氧化钕经鼻滴注对小鼠神经系统的影响

研究氧化钕经鼻滴注对小鼠神经系统的影响,进一步考察氧化钕的神经毒性是否存在剂量和尺寸效应。选取健康的ICR雌鼠48只,随机分为对照组、低剂量纳米(L-nm)氧化钕组(1μg/mL)、高剂量纳米(H-nm)氧化钕组(40μg/mL)和低剂量微米(L-μm)氧化钕组(1μg/mL)。经鼻染毒,共10d,隔天1次;染毒第2次之后进行水迷宫试验,定位航行试验7d,1d一个单元,同时在第7天进行空间探索试验;取血,进行生化指标检测;取脑置于100g/L甲醛溶液固定,常规脱水,石蜡包埋、切片,苏木素-伊红(HE)染色。剂量效应显示,不同浓度纳米氧化钕对小鼠经鼻滴注,高纳米组与低纳米组相比,目标象限游程占总游程百分比较高(P0.05),但在此尺寸条件下剂量效应不明显。尺寸效应显示,相同浓度纳米氧化钕对小鼠经鼻滴注,L-μm组海马颗粒细胞排列稀疏,细胞脱落;L-nm组海马齿状回颗粒细胞排列较整齐,可见部分细胞核固缩在此试验浓度条件下尺寸效应不明显。血液生物标志物检查试验显示,氧化钕经鼻滴注会对小鼠肝功能、肾功能产生一定的损伤。不同浓度纳米氧化钕经鼻滴注,对小鼠有轻微的刺激学习记忆的作用,但剂量效应不明显。低微米氧化钕对小鼠神经系统有轻微的损伤,但与低纳米氧化钕相比,差异不显著,表明尺寸效应不明显。     

不同温度条件下红颈常室茧蜂蛹和成虫过冷却点和结冰点的测定

通过比较不同温度下红颈常室茧蜂Peristenus spretus Chen et van Achterberg蛹、雌蜂、雄蜂以及不同日龄的滞育蛹的过冷却点和结冰点,以明确红颈常室茧蜂蛹、成虫和滞育蛹耐寒能力的差异。结果表明:蛹的过冷却点和结冰点均显著低于成虫、滞育蛹的过冷却点和结冰点均显著低于非滞育蛹;相同温度下,雄蜂和雌蜂之间的过冷却点、结冰点差异不显著;滞育蛹的过冷却点和结冰点随着滞育时间延长而逐渐降低,在滞育150d时,其过冷却点和结冰点最低,分别为(-23.36±0.60)℃与(-22.92±0.65)℃。该研究结果有助于推测此蜂在我国的越冬分布区,并对其大规模繁殖和滞育蛹的保存具有重要的实用价值。     

温度响应型吡唑醚菌酯微囊的制备与性能表征

以N-异丙基丙烯酰胺（NIPAM）和丙烯酸丁酯（BA）的共聚物为壁材,采用乳液聚合法制备了温度响应型吡唑醚菌酯微囊。通过光学显微镜、扫描电镜、激光粒度分析仪和紫外分光光度计等对该微囊的形貌、粒径、包封率和载药量进行表征,同时采用透析袋法探讨其释放性能,并以斑马鱼为试材测定其对水生生物的急性毒性。结果表明:吡唑醚菌酯微囊呈球形,平均粒径为1.04 μm,包封率为78.30%,载药量为15.66%。吡唑醚菌酯微囊具有明显的温度响应性特征,其低临界溶解温度（LCST）为28.2℃,当环境温度高于28.2℃时能够快速释放活性成分,而低于该温度时其释放行为受到抑制。吡唑醚菌酯微囊对斑马鱼急性毒性的LC50（96 h）值为有效成分4.48 mg/L,较吡唑醚菌酯原药的提高了90倍以上,因此能够显著提高吡唑醚菌酯对水生生物的安全性。     

青刺果酵母发酵液活性成分分析及其抗氧化活性研究

采用水提取和微生物提取的方式对青刺果(Prinsepia utilis Royle)黄酮、总糖进行提取,并测定粗提液对DPPH自由基的清除作用。结果表明,水提取与微生物提取青刺果黄酮的提取率分别为0.37%和0.88%,水提取与微生物提取青刺果总糖提取率分别是7.65%和3.38%。青刺果微生物提取液对DPPH自由基的清除作用在相同的稀释倍数下高于水提取液,表明微生物提取植物中活性物质具有一定可行性和优越性。     

微生物发酵法制备铁皮石斛多糖及抗氧化活性的研究

采用微生物发酵法提取铁皮石斛中的多糖,探讨料液比和pH对多糖提取率的影响,并评价多糖的体外抗氧化活性。2因素3水平正交法优化的铁皮石斛多糖提取,料液比为1∶90(g/mL),pH为5,在此条件下的多糖提取率为42.86%;探究微生物发酵铁皮石斛多糖对羟自由基和DPPH自由基的清除作用,结果显示,微生物发酵法制备的铁皮石斛粗多糖具有一定的抗氧化性,且自由基清除率在一定范围内随浓度增加而增强。     

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.     

