鸡贫血病雏鸡ND免疫后局部免疫组织抗体生成细胞变化

对感染鸡贫血病毒（ＣＡＶ）雏鸡新城疫（ＮＤ）疫苗免疫及其强毒攻击后局部免疫组织——盲肠扁桃体和哈德尔腺的ＩｇＡ、ＩｇＧ和ＩｇＭ抗体生成细胞数量的动态变化进行了检测。结果发现,ＣＡＶ感染雏鸡ＮＤ免疫后７、１４、２８ｄ及新城疫强毒（ｖＮＤＶ）攻击后,上述免疫组织的三种抗体生成细胞数量均不同程度地低于未感染ＣＡＶ的ＮＤ免疫对照雏鸡。其中盲肠扁桃体弥散区的ＩｇＡ减少最为明显。表明ＣＡＶ感染雏鸡消化道和呼吸道局部免疫组织对新城疫疫苗的体液免疫应答功能降低。新城疫强毒攻击后ＣＡＶ感染ＮＤ免疫雏鸡的免疫保护率也明显低于未感染ＣＡＶ的免疫对照雏鸡。     

鸽新城疫病毒毒价的血凝价,ELD50和TCID50值相关性比较

本文比较了用血凝反应（ＨＡ）,在鸡胚成纤维细胞上的ＴＣＩＤ５０及用发育鸡胚做ＥＬＤ５０来测定鸽新城疫病毒（ＮＤＶ）毒价的相关性。结果表明,鸽ＮＤＶ毒价的ＴＣＩＤ５０和ＥＬＤ５０的值基本相同。ＨＡ滴度虽然与ＴＣＩＤ５０值有一定的相关性,但远不如ＴＣＩＤ５０准确。接种病毒后死亡鸡胚的新鲜尿囊液经冻融后,其中鸽ＮＤＶ的ＨＡ滴度和ＴＣＩＤ５０均逐渐下降。每经一次冻融,毒价几乎减少５０％。     

鄂温克旗退化草地现状与草业的可持续发展

通过对鄂温克旗天然草地资源23年(1974～1997)的动态分析,阐明了自治旗天然草地退化的现状、特征、趋势和导致草地退化的主要原因,并提出了相应的可持续发展措施.     

A型流感病毒PB1-F2蛋白与蛋白激酶R相互作用研究

为研究A型流感病毒的重要毒力因子PB1-F2对蛋白激酶R(PKR)的调控机制,通过纯化GST-PB1-F2融合蛋白,利用GST pull-down试验证实了PB1-F2与PKR发生相互作用;采用免疫荧光试验进一步验证了二者的相互关系;实时荧光定量PCR表明PB1-F2能负调控PKR及IL-6的mRNA水平;采用siRNA干扰PKR基因的表达后,PB1-F2抑制IL-6的mRNA转录作用更显著。进一步运用蛋白免疫印迹方法检测了PB1-F2对PKR及其底物eIF-2α蛋白磷酸化水平的影响,显示过表达PB1-F2后,PKR及eIF-2α的磷酸化表达水平明显下调。本研究表明PB1-F2与PKR相互作用而抑制PKR磷酸化活化,并通过PKR调控IL-6的表达,为探索PB1-F2的未知生物学功能提供了重要信息。     

Effects of Yeast Culture on Growth Performance,Meat Quality and Intestinal Microflora of Broilers

