核酸适配体是指能以极高的亲和力和特异性与靶分子结合的寡核苷酸序列,可识别的靶分子范围非常广,并均可通过指数富集的配体系统进化(systematic evolution of ligands by exponential enrichment,SELEX)技术筛选得到。近年来,在传统SE...核酸适配体是指能以极高的亲和力和特异性与靶分子结合的寡核苷酸序列,可识别的靶分子范围非常广,并均可通过指数富集的配体系统进化(systematic evolution of ligands by exponential enrichment,SELEX)技术筛选得到。近年来,在传统SELEX技术的基础上,新的SELEX技术不断出现。这些新技术的出现,在不断完善SELEX技术的同时,也极大地推动了适配体技术在各学科领域中的发展及应用。本文对核酸适配体的筛选方法进行了总结,并介绍了其在食品检测领域的应用现状和发展方向,为核酸适配体的筛选与应用提供了参考。展开更多
The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can...The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can release H+ and concentrate Fe3+; Fe2+ is movable between agar-simulated EPS phase and bulk solution phase, but it is difficult for Fe3+ to move due to its hydroxylation and EPS complex action; A. ferrooxidans first prefer Fe2+ as energy to metabolize compared with chalcopyrite, and a suitable simulated EPS environment for bacterial living is at about pH 1.8; the iron precipitates and jarosites formed by a lot of biologically oxidized Fe3+ cover the simulated EPS easily and form an impermeable deposit acting as a limited barrier of ion transport that attenuates the aggressiveness of the bioleaching attack. The EPS layer blocked by iron precipitates or jarosites is responsible for the chalcopyrite passivation.展开更多
As thiourea and sulfur-containing mixed additives contaminate cathodic copper,inhibition behavior of some new mixed additives such as gelatin+hexadecylpyridinium bromide (HDPBr),gelatin+polyethylene glycol(PEG),gelati...As thiourea and sulfur-containing mixed additives contaminate cathodic copper,inhibition behavior of some new mixed additives such as gelatin+hexadecylpyridinium bromide (HDPBr),gelatin+polyethylene glycol(PEG),gelatin+polyacryl amide (PAM),gelatin+PEG+cetyl-tri-methyl ammonium bromide (CTABr) and gelatin+PAM+CTABr was investigated by cyclic voltammetry as well as cathodic polarization in order to improve the quality of cathodic copper in bio-metallurgical process.The results indicate that the inhibition performances of these additives are dependent on complex and adsorption behaviors as well as the deposit potential.For a solution of acidic copper sulpate containing 40 g/L Cu2+ and 180 g/L H2SO4,the additive (gelatin+HDPBr) is the most efficient among the investigated additives because HDPBr with a large organic cation and π electron can adsorb on the cathodic surface to block the active sites and Br-ion can precipitate Cu2+ to form Cu2Br2.The additive (gelatin+PAM) also has a better inhibition performance,while the additives (gelatin+PEG),(gelatin+PEG+CTABr) and (gelatin+PAM+CTABr) are comparatively lower inhibition performance compared with the additive (gelatin+thiourea) which has been frequently used so far.展开更多
文摘核酸适配体是指能以极高的亲和力和特异性与靶分子结合的寡核苷酸序列,可识别的靶分子范围非常广,并均可通过指数富集的配体系统进化(systematic evolution of ligands by exponential enrichment,SELEX)技术筛选得到。近年来,在传统SELEX技术的基础上,新的SELEX技术不断出现。这些新技术的出现,在不断完善SELEX技术的同时,也极大地推动了适配体技术在各学科领域中的发展及应用。本文对核酸适配体的筛选方法进行了总结,并介绍了其在食品检测领域的应用现状和发展方向,为核酸适配体的筛选与应用提供了参考。
基金Project (2010CB630901) supported by the National Basic Research Program of ChinaProject (50621063) supported by the National Natural Science Foundation of China
基金Project(2010CB630900) supported by the National Basic Research Program of ChinaProject(50621063) supported by the National Nature Science Foundation of China
文摘The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can release H+ and concentrate Fe3+; Fe2+ is movable between agar-simulated EPS phase and bulk solution phase, but it is difficult for Fe3+ to move due to its hydroxylation and EPS complex action; A. ferrooxidans first prefer Fe2+ as energy to metabolize compared with chalcopyrite, and a suitable simulated EPS environment for bacterial living is at about pH 1.8; the iron precipitates and jarosites formed by a lot of biologically oxidized Fe3+ cover the simulated EPS easily and form an impermeable deposit acting as a limited barrier of ion transport that attenuates the aggressiveness of the bioleaching attack. The EPS layer blocked by iron precipitates or jarosites is responsible for the chalcopyrite passivation.
基金Project(2004CB619200) supported by the National Basic Research Program of China
文摘As thiourea and sulfur-containing mixed additives contaminate cathodic copper,inhibition behavior of some new mixed additives such as gelatin+hexadecylpyridinium bromide (HDPBr),gelatin+polyethylene glycol(PEG),gelatin+polyacryl amide (PAM),gelatin+PEG+cetyl-tri-methyl ammonium bromide (CTABr) and gelatin+PAM+CTABr was investigated by cyclic voltammetry as well as cathodic polarization in order to improve the quality of cathodic copper in bio-metallurgical process.The results indicate that the inhibition performances of these additives are dependent on complex and adsorption behaviors as well as the deposit potential.For a solution of acidic copper sulpate containing 40 g/L Cu2+ and 180 g/L H2SO4,the additive (gelatin+HDPBr) is the most efficient among the investigated additives because HDPBr with a large organic cation and π electron can adsorb on the cathodic surface to block the active sites and Br-ion can precipitate Cu2+ to form Cu2Br2.The additive (gelatin+PAM) also has a better inhibition performance,while the additives (gelatin+PEG),(gelatin+PEG+CTABr) and (gelatin+PAM+CTABr) are comparatively lower inhibition performance compared with the additive (gelatin+thiourea) which has been frequently used so far.
基金Project(2004CB619204)supported by the National Basic Research Program of ChinaProject(50621063)supported by the Chinese Science Foundation for Distinguished Group
