Rationale:Multi-organ failure is a symptom of paraquat poisoning,resulting in high mortality and morbidity rates.Though paraquat is widely available,poisoning through inhalation is rare.Patient’s Concern:A 37-year-ol...Rationale:Multi-organ failure is a symptom of paraquat poisoning,resulting in high mortality and morbidity rates.Though paraquat is widely available,poisoning through inhalation is rare.Patient’s Concern:A 37-year-old male reported to the emergency department with complaints of vomiting after an alleged history of inhalation of paraquat while at work.Diagnosis:Paraquat poisoning.Interventions:Supportive management along with multiple sessions of hemodialysis.Outcomes:Renal complications caused by paraquat were improved after multiple sessions of hemodialysis.However,the patient developed respiratory complications and later due to persistent hypoxemia and non-responsive to supportive therapy,he succumbed to his illness.Lessons:Acute kidney injury is a complication of paraquat poisoning.However,kidney involvement with the inhalational mode is rare.It is caused by reduction and oxidation cycles,as well as the formation of reactive oxygen species,necessitating hemodialysis as the treatment.Without a clear history,a specific clinical trait,or a diagnostic test,diagnosis can be difficult.Our case thus highlights the inhaled paraquat poisoning,presenting with acute kidney injury with late respiratory impairment as a consequence.展开更多
BACKGROUND:Pulmonary fibrosis(PF)is one of the main causes of death in patients with paraquat(PQ)poisoning.This study aimed to evaluate the relationship between mitochondrial fi ssion and oxidative stress in PQ-induce...BACKGROUND:Pulmonary fibrosis(PF)is one of the main causes of death in patients with paraquat(PQ)poisoning.This study aimed to evaluate the relationship between mitochondrial fi ssion and oxidative stress in PQ-induced epithelial-mesenchymal transition(EMT)and PF.METHODS:C57BL/6 mice and MLE-12 cells were exposed to PQ to construct a PF model in vivo and in vitro.Histological changes in the lungs were examined by hematoxylin and eosin(H&E)staining.Mitochondrial morphology was detected by MitoTracker®Deep Red FM or transmission electron microscopy(TEM).Western blotting and immunofluorescence were used to determine the expression of protein.The migration ability of the cells was detected by the cell scratch test.Mitochondrial DNA(mtDNA)levels were assessed by real-time polymerase chain reaction(PCR).Enzyme-linked immunosorbent assay(ELISA)was applied to detect cytokine levels.Superoxide dismutase(SOD)activity and the levels of glutathione(GSH)and malondialdehyde(MDA)were detected by chemichromatometry.RESULTS:PQ exposure caused EMT and PF in vivo and in vitro.PQ destroyed mitochondrial structure and enhanced the expression of dynamin-related protein 1(Drp1),which were accompanied by oxidative stress.Inhibiting mitochondrial fission using mitochondrial division inhibitor-1(Mdivi-1),a selective inhibitor of Drp1,attenuated PQ-induced EMT and oxidative damage.Treatment with N-acetyl-L-cysteine(NAC),an antioxidant,reduced Drp1 expression,attenuated mitochondrial structure damage and inhibited PQ-induced EMT and PF.Both Mdivi-1 and NAC treatment markedly suppressed mtDNA release,the expression of Toll-like receptor 9(TLR9)and phosphorylation(P)-NF-κB p65 as well as cytokines(interleukin 6[IL-6],interleukin-1β[IL-1β],and tumor necrosis factor-α[TNF-α])production.CONCLUSION:Mutual promotion of mitochondrial fission and oxidative stress contributes to EMT in PQ-induced PF,which is associated with the mtDNA/TLR9/NF-κB pathway.展开更多
