In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton a...In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.展开更多
AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders ...AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders oxidative stress, and the protective effect of L-carnitine(a nutrient involved in fatty acid metabolism and the control of the oxidative process), was assessed by monitoring various parameters related to the oxidative stress, autophagy and cell death. RESULTS Associated with its physiological function, a muscle cell metabolism is highly dependent on oxygen and may produce reactive oxygen species(ROS), especially under pathological conditions. High levels of ROS are known to induce injuries in cell structure as they interact at many levels in cell function. In C2C12 cells, a treatment with menadione induced a loss of transmembrane mitochondrial potential, an increase in mitochondrial production of ROS; it also induces autophagy and was able to provoke cell death. Pre-treatment of the cells with L-carnitine reduced ROS production, diminished autophagy and protected C2C12 cells against menadione-induced deleterious effects. CONCLUSION In conclusion, L-carnitine limits the oxidative stress in these cells and prevents cell death.展开更多
Background The immunomodulatory effects of glucocorticoids （GCs） have been described as bimodal. High concentration of GCs exerts immunosuppressive effects and low levels of GCs are immunopermissive. While the immun...Background The immunomodulatory effects of glucocorticoids （GCs） have been described as bimodal. High concentration of GCs exerts immunosuppressive effects and low levels of GCs are immunopermissive. While the immunosuppressive mechanisms of GCs have been investigated intensely, the immunopermissive effects of GCs remain unclear. A lot of studies showed GCs could exert rapid non-genomic actions. We herein studied the rapid immunopromoting effects of GCs.Methods We observed the rapid （within 30 minutes） effects of corticosterone on respiratory burst of mouse peritoneal macrophages and studied their mechanisms. The superoxide anions were measured by cytochrome C reduction assay.Protein kinase C phosphorylation was measured by Western blotting and membrane fluidity was evaluated by fluorescence polarization measurement.Results The 10-8 mol/L and 10-7 mol/L corticosterone rapidly increased the superoxide anions production by macrophages, which were insensitive to GC-receptor antagonist, mifepristone, and protein-synthesis inhibitor,cycloheximide. Corticosterone coupled to bovine serum albumin was able to mimic the effects of corticosterone. The effects were independent of protein kinase C pathway and the change in membrane fluidity.Conclusions The results indicate that corticosterone rapidly promote the superoxide anions production by mouse peritoneal macrophages may through non-genomic mechanisms. This study may contribute to understanding the effects of GCs under stress condition and the physiological significance of nongenomic effects of GCs.展开更多
Recently,a study of mimic enzyme has received more attentions.However,the investigation on the oxidoreductase activity of electron mediators in the biological respiratory chain is still rare.Herein,we found that cadmi...Recently,a study of mimic enzyme has received more attentions.However,the investigation on the oxidoreductase activity of electron mediators in the biological respiratory chain is still rare.Herein,we found that cadmium sulfide(CdS)nanorods can catalyze the formation of superoxide anions.Due to the role of the photo-generated holes and the nicotinamide adenine dinucleotide(NADH)oxidation promoted by superoxide anion(O_(2)^(•−)),the CdS exhibits NADH oxidase-like activity and can be coupled with dehydrogenase to realize the recycling of NADH.It is worth mentioning that the bio-electron acceptor,cytochrome c(Cyt c),as a chromogenic substrate,can accept electrons transferred from O_(2)^(•−),which demonstrates the Cyt c reductase-like activity of CdS under physiological pH conditions.For different substrates,O_(2)^(•−)induced from CdS show oxidizing capacity for NADH and reducing capacity for Cyt c,which provides a new perspective for the in-depth study of new nanozyme.展开更多
基金supported by the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (No.2017BT01Z032)the National Natural Science Foundation of China (No.21577027)。
文摘In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.
基金the Association Francaise contre les Myopathies for financial support
文摘AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders oxidative stress, and the protective effect of L-carnitine(a nutrient involved in fatty acid metabolism and the control of the oxidative process), was assessed by monitoring various parameters related to the oxidative stress, autophagy and cell death. RESULTS Associated with its physiological function, a muscle cell metabolism is highly dependent on oxygen and may produce reactive oxygen species(ROS), especially under pathological conditions. High levels of ROS are known to induce injuries in cell structure as they interact at many levels in cell function. In C2C12 cells, a treatment with menadione induced a loss of transmembrane mitochondrial potential, an increase in mitochondrial production of ROS; it also induces autophagy and was able to provoke cell death. Pre-treatment of the cells with L-carnitine reduced ROS production, diminished autophagy and protected C2C12 cells against menadione-induced deleterious effects. CONCLUSION In conclusion, L-carnitine limits the oxidative stress in these cells and prevents cell death.
基金This work was supported by grants from the Military Twelfth Five-Year Plan and National Natural Science Foundation of China （No. 30873077, No. 30971083） The authors declared no conflicts of interests.
文摘Background The immunomodulatory effects of glucocorticoids （GCs） have been described as bimodal. High concentration of GCs exerts immunosuppressive effects and low levels of GCs are immunopermissive. While the immunosuppressive mechanisms of GCs have been investigated intensely, the immunopermissive effects of GCs remain unclear. A lot of studies showed GCs could exert rapid non-genomic actions. We herein studied the rapid immunopromoting effects of GCs.Methods We observed the rapid （within 30 minutes） effects of corticosterone on respiratory burst of mouse peritoneal macrophages and studied their mechanisms. The superoxide anions were measured by cytochrome C reduction assay.Protein kinase C phosphorylation was measured by Western blotting and membrane fluidity was evaluated by fluorescence polarization measurement.Results The 10-8 mol/L and 10-7 mol/L corticosterone rapidly increased the superoxide anions production by macrophages, which were insensitive to GC-receptor antagonist, mifepristone, and protein-synthesis inhibitor,cycloheximide. Corticosterone coupled to bovine serum albumin was able to mimic the effects of corticosterone. The effects were independent of protein kinase C pathway and the change in membrane fluidity.Conclusions The results indicate that corticosterone rapidly promote the superoxide anions production by mouse peritoneal macrophages may through non-genomic mechanisms. This study may contribute to understanding the effects of GCs under stress condition and the physiological significance of nongenomic effects of GCs.
基金supported by the National Key R&D Program of China(No.2019YFA0709202)MOST China(No.2016YFA0203200)+1 种基金the International Cooperation Project of Jilin Scientific and Technological Development Program(No.20190701059GH)the National Natural Science Foundation of China(Nos.21721003 and 31301177).
文摘Recently,a study of mimic enzyme has received more attentions.However,the investigation on the oxidoreductase activity of electron mediators in the biological respiratory chain is still rare.Herein,we found that cadmium sulfide(CdS)nanorods can catalyze the formation of superoxide anions.Due to the role of the photo-generated holes and the nicotinamide adenine dinucleotide(NADH)oxidation promoted by superoxide anion(O_(2)^(•−)),the CdS exhibits NADH oxidase-like activity and can be coupled with dehydrogenase to realize the recycling of NADH.It is worth mentioning that the bio-electron acceptor,cytochrome c(Cyt c),as a chromogenic substrate,can accept electrons transferred from O_(2)^(•−),which demonstrates the Cyt c reductase-like activity of CdS under physiological pH conditions.For different substrates,O_(2)^(•−)induced from CdS show oxidizing capacity for NADH and reducing capacity for Cyt c,which provides a new perspective for the in-depth study of new nanozyme.
