Objective:To reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits,flowers and leaves of Lawsonia inermis(L against)some pathogenic bacteria.Methods:Powders of f...Objective:To reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits,flowers and leaves of Lawsonia inermis(L against)some pathogenic bacteria.Methods:Powders of fruits,flowers and leaves of L inermis were continuously extracted with dichloromethane(DCM),ethyl acetate and ethanol at ambient temperature.The dried extracts were prepared into different concentrations and tested for antibacterial activity by agar well diffusion method,and also the extracts were tested to detennine the available phytochemicals.Results:Except DCM extract of flower all other test extracts revealed inhibitory effect on all tested bacteria and their inhibitory effect differed significantly(P<0.05).The highest inhibitory effect was showed by ethyl acetate extract of flower against Staphylococcus aureus(S.aureus)and Pseudomonas aeruginosa(P.aeruginosa),and ethyl acetate extract of fruit on Escherichia coli(E.coli)and Bacillus subtilis(6.subtilis).The ethyl acetate and ethanol extracts of flower,fruit and leaf expressed inhibition even at 1 mg/100μl against all test bacteria.Among the tested phytochemicals flavonoids were detected in all test extracts except DCM extract of flower.Conclusions:The study demonstrated that the ethyl acetate and ethanol extracts of fruit and flower of L inermis are potentially better source of antibacterial agents compared to leaf extracts of respective solvents.展开更多
The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by a Russian nuclear facility producing weapon-grade plutonium, which has been in operation for many ye...The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by a Russian nuclear facility producing weapon-grade plutonium, which has been in operation for many years. Examination of Yenisei River sediment samples revealed the presence of artificial radionuclides typical of radioactive discharge from the Mining-and-Chemical- Combine (MCC) nuclear facility: isotopes of europium (152Eu, 154Eu, and 155Eu), cesium (137Cs and 134Cs), 60Co, 90Sr, and transuranium elements. The MCC is also a source of radioactive particles in the Yenisei. New data on radionuclide concentrations in sediments and radioactive particles in the Yenisei River were obtained using a wide range of analytical methods. Sequential extraction performed on samples of sediment cores showed different degrees of potential environmental availability of artificial radionuclides and uranium. In a few samples, 241Am was present in the unextractable form, which may be accounted for by the presence of microparticles of the reactor fuel. These microparticles were investigated using scanning electron microscopy, and their reactor origin was confirmed.展开更多
为合理评价污染场地风险,以我国云南省某铜堆浸场下游农田土为例,测定土壤中Cu、Pb、Cd和As等4种重金属总量,采用改进BCR(Bureau of European Communities Reference)连续提取法测定4种重金属赋存形态,分析4种重金属间的相关性,并使用...为合理评价污染场地风险,以我国云南省某铜堆浸场下游农田土为例,测定土壤中Cu、Pb、Cd和As等4种重金属总量,采用改进BCR(Bureau of European Communities Reference)连续提取法测定4种重金属赋存形态,分析4种重金属间的相关性,并使用地累积指数法、次生相与原生相比值法(RSP)和风险评价编码法(RAC)对场地土壤重金属污染和潜在风险程度进行评价。结果发现,重金属Cu、Pb、Cd和As平均的含量分别为39.50、46.98、0.16、82.67mg⋅kg^(-1),较云南省重金属背景值,4种重金属超标率分别为0、83.33%、33.33%和100.00%,其中As污染需要特别关注;提取重金属赋存形态结果显示,土样中Cu、Pb、Cd和As均以残渣态为主,占比为83.14%~95.62%,表明4种重金属均以稳定形态存在于土体中;对比3种评价方法,评价结果存在明显差异,地累积指数Igeo结果显示土壤仅As存在污染超标现象,其余3种重金属均无污染,次生相与原生相比值法结果显示,4种重金属对环境均无污染,而风险评价编码法结果显示,Cd对土壤环境存在低风险,其余3种重金属则无风险。对比发现,仅以污染场地土壤重金属总量作为评价指标会一定程度夸大污染风险,应综合重金属总量及赋存形态含量进行分析。虽然重金属元素污染总量较高,但活跃性重金属含量非常低,向环境中扩散的风险也非常低。因此,研究区重金属污染程度较轻,潜在生态风险为低风险。展开更多
Four different methods,namely mineralogical analysis,three-stage BCR sequential extraction procedure,dynamic leaching test and Hakanson Potential Ecological Risk Index Method were used to access the environmental acti...Four different methods,namely mineralogical analysis,three-stage BCR sequential extraction procedure,dynamic leaching test and Hakanson Potential Ecological Risk Index Method were used to access the environmental activity and potential ecological risks of heavy metals in zinc leaching residue.The results demonstrate that the environmental activity of heavy metals declines in the following order：CdZnCuAsPb.Potential ecological risk indices for single heavy metal are CdZnCuAsPb.Cd has serious potential ecological risk to the ecological environment and contributes most to the potential toxicity response indices for various heavy metals in the residue.展开更多
Sequential extraction method was used to analyze and distinguish various chemical bound forms of copper and zine in rape and wheat.The results show that in these two crops,copper was mainly in the form of wate soluble...Sequential extraction method was used to analyze and distinguish various chemical bound forms of copper and zine in rape and wheat.The results show that in these two crops,copper was mainly in the form of wate soluble and ethanol soluble, which can be easily transferred in crops.The total content of various chemical bound forms of copper was higher in aboveground part than in underground part,and their content was decreased in the order of water soluble form(W.S.form)>residual form (Re.form)>ethanol soluble form(Eth.S.form)>acid soluble form (A.S.form). Zinc was mainly in the form of acid soluble, which is hard to be transferred in crops.The total content of various chemical bound forms of zinc was lower in aboveground part than in roots, and their content was decreased in the order of A.S.form>Re.form>W.S.form>Eth.S.form.In comparing with copper,a large amount of zinc was enriched in seeds and pods of rape.展开更多
基金Supported by Ministry of Higher EducationSri Lanka for providing the financial assistance for the work as payment of research allowance in accordance with circular no1/2011
文摘Objective:To reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits,flowers and leaves of Lawsonia inermis(L against)some pathogenic bacteria.Methods:Powders of fruits,flowers and leaves of L inermis were continuously extracted with dichloromethane(DCM),ethyl acetate and ethanol at ambient temperature.The dried extracts were prepared into different concentrations and tested for antibacterial activity by agar well diffusion method,and also the extracts were tested to detennine the available phytochemicals.Results:Except DCM extract of flower all other test extracts revealed inhibitory effect on all tested bacteria and their inhibitory effect differed significantly(P<0.05).The highest inhibitory effect was showed by ethyl acetate extract of flower against Staphylococcus aureus(S.aureus)and Pseudomonas aeruginosa(P.aeruginosa),and ethyl acetate extract of fruit on Escherichia coli(E.coli)and Bacillus subtilis(6.subtilis).The ethyl acetate and ethanol extracts of flower,fruit and leaf expressed inhibition even at 1 mg/100μl against all test bacteria.Among the tested phytochemicals flavonoids were detected in all test extracts except DCM extract of flower.Conclusions:The study demonstrated that the ethyl acetate and ethanol extracts of fruit and flower of L inermis are potentially better source of antibacterial agents compared to leaf extracts of respective solvents.
