Mechanical properties of flax fibres treated by alkaline,enzyme and steam-heat     

Cao Yongjian  Chui YingHei  Chan Felisa  Gong Meng  Ren Haiqing  Wang Ge 《林业与环境科学》2018,(3)

In recent years there has been interest in using flax fibres to produce composites because of a number of attributes, including low density, biodegradability and high mechanical properties. It was found that treatment of flax fibres may be required to improve the bond quality with a resin. These treatments also have an impact on the properties of the fibres themselves. The objective of this project was to evaluate the impact of three treatment methods on the mechanical properties of flax fibres. The three treatment methods were alkaline, enzyme and steam-heat. After treatment, flax fibres were tested in tension using a universal test machine. Results showed that tensile strength and Young's modulus of flax fibre can be enhanced significantly by the three treatment methods, compared with untreated flax fibres. Enzyme treatment was shown to be the best approach to improve mechanical properties of flax fibre than alkaline and steam-heat treatment.  相似文献   

高置式大容量毒饵站对东北农田害鼠的防治效果初探   总被引：1，自引：0，他引：1  

丛林  罗婵  郭永旺  刘晓辉  王勇  王大伟 《植物保护》2018,44(1):190-193

毒饵站是化学防鼠常用设施,可以减少非靶标动物的误食风险。目前常用毒饵站容量小、毒饵易浪费、添加毒饵不便的缺点限制了其在东北地区的大规模应用。本研究针对东北农业环境特点,设计了一种新型高置式大容量毒饵站,在黑龙江了进行为期1年的防效试验,并测试其作用范围。结果表明,这种毒饵站每年毒饵用量2.8~3.8kg,鼠密度控制率可长期保持在75%以下;其有效覆盖面积为1.1hm2,最佳防治效果的覆盖面积为0.5hm2。这些结果说明这种大容量高置式毒饵站具有毒饵添加便捷、无浪费的优点,在东北地区防治经济效益远远大于其他传统小容量毒饵站,值得在当地应用和推广。  相似文献   

磁性分子印迹聚合物的制备及对食品中氯霉素残留的检测     

李增威  王娜  雷婵  曾月  付珍珍  何利  刘书亮  周康  敖晓琳  陈姝娟 《浙江农业学报》2018,30(6):1063

将磁性分离技术和表面分子印迹技术相结合,首先通过化学改性的方式在Fe₃O₄磁性纳米粒子表面接枝双键,以氯霉素(chloramphenicol,CAP)为模板分子、甲基丙烯酸(methacrylic acid,MAA)为功能单体、乙二醇二甲基丙烯酸酯(ethylene glycol dimethacrylate,EDGMA)为交联剂、偶氮二异丁腈(azobisisobutyronitrile,AIBN)为引发剂,采用悬浮聚合法合成CAP的磁性分子印迹聚合物微球(magnetic molecularly imprinted polymer,MMIP),以及对应的非印迹微球(magnetic molecularly non-imprinted polymer,MNIP)。在表征试验中,用傅里叶变换红外光谱仪对每一步合成的产物进行红外光谱检测,用扫描电子显微镜对MMIP和MNIP的微观形态进行观察,用振动磁强计测定磁性纳米粒子和MMIP的饱和磁强度。对MMIP和MNIP的吸附性能进行研究,将MMIP作为固相萃取剂应用于实际样品检测,进行方法学考查。试验结果表明,合成的磁性分子印迹聚合物微球直径400~700 nm,分散性较好,在溶剂中可在外加磁场作用下快速分离。MMIP的最大表观吸附容量可达29.18 mg·g^-1,具有良好的选择识别性能。MMIP作为固相萃取剂在对实际样品进行检测时回收率(86.30%~94.21%)、精密度(RSD≤1.53%)、稳定性(RSD≤1.87%)均良好,且具有较低的检测限(3.0 μg·kg^-1)。将MMIP作为固相萃取剂用于食品中残留氯霉素的分离检测具有良好的效果。  相似文献   

15N-labelled fertiliser recovery by maize (Zea mays L.) and leaching of nutrients as influenced by oil palm empty fruit bunch biochar in a mini-lysimeter under controlled tropical environment     

