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1.
J Hazard Mater ; : 127821, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34810004

RESUMO

Hydrothermal carbonation carbon (HTCC) is emerging as a promising alternative for photocatalytic removal of contaminants from water. However, the catalytic activity of HTCC is limited by its poor charge transfer ability, and its photocatalytic mechanism remains unclear. Herein, a unique photosensitization-like mechanism was firstly found on Fe modified HTCC (Fe-HTCC) derived from glucose for effective removal of organic pollutants. Under visible light illumination, the organic pollutant coordinated with Fe-HTCC enabled electrons transfer from its highest occupied molecular orbital (HOMO) to conduction band (CB) of Fe-HTCC, which not only oxidized pollutant itself, but also generated oxygen-centered radical for reducing O2 into O2•- towards pollutant removal. The degradation kinetic constant of sulfamethoxazole (SMX) over Fe-HTCC was about 1024.4 and 20.5 times higher than that of HTCC and g-C3N4, respectively. The enhanced performance of Fe-HTCC was originated from dual role of Fe modification: one is to boost the electron-deficient C sites which prefer to coordinate with amino or hydroxyl of pollutants; the other is to enhance the linkage of discrete polyfuran chains in Fe-HTCC for effective electron transfer from pollutant to Fe-HTCC. This work provides new insight into the synthesis and mechanism of HTCC-based high-efficiency photocatalyst for water decontamination.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34785049

RESUMO

Coupling membrane filtration with peroxymonosulfate (PMS) activation is promising to overcome the selectivity-permeability trade-off in membrane-based water treatment. However, the PMS catalytic efficiency of membrane still needs improvement to offset the insufficient reaction time during filtration process. Herein, an oxidized carbon nanotube intercalated nitrogen doped reduced graphene oxide (NRGO-OCNT) membrane with PMS activation function was firstly designed and prepared, which confined PMS activation in membrane interlayer for enhanced water treatment. The influence of confinement scale on membrane performance was studied through changing the OCNT intercalation ratio. Under the optimal confinement condition, the NRGO-OCNT membrane filtration integrated with PMS activation (MFPA) could realize 100% 4-chlorophenol removal at a high permeate flux of 290.2 L m-2 h-1 bar-1 (retention time of only 0.36 s), whose performance was 2.8, 1.7 and 5.0 times higher than that of filtration alone, NRGO MFPA (excessive confinement) and NRGO-OCNT powder-based batch reaction (no confinement), respectively. Moreover, NRGO-OCNT MFPA preferentially removed smaller-sized organics which easily entered and diffused in confined interlayer. The outstanding performance of NRGO-OCNT MFPA was owing to the nanoconfinement effect in appropriate confined interspacing, where the mass transfer rate of reactants was greatly boosted for enhanced generation of SO4- and OH towards pollutant.

3.
J Cancer ; 12(22): 6629-6639, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659553

RESUMO

Cancer stem cells (CSCs) are characterized by self-renewal and unlimited proliferation, providing a basis for tumor occurrence, metastasis, and recurrence. Because CSCs are highly resistant to conventional chemotherapy and radiotherapy, various immunotherapies, particularly chimeric antigen receptor T cell (CAR-T) therapy and dendritic cell (DC)-based vaccine therapy, are currently being developed. Accordingly, in this study, we evaluated programmed cell death ligand-1 (PD-L1) expression in colorectal CSCs (CCSCs) and non-CCSCs and designed a combination immunotherapy synchronously utilizing PD-L1-CAR-T cells together with CCSC-DC vaccine-sensitized T cells for the treatment of colorectal cancer. PD-L1-CAR-T cells specifically recognized the PD-L1 molecule on CCSCs by binding to the extracellular domain of programmed cell death-1. The CCSC-DC vaccine was prepared using CCSC lysates. We found that aldehyde dehydrogenase 1 (ALDH1)-positive CCSCs were abundant in samples from patient tumor tissues and cancer cell lines. Moreover, PD-L1 was highly expressed in ALDH1-positive CCSCs compared with that in non-CCSCs. Monotherapy with PD-L1-CAR-T cells or CCSC-DC vaccine only elicited moderate tumor remission both in vitro and in vivo. However, combination therapy markedly killed cancer cells and relieved the tumor burden in mice. Our findings may provide a novel strategy for the clinical treatment of colorectal malignancy.