Phytosanitary products are frequently used by agriculture worldwide and in Cameroon in particular;this with a view to protecting crops and improving agricultural yields (Riba and Silvy, 1989;Bonny, 1996;Mattews et al....Phytosanitary products are frequently used by agriculture worldwide and in Cameroon in particular;this with a view to protecting crops and improving agricultural yields (Riba and Silvy, 1989;Bonny, 1996;Mattews et al., 2003). There are many studies on the retention of pesticides by soils, but in Cameroon, very few studies have focused on the interaction between andosols, ferralsols and the pesticides paraquat and carbendazim, which are widely used by farmers in Foumbot and Ebolowa. The objective of this work is to provide elements of understanding on the mobility of paraquat along the profile of andosolic soils of Foumbot and ferralitic soils of Ebolowa during which the soil samples were collected. The soil samples were characterized by the analytical method in accordance with the international standards at the Research Unit of Soil Analysis and Environmental Chemistry of the University of Dschang, as recommended by Pauwels et al. (1992). The different analyses of the soil samples were carried out according to the classical procedures of the Faculty of Agronomy and Agricultural Sciences, Soil, Plant and Water Laboratory. Statistical analysis was performed. Pearson correlation tests were performed to correlate soil physicochemical properties with soil adsorption parameters;thus, it has been observed that there is a strong correlation between the CEC and the rate of organic matter. The experimental device used for this study is a block device. This study was carried out in batch mode and by varying the contact time, the pH of the solution, the mass of the soil, the concentration of the solution. The physicochemical characterizations of the soils were studied. The mineralogical analysis was carried out by X-ray and infrared diffraction. The analysis of the samples was carried out by UV-Vis absorption spectrometry. The study of the adsorption kinetics showed that the adsorption of paraquat by the soils of Foumbot NK1, NK3 and Ebolowa MIN1 is better described by the pseudo-second order kinetic model since the q<sub>e</sub> values obtained from this model are close to the experimental values. The study of the adsorption kinetics showed that the adsorption process is very fast during the first thirty minutes and medium to very slow afterwards. The half-reaction times indicate that the kinetics of pollutant accumulation is faster on the surface of fallow soil NK1 (t1/2 = 11.30 min.), followed by cultivated soil NK3 (t1/2 = 19.94 min.) and finally the bare ground of Ebolowa MIN1 (t1/2 = 264.05 min.). Three adsorption models have been studied and the isotherms are best described by the Freundlich and Dubinin-Radushkevitch model. The adsorption of paraquat by the andosolic soils of Foumbot and the ferralitic soils of Ebolowa is best described by the Freundlich model. Bare forest soil MIN1 with a depth of 25 to 50 cm better describes adsorption with a correlation coefficient R<sup>2</sup> = 0.951 μmol/g compared to cultivated soil NK3 with a surface layer of 0 to 25 cm and finally fallows soil NK1 with a depth of 25 to 50 cm. The strong biological activity of the 25 to 50 cm deep layer of MIN1, the C/N ratio of 11.00 testifies to a good mineralization of this soil. The clay content of 45% would promote the retention of paraquat and reduce the presence of this pesticide at depth.展开更多
Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic(PV)grid-connected systems diversified.This research aims to produce a high-performance inverter with a fast d...Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic(PV)grid-connected systems diversified.This research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total har-monic distortion(THD)even under nonlinear load applications by improving its control scheme.The proposed system is expected to operate in both stand-alone mode and grid-connected mode.In stand-alone mode,the proposed controller supplies power to critical loads,alternatively during grid-connected mode provide excess energy to the utility.A modified variable step incremental conductance(VS-InCond)algorithm is designed to extract maximum power from PV.Whereas the proposed inverter controller is achieved by using a modified PQ theory with double-band hysteresis current controller(PQ-DBHCC)to produce a reference current based on a decomposition of a single-phase load current.The nonlinear rectifier loads often create significant distortion in the output voltage of single-phase inverters,due to excessive current harmonics in the grid.Therefore,the proposed method generates a close-loop reference current for the switching scheme,hence,minimizing the inverter voltage distortion caused by the excessive grid current harmonics.The simulation findings suggest the proposed control technique can effectively yield more than 97%of power conversion efficiency while suppressing the grid current THD by less than 2%and maintaining the unity power factor at the grid side.The efficacy of the proposed controller is simulated using MATLAB/Simulink.展开更多
