Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alk...Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alkyl(1-phenylsulfonyl) cycloalkane carboxylate com- pounds to their chromatographic retention (capacity factor lgKW) and the toxicity for photo- bacterium phosphoreum (–lgEC50) were developed by using the molecular structural parameters as theoretical descriptors (r2 = 0.9501, 0.9488). The two quantitative correlation equations were consequently cross validated by leave-one-out (LOO) validation method with q2 of 0.9113 and 0.9281, respectively. The result showed that the two equations achieved in this work by B3LYP/6-31G* are both more advantageous than those from AM1, and can be used to predict the lgKW and –lgEC50 of congeneric organics.展开更多
Benzophenones （BPs） are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transforma...Benzophenones （BPs） are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transformation behaviors and toxicity changes of 14 BP-type UV filters during chlorination disinfection treatment were investigated in this study. A new index, the acute toxicity formation potential, was proposed to evaluate the toxicity changes and potential risks of BP-type UV filters during chlorination treatment. It was found that 13 of 14 BP-type UV filters exhibited toxicity decreases in the chlorination disinfection process, more or less, while one showed a toxicity increase. The toxicity changes were dependent on substitution effects, such that 2,4-di-hydroxylated or 3-hydroxylated BPs exhibited significant toxicity decreases after chlorination treatment due to the ready cleavage of the aromatic ring. Importantly, the acute toxicity changes could be duplicated in an ambient water matrix.展开更多
A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent...A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent signal in the presence of genotoxic agents, such as Mitomycin C (MC). The performance of this whole-cell optical fiber sensor system was examined as a function of several parameters, including gel probe thickness, bacterial cell density, and diameter of the fiber-optic core and working temperature. An optimal response to a model genotoxicant, Mitomycin C, was achieved with agar-bacterial gel membrane: the thickness of gel membrane was about 5 mm; the cell density of bacteria in gel membrane was about 2.0×107 /ml; the diameter of fiber-optic core was 5.0 mm; the working temperature was 25 ℃. Under these optimized conditions, the response time was less than 10 h to Mitomycin C, with a lower detection threshold of 0.1 mg/L.展开更多
The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet （UV）, UV/H2O2, vacuum ultraviolet （VUV）, VUV/H2O2, and solar/TiO...The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet （UV）, UV/H2O2, vacuum ultraviolet （VUV）, VUV/H2O2, and solar/TiO2 processes, as well as to assess the toxicity of these intermediates. Eleven intermediates have been detected by gas chromatography-mass spectrometer, most of which were reported for the first time to our best knowledge. Combining the evolution of the dissolved organic carbon, CF and specific ultraviolet absorption at 254 nm, it could be deduced that cleavage of aromatic ring followed by dechlorination was the mechanism in solar/ TiO2 process, while dechlorination happened first and accumulation of aromatic intermediates occurred in the other processes. Different transformation pathways were proposed for UV-, VUV-assisted and solar/TiO2 processes, respectively. The acute toxicity was evaluated by means of Photobacterium phosphoreurn T3 spp. bioassay. It was believed that aromatic intermediates increased the toxicity and the ring-opening pathway in solar/TiO2 process could relieve the toxicity.展开更多
The single toxicity of aniline and its derivatives and the joint toxicity of the binary mixtures of aniline and each of its derivatives with the toxic unit ratios of 1∶1, 1∶4, 4∶1 to photobacterium phosphoreum were...The single toxicity of aniline and its derivatives and the joint toxicity of the binary mixtures of aniline and each of its derivatives with the toxic unit ratios of 1∶1, 1∶4, 4∶1 to photobacterium phosphoreum were determined, respectively. The toxic unit and the additive index were used to evaluate the joint toxicity. The result shows that the joint toxicity of each of the binary mixtures of aniline and each of its derivatives is mainly simple addition of the toxicities of the two compounds. On this basis, the QSAR equation that was built from the single toxicity of aniline was used to predict the toxicity of the derivatives of aniline in the mixtures. Good agreement between the predicted and experimental values was found with R 2=0.921.展开更多
基金This work was financially supported by the National Basic Research Program of China (2003CB415002), the China Postdoctoral Science Foundation (No. 2003033486) and the Natural Science Research Fund of University in Jiangsu (04KJB150149)
文摘Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alkyl(1-phenylsulfonyl) cycloalkane carboxylate com- pounds to their chromatographic retention (capacity factor lgKW) and the toxicity for photo- bacterium phosphoreum (–lgEC50) were developed by using the molecular structural parameters as theoretical descriptors (r2 = 0.9501, 0.9488). The two quantitative correlation equations were consequently cross validated by leave-one-out (LOO) validation method with q2 of 0.9113 and 0.9281, respectively. The result showed that the two equations achieved in this work by B3LYP/6-31G* are both more advantageous than those from AM1, and can be used to predict the lgKW and –lgEC50 of congeneric organics.