4.
Sci Total Environ ; 756: 144139, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33280874

RESUMO

Constructing highly efficient metal-free material towards peroxymonosulfate (PMS) activation under photocatalytic assistance is a promising strategy for water decontamination. Herein, N vacancy modified g-C3N4 nanotube (VCN) was prepared to build a novel photo-assisted PMS activation system (PPAS), in which the unique electronic structure created by N vacancy could favor the PMS activation on VCN under visible-light irradiation. The role of N vacancy in PPAS was firstly studied through tuning its content in VCN. The results showed that the N vacancy greatly improved PMS activation on VCN PPAS towards organic pollutants removal. The VCN PPAS with moderate N vacancy modification performed best, whose kinetic constant for Rhodamine B degradation was 9.6 and 2.6 times higher than that of VCN/PMS system and pristine g-C3N4 PPAS, respectively. Moreover, the VCN PPAS performed well in wide pH range (3-12) and real water background. Selective removal of different organic pollutants was found on VCN PPAS, owing to the different interaction between pollutant and the catalyst surface with surface-bound radicals. The O2- and OH were major oxidants for pollutant removal in VCN PPAS, which were produced on dual active sites of VCN via two pathways: The N vacancy enhanced PMS adsorption and trapped photogenerated electrons for PMS reduction into OH, while the electron-deficient C atoms created by N loss promoted the PMS oxidation into O2-.

5.
J Colloid Interface Sci ; 560: 59-68, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31639565

RESUMO

Membrane filtration is an effective method for eliminating contaminants from water, but its performance is restricted by the trade-off between permeability and selectivity, as well as the serious membrane fouling. In this work, a novel porous carbon membrane (PCM) was constructed by coating porous carbon derived from metal-organic frameworks on ceramic membrane support. The PCM possessed good electrical conductivity, large surface area and hierarchical porous structure, making it promising to couple membrane filtration with electrochemistry for improved water treatment. Under electrochemical assistance, the PCM displayed enhanced selectivity and antifouling capability towards the water treatment. At -1.5 V, the PCM showed enhanced removal and reduced flux loss for the removal of suspended particles with size comparable to membrane pore size. Moreover, the PCM under +1.5 V exhibited effective removal of the organic chemicals unfavorable for size-exclusion by the membrane, whose removal efficiencies towards phenol and methyl orange were 3.0 and 3.3 times higher than those without voltage supply, respectively. The PCM with electrochemical assistance also displayed superior performance than PCM alone in real water treatment. The outstanding performance of the PCM under electrochemical assistance was mainly owing to its large electro-active surface area and enhanced mass transfer rate.

7.
Chemosphere ; 241: 125021, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683448

RESUMO

The magnetic composite CoFe2O4/ZIF-8 based on metal organic framework (MOF) with high specific surface area and high activity was synthesized by solvothermal method. The prepared catalysts were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), vibration sample magnetometer (VSM) and N2 adsorption-desorption isotherms, respectively. After characterization, CoFe2O4/ZIF-8 was applied to heterogeneous activation of peroxymonosulfate (PMS) for degrading methylene blue (MB). The result showed that the 0.075-CoFe2O4/ZIF-8 sample had the excellent catalytic activity. After catalytic reaction for 60 min, the degradation efficiency of MB (20 mg/L) reached about 97.9% at room temperature of 20 °C. The quenching experiment and electron paramagnetic resonance (EPR) analysis indicated that SO4- and OH radicals were the main active species in MB degradation. Meanwhile, the possible MB degradation mechanism was proposed. After four catalytic cycles, the degradation efficiency of MB has not been greatly reduced, indicating the practical application potential of CoFe2O4/ZIF-8 in water pollution cleanup.


Assuntos
Cobalto/química , Corantes/química , Compostos Férricos/química , Estruturas Metalorgânicas/química , Peróxidos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Catálise , Compostos Férricos/síntese química , Magnetismo , Azul de Metileno/química
8.
Chemosphere ; 244: 125526, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31821928

RESUMO

Production of sulfate radical from peroxymonosulfate (PMS) activation by carbon-based catalysts is a promising strategy to degrade pollutants. However, the electron-transfer ability of carbon catalysts, which is critical in PMS activation, still needs to be improved. In this study, a novel photo-assisted PMS activation system (PPAS) was constructed on a nitrogen-doped graphene/TiO2 (NG/TiO2), in which the photogenerated electrons excited from TiO2 could be utilized by NG for enhanced PMS activation on it. Moreover, the N content was varied to firstly investigate the role of N doping on PPAS. Under photo-assistance, the NG/TiO2 displayed significantly enhanced PMS activation for removal of organic pollutants. 100% bisphenol A (BPA) can be removed within 1 h. The results show that the degradation kinetic constant of BPA by the NG/TiO2 PPAS was 24 times higher than that under PMS alone, and was 1.4 times higher than that of rGO/TiO2 PPAS. The singlet oxygen (1O2) and sulfate radical (SO4-) were the main reactive species in PPAS. The outstanding performance of NG/TiO2 system was ascribed to the two main reasons: on one hand, the N doping decreased the schottky barrier formed between NG and TiO2, which favored the electron transfer from TiO2 to NG. On the other hand, the N doping enhanced the adsorption and electron-transfer ability of NG towards PMS.


