液相色谱-串联质谱法测定禽粪便中尼卡巴嗪的残留量

本试验建立了一种测定禽粪便中尼卡巴嗪(以DNC计)的残留量的超高效液相色谱串联质谱(UPLC-MS/MS)检测方法.以甲醇:0.2％甲酸水溶液(75+25)为流动相,0.2 mL/min流速,30℃柱温下,超高效液相色谱分离,三重串联四级杆质谱多反应监测(MRM)扫描模式检测,DNC-D8同位素内标法进行定量.试验结果表明,DNC浓度在10～1000 ng/mL时,呈良好的线性关系,R2为0.9996;4组不同浓度各6个平行样的回收实验,回收率范围为84.8％ ～ 91.2％,平均回收率达到87.9％;相对标准偏差RSD范围为2.47％ ～ 5.45％.本方法特异性强、定性准确、灵敏度高,完全能满足禽粪便中尼卡巴嗪的残留检测.     

IBV AH1-99分离株N基因的克隆及序列分析

利用RT-PCR技术成功扩增出IBV AH1-99分离株的N基因全长cNDA,将其克隆到pMD18-T载体上。经酶切分析、PCR鉴定及核苷酸序列测定,成功获得该分离株N基因的重组质粒。序列分析结果表明,分离株N基因全长1 230个核苷酸,编码409个氨基酸。同部分IBV参考毒株相比,核苷酸同源性为85.8%~89.9%,氨基酸同源性为86.6%~91.0%,在进化关系树中,AH1-99与国内分离株X、LX4亲缘关系较近。     

Clenbuterol诱导载酯蛋白D在猪脂肪组织中表达加强

Clenbuterol(CLB,盐酸克伦特罗),俗称瘦肉精。由于其在动物体内广泛残留,可能导致食用此类产品的人中毒而被禁止使用,但已有研究表明该制剂可显著减少猪脂肪沉积,因此,对其分子机制进行深入研究将具有重要的理论与实践价值。本研究通过对家猪饲喂高剂量clenbuterol(≥1.5mg/kg体重),提高瘦肉率10%左右。通过实时荧光定量PCR技术对脂肪组织中与脂类代谢密切相关的4个基因研究发现,饲喂clenbuterol的猪脂肪组织内载酯蛋白D(apolipoprotein D,apoD)mRNA丰度增加超过2倍,而脂蛋白酯酶(lipoprotein lipase,lpl)、硬酯酰辅酶A去饱和酶(stearoyl-CoA desaturase,scd)和激素敏感脂酶(hormone sensitive lipase,hsl)mRNA丰度变化不明显。因此,推断clenbuterol通过改变部分脂代谢关键基因的表达来实现减少脂肪积累。载酯蛋白D可能是CLB应答基因之一。     

大叶桉叶挥发油的抗炎活性研究

大叶桉叶为双子叶植物桃金娘科大叶桉（Eucalyptus robusta Smith）之叶,味辛、苦,性凉,具有疏风发表、清热解毒、祛痰止咳、杀虫止痒之功效。大叶桉是华南地区民间常用中草药,其叶水煎剂具清热解毒、消炎止痛、防腐止痒的功效,其总挥发油可用于治疗流行性感冒、上呼吸道感染和皮肤病等疾病。     

猪场常见繁殖系统疾病的临床区别诊断

布氏杆菌病、细小病毒感染、猪繁殖与呼吸障碍综合征(PRRS)、猪瘟、猪伪狂犬病、猪乙型脑炎、猪附红细胞体病、衣原体、猪钩端螺旋体及饲料霉菌毒素中毒都共同出现流产症状,同时也有很多不同点。本文根据临床经验,将其归纳整理,系统地比较各病之间的不同点,为临床兽医正确区别诊断这类疾病提供宝贵的经验。     

Ecotourist trail-use affects the taxonomic,functional and phylogenetic diversity of mammals in a protected area: lessons for conservation management

Ecotourism, by definition, aims to engage peoples’ interest in wildlife and the environment. The use of tourist roads and trails to access sites within protected areas (PAs) can detrimentally affect the behavior and distribution of species. The way mammals respond to anthropogenic pressures may differ across taxonomic, functional, and phylogenetic groups; nevertheless, how ecotourist trail-use affects these different diversity remains under-investigated. Here, we assessed 6 metrics of taxonomic, phylogenetic, and functional diversity for a mammal community in a PA in central China, recording how Trail use (using Trail type as a proxy) and habitat variables affected sightings and signs of mammals across 60 replicate 0.5 km transects. We then examined how Trail use affected the taxonomic, functional, and phylogenetic diversity indices of species (>1 kg). Using generalized liner mixed modeling, we identified that more used trail types had a greater adverse effect on all diversity richness indices than did less used trail types. Consequently, tourist pressure was associated with a general tendency to homogenize the site's mammal community. In contrast, the effects of Trail Types on all diversity evenness indices were non-significant. Furthermore, more developed and more heavily used trail types had a greater, significant negative effect on taxonomic, functional, and phylogenetic richness, whereas these richness indices were unaffected by minor trail types, used less intensively. As a general principle, lower biodiversity indices reduce ecosystem resilience, and so it is vital to better understand these responses to balance public access against biodiversity management in PAs.     

