水基清防蜡剂YE-60的研制与应用

渤中25-1油田原油含蜡量高,C平台油井结蜡严重,导致清蜡作业频繁。为此,研发了一种非离子表面活性剂型水基清防蜡剂YE-60,首先通过合成反应获得YE型醇醚,合成条件：乙醇、烷基聚氧乙烯聚氧丙烯醚、酰胺基聚氧乙烯聚氧丙烯多嵌段醚摩尔比1：1.25：1.25,催化剂加入量相对单体总量的质量分数1.98%,反应温度75℃,反应时间3 h;然后将YE型醇醚与渗透剂乙二醇乙醚按照一定的质量比进行复配,得到最终产品YE-60。在100 mg/L加剂量下,YE-60对渤中25-1油田综合油样的防蜡率达到74.5%,洗蜡率达到64.1%。现场应用后,检泵和清蜡周期延长3倍以上,证明了其显著的清防蜡效果,具有较高的推广应用价值。（表6,参7）     

Genotypic Variation in Maize Shoot Biomass at Different Stages of Development

A diallel cross from nine early-maturing lines of maize was grown in northern Germany during 1981 and 1982 in order to study the genotypic variation of shoot biomass at early and late stages of development. Inbred lines had been chosen from breeding programmes for early and medium early cultivars. Nevertheless, the date of maturity varied between them which can have some influence on the correlation between plant parameters. Plants were harvested at the fourth and sixth leaf stages, at anthesis and at maturity. S.c.a. effects were highly significant for traits during the vegetative stage. G.c.a. effects were highly significant for traits of the mature plant including grain yield components. The ratio of g.c.a. to s.c.a. effects for shoot biomass was dominated throughout the growing season by s.c.a. effects. Hybrids from the diallel cross had a superior growth rate until the fourth leaf stage; thereafter, relative growth rates of lines and hybrids were similar for the average of both groups until maturity. The correlation of g.c.a. effects and s.c.a. effects between shoot biomass throughout the season revealed that no significant relationship existed between early and late stages. G.c.a. and s.c.a. effects for grain yield components, with the exception of hundred kernel weight, were negatively correlated with shoot biomass at an early stage while correlation was positive at maturity. This would probably make it a difficult task to improve shoot growth and grain yield components simultaneously through the season.     

Detection of β2-agonists in milk replacer

₂-Agonist drugs may be illegally used as growth promoters for feedlot calves, when mixed into milk replacer immediately before feeding. To check for the presence of clenbuterol, salbutamol and terbutaline in such food, an analytical system was established using a screening method based on two commercial qualitative competitive ELISA tests, with antibodies raised against the arylamino group and thet-butyl group. The extraction procedure was based on precipitation of the milk samples with acetonitrile followed by filtration. The absence of any significant interference by other substances in the filtrate allowed detection of ₂-agonist drugs in spiked samples at the lowest concentration having a repartitioning effect (50 ppb for clenbuterol, mabuterol and terbutaline, 500 ppb for salbutamol). In view of a false positive response with tetracycline in milk samples and a cross-reaction between clenbuterol and mabuterol, an HPLC-MS technique was developed which, after extraction and purification of the samples with SPE C18 Polar Plus, was able to confirm the presence of these drugs. The good recovery after extraction (ranging from 84% to 90.2%) and the low detection limit with this method (250 ng/ml for clenbuterol, mabuterol and terbutaline, and 2.5 µg/ml for salbutamol) allowed easy confirmation and simultaneous detection of the four ₂-agonists at the lowest concentrations at which they are used in adulterated milk for calves.Abbreviations B optical density of the sample - B maximal optical density in total absence of competition - %B/B ₀ percentage of inhibition - ELISA enzyme-linked immunosorbent assay - EIA enzyme immunoassay - HPLC-MS high-performance liquid chromatography-mass spectrometry - m/z mass to charge ratio - ppb parts per billion - ppm parts per million - SPE solid-phase extraction     

绞股蓝内生真菌JY25胞外多糖对蛋雏鸡生长性能和肠黏膜免疫功能的影响

试验旨在探讨绞股蓝内生真菌JY25胞外多糖(JY25P)对蛋雏鸡生长性能和肠黏膜免疫功能的影响。将300羽健康的1日龄三黄蛋雏鸡,随机分为5组(每组设3个重复,每个重复20羽):Ⅰ组为灌服无菌水的空白对照组;Ⅱ组、Ⅲ组和Ⅳ组分别为灌服0.04%、0.08%和0.12%JY25P的试验组;Ⅴ组为灌服0.08%黄芪多糖的阳性对照组。结果表明:1)与Ⅰ组相比,Ⅳ组蛋雏鸡平均日增重显著提高了15.86%(P0.05),料重比极显著降低了24.13%(P0.01)。2)与Ⅰ组相比,试验各阶段,Ⅲ组、Ⅳ组、Ⅴ组均能显著提高蛋雏鸡血清中新城疫抗体效价(P0.05)。3)与Ⅰ组相比,在15日龄和20日龄,Ⅳ组可以极显著增加肠黏膜白细胞介素-4(IL-4)、干扰素-γ(IFN-γ)含量(P0.01),而对分泌型免疫球蛋白A(SIg A)和IFN-γ/IL-4的影响不显著(P0.05)。结果提示:灌服0.12%JY25P能改善蛋雏鸡的生长性能,提高特异性新城疫抗体效价,增强非特异性肠黏膜IL-4和IFN-γ的分泌,同时维持机体的免疫平衡,因此,该多糖具有较好的应用前景。     

转基因大豆中外源基因g10evo-epsps的qPCR检测方法的建立和验证

耐除草剂基因g10evo-epsps在我国转基因农作物研发中常常被用作目标性状基因或筛选标记基因,因此可作为转基因成分检测的重要筛查基因,但目前缺少相应的检测方法.本研究旨在建立g10evo-epsps基因特异性的实时荧光定量PCR(qPCR)检测方法,从而为转基因大豆的监测提供一种稳定可靠的方法体系.本研究基于转基因...     

