The aggregation ofβ-amyloid(Aβ)protein into toxic intermediates and mature fibrils is considered to be one of the main causes of Alzheimer's disease(AD).Small molecules as one of blockers are expected to be the ...The aggregation ofβ-amyloid(Aβ)protein into toxic intermediates and mature fibrils is considered to be one of the main causes of Alzheimer's disease(AD).Small molecules as one of blockers are expected to be the potential drug treatment for the disease.However,the nucleation process in molecular assembly is less informative in the literatures.In this work,the formation of Aβ(16-22)peptides was investigated with the presence of small molecule of fast green(FG)at the initial aggregation stage.The results exhibited the tunable inhibitory ability of FG molecules on Aβ(16-22)peptides.Atomic force microscopy(AFM)demonstrated that the inhibitory effect would be dependent on the dose of FG molecules,which could delay the lag time(nucleation)and form single layer conjugates.Spectral measurements further showed that theβ-sheet secondary structure of Aβ(16-22)reduced dramatically after the presence of FG molecules.Instead,non-β-sheet nanosheets were formed when the FG/Aβ(16-22)ratio reached 1:1.In addition,the cytotoxicity of aggregates reduced greatly with the presence of FG molecules compared with the Aβ(16-22)fibrils.Overall,this study provided a method for suppressing the toxic amyloid aggregates by FG molecules efficiently,and also showed a strategy for fabrication of two-dimensional materials by small molecules.展开更多
The kinetics of the reaction of Fast Green dye(FG)with cetylpyridinum chloride was studied in alkaline medium by UV-Visible spectrophotometer.Reduction of Fast Green dye was carried out by varying the fast green dye c...The kinetics of the reaction of Fast Green dye(FG)with cetylpyridinum chloride was studied in alkaline medium by UV-Visible spectrophotometer.Reduction of Fast Green dye was carried out by varying the fast green dye concentration,cetylpyridinum chloride concentration and concentration of sodium hydroxide.In the present study the reduction of dye was carried out in order to reduce the color content.The interaction of dye was carried out with reducing analyte(cetylpyridinum chloride).The rate of the reaction was determined by varying the above parameters at different temperatures.It was observed that the reduction followed pseudo first-order kinetics with respect to dye,surfactant,OH–ion concentration according to the following reaction pathway.reaction like entropy of activation(ΔS)and free energy of activation(ΔG)showed the extremely solvated states of transient complex which was less disorderly arranged than the oxidized form of dye,whereas Ea values reflects a high amount of energy required for the reduction of dye with cetylpyridinum chloride.展开更多
An untried,low cost,locally available biosorbent for its anionic dye removal capacity from aqueous solution was investigated.Powder prepared from peanut hull had been used for biosorption of three anionic dyes,amarant...An untried,low cost,locally available biosorbent for its anionic dye removal capacity from aqueous solution was investigated.Powder prepared from peanut hull had been used for biosorption of three anionic dyes,amaranth (Am),sunset yellow (SY) and fast green FCF (FG).The effects of various experimental parameters (e.g.initial pH and dye concentration,sorbent dosage,particle size,ion strength,contact time etc.) were examined and optimal experimental conditions were decided.At initial pH 2.0,three dyes studied could be removed effectively.When the dye concentration was 50 mg·L -1 ,the percentages of dyes sorbed was 95.5% in Am,91.3% in SY and 94.98% in FG,respectively.The ratios of dyes sorbed had neared maximum values in all three dyes when sorbent dose of 5.0 g·L -1 and the sorbent particle size in 80～100 mesh was used.The increasing the ion strength of solution caused the decrease in biosorption percentages of dyes.The equilibrium values arrived at about 36 hour for all three dyes.The isothermal data of biosorption followed the Langmuir and Freundlich models.The biosorption processes conformed the pseudo-first-order rate kinetics.The results indicated that powdered peanut hull was an attractive candidate for removing anionic dyes from dye wastewater.展开更多
基金Project supported by the National Natural Science Foundation of China (Grand No. 11804174)Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life SciencesK. C. Wong Magna Fund in Ningbo University
文摘The aggregation ofβ-amyloid(Aβ)protein into toxic intermediates and mature fibrils is considered to be one of the main causes of Alzheimer's disease(AD).Small molecules as one of blockers are expected to be the potential drug treatment for the disease.However,the nucleation process in molecular assembly is less informative in the literatures.In this work,the formation of Aβ(16-22)peptides was investigated with the presence of small molecule of fast green(FG)at the initial aggregation stage.The results exhibited the tunable inhibitory ability of FG molecules on Aβ(16-22)peptides.Atomic force microscopy(AFM)demonstrated that the inhibitory effect would be dependent on the dose of FG molecules,which could delay the lag time(nucleation)and form single layer conjugates.Spectral measurements further showed that theβ-sheet secondary structure of Aβ(16-22)reduced dramatically after the presence of FG molecules.Instead,non-β-sheet nanosheets were formed when the FG/Aβ(16-22)ratio reached 1:1.In addition,the cytotoxicity of aggregates reduced greatly with the presence of FG molecules compared with the Aβ(16-22)fibrils.Overall,this study provided a method for suppressing the toxic amyloid aggregates by FG molecules efficiently,and also showed a strategy for fabrication of two-dimensional materials by small molecules.
文摘The kinetics of the reaction of Fast Green dye(FG)with cetylpyridinum chloride was studied in alkaline medium by UV-Visible spectrophotometer.Reduction of Fast Green dye was carried out by varying the fast green dye concentration,cetylpyridinum chloride concentration and concentration of sodium hydroxide.In the present study the reduction of dye was carried out in order to reduce the color content.The interaction of dye was carried out with reducing analyte(cetylpyridinum chloride).The rate of the reaction was determined by varying the above parameters at different temperatures.It was observed that the reduction followed pseudo first-order kinetics with respect to dye,surfactant,OH–ion concentration according to the following reaction pathway.reaction like entropy of activation(ΔS)and free energy of activation(ΔG)showed the extremely solvated states of transient complex which was less disorderly arranged than the oxidized form of dye,whereas Ea values reflects a high amount of energy required for the reduction of dye with cetylpyridinum chloride.
文摘An untried,low cost,locally available biosorbent for its anionic dye removal capacity from aqueous solution was investigated.Powder prepared from peanut hull had been used for biosorption of three anionic dyes,amaranth (Am),sunset yellow (SY) and fast green FCF (FG).The effects of various experimental parameters (e.g.initial pH and dye concentration,sorbent dosage,particle size,ion strength,contact time etc.) were examined and optimal experimental conditions were decided.At initial pH 2.0,three dyes studied could be removed effectively.When the dye concentration was 50 mg·L -1 ,the percentages of dyes sorbed was 95.5% in Am,91.3% in SY and 94.98% in FG,respectively.The ratios of dyes sorbed had neared maximum values in all three dyes when sorbent dose of 5.0 g·L -1 and the sorbent particle size in 80～100 mesh was used.The increasing the ion strength of solution caused the decrease in biosorption percentages of dyes.The equilibrium values arrived at about 36 hour for all three dyes.The isothermal data of biosorption followed the Langmuir and Freundlich models.The biosorption processes conformed the pseudo-first-order rate kinetics.The results indicated that powdered peanut hull was an attractive candidate for removing anionic dyes from dye wastewater.
