The study of the interaction of three glycol ethers, i.e. 2-methoxyethanol (ME), 2-ethoxyethanol (EE) and 2-butoxyethanol (BE) administered subcutaneously for 4 weeks and ethanol simultaneously given as 10% w/v soluti...The study of the interaction of three glycol ethers, i.e. 2-methoxyethanol (ME), 2-ethoxyethanol (EE) and 2-butoxyethanol (BE) administered subcutaneously for 4 weeks and ethanol simultaneously given as 10% w/v solution for drinking in male rats, was carried out from a toxicodynamic point of view. Administered alone, ME (2.5 and 5.0 mM/kg), EE (2.5 and 5.0 mM/kg) or BE (0.75 and 1.25 mM/kg) resulted in a decrease of red blood cells (RBC), packed cell volumes (PCV), and hemoglobin concentration (HGB), as well as an increase in mean corpuscular volume (MCV) and reticulocyte count (Ret). In the rats co-ex- posed to ethanol and EGAEs, a significantly less pronounced hematological changes in comparison with animal exposed to these ethers alone were seen. The rats simultaneously exposed to ethanol and both ME and EE at the lower dose demonstrated mainly protection from the alterations in leukocyte system. In contrast, in the rats which consumed ethanol and were simultaneously treated with the higher dose of ME or EE (5.0 mM/kg) the amelioration of same hematological parameters were displayed. The intake of ethanol along with BE treatment at both doses resulted in markedly ameliorated hematological parameters, compared to those which were changed by BE alone. In conclusion, the decrease of the hemolytic effects of EGAEs is ethanol dependent. Ethanol is a substrate of alcohol dehydrogenase (ADH), and affinity of this enzyme to ethanol is greater than that to glycol ethers. It is possible that ethanol results in the change in EGAEs metabolism.展开更多
Production o f aromatics from lignin has attracted much attention. Because of the coexistence of C-O and C-C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for de...Production o f aromatics from lignin has attracted much attention. Because of the coexistence of C-O and C-C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for developing a lignin catalytic decomposition process could be developed by exploring the transformation mechanisms of various model compounds. Herein, decomposition of a lignin model compound, 2-phenoxyacetophenone （2-PAP）, was investigated over several ce-sium-exchanged polyoxometalate （Cs-POM） catalysts. Decomposition of 2-PAP can follow two dif-ferent mechanisms： an active hydrogen transfer mechanism or an oxonium cation mechanism. The mechanism for most reactions depends on the competition between the acidity and redox proper-ties of the catalysts. The catalysts of POMs perform the following functions： promoting active hy-drogen liberated from ethanol and causing formation of and then temporarily stabilizing oxonium cations from 2-PAP. The use of Cs-PMo, which with strong redox ability, enhances hydrogen libera-tion and promotes liberated hydrogen transfer to the reaction intermediates. As a consequence, complete conversion of 2-PAP （〉99%） with excellent selectivities to the desired products （98.6% for phenol and 91.1% for acetophenone） can be achieved.展开更多
This paper investigates the effect of blending dimethyl ether(DME)and ethanol on the soot transition periods in ethylene counterflow diffusion flames by using a novel optical diagnostic method.The soot critical transi...This paper investigates the effect of blending dimethyl ether(DME)and ethanol on the soot transition periods in ethylene counterflow diffusion flames by using a novel optical diagnostic method.The soot critical transition point in different conditions is identified experimentally and numerically.Two kinds of flames are carried out to gain the soot critical transition point in counterflow diffusion flames by changing oxygen fraction(Xo)and changing volume flow rates of fuel and oxidizer(Qv).The red-green-blue(RGB)ratio method is used to precisely identify the soot critical transition point,and chemical kinetic simulations are performed to analyze the detailed reaction paths.The results show that compared to the ethylene flame,the soot critical transition point occurs at a higher Xoand a lower Qvwhen DME or ethanol is blended.The addition of DME and ethanol can inhibit soot formation,due to the degree of soot formation reaction being lower than the degree of the oxidation reaction in the blending flames.展开更多