甘肃省草原产草量动态监测模型

利用MODIS数据和地面实测资料,研究了甘肃省不同草原区的最适草原生物量遥感估算模型,并反演了甘肃省2005-2009年的草原产草量,分析了其空间分布特征。结果表明,不同草原区适合的植被指数和反演模型类型存异,其中河西走廊高平原荒漠草原区适合的植被指数是RVI、模型类型为对数模型,甘南高原草甸草原区适合的植被指数是EVI、模型类型为指数模型,而黄土高原温性草原区适合的植被指数是NDVI、模型类型为二次多项式模型。甘肃省2009年草原总产鲜草3 718.30万t,整体呈现东北低、西南高的空间变化过程,形成3个高产中心,分别是甘南高原、祁连山北麓中东段和陇南南部。与1985年相比,2005年草原明显减产(相对变化率V=19.34%),但2005-2009年间甘肃省草原产草量有总体上升的趋势。     

Micro-computed tomography evaluation and pathological analyses of female rats with collagen-induced arthritis

Imaging techniques have been introduced to assess the efficacy and toxicity of developing pharmaceuticals. The purpose of this study was to perform a comprehensive characterization of collagen-induced arthritis (CIA) in rats using micro-computed tomography (micro-CT) and to compare the results with data from conventional pathological examination. Arthritis was induced by collagen in 24 female Wistar rats. Micro-CT and pathological analyses were performed to assess arthritis progression. Micro-CT analysis showed marked joint destruction occurring in a time-dependent manner following collagen administration. Bone volume was significantly decreased in the tibia at weeks 3 and 4 compared to week 0 (p < 0.05 and p < 0.01, respectively). Additionally, percent bone volume was significantly reduced in the tibia at week 4 compared to week 0 (p < 0.05). In contrast, bone surface/bone volume and trabecular separation were significantly increased in the tibia of the animals at week 4 compared to week 0 (p < 0.05). Severe joint destruction with extensive inflammation, erosion of cartilage and bone, and infiltration of inflammatory cells were observed in the knee joints of the collagen-treated rats. Taken together, micro-CT made it possible to quantify CIA lesions and should be performed with pathological examination in rats.     

富硒女贞子粗多糖对小鼠免疫功能的影响

从富硒女贞子及女贞子中提取粗多糖,探讨其对小鼠免疫功能的影响。将90只小鼠随机均分为3组:对照组、富硒女贞子粗多糖组、普通女贞子粗多糖组。对照组灌服生理盐水,试验组小鼠灌服粗多糖液,灌服2次,每次连续5 d。2次灌胃的第3天注射卵清蛋白,二免后测定胸腺脾脏指数;MTT法检测脾淋巴细胞增殖水平;ELISA试剂盒检测血清中IL-2、IL-4、IFN-γ生成水平及相应抗体生成水平。结果显示:与对照组相比,试验组脾脏和胸腺指数明显升高,脾淋巴细胞增殖作用显著提高;IL-2、IL-4、IFN-γ生成水平明显提高,其中IFN-γ与对照组存在显著差异;而对特异性卵清抗体生成影响不大。这表明富硒女贞子粗多糖较普通女贞子粗多糖能更好地促进机体非特异性免疫及细胞免疫,从而增强机体免疫功能,在特异性体液免疫的作用方面则没有表现出明显的规律性,还需进一步研究。     

桑树多倍体育种材料遗传背景的AFLP分析

利用AFLP(Amplified Fragment Length Polymorphism)分子标记技术,即扩增片段长度多态性,从DNA分子水平对19份人工三倍体桑育种材料进行了遗传背景分析,构建了指纹图谱.19份育种材料可组配70个杂交组合,各材料间AFLP相似系数大于0.750 0的有54个组合,经AFLP分析认为,它们不宜作亲本间杂交组合;AFLP相似系数小于0.750 0的有16个组合,经AFLP分析认为它们适于作亲本间杂交组合.本研究从基因组DNA分子水平上为人工三倍体桑品种选育以及杂交亲本的选择和组配提供了遗传背景依据.