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禽用核酸疫苗的研究进展 总被引:4,自引:0,他引:4
核酸疫苗是近 2 0年来发展起来的一种新型疫苗 ,它应用现代生物工程技术和分子生物学技术 ,克服了传统疫苗所存在的一些问题 ,具有传统疫苗不可比拟的优点 ,成为国内外学者争相研究的热点之一 ,呈现出良好的发展势头和应用前景。在禽病学领域 ,禽流感、新城疫、传染性支气管炎、传染性法氏囊等疾病的核酸疫苗得到了较为深入的研究 ,为禽用核酸疫苗乃至其他领域的核酸疫苗的进一步研究提供了有益的参考 ,也将会为养禽业带来不可估量的经济效益。通过对禽用核酸疫苗研究概况的综述 ,不仅可以了解国内外研究动态 ,借鉴最新的研究方法和研究思路 ,也可以发现问题和提出问题 ,进而寻求新的研究方向 相似文献
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核酸疫苗是近年来发展起来的一种新型疫苗,它应用现代生物工程和分子生物学技术,克服传统疫苗存在的问题,具有传统疫苗不可比拟的优点,呈现出良好的发展势头和应用前景。在兽用领域中,新城疫、禽流感、传染性支气管炎、传染性法氏囊炎等疾病的核酸疫苗得到了较为深入的研究,为兽用核酸疫苗乃至其他领域核酸疫苗的进一步研究提供了有益的参考。 相似文献
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近15年来,国内外在核酸疫苗研究及应用上取得了长足的进展。分别从基因治疗与核酸疫苗,核酸疫苗的免疫方法,免疫应答机理,增强核酸疫苗效力的途径以及核酸疫苗的优点和安全性等多个方面进行了综述。 相似文献
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日本血吸虫病核酸疫苗的研究 总被引:5,自引:0,他引:5
核酸疫苗能同时诱发体液免疫和细胞免疫 ,具有众多传统疫苗无法比拟的优点 ,并且佐剂的应用能增强核酸疫苗的免疫效果。抗日本血吸虫核酸疫苗的研究在实验动物和牛、羊等大家畜上取得一定进展 ,混和或多价疫苗是未来核酸疫苗的发展方向 相似文献
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The aim of this study was to develop a new genetic evaluation model to estimate the genetic merit of boars for growth based on 1) performance of their crossbred progeny fattened in the test station and 2) their own performance or those of relatives from the on-farm testing system. The model was a bivariate random regression animal model with linear splines and was applied to Piétrain boars from the Walloon Region of Belgium mated with Landrace sows. Data contained 1) 12,610 BW records from the test station collected on 1,435 crossbred pigs from Piétrain boars and Landrace sows, and 2) 52,993 BW records from the on-farm testing system collected on 50,670 pigs with a breed composition of at least 40% Piétrain or Landrace. Since 2007, 56 Piétrain boars have been tested in the station. Data used to estimate variance components and breeding values were standardized for the age to take into account heterogeneity of variances and then pre-adjusted at 210 d of age to put all records on the same scale. Body weight records from the test station and from the on-farm testing system were considered as 2 different traits. The heterosis effect was modeled as fixed regression on the heterozygosity coefficient. As all test station animals were similarly crossbred, smaller variation in heterozygosity caused the sampling error of the regression estimate at 210 d to be larger in the test station than in on-farm data with estimates of 28.35 ± 14.55 kg and 9.02 ± 0.67 kg, respectively. Therefore, the most likely reason for the large differences in estimates was sampling. Heritability estimates ranged from 0.37 to 0.60 at 210 and 75 d, respectively, for test station BW and from 0.42 to 0.60 at 210 d and 175 d, respectively, for on-farm BW. Genetic correlation decreased when the age interval between records increased, and were greater between ages for test station than for on-farm data. Genetic correlations between test station and on-farm BW at the same age were high: 0.90 at 175 d and 0.85 at 210 d. For the 56 boars tested in the station, the average reliability of their EBV for ADG between 100 and 210 d was improved from 0.60 using only test station data to 0.69 using jointly test station and on-farm data. Based on these results, the new model developed was considered as a good method of detection of differences in growth potential of Piétrain boars based on test station and on-farm data. 相似文献
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Roger Marchant 《New Zealand veterinary journal》2013,61(12)
