肺组织中的NOS在肉鸡腹水症发生发展中的变化

研究利用β-NADPH-d组织化学染色法检测一氧化氮合酶（Nitric oxide synthase,NOS）在正常肉鸡、亚临床腹水鸡和腹水鸡肺组织中的分布和活性变化，结果显示，在正常肉鸡肺组织中，气道上皮和肺大，中血管内皮出血NOS阳性染色，而外径小于100μm的小血管却很少见阳性染色；腹水鸡肺内大，中血管内皮着色较正常肉鸡深，血管平滑肌也有阳性反应，在正常肉鸡不出现阳性染色的肺小血管出现了强阳性染色的肺小血管出现了强阳性染色，肺小血管壁增厚，无肌性血管肌化，染色很深；亚临床腹水鸡有部分肺小血管内皮或平滑肌着色，研究结果表明正常肉鸡肺血管内皮有NOS活性，说明由NOS催化生成的NO对正常肉鸡肺血管张力有一定调节作用；腹水鸡肺水血管平滑肌层和内皮NOS表达增强，这可能与肺血管中膜增厚有关。     

实验性鸡大肠杆菌病病理学动态变化

用致病性大肠杆菌O18分离株和／或低致病性禽流感病毒（Mildly pathogenic avian influenza virus ,MPAIV)接种10－12日龄SPF鸡。在接种后1－96h进行临床症状与大体病理变化、组织学观察发现：大肠杆菌接种组、MPAIV接种组和健康接种组除扑杀鸡外未见鸡死亡，MPAIV与大肠杆菌混合接种组除扑杀鸡外死亡率为24％。混合接种组的病变比大肠杆菌接种组出现的时间早，恢复也慢，各脏器的病理变化更严重。MPAIV主要引起各实质器官的坏死，结果表明，大肠杆菌经气管内接种后试验鸡主要表现为呼吸道的炎症反应；MPAVI可使鸡大肠杆菌病严重化。     

粗粮型羊乳奶泡加工工艺的响应面优化

以羊乳、玉米面为主要原料,以产品的感官评分和硬度为响应值,利用响应面分析法对粗粮型羊乳奶泡的加工工艺进行优化。结果表明：最佳工艺参数为：玉米面与羊乳比例（m/V）0.435∶1、木糖醇与蔗糖比例（m/m）约0.712∶1、蔗糖酯（以质量分数计,下同）0.18%、β-环状糊精2.8%,柠檬酸0.0958%、明胶1.994%。研制出的产品不仅外观光滑、色泽均匀、口感清凉且甜度适中、兼有羊乳和玉米面的特有香味,感官分值达95.48分,硬度为371.95 g,适合于绝大部分人群,产品中的营养物质和保健成分也得以最大程度保留。     

桂林老虎猫瘟热病毒的分离鉴定

我们在作猫细小病毒分子流行病学调查过程中,从桂林送棼的考虑粪便中分离出１株虎细小病毒,并对其进行了系统鉴定,经形态学理化学血清学交叉中和试验、动物感染试验与分子生物学,证明为一株猫瘟热病毒（猫泛白细胞减少症病毒）的强毒。     

鹿血清蛋白抗氧化肽体外抗氧化性及其机理研究

在碱性蛋白酶最适条件下水解鹿血清蛋白,水解时间为0~5 h,鹿血清蛋白抗氧化肽的水解度(DH)随着水解时间增加而增加(P0.05),鹿血清蛋白抗氧化肽还原能力、清除自由基的作用和Cu2+螯合能力随着水解时间的增加而显著提高(P0.05),鹿血清蛋白抗氧化肽能有效抑制硫代巴比妥酸反应物质(TBARS)生成(P0.05)。结果表明,鹿血清蛋白抗氧化肽的抗氧化活性取决水解时间,鹿血清蛋白抗氧化肽是有效的抗氧化剂。     

紫花苜蓿品种根部特性与持久性和生物量的关系

植物的根部特性与其持久性和生产性能关系密切,但以往关于紫花苜蓿不同品种的相关研究报道较少。本试验通过对10个紫花苜蓿品种第10年的根部特性、生物量、持久性进行研究发现:不同品种紫花苜蓿根部特性差异显著(P＜0.05),其中,新疆大叶和公农1号根茎和主根粗壮,侧根数多;Super 7、Jindera、Eureka根茎和主根细小,侧根数少;L33、美国大叶、SD-006、甘农1号、Ranbule根部特性各指标居中。紫花苜蓿的根部形态指标与持久性和地上生物量显著相关,主根尤其是根茎越健壮侧根数越多,持久性越好;主根和根茎越粗壮,地上生物量越高。综合评价认为,新疆大叶和公农1号根部各形态指标均优于其他品种,地上生物量和持久性好,可以选择为适宜的紫花苜蓿品种在甘肃河西地区推广种植。     