基金supported by the National Natural Science Foundation of China (No. 21377143, 21077123 and 20877090)
文摘Benzophenones （BPs） are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transformation behaviors and toxicity changes of 14 BP-type UV filters during chlorination disinfection treatment were investigated in this study. A new index, the acute toxicity formation potential, was proposed to evaluate the toxicity changes and potential risks of BP-type UV filters during chlorination treatment. It was found that 13 of 14 BP-type UV filters exhibited toxicity decreases in the chlorination disinfection process, more or less, while one showed a toxicity increase. The toxicity changes were dependent on substitution effects, such that 2,4-di-hydroxylated or 3-hydroxylated BPs exhibited significant toxicity decreases after chlorination treatment due to the ready cleavage of the aromatic ring. Importantly, the acute toxicity changes could be duplicated in an ambient water matrix.
文摘采用误差反传前向人工神经网络(artificial neural network,ANN)建立了24种取代芳烃的结构与其对发光菌的急性毒性之间的定量关系模型(ANN模型)。以24种取代芳烃的量子化学参数作为输入,急性毒性作为输出,采用内外双重验证的办法分析和检验所得模型的稳定性和外部预测能力。所构建网络模型的相关系数为0.9834、交叉检验相关系数为0.9780、标准偏差为0.11、残差绝对值≤0.33,应用于外部预测集,外部预测集相关系数为0.9955;而多元线性回归(multiple linear regression,MLR)法模型的相关系数为0.9786、标准偏差为0.12、残差绝对值≤0.36,外部预测集相关系数为0.9904。结果表明,ANN模型获得了比MLR模型更好的拟合效果。
文摘A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent signal in the presence of genotoxic agents, such as Mitomycin C (MC). The performance of this whole-cell optical fiber sensor system was examined as a function of several parameters, including gel probe thickness, bacterial cell density, and diameter of the fiber-optic core and working temperature. An optimal response to a model genotoxicant, Mitomycin C, was achieved with agar-bacterial gel membrane: the thickness of gel membrane was about 5 mm; the cell density of bacteria in gel membrane was about 2.0×107 /ml; the diameter of fiber-optic core was 5.0 mm; the working temperature was 25 ℃. Under these optimized conditions, the response time was less than 10 h to Mitomycin C, with a lower detection threshold of 0.1 mg/L.
基金This study was supported by the National Natural Science Foundation of China （Grant Nos. 20677015 and 40871223）, the National High Technology Research and Development Program of China （No. 2007AA06Z331）, the Chinese Shanghai Leading Academic Discipline Project （B506） and National Post-Doctoral Science Foundation （No. 2011M500071）.
文摘The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet （UV）, UV/H2O2, vacuum ultraviolet （VUV）, VUV/H2O2, and solar/TiO2 processes, as well as to assess the toxicity of these intermediates. Eleven intermediates have been detected by gas chromatography-mass spectrometer, most of which were reported for the first time to our best knowledge. Combining the evolution of the dissolved organic carbon, CF and specific ultraviolet absorption at 254 nm, it could be deduced that cleavage of aromatic ring followed by dechlorination was the mechanism in solar/ TiO2 process, while dechlorination happened first and accumulation of aromatic intermediates occurred in the other processes. Different transformation pathways were proposed for UV-, VUV-assisted and solar/TiO2 processes, respectively. The acute toxicity was evaluated by means of Photobacterium phosphoreurn T3 spp. bioassay. It was believed that aromatic intermediates increased the toxicity and the ring-opening pathway in solar/TiO2 process could relieve the toxicity.
文摘The single toxicity of aniline and its derivatives and the joint toxicity of the binary mixtures of aniline and each of its derivatives with the toxic unit ratios of 1∶1, 1∶4, 4∶1 to photobacterium phosphoreum were determined, respectively. The toxic unit and the additive index were used to evaluate the joint toxicity. The result shows that the joint toxicity of each of the binary mixtures of aniline and each of its derivatives is mainly simple addition of the toxicities of the two compounds. On this basis, the QSAR equation that was built from the single toxicity of aniline was used to predict the toxicity of the derivatives of aniline in the mixtures. Good agreement between the predicted and experimental values was found with R 2=0.921.