口蹄疫感染性克隆疫苗的发展前景

口蹄疫是一种严重威胁畜牧业发展的重要传染病,目前世界上许多国家和地区都有该病的流行与发生。开展新型口蹄疫疫苗的研究一直是口蹄疫防制技术的一项重要内容。鉴于传统疫苗所存在的诸多缺点,人们先后研制开发了口蹄疫的第二代基因工程苗和第三代基因疫苗,这些新型疫苗都具有一定的优越性,显示出进一步发展的潜力。文章着重讨论了在感染性cDNA的基础上所构建的一类新型基因疫苗-感染性克隆疫苗及其发展前景。感染性克隆疫苗不仅继承了以往基因疫苗的许多优点,而且克服了其表达量低,免疫效果不理想的缺点,为新型疫苗的研制提供了一种新的思路。     

流产型布鲁菌Omp10、Omp25蛋白的表达纯化与鉴定

获得高纯度具有生物学活性的重组布鲁菌Omp10、Omp25融合蛋白,并进行抗原性的分析。将用PCR扩增出的布鲁菌Omp10、Omp25基因片段分别克隆到原核表达载体pET-32α中,构建pET-32α-Omp10/Omp25原核表达质粒。将其转入大肠杆菌BL21（DE3）PlysS中,用IPTG诱导表达,经HisTrap HP亲和层析柱分离纯化,分别用Western-blot和间接ELISA检测产物的抗原性。基因测序及酶切鉴定证明pET-32α-Omp10/Omp25原核表达载体构建成功。SDS-PAGE表明,Omp10、Omp25融合蛋白均以包涵体的形式在大肠杆菌中高效表达。经过包涵体的变性、复性及亲和层析纯化,成功获得了大小分别为34 000和44 000的融合蛋白,与预测的相对蛋白分子质量一致。Western和间接ELISA试验证明纯化的Omp10、Omp25融合蛋白能被免疫的牛布鲁菌阳性血清所识别。结果表明,成功获得了布鲁菌Omp10、Omp25融合蛋白,且均具有一定的免疫原性,通过血清学反应证实,Omp10、Omp25蛋白为布鲁菌病临床诊断试剂盒的研制奠定了基础。     

乳牛布鲁氏菌病PCR诊断试剂盒的实验室评估

对前期研制的布鲁氏菌omp25基因-PCR试剂盒的保存期、特异性和可重复性进行了测定，并应用该试剂盒对采自宁夏、甘肃、内蒙古、山西、黑龙江、新疆省（区）的98头血清凝集试验（SAT）阳性乳牛的6批98份乳样和350头SAT阴性乳牛的2批350份乳样进行了检测。检测结果显示，PCR试剂盒与SAT的阳性符合率为100％（98／98），阴性符合率为97．71％（342／350）；从SAT阴性乳牛的乳样中。用PCR试剂盒检出8份阳性，表明其敏感性高于SAT；对2株田间野毒Brgs和Br-nmg株进行了克隆与测序，二者与标准菌株序列的同源性分别为99．8％和100％。试验结果证实，本试剂盒的可重复性良好，特异性较高，-20℃下的有效保存期为5个月。     

外周血中CD4+、CD8+T、CD4+CD25+Treg在绵羊接种布鲁氏菌M5-90弱毒疫苗后的动态变化

为研究绵羊接种布鲁氏菌弱毒M5-90株后外周血中CD4+、CD8+T、CD4+CD25+Treg细胞的动态变化规律,本研究选择11只健康绵羊,每10 d免疫一次,共免疫3次,分别在免疫前、免疫后10d、20 d、30 d利用流式细胞术检测外周血中CD4+、CD8+T、CD4+CD25+Treg淋巴细胞亚群.在免疫后的第20 d,CD4+T、CD8+T细胞百分含量达到最高水平(P＜0.05)后均缓慢下降;在第10d,CD4+CD25+Treg细胞缓慢升高,至20 d、30 d均显著升高(p＜0.05);在布鲁氏菌M5-90疫苗免疫应答过程中CD4+CD25+Treg细胞参与了机体的免疫反应调控,对CD4+T、CD8+T淋巴细胞的比例进行调节,并且维持CD4+/CD8+比值稳定,起到平衡Th1/Th2细胞间反应的作用.     

含异常棉基因棉纤维品质及超分子结构遗传效应

通过对３个含有异常棉血缘的陆地棉高强纤维种质系和４个推广品种的纤维品质和纤维超分子结构分析表明，纤维比强度越高，纤维微原纤角越小，取向度越高，而与成熟纤维的结晶度关系不密切。４×３的不完全双列杂交分析表明，纤维品质和纤维超分子结构参数的基因型方差（除结晶度外）都达显著或极显著水平，对基因型方差进一步分解表明，母本的纤维比强度、长度、取向度和微原纤角的一般配合力均方达显著或极显著水平，其中泗棉３号的一般配合力最高。仅纤维比强度的特殊配合力均方达显著水平。纤维比强度以泗棉３号×７２３５为最高。Ｆ１与双亲均值的相关分析结果表明难以根据组合的中亲值来预测其杂交组合Ｆ１的表现。