Protective efficacy of an H5/H7 trivalent inactivated vaccine produced from Re-11, Re-12, and H7-Re2 strains against challenge with different H5 and H7 viruses in chickens

We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5 N6)(DK/GZ/S4184/17)(a clade 2.3.4.4 d virus), A/chicken/Liaoning/SD007/2017(H5 N1)(CK/LN/SD007/17)(a clade 2.3.2.1 d virus), and A/chicken/Guangxi/SD098/2017(H7 N9)(CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7 N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7 N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.     

Differential regulation on C5 expression in goose versus mammals by glucose/palmitate provides a potential protection for goose fatty liver

Goose fatty liver is a specific type of nonalcoholic fatty liver that is protected from harmful effects associated with severe steatosis. Our previous findings suggest that suppression of the complement C5 may be relevant, but the mechanism is unclear. Therefore, in this study, we first verified the expression pattern of complement genes (including C5) during goose fatty liver formation and then determined the liver fat content and fatty acid composition by high-performance liquid chromatography (HPLC), followed by selecting the differential metabolites to treat HepG2, goose and mouse primary hepatocytes, aiming to explore the mechanism of C5 and inflammation suppression in goose fatty liver. The data confirmed the suppression of complement genes (including C5) in goose fatty livers. Moreover, fat content was significantly higher in fatty liver versus normal ones, with oleic acid and palmitic acid dominantly accounting for the difference. In line with this, high concentration of palmitate led to down regulation of C5 expression in goose primary hepatocytes whereas upregulation in mouse primary hepatocytes and HepG2 cells. In conclusion, regulation on C5 expression by fatty liver related factors including high level of palmitic acid may contribute to the protection of goose liver from severe hepatic steatosis.     

免疫剂量和母源抗体对禽流感重组鸡痘病毒活载体疫苗免疫效力的影响

利用表达 H 5亚型禽流感病毒 (AIV)血凝素基因的重组鸡痘病毒 (r FPV- HA)以不同剂量免疫 1日龄 SPF鸡、有或无母源抗体 (FPV、AIV H5)的商品鸡 ,并于免疫后 2 1d利用同亚型 AIV通过肌肉注射进行致死性攻击 ,通过检测免疫后 HI抗体应答、比较攻毒后发病率和死亡率评价免疫剂量和母源抗体对 r FPV- HA免疫效力的影响。结果发现 ,免疫后 2 1d,15 %～ 2 0 %的 SPF鸡和无母源抗体商品鸡可检出 HI抗体 ,而含母源抗体商品鸡检测不到 HI抗体。利用H5亚型 AIV致死性攻击后 ,10 3～ 10 6 PFU的 r FPV- HA可保护 95 %～ 10 0 %的 SPF鸡和无母源抗体商品鸡抵御强毒攻击 ,使之免于发病和死亡 ;而不同剂量 r FPV- HA接种的含母源抗体商品鸡有 80 %～ 90 %发病和死亡。结果表明 ,在较宽的免疫剂量范围内 ,r FPV- HA对 SPF鸡和无母源抗体商品鸡可提供良好的保护 ,显示出一定的应用前景 ;母源抗体影响 r FPV- HA诱导的免疫应答 ,且提高免疫剂量亦不能克服其干扰作用 ,这提示在实际应用中需优化免疫程序 ,避免母源抗体干扰。     

混凝土结构表面蜂窝麻面成因及其防治措施

随着建筑业的飞速发展和科技水平的不断提高,工程对混凝土的各种性能要求越来越高,不仅要求混凝土工作性能好、强度指标高、耐久性好等,而且还要求混凝土结构表面无蜂窝麻面光洁如镜的外观,尤其是清水混凝土结构要求更为严格,为此我们必须加以防范,给予重视。     

一种新型微生态保健品在兽医临床中的应用研究

利用一种微生态保健品和3种抗菌素药物，即氟哌酸、氯霉素、庆大霉素在兽医临床上用于治疗仔猪黄白痢，断奶猪的应激性腹泻，肥猪及母猪的腹泻作了对比试验，结果表明：微生态保健品对仔猪黄痢的治愈率为93％，对仔猪白痢的治愈率为95％，对断奶仔猪的应激性腹泻治愈率为94％，对肥猪及母猪的腹泻治愈率为100％。与氟哌酸、庆大霉素的疗效比较，差异显著（P＜0．05）；与氯霉素比较差异极显著（P＜0．01）．     

霉形体膜蛋白溶解及含量测定方法研究

本文选择双蒸水；０．１ｍｏｌ／ＬＮａＯＨ；１．０ｍｏｌ／ＬＮａＯＨ；４％ＤＯＣ和１％ＳＤＳ条件分别对猪肺炎霉形体膜制剂作增溶处理，使膜蛋白溶解，然后采用Ｌｏｗｒｙ法进行蛋白质含量的测定．测定结果表明：０．１ｍｏｌ／ＬＮａＯＨ溶解效果较好，所测得膜蛋白含量达６８．８％左右。，数据更为接近实际含量．     

国内雏鸭病毒性肝炎的研究进展

本文就国内雏鸭病毒性肝炎的病原特性、疾病诊断和防制等做一简要综述并提出了该病今后的研究方向。     

继电保护用电流互感器的暂态特性数字仿真及电磁优化设计

本文在分析CT的暂态特性及其动态磁化过程的基础上,建立了计及铁芯饱和、局部磁滞回环、动态剩磁影响的CT单、复励磁暂态过程数字仿真模型,提出了继电保护用P、TPX、TPY、TPz级CT的电磁优化设计方法,编制了计算机程序,用于CT的电磁优化设计及数字仿真分析.     

催干剂对氨基环氧树脂阴极电泳漆的影响

以氨基环氧树脂为基体树脂，Co^2 ,Pb^2 盐为催干剂合成了阴极电泳漆，并对膜性能进行考察，结果表明，所合成的阴极电泳涂料在PH值为6－7、电泳时间2min的条件下。加入不同的催干剂，在不同的烘干温度下，得到性能不同的漆膜。经过膝膜综合性能试验，结果表明，加入钴和铅复合催化剂，在160℃左右烘干20min，可得到完全固化，硬度较高、耐潮、耐盐、耐酸碱性较好的漆膜。