阿司匹林丁香酚酯对大鼠的急性毒性研究

试验旨在评价阿司匹林丁香酚酯（aspirin eugenol ester,AEE）对大鼠的急性毒性,了解AEE毒性特点及可能的毒性靶器官,并全面地分析大鼠的致死原因。试验按照改良寇氏法进行,预试验选取50只大鼠,雌雄各半,分为5组,测定绝对致死量（LD₁₀₀）和最大非致死量（LD₀）。根据预试验结果,将80只健康大鼠,雌雄各半,随机平均分为7个药物组（剂量分别为2.62、3.25、4.03、5.00、6.20、7.69和9.53 g/kg）和1个对照组（给予0.5%的羧甲基纤维素钠（CMC-Na）进行正式试验。灌胃给药,观察并记录大鼠给药后的临床症状及体重变化。给药14 d后,统计各剂量组大鼠的死亡时间及总死亡数,并计算AEE的半数致死量（LD₅₀）及其95%可信限。同时对死亡大鼠及时进行剖检,将具有病变的组织用10%的甲醛溶液固定,以进行病理学分析。结果显示,AEE对大鼠口服的LD₅₀是5.95 g/kg,且LD₅₀的95%可信限为5.30~6.68 g/kg。对大鼠的死亡时间进行分析可得出,当口服AEE的剂量大于4.03 g/kg时,其死亡时间主要集中在染毒后的48~96 h内。大鼠染毒后3 d内,体重呈下降趋势,常规饲养第5天开始,大鼠体重可逐渐恢复。病理学检查分析发现,AEE的剂量在5.00 g/kg以上时,对大鼠的肝脏、肾脏和胃肠道有明显损伤。根据外源化学物急性毒性分级（WHO）可知,AEE为实际无毒化合物,AEE对大鼠毒性靶器官主要是肝脏、肾脏和胃肠道。     

Dispersal of invasive Phytolacca americana seeds by birds in an urban garden in China

Although seed dispersal is a key process determining the regeneration and spread of invasive plant populations, few studies have explicitly addressed the link between dispersal vector behavior and seedling recruitment to gain insight into the invasion process within an urban garden context. We evaluated the role of bird vectors in the dispersal of pokeweed (Phytolacca americana), a North American herb that is invasive in urban gardens in China. Fruiting P. americana attracted both generalist and specialist bird species that fed on and dispersed its seeds. The generalist species Pycnonotus sinensis and Urocissa erythrorhyncha were the most frequent dispersers. Seedling numbers of P. americana were strongly associated with the perching behavior of frugivorous birds. If newly recruited bird species use seedling‐safe perching sites, the P. americana will regenerate faster, which would enhance its invasive potential. Based on our observations, we conclude that the 2 main bird vectors, P. sinensis and U. erythrorhyncha, provide potential effective dispersal agents for P. americana. Our results highlight the role of native birds in seed dispersal of invasive plants in urban gardens.     

日粮中添加乡土草可改善獭兔生产性能及血液指标

为研究乡土草日粮对商品獭兔后期生产性能、毛密度及血液生化指标的影响,本研究选用健康无病、精神状态良好的110日龄试验兔30只,公母各半,按性别随机分为3组,每组10只。试验Ⅰ组为对照组,饲喂基础日粮;试验Ⅱ组饲喂15%当地乡土草草粉+85%基础日粮;试验Ⅲ组饲喂30%当地乡土草草粉+70%基础日粮。预试期7d,正试期30d。结果表明,试验组提高了獭兔末重、平均日增重、平均日采食量以及体况评分,降低了料重比;与对照组相比,试验Ⅲ组末重、平均日增重、平均日采食量及体况评分分别提高了9.78%、57.9%、4.02%及7.38%(P0.05),而料重比降低了9.4%(P0.05)。试验组提高了獭兔各部位被毛密度,试验Ⅲ组效果最好,与对照组相比,獭兔背部、腰部、左肩部和右肩部毛密度分别提高了20.7%、38.6%、33.7%和47.3%(P0.05),而臀部毛密度提高了12.9%(P0.05)。试验组提高了獭兔总蛋白、白蛋白、球蛋白、白球比、免疫球蛋白G含量,与对照组相比,试验Ⅲ组总蛋白提高了15%,白蛋白提高了13%(P0.05);球蛋白提高8.6%,白球比提高了23.5%,免疫球蛋白G提高了30%(P0.05)。综上所述,30%乡土草草粉替代基础日粮提高了獭兔生产性能。     

基于全卷积网络的哺乳母猪图像分割

猪舍场景下,光照变化、母猪体表颜色不均及与环境颜色对比度不大、母猪与仔猪的粘连等,均给目标分割带来很大的困难。该文提出了基于全卷积网络(FCN,fully convolutional networks)的哺乳母猪图像分割算法。以VGG16为基础网络,采用融合深层抽象特征与浅层细节特征并将融合的特征图上采样8倍的跳跃式结构,设计哺乳母猪分割的FCN。利用Caffe深度学习框架,以7栏伴有不同日龄仔猪的3811幅哺乳母猪训练样本进行母猪分割FCN训练,在另外21栏的523幅哺乳母猪测试集上的分割结果表明:该算法可有效避免光线变化、母猪颜色不均、小猪遮挡与粘连等影响,实现完整的哺乳母猪区域分割;分割的平均准确率达到99.28%,平均区域重合度达到95.16%,平均速度达到0.22 s/幅。与深度卷积网络的SDS(simultaneous detection and segmentation)及传统的基于图论的图像分割、基于水平集的图像分割方法做了对比试验,该文分割方法平均区域重合度分别比这3种方法高出9.99、31.96和26.44个百分点,有较好的泛化性和鲁棒性,实现了猪舍场景下哺乳母猪准确、快速分割,可为猪只图像分割提供了技术参考。