Plants are sources of medicinal compounds,and they play a crucial role in human health maintenance.Abrus precatorius is one of the important medicinal plants that have been alleged for their medicinal properties.This ...Plants are sources of medicinal compounds,and they play a crucial role in human health maintenance.Abrus precatorius is one of the important medicinal plants that have been alleged for their medicinal properties.This research unraveled the pharmacological effect of ethanolic extract of Abrus precatorius on lipid peroxidation,liver parameters,and Na^(+)/K^(+)-ATPase activity in HgCl_(2) treated wistar rats.Twenty-four(24)albino wistar rats weighing between 150-200 g were distributed into four groups of 6 animals each.Group A(control)received normal saline(0.9% NaCl),group B received 400 mg/kg of the extract only,group C received 4 mg/kg HgCl_(2) only,and group D received 400 mg/kg of extract+4 mg/kg of HgCl_(2).The treatment lasted for two weeks,and the animals were sacrificed on the 15th day.The blood,brains and livers were collected and used for assay of lipid peroxidation,liver function,and sodium pump activity.The results of liver function test revealed an elevated(P<0.05)level of serum aspartate transaminase,alanine transaminase,alkaline phosphatase,and total bilirubin in the group that received HgCl_(2) only(group C)when compared with the normal control(group A)that received normal saline only.However,the administration of extract in group D led to a marked(P<0.05)reduction in the activities of these enzymes and the level of total bilirubin when compared to the negative control(group C).On the contrary,HgCl_(2) caused a significant(P<0.05)reduction in serum total protein and albumin levels,but the extract reversed the effect of HgCl_(2) by elevating their concentrations.Nonetheless,the effect elicited by this extract is comparable to group A which received normal saline.Moreso,the result of lipid peroxidation revealed that HgCl_(2) treatment caused a marked(P<0.05)increase in the formation of lipid peroxidation adducts in both liver and brain homogenates in group C.On the contrary,administration of Abrus precatorius extract profoundly(P<0.05)inhibited HgCl_(2)-induced lipid peroxidation in group D.In addition,HgCl_(2) inhibited the activity of cerebral Na^(+)/K^(+)-ATPase,but the extract restored normalcy by increasing the activity of the enzyme in group D.Consequently,the results obtained justify the traditional use of Abrus precatorius and suggest that Abrus precatorius leaves may be used for management of liver diseases,oxidative stress-linked diseases and some neurodegenerative ailments.展开更多
Elemental mercury （Hg^0） in flue gases can be efficiently captured by mercury chloride （HgCl2） solution. However, the absorption behaviors and the influencing effects are still poorly understood. The mechanism of ...Elemental mercury （Hg^0） in flue gases can be efficiently captured by mercury chloride （HgCl2） solution. However, the absorption behaviors and the influencing effects are still poorly understood. The mechanism of Hg^0 absorption by HgCl2 and the factors that control the removal were studied in this paper. It was found that when the mole ratio of Cl^- to HgCl2 is 10：1, the Hg^0 removal efficiency is the highest. Among the main mercury chloride species, HgCl3^- is the most efficient ion for Hg^0 removal in the HgCl2 absorption system when moderate concentrations of chloride ions exist. The Hg^0 absorption reactions in the aqueous phase were investigated computationaIIy using Moller-Plesset perturbation theory. The calculated Gibbs free energies and energy barriers are in excellent agreement with the results obtained from experiments. In the presence of SO3^2- and SO2, Hg^2＋ reduction occurred and Hg^0 removal efficiency decreased. The reduced Hg^0 removal can be controlled through increased chloride concentration to some degree. Low pH value in HgCla solution enhanced the Hg^0 removal efficiency, and the effect was more significant in dilute HgCl2 solutions. The presence of SO4^2- and NO3^- did not affect Hg^0 removal by HgCl2.展开更多