紫茎泽兰潜在分布对气候变化响应的研究

紫茎泽兰的生态适应性强,是我国外来入侵物种中危害最为严重的恶性杂草。研究紫茎泽兰的适生性特征及对全球气候变化的响应规律是制定防控策略的重要基础,为此,本研究采用了将生态位因子分析(ENFA)与最大熵模型(MaxEnt)嵌套的方法,首先通过ENFA对环境因子进行降维,利用降维后的环境因子以及当前及A1b情景的未来气候数据,根据最大熵模型(MaxEnt)预测紫茎泽兰的潜在分布,并使用ROC曲线分析对预测结果进行评价。结果显示,当前气候情景下,紫茎泽兰的分布区以云南、贵州、广西等省为主;未来A1b情景下,易入侵等级(入侵概率为0.6~1.0)的区域面积将会由当前的12.82 km²增加至2080s的21.30 km²,中心点将由当前位置向西南方向移动61 km;而其中高入侵概率等级(入侵概率为0.8~1.0)的区域面积将由当前的0.42 km²增加至2080s的0.91 km², 中心点将由当前位置向东南方向移动178.66 km。根据当前及未来A1b气候情景下紫茎泽兰潜在分布情况,并根据不同入侵等级区域采取相应的防除治理措施,将对紫茎泽兰的综合治理具有重要指导意义。     

Isolation and Identification of Erysipelothrix rhusiopathiae from Abattoirs in Shanghai Area

In order to comprehend the status of Erysipelothrix rhusiopathiae carried in swinery in Shanghai area, samples of pigs were collected from some standard abattoirs in Shanghai area, including nasal swab, lung, tonsil and mandibular lymph nodes. Strains were isolated from these samples for detecting the Erysipelothrix rhusiopathiae. Several kinds of methods were used, such as VITEK 2 Compact system and VITEK MS system. A pair of primers was designed to amplify the 16S rRNA gene. 16 PCR products selected randomly were sequenced and 16S rRNA homology analysis was conducted. As a result, strains were isolated from 49.07% (105/214) samples and were identified as Erysipelothrix rhusiopathiae.16S rRNA homology in strains of isolation and reference were 99.6% to 100.0%. The result indicated that the situation was very severe for so many carriers of Erysipelothrix rhusiopathiae in health group in nursery.     

Detection of Serotypes and Virulence Factors of Escherichia coli from Piglets in Beijing

To investigate the cause of piglets diarrhea, and the distribution of the serotype and virulence factors of swine Escherichia coli in Beijing, 400 diarrhea samples were collected. TSA serum agar culture method was used to isolate Escherichia coli, serotype identification test and virulence factor genes test were used to verify the presence of O-antigen. 64 strains of E.coli were isolated from 400 diarrhea samples, among which 42 strains of E.coli were classified as 8 serotypes:O101(18.7%),O64(12.5%),O8(10.9%),O20(10.9%),O45(4.7%),O149(4.7%),O2(1.6%) and O89(1.6%), and the major virulence factors were STa, Stx2e, astA and eaeA. There were 8 mainly serotypes that caused piglets diarrhea in Beijing area, among which O101 serotype accounted for the highest proportion. The major virulence factors were astA and eaeA, accounted for more than 50% of all strains, STa and Stx2e accounted for more than 30% of all strains. These data would provide effective data to support the prevention and control of piglet diarrhea in Beijing.     

Isolation and Identification of Variant HeNZK-2014 of Pseudorabies Virus and Sequence Analysis of gE Gene

In order to learn the situation of pig pseudorabies virus (PRV) variant in this study, tissue samples such as lymph nodes which were collected from clinical pigs with suspected PRV infection were identified by PCR. PRV positive sample were inoculated on PK-15 cells after grinding and degerming, with further experiment including virus isolation, plague purification, PCR and IFA identification, TCID₅₀ confirmed by Reed-Muench method, inoculation test and observation of clinical symptoms in mice. The gE gene of purified PRV and brain tissue samples of dead mice were identified by sequencing analysis. The results showed that the virus grown on PK-15 cells could produce typical cytopathic effect (CPE) after 24 h; After three rounds of plaque purification,the isolate was PRV positive identified by PCR and IFA, and nominated as HeNZK-2014; The TCID₅₀ of the isolate was 10^-9.77/0.1 mL; The virus in 1×10⁸ TCID₅₀ inoculation was able to cause itching, tearing, death in infected mice, and PRV could be detected in tissues of dead mice; The molecular genetic variation analysis of gE gene by PCR amplification and clone sequencing indicated that the gE gene from brain tissue of infected mice shared 100.0% homology with HeNZK-2014, and located in a relatively independent branch with newly pandemic isolates in recent years after 2011, but was far from the classical strains before 2011, and both had two insertion of aspartic acid (D) at sites of 48 and 496 amino acids, which were considered to be the typical characteristics of PRV variants. This study successfully isolated a PRV variant, which laid a foundation for further research on vaccine development, prevention and control against PRV variants.