Assuntos
Poluentes Ambientais/química , Recuperação e Remediação Ambiental/métodos , Grafite/química , Compostos Orgânicos/química , Peróxidos/química , Adsorção , Compostos Benzidrílicos/química , Compostos de Boro/química , Elétrons , Cinética , Nitrogênio/química , Fenóis/química , Oxigênio Singlete/química , Sulfatos/química , Titânio/química
9.
Chin J Integr Med ; 25(3): 216-224, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29335857

RESUMO

OBJECTIVE: To investigate the mechanism of inflflammatory-mediated toll-like receptor 4 (TLR4)-p38 mitogen-activated protein kinase (p38 MAPK) pathway in Kupffer cells (KCs) of non-alcoholic steatohepatitis (NASH) rats and the intervention effect of soothing Gan (Liver) and invigorating Pi (Spleen) recipes on this pathway. METHODS: After 1 week of acclimatization, 120 Sprague-Dawley male rats were randomly divided into 8 groups using a random number table (n=15 per group): normal group, model group, low-dose Chaihu Shugan Powder (, CHSG) group (3.2 g/kg), high-dose CHSG group (9.6 g/kg), low-dose Shenling Baizhu Powder (, SLBZ) group (10 g/kg), high-dose SLBZ (30 g/kg) group, and low- and highdose integrated recipe (L-IR, H-IR) groups. All rats in the model and treatment groups were fed with a high-fat diet (HFD). The treatments were administrated by gastrogavage once daily and lasted for 26 weeks. The liver tissues were detected with hematoxylin-eosin (HE) and oil red O staining. Levels of liver lipids, serum lipids and transaminases were measured. KCs were isolated from the livers of rats to evaluate the mRNA expressions of TLR4 and p38 MAPK by real-time flfluorescence quantitative polymerase chain reaction, and proteins expressions of TLR4, p-p38 MAPK and p38 MAPK by Western blot. Levels of inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin (IL)-1 and IL-6 in KCs were measured by enzyme-linked immunosorbent assay. RESULTS: After 26 weeks of HFD feeding, HE and oil red O staining showed that the NASH model rats successfully reproduced typical pathogenesis and histopathological features. Compared with the normal group, the model group exhibited significant increases in body weight, liver weight, liver index, serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol, and aspartate aminotransferase as well as TC and TG levels in liver tissues, and significant decrease in serum level of high-density lipoprotein cholesterol (Plt;0.05 or Plt;0.01), while those indices were significantly ameliorated in the H-IR group (Plt;0.05 or Plt;0.01). Higher levels of TNF-α, IL-1 and IL-6 in KCs were observed in the model group compared with the normal group (Plt;0.01). Significant decreases in TNF-α, IL-1 and IL-6 were observed in the H-SLBZ, H-IR and L-IR groups compared with the model group (Plt;0.05 or Plt;0.01). The mRNA expressions of TLR4 and p38 MAPK and protein expressions of TLR4, p38 MAPK and p-p38 MAPK in KCs in the model group were significantly higher than the normal group (Plt;0.01), while those expression levels in the L-IR and H-IR groups were significantly lower than the model group (Plt;0.05 or Plt;0.01). CONCLUSION: Inflflammation in KCs might play an important role in the pathogenesis of NASH in rats. The data demonstrated the importance of TLR4-p38MAPK signaling pathway in KCs for the anti-inflflammatory effect of soothing Gan and invigorating Pi recipes.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Macrófagos do Fígado/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Medicina Tradicional Chinesa , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Animais , Macrófagos do Fígado/fisiologia , Masculino , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Ratos , Ratos Sprague-Dawley
10.
J Hazard Mater ; 353: 401-409, 2018 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-29702455

