day 19 detected by the simplified assay versus 4.8% ± 3.3% for the 42 patients with lower levels (P = .003). These assay results were the strongest predictor of outcome, even after adjustment for competing clinicobiologic variables. Thus, this new assay would enable most treatment centers to identify a high proportion of children with ALL who have an excellent early treatment response and a high likelihood of cure. (Blood. 2006;108:97-102

    An Overview of Mutual Solubility of Ionic Liquids and Water Predicted by COSMO-RS

    No full text
    To properly screen and use ionic liquids (ILs) as environmental-friendly solvents in chemical reactors and separation processes, the knowledge of their solubilities with water is essential. In the present work, mutual solubilities of 1500 ILs (50 cations, 30 anions) with water at 298.15 K were predicted by using the conductor-like screening model for real solvents (COSMO-RS) as a thermodynamic model. On the basis of the COSMO-RS calculations, the influence of the types of anion and cation, side chain modifications and substituent groups on the mutual solubility with water was extensively analyzed. The data obtained can be used for the prescreening of ILs as solvent candidates. Moreover, to understand the intrinsic solubility behavior in detail, different types of molecular interactions between ILs and water in solution were compared on the basis of the determination of multiple water–IL interaction energies from COSMO-RS computation. The results confirm that hydrogen bonding interactions between anions and water molecules have the dominant influence on the solubility. Finally, for the purpose of fast solubility estimation and solvent selection, COSMO-RS derived molecular descriptors which indicate the strength of anionic HB acceptors were calculated for typical anions and anion families
    corecore