Sherwin Chan Kit Lee  Abu Bakar Rosenani  Che Fauziah Ishak  Azni Idris  Khairuddin Abdul Rahim  Andreas Meyer-Aurich 《Archives of Agronomy and Soil Science》2017,63(12):1711-1724

Converting oil palm empty fruit bunches into biochar is an alternative waste management method and has strong potential to improve N fertiliser use efficiency in agriculture. The aim of this study was to determine the effectiveness of oil palm empty fruit bunch biochar (EFBB) in improving recovery of ¹⁵N-labelled nitrogen fertiliser by maize (Zea mays L.) and leaching of mineral N and K. An experiment was conducted in a mini-lysimeter system with randomised complete block design layout and six replications under controlled environment in a rain shelter. Each mini-lysimeter was filled with 20 kg of sandy loam soil before adding EFBB (0, 5, 10 and 20 Mg ha^?1). The N source used was (¹⁵NH₄)₂SO₄ at 80 kg N ha^?1 (2 at% ¹⁵N excess). Maize was irrigated to induce leaching every 4 days. Maize plant and soils were sampled 58 days after sowing (tasselling stage). Application of EFBB significantly reduced cumulative leachate volume and mineral N leaching. Soils applied with EFBB significantly improved ¹⁵N fertiliser recovery in maize and dry matter weight. This study shows that EFBB has the potential to be applied on highly weathered acidic soil as an amendment to improve fertiliser efficiency and crop growth.  相似文献   

新城疫病毒LaSotaC5株感染性克隆的构建及病毒拯救     

汪军卿  张向乐  孟春春  仇旭升  孙英杰  谭磊  宋翠萍  丁铲 《中国动物传染病学报》2013,(6):1-7

将本实验室保存的一株LaSota病毒用有限稀释法接种鸡胚进行纯化,连续传代5次后筛选到1株高血凝效价的纯培养克隆株,命名为LaSotaC5,并对其进行全基因组测序,克隆株与亲本株在生物学特性与基因序列上都存在一定的差异。参照LaSotaC5株全基因序列单酶切位点,用RT-PCR的方法将基因组分8段扩增,按照病毒基因组的结构顺序,将克隆片段定向插入到TVT转录载体中,成功构建含有病毒全长eDNA的转录载体TVT．LaSotaC5。将TVT-LaSotaC5与辅助质粒pCI-NP、pCI-P和pCI—L共转染BSR—T7／5细胞,成功拯救出了具有感染性的LaSota株新城疫病毒。病毒的成功拯救为后续基因功能和疫苗载体开发等方面的研究提供了平台。  相似文献   

常见耐药基因多重PCR方法的建立及用于禽致病性大肠杆菌耐药性监测     

张耀东  朱红  AFAYIBO Doss&#  h Jean Ap&#  tre  王瑶  易正飞  信素华  陶程琳  李涛  祁晶晶  田明星  丁铲  于圣青  王少辉 《畜牧兽医学报》2020,51(12):3193-3198

本研究旨在建立β-内酰胺类、四环素类、氨基苷类、酰胺醇类、磺胺类抗菌药物耐药基因的多重PCR检测方法,用于耐药基因的快速检测。根据GenBank公布的上述5类抗菌药物的耐药基因序列,设计17对特异性引物。通过优化PCR体系和反应程序,建立4组耐药基因（cat+floR+tetB+tetC;dfrA12+sul2+sul1+bla_CTX-M+bal_TEM-1;aac3+aph3+aadA1+strB;tetA+cmlA+strA+sul3）的多重PCR反应体系。然后,检测多重PCR方法的特异性和敏感性。利用建立的多重PCR方法检测42株禽致病性大肠杆菌的耐药基因,同时,检测其耐药性,比较分析耐药基因和耐药表型之间的相关性。结果显示,建立的4组多重PCR体系可有效扩增出17个耐药基因片段,测序结果表明特异性较好。敏感性结果表明,4组多重PCR体系的菌液敏感性分别为10³、10⁴、10⁴和10⁵CFU。禽致病性大肠杆菌分离株的耐药基因多重PCR和单重PCR检测结果一致,其携带的耐药基因和耐药表型的符合率为92.86%。本研究建立的耐药基因多重PCR方法能简便、快速地检测常见的耐药基因,可用于耐药基因的传播、流行调查。  相似文献   

ZB transposon and chicken vasa homologue (Cvh) promoter interact to increase transfection efficiency of primordial germ cells in vivo     

S. Wang  Y. Wang  D. Shen  L. Zhang  W. Chen  S. Chan 《British poultry science》2019,60(6):724-728

ABSTRACT

1. In order to increase the efficiency of generating transgenic chicken, this trial focused on two points: primordial germ cells (PGCs）transfection in vivo and a germline-specific promoter.

