杀菌型乳酸菌饮料的模糊数学综合感官评判方法

通过对市场上流行的5种杀菌型乳酸菌饮料的焦糖味、果味、发酵味、甜味、酸味、涩感的感官评定,采用组合赋权法得出杀菌型乳酸菌饮料焦糖味、果味、发酵味、甜味、酸味、涩感的质量权重.对5种杀菌型褐色乳酸菌饮料各指标以权重,然后结合模糊数学综合评判方法,得出模糊关系曲线.结果表明:5种杀菌型乳酸菌饮料的整体感官排序为:样品5＞样品2＞样品4=样品l＞样品3,与一般排序法所得结果样品2＞样品4=样品1＞样品5＞样品3相比较稍有不同.因此,模糊数学综合评判方法比常用的排序法更科学、合理、客观.     

西藏兔病毒性出血症的研究--病原鉴定及疫苗免疫效力试验

１９９４年６￣７月,西藏林芝地区家兔大批急性死亡同,经过流行病学调查,临诊断症状观察,病理剖检等结果与兔病毒性出血症特征相符。进一步作病毒学检查表明,病变组织超薄发切片经电子显微镜观察发现有大量直径约３０ｎｍ的球状裸听病毒粒子,自然病死兔肝组织匀交涉 清能凝集入）型红细胞,而且血凝兔出血症病毒阳性抗血清所抑制,致病性试验结果表明,该病毒对兔有很强的致病性;用西藏自然病死兔肝组织匀浆试制的矩形疫苗兔     

Vero E6细胞酵母双杂交cDNA文库的构建及鉴定

To seek out proteins which interact with structural proteins of porcine epidemic diarrhea virus （PEDV） in Vero E6 cells and study the mechanisms of viral infection.We created a Vero E6 cDNA yeast hybrid library. The total RNA of Vero E6 was extracted using Trizol method, and double strands cDNA was synthesized by SMART technique. We created a Vero E6 cDNA library by using homologous recombination in yeast. The results showed that the titer of cDNA library was 9.7×10⁸ CFU with the average of inserted fragments about 1.6 kb, and the recombination rate was 87%. These data indicated that the yeast two-hybrid cDNA library of Vero E6 was successfully constructed and might be useful for screening the host proteins interacting with structure protein of PEDV.     

Cloning and Sequence Analysis of Major Histocompatibility Complex Ⅰ Gene from Goose F1 of Fast-growth Lines

According to the multiple alignments identified major histocompatibility complex Ⅰ (MHC Ⅰ) gene conserved sequence registered in GenBank from the family ducks (Anatidae) anser waterfowl, a pairs of specific primers for the fragments of MHCⅠgene of goose F1 from fast-growth lines were designed and synthesized by Primer Premier 5.0. Using the genome DNA of goose F1 from fast-growth lines, the target gene fragment was obtained by PCR. To conduct sequencing of the fragments of MHCⅠgene of goose F1 from fast-growth lines and make sequence alignment and analysis of protein structure and function by bioinformatics, and research the characteristics of MHCⅠgene of goose F1 and the physicochemical properties of the protein. Bioinformatics was analyzed the nucleic acid data, deduced amino acid sequence and phylogenetic trees. The result of sequence analysis showed that the fragments of MHCⅠgene of goose F1 from fast-growth lines was 1036 bp in length, which coded 96 amino acids polyprotein. The homology were 93% and 83% with MHC Ⅰ gene and coding sequence of Wulong goose in NCBI respectively. There were 72 different bases sequence and 16 amino acids change. There also was higher homology with other poultry, and existed genetic relationship of Siji goose > chickens > ducks.The homology segment sequences corresponding to the fragments of MHCⅠ gene of goose F1 coded 96 amino acids protein, which molecular weight, PI, positively or negatively charged amino acid, estimated half-life, instability index, aliphatic index and average hydrophobicity were 11.342 ku, 5.32, 14, 17, 2.8 h, 34.92, 42.81, -1.066, respectively, and appeared 9 B cell epitopes, but contained no signal peptide. These results indicated that the protein for hydrophilic non-secreted proteins, had the high immunogenicity. In addition, The protein structure study indicated that alpha-helix, beta-sheet, beta-turn and random coil were 31.25%,16.67%, 14.58% and 37.50%, respectively. There existed amino terminal domain and carboxyl terminal domain in the tertiary structure. Therefore, MHC gene had significant difference between species and populations of individuals by the pathogen pressure in environment, and there were the interaction between polymorphism of MHC molecules and the diversity of antigenic peptide. MHC determined the differences of individual susceptibility to disease, and could be treated as a candidate gene for disease resistance.     

中度盐碱化草地混播牧草替代玉米青贮对绵羊生产性能的影响

为研究中度盐碱化草地混播牧草对绵羊采食量、日增重和屠宰性能的影响,试验选用24只3月龄、体重(23.1±0.62) kg的德国肉用美利奴杂交一代绵羊,随机分为4组,对照组饲喂精料补充料十玉米(Zea mays)青贮,处理Ⅰ,Ⅱ和Ⅲ组在对照日粮基础上分别以中度盐碱化草地混播牧草(披碱草(Elymus dahuricus)、碱茅(Puccinellia distans)和沙打旺(Astragalus adsurgens))替代1/3,2/3和3/3玉米青贮,每只羊精料补充料日喂600 g,粗饲料自由采食.结果表明:处理Ⅰ,Ⅱ和Ⅲ组的有机物、干物质、酸性洗涤纤维、中性洗涤纤维采食量均显著高于对照组(P＜0.05);处理Ⅰ和Ⅱ组的日增重虽略高于对照组,但差异不显著;处理Ⅱ和Ⅲ组的饲料转化率显著高于对照组;各处理组绵羊屠宰体重、胴体重、屠宰率、净肉率、胴体出肉率、肉骨比、眼肌面积均较对照显著提高(P＜0.05).因此,中度盐碱化草地混播牧草替代玉米青贮可以增加绵羊的采食量,提高绵羊的屠宰性能,并以处理Ⅰ和Ⅱ组的效果较理想.     

