Objective To clarify the influence on component and pharmacological action of Astragalus polysaccharides(APS) as complementary therapeutic agents prepared by different extraction and purification techniques.Methods Co...Objective To clarify the influence on component and pharmacological action of Astragalus polysaccharides(APS) as complementary therapeutic agents prepared by different extraction and purification techniques.Methods Components of APS prepared by different extraction and purification techniques were analyzed,and these APS were used for synergy and attenuation of chemotherapy,radiotherapy treatment with H22 liver cancer and Lewis lung cancer of tumor-bearing mice,and also used for the regulation of immune function to immunosuppression mice.Results Experimental data were analyzed by means of statistical method to get pharmaco-result:A3(extracted by microwave assistance and purified by membrane separation)>A4(extracted by refluxing and purified by membrane separation)>A1(extracted by refluxing and no purification)≈A2(extracted by microwave assistance and no purification).There were no significant differences on pharmacodynamic action between A1 and A2.However,compared with A1 and A2,it was worth noting that A3 and A4 exhibited good pharmacodynamic action.Then A3-in and A4-in,the samples in dialyzer after dialysis,were separated and purified to get homogeneous APS,which were the principal constituents of APS in dialyzer,with the molecular weight(Mw) of 7669 and 14142 determined by HPGPC,respectively.The average Mw of APS outside of the dialyzer,A3-out was 3102 and A4-out 3256,which were the main compositions of A3 and A4,accounted for 79.63% and 53.92%,respectively.Conclusion APS with Mw about 5000 Da exhibit better antitumor effect and immunological activity.Refluxing,microwave assistance extractions,and membrane enrichment techniques bring different cases on Mw distribution,components and pharmacodynamic action,and obviously exhibit relationship among component,Mw distribution,and pharmacological action.展开更多
The characteristics of dissolved organic matter（DOM） and bromide ion concentration have a significant influence on the formation of disinfection by-products（DBPs）. In order to identify the main DBP precursors, DOM...The characteristics of dissolved organic matter（DOM） and bromide ion concentration have a significant influence on the formation of disinfection by-products（DBPs）. In order to identify the main DBP precursors, DOM was divided into five fractions based on molecular weight（MW）, trihalomethane formation potential and haloacetic acid formation potential were determined for fractions, and the change in contents of different fractions and total DBPs during treatment processes（pre-chlorination, coagulation, sand filtration,disinfection） were studied. Moreover, the relationship between bromide concentration and DBP generation characteristics in processes was also analyzed. The results showed that the main DBP precursors were the fraction with MW 1 k Da and fraction with MW 3-10 k Da, and the DBP＇s generation ability of lower molecular weight DOM（ 10 k Da） was higher than that of higher molecular weight DOM. During different processes,pre-chlorination and disinfection had limited effect on removing organics but could alter the MW distribution, and coagulation and filtration could effectively remove organics with higher MW. For DBPs, trihalomethanes（THMs） were mainly generated in pre-chlorination and disinfection, while haloacetic acids（HAAs） were mostly generated during pre-chlorination; coagulation and sand filtration had little effect on THMs but resulted in a slight removal of HAAs. In addition, the results of ANOVA tests suggested that molecular sizes and treatment processes have significant influence on DBP formation. With increasing bromide concentration, the brominated DBPs significantly increased, but the bromine incorporation factor in the processes was basically consistent at each concentration.展开更多
Process parameters on enzymatic hydrolysis and molecular weight （MW） distribution of collagen hydrolysates from Gadus morrhua skin were investigated. The optimal process parameters were obtained by the single-factor...Process parameters on enzymatic hydrolysis and molecular weight （MW） distribution of collagen hydrolysates from Gadus morrhua skin were investigated. The optimal process parameters were obtained by the single-factor and orthogonal experiments. The molecular weight distribution of hydrolysates was determined using both Sephadex G25 partition and high speed liquid chromatography electricity spray mass spectrum （HPLC-ESI-MS）. Collagen hydrolysates were first gained by an alkaline protease ＂alcalase＂ for 3 h at temperature （50~C）, pH （10.0）, substrate concentration （75 g L-~）, and E/S （3%）. The molecular weight distribution of collagen hydrolysates ranged from 300 to 1 500 Da, and most of peptides were under 1 200 Da. Sephadex G25 partition and HPLC-ESI-MS should be successfully employed to determine the molecular weight distribution of collagen hydrolysates.展开更多
In this work, the enhanced dewaterabing characteristics of waste activated sludge using Fenton pretreatment was investigated in terms of effectiveness and statistical optimization. Response surface method （RSM） and ...In this work, the enhanced dewaterabing characteristics of waste activated sludge using Fenton pretreatment was investigated in terms of effectiveness and statistical optimization. Response surface method （RSM） and central composite design （CCD） were applied to evaluate and optimize the effectiveness of important operational parameters, i.e., H202 concentrations, Fe2＋ concentrations and initial pH values. A significant quadratic polynomial model was obtained （R2= 0.9189） with capillary suction time （CST） reduction efficiency as the response. Numerical optimization based on desirability function was carried out. The optimum values for H202, Fe2, and initial pH were found to be 178 mg-g-1 VSS （volatile suspended solids）, 211mg.gI VSS and 3.8, respectively, at which CST reduction efficiency of 98.25% could be achieved. This complied well with those predicted by the established polynomial model. The results indicate that Fenton pretreatment is an effective technique for advanced waste activated sludge dewatering. The enhancement of sludge dewaterability by Fenton＇s reagent lies in the migration of sludge bound water due to the disintegration of sludge flocs and microbial cells lysis.展开更多
