Critical concentrations of α-(1→3)-D-glucan L-FV-Ⅱ from Lentinus edodes were studied by viscometry andfluorescence probe techniques. The dependence of the reduced viscosity on concentration of the glucan in 0.5 mol...Critical concentrations of α-(1→3)-D-glucan L-FV-Ⅱ from Lentinus edodes were studied by viscometry andfluorescence probe techniques. The dependence of the reduced viscosity on concentration of the glucan in 0.5 mol/L NaOHaqueous solutions with or without urea showed two turning points corresponding to the dynamic contact concentration c_s andthe overlap concentration c~* of the polymer. The values of c_s and c~* were found to be 1×10^(-3) g cm^(-3) and 1.1×10^(-2) g cm^(-3),respectively, for L-FV-Ⅱ in 0.5 mol/L NaOH aqueous solutions. The two critical concentrations of L-FV-Ⅱ in 0.5 mol/LNaOH aqueous solutions were also found to be 1.2×10^(-3) g cm^(-3) fbr c_s and 9.2×10^(-3) g cm^(-3) for c~* from the concentrationdependence of phenanthrene fluorescence intensities. The overlap concentration c~* of L-FV-Ⅱ in 0.5 mol/L NaOH aqueoussolutions was lower than that of polystyrene with same molecular weight in benzene, owing to the fact that polysaccharidetends to undergo aggregation caused by intermolecular hydrogen bonding. A normal viscosity behavior of L-FV-Ⅱ in 0.5 mol/L urea/0.5 mol/L NaOH aqueous solutions can still be observed in an extremely low concentration range at 25℃.展开更多
目的：探讨血浆（1‐3）‐β‐D葡聚糖检测对艾滋病（AIDS）患者合并播散性马尔尼菲青霉菌病（DPsM ）的诊断价值，为临床提供早期治疗依据。方法回顾性研究2010年4月－2014年7月174例 AIDS住院患者，分为观察组82例为临床确诊合并播散...目的：探讨血浆（1‐3）‐β‐D葡聚糖检测对艾滋病（AIDS）患者合并播散性马尔尼菲青霉菌病（DPsM ）的诊断价值，为临床提供早期治疗依据。方法回顾性研究2010年4月－2014年7月174例 AIDS住院患者，分为观察组82例为临床确诊合并播散性马尔尼菲青霉菌病，对照组92例为无机会性感染，运用M B‐80微生物快速动态检测系统进行血浆（1‐3）‐β‐D葡聚糖检测（G试验），比较两组血浆（1‐3）‐β‐D葡聚糖水平，绘制受试者工作特征（ROC）曲线，确定血浆（1‐3）‐β‐D葡聚糖水平诊断播散性马尔尼菲青霉菌病的最佳诊断值。结果观察组和对照组血浆（1‐3）‐β‐D葡聚糖检测浓度中位数分别为198．0 pg／ml和24．0 pg／ml ，两组比较差异有统计学意义（P＜0．05）；ROC曲线分析结果显示，血浆（1‐3）‐β‐D葡聚糖用于诊断播散性马尔尼菲青霉菌病的最佳诊断值为75 pg／m l ，曲线下面积（A U C ）为0．843（95％ C I 0．784～0．903，P＜0．05），灵敏度、特异性、阳性预测值、阴性预测值分别为74．40％、84．80％、81．30％和78．79％。结论血浆（1‐3）‐β‐D葡聚糖检测具有早期诊断播散性马尔尼菲青霉菌病的临床应用价值，最佳诊断值为75 pg／m l。展开更多
分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露...分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露聚糖和蛋白质这两种成分。但先用c(NaOH)=1 0mol/L的水溶液提取,再用w(CH3COOH)=4%的醋酸溶液处理时,产品为高纯度的(1→3) β D 葡聚糖。此结论由傅立叶红外光谱和核磁共振碳谱得到进一步的证实。接着从其水解机理上阐述了产生上述两种不同结果的原因,从而说明了酸碱法是从啤酒酵母中提取(1→3) β D 葡聚糖的理想途径。展开更多
基金This work was supported by the National Natural Science Foundation of China (No. 29374170) and the Research Grant Council of Hong Kong Government Earmarked Grant (CUHK 4161/99M).
文摘Critical concentrations of α-(1→3)-D-glucan L-FV-Ⅱ from Lentinus edodes were studied by viscometry andfluorescence probe techniques. The dependence of the reduced viscosity on concentration of the glucan in 0.5 mol/L NaOHaqueous solutions with or without urea showed two turning points corresponding to the dynamic contact concentration c_s andthe overlap concentration c~* of the polymer. The values of c_s and c~* were found to be 1×10^(-3) g cm^(-3) and 1.1×10^(-2) g cm^(-3),respectively, for L-FV-Ⅱ in 0.5 mol/L NaOH aqueous solutions. The two critical concentrations of L-FV-Ⅱ in 0.5 mol/LNaOH aqueous solutions were also found to be 1.2×10^(-3) g cm^(-3) fbr c_s and 9.2×10^(-3) g cm^(-3) for c~* from the concentrationdependence of phenanthrene fluorescence intensities. The overlap concentration c~* of L-FV-Ⅱ in 0.5 mol/L NaOH aqueoussolutions was lower than that of polystyrene with same molecular weight in benzene, owing to the fact that polysaccharidetends to undergo aggregation caused by intermolecular hydrogen bonding. A normal viscosity behavior of L-FV-Ⅱ in 0.5 mol/L urea/0.5 mol/L NaOH aqueous solutions can still be observed in an extremely low concentration range at 25℃.
文摘目的：探讨血浆（1‐3）‐β‐D葡聚糖检测对艾滋病（AIDS）患者合并播散性马尔尼菲青霉菌病（DPsM ）的诊断价值，为临床提供早期治疗依据。方法回顾性研究2010年4月－2014年7月174例 AIDS住院患者，分为观察组82例为临床确诊合并播散性马尔尼菲青霉菌病，对照组92例为无机会性感染，运用M B‐80微生物快速动态检测系统进行血浆（1‐3）‐β‐D葡聚糖检测（G试验），比较两组血浆（1‐3）‐β‐D葡聚糖水平，绘制受试者工作特征（ROC）曲线，确定血浆（1‐3）‐β‐D葡聚糖水平诊断播散性马尔尼菲青霉菌病的最佳诊断值。结果观察组和对照组血浆（1‐3）‐β‐D葡聚糖检测浓度中位数分别为198．0 pg／ml和24．0 pg／ml ，两组比较差异有统计学意义（P＜0．05）；ROC曲线分析结果显示，血浆（1‐3）‐β‐D葡聚糖用于诊断播散性马尔尼菲青霉菌病的最佳诊断值为75 pg／m l ，曲线下面积（A U C ）为0．843（95％ C I 0．784～0．903，P＜0．05），灵敏度、特异性、阳性预测值、阴性预测值分别为74．40％、84．80％、81．30％和78．79％。结论血浆（1‐3）‐β‐D葡聚糖检测具有早期诊断播散性马尔尼菲青霉菌病的临床应用价值，最佳诊断值为75 pg／m l。
文摘分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露聚糖和蛋白质这两种成分。但先用c(NaOH)=1 0mol/L的水溶液提取,再用w(CH3COOH)=4%的醋酸溶液处理时,产品为高纯度的(1→3) β D 葡聚糖。此结论由傅立叶红外光谱和核磁共振碳谱得到进一步的证实。接着从其水解机理上阐述了产生上述两种不同结果的原因,从而说明了酸碱法是从啤酒酵母中提取(1→3) β D 葡聚糖的理想途径。
