青海湖中沙堤的形成及其对湖水位的影响

青海湖水位下降的因素很多,本文仅从青海湖区风沙、泥沙入湖后形成水下沙堤进而发展成子湖这方面,浅析对湖水位的影响。     

糖苷水解酶家族基因AghyGH1a参与莲草直胸跳甲对皂苷的代谢

为了解植物化合防御物质皂苷对专食性天敌莲草直胸跳甲Agasicles hygrophila的防御作用,测定莲草直胸跳甲2龄幼虫取食皂苷后的排泄和肠道变化,利用转录组测序筛选参与皂苷代谢的候选基因,并采用 RNA 干扰技术鉴定候选基因功能。结果发现,取食皂苷导致莲草直胸跳甲幼虫排泄量增加,肠道畸变,排泄量与取食皂苷浓度正相关。转录组测序发现,与对照相比,取食 100 mmol/L皂苷处理的莲草直胸跳甲幼虫肠道有496条差异表达基因,其中261个上调基因和235个下调基因。GO分类和KEGG分类分析发现糖苷水解酶家族1（glycoside hydrolase family1,GH1）基因集中在碳水化合物水解通路。利用RNA干扰技术鉴定发现,莲草直胸跳甲AghyGH1a基因沉默可导致幼虫取食皂苷后排泄量增加,肠道内容物颜色更暗沉。表明莲草直胸跳甲AghyGH1a参与皂苷代谢。     

代谢酶抑制剂PX对除草剂防除稗草的增效作用

为解决除草剂防除困难的问题,采用室内盆栽试验测定了PX、PM和Mn²⁺三种代谢酶抑制剂对精喹禾灵、莠去津、烟嘧磺隆、硝磺草酮和烯禾啶防除稗草Echinochloa crus-galli的增效作用,测定不同用量代谢酶抑制剂PX对这5种除草剂的增效作用及其与莠去津混用后稗草体内谷胱甘肽转移酶（glutathione S-transferase,GST）和细胞色素 P450（cytochrome P450,CYP450）活性的变化。结果显示,在3种代谢酶抑制剂中,代谢酶抑制剂PX对精喹禾灵、莠去津、烟嘧磺隆、硝磺草酮和烯禾啶5种除草剂的增效作用最显著。不同用量代谢酶抑制剂PX对不同除草剂的增效作用不同,其中75 g (a.i.)/hm²代谢酶抑制剂PX对莠去津的增效最佳,株防除效果和鲜重防除效果分别增加了35.33个百分点和37.33个百分点。莠去津与代谢酶抑制剂PX混用后,稗草体内GST和CYP450活性均较对照显著降低。表明除草剂与代谢酶抑制剂PX混用能增加除草剂对稗草的防除效果,可以达到减施除草剂的目的。     

草地贪夜蛾核型多角体病毒对草地贪夜蛾的毒力及其侵染特征

为明确草地贪夜蛾核型多角体病毒（Spodoptera frugiperda multiple nucleopolyhedrovirus,SfMNPV）对草地贪夜蛾Spodoptera frugiperda 的毒力及其体内外侵染特性,于室内测定SfMNPV对草地贪夜蛾的毒力,采用苏木精-伊红（hematoxylin-eosin,HE）染色分析SfMNPV侵染后草地贪夜蛾的组织病理学特征,通过实时荧光定量PCR（real-time fluorescence quantitative PCR,qPCR）技术分析SfMNPV在草地贪夜蛾体内和Sf9细胞系中的复制特征。结果表明,SfMNPV对草地贪夜蛾2龄幼虫的LC₅₀和LT₅₀分别为7.39×10⁵ OBs/mL和3.82 d;SfMNPV可侵染草地贪夜蛾幼虫的真皮、气管、脂肪体和中肠等组织,未侵染肌肉组织;SfMNPV侵染96 h后草地贪夜蛾体内SfMNPV基因组拷贝数最大,为3.91×10⁶ 拷贝数/ng,SfMNPV侵染96 h后Sf9细胞培养上清液中SfMNPV基因组拷贝数最大,为2.08×10⁷ 拷贝数/mL。     

Exploring the effectiveness of in ovo feeding of vitamin C based on the embryonic vitamin C synthesis and absorption in broiler chickensOA

Background: Many researches about in ovo feeding(IOF) of vitamin C(VC) are gradually carried out to explore physiological development in chicken, but little studies focus on VC synthesis capacity of the embryo itself, the selection of injection site and the effectiveness of IOF of VC. This study aims to explore the above problems.Results: Kidney and yolk sac were the main organs for VC synthesis and L-gulonolactone oxidase(GLO) expression was lower during pre-hatch development than that during p...     