RESUMO

Recently cobalt-based heterogeneous catalysts have been widely investigated for peroxymonosulfate (PMS) activation in sulfate radical-based advanced oxidation processes. However, the improvement of the catalytic performance for PMS activation remains to be a challenge. As the limiting step, the rapid transformation of CoII/CoIII redox pairs is crucial for PMS activation. Perovskites attract increasing attention due to their controllable oxidation state of B-site metal and formation of oxygen vacancies, which accelerates the cycle of redox pairs. LaCo1-xMxO3 (M = Cu, Fe and Mn) perovskites as heterogeneous catalysts of PMS were synthesized for the degradation of phenol. The results showed that LaCo0.4Cu0.6O3 exhibited the highest catalytic activity. The pseudo first-order kinetic constant of phenol degradation on LaCo0.4Cu0.6O3 is 0.302 min-1, being about 5 times as high as Co2+ with same molar concentration of cobalt in LaCo0.4Cu0.6O3. XPS analysis confirmed that substitution of copper could promote the cycle of CoII/CoIII, thus enhance the catalytic efficiency for PMS activation. The facilitated cycle of CoII/CoIII played a crucial role in the generation of sulfate radicals, hydroxyl radicals and singlet oxygen. And sulfate radical was the primary radical responsible for pollutants degradation. The results provide insights into constructing novel perovskite catalysts for the removal of organic pollutants in water.

11.
J Tradit Chin Med ; 38(4): 535-547, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32186078

RESUMO

OBJECTIVE: To investigate effects of the extracts from soothing-liver and invigorating-spleen formulas on the injury due to oxidative stress, mediated by the Nuclear factor-like 2 (Nrf2)-Antioxidant response element (ARE) pathway, in the hepatocytes of rats with non-alcoholic fatty liver disease (NAFLD) induced by high-fat diet. METHODS: Soothing-liver and invigorating-spleen formula mixtures were prepared for five groups: normal, model, soothing-liver formula group (SLG), invigorating-spleen formula group (ISG), integrated formula group (IG). The rat model of NAFLD was induced by feeding rats a high-fat diet (HFD). After 16 weeks, the hepatic tissue was examined following Haematoxylin-Eosin (H&E) staining and with Transmission electron microscopy (TEM). Levels of hepatic lipids, serum lipids and hepatic functions were measured using a biochemical analyser. Hepatocytes were isolated from the livers of rats and were identified by cellar immunohistochemistry, cellular immunofluorescence and flow cytometry. The expression levels of Nrf2, Kelch-like epichlorohydrin-associated protein 1 (Keap-1), haeme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) mRNAs were assessed by real-time fluorescence quantitative PCR. Nrf2, Keap-1, HO-1 and NQO1 proteins were measured by Western blotting. Finally, the levels of oxidative stress factors Superoxide Dismutase (SOD), malonaldehyde (MDA) and Glutathione peroxidase (GSH-Px) in hepatocytes were measured by WST-1, TBA and colorimetry. RESULTS: The H & E and TEM results showed that the NAFLD model rats successfully reproduced typical pathogenetic and histopathological features. The liver function and levels of hepatic lipids and serum lipids from the model rats were dramatically increased. Compared with the model group, the levels of hepatic lipids, serum lipids and hepatic function in the treatment groups were ameliorated to different degrees. The yields of purified hepatocytes in each rat were 4-5 ¡Á 108. The viability of the isolated hepatocytes was higher than 95%, with a purity over 93.2%. Cellular immunohistochemistry analysis showed that the hepatocytes were brown, while in the cellular immunofluorescence analysis, the hepatocytes showed green fluorescence. The expression levels of Nrf2, Keap-1, HO-1 and NQO1 mRNA and protein in the hepatocytes were significantly higher in the model group than in the normal group (P < 0.05, P < 0.01). Compared with the model group, the expression of Nrf2, Keap-1, HO-1 and NQO-1 mRNAs and proteins in all treatment groups increased, especially in the IG (P < 0.01). CONCLUSION: The extracts from soothing-liver and invigorating-spleen formulas may protect the liver against the injury induced by oxidative stress in hepatocytes by influencing the Nrf2-ARE pathway, which may be the mechanism having the potential for prevention and treatment of NAFLD.

12.
Artigo em Chinês | MEDLINE | ID: mdl-27255033

RESUMO

OBJECTIVE: To explore a new method of establishing HepG2 cell model of steatosis and observe the expression and significance of nuclear factor erythroid-2p45-related factor 2(Nrf2)/antioxidative response element (ARE) pathway related factors in HepG2 cells of steatosis. METHODS: HepG2 cells were induced with DMEM containing 25% fetal bovine serum, 0.1% MCT/LCT Fat Emulsion and 0.1 mmol/L free fatty acid (FFA) at different stages and the control group cells were cultured with normal DMEM medium. After the cell models were successfully established, lipid droplets in cytoplasm were observed with Oil Red 0 staining, and the triglyceride (TG) accumulation in HepG2 cells were tested by biochemical assay. Intracellular reactive oxygen species (ROS) concentration were detected by flow cytometry. Nitric oxide (NO), superoxide dismutase(SOD), malonyldialdehyde(MDA) and glutathione peroxidase(GSH-Px) were tested by biological reagent kit, while the protein expression of nuclear factor erythroid-2p45-related factor 2(Nrf2), heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase-1(NQO1) were analyzed by Western blot. RESULTS: Compared with that in the control group, red cytoplasmic lipid droplets were visible in model group; TG,ROS, NO, MDA concentration (P < 0.05, P < 0.01) and the protein expression of Nrf2, HO-1 and NQO1 (P < 0.05, P < 0.01)were significantly higher in model group, while SOD, GSH-Px concentration reduced significantly (P < 0.01). CONCLUSION: The in vitro cell model of steatosis and oxidative stress was successfully established. The activation of Nrf2/ARE pathway related factors maybe relevant to the overreaction of oxidative stress in HepG2 cells of steatosis.