随着逆变型分布式电源(inverter interfaced distributed generation,IIDG)在配电网中的渗透率不断提高,且在新的故障穿越行为要求下,现有的故障分析方法已不再适用。为此,提出一种适应于最新并网规定的含PQ控制IIDG的配电网故障分析方...随着逆变型分布式电源(inverter interfaced distributed generation,IIDG)在配电网中的渗透率不断提高,且在新的故障穿越行为要求下,现有的故障分析方法已不再适用。为此,提出一种适应于最新并网规定的含PQ控制IIDG的配电网故障分析方法。该方法首先通过分析IIDG故障电流特性,提出计及控制特性的IIDG压控电流源等值模型;在此基础上,建立了故障下的含IIDG配电网节点电压方程,并针对不同IIDG间相互耦合以及公共连接点(point of common coupling,PCC)故障电压与IIDG故障电流之间存在非线性关系,提出相应的迭代修正求解方法。最后,通过算例仿真计算,验证了所提方法的可行性和有效性。展开更多
文摘Rationale:Multi-organ failure is a symptom of paraquat poisoning,resulting in high mortality and morbidity rates.Though paraquat is widely available,poisoning through inhalation is rare.Patient’s Concern:A 37-year-old male reported to the emergency department with complaints of vomiting after an alleged history of inhalation of paraquat while at work.Diagnosis:Paraquat poisoning.Interventions:Supportive management along with multiple sessions of hemodialysis.Outcomes:Renal complications caused by paraquat were improved after multiple sessions of hemodialysis.However,the patient developed respiratory complications and later due to persistent hypoxemia and non-responsive to supportive therapy,he succumbed to his illness.Lessons:Acute kidney injury is a complication of paraquat poisoning.However,kidney involvement with the inhalational mode is rare.It is caused by reduction and oxidation cycles,as well as the formation of reactive oxygen species,necessitating hemodialysis as the treatment.Without a clear history,a specific clinical trait,or a diagnostic test,diagnosis can be difficult.Our case thus highlights the inhaled paraquat poisoning,presenting with acute kidney injury with late respiratory impairment as a consequence.
基金supported by the Wenzhou Municipal Science and Technology Bureau(Y2020092)partly by the Key Specialty of Traditional Chinese Medicine of Zhejiang Province in the 13th Five-Year Plan period(Emergency Department).
文摘BACKGROUND:Pulmonary fibrosis(PF)is one of the main causes of death in patients with paraquat(PQ)poisoning.This study aimed to evaluate the relationship between mitochondrial fi ssion and oxidative stress in PQ-induced epithelial-mesenchymal transition(EMT)and PF.METHODS:C57BL/6 mice and MLE-12 cells were exposed to PQ to construct a PF model in vivo and in vitro.Histological changes in the lungs were examined by hematoxylin and eosin(H&E)staining.Mitochondrial morphology was detected by MitoTracker®Deep Red FM or transmission electron microscopy(TEM).Western blotting and immunofluorescence were used to determine the expression of protein.The migration ability of the cells was detected by the cell scratch test.Mitochondrial DNA(mtDNA)levels were assessed by real-time polymerase chain reaction(PCR).Enzyme-linked immunosorbent assay(ELISA)was applied to detect cytokine levels.Superoxide dismutase(SOD)activity and the levels of glutathione(GSH)and malondialdehyde(MDA)were detected by chemichromatometry.RESULTS:PQ exposure caused EMT and PF in vivo and in vitro.PQ destroyed mitochondrial structure and enhanced the expression of dynamin-related protein 1(Drp1),which were accompanied by oxidative stress.Inhibiting mitochondrial fission using mitochondrial division inhibitor-1(Mdivi-1),a selective inhibitor of Drp1,attenuated PQ-induced EMT and oxidative damage.Treatment with N-acetyl-L-cysteine(NAC),an antioxidant,reduced Drp1 expression,attenuated mitochondrial structure damage and inhibited PQ-induced EMT and PF.Both Mdivi-1 and NAC treatment markedly suppressed mtDNA release,the expression of Toll-like receptor 9(TLR9)and phosphorylation(P)-NF-κB p65 as well as cytokines(interleukin 6[IL-6],interleukin-1β[IL-1β],and tumor necrosis factor-α[TNF-α])production.CONCLUSION:Mutual promotion of mitochondrial fission and oxidative stress contributes to EMT in PQ-induced PF,which is associated with the mtDNA/TLR9/NF-κB pathway.