Effects of exosomes derived from hypoxia-preconditioned umbilical cord mesenchymal stem cells on function of endothelial cells

AIM To investigate the effect of exosomes derived from hypoxia-preconditioned human umbilical cord mesenchymal stem cells (hUCMSCs) on proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs). METHODS hUCMSCs and HUVECs were isolated, cultured and identified. Exosomes derived from hUCMSCs were extracted by ultracentrifugation. The morphological change of exosomes was observed under transmission electron microscope. The particle size and concentration of exosomes were detected by nanoparticle tracking analysis, and the surface specific marker proteins of exosomes were determined by Western blot. hUCMSCs were divided into normoxia group and hypoxia group. The viability of hUCMSCs was measured by CCK-8 assay. HUVECs were divided into control group, normoxic exosome group and hypoxic exosome group. The proliferation of HUVECs was detected by EdU assay. The migration ability was detected by cell scratch assay and Transwell experiment. Tube formation ability was evaluated by tube formation experiment. RESULTS Compared with normoxia group, hypoxia pretreatment enhanced the viability and exosome release of hUCMSCs. Compared with normoxic exosome group, hypoxic exosomes enhanced the proliferation, migration and tube formation of HUVECs. CONCLUSION Exosomes derived from hUCMSCs under hypoxia enhances the proliferation, migration and tube formation of HUVECs.     

司帕沙星在雏鸡体内药代动力学及残留的研究

选用30日龄健康海兰鸡65只,按5mg／kg体重口服给予司帕沙星,定期采样,以高效液相色谱法测定血浆、肝、肾、心、肺和肌肉中司帕沙星的含量,研究司帕沙星在鸡体内的药动学与残留。结果表明:司帕沙星在血液中经时过程符合一级吸收二室开放模型,其主要动力学参数如下:t1／2α0.9585h,t1／2β11.7447h,tmax0,6514 h,Cmax0.5271 μg／ml,AUC1.7908mg／L／h。肾脏、心脏的药时数据符合一级吸收二项指数方程,其主要动力学参数分别为:t1/2Ka0.3733 h、0.1530h,t1／2k1.3007 h、2.1013h,tmax1.01420h、0.6239 h,Cmax2.1104μg／ml、1.6721 μg／ml,AUC6.51764 mg／L／h、6.2286mg／L／h。司帕沙星在肝脏、肺脏、肌肉中的经时过程符合一级吸收三项指数方程,主要动力学参数分别为t1/2α0.3672 h、0.6156 h、1.5835 h,t1/2β3.9998 h、15.0271 h、12.0103h,tmax0.7458 h、0.7322 h、1.3726 h,Cmax4.4709μg／ml、2.5267μg／ml、0.9760μg／ml,AUC20.893 mg／L／h,27.242 mg／L／h、9.7943mg/L/h。建议司帕沙星在鸡体内的休药期为7d。     

从动物源性食品安全存在的问题谈可追溯制度的建立与完善

食品安全,尤其是作为食品的重要组成部分的动物源性食品安全,直接关系着广大人民群众的身体健康和生命安全,关系着国民经济与社会     

兔健宝对感染球虫病家兔血液学值的影响

本试验探讨了兔健宝对人工感染球虫病家兔的部分血液学值的影响。结果表明：红细胞及白细胞总数、嗜中性白细胞分别于感染后５～２０天、１０～２５天及５～３０天显著低于对照组（Ｐ＜０．０５）;而淋巴细胞百分率和Ｔ细胞阳转率于感染后５～３０天、１０～３０天显著高于对照组（Ｐ＜０．０５）;嗜酸性白细胞、嗜碱性白细胞和单核细胞无明显差异。由此提示：兔健宝具有减轻家兔感染球虫后的肠道出血,调节机体非特异性免疫应答反应和提高机体特异性免疫应答的活性。     

高淀粉酿造高粱新品种晋粱 112 号的选育

晋粱 112 号是山西农业大学高粱研究所以河北承德市农林科学院（原河北承德地区农科所）引进的不育系承 16A为母本,以通过组培育种技术选育的优良恢复系 R111 为父本,在山西农业大学高粱研究所东白试验基地选育而成,2023 年通过农业农村部非主要农作物品种登记,登记编号为 GPD 高粱（2023）140102。2021-2022 年晋粱 112 号 2 年适应性试验平均产量达 9583.6kg/hm2,比对照晋杂 34 号平均增产 11.7% ;生育期 128.8d,幼苗绿色,芽鞘绿色,株高 169.7cm,穗长 30.9cm,穗纺锤形,中紧穗型,红壳褐粒,穗粒重 85.5g,千粒重 27.8g。该品种具有淀粉含量高、抗旱、抗丝黑穗病、丰产性好等优点,适宜在无霜期 130d 以上中晚熟地区（山西太原、晋中、长治,山东及新疆昌吉等）种植。