文摘The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by a Russian nuclear facility producing weapon-grade plutonium, which has been in operation for many years. Examination of Yenisei River sediment samples revealed the presence of artificial radionuclides typical of radioactive discharge from the Mining-and-Chemical- Combine (MCC) nuclear facility: isotopes of europium (152Eu, 154Eu, and 155Eu), cesium (137Cs and 134Cs), 60Co, 90Sr, and transuranium elements. The MCC is also a source of radioactive particles in the Yenisei. New data on radionuclide concentrations in sediments and radioactive particles in the Yenisei River were obtained using a wide range of analytical methods. Sequential extraction performed on samples of sediment cores showed different degrees of potential environmental availability of artificial radionuclides and uranium. In a few samples, 241Am was present in the unextractable form, which may be accounted for by the presence of microparticles of the reactor fuel. These microparticles were investigated using scanning electron microscopy, and their reactor origin was confirmed.
文摘为合理评价污染场地风险,以我国云南省某铜堆浸场下游农田土为例,测定土壤中Cu、Pb、Cd和As等4种重金属总量,采用改进BCR(Bureau of European Communities Reference)连续提取法测定4种重金属赋存形态,分析4种重金属间的相关性,并使用地累积指数法、次生相与原生相比值法(RSP)和风险评价编码法(RAC)对场地土壤重金属污染和潜在风险程度进行评价。结果发现,重金属Cu、Pb、Cd和As平均的含量分别为39.50、46.98、0.16、82.67mg⋅kg^(-1),较云南省重金属背景值,4种重金属超标率分别为0、83.33%、33.33%和100.00%,其中As污染需要特别关注;提取重金属赋存形态结果显示,土样中Cu、Pb、Cd和As均以残渣态为主,占比为83.14%~95.62%,表明4种重金属均以稳定形态存在于土体中;对比3种评价方法,评价结果存在明显差异,地累积指数Igeo结果显示土壤仅As存在污染超标现象,其余3种重金属均无污染,次生相与原生相比值法结果显示,4种重金属对环境均无污染,而风险评价编码法结果显示,Cd对土壤环境存在低风险,其余3种重金属则无风险。对比发现,仅以污染场地土壤重金属总量作为评价指标会一定程度夸大污染风险,应综合重金属总量及赋存形态含量进行分析。虽然重金属元素污染总量较高,但活跃性重金属含量非常低,向环境中扩散的风险也非常低。因此,研究区重金属污染程度较轻,潜在生态风险为低风险。
基金Project(50925417) supported by the National Natural Science Funds for Distinguished Young Scholar of ChinaProject(2010AA065203) supported by the High Technology Research and Development Program of China+2 种基金Project(2010-609) Supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education,ChinaProject(ncet-10-0840) supported by Program for New Century Excellent Talents in UniversityProject(2012FJ1080) supported by Key Projects of Science and Technology of Hunan Province,China
文摘Four different methods,namely mineralogical analysis,three-stage BCR sequential extraction procedure,dynamic leaching test and Hakanson Potential Ecological Risk Index Method were used to access the environmental activity and potential ecological risks of heavy metals in zinc leaching residue.The results demonstrate that the environmental activity of heavy metals declines in the following order：CdZnCuAsPb.Potential ecological risk indices for single heavy metal are CdZnCuAsPb.Cd has serious potential ecological risk to the ecological environment and contributes most to the potential toxicity response indices for various heavy metals in the residue.
文摘Sequential extraction method was used to analyze and distinguish various chemical bound forms of copper and zine in rape and wheat.The results show that in these two crops,copper was mainly in the form of wate soluble and ethanol soluble, which can be easily transferred in crops.The total content of various chemical bound forms of copper was higher in aboveground part than in underground part,and their content was decreased in the order of water soluble form(W.S.form)>residual form (Re.form)>ethanol soluble form(Eth.S.form)>acid soluble form (A.S.form). Zinc was mainly in the form of acid soluble, which is hard to be transferred in crops.The total content of various chemical bound forms of zinc was lower in aboveground part than in roots, and their content was decreased in the order of A.S.form>Re.form>W.S.form>Eth.S.form.In comparing with copper,a large amount of zinc was enriched in seeds and pods of rape.