基金The National Key Scientific and Technological Project in 11th Five-year Plan (No:2009ZX09301-007)
文摘Objective To clarify the influence on component and pharmacological action of Astragalus polysaccharides(APS) as complementary therapeutic agents prepared by different extraction and purification techniques.Methods Components of APS prepared by different extraction and purification techniques were analyzed,and these APS were used for synergy and attenuation of chemotherapy,radiotherapy treatment with H22 liver cancer and Lewis lung cancer of tumor-bearing mice,and also used for the regulation of immune function to immunosuppression mice.Results Experimental data were analyzed by means of statistical method to get pharmaco-result:A3(extracted by microwave assistance and purified by membrane separation)>A4(extracted by refluxing and purified by membrane separation)>A1(extracted by refluxing and no purification)≈A2(extracted by microwave assistance and no purification).There were no significant differences on pharmacodynamic action between A1 and A2.However,compared with A1 and A2,it was worth noting that A3 and A4 exhibited good pharmacodynamic action.Then A3-in and A4-in,the samples in dialyzer after dialysis,were separated and purified to get homogeneous APS,which were the principal constituents of APS in dialyzer,with the molecular weight(Mw) of 7669 and 14142 determined by HPGPC,respectively.The average Mw of APS outside of the dialyzer,A3-out was 3102 and A4-out 3256,which were the main compositions of A3 and A4,accounted for 79.63% and 53.92%,respectively.Conclusion APS with Mw about 5000 Da exhibit better antitumor effect and immunological activity.Refluxing,microwave assistance extractions,and membrane enrichment techniques bring different cases on Mw distribution,components and pharmacodynamic action,and obviously exhibit relationship among component,Mw distribution,and pharmacological action.
基金supported by the National Key Research and Development Program of China (No. 2016YFC0401108)
文摘The characteristics of dissolved organic matter（DOM） and bromide ion concentration have a significant influence on the formation of disinfection by-products（DBPs）. In order to identify the main DBP precursors, DOM was divided into five fractions based on molecular weight（MW）, trihalomethane formation potential and haloacetic acid formation potential were determined for fractions, and the change in contents of different fractions and total DBPs during treatment processes（pre-chlorination, coagulation, sand filtration,disinfection） were studied. Moreover, the relationship between bromide concentration and DBP generation characteristics in processes was also analyzed. The results showed that the main DBP precursors were the fraction with MW 1 k Da and fraction with MW 3-10 k Da, and the DBP＇s generation ability of lower molecular weight DOM（ 10 k Da） was higher than that of higher molecular weight DOM. During different processes,pre-chlorination and disinfection had limited effect on removing organics but could alter the MW distribution, and coagulation and filtration could effectively remove organics with higher MW. For DBPs, trihalomethanes（THMs） were mainly generated in pre-chlorination and disinfection, while haloacetic acids（HAAs） were mostly generated during pre-chlorination; coagulation and sand filtration had little effect on THMs but resulted in a slight removal of HAAs. In addition, the results of ANOVA tests suggested that molecular sizes and treatment processes have significant influence on DBP formation. With increasing bromide concentration, the brominated DBPs significantly increased, but the bromine incorporation factor in the processes was basically consistent at each concentration.
基金supported by Tianjin Committee of Science & Technology, China (06YFGZSH02300)
文摘Process parameters on enzymatic hydrolysis and molecular weight （MW） distribution of collagen hydrolysates from Gadus morrhua skin were investigated. The optimal process parameters were obtained by the single-factor and orthogonal experiments. The molecular weight distribution of hydrolysates was determined using both Sephadex G25 partition and high speed liquid chromatography electricity spray mass spectrum （HPLC-ESI-MS）. Collagen hydrolysates were first gained by an alkaline protease ＂alcalase＂ for 3 h at temperature （50~C）, pH （10.0）, substrate concentration （75 g L-~）, and E/S （3%）. The molecular weight distribution of collagen hydrolysates ranged from 300 to 1 500 Da, and most of peptides were under 1 200 Da. Sephadex G25 partition and HPLC-ESI-MS should be successfully employed to determine the molecular weight distribution of collagen hydrolysates.
文摘In this work, the enhanced dewaterabing characteristics of waste activated sludge using Fenton pretreatment was investigated in terms of effectiveness and statistical optimization. Response surface method （RSM） and central composite design （CCD） were applied to evaluate and optimize the effectiveness of important operational parameters, i.e., H202 concentrations, Fe2＋ concentrations and initial pH values. A significant quadratic polynomial model was obtained （R2= 0.9189） with capillary suction time （CST） reduction efficiency as the response. Numerical optimization based on desirability function was carried out. The optimum values for H202, Fe2, and initial pH were found to be 178 mg-g-1 VSS （volatile suspended solids）, 211mg.gI VSS and 3.8, respectively, at which CST reduction efficiency of 98.25% could be achieved. This complied well with those predicted by the established polynomial model. The results indicate that Fenton pretreatment is an effective technique for advanced waste activated sludge dewatering. The enhancement of sludge dewaterability by Fenton＇s reagent lies in the migration of sludge bound water due to the disintegration of sludge flocs and microbial cells lysis.