In order to investigate the effect of water channel blocker HgCl2 on the hydraulic resistance in roots of maize seedlings, a xylem pressure probe was used to monitor the changes in root xylem pressure in response to N...In order to investigate the effect of water channel blocker HgCl2 on the hydraulic resistance in roots of maize seedlings, a xylem pressure probe was used to monitor the changes in root xylem pressure in response to NaCl- or mannitol-induced osmotic stresses before and after the application of HgCl2. When the maize roots were subjected to 500 umol L-1 HgCl2 in root bathing solution, not only a considerable decline in xylem pressure （increase in xylem tension） was observed, but the loss of responsiveness of the plant to both salt- and mannitol-induced osmotic stresses in terms of xylem pressure change was seen as well when the transpiration rate of the plant was not significantly changed. The results are similar but different from the reversed osmosis by the Fenton reaction in the internodes of Chara coralline, showing that the mechanisms of water transport across cell membrane in plant roots are far more complicated than expected.展开更多
Experiments were conducted in a fixed-bed reactor containing a commercial V2O5/WO3/TiO2 catalyst to investigate mercury oxidation in the presence of HCl and O2. Mercury oxidation was improved significantly in the pres...Experiments were conducted in a fixed-bed reactor containing a commercial V2O5/WO3/TiO2 catalyst to investigate mercury oxidation in the presence of HCl and O2. Mercury oxidation was improved significantly in the presence of HCl and O2, and the Hg^0 oxidation efficiencies decreased slowly as the temperature increased from 200 to 400℃. Upon pretreatment with HCl and O2 at 350℃, the catalyst demonstrated higher catalytic activity for Hg^0 oxidation. Notably,the effect of pretreatment with HCl alone was not obvious. For the catalyst treated with HCl and O2, better performance was observed with lower reaction temperatures. The results showed that both HCl and Hg^0 were first adsorbed onto the catalyst and then reacted with O2 following its adsorption, which indicates that the oxidation of Hg^0 over the commercial catalyst followed the Langmuir–Hinshelwood mechanism. Several characterization techniques, including Hg^0temperature-programmed desorption（Hg-TPD） and X-ray photoelectron spectroscopy（XPS）, were employed in this work. Hg-TPD profiles showed that weakly adsorbed mercury species were converted to strongly bound species in the presence of HCl and O2. XPS patterns indicated that new chemisorbed oxygen species were formed by the adsorption of HCl, which consequently facilitated the oxidation of mercury.展开更多
文摘Plants are sources of medicinal compounds,and they play a crucial role in human health maintenance.Abrus precatorius is one of the important medicinal plants that have been alleged for their medicinal properties.This research unraveled the pharmacological effect of ethanolic extract of Abrus precatorius on lipid peroxidation,liver parameters,and Na^(+)/K^(+)-ATPase activity in HgCl_(2) treated wistar rats.Twenty-four(24)albino wistar rats weighing between 150-200 g were distributed into four groups of 6 animals each.Group A(control)received normal saline(0.9% NaCl),group B received 400 mg/kg of the extract only,group C received 4 mg/kg HgCl_(2) only,and group D received 400 mg/kg of extract+4 mg/kg of HgCl_(2).The treatment lasted for two weeks,and the animals were sacrificed on the 15th day.The blood,brains and livers were collected and used for assay of lipid peroxidation,liver function,and sodium pump activity.The results of liver function test revealed an elevated(P<0.05)level of serum aspartate transaminase,alanine transaminase,alkaline phosphatase,and total bilirubin in the group that received HgCl_(2) only(group C)when compared with the normal control(group A)that received normal saline only.However,the administration of extract in group D led to a marked(P<0.05)reduction in the activities of these enzymes and the level of total bilirubin when compared to the negative control(group C).On the contrary,HgCl_(2) caused a significant(P<0.05)reduction in serum total protein and albumin levels,but the extract reversed the effect of HgCl_(2) by elevating their concentrations.Nonetheless,the effect elicited by this extract is comparable to group A which received normal saline.Moreso,the result of lipid peroxidation revealed that HgCl_(2) treatment caused a marked(P<0.05)increase in the formation of lipid peroxidation adducts in both liver and brain homogenates in group C.On the contrary,administration of Abrus precatorius extract profoundly(P<0.05)inhibited HgCl_(2)-induced lipid peroxidation in group D.In addition,HgCl_(2) inhibited the activity of cerebral Na^(+)/K^(+)-ATPase,but the extract restored normalcy by increasing the activity of the enzyme in group D.Consequently,the results obtained justify the traditional use of Abrus precatorius and suggest that Abrus precatorius leaves may be used for management of liver diseases,oxidative stress-linked diseases and some neurodegenerative ailments.
