Effect of the nitrification inhibitor DMPP on nitrous oxide emissions and the stabilization of ammonium following the injection of dairy slurry and digestate in a soil‐column experiment

Injection of slurry or digestate below maize seeds is a relatively new technique developed to improve nitrogen use efficiency. However, this practice has the major drawback of increasing nitrous oxide (N₂O) emissions. The application of a nitrification inhibitor (NI) is an effective method to reduce these emissions. To evaluate the effect of the NI 3,4‐dimethypyrazole phosphate (DMPP) on N₂O emissions and the stabilization of ammonium, a two‐factorial soil‐column experiment was conducted. PVC pipes (20 cm diameter and 30 cm length) were used as incubation vessels for the soil‐columns. The trial consisted of four treatments in a randomized block design with four replications: slurry injection, slurry injection + DMPP, digestate injection, and digestate injection + DMPP. During the 47‐day incubation period, N₂O fluxes were measured twice a week and cumulated by linear interpolation of the gas‐fluxes of consecutive measurement dates. After completion of the gas flux measurement, concentration of ammonium and nitrate within the soil‐columns was determined. DMPP delayed the conversion of ammonium within the manure injection zone significantly. This effect was considerably more pronounced in treatment digestate + NI than in treatment slurry + NI. Regarding the cumulated N₂O emissions, no difference between slurry and digestate treatments was determined. DMPP reduced the release of N₂O significantly. Transferring the results into practice, the use of DMPP is a promising way to reduce greenhouse gas emissions and nitrate leaching, following the injection of slurry or digestate.     

Effects of rearing stress on Atlantic salmon (Salmo salar L.) antibody response to a non-pathogenic antigen

This study was carried out to test the effects of acute stress on the primary and the secondary antibody responses in Atlantic salmon (Salmo salar L.). Fish received a primary immunization with sheep red blood cells (SRBC) and received a second immunization 11 weeks later. At priming, a group of fish was stressed by water level reduction for 30 min (moderate stress), and another group was stressed severely by applying the stressor twice, with an interval of 6 h, 3 days in a row (severe stress). At the time of the booster, another two groups of previously unstressed, primed fish were treated likewise. Unstressed fish mounted a primary antibody response to SRBC and a secondary response, which was improved compared with the primary response., The primary antibody response against SRBC was impaired by severe, but not moderate, acute stress at priming, whereas the secondary antibody response was unaffected. Both moderate and severe stress at the time of the booster was immunosuppressive in fish that had been primed under non‐stress conditions. It is concluded that cortisol release as a result of stress exposure is most immunosuppressive at the time of the second immunization.     

新城疫病毒F基因疫苗接种剂量的研究

以新城疫病毒F基因的cDNA与真核表达载体pcDNA3重组 ,构建了新城疫病毒F基因疫苗。采用不同剂量接种SPF鸡后 ,通过抗体监测和强毒攻击试验 ,分析了其诱导的体液免疫应答及免疫保护作用。结果表明 ,接种剂量为1 0 0 ,2 0 0ug时 ,试验鸡在免疫后第 2周出现较明显的抗体反应 ,接种剂量为 1 0ug时抗体变化不明显。以标准强毒F4 8E9攻击后 ,空白对照组及接种剂量为 1 0 ,1 0 0ug组的鸡只全部发病死亡 ,未获得免疫保护 ;而 2 0 0ug组鸡只 30 %存活 ,获得部分免疫保护。表明基因免疫效果与接种的剂量有密切的关系     

The fate of tree root and pruning nitrogen in a temperate climate alley cropping system determined by tree-injected 15N