Extract The 1985 edition of the Guide to Professional Conduct for veterinarians in New Zealand is about to be released. Changing demands of society, and of the profession itself, mean that any document which attempts to give guidance on matters of conduct must be continually reviewed or become irrelevant. Thus a new edition of the Guide has been produced some five years after the last edition. 相似文献
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青藏高原高寒草甸生态系统土壤有机碳动态模拟研究 总被引:12,自引:5,他引:7
利用高寒草甸区植被、土壤和气候等资料,借助Century模型研究了青藏高原高寒草甸生态系统土壤有机碳的动态。以2003年7月-2005年7月逐月气象观测资料为输入变量,模拟了自然条件下高寒矮嵩草草甸0~20cm 土壤微生物呼吸CO2-C 通量季节变化。模拟值与观测值进行的回归分析显示,二者具有较好的一致性(R2=0.89,P<0.05)。土壤有机碳动态模拟表明:1)自然条件下高寒草甸土壤有机碳在经历了一个快速积累过程后,积累速率逐渐趋于缓和,最终达到并接近稳定状态。稳定状态下0~20cm 土壤总有机碳库约7597.50~7694.10gC/m2。其中活性、缓性和惰性土壤有机碳组分占土壤总有机碳储量的2.80%,58.50% 和38.70%。2)过去45年(1960-2005)高寒草甸土壤有机碳呈振幅较为稳定的波动变化,但这种变化主要是土壤有机碳各组分波动变化的结果。气候波动对土壤有机碳影响主要与温度变化引起的惰性土壤有机碳库的变化有关,二者呈显著负相关(r=-0.548,P<0.01)。降水量对土壤有机碳及有机碳各组分的影响不显著。 相似文献
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汪阳生 《四川畜牧兽医学院学报》2009,(6):148-151
新一轮课程改革给农村基础教育带来了新的变化,赋予了新的内涵,注入了新的活力,深刻影响着农村基础教育的实施。但是轰轰烈烈的新课改在实施过程中也存在着很多问题:思想观念陈旧、教师编制紧缺、师资队伍整体素质低下、经费投入不足、教学资源缺乏、评价机制滞后等。文中针对这些问题提出了一些具体的解决办法:整顿与优化教师队伍建设;农村中小学校的管理应以人为本,突出人性化管理;进一步加大农村义务教育的经费投入;争取多方支持,建立由学校、家庭、社会三结合的教育沟通平台体系;构建新的评价机制,从单一的评价模式向多元化的评价模式转变等。 相似文献
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ZHANG Meng-hua CHEN Gang-liang ZANG Chang-jiang DONG Jing HUANG Xi-xia LU Dong-lin 《中国畜牧兽医》2016,43(10):2628-2633
This study was aimed to systematically analyze the difference of camel milk physicochemical index of different seasons,stage of lactation,production sites and milk station.Collected 18 372 testing data about raw camel milk quality which were purchased by a company in 2015.The range of each index was determined by the four point test method,SAS 8.1 least squares analysis of variance were performed on the processed data.The results showed that different area,milk stations,stage of lactation and season effect of camel milk had extremely significant influence (P<0.01) on the relative density,fat,non fat milk solid,milk protein,lactose,freezing point and ash.Therefore,the reproduction and childbirth of Bactrian camel had strong periodicity and seasonality,lead to a larger difference in camel milk yield and physicochemical index of different seasons and months within a year,at the same time,camel milk producers could learn about the quality of camel milk situation of different production sites,milk station,stage of lactation and season using such analysis methods,the quality of camel milk product was determines by the physical and chemical indicators and health conditions of the raw camel milk. 相似文献
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Prevention of leucaena toxicosis of cattle in Florida by ruminal inoculation with 3-hydroxy-4-(1H)-pyridone-degrading bacteria 总被引:2,自引:0,他引:2
A C Hammond M J Allison M J Williams G M Prine D B Bates 《American journal of veterinary research》1989,50(12):2176-2180
Ruminal microorganisms in cattle at a Florida agriculture research station did not have the ability to detoxify leucaena by degradation of 3-hydroxy-4(1H)-pyridone (3,4,-DHP), but a DHP isomer (2,3-DHP) was degraded in some cattle. Cattle with microorganisms that degraded 2,3-DHP were mostly Senepol cattle imported from St. Croix, US Virgin Islands, where leucaena is an indigenous species. Hereford cattle at the research station in Florida generally did not degrade 3,4-DHP or 2,3-DHP. An experiment was conducted in which a pure culture of 3,4-DHP-degrading bacteria was inoculated into Hereford cattle (with ruminal fistula) grazing leucaena. The bacteria successfully colonized the rumen of recipient cattle and persisted through the following winter when there was no leucaena in the diet. 相似文献