24％溴虫腈·辛硫磷乳油对家蚕残毒试验

桑园治虫用药一直移用农田农药,安全性差,家蚕中毒事故频发;近年虽有一些桑园专用农药推出,但由于数量少,使用频率高,促成了害虫耐药性迅速提高,造成多种药物防效明显下降;开发桑园专用新农药,对桑园害虫控制和抗性治理都有积极意义。     

裂区设计下分析影响欧洲菊苣产量的因素

在裂区设计下,分析影响欧洲菊苣（Cichorium intybus cv.Europ）产量的7个因素,结果表明：播种季节对株高、产量有显著性影响;播种方式对株高、茎粗、密度、盖度、产量5个指标均有显著影响。进一步通过因子分析得出欧洲菊苣产量最佳组合为撒播、密度在50～59株·m^-2、盖度为94%～100%。     

桦木酸抑制地塞米松诱导脾淋巴细胞凋亡的作用

研究桦木酸对脾淋巴细胞凋亡的影响。以地塞米松建立小鼠体外脾淋巴细胞凋亡模型,利用倒置显微镜、荧光显微镜和电子透射显微镜观察细胞形态和亚细胞结构,琼脂糖凝胶电泳观察DNA的裂解,流式细胞术测定细胞凋亡率,检测华木酸对Dex介导的小鼠脾淋巴细胞凋亡的影响。结果表明,2.5μmol Dex可使脾淋巴细胞凋亡明显增加,染色质发生边聚、浓缩、凋亡小体等典型的凋亡特征,桦木酸可明显降低地塞米松引起的脾淋巴细胞凋亡。提示桦木酸对地塞米松诱导的淋巴细胞凋亡具有预防性保护作用。     

PRLR基因外显子10多态性与西农萨能奶山羊产奶性能的相关分析

设计4对引物,采用PCR—SSCP技术检测催乳素受体（PRLR）基因外显子10在西农萨能奶山羊群上的单核苷酸多态性,同时研究该基因对其产奶性能的影响。结果表明：引物P2、P3与P4扩增片段具有多态性,P1的扩增片段不存在多态性。应用P2扩增片段,在西农萨能奶山羊中仅检测到AA和AB基因型,纯化测序表明AA与AB基因型相比有2处突变,C27T的突变没有导致氨基酸变化,第189处的碱基缺失导致氨基酸由组氨酸变为酪氨酸和苏氨酸。AA和AB基因型之间产奶量的最小二乘均值差异显著（P〈0．05）,AA基因型在各胎次产奶量和平均产奶量等指标上均高于AB基因型,其中第3胎的产奶量达到显著水平（P〈0．05）;应用R扩增片段,在西农萨能奶山羊中检测到3种基因型（CC、CD、DD）,纯化测序表明CC与DD基因型相比有2处突变（C103A和T106C）,分别导致氨基酸由赖氨酸变为苏氨酸、苏氨酸变为异亮氨酸;3种基因型之间产奶量的最小二乘均值差异不显著（P〉0．05）。应用P。扩增片段,在西农萨能奶山羊中也只检测到EE和EF基因型,纯化测序表明EE与EF基因型相比有1处突变（A114G）,该突变导致氨基酸由蛋氨酸变为缬氨酸;EE和EF基因型之间产奶量差异显著（P〈0．05）。EE基因型的个体各胎次产奶量均比EF型高,其中在第3、4胎产奶量和前4胎平均产奶量3项指标上都达到显著水平（P〈0．05）。研究结果提示：PRLR基因对奶山羊产奶量有显著影响,因此认为PRLR基因外显子10位点可作为奶山羊高产奶量的标记辅助选择的有效分子标记。     

REV感染肉种鸡后动态病理学观察与抗原分布及检测

用网状内皮组织增生病病毒(REV)人工接种1日龄肉种鸡,定期剖杀,通过病理组织学观察病变特征及肿瘤的发生发展;用免疫组化、PCR检测抗原与病毒在体内各器官的分布规律;超薄切片观察肿瘸细胞、病毒的形态.结果显示,肝脏、脾脏、胸腺、法氏囊较早出现明显的肿瘤增生灶,在这些器官内免疫组化阳性信号出现最早,且信号最强,在5周龄时,心肌、腺胃、肺、肾、骨髓等器官才开始出现阳性信号,但呈中度的阳性反应,9周龄后阳性信号开始减弱.肝脏、脾脏、胸腺、法氏囊、骨髓扩增出REV的LTR基因片段,超薄切片显示病毒多分布在胞浆内和细胞间隙内.研究发现病变明显的组织中,阳性反应较强,肿瘤细胞增生明显,即强阳性反应的组织器官易形成肿瘤转移灶及肿瘤结节,同时,抗原最早出现在这些器官说明其中可能存在REV的靶细胞.虽然阳性信号在腺胃出现较晚,但90%以上的腺胃肿大说明腺胃也是REV的主要侵害器官.