Identification of differentially expressed genes associated with bud dormancy release in tree peony （Paeonia suffruticosa） by suppression subtractive hybridization

A subtractive cDNA library was developed to study genes associated with bud dormancy release in tree peonies.In order to identify genes that are highly expressed in buds released from dormancy,588 clones were examined by differential screening.Of these,185 clones were selected to be sequenced.A total of 37 unique sequences were obtained of which only 31 sequences have matches in the NCBI database or the Arabidopsis thaliana protein database.Semi-quantitative RT-PCR was used to confirm further the expression...     

大熊猫IL-4基因的克隆与序列分析

应用RT-PCR技术从ConA诱导培养的大熊猫外周血淋巴细胞总RNA中扩增得到大熊猫IL-4基因,并将其克隆到PGEM-T载体中。经菌落PCR鉴定、序列测定及序列分析,结果表明,克隆得到的IL-4基因开放阅读框由396个核苷酸组成,编码一个由132个氨基酸组成的多肽,包括编码24个氨基酸的信号肽和108个氨基酸的成熟肽。与GenBank中已登录的大熊猫IL-4（DQ166512）的核苷酸序列同源性分别为99.5%和100%;与其他哺乳动物如犬、猫、人、猪、牛、羊、马、兔、鼠等的IL-4核苷酸同源性为50.7%（鼠）～87.7%（犬）;IL-4编码氨基酸同源性在35.7%（鼠）～78.8%（犬）;进化树构建结果表明,大熊猫与犬、猫遗传距离最近。     

机械CAD技术的发展

计算机辅助设计(CAD)技术的发展,从根本上改变了机械设计自动化的研究方向,大大提高了机械设计的质量和效率,缩短了产品更新换代的周期,在机械设计领域正在引起深刻的变革.     

N-氨甲酰谷氨酸对奶牛超排效果及血液指标的影响

本研究旨在探讨饲喂N-氨甲酰谷氨酸（NCG）对奶牛超数排卵效果及血液生化指标的影响。选取荷斯坦育成牛16头，随机分为2组，每组8头，对照组饲喂基础饲粮，试验组在基础饲粮的基础上饲喂20 g/（d·头）的NCG，采用连续4 d递减注射FSH法测定NCG饲喂时间对供体牛超排效果的影响，分别在3次超排处理的第0、5、9天采集尾根静脉血测定激素指标及血清生化指标。结果表明，①NCG饲喂20 d时（第1次超排），试验组头均回收胚数、可用胚数、退化胚数、未受精卵数与对照组相比差异均不显著（P>0.05）；NCG饲喂50 d时（第2次超排），试验组头均回收胚数显著高于对照组（P<0.05）；NCG饲喂80 d时（第3次超排），试验组头均可用胚数显著高于对照组（P<0.05）；综合考虑3次超排效果，试验组头均回收胚数显著高于对照组（P<0.05）。②NCG饲喂时间对供体牛血清中促卵泡素、促黄体素、孕酮、雌二醇的浓度均无显著影响（P>0.05），说明NCG饲喂时间对奶牛生殖激素的分泌无影响或为次要影响因素，超排效果的变化与生殖激素变化无明显的关联作用。③NCG饲喂时间对供体牛血清中谷草转氨酶的浓度无显著影响（P>0.05）；在NCG饲喂13 d时，试验组供体牛血清中葡萄糖浓度显著高于对照组（P<0.05）；在NCG饲喂34 d时，试验组供体牛血清中尿素氮浓度显著低于对照组（P<0.05）；在NCG饲喂43和69 d时，试验组供体牛血清中一氧化氮浓度显著高于对照组（P<0.05）。综合考虑，在重复3次超排时，每头供体牛每天饲喂20 g NCG，可提高3次连续超排的回收胚数4.98枚及可用胚数1.8枚，进而降低胚胎的生产成本。     

淀粉水解酶及其水解产物的研究进展

综述了淀粉水解酶的种类和特点,以及不同淀粉酶的酶解产物,并重点介绍了这些产品的主要功能和特性。     

公益性数字文化体系建设问题研析

公益性数字文化是一种新型文化模式,是文化创新的重大举措,它的发展必然会面临新的问题。论文通过研究,探讨公益性数字文化建设中面临的问题,从资源、技术、服务、管理等方面给出建设性意见,并提出解决问题的办法。     

Effects of Inhibition of Different Rumen Microbial Activity on Rumen Fermentation and Fatty Acid Metabolism in Buffaloes

