细胞因子IL-17作为牛结核病诊断标志物的研究及实时荧光定量PCR检测方法的建立

试验旨在评价细胞因子IL-6和IL-17 mRNA转录水平与牛分枝杆菌感染之间的关系,及其在牛结核病诊断中的应用潜力。通过皮内变态反应试验和IFN-γ释放试验临床筛选结核病阳性牛和结核病阴性牛,采集试验动物抗凝全血,分离、收集外周血淋巴细胞,分别用牛结核菌素（PPD-B）、禽结核菌素（PPD-A）、重组蛋白CFP-10-ESAT-6（CE）、pET-32a载体标签蛋白（PET）或PBS 37℃培养6 h,用实时荧光定量PCR检测细胞因子IL-6、IL-17和IFN-γ的mRNA相对转录水平。结果显示,PET和空白对照PBS类似,不能刺激细胞因子mRNA转录水平的提高,表明CE中包含的PET对试验的影响可忽略不计;牛外周血淋巴细胞经PPD-B、PPD-A或CE刺激后,结核病阳性牛样品中IL-17和IFN-γ的mRNA转录水平均显著高于结核病阴性牛（P<0.05）,其中PPD-B刺激效果强于CE和PPD-A,而CE刺激的特异性更好;选取CE作为最佳刺激源,结果显示,IL-17和IFN-γ的mRNA转录水平之间相关性良好（spearman r=0.79）,并初步建立了基于IL-17和IFN-γ转录水平的实时荧光定量PCR检测方法;以此方法对14头结核病阳性牛进行临床检验,IL-17实时荧光定量PCR法的阳性样本检出率为85.7%,高于IFN-γ（71.4%）。本研究结果初步表明,牛分枝杆菌特异性抗原（PPD-B、CE）诱导的IL-17 mRNA转录水平与牛结核病相关,以CE为刺激源建立的IL-17实时荧光定量PCR检测方法具有用于牛结核病诊断的潜力。     

土壤紧压导致绿化树生长不良的间接诊断原理与实例

在城市中,土壤紧压是导致绿化树生长不良的重要原因,但现场环境和成本因素限制了利用植物和土壤的理化指标来直接诊断两者的关系。文章总结土壤紧压间接诊断的原理,并结合实例进行分析。     

Determinants of the degradation of soil structure in vineyards with a view to conversion to organic farming

In perennial crops such as grapevine, there is a considerable risk of soil degradation caused by mechanization. Organic farming may increase traffic and result in more intensive soil structure degradation, especially on wet soil. Soil structure was observed in 69 soil profiles from 12 vineyards (Languedoc‐Roussillon, Bordeaux, Provence, Burgundy, Rhône Valley) to study the relationships between permanent soil characteristics (texture, stoniness, waterlogging), cultivation practices (technical operations, traffic, farm equipment) and soil structure. Compaction zones were identified in soil profiles viewed perpendicularly to the grapevine rows. The percentage of compacted area and a score for compaction intensity were assessed in the top 0.5 m of the soil profile in three soil compartments defined by the distance from the grapevine row: (1) 0 to 0.2 m (2) 0.2 m to 0.5 m and (3) 0.5 m to the middle of the inter‐row. Most soil profiles exhibited considerable compaction: 75% of the soil profiles were compacted in compartments 2 or 3. Intensity correlated with depth of compaction in compartment 2 – the deeper the compaction, the greater the compaction intensity. Four types of soil profiles could be identified, depending on the location of compacted zones and of their intensity of compaction. The factors that determined the types of soil profiles were as follows: soil vulnerability to compaction, use of moderating practices (practices that limit the risk of compaction) and traffic geometry. A statistical analysis resulted in a decision tree that provides a useful basis to choose cultivation practices that limit damage to or improve soil structure.     

猪毛滴虫病的研究进展

毛滴虫是猪体内较为常见的原虫,目前有关猪毛滴虫的报道较少,其兽医公共卫生学意义尚未确定。文章就猪毛滴虫的分类地位、虫体形态、生活史、致病性、流行病学情况、诊断、防治等方面的内容作一综述,为猪毛滴虫和毛滴虫病的研究提供参考。     

玉米种植一机配两具经典模式研究

分析玉米种植优质高效一机配两具经典摸式的整体技术，探讨主机、收获机和联合耕整机的动力及机型选择。根据生产实践及技术发展趋势，对现有的玉米收获机和联合耕整机进行改进设计，弥补原机具设计上的不足，使机具的技术水平有了很大提升。     

Leaf color diagnosis and nitrogen management for winter wheat “Kitanokaori” in Hokkaido

(Jpn. J. Soil Sci.Plant Nutr., 77, 293–298, 2006)

“Kitanokaori” is a new variety of wheat for bread use bred at the National Agricultural Research Center for Hokkaido Region. The grain protein content of wheat for bread use should be higher than 120 g kg?1. Much nitrogen application is necessary to obtain high grain protein content. Therefore, it is necessary to determine the optimum amount of nitrogen to obtain the required protein content and to prevent nitrogen from remaining in the soil. The nutrition diagnosis using leaf color was investigated to predict the need and the amount of top-dressing. Field experiments were conducted for four years with nitrogen treatments in Andosol, which has moderate nitrogen fertility, and in Histosol, which is a fertile soil. The leaf color was measured using a chlorophyll meter SPAD502 (CM value) at the middle part of the leaf, avoiding the center rib. The colors of the 10·15 uppermost second leaves were measured in one plot and averaged.

A close relation was found between leaf color at the full heading stage and grain protein content at harvest. Leaf color at the full heading stage is therefore a good index to control the protein content. Considering the effect of top-dressing at the full heading stage in each CM value, the diagnosis criterion was decided. When the CM value is over 52 at the full heading stage, more nitrogen application is not needed. When the CM value is 50·52, 30 kg N ha?1 of top-dressing at the full heading stage is needed, and when the CM value is 45·50, 60 kg N ha?1 of top-dressing is needed to obtain a grain protein content of more than 120 g kg?1.     

离心泵弹性柱销联轴器不对中振动特性研究

简化建立一种离心泵机组联轴器不对中的振动模型,并建立数学模型,依据动力学基础知识推导振动方程。结合实测离心泵实验台的轴承振动数据,分析离心泵机组联轴器不对中的振动特性,并提出相应的故障诊断方法。