 Nitrogen (N) fluxes through the major plant pools of an alder (Alnus sinuta)-sweet corn (Zea mays) alley cropping system were determined over the course of two cropping seasons. Alder trees were injected with ¹⁵NO₃–N to directly follow the flow of N between alder and corn. The contribution of the above- and below-ground tree N to corn was determined by exchanging the labeled above-ground prunings (green manure) with those from unlabeled plots. During the first growing season after coppicing of the injected alders, 18% of the alder ¹⁵N was taken up by the corn with 12% coming from the above-ground prunings. Of the ¹⁵N remaining in the tree/stump following coppicing, the majority was recovered by corn plants within the rows next to the labeled trees during the first growing season. Earlier recovery of ¹⁵N by corn in the labeled root plots compared to the labeled pruning plots indicated the importance of root turnover in supplying N to corn, especially following coppicing. By the end of the first and second growing seasons, 34% and 38% of the ¹⁵N initially present in prunings was recovered in corn plants, respectively. Approximately 80% of the total injected ¹⁵N was found in the soil during the second growing season; however, the turnover of above- and below-ground alder components supplied only 3–4% of the N required by corn during the year of green manure application. Thus, most of the corn N demand was met by mineralization of residual soil N within the 2 years of coppicing and green manure additions. Continued internal cycling of tree N and movement of soil N into more labile pools would presumably allow more alder N to become available over time. The synchronization between N mineralization from the hedgerow green manure components and nutrient uptake of the alley crop remains a major challenge in alley cropping and other green manure systems. Received: 9 April 1999     

三种有机溶媒制备土霉素注射液的稳定性试验

采用甘油甲缩醛、二甲基乙酰胺、聚乙烯吡咯烷酮K30三种有机溶媒为主,经特殊制备工艺制成长效土霉素注射液样品,在前期获得满意的刺激性试验与临床治疗效果基础上,进行了为期两年的常温条件下制剂含量、外观色泽、澄明度、pH值、鉴别反应等质量指标试验观察,为药品的生产制造提供理论依据。结果表明:不同有机溶媒配比样品的稳定性均好,符合进口兽药质量标准要求,但以甘油甲缩醛、二甲基乙酰胺和注射用水溶媒联合使用,制剂成本最低。     

2014-2016年河南省猪伪狂犬野毒感染和免疫情况血清学调查

调查河南省猪群伪狂犬野毒感染流行情况,为制订合理的防控与净化策略提供参考依据.于2014年1月-2016年5月,采集河南省不同地域780个猪场16 200份血清样本,使用gE-ELISA鉴别诊断方法进行血清学调查,对10个阳性稳定猪场和10个阳性发病猪场进行血清学分析,对2个后备母猪培育场(1个为阴性场,另1个为阳性场)进行生产成绩分析,同时对猪场伪狂犬gE基因缺失疫苗使用情况进行调查,并跟踪了40个猪场的疫苗免疫情况.结果显示,河南省猪场伪狂犬gE抗体阳性率90.0％,血清样本阳性率46.2％,成年种猪阳性率53.1％,后备种猪阳性率27.6％.猪群在阳性发病场的阳性率高于在阳性稳定场的阳性率,育肥猪感染带毒严重影响其生产成绩,猪场伪狂犬疫苗免疫强度呈现增加趋势.综上可知,目前河南省猪群伪狂犬野毒感染情况比较严重.     

油田注水高压变频技术的节能分析

针对油田注水系统存在不稳定、能耗大等问题，制定了在注水系统中增加高压变频设备的措施，对高压变频技术在辽河油田的实际应用情况进行经济性分析，指出采用高压变频技术不仅解决了油田注水难的问题，而且取得了明显的节能效果。     