文摘Phytosanitary products are frequently used by agriculture worldwide and in Cameroon in particular;this with a view to protecting crops and improving agricultural yields (Riba and Silvy, 1989;Bonny, 1996;Mattews et al., 2003). There are many studies on the retention of pesticides by soils, but in Cameroon, very few studies have focused on the interaction between andosols, ferralsols and the pesticides paraquat and carbendazim, which are widely used by farmers in Foumbot and Ebolowa. The objective of this work is to provide elements of understanding on the mobility of paraquat along the profile of andosolic soils of Foumbot and ferralitic soils of Ebolowa during which the soil samples were collected. The soil samples were characterized by the analytical method in accordance with the international standards at the Research Unit of Soil Analysis and Environmental Chemistry of the University of Dschang, as recommended by Pauwels et al. (1992). The different analyses of the soil samples were carried out according to the classical procedures of the Faculty of Agronomy and Agricultural Sciences, Soil, Plant and Water Laboratory. Statistical analysis was performed. Pearson correlation tests were performed to correlate soil physicochemical properties with soil adsorption parameters;thus, it has been observed that there is a strong correlation between the CEC and the rate of organic matter. The experimental device used for this study is a block device. This study was carried out in batch mode and by varying the contact time, the pH of the solution, the mass of the soil, the concentration of the solution. The physicochemical characterizations of the soils were studied. The mineralogical analysis was carried out by X-ray and infrared diffraction. The analysis of the samples was carried out by UV-Vis absorption spectrometry. The study of the adsorption kinetics showed that the adsorption of paraquat by the soils of Foumbot NK1, NK3 and Ebolowa MIN1 is better described by the pseudo-second order kinetic model since the q<sub>e</sub> values obtained from this model are close to the experimental values. The study of the adsorption kinetics showed that the adsorption process is very fast during the first thirty minutes and medium to very slow afterwards. The half-reaction times indicate that the kinetics of pollutant accumulation is faster on the surface of fallow soil NK1 (t1/2 = 11.30 min.), followed by cultivated soil NK3 (t1/2 = 19.94 min.) and finally the bare ground of Ebolowa MIN1 (t1/2 = 264.05 min.). Three adsorption models have been studied and the isotherms are best described by the Freundlich and Dubinin-Radushkevitch model. The adsorption of paraquat by the andosolic soils of Foumbot and the ferralitic soils of Ebolowa is best described by the Freundlich model. Bare forest soil MIN1 with a depth of 25 to 50 cm better describes adsorption with a correlation coefficient R<sup>2</sup> = 0.951 μmol/g compared to cultivated soil NK3 with a surface layer of 0 to 25 cm and finally fallows soil NK1 with a depth of 25 to 50 cm. The strong biological activity of the 25 to 50 cm deep layer of MIN1, the C/N ratio of 11.00 testifies to a good mineralization of this soil. The clay content of 45% would promote the retention of paraquat and reduce the presence of this pesticide at depth.
基金funded by Geran Galakan Penyelidik Muda GGPM-2020-004 Universiti Kebangsaan Malaysia.
文摘Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic(PV)grid-connected systems diversified.This research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total har-monic distortion(THD)even under nonlinear load applications by improving its control scheme.The proposed system is expected to operate in both stand-alone mode and grid-connected mode.In stand-alone mode,the proposed controller supplies power to critical loads,alternatively during grid-connected mode provide excess energy to the utility.A modified variable step incremental conductance(VS-InCond)algorithm is designed to extract maximum power from PV.Whereas the proposed inverter controller is achieved by using a modified PQ theory with double-band hysteresis current controller(PQ-DBHCC)to produce a reference current based on a decomposition of a single-phase load current.The nonlinear rectifier loads often create significant distortion in the output voltage of single-phase inverters,due to excessive current harmonics in the grid.Therefore,the proposed method generates a close-loop reference current for the switching scheme,hence,minimizing the inverter voltage distortion caused by the excessive grid current harmonics.The simulation findings suggest the proposed control technique can effectively yield more than 97%of power conversion efficiency while suppressing the grid current THD by less than 2%and maintaining the unity power factor at the grid side.The efficacy of the proposed controller is simulated using MATLAB/Simulink.
文摘随着逆变型分布式电源(inverter interfaced distributed generation,IIDG)在配电网中的渗透率不断提高,且在新的故障穿越行为要求下,现有的故障分析方法已不再适用。为此,提出一种适应于最新并网规定的含PQ控制IIDG的配电网故障分析方法。该方法首先通过分析IIDG故障电流特性,提出计及控制特性的IIDG压控电流源等值模型;在此基础上,建立了故障下的含IIDG配电网节点电压方程,并针对不同IIDG间相互耦合以及公共连接点(point of common coupling,PCC)故障电压与IIDG故障电流之间存在非线性关系,提出相应的迭代修正求解方法。最后,通过算例仿真计算,验证了所提方法的可行性和有效性。
