A type of high molecular weight bioactive polymers called exopolysaccharides(EPS)are produced by thermophiles,the extremophilic microbes that thrive in acidic environmental conditions of hot springs with excessively w...A type of high molecular weight bioactive polymers called exopolysaccharides(EPS)are produced by thermophiles,the extremophilic microbes that thrive in acidic environmental conditions of hot springs with excessively warm temperatures.Over time,EPS became important as natural biotechnological additives because of their noncytotoxic,emulsifying,antioxidant,or immunostimulant activities.In this article,we unravelled a new EPS produced by Staphy-lococcus sp.BSP3 from an acidic(pH 6.03)San Pedro hot spring(38.1℃)located in the central Andean mountains in Chile.Several physicochemical techniques were performed to characterize the EPS structure including Scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS),Atomic Force Microscopy(AFM),High-Performance Liquid Chromatography(HPLC),Gel permeation chromatography(GPC),Fourier Transform Infrared Spectroscopy(FTIR),1D Nuclear Magnetic Resonance(NMR),and Thermogravimetric analysis(TGA).It was confirmed that the amorphous surface of the BSP3 EPS,composed of rough pillar-like nanostructures,is evenly distributed.The main EPS monosaccharide constituents were mannose(72%),glucose(24%)and galactose(4%).Also,it is a medium molecular weight(43.7 kDa)heteropolysaccharide.NMR spectroscopy demonstrated the presence of a[→6)-α-d-Manp-(1→6)-α-d-Manp-(1→]backbone 2-O substituted with 1-α-d-Manp.A high thermal stability of EPS(287°C)was confirmed by TGA analysis.Emulsification,antioxidant,flocculation,water-holding(WHC),and oil-holding(OHC)capacities are also studied for biotechnological industry applications.The results demonstrated that BSP3 EPS could be used as a biodegradable material for different purposes,like flocculation and natural additives in product formulation.展开更多
目的探讨血清表面活性蛋白D(surfactant protein D,SP-D)、黏蛋白1(mucin 1,MUC1)、锌指蛋白A20(zinc finger protein A20,A20)水平对输血相关性急性肺损伤(transfusion-related acute lung injury,TRALI)患者临床预后的预测价值,以期...目的探讨血清表面活性蛋白D(surfactant protein D,SP-D)、黏蛋白1(mucin 1,MUC1)、锌指蛋白A20(zinc finger protein A20,A20)水平对输血相关性急性肺损伤(transfusion-related acute lung injury,TRALI)患者临床预后的预测价值,以期临床个体化干预提供参考。方法选取2020年3月—2025年3月河北省胸科医院收治的TRALI患者249例为研究对象,根据输血后30 d内预后情况,分别纳入预后良好组(178例)、预后不良组(71例)。比较2组一般临床资料及血清SP-D、MUC1、A20水平,Logistic回归分析血清SP-D、MUC1、A20水平对TRALI患者预后不良的影响因素,受试者工作特征(receiver operating characteristic,ROC)曲线分析血清SP-D、MUC1、A20水平单独及联合检测对预后不良的预测效能,并采用一致性分析进行外部验证。结果2组输血次数、发血至输血时间、过敏史、急性生理与慢性健康评分系统Ⅱ(acute physiology and chronic health evaluationⅡ,APACHEⅡ)评分比较,差异有统计学意义(P<0.05);预后不良组血清SP-D、MUC1、A20水平分别为(89.54±21.36)g/L、(22.97±5.14)kU/L、(14.53±1.96)mg/L,明显高于预后良好组的(78.61±18.05)g/L、(16.28±4.32)kU/L、(12.67±1.84)mg/L,差异有统计学意义(P<0.05);Logistic回归分析显示,输血次数、发血至输血时间、过敏史均是TRALI患者预后不良的影响因素(P<0.05),APACHEⅡ评分及血清SP-D、MUC1、A20均与TRALI患者预后不良显著相关(P<0.05);ROC分析显示,血清SP-D、MUC1、A20联合预测预后不良的曲线下面积(area under the curve,AUC)为0.904(95%CI:0.860~0.938),优于各指标单独预测价值(Z=2.507、3.016、3.042,均P<0.05),且外部验证显示,联合预测预后不良与临床实际的符合率为95.00%,Kappa值为0.870(95%CI:0.617~0.982)差异有统计学意义(P<0.05)。结论血清SP-D、MUC1、A20均是TRALI患者预后不良的独立影响因素,联合检测对预后不良具有较高预测价值,可作为TRALI患者预后的潜在预测因子,并可指导临床工作。展开更多
[Objectives]This study aimed to evaluate the detection sensitivity of Staphylococcus aureus in dairy products utilizing the chip digital PCR(cdPCR)technique.[Methods]Specific primers and probes were designed and synth...[Objectives]This study aimed to evaluate the detection sensitivity of Staphylococcus aureus in dairy products utilizing the chip digital PCR(cdPCR)technique.[Methods]Specific primers and probes were designed and synthesized based on the conserved sequence of the heat-resistant nuclease gene nuc of S.aureus.cdPCR was employed to detect S.aureus,and the sensitivity of this technique was systematically assessed in samples exhibiting low levels of contamination.[Results]cdPCR demonstrated precise quantification when the initial concentration of the sample enrichment solution was equal to or greater than 50 CFU/mL.The detection dynamic range extended across at least five orders of magnitude,with a minimum DNA detection limit of 0.2304 pg/μL.In artificially contaminated cheese samples,the method s lower limit of quantification for detecting S.aureus was 8×10^(2) CFU/g.Regression analysis demonstrated that the gene copy number concentration measured by cdPCR exhibited a strong linear correlation with bacterial contamination concentration across a broad range.[Conclusions]The cdPCR method developed in this study demonstrates high sensitivity and robust quantitative capabilities,offering a reliable technical approach for the precise detection of low-level S.aureus contamination in dairy products.展开更多
基金funded by FONDECYT Regular,Grant Number 1231917 by ANID,Govt.of Chile.