文摘The study of the interaction of three glycol ethers, i.e. 2-methoxyethanol (ME), 2-ethoxyethanol (EE) and 2-butoxyethanol (BE) administered subcutaneously for 4 weeks and ethanol simultaneously given as 10% w/v solution for drinking in male rats, was carried out from a toxicodynamic point of view. Administered alone, ME (2.5 and 5.0 mM/kg), EE (2.5 and 5.0 mM/kg) or BE (0.75 and 1.25 mM/kg) resulted in a decrease of red blood cells (RBC), packed cell volumes (PCV), and hemoglobin concentration (HGB), as well as an increase in mean corpuscular volume (MCV) and reticulocyte count (Ret). In the rats co-ex- posed to ethanol and EGAEs, a significantly less pronounced hematological changes in comparison with animal exposed to these ethers alone were seen. The rats simultaneously exposed to ethanol and both ME and EE at the lower dose demonstrated mainly protection from the alterations in leukocyte system. In contrast, in the rats which consumed ethanol and were simultaneously treated with the higher dose of ME or EE (5.0 mM/kg) the amelioration of same hematological parameters were displayed. The intake of ethanol along with BE treatment at both doses resulted in markedly ameliorated hematological parameters, compared to those which were changed by BE alone. In conclusion, the decrease of the hemolytic effects of EGAEs is ethanol dependent. Ethanol is a substrate of alcohol dehydrogenase (ADH), and affinity of this enzyme to ethanol is greater than that to glycol ethers. It is possible that ethanol results in the change in EGAEs metabolism.
基金supported by the National Key Basic Research Program of China(973 program,2013CB934101)National Natural Science Foundation of China(21433002,21573046)+1 种基金China Postdoctoral Science Foundation(2016M601492)International Science and Technology Cooperation Projects of Guangxi(15104001-5)~~
文摘Production o f aromatics from lignin has attracted much attention. Because of the coexistence of C-O and C-C bonds and their complex combinations in the lignin macromolecular network, a plausible roadmap for developing a lignin catalytic decomposition process could be developed by exploring the transformation mechanisms of various model compounds. Herein, decomposition of a lignin model compound, 2-phenoxyacetophenone （2-PAP）, was investigated over several ce-sium-exchanged polyoxometalate （Cs-POM） catalysts. Decomposition of 2-PAP can follow two dif-ferent mechanisms： an active hydrogen transfer mechanism or an oxonium cation mechanism. The mechanism for most reactions depends on the competition between the acidity and redox proper-ties of the catalysts. The catalysts of POMs perform the following functions： promoting active hy-drogen liberated from ethanol and causing formation of and then temporarily stabilizing oxonium cations from 2-PAP. The use of Cs-PMo, which with strong redox ability, enhances hydrogen libera-tion and promotes liberated hydrogen transfer to the reaction intermediates. As a consequence, complete conversion of 2-PAP （〉99%） with excellent selectivities to the desired products （98.6% for phenol and 91.1% for acetophenone） can be achieved.
基金supported by the National Natural Science Foundation of China(Grant Nos.52106160 and 52076110)the Natural Science Foundation of Jiangsu Province(Grant No.BK20200490)。
文摘This paper investigates the effect of blending dimethyl ether(DME)and ethanol on the soot transition periods in ethylene counterflow diffusion flames by using a novel optical diagnostic method.The soot critical transition point in different conditions is identified experimentally and numerically.Two kinds of flames are carried out to gain the soot critical transition point in counterflow diffusion flames by changing oxygen fraction(Xo)and changing volume flow rates of fuel and oxidizer(Qv).The red-green-blue(RGB)ratio method is used to precisely identify the soot critical transition point,and chemical kinetic simulations are performed to analyze the detailed reaction paths.The results show that compared to the ethylene flame,the soot critical transition point occurs at a higher Xoand a lower Qvwhen DME or ethanol is blended.The addition of DME and ethanol can inhibit soot formation,due to the degree of soot formation reaction being lower than the degree of the oxidation reaction in the blending flames.