不同抑郁模型大鼠行为学及神经营养因子表达的对比研究

目的 对比分析不同抑郁模型大鼠的生物学特点,为抑郁模型研究提供实验依据。方法 40只SD大鼠随机分为空白对照组、溶媒对照组、束缚应激组、慢性不可预见性温和应激（chronic unpredictable mild stress,CUMS）组,皮质酮注射组,每组8只。除对照组外,各组分别进行造模,时间均为21 d,造模结束后采用Morris水迷宫测试、旷场实验、强迫游泳实验检测大鼠的抑郁样行为,蛋白印迹法检测大鼠海马和前额叶皮质区脑源性神经营养因子（brain-derived neurotrophic factor,BDNF）、神经生长因子（nerve growth factor,NGF）的含量。结果 与对照组比较,3种模型组大鼠逃避潜伏期时间均显著增加（P<0.01）,但只有皮质酮组大鼠进入目标象限潜伏期时间增加（P<0.05）;旷场测试中活动次数显著下降,其中CUMS组和皮质酮组对比束缚组有显著差异（P<0.01）;同时,3种模型组大鼠强迫游泳中的不动时间均显著增加（P<0.01）;此外,与对照组比较,各模型组大鼠海马和前额叶皮质区BDNF、NGF表达均显著下降（P<0.01或P<0.05）,但各模型组之间相互比较,差异无统计学意义（P>0.05）。结论 慢性束缚应激、CUMS、慢性皮质酮注射均能使大鼠产生明显的抑郁样行为,且在脑内神经营养表达上差异无统计学意义。     

编码草鱼呼肠孤病毒VP5与NS38B细胞表位的DNA疫苗壳聚糖纳米口服制剂的研制与评价

以编码II型GCRV VP5和NS38的B细胞线性表位的cDNA串联构建pcDNA3.1(+)-Bs5-10（GenBank登录号为MH234474）,并包被成纳米级壳聚糖颗粒;无GCRV草鱼（11~12 cm、25~30 g）随机分为空白对照组、空白对照-GCRV攻毒组、裸空载体注射组、壳寡糖包被空载体口服组、裸DNA疫苗注射组（每尾鱼注射10 μg载体,1 d和29 d各免疫1次）、壳寡糖包被DNA疫苗口服组（每尾鱼大约投喂50 μg载体,1～3 d、15～17 d和43～45 d各口服免疫1次）,在28℃水温下评价疫苗保护力和特异性抗体水平。结果显示,裸DNA疫苗注射组和壳寡糖包被DNA疫苗口服组的相对保护率分别为66.67%和50%;两组血清抗VP5和抗NS38的IgM水平均随加强免疫而显著升高（P<0.05）;且在对应时间点（22 d或50 d）,前组特异性IgM水平均显著高于后者（P<0.05）。结果表明,壳聚糖包被的DNA疫苗口服免疫能在一定程度上抵抗GCRV攻击,且体液免疫参与了该保护机制。     

运动康复联合参附注射液对心肌病心衰大鼠血流动力学的影响

目的 观察运动康复联合参附注射液对心肌病所致心力衰竭大鼠血流动力学的影响。方法 将50只SD雄性大鼠随机分为安静对照组（10只）与造模组（40只）,造模组大鼠采用盐酸多柔比星腹腔注射7周造模,造模成功后的36只大鼠,按随机数字表法,分为模型组、参附组、运动康复组、运动康复参附组,每组9只。分别用生理盐水、参附注射液、运动康复、运动康复联合参附注射液干预4周,检测大鼠左室收缩压峰值（LVSP）、左舒张末压力（LVEDP）、左室等容收缩末期压力上升最大速度（+dp/dtmax）、左室压力下降最大速度（-dp/dtmax）等血流动力学指标。结果 与模型组比较,参附组、运动康复组、运动康复参附组在LVSP、LVEDP、+dp/dtmax、-dp/dtmax差异有统计学意义（P<0.05）;与运动康复参附组比较,参附组、运动康复组在LVSP、+dp/dtmax、-dp/dtmax差异有统计学意义（P<0.05）;与运动康复参附组比较,参附组在LVEDP差异有统计学意义（P<0.05）。结论 运动康复、参附注射液、运动康复联合参附注射液都能改善心衰大鼠血流动力学指标,提高心衰大鼠心脏功能,而运动康复联合参附注射液效果最好。