文摘A type of high molecular weight bioactive polymers called exopolysaccharides(EPS)are produced by thermophiles,the extremophilic microbes that thrive in acidic environmental conditions of hot springs with excessively warm temperatures.Over time,EPS became important as natural biotechnological additives because of their noncytotoxic,emulsifying,antioxidant,or immunostimulant activities.In this article,we unravelled a new EPS produced by Staphy-lococcus sp.BSP3 from an acidic(pH 6.03)San Pedro hot spring(38.1℃)located in the central Andean mountains in Chile.Several physicochemical techniques were performed to characterize the EPS structure including Scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS),Atomic Force Microscopy(AFM),High-Performance Liquid Chromatography(HPLC),Gel permeation chromatography(GPC),Fourier Transform Infrared Spectroscopy(FTIR),1D Nuclear Magnetic Resonance(NMR),and Thermogravimetric analysis(TGA).It was confirmed that the amorphous surface of the BSP3 EPS,composed of rough pillar-like nanostructures,is evenly distributed.The main EPS monosaccharide constituents were mannose(72%),glucose(24%)and galactose(4%).Also,it is a medium molecular weight(43.7 kDa)heteropolysaccharide.NMR spectroscopy demonstrated the presence of a[→6)-α-d-Manp-(1→6)-α-d-Manp-(1→]backbone 2-O substituted with 1-α-d-Manp.A high thermal stability of EPS(287°C)was confirmed by TGA analysis.Emulsification,antioxidant,flocculation,water-holding(WHC),and oil-holding(OHC)capacities are also studied for biotechnological industry applications.The results demonstrated that BSP3 EPS could be used as a biodegradable material for different purposes,like flocculation and natural additives in product formulation.
文摘目的探讨血清表面活性蛋白D(surfactant protein D,SP-D)、黏蛋白1(mucin 1,MUC1)、锌指蛋白A20(zinc finger protein A20,A20)水平对输血相关性急性肺损伤(transfusion-related acute lung injury,TRALI)患者临床预后的预测价值,以期临床个体化干预提供参考。方法选取2020年3月—2025年3月河北省胸科医院收治的TRALI患者249例为研究对象,根据输血后30 d内预后情况,分别纳入预后良好组(178例)、预后不良组(71例)。比较2组一般临床资料及血清SP-D、MUC1、A20水平,Logistic回归分析血清SP-D、MUC1、A20水平对TRALI患者预后不良的影响因素,受试者工作特征(receiver operating characteristic,ROC)曲线分析血清SP-D、MUC1、A20水平单独及联合检测对预后不良的预测效能,并采用一致性分析进行外部验证。结果2组输血次数、发血至输血时间、过敏史、急性生理与慢性健康评分系统Ⅱ(acute physiology and chronic health evaluationⅡ,APACHEⅡ)评分比较,差异有统计学意义(P<0.05);预后不良组血清SP-D、MUC1、A20水平分别为(89.54±21.36)g/L、(22.97±5.14)kU/L、(14.53±1.96)mg/L,明显高于预后良好组的(78.61±18.05)g/L、(16.28±4.32)kU/L、(12.67±1.84)mg/L,差异有统计学意义(P<0.05);Logistic回归分析显示,输血次数、发血至输血时间、过敏史均是TRALI患者预后不良的影响因素(P<0.05),APACHEⅡ评分及血清SP-D、MUC1、A20均与TRALI患者预后不良显著相关(P<0.05);ROC分析显示,血清SP-D、MUC1、A20联合预测预后不良的曲线下面积(area under the curve,AUC)为0.904(95%CI:0.860~0.938),优于各指标单独预测价值(Z=2.507、3.016、3.042,均P<0.05),且外部验证显示,联合预测预后不良与临床实际的符合率为95.00%,Kappa值为0.870(95%CI:0.617~0.982)差异有统计学意义(P<0.05)。结论血清SP-D、MUC1、A20均是TRALI患者预后不良的独立影响因素,联合检测对预后不良具有较高预测价值,可作为TRALI患者预后的潜在预测因子,并可指导临床工作。
基金Supported by Science and Technology Program of Inner Mongolia Autonomous Region"Research and Demonstration of Novel Molecular Biological Identification Technology for Multiple Source Components in Milk and Dairy Products"(2025YFSH0029).
文摘[Objectives]This study aimed to evaluate the detection sensitivity of Staphylococcus aureus in dairy products utilizing the chip digital PCR(cdPCR)technique.[Methods]Specific primers and probes were designed and synthesized based on the conserved sequence of the heat-resistant nuclease gene nuc of S.aureus.cdPCR was employed to detect S.aureus,and the sensitivity of this technique was systematically assessed in samples exhibiting low levels of contamination.[Results]cdPCR demonstrated precise quantification when the initial concentration of the sample enrichment solution was equal to or greater than 50 CFU/mL.The detection dynamic range extended across at least five orders of magnitude,with a minimum DNA detection limit of 0.2304 pg/μL.In artificially contaminated cheese samples,the method s lower limit of quantification for detecting S.aureus was 8×10^(2) CFU/g.Regression analysis demonstrated that the gene copy number concentration measured by cdPCR exhibited a strong linear correlation with bacterial contamination concentration across a broad range.[Conclusions]The cdPCR method developed in this study demonstrates high sensitivity and robust quantitative capabilities,offering a reliable technical approach for the precise detection of low-level S.aureus contamination in dairy products.
