不同区域奶牛子宫内膜炎病原菌的分离鉴定及分布特征

【目的】对中国6个区域奶牛子宫内膜炎病原菌的种类和区域分布特征进行研究,为筛选出最佳治疗药物以减少子宫内膜炎对畜牧业造成经济损失提供数据支持。【方法】分别从赤峰区域、张家口区域、潍坊区域、重庆区域、宝鸡区域和北京区域选择不同规模的奶牛养殖场中患子宫内膜炎的奶牛,用采样器每个区域采集60份(6个区域共计360份)患病牛的子宫内容物,通过革兰氏染色和生化鉴定的方法鉴定分离纯化的奶牛子宫内膜炎病原菌,并分析病原菌的分布特征。【结果】潍坊、赤峰、北京区域引起奶牛子宫内膜炎以单一感染为主。宝鸡、张家口、重庆区域引起奶牛子宫内膜炎以混合感染为主。赤峰、重庆、张家口、潍坊、宝鸡、北京区域引起奶牛子宫内膜炎的病原菌以革兰氏阳性菌为主。赤峰奶牛子宫内膜炎的主要致病菌是葡萄球菌。重庆奶牛子宫内膜炎的主要致病菌是链球菌。张家口奶牛子宫内膜炎的主要致病菌是大肠杆菌。潍坊奶牛子宫内膜炎的主要致病菌是链球菌。宝鸡奶牛子宫内膜炎的主要致病菌是葡萄球菌。北京奶牛子宫内膜炎的主要致病菌是蜡样芽孢杆菌。     

Critical Periods of Storage of the Greenhouse Gases in Polypropylene Syringe

It is convenient to store gas samples containing e.g. carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O), in polypropylene syringes before chromatographic analysis. However, there is no study of the integrity of these samples or of what storage condition may be critical. To investigate we filled polypropylene syringes with two standard mixtures of CO₂, CH₄, and N₂O, and stored them at ~2 °C and ~25 °C, and analyzed the contents using gas chromatography. Our results suggest that the storage of gases on the syringe at room temperature is not viable due the CO₂ storage integrity when in low concentration. However, the quantitative integrity of samples is maintained when the syringe is kept refrigerated up to 19 h, period limited by CO₂ and CH₄, taking into account the three gases CO₂, CH₄, and N₂O.     

Do water dynamics and land use in riparian areas change the spatial pattern of physical–mechanical properties of a Cambisol?

Precision Agriculture - Changes in land use in riverside ecosystems added to the flood and ebb regimes of rivers modify the spatial variability of the physical–mechanical attributes of soil,...