微波消解-石墨炉原子吸收光谱法测定醋酸地塞米松中的微量硒

采用微波制样技术对样品进行消解,减少了消化过程中硒的损失,利用石墨炉原子吸收光谱法对醋酸地塞米松中微量硒进行测定.以4 mg/mL Pd(NO3)2作为基体改进剂,灰化温度为950 ℃,原子化温度为2 100 ℃时,经氘灯校正背景,测定硒含量,回收率在89.24%～112.37% 之间,方法的相对标准偏差为7.42%,检出限为0.53 ng/mL.该法具有简便、快速、灵敏、稳定、准确等优点,适用于醋酸地塞米松中微量硒的分析测定.     

金丝桃素提取、分离方法的研究

目的:研究贯叶连翘中有效成分金丝桃素提取方法。方法:应用有机溶剂溶解法、薄层色谱法、紫外检测、高效液相色谱(HPLC)等方法探讨贯叶连翘中金丝桃素提取方法。结果:用石油醚除叶绿素、花青素,以丙酮为溶剂在60℃水浴中提取贯叶连翘中金丝桃素和酮类衍生物,在真空度为0.07MPa、温度为60℃水浴条件下浓缩。后用100-200目硅胶分离金丝桃素,钢瓶冻干,得含金丝桃素为1.08%深红色产品。     

猪水疱病自杀性DNA疫苗的初步研究

利用RT—PCR技术，用保真酶扩增获得猪水疱病病毒外壳蛋白1BCD基因，克隆于DNA复制子载体pSCAl中，获得重组质粒pSCA／1BCD。将重组质粒转染BHK-21细胞，RT-PCR法和间接免疫荧光法检测显示，猪水疱病病毒外壳蛋白基因在转染细胞中表达。豚鼠免疫试验表明，自杀性DNA疫苗pSCA／1BCD可诱导SVDV特异性抗体和T淋巴细胞增殖。     

嗜水气单胞菌弹性蛋白酶的纯化及特性分析

为阐明嗜水气单胞菌弹性蛋白酶的性质及其在致病过程中的作用，试验以我国分离的嗜水气单胞菌J-1株为研究对象．纯化了其弹性蛋白酶．并对该酶进行热稳定性、蛋白酶抑制剂抑制作用、金属离子影响和致病性等特性分析。结果表明．嗜水气单胞菌J-1株的培养上清经35％～60％硫酸铵沉淀、阴离子交换层析和凝胶过滤层析，可获得纯化的弹性蛋白酶．SDS-PAGE显示单条带．相对分子质量约38000。该酶对热稳定，EDTA可抑制其活性，PMSF对其无影响，金属离子铜、锌、钴等抑制其活性。说明此酶属于热稳定金属蛋白酶。腹腔注射纯化的弹性蛋白酶能致死小鼠．其对小鼠的LD50为6．4μg（0．2mL）．表明该酶是一种直接致病因子。     

实验室间比对试验结果的评价——Robust法

概述了Robust评价法的特点，总结了该法的评价步骤，并通过举例进一步介绍了该法在评价实验室间比对试验结果的具体应用。     

骡几种舌色与血液流变学指标相关性

用血液流变学方法测定了27匹健康成年骡和188例病骡的全血黏度、还原全血黏度以及血细胞压积、红细胞电泳时间。结果显示：随着舌色由淡红、红、赤红、暗红的转变，7种切变率下的全血黏度、还原全血黏度以及血细胞压积、红细胞电泳时间逐渐增加。其中全血黏度、还原全血黏度、血细胞压积差异显著或极显著（P〈0．05或P〈0．01）。淡红、红、赤红、暗红四种舌色的全血黏度和还原全血黏度均随着切变率的增加而逐渐降低。这一结果说明，血液流变学主要指标与家畜舌色之间存在密切关系。     

金丝桃素对口蹄疫病毒的体外抗病毒实验

本文报道了金丝桃素体外抗口蹄疫病毒（FMDV）的研究结果。采用双抗体捕获抗原法、病毒滴度测定、MTT法、组织细胞培养等方法均检测到抗病毒作用。结果显示：金丝桃素在BHK-21细胞感染FMDV前、后及同时加入，都有明显抑制细胞病变的作用。金丝桃素使FMDV的TCID50从8．5下降到6．25。双抗体捕获抗原法检测到金丝桃素有效抑制FMDVBHK-21细胞的吸附、融合，抑制率可达59．72％。研究结果提示：金丝桃素在体外有抗口蹄疫病毒作用，抑制口蹄疫病毒与宿主细胞的吸附、融合是抗病毒的重要途径之一。     

车用后栏板举升机构的计算机辅助动力学分析

对车用后栏板举升机构进行了运动学和动力学分析。利用MATLAB编制了相应的程序,并以实例进行了分析和计算,对分析此类机构的稳定性和优化设计具有一定的参考价值。     

褪黑激素ELISA方法的建立

将褪黑激素（MLT）与牛血清白蛋白（BSA）连结的复合物（MLT：BSA＝12：1）免疫5只雄性新西兰大耳兔，收集高效价血清，并提纯抗体。在96孔微量反应板上，以1：10000的抗体包被，将MLT与酶标MLT先后加入到板中竞争结合抗体，制定标准曲线，建立了MLT酶联免疫测定法（MLT－ELISA）。此方法灵敏度为17．31pg,板内变异系数8．1％，板间变异系数15．4％，用建立的此法测定夏至时考力代羊昼夜血样，测定结果跟国外报道的基本一致；用放射免疫法检测同一批血样，也获得类似结果，从而表明此方法可信。     

Study on the Cecal Microbial Community Structure and Diversity of Tibetan Pigs in Tibetan Plateau

The purpose of this study was to investigate the cecal microbial community composition and diversity of grazing Tibetan pigs, captive Tibetan pigs and lean type pigs (DLY pigs) in Tibetan plateau, in order to partially revealed the specificity of the intestinal microbial community of Tibetan pigs. Pigs with the same age were chosen, including 5 grazing Tibetan pigs, 5 captive Tibetan pigs and 5 DLY pigs. The grazing Tibetan pigs were free range husbandry by local herdsman. The captive Tibetan pigs and DLY pigs were reared in pens and fed with same diets. At the age of 160 days, all the pigs were slaughtered by anterior vena cava bloodletting. Cecal chyme was collected and rapidly frozen with liquid nitrogen. The V3-V4 regions of the 16S rRNA genes were amplified and sequenced using high-throughput sequencing techniques. The results showed that a total of 659 904 valid sequences were obtained from the V3-V4 region of 16S rRNA in 15 samples, including grazing Tibetan pigs 213 031, captive Tibetan pigs 219 417 and DLY pigs 227 456. Interestingly, the cecal OTUs quatity, Chao1 index, ACE index and Shannon index of the grazing Tibetan pigs were significantly higher than those of the other pigs (P<0.05), but there was no significant difference between the captive Tibetan pigs and DLY pigs (P>0.05). The microbiota of 3 types of pigs were divided into 13 phyla and 56 genera, and Firmicutes has the highest relative abundance in all pigs. The relative abundance of Actinobacteria and Verrucomicrobia were significantly higher in grazing Tibetan pigs than those of the others (P<0.05), but Bacteroidetes was remarkably higher in captive Tibetan pigs (P<0.05). The relative abundance of 11 genera in grazing Tibetan pigs was significantly higher than captive Tibetan pigs and DLY pigs (P<0.05). These results indicated that the cecal microbial community structure and diversity of grazing Tibetan pigs were unique, which could provide reference for further developing the Tibetan pig resources.