This study was aimed to evaluate the effects of inhibiting rumen bacteria,fungi and protozoa with adding linoleic acid and linolenic acid on in vitro rumen fermentation and fatty acid metabolism in buffaloes.Both fatty acids were supplemented with substrate and roughage (3:7) at the rate of 3% on dry matter (DM) basis in an in vitro batch culture system,there were 5 repetitions for each group.At the same time,four groups were set up:Control group and inhibition groups of protozoa,bacteria and fungi.After 24 h of incubation,total gas production,CH₄,pH,VFA,NH₃-N,MCP and LFA concentrations were measured.The results showed that:①With the addition of linolenic acid,compared with control group,the gas production decreased significantly after inhibition the growth of bacteria and protozoa,CH₄ production increased significantly after inhibition of the growth bacteria and fungi,and CH₄ production decreased significantly after inhibition of the growth protozoa (P<0.05).With the addition of linoleic acid,compared with control group,the gas production decreased significantly after inhibiting the growth of bacteria,fungi or protozoa,and CH₄ production was significantly lower than other groups after inhibition of protozoa (P<0.05).② After inhibiting the growth of bacteria,fungi or protozoa,the pH and MCP concentration were affected significantly with the addition of linolenic acid (P<0.05),there was no significant effect on NH₃-N concentration with the addition of linoleic acid (P>0.05).③ Compared with control group,the content of acetic acid and propionic acid was reduced significantly after inhibiting the growth of bacteria,fungi or protozoa (P<0.05).The butyric acid was reduced significantly after inhibiting the growth of bacteria with the addition of linolenic acid (P<0.05).The butyric acid was reduced significantly after inhibiting the growth of bacteria,fungi or protozoa with the addition of linoleic acid (P<0.05).④ Compared with control group, the concentrations of C11:0, C12:0, C13:0, C14:0, C14:1n5, C15:1n5, C16:1n7, C16:0, C18:3n3, C18:2n6c, C18:0, C20:2n6, C20:3n6, C20:1, C20:3n3, C20:0, C21:0, C22:6n3, C22:2n6, C22:0 was reduced significantly after inhibiting the growth of bacteria with the addition of linolenic acid, the concentrations of C12:0, C13:0, C14:0, C15:0, C16:1n7, C16:0, C17:0, C18:3n6, C18:3n3, C18:2n6c, C18:1n9t, C18:0, C18:2(cis-9,trans-11), C18:2(trans-10,cis-12), C20:2n6, C20:1, C20:0, C21:0, C22:6n3, C22:0, C23:0, C24:1n9, C24:0 was reduced significantly after inhibiting the growth of bacteria with the addition of linoleic acid (P<0.05).The results revealed that the addition of linoleic acid and linolenic acid could significantly manipulate in vitro rumen fermentation parameters,CH₄ yield and fatty acid composition after inhibiting the growth of bacteria,fungi or protozoa.Protozoa greatly contributed to total gas and CH₄ production while bacteria significantly affected rumen fatty acid metabolism.     

新中国农业科技60年

新中国成立60年,特别是改革开放以来,我国农业科技有了长足的发展。文章系统回顾了新中国农业科技60年来党中央、国务院对农业科技工作的重要部署,农业科研机构的六大战略重点,我国农业科技事业取得的重要成就,以及农业科研事业在科研机构发展壮大、专业队伍粗具规模、试验研究条件不断改善、国际合作与交流日趋扩大等方面的长足发展,最后详细论述了科技进步和创新对我国农业和农村经济发展的重大贡献。我国以不到世界10%的耕地,养活了世界20%的人口,创造了世界农业发展史上的奇迹,也为世界粮食安全作出了重大贡献。     

克氏原螯虾温室大棚规模化繁育技术及工艺

阐述了克氏原螯虾温室大棚规模化繁育技术,包括繁育设施的建造、工厂化人工诱导繁殖,规模化网箱育苗技术等,为克氏原螯虾育苗生产提供借鉴.     

均匀设计优化香草兰中香兰素的超临界萃取工艺

研究超临界Co2萃取香草兰豆荚中香兰素等香料成分的工艺,以香兰索产量为检测指标,使用均匀设计-偏最小二乘法回归分析,优化萃取工艺的压力、温度、时间和夹带剂乙醇的体积4个因子,确定最佳提取工艺条件为:压力41.10 MPa,温度50℃,时间180 min,夹带剂体积5.0 mL,此时,20g香草兰原料萃取香兰素的理论产量为177.211 mg.对该技术应用于香草兰中香兰素提取产业化的前景和可行性进行分析探讨.