搜索结果: 151-165 共查到“知识库 生物化学”相关记录3417条 . 查询时间(1.64 秒)
本项目研究了七种抑制剂(分别为亚硫酸钠、明矾、O-异抗坏血酸、EDTA-2Na、CaCl2、多聚磷酸钠、柠檬酸亚锡二钠)对橄榄多酚氧化酶和过氧化物酶活力的影响,并采用两段模型分析了高温处理对橄榄果实多酚氧化酶(PPO)和过氧化物酶(POD)的钝化动力学。结果表明,橄榄中酚类化合物氧化分解与POD和PPO活性有关,在特定的环境条件下,O-异抗坏血酸和柠檬酸亚锡二钠抑制橄榄PPO酶和POD酶活性效果最...
以精炼羊脂为原料,利用脂肪酶酶解以得到小分子脂解产物。选取底物浓度、加酶量、酶解时间为单因素,脂解率为响应指标进行单因素试验,并在此基础上采用Box-Behnken响应面法设计优化羊脂酶解工艺,且对不同酶解程度羊脂特征性挥发成分进行顶空固相微萃取/气相色谱-质谱(SPME/GC-MS)分析,确定酶解程度与挥发物之间的关系。结果表明,在酶解温度为50 ℃,pH为6.5时,最佳酶解体系参数为:底物质量...
以柴达木大肥菇(Agaricus bitorquis(Quél.)Sacc)子实体为原料,基于超声波辅助提取手段,采用单因素、响应面优化试验针对超声波提取多糖工艺参数进行优化,结果表明:通过响应面优化提取条件,确定柴达木大肥菇粗多糖提取的最佳工艺为超声功率126 W,料液比1:36 g/mL,提取时间为15 min。采用在此提取工艺条件下提取获得的粗多糖进行动物评价实验,通过小鼠常压耐缺氧、亚硝酸...
以蒸馏水、无水乙醇为溶剂结合超声波辅助及传统煎煮方法对艾叶进行提取,测定各提取物总黄酮和总酚含量、自由基清除能力以及艾叶提取物对黄嘌呤氧化酶(Xanthine Oxidase,XOD)的抑制作用,并选取抑制效果较好的艾叶醇提物,利用动物实验,测定小鼠血清尿酸(UA),肌酐(Scr),尿素氮水平(BUN),肝脏XOD活性,研究艾叶提取物对高尿酸血症小鼠的降尿酸的作用。结果表明:总黄酮和总酚含量:醇提...
以蒸馏水、无水乙醇为溶剂结合超声波辅助及传统煎煮方法对艾叶进行提取,测定各提取物总黄酮和总酚含量、自由基清除能力以及艾叶提取物对黄嘌呤氧化酶(Xanthine Oxidase,XOD)的抑制作用,并选取抑制效果较好的艾叶醇提物,利用动物实验,测定小鼠血清尿酸(UA),肌酐(Scr),尿素氮水平(BUN),肝脏XOD活性,研究艾叶提取物对高尿酸血症小鼠的降尿酸的作用。结果表明:总黄酮和总酚含量:醇提...
研究马立克病毒引发肿瘤的发生、发展过程中,热休克蛋白(heat shock proteins,HSPs)转录表达水平、组织细胞内定位与肝病理组织学损伤之间的相关性,为进一步阐述HSPs的生物学作用奠定基础。通过人工感染建立鸡MD肿瘤模型,定期剖杀试验鸡,采集肝组织,利用组织学、免疫组织化学、荧光定量RT-PCR及ELISA方法,检测肝病理组织学损伤、HSPs组织细胞内定位以及HSPs转录、表达水平...
旨在比较研究抗菌肽sublancin与黄芪多糖对环磷酰胺(cyclophosphamide,CTX)诱导的免疫抑制小鼠的免疫功能的调节作用。试验选取60只4~6周龄健康雌性BALB/c小鼠,随机分为6个处理组。正常对照组:第1-3天,腹腔注射生理盐水;第4-10天,灌胃生理盐水。其余五个处理组:第1-3天,腹腔注射CTX(80 mg·kg-1);第4-10天,阴性对照组:灌胃生理盐水;低浓度抗菌肽...
新城疫病毒M蛋白核定位信号突变降低病毒的致病性
新城疫病毒 M蛋白 核定位信号 致病性
2019/3/8
本研究旨在探讨M蛋白核定位信号(NLS)突变对新城疫病毒(NDV)致病性的影响。将M蛋白NLS突变体病毒和亲本病毒分别感染4周龄SPF鸡,观察鸡的临床症状和病理变化,检测鸡喉头和泄殖腔排毒情况以及不同组织中的病毒含量,并对免疫器官进行显微病变观察,以及分析免疫器官中M蛋白的表达量和相关细胞因子的表达变化。结果表明,鸡感染亲本病毒后产生典型的新城疫临床症状和病理变化,喉头和泄殖腔持续排毒且排毒量高,...
为了研究PRRSV M蛋白的ITIM基序对IFN-β产生的激活机制,以PRRSV Hn-1/06毒株cDNA为模板扩增ORF6基因片段,分别构建了重组质粒pcDNA3.0-GP6、pcDNA3.0-GP6△ITIM(缺失ITIM基序)。将重组质粒分别转染Marc-145细胞,用荧光定量PCR方法检测TRIF、MyD88、TRAF6、IRF3、IRF7、NF-κB和IFN-β的mRNA转录水平;结果...
Effects of selenium on selenoprotein synthesis and antioxidant parameters of bovine mammary epithelial cells
trace element dairy cows glutathione peroxidase thioredoxin reductase antioxidant function
2018/11/23
This study aimed to investigate the effects of selenium (Se) on the selenoproteins synthesis and antioxidant parameters of bovine mammary epithelial cells (BMECs). The experiment was conducted as a si...
Organic matter and crude protein digestibility predicted from nitrogen and fibre fractionation of festulolium hybrids
nitrogen fractions Cornell system nutritive value ruminant
2018/11/23
The objectives of the experiment were to study nitrogen fractions of the Cornell Net Carbohydrate and Protein System (CNCPS) and digestibility of organic matter (OMD) and crude protein (CPD) along wit...
Alternative polyadenylation and polymorphisms of 3'untranslated regions of bovine BBOX1 gene
candidate gene transcript variants meat quality carcass traits association analysis
2018/11/23
l-Carnitine, a key element in fatty acid metabolism and energy production, is biosynthesized from gamma-butyro-betaine by the catalysis of gamma-butyrobetaine hydroxylase (BBOX1). We cloned three diff...
Negative effect of phytase superdosing in laying hens
Hisex dietary calcium OptiPhos® performance
2018/11/23
Hisex hens, aged 24 weeks, were divided into 6 groups. Each group consisted of 4 cages with 10 hens per cage with dimensions and equipment meeting the EU directives. This 2 × 3 factorial experiment in...
Effects of zinc sources and levels on zinc bioavailability, blood parameters, and nutrient balance of male mink (Neovison vison)
zinc pectin oligosaccharides chelate nutrient digestibility relative bioavailability
2018/11/23
The objective of this study was to investigate the effects of different sources and levels of zinc (Zn) on nutrient digestibility, plasma metabolites, and relative Zn bioavailability in male mink. Ani...
Associations between gene polymorphisms, breeding values, and glucose tolerance test parameters in German Holstein sires
Bos taurus milk glucose metabolism DGAT1 GH1 GHR FASN OLR1 ABCG2
2018/11/23
The association between several gene polymorphisms, the estimated breeding values for milk performance traits, and glucose metabolism measured by the glucose tolerance test (GTT) in German Holstein si...