不同仓型的粮堆温度场重现及对比分析

为了揭示不同仓型粮堆内温度场和水气分压场随季节的变化规律及其对储粮安全的影响,该文以天津地区的钢板浅圆仓和平房仓为研究对象,以小麦为储粮目标,采用阵列式分布的温度传感器监测粮堆温度,利用温度拟合算法和WU模型构建粮堆温度场模型,重现粮堆在冬末春初之际和夏季的温度场和水气分压场分布;根据温湿度场耦合理论分析其云图特征,并在此基础上比较2种仓储粮状态的差异。结果表明:夏季,浅圆仓和平房仓的小麦粮堆中均存在大体积的冷芯,使整个粮堆可以安全度夏;冬春交替之际,2种仓的粮堆中均存在多区域分层现象,但由于浅圆仓的表层粮堆水分吸收速率大于平房仓,致使次年春季浅圆仓的粮堆表层更易发生结露;根据平房仓小麦粮堆的等温曲线变化方向可推测有邻仓存在,且由2个毗邻的平房仓温度场融汇度可判定邻仓有储粮。研究结果将为粮堆结露研究提供新思路,为结露预测提供理论依据。     

鱼类神经坏死病毒纳米探针的制备与特征分析

为了快速检测鱼类神经坏死病毒,本研究设计了病毒特异性的发夹型探针,经硫醇修饰后与纳米银溶胶结合,制备了鱼类神经坏死病毒纳米探针（Ag-NNV）,并使用透射电镜、多功能酶标仪、表面增强拉曼光谱仪等对纳米探针Ag-NNV的表征及发夹型探针在纳米银粒子表面的覆盖率进行了测定和分析。结果表明,裸露的纳米银粒子为球形,平均直径50 nm;制备的纳米探针颗粒为球形,平均直径90 nm。纳米银粒子和纳米探针在溶液中均具有良好的分散性。平均每个纳米银粒子表面结合发夹型探针约100条,单位表面积的探针覆盖量为0.56 pmol/cm2。该纳米探针制备简便,适合用于表面增强拉曼散射法对鱼类神经坏死病毒进行快速检测。     

Lymphocyte proliferation in lymphoid organs of the dromedary camel using the monoclonal antibody MIB-5 against the proliferation-associated nuclear epitope Ki-67

Detection of proliferating lymphocytes is useful for studying immune reactions and for the prognosis of tumours of lymphocyte origin. Markers detecting proliferating cells are lacking in the dromedary camel. This study deals with the immunohistochemical detection of the Ki-67 proliferation-associated nuclear epitope using MIB-5 in frozen sections from spleens, different lymph nodes and haemal nodes of eight camels (0.5-12 years old). Frozen sections from rat spleens were labelled in parallel with camel tissue as a positive control. Large numbers of cells expressing the Ki-67 epitope were localized in germinal centres of all lymphoid organs tested. A few cells were found in the periarterial lymphoid sheath and the red pulp of the spleen, also in the lymphatic cords of the lymph nodes and the haemal nodes. There were no obvious differences in respect to the age of the animals. The Ki-67 epitope is well expressed by proliferating cells in camel lymphoid organs. MIB-5 can be applied to identify this epitope and will be a useful marker for cell production in immune reactions.     

四川部分地区奶牛源无乳链球菌的分离鉴定、毒力基因检测及耐药性分析

为了解四川部分地区奶牛源无乳链球菌的毒力因子、感染及耐药情况,对2017-2019年采集的313份临床型奶牛乳房炎乳样进行病原菌分离培养,采用K-B纸片扩散法和PCR法对分离的无乳链球菌进行药敏试验、荚膜分型、毒力基因和耐药基因检测。结果表明,313份乳样共分离到105株无乳链球菌,分离率为33.55%,分离菌株的荚膜全部为Ia型。药敏结果显示,分离菌株对氨基糖苷类药物敏感,对β-内酰胺类药物耐药,耐药基因检测结果也与表型一致。毒力基因检测结果显示,除bac和lmb基因未检测到,cfb、cylE、fbsA、fbsB、hylB和α-enolase基因检出率为100%。结果表明,四川不同地区分离的无乳链球菌荚膜分型一致,并且具有相似的药物敏感性和毒力因子。     

Histology and Ultrastructure of the Lymph Nodes of the Buffalo (Bos bubalus)

Pre‐scapular, femoral and mesenteric lymph nodes from five buffalo calves and five buffalo bulls were studied using light and transmission electron microscopy. The nodes were surrounded with a thin capsule of dense connective tissue and smooth muscles. Subcapsular and trabecular lymphatic sinuses were lined with endothelial cells resting on a basement membrane. The cortex was formed by lymphoid follicles and inter‐follicular lymphocytes. Primary and secondary follicles were observed. The medulla was made up of medullary cords of lymphocytes separated by lymphatic sinuses. These sinuses were lined with a discontinuous epithelium and interestingly crossed by reticular fibres. High endothelial venules were found in the paracortical area. Several lymphocytes were observed infiltrating the wall of these venules. The lymph nodes of the Egyptian water buffalo showed a typical structure compared with the majority of mammals, with no age‐related structural variation.     

Identity and public health potential of Cryptosporidium spp. in water buffalo calves in Egypt

Little is known about the diversity and public health significance of Cryptosporidium species in water buffaloes. In this study, we examined the distribution of Cryptosporidium spp. in water buffalo calves in Egypt. Rectal fecal specimens from 179 calves and 359 adults were screened microscopically for Cryptosporidium oocysts using modified Ziehl–Neelsen stain. Cryptosporidium spp. in 17 microscopy-positive specimens from calves were genotyped by DNA sequence analysis of the small-subunit rRNA gene, and Cryptosporidium parvum was subtyped by sequence analysis of the 60 kDa glycoprotein gene. Cryptosporidium ryanae was found in 10 specimens and C. parvum in 7 specimens, with the former belonging to the newly identified C. ryanae buffalo variant and the latter belonging to the subtypes IIdA20G1 (in 5 specimens) and IIaA15G1R1 (in 2 specimens). The prevailing occurrence of C. ryanae and the subtype family IId of C. parvum and the absence of C. bovis and C. andersoni represent some features of Cryptosporidium transmission in water buffaloes in Egypt.     

基于粮温统计特征的粮仓库存状态检测方法

粮仓历史库存状态的准确检测可以为清仓查库工作提供线索,该文通过分析粮温统计特征,提出了一种基于历史粮温统计特征的粮仓库存状态(主要包括空仓、新粮、通风3种状态)检测方法。利用粮堆上下相邻层温差和粮温的新异众比例检测空仓态,利用相邻层温差和粮温标准差检测新粮态,利用层温变化率和粮温标准差变化率检测通风态。提出了一种类多变量决策树的粮仓库存状态检测方法;通过分析11个粮仓历史粮温的统计特征,确定了决策树节点特征参数的最优阈值。最后选择7个不同省份的粮仓,利用提出的检测方法进行库存状态检测试验,试验结果显示空仓态、新粮态、通风态的查准率分别为78%、74%、91%,查全率分别为82%、70%、88%。试验结果表明基于历史粮温统计特征的粮仓库存状态检测方法能够较好的实现对空仓态和通风态的检测,能够基本实现对新粮态的检测。