Assuntos
Elementos de Resposta Antioxidante , Fígado Gorduroso/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Meios de Cultura , Ácidos Graxos não Esterificados , Fator de Transcrição de Proteínas de Ligação GA , Glutationa Peroxidase/metabolismo , Heme Oxigenase-1/metabolismo , Células Hep G2 , Humanos , Malondialdeído/metabolismo , NAD(P)H Desidrogenase (Quinona)/metabolismo , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Triglicerídeos/metabolismo
13.
Front Plant Sci ; 7: 313, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27014330

RESUMO

A suitable reference gene is an important prerequisite for guarantying accurate and reliable results in qPCR analysis. Celery is one of the representative vegetable in Apiaceae and is widely cultivated and consumed in the world. However, no reports have been previously published concerning reference genes in celery. In this study, the expression stabilities of nine candidate reference genes in leaf blade and petiole at different development stages were evaluated using three statistics algorithms geNorm, NormFinder, and BestKeeper. Our results showed that TUB-B, TUB-A, and UBC were the most reference genes among all tested samples. GAPDH represented the maximum stability for most individual sample, while the UBQ displayed the minimum stability. To further validate the stability of reference genes, the expression pattern of AgAP2-2 was calculated by using the selected genes for normalization. In addition, the expression patterns of several development-related genes were studied using the selected reference gene. Our results will be beneficial for further studies on gene transcription in celery.

14.
Artigo em Inglês | MEDLINE | ID: mdl-26504479

RESUMO

This study investigates the effect of soothing liver and invigorating spleen recipes on steatohepatitis examining the IKKß-NF-κB signaling pathway in KCs of NASH rats. SD male rats were randomly divided into 8 groups, and the NASH model was induced by a high-fat diet (HFD). After 26 weeks, liver tissue was examined in H&E stained sections and liver function was monitored biochemically. KCs were isolated by Seglen's method, with some modifications. The mRNA and protein expression of the IKKß-NF-κB signaling pathway components was examined by quantitative PCR and Western blotting. The results show that the high-fat diet induced NASH in the rats, and the soothing liver recipe and invigorating spleen recipe decreased the levels of TNF-α, IL-1, and IL-6 in KCs, as well as inhibiting the mRNA and protein expression of the IKKß-NF-κB signaling pathway components. In conclusion, the experiment indicated the importance of the IKKß-NF-κB signaling pathway in KCs for the anti-inflammatory effects of the soothing liver and invigorating spleen recipes.

15.
J Hazard Mater ; 299: 27-34, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26073518

RESUMO

Coupling membrane filtration with photocatalysis provides multifunction involving filtration and photocatalytic degradation for removing pollutants from water, but the performance of photocatalytic membrane is limited due to the quick recombination of photogenerated electron-holes in photocatalytic layer. Herein, a TiO2/carbon/Al2O3 membrane was designed and constructed through sequentially depositing graphitic carbon layer with good electro-conductivity and TiO2 nanoparticles layer with photocatalytic activity on Al2O3 membrane support. When light irradiated on the membrane with a voltage supply, the photogenerated electrons could be drained from photocatalytic layer and separated with holes efficiently, thus endowing the membrane with photoelectrocatalytic function. Membrane performance tests indicated that the photoelectrocatalytic membrane filtration (PECM) showed improved removal of natural organic matters (NOMs) and permeate flux with increasing voltage supply. For PECM process at 1.0 V, its NOMs removal was 1.2 or 1.7 times higher than that of filtration with UV irradiation or filtration alone, and its stable permeate flux was 1.3 or 3 times higher than that of filtration with UV irradiation or filtration alone. Moreover, the PECM process exhibited special advantage in removing organic chemicals (e.g., Rhodamine B), which displayed 1.3 or 3 times higher removal than that of filtration with UV irradiation or filtration alone.

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