Seroprevalence of porcine and human influenza A virus antibodies in pigs between 1986 and 1988 in Hassia

1,268 sera collected from slaughtered pigs in Hassia (FRG) from 1986 to 1988 were tested for antibodies against porcine and human influenza A virus strains using the single radial haemolysis test (SRHT). Antibodies against the porcine strains (subtype H1N1) A/Swine/Arnsberg/1/81, A/Swine/Iowa/15/30 and A/New Jersey/7/76 were detected in 411 (32.4%), 318 (25.1%) and 304 (24.0%) of sera, respectively. Up to 1988 a slight increase (10%) in the seroprevalence to A/Swine/Arnsberg/1/81 was noticed, whereas the results obtained with the other strains showed little variation. Antibodies against the human H1N1 strain A/Singapore/6/86 were only found in sera collected 1987 and 1988 in rates of 1.6% and 3.0%. Serological indication of infections with the human H3N2 strains A/Victoria/1/75, A/Hong Kong/1/68 and A/Philippines/2/82 could be shown in 286 (22.6%), 178 (14.4%) and 135 (10.6%) of the serum samples. Within the three year period the rate of sera positive for antibodies against A/Philippines/2/82 increased from 6.5% to 23.0%, whereas no variation in the rates were found using the other H3N2 strains. Antibodies simultaneously against porcine (H1N1) and human (H3N2) virus strains were detected in 9.9% of all sera tested.     

挤压蒸煮大麦作啤酒辅料的糖化试验研究

采用二次正交旋转组合试验方法,研究了作啤酒辅料的大麦挤压蒸煮系统的模孔孔径、套筒温度、大麦含水率、螺杆转速和模板内表面至螺杆末端端面的距离,对醪液的主要考察指标——麦汁的过滤速度、碘值、浸出物收得率的影响规律。研究表明,挤压蒸煮大麦可以作啤酒辅料,且麦汁浸出物收得率为72．04％,高于传统不挤压大麦辅料的麦汁浸出物收得率。     

燃料添加剂对均质压缩燃烧影响的试验

在一台改造的4缸柴油机的第4缸进行均质压燃（HCCI）燃烧试验,研究了添加剂对HCCI燃烧过程的影响。试验结果表明,在HCCI燃烧稳定工况下,没有添加剂的基础燃料PRF90（相当于90号汽油）着火滞后,燃烧放热峰值低,而混有添加剂的基础燃料则着火明显提前,燃烧放热峰值升高。在相同循环喷油量和相同转速的条件下,随着添加剂质量分数的增加,HCCI着火和燃烧放热提前,燃烧放热峰值提高,但过高的添加剂质量分数会使得发动机爆震,工作粗暴。     

自然吸气与增压中冷柴油机气缸套应变对比

采用应变片测试技术,对自然吸气和增压中冷柴油机湿式缸套在外特性工况下工作时的周向应变进行了动态测试,拟合出缸套工作时的周向变形曲线,对比分析了不同机型湿式气缸套工作变形的特点以及主要影响因素。研究结果表明,随转速的提高,自然吸气柴油机缸套主推力面应变随之增加,逐渐呈现一种振动特性;而转速提高对增压中冷柴油机缸套周向应变影响不明显,缸套主推力面应变最大值出现在各作用力对缸套壁面作功最多的额定扭矩工况。     

植被信息提取过程中ETM+遥感影像融合和分类试验

利用HIS、PCA、Brovey及小波变换4种图像融合方法对南京地区植被信息提取过程中ETM 遥感影像进行融合和分类试验。从信息量、高分辨率信息的融入度和分类精度三方面,对融合图像进行光谱质量和空间结构信息的定量评价。试验结果表明,Brovey变换更适合植被信息提取时的ETM 图像融合,并能够较明显提高影像的分类精度。     