The experiment was conducted to study the effects of yeast culture on growth performance, meat quality and intestinal microflora of broilers. A total of 432 1-day-old AA commercial broiler chicks with initial body weight of (41.73±0.15)g were randomly divided into 4 groups with 6 replicates per group and 18 broilers per replicate,receiving diets supplemented with 0,0.1%,0.2% and 0.3% yeast culture, respectively. The trial lasted for 42 days which was divided into two periods with 1 to 21 d and 22 to 42 d,respectively.The feed intake,body weight,death and culling rate were recorded in each period. At the end of the experiment,1 chickens in each replicate with the weight close to the average value were slaughtered after fasting for 12 h. The slaughter performance and intestinal microflora counts were determined.The results showed that compared with control group,the supplementation of 0.2% and 0.3% yeast culture significantly increased the body weight at 42 d and the average daily gain (ADG) during the whole trial (P< 0.05).The diet supplemented with 0.2% yeast culture significantly improved the ADG,decreased the F/G of broilers during 22 to 42 d (P< 0.05),and it also significantly increased the average daily feed intake (ADFI) and ADG (P< 0.05),decreased the F/G of the whole period (P< 0.05).Moreover,the supplementation of 0.2% yeast culture significantly decreased the drip loss of meat and the count of Escherichia coli (P< 0.05),and significantly increased the count of Bifidobacterium(P< 0.05). In summary, the supplementation of 0.2% yeast culture could significantly improve the growth performance and the muscle quality of broilers.The intestinal microflora in broiler cecum were effectively optimized after inclusion of yeast culture in the study.     

生长猪棉籽粕消化能的评定及估测模型研究

本试验通过采集我国棉花主产区棉籽粕样品,分析棉籽粕常规成分,测定其生长猪消化能(DE),建立棉籽粕常规成分与生长猪DE之间的关系。采用15%和20%替代比例的套算法,分别测定生长猪棉籽粕DE,探讨套算法中不同替代比例对DE的影响。试验选用体重[(37.2±1.8)kg]相近的"杜×长×大"三元杂交健康阉公猪18头,采用3个6×6拉丁方试验设计,全收粪法分别测定9个棉籽粕样品DE,并将棉籽粕常规成分与DE进行相关分析,建立回归方程,比较2个不同替代比例的套算法测定的DE。结果表明:本次试验所测定棉籽粕DE的加权平均值(风干基础,干物质90.41%)为9.94 MJ/kg;长江流域棉区平均值(风干基础,干物质89.72%)为9.96 MJ/kg;黄河流域棉区平均值(风干基础,干物质89.86%)为9.23 MJ/kg;西北内陆棉区平均值(风干基础,干物质91.30%)为10.61 MJ/kg。推荐DE预测模型(干物质基础):DE(MJ/kg)=-14.38+0.557×总能+0.320 95×粗蛋白质-0.012 68×中性洗涤纤维(R2=0.72)。套算法中的2个不同替代比例(15%和20%)对DE影响较小。     

Improvement of wood properties by composite of diatomite and “phenol-melamine-formaldehyde” co-condensed resin

We improved the overall performance of fast-growing poplar by utilizing a low-cost, effective and simple method. The fast-growing poplar was modified by a vacuum-pressure impregnation method with three...     

施用有机肥对凯特杏果实品质和产量的影响

以12年生的凯特杏为试材,连续3年进行了施有机肥处理对其果实品质和产量的影响试验,结果表明,在凯特杏果园施肥管理中应注重有机肥施入,即每667 m~2施2 800kg有机肥,可保证果实生长发育,增加果园产量和品质。     

SS4G型电力机车跳主断路器无显示原因分析及处理

随着经济的不断发展,需要运输的货物变得越来越多,所以我国设计出了SS4G型电力机车.虽然说SS4G型电力机车的创造在一定程度上减轻了很多方面的运输压力,但是SS4G型电力机车在使用的过程中也出现了很多问题,很大程度上影响了电力机车的使用.文章针对SS4G型电力机车出现的故障中跳主断路器无显示的问题进行研究,从而提出应对的措施,这样才能最大限度上保证SS4G型电力机车的使用.     

高职院校专业群建设的意义及内容

高职院校专业群建设具有十分重要的意义,它是高职院校发展的核心工作、实现就业导向的保证、高职课程改革成功的保障,同时也是专业建设的复杂性需要的新指导方法.其内容主要包括适应产业结构调整,系统培养技术技能型人才、提高专业的办学质量,增强办学活力、发挥专业带头人作用,促进专业建设的可持续发展等.