【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡...【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡萄汁酵素最优接种发酵方式。进一步通过单因素试验及响应面试验,优化葡萄汁酵素最佳发酵工艺条件。【结果】植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵可以显著提高葡萄汁酵素中益生菌活菌数和DPPH清除率;植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵的最佳工艺条件为:按照1∶1比例接种,初始接种量5.00 lg CFU/mL、大豆蛋白胨添加量0.46%、34℃发酵18 h,植物乳杆菌Zhang-LL活菌数达6.60×10^(8)CFU/mL,马克斯克鲁维酵母M3活菌数达8.20×10^(7)CFU/mL,酵素DPPH清除率85.25%。【结论】乳酸菌与酵母菌协同发酵,在缩短发酵时间的同时还能达到较高的活菌数和DPPH清除率,可为葡萄汁酵素的工业化制备及后续多功能产品研发提供理论依据。展开更多
Streamers represent an important stage in the initiation of gap discharge. In this work, we used an eight-frame intensified charge-coupled device camera to capture the streamer development process when a lightning imp...Streamers represent an important stage in the initiation of gap discharge. In this work, we used an eight-frame intensified charge-coupled device camera to capture the streamer development process when a lightning impulse voltage of 95%–100% U50% was applied in a 3 m rod–plate gap and the streamer velocity was analyzed. Analysis of the observations shows that streamer velocity can be defined by three stages: rapid velocity decline(stage 1), rapid velocity rise(stage 2)and slow velocity decline(stage 3). The effects of electrode shape, applied voltage and gap breakdown or withstanding on streamer velocity were analyzed. The electrode with a larger radius of curvature will result in a higher initial velocity, and a higher voltage amplitude will cause the streamer to propagate faster at stage 3. Gap withstanding or breakdown has no obvious effect on streamer velocity. In addition, the experimental results are compared with previous results and the statistical characteristics of the primary streamer discharge are discussed.展开更多
BACKGROUND A rare autosomal recessive genetic disorder,3M syndrome,is characterized by severe intrauterine and postnatal growth retardation.Children with 3M syndrome typically exhibit short stature,facial deformities,...BACKGROUND A rare autosomal recessive genetic disorder,3M syndrome,is characterized by severe intrauterine and postnatal growth retardation.Children with 3M syndrome typically exhibit short stature,facial deformities,long tubular bones,and high vertebral bodies but generally lack mental abnormalities or other organ damage.Pathogenic genes associated with 3M syndrome include CUL7,OBSL1 and CCDC8.The clinical and molecular characteristics of patient with 3M syn-drome are unique and serve as important diagnostic indicators.CASE SUMMARY In this case,the patient displayed square shoulders,scoliosis,long slender tubular bones,and normal neurological development.Notably,the patient did not exhibit the typical dysmorphic facial features,relative macrocephaly,or growth retardation commonly observed in individuals with 3M syndrome.Whole exon sequencing revealed a novel heterozygous c.56681+1G>C(Splice-3)variant and a previously reported nonsense heterozygous c.3341G>A(p.Trp1114Ter)variant of OBSL1.Therefore,it is important to note that the clinical features of 3M syndrome may not always be observable,and genetic confirmation is often required.Additionally,the identification of the c.5683+1G>C variant in OBSL1 is notewor-thy because it has not been previously reported in public databases.CONCLUSION Our study identified a new variant(c.5683+1G>C)of OBSL1 that contributes to expanding the molecular profile of 3M syndrome.展开更多
文摘【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡萄汁酵素最优接种发酵方式。进一步通过单因素试验及响应面试验,优化葡萄汁酵素最佳发酵工艺条件。【结果】植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵可以显著提高葡萄汁酵素中益生菌活菌数和DPPH清除率;植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵的最佳工艺条件为:按照1∶1比例接种,初始接种量5.00 lg CFU/mL、大豆蛋白胨添加量0.46%、34℃发酵18 h,植物乳杆菌Zhang-LL活菌数达6.60×10^(8)CFU/mL,马克斯克鲁维酵母M3活菌数达8.20×10^(7)CFU/mL,酵素DPPH清除率85.25%。【结论】乳酸菌与酵母菌协同发酵,在缩短发酵时间的同时还能达到较高的活菌数和DPPH清除率,可为葡萄汁酵素的工业化制备及后续多功能产品研发提供理论依据。
基金supported by the Beijing Science Fund for Distinguished Young Scholars(No.JQ22009)National Natural Science Foundation of China(No.51977198)。
文摘Streamers represent an important stage in the initiation of gap discharge. In this work, we used an eight-frame intensified charge-coupled device camera to capture the streamer development process when a lightning impulse voltage of 95%–100% U50% was applied in a 3 m rod–plate gap and the streamer velocity was analyzed. Analysis of the observations shows that streamer velocity can be defined by three stages: rapid velocity decline(stage 1), rapid velocity rise(stage 2)and slow velocity decline(stage 3). The effects of electrode shape, applied voltage and gap breakdown or withstanding on streamer velocity were analyzed. The electrode with a larger radius of curvature will result in a higher initial velocity, and a higher voltage amplitude will cause the streamer to propagate faster at stage 3. Gap withstanding or breakdown has no obvious effect on streamer velocity. In addition, the experimental results are compared with previous results and the statistical characteristics of the primary streamer discharge are discussed.
文摘BACKGROUND A rare autosomal recessive genetic disorder,3M syndrome,is characterized by severe intrauterine and postnatal growth retardation.Children with 3M syndrome typically exhibit short stature,facial deformities,long tubular bones,and high vertebral bodies but generally lack mental abnormalities or other organ damage.Pathogenic genes associated with 3M syndrome include CUL7,OBSL1 and CCDC8.The clinical and molecular characteristics of patient with 3M syn-drome are unique and serve as important diagnostic indicators.CASE SUMMARY In this case,the patient displayed square shoulders,scoliosis,long slender tubular bones,and normal neurological development.Notably,the patient did not exhibit the typical dysmorphic facial features,relative macrocephaly,or growth retardation commonly observed in individuals with 3M syndrome.Whole exon sequencing revealed a novel heterozygous c.56681+1G>C(Splice-3)variant and a previously reported nonsense heterozygous c.3341G>A(p.Trp1114Ter)variant of OBSL1.Therefore,it is important to note that the clinical features of 3M syndrome may not always be observable,and genetic confirmation is often required.Additionally,the identification of the c.5683+1G>C variant in OBSL1 is notewor-thy because it has not been previously reported in public databases.CONCLUSION Our study identified a new variant(c.5683+1G>C)of OBSL1 that contributes to expanding the molecular profile of 3M syndrome.