STEAM教育理念在竹木玩具创新设计中的应用

随着技术发展和教育理念的变革,家长对儿童玩具提出了更高要求,于是基于STEAM(Science, Technology, Engineering, Arts, Mathematics)教育理念研发的玩具应运而生。文章运用市场调研和归类分析的方法,调查了国内市场上STEAM玩具的现状。结果发现,市场上现有的STEAM玩具设计普遍存在缺失原创性、独特性、运动性以及使用材料的环保性等问题,为此提出了竹木STEAM玩具设计应注重本土化、微课程化、环保化以及互动化的建议,并以此设计了一款竹制STEAM玩具。     

菌核净、代森锰锌及其混剂对烟草赤星病菌毒力测定

运用Horsfall毒力试验设计方案和孢子萌发抑制法分别测定菌核净、代森锰锌及其混剂对烟草赤星病菌(Alternaria alteranta)的毒力，并分别用Wadley方法、Gowing方法、Abbott方法和孙云沛方法等多种评价方法评价所配混剂的增效作用，结果表明，当它们按EC50剂量7：3的比例混配时所得混剂表现明显的增效作用．4种增效作用评价方法所得结果一致，田间防治结果也证明该混剂可有效防治赤星病。     

通过考核认证提高警犬实战技能

2006年,辽宁省公安厅作为片区警犬资格认证的试点单位,分别于5月17日至6月12日、11月8日至9日,两次集中组织进行了警犬资格认证考核。全省公安机关共有133头警犬参加考核,占全省163     

对羟基苯甲酸和肉桂酸对巨尾桉9号苗木生长及生理指标的影响

采用基质栽培试验,研究对羟基苯甲酸、肉桂酸对3月生巨尾桉9号苗木生长及叶片抗氧化酶活性的影响,结果表明：对羟基苯甲酸各处理浓度（10、50、100、500 mg/L）下的苗高增长量、地径增长量均显著高于对照,且在10 mg/L时,苗高增长量最大,为52.33 cm;肉桂酸10 mg/L时巨尾桉苗木苗高增长量较对照高,且随着其浓度的增加,苗高增长量和地径增长量均逐渐降低。对羟基苯甲酸、肉桂酸各浓度下巨尾桉9号苗木叶片叶绿素总含量均极显著低于对照,丙二醛含量略高于对照;对羟基苯甲酸、肉桂酸各浓度对巨尾桉9号叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、多酚氧化酶（PPO）活性均具有一定的影响。对羟基苯甲酸10、50、100 mg/L及肉桂酸10 mg/L处理下的综合化感效应指数为正,对羟基苯甲酸500 mg/L及肉桂酸50、100、500 mg/L处理下的综合化感效应指数为负。可见,对羟基苯甲酸、肉桂酸对巨尾桉9号苗木的生长具有“低浓度促进、高浓度抑制”的规律,拐点浓度分别为100、10 mg/L;且在处理浓度相同时,肉桂酸的化感作用较对羟基苯甲酸强。     

Anatid herpesvirus 1 CH virulent strain induces syncytium and apoptosis in duck embryo fibroblast cultures

Anatid herpesvirus 1 (AHV-1) CH virulent strain was first isolated from an infected duck and it was found that this virus strain could induce cytopathic effect (CPE) in duck embryo fibroblast (DEF). Following AHV-1 infection, DEF showed morphological changes such as cell rounding, improved refractivity and detachment from the culture surface. However, its pathological characteristics were not adequately known. Related studies were performed and the results showed that syncytium formation could be observed as the other type of CPE in AHV-1 infection. Hematoxylin-eosin staining and 4’, 6-diamidino-2-phenylindole (DAPI) staining of infected DEF were each used to visualize the shape and distribution of chromatin within nuclei and nuclear fragmentation was observed. Chromatin condensation and margination, as well as formation of apoptotic bodies were observed by transmission electron microscopy (TEM). DNA ladder formation was detected in AHV-1 infected cells and apoptosis of the infected DEF was also detected by flow cytometry analysis of Annexin V-FITC/PI staining method. Therefore, it was suggested that AHV-1 virulent strain can induce syncytium and apoptosis in DEF. Syncytium formation and apoptosis observed in this study may contribute to the elucidation of AHV-1 pathogenesis.