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.     

山东小麦玉米机械化种植模式

通过调研山东75家新型农业经营组织生产情况，分析规模生产条件下山东小麦玉米种植规格、各环节作业方式和机械配备等生产现状与存在问题，提出了一种适合规模化生产的小麦玉米机械化种植模式，并对各环节作业提出了技术要求。      

Effect of chlorogenic acid on intestinal inflammation,antioxidant status,and microbial community of young hens challenged with acute heat stress

Heat stress in poultry is deleterious to productive performance. Chlorogenic acid (CGA) exerts antibacterial, anti-inflammatory, and antioxidant properties. This study was conducted to evaluate the effects of dietary supplemental CGA on the intestinal health and cecal microbiota composition of young hens challenged with acute heat stress. 100-day-old Hy-line brown pullets were randomly divided into four groups. The control group (C) and heat stress group (HS) received a basal diet. HS + CGA₃₀₀ group and HS + CGA₆₀₀ group received a basal diet supplemented with 300- and 600-mg/kg CGA, respectively, for 2 weeks before heat stress exposure. Pullets of HS, HS + CGA₃₀₀, and HS + CGA₆₀₀ group were exposed to 38°C for 4 h while the control group was maintained at 25°C. In this study, dietary CGA supplementation had effect on mitigate the decreased T-AOC and T-SOD activities and the increasing of IL-1β and TNFα induced by acute heat stress. Dietary supplementation with 600 mg/kg CGA had better effect on increasing the relative abundance of beneficial bacterial genera, such as Rikenellaceae RC9_gut_group, Ruminococcaceae UCG-005, and Christensenellaceae R-7_group, and deceasing bacteria genera involved in inflammation, such as Sutterella species. Therefore, CGA can ameliorate acute heat stress damage through suppressing inflammation and improved antioxidant capacity and cecal microbiota composition.     

金华市农业机械化投入机制初探

农业机械化是农业现代化的基础，是现代化的先决条件，发展农业机械化迫切需要加大投入。为此，分析了金华市现阶段农机化投入的现状及存在的问题；提出了通过建立政府、集体、信贷、农户、外资等“多位一体”的投入机制，加大农机化投入，促进农机化事业健康发展的思路。     

比格犬人工感染埃立克体病的临床研究

为了表述比格犬感染埃立克体（Ehrlichia)后的临床表现，用已确证为Ｅ．platys和Ｅ．canis混合感染的犬血对５条比格犬进行了人工感染，并对临床和血液学变化进行了观察。埃立克体病的潜伏期为６－２９天，其后的临床表现为急性发热、眼结膜苍白、厌食、精神沉郁、体重严重减轻、腹泻带血、多处有淤血斑点出现、６－４５天内全部死亡。血液学变化显示血红蛋白和白细胞明显减少（Ｐ＜０．０１，Ｐ＜０．０５）。由此可见，比格犬对２种埃立克体（Ｅ.canis和Ｅ．platys）混合感染的性很高，严重的临床表现与美国学者普遍认为的亚临床状态相左，这可能是中国Ｇzh981株（Ｅ．platys)和Ｇzh982株（Ｅ．casnis)与国外株在毒力上的差异所致。     

电子时代的医学图书馆馆员和循证医学

 

简要阐述了循证医学的概念及其基本特点，探讨了电子时代循证医学对于医学图书馆员的要

求，同时提出了电子时代医学图书馆员应该具备的知识和技能。

     

徐光启的水利思想

明末著名的政治家、科学家徐光启十分重视我国的水利事业，积极钻研水利科技。文章从主导观点、地区治水、水利科技、水资源利用等多方面探讨他的丰富水利思想，这些思想至今仍具有现实意义。     

沼肥对苹果生物性状的试验初报

笔者对苹果施用沼肥后的生物性状进行了长达4a的对比试验研究，采取对比设计法，在叶、枝、花、果等器官的相关指标取得了极为明显的效果，在果业生产上有极好的推广价值。     

优质高产紫花苜蓿新品种CW 400

CW 400系宁夏固原市农科所2000年从美国西海岸种子公司引入,通过多年多点试验、鉴定,2006年经宁夏回族自治区农作物品种审定委员会审定推广,适宜干旱半干旱地区种植.     

百脉根单株产量主要农艺性状的相关和通径分析

通过对百脉根单株的11个农艺性状的相关分析,结果表明:分枝长度(X2)、分枝节间数(X3)、分枝茎粗(X4)、侧枝数(X6)、侧枝长度(X7)、侧枝节间数(X8)、侧枝茎粗(X9)对单株产量(Y)的作用达到极显著水平,分枝数(X1)、自然高度(X11)与单株产量的相关性达到显著水平,而分枝叶柄长度(X5)、侧枝叶柄长度(X10)则与产量的相关性不显著.通径分析结果表明:各性状对产量的直接效应从大到小依次为:分枝长度(1.121 6)>分枝节间数(0.346 3)>侧枝长度(0.114 6)>分枝数(0.106 4)>分枝茎粗(0.084 6)>侧枝节间数(0.034 2)>侧枝茎粗(0.028 9)>侧枝数(0.021 6)>侧枝叶柄长度(-0.043 6)>分枝叶柄长度(-0.065 4)>自然高度(-0.748 2).