基金supported by the Major State Basic Research Development Program (No. 2013CB430005)the National Natural Science Foundation of China (No. 51278294)the National High Technology Research and Development Program (No. 2012AA062504)
文摘Elemental mercury （Hg^0） in flue gases can be efficiently captured by mercury chloride （HgCl2） solution. However, the absorption behaviors and the influencing effects are still poorly understood. The mechanism of Hg^0 absorption by HgCl2 and the factors that control the removal were studied in this paper. It was found that when the mole ratio of Cl^- to HgCl2 is 10：1, the Hg^0 removal efficiency is the highest. Among the main mercury chloride species, HgCl3^- is the most efficient ion for Hg^0 removal in the HgCl2 absorption system when moderate concentrations of chloride ions exist. The Hg^0 absorption reactions in the aqueous phase were investigated computationaIIy using Moller-Plesset perturbation theory. The calculated Gibbs free energies and energy barriers are in excellent agreement with the results obtained from experiments. In the presence of SO3^2- and SO2, Hg^2＋ reduction occurred and Hg^0 removal efficiency decreased. The reduced Hg^0 removal can be controlled through increased chloride concentration to some degree. Low pH value in HgCla solution enhanced the Hg^0 removal efficiency, and the effect was more significant in dilute HgCl2 solutions. The presence of SO4^2- and NO3^- did not affect Hg^0 removal by HgCl2.
基金supported by the National Natural Science Foundation of China (30471044)
文摘In order to investigate the effect of water channel blocker HgCl2 on the hydraulic resistance in roots of maize seedlings, a xylem pressure probe was used to monitor the changes in root xylem pressure in response to NaCl- or mannitol-induced osmotic stresses before and after the application of HgCl2. When the maize roots were subjected to 500 umol L-1 HgCl2 in root bathing solution, not only a considerable decline in xylem pressure （increase in xylem tension） was observed, but the loss of responsiveness of the plant to both salt- and mannitol-induced osmotic stresses in terms of xylem pressure change was seen as well when the transpiration rate of the plant was not significantly changed. The results are similar but different from the reversed osmosis by the Fenton reaction in the internodes of Chara coralline, showing that the mechanisms of water transport across cell membrane in plant roots are far more complicated than expected.
基金supported by the National Basic Research Program(973)of China(No.2013CB430005)the Special Research Funding for Public Benefit Industries from National Ministry of Environmental Protection(No.201309018)the National Hi-Tech Research and Development Program(863)of China(No.2013AA065404)
文摘Experiments were conducted in a fixed-bed reactor containing a commercial V2O5/WO3/TiO2 catalyst to investigate mercury oxidation in the presence of HCl and O2. Mercury oxidation was improved significantly in the presence of HCl and O2, and the Hg^0 oxidation efficiencies decreased slowly as the temperature increased from 200 to 400℃. Upon pretreatment with HCl and O2 at 350℃, the catalyst demonstrated higher catalytic activity for Hg^0 oxidation. Notably,the effect of pretreatment with HCl alone was not obvious. For the catalyst treated with HCl and O2, better performance was observed with lower reaction temperatures. The results showed that both HCl and Hg^0 were first adsorbed onto the catalyst and then reacted with O2 following its adsorption, which indicates that the oxidation of Hg^0 over the commercial catalyst followed the Langmuir–Hinshelwood mechanism. Several characterization techniques, including Hg^0temperature-programmed desorption（Hg-TPD） and X-ray photoelectron spectroscopy（XPS）, were employed in this work. Hg-TPD profiles showed that weakly adsorbed mercury species were converted to strongly bound species in the presence of HCl and O2. XPS patterns indicated that new chemisorbed oxygen species were formed by the adsorption of HCl, which consequently facilitated the oxidation of mercury.
