Mycoplasma leachii causes bovine mastitis: Evidence from clinical symptoms,histopathology and immunohistochemistry

Twelve quarters of six lactating cows were inoculated with Mycoplasma leachii strain GN407 through intramammary ductal infusion; another 12 quarters were inoculated with heat-inactivated M. leachii culture medium as negative controls. Multidisciplinary procedures, including clinical assessment, etiology assessment, pathology and immunohistochemistry (IHC), were used to elucidate the pathogenicity of M. leachii in bovine mastitis. From post-inoculation days (PIDs) 3 to 9, 12 inoculated quarters developed mild to severe clinical mastitis and mammary tissue histopathological changes, including inflammatory cell infiltration and architectural destruction of mammary gland ducts. The M. leachii antigen was also detected by IHC in the mammary gland epithelial cells of the inoculated quarters as a weak signal on PID 6 and as a strong signal on PID 9. The control quarters also developed mild mastitis and histopathological changes on PID 9, and M. leachii was also detected by IHC. Throughout the experimental period, the quarters of the negative control cow were clinically and pathologically normal, and the M. leachii antigen was not detected. In conclusion, direct histological and immunohistochemical evidence confirmed that M. leachii causes clinical bovine mastitis through histopathological lesions induced by invasion of the pathogen into mammary gland cells and through inflammatory cell infiltration.     

双（三环己基锡）四氯邻苯二甲酸酯的合成、表征和晶体结构的测定

合成了双（三环己基锡）邻苯二甲酸酯Cl4C6（CO2Sn（C6H11）3）2,利用元素分析仪和IR表征了其结构。通过X-射线单晶衍射仪,测定了该配合物的晶体结构。该化合物晶体属单斜晶系,空间群P-1,a=14．5522（13）,b=13．3651（12）,c=34．006（3）（^°A）,β=97．8990（10）°,Z=4,V=6551．2（10）nm^3,R=0．0603,Rw=0．1287,S=1．185。该分子是通过苯环桥联的双核有机锡化合物,分子中的两个锡原子均为畸变的四面体构型。     

小麦条锈病气象等级预测方法研究(英文)

[Objective] The aim of this study is to establish the model for forecasting wheat stripe rust occurrence condition using meteorological factors. [Method] Based on the data of wheat stripe rust occurrence degrees in its past prevalent years and the meteorological data at corresponding periods, the methods of grey correlation analysis and fuzzy mathematics were employed to establish the forecast model for four pathogenesis indices according to the time sequence before winter, Early March, Early April and Middle May. Thus, the criterion for forecasting the occurrence degree of wheat stripe rust was obtained based on the distribution method of arithmetic progression. [Result] The model corresponding to meteorological conditions for forecasting wheat stripe rust was successfully established. According to the verification, the forecasting results before winter and in Early Mar. were more severer than the real occurrence condition, while the forecasting results in Early Apr. and Middle May were basically consistent with real values. [Conclusion] The results of the present study may avail the control of wheat stripe rust in Henan Province.     

昭苏马场不同草地类型土壤养分特征研究

分别对昭苏马场的不同草地类型做了土壤养分测定,结果表明:亚高山草甸的土壤有机质含量最高,冲积平原草甸的土壤有机质含量最低;土壤全氮含量表现为中山山地草甸最高,低山丘陵草原最低;而土壤全钾含量正好相反,低山丘陵草原的土壤全钾含量最高,中山山地草甸最低.亚高山草甸草地土壤全磷、速效氮的含量较丰富,其他各草地类型间土壤全磷分布较均匀;山前冲积平原草甸的土壤速效氮含量最低,各草地类型之间土壤速效磷的含量变化也不大,而且速效磷在各层中分布的比较均匀.中山山地草甸的土壤速效钾含量最高,亚高山草甸的最低.各草地类型土壤养分随土层深度增加,有逐渐下降的趋势.土壤有机质、全磷、速效氮含量差异均不显著(P>0.05),土壤全钾和0～10 cm速效钾含量差异极显著(P<0.01).     

大豆降压肽的生产工艺研究

应用4种蛋白酶酶解大豆分离蛋白,研究其水解效果和降压活性。实验选定碱性蛋白酶为生产大豆降压肽的最适酶,并对其酶解条件进行了优化,确定生产大豆降压肽的最佳条件为：温度60℃,pH8.0,底物浓度4%,碱性蛋白酶浓度4%,水解度14.4%,优化后的ACE抑制率可达到84.1%。     

广东省6种常见食用菌的重金属含量调查与评价

广东省6种常见食用菌重金属的平均含量为:铅>镉>汞>砷,均低于国家食用菌卫生限量标准GB7096-2003,说明食用菌的重金属含量是安全的。食用菌品种不同,其重金属的含量差异很大,铅、镉、汞、砷的平均累积量依次为:香菇>金针菇>平菇>鸡腿菇>草菇>灵芝,全部符合国家卫生标准的要求。值得注意的是,食用菌重金属含量的变异系数较大,说明环境、品种和栽培技术影响重金属在食用菌中的积累。采用优良品种、选择安全的生产环境、优化栽培技术可降低食用菌的重金属含量。     

稻壳在日光温室西葫芦有机基质栽培中的应用研究

以早青一代西葫芦为试材,研究了以稻壳、鸡粪和大田土壤按不同比例构成的基质配方对西葫芦生长、果实产量和品质的影响。结果表明,以稻壳∶鸡粪∶大田土壤为3∶1∶1的配方栽培的西葫芦表现优异,适宜于生产应用。     

崂山绿茶水溶性氟含量及其影响因素分析鲻

通过采样分析,对崂山绿茶水溶性氟含量及其主要影响因素进行了研究。结果表明,崂山绿茶水溶性氟含量与茶园土壤水溶性氟含量、土壤pH值和土壤速效磷含量的相关性达到极显著水平,与灌溉水pH值的相关性达到显著水平;土壤水溶性氟含量与土壤pH值和土壤速效磷含量的相关性达到极显著水平。     

大骨鸡快慢羽群体系谱完整性分析

利用系谱完整性指数(Pedigree Completeness Index,PCI)统计分析辽宁庄河大骨鸡快慢羽群体系谱的完整情况。结果显示,庄河大骨鸡的系谱完整性较好(PCI为0.92±0.18);对于系谱的完整性,快羽群体(PCI为0.88±0.23)与慢羽群体(PCI为0.94±0.15)之间不存在明显差异。