2. In order to transfect PGCs in vivo, two plasmids (pZB-CAG-GFP, pCMV-ZB）were co-injected into chicken embryos via the subgerminal cavity at Hamburger and Hamilton (HH) stage 2–3 or via blood vessel at HH stage 13–14. Results showed that the percentage of GFP+ embryos, viability and hatching rate of embryos injected at HH stage 13–14 were significantly higher than that at HH stage 2–3.

3. Two plasmid transposon systems were used for chicken embryo micro-injections. The donor plasmid, with a green fluorescent protein (GFP) reporter gene, was mediated by the ZB transposon. The helper plasmid was a transposase expression vector driven by the promoter of the chicken vasa homologue (Cvh) gene or Human cytomegalovirus (CMV) promoter. Results showed that 60.98% of gonads in Cvh group expressed GFP, which was 52.50% higher than seen in the CMV group. Only gonad tissue from the Cvh group showed any GFP signal, whereas both gonads and other tissues in the CMV group showed green fluorescence.

4. The data suggested that ZB transposon-mediated gene transfer was efficient for transfecting PGCs in vivo; the Cvh promoter drove the transposase gene specifically in the germline and increased the efficiency of germline transmission. Blood vessels injection at HH stage 13–14 may be a more efficient route for PGCs transfection in vivo.  相似文献   

鸭疫里默氏杆菌血凝素基因的克隆、表达及其蛋白的定位分析     

屠晶  胡青海  于圣青  丁铲  韩先干  朱寅玉  王小兰  苗双  卢凤英 《中国预防兽医学报》2012,34(9):692-696

为研究鸭疫里默氏杆菌(R.anatipestifer)血凝素蛋白的功能,本实验克隆表达了鸭疫里默氏杆菌血凝素基因,并对其蛋白定位进行了分析。根据鸭疫里默氏杆菌CH3株血凝素基因序列设计一对特异性引物,采用PCR扩增不同血清型鸭疫里默氏杆菌的血凝素基因,进行序列测定与分析。结果表明其血凝素基因全长1 059 bp,编码352个氨基酸。不同血清型鸭疫里默氏杆菌血凝素间的氨基酸同源性为94.1%～100%,与黄杆菌3519-10株血凝素的氨基酸同源性为68.0%～68.9%。采用表达的血凝素蛋白免疫鼠血清和鸭抗鸭疫里默氏杆菌阳性血清对血凝素在细菌中的定位分析表明,鸭疫里默氏杆菌血凝素可能不是一种膜蛋白,而是存在于胞浆中的一种蛋白。  相似文献   

兽医公共卫生的概念和意义     

丁铲 《中国家禽》2008,30(11):30

1 兽医公共卫生和兽医公共卫生学 1999年,世界卫生组织定义兽医公共卫生是通过探索和应用兽医科学知识和技能为人类身心健康和社会福利服务的所有活动.  相似文献   

禽网状内皮组织增生症病毒p30蛋白的表达及检测     

张石磊  于圣青  陈鸿军  丁铲 《中国兽医寄生虫病》2011,19(6):15-19

根据禽网状内皮组织增生症病毒SNV株的前病毒基因组cDNA序列设计并合成1对引物,以pPB101质粒为模板,通过PCR扩增获得该病毒p30基因片段。将PCR产物克隆入表达载体pCold-HF中,构建的原核表达质粒pCold-p30转化BL21（DE3）菌,经IPTG诱导,p30蛋白呈现可溶性表达。用表达产物免疫6周龄BALB/c小鼠,制备p30抗体,经Westernblot和间接免疫荧光法检测,结果发现,原核表达的SNV株p30蛋白具有良好的免疫原性。  相似文献