Primary sulfates in atmospheric sulfates: estimation by oxygen isotope ratio measurements

The relative amounts of primary and secondary sulfates in atmospheric aerosols and precipitation can be estimated from measurements of the stable oxygen isotope ratios. The oxygen-18 content of sulfates formed in power plant stack gases before emission into the atmosphere is significantly higher than that of sulfates formed from sulfur dioxide after emission. Results show that 20 to 30 percent of the sulfates in rain and snow at Argonne, Illinois, are of primary origin.     

醉马草的有毒成分研究

本研究用溶剂提取法和阳离子交换树脂法首次从醉马草中提取、分离出一种生物碱成分,我们称其为醉马草毒素。动物毒性试验证明,醉马草毒素是醉马草的主要有毒成分。经元素分析及有机波谱分析确定了结构式。 马属动物按照10g/kg体重的剂量,一次灌服醉马草干粉或相当剂量的粗提物,即可引起与自然发病相同的急性中毒。症状主要表现为精神极度沉郁、翘尾,四肢无力,行走如醉,肌肉震颤,心跳加快,呼吸迫促等。     

Organic zinc and copper supplementation on antioxidant protective mechanism and their correlation with sperm functional characteristics in goats

Trace minerals feeding had significant effects on sperm production and fertility with better absorption and proper utilization within the body for optimum reproductive function. Several studies have shown that more influenced trace elements in the diets of animals are copper (Cu) and zinc (Zn). Bucks showing deficiency of this mineral might affect the quality of semen production which in turn would affect the fertility. This experiment was thus designed to test the effects of organic Cu and Zn supplementation on antioxidants enzyme activities and sperm functional attributes in fresh semen of bucks. Forty bucks (n = 40, Aged 5 months) were assigned to ten groups of four animals in each group, supplemented (for a period of 8 months) with different levels of organic Zn: 20 mg (T2), 40 mg (T3) and 60 mg (T4), organic Cu: 12.5 mg (T5), 25 mg (T6), 37.5 mg (T7) and combined organic Zn and Cu: 20 + 12.5 mg (T8), 40 + 25 mg (T9), 60 + 37.5 mg (T10), respectively, per kg dry matter and no additional mineral diet (control; T1). One hundred and sixty semen samples were collected through electro‐ejaculator and analysed for sperm quantity, quality, acrosome intactness and plasma membrane integrity and correlated with the catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase enzyme activities in seminal plasma. The results indicated organic Cu and zinc supplemented bucks produced more sperm cells, had higher sperm concentrations, maintained higher (p < .01) sperm livability, plasma membrane and acrosome integrities, more motility and velocity. The increased antioxidant enzyme activities, reduced oxidative stress and lowered lipid peroxidation were positively correlated (p < .05) with the sperm functional attributes. In conclusion, organic Cu and Zn supplement to male goats showed protective roles against oxidative damage and maintained better fresh semen characteristics.     

云贵川三省部分地区警犬狂犬病血清中和抗体调查

为评价警犬的狂犬病免疫效果,了解影响免疫效果的因素,2017年在云南、贵州、四川三省部分地区免疫狂犬病疫苗的警犬中随机抽样,采用荧光抗体病毒中和试验(FAVN),检测血清中狂犬病病毒中和抗体效价。结果显示,共抽检187只警犬,中和抗体阳性127只(≥0.50 IU/m L),总体免疫合格率为67.91%,其中云南、贵州、四川3省的免疫合格率分别为57.14%、68.33%、76.06%。结果分析表明,警犬狂犬病免疫合格率与犬的年龄、免疫次数、疫苗类型等因素有关,而与性别和品种无关。建议完善警犬免疫程序,加大血清中和抗体监测力度,对不合格警犬及时加强免疫;对每个影响因素进行连续性分析,以确定影响警犬狂犬病免疫合格率的具体因素。     

2018年山东省诸城市小反刍兽疫免疫效果横断面调查

为掌握山东省诸城市小反刍兽疫的免疫效果,2018年6月采用横断面研究方法,对该市规模场和自然村（散养户）饲养羊只进行小反刍兽疫免疫效果评估。采用两阶段随机抽样方法,结合部分便利抽样,采集580份羊血清样品进行ELISA 抗体检测。结果显示：合格样品560份,合格率达96.5%;14个规模场均免疫合格,群体合格率达到100%;在抽检的16个自然村中,15个村免疫合格。结果表明,诸城市小反刍兽疫总体免疫效果良好。