The growth of human population leads to intensification of agriculture and promotes, through eutrophication, development of cyanobacteria. One of the most widespread and bloom-forming species in freshwater is toxic Mi...The growth of human population leads to intensification of agriculture and promotes, through eutrophication, development of cyanobacteria. One of the most widespread and bloom-forming species in freshwater is toxic Microcystis aeruginosa （M. aeruginosa）. Combustion of fossil fuels and metallurgical processes are the main sources of heavy metals contamination in surface water including cadmium （Cd） and lead （Pb）. The following study was conducted in order to determine the effect of 1- 20 mg. L-1 of Cd and Pb on photochemistry （using flow cytometry） and growth （based on chlorophyll concentra- tion） ofM. aeruginosa as well as to estimate levels of metal bioaccumulation. We have found that 1-10mg.L-1 of Cd and 1-5 rag. L1 of Pb induced continuous enhancement of chlorophyll fluorescence during 24 h of incubation. No significant degradation of chlorophyll was observed in these samples. At higher concentrations of 20 mg. L-1 of Cd and 10-20 mg.L-1 of Pb chlorophyll level significantly decreased and its fluorescence was quenched. M. aeruginosa demonstrated high capability of Cd and Pb bioaccumulation, proportionally to initial metal concentration. In samples with initial concentration of 20 mg. L-1 of Cd and Pb bioaccumulation of 87.3% and 90.1% was observed, respectively. Our study demonstrates that M. aeruginosa can potentially survive in highly metals polluted environments, be a primary source of toxic metals in the food chain and consequently contribute to enhanced toxicity of heavy metals to living organisms including human.展开更多
4-methylthio-3-butenyl isothiocyanate, a vola-tile component of Raphanus sativus leaf, was found to attract Myzus persicae in the olfactometer and the field and signifi-cant differences were found at 0.001 and 0.01 le...4-methylthio-3-butenyl isothiocyanate, a vola-tile component of Raphanus sativus leaf, was found to attract Myzus persicae in the olfactometer and the field and signifi-cant differences were found at 0.001 and 0.01 level when compared with control. The compound was identified by GC, GC-MS and NMR.展开更多
Bismuth oxide subacetate(CH3COO(BiO);BiOAc)with a large band gap energy(Eg)was first applied as an ultraviolet-light-driven photocatalyst in our group.MoS_(2)nanoflowers have been used to improve the visible-light pho...Bismuth oxide subacetate(CH3COO(BiO);BiOAc)with a large band gap energy(Eg)was first applied as an ultraviolet-light-driven photocatalyst in our group.MoS_(2)nanoflowers have been used to improve the visible-light photocatalytic activity of bismuth-based semiconductors with wide Eg because of their good visible-light response.Herein,the grinding-assisted solid-state reaction method was used to prepare a MoS_(2)/BiOAc composite to improve the visible-light photoreactivity of BiOAc.As compared with commonly used wet chemical and hydrothermal routes,the grinding-assisted synthesis facilitated heterogeneous nucleation,which was beneficial to achieving close contact and subsequent charge transfer and separation at the interfaces,resulting in enhanced photocatalytic activity for malachite green,methylene blue,and antibiotic tetracycline degradation under visible-light irradiation.Notably,the dispersion in the mixing solution of ethanol and water(v/v=1)of MoS_(2)nanosheets induced self-assembly into flower-like nanostructures,thus enhancing the photocatalytic activity of MoS_(2)/BiOAc.A possible mechanism for visible-light photocatalysis of MoS_(2)/BiOAc was proposed.展开更多
文摘The growth of human population leads to intensification of agriculture and promotes, through eutrophication, development of cyanobacteria. One of the most widespread and bloom-forming species in freshwater is toxic Microcystis aeruginosa （M. aeruginosa）. Combustion of fossil fuels and metallurgical processes are the main sources of heavy metals contamination in surface water including cadmium （Cd） and lead （Pb）. The following study was conducted in order to determine the effect of 1- 20 mg. L-1 of Cd and Pb on photochemistry （using flow cytometry） and growth （based on chlorophyll concentra- tion） ofM. aeruginosa as well as to estimate levels of metal bioaccumulation. We have found that 1-10mg.L-1 of Cd and 1-5 rag. L1 of Pb induced continuous enhancement of chlorophyll fluorescence during 24 h of incubation. No significant degradation of chlorophyll was observed in these samples. At higher concentrations of 20 mg. L-1 of Cd and 10-20 mg.L-1 of Pb chlorophyll level significantly decreased and its fluorescence was quenched. M. aeruginosa demonstrated high capability of Cd and Pb bioaccumulation, proportionally to initial metal concentration. In samples with initial concentration of 20 mg. L-1 of Cd and Pb bioaccumulation of 87.3% and 90.1% was observed, respectively. Our study demonstrates that M. aeruginosa can potentially survive in highly metals polluted environments, be a primary source of toxic metals in the food chain and consequently contribute to enhanced toxicity of heavy metals to living organisms including human.
基金This work was supported by the National Key Basic Research Project (Grant No. G2000016208) the Key Program of Chinese Academy of Sciences (Grant No. KSCX2-1-02-05).
文摘4-methylthio-3-butenyl isothiocyanate, a vola-tile component of Raphanus sativus leaf, was found to attract Myzus persicae in the olfactometer and the field and signifi-cant differences were found at 0.001 and 0.01 level when compared with control. The compound was identified by GC, GC-MS and NMR.
基金The work was financially supported by the National Natural Science Foundation of China(Grant No.51772155).
文摘Bismuth oxide subacetate(CH3COO(BiO);BiOAc)with a large band gap energy(Eg)was first applied as an ultraviolet-light-driven photocatalyst in our group.MoS_(2)nanoflowers have been used to improve the visible-light photocatalytic activity of bismuth-based semiconductors with wide Eg because of their good visible-light response.Herein,the grinding-assisted solid-state reaction method was used to prepare a MoS_(2)/BiOAc composite to improve the visible-light photoreactivity of BiOAc.As compared with commonly used wet chemical and hydrothermal routes,the grinding-assisted synthesis facilitated heterogeneous nucleation,which was beneficial to achieving close contact and subsequent charge transfer and separation at the interfaces,resulting in enhanced photocatalytic activity for malachite green,methylene blue,and antibiotic tetracycline degradation under visible-light irradiation.Notably,the dispersion in the mixing solution of ethanol and water(v/v=1)of MoS_(2)nanosheets induced self-assembly into flower-like nanostructures,thus enhancing the photocatalytic activity of MoS_(2)/BiOAc.A possible mechanism for visible-light photocatalysis of MoS_(2)/BiOAc was proposed.
