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。     

保定市工业废水农灌的研究

本文论述了保定市工业废水经农灌土地处理,对土壤、地下水和农作物品质的影响。结果表明:以造纸、食品、轻纺和化工为主的工业废水在重金属常年不超出农灌标准下,宜于在非盐化土壤灌溉;废水中硫化物超标,通过土壤生物区系,能降低毒性;废水中常规有机物,农灌后利大于害;只要在土壤容量允许内,可具有二级污水处理工艺不能完成的效果。     

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.     

农用地因素法与样地法分等对比研究——以重庆市丰都县为例

对现行《农用地分等规程》中因素法和样地法进行探讨，寻求农用地分等的最佳方法。文献资料法、比较分析法。《规程》中因素法分等使得研究区单元分值出现拐点，划分等别部分与实际不符；样地法分等结果则不存在这一问题。在农用地分等中，在县域内种植制度为一年两熟和一年一熟的地区采用样地法分等更合理。     

新疆盐碱地种植耐盐小麦土壤盐分的变化

新疆干旱区有大量盐碱地 ,很大程度上限制农业的可持续发展。盐碱的利用改良和水资源的高效利用的研究 ,面临巨大的挑战。盐碱地上种植耐盐小麦既有生产效益 ,又有改良土壤盐渍化作用。在传统灌溉管理下 ,当土壤原始盐分 2 .0 %时 ,在壤质土壤上种植耐盐小麦 1— 2年 0— 40cm土层盐分可降到 0 .8%。在粘壤土、壤土土质的土壤中 ,种植耐盐小麦 5年时 ,0— 1 0 0cm土层盐分可降到 0 .5 % ;种植 7年后 ,0— 1 0 0cm土层盐分降到 0 .2 %左右 ,且在以后种植条件下 ,土壤盐分趋于平衡状态 ,变化很小。种植耐盐小麦引起的盐分变化 ,灌溉水为主要作用 ,以至经多年种植 ,土壤表现为脱盐碱化现象。     

土壤中根皮苷和根皮素对桃幼苗的影响

以一年生桃嫁接苗为试材,在盆栽条件下研究了苹果园土壤中特征酚酸类物质——根皮苷和根皮素对桃苗生物量、根系活力、根系保护性酶活性和MDA含量的影响。结果表明,根皮苷对桃幼苗的伤害显著,与对照相比,鲜质量、干质量分别降低了16.66%和21.58%,根系活力降低了33.04%,SOD、POD活性分别降低了40.80%和31.10%,MDA含量提高了116.34%。根皮素对桃苗的影响不大。高锰酸钾处理明显缓解了根皮苷对桃苗的伤害,苹果园土壤中的根皮苷含量降低了57.80%,提高了桃苗的生物量、根系活力和保护性酶活性,降低了MDA含量。综上,老龄苹果园土壤实测含量的根皮苷(0.343mg·kg~(-1))可降低桃苗的生物量,适量的高锰酸钾能缓解根皮苷的伤害作用。     

帽儿山地区脂松种源试验林生长指标分析

引进优良的外来树种可以丰富本国或本地区林业建设的树种资源,增加木材产量和林产品的种类。通过对引进的美国东部7个脂松种源进行试验,得出更适宜栽植区的种源。在树高方面,较好的4个种源依次为MIDC(Dickenson County,Michigan)、MNCNF(Chippewa National Forest,Minnesota)、MIMC(Manistee County,Michigan)和WIOC(Oneida County,Wisconsin);2004年高生长较好的4个种源依次为WIOC、MIDC、MIMC和MNCNF;2005年高生长较好的4个种源依次为MIDC、MIMC、MNCNF和WIOC;地径较好的4个种源依次为MIDC、WIOC、MIMC、MNCNF。该4个种源间各项生长指标差异不显著;在保存率方面,7个种源间差异不明显。