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91.
研究了铝(Ⅲ)或铁(Ⅲ)-二溴苯基荧光酮(DB-PF)-溴化十六烷基二甲基氨基乙酸(CDMAA)体系的显色条件。提出用双波长分光光度法同时测定铝和铁的简便、快速和灵敏的方法,测定铝的波长对为562 ̄648nm,测定铁的波长对为596 ̄551nm,该法用于无机材料立方氮化硼中微量氧化铝和氧化铁的直接测定,结果满意。 相似文献
92.
载牛冠状病毒N蛋白壳聚糖微球的免疫效果评价 总被引:1,自引:0,他引:1
为了对壳聚糖分子作为佐剂的缓释效果进行免疫学评价,本研究合成了牛冠状病毒DB2毒株N蛋白基因的3'端第487位~1287位碱基,用大肠杆菌对其进行了高效表达,通过SDS-PAGE电泳分离、电洗脱纯化该牛冠状病毒N蛋白(BCV N).以戊二醛为交联剂,采用乳化交联的方法制备空白壳聚糖微球.利用吸附法制备载BCVN蛋白的壳聚糖微球,通过肌肉注射途径免疫BALB/c小鼠,用间接ELISA方法检测免疫鼠血清中的抗体水平,由此评价壳聚糖微球对BCVN的缓释作用和佐剂效应.结果表明,壳聚糖微球的形态较好、表面光滑、分散性较好,平均粒径为6.50±1.77μm,电势分布在36 mV,吸附BCV N蛋白的壳聚糖微球在体内所产生的免疫效果明显优于唯N蛋白组,说明载BCV N蛋白的壳聚糖微球在体内具有一定的缓释效果,使N蛋白在体内缓慢释放而长时间诱导抗体的产生,该研究结果为以壳聚糖微球作为疫苗佐剂积累了实验数据. 相似文献
93.
鸡新城疫、传染性支气管炎、传染性法氏囊病三联活疫苗的研究 总被引:1,自引:1,他引:0
鸡新城疫(ND) La Sota、传染性支气管炎(IB) H120和传染性法氏囊病(IBD) B87弱毒株适当稀释后等量混合,经10日龄SPF鸡胚同胚接种联合培养,收获含毒鸡胚液和胎儿混合制成ND、IB、IBD三联活疫苗。接种7~14日龄SPF雏鸡7 d产生抗体,14~21d达到高峰,免疫期70 d以上,与单苗同步免疫并攻击强毒,试验结果无显著性差异。以10个使用剂量免疫SPF雏鸡,无ND、IB、IBD临床症状和剖检病变,其安全性和效力检验均达到相应单苗的标准要求。 相似文献
94.
方林 《江西农业大学学报》1989,(1)
国营林场之间由于经营规模、土壤、气候、地形地貌、地理位置和交通条件等区别,各种经济指标的高低不一,而难以实行整体评价和横向对比。本文运用线性规划与对偶规划成功地对江西12个国营林场运用定量的方法作出了经营效果的综合评价。 相似文献
95.
96.
J B Jorgensen 《Acta veterinaria Scandinavica》1977,18(4):532-544
A porcine strain of Mycobacterium avium, Serotype 2, was used for intravenous inoculation of pigs in doses 5, 1, 10−1, 10−2 and 10−3 mg (1 mg = 78 × 106 viable units), 2 pigs per dose.Dose 5 mg proved fatal for both of the inoculated pigs, which were killed in extremis 64 and 69 days, respectively, after inoculation. Dose 1 mg caused clinical disease in 1 of 2 pigs, but was not lethal. Post mortem, the clinically affected pigs showed a generalized granulomatous tuberculosis. The other pig given 1 mg and the pigs given smaller doses, showed no clinical signs, and lesions and presence of acid-fasts were mostly limited to the lymph nodes of the lung, liver and digestive tract.All the pigs showed delayed hypersensitivity to avian PPD tuberculin (1000 t.u.) and some of them cross-reacted with human PPD tuberculin (1000 t.u.). The clinically affected pigs gave a very weak response to tuberculin, the others a strong response.The smallest dose capable of establishing an infection and producing tuberculous lesions was not determined, but seems to be less than 10−3 mg (78000 viable organisms). 相似文献
97.
F Biancifiori A Fioroni 《Comparative immunology, microbiology and infectious diseases》1983,6(3):247-252
The antigenic and pathogenetic relationship between pigeon Newcastle disease virus (NDV) isolates during outbreaks of 1982 in Italy and reference pathogen and non-pathogen NDV-strains were investigated.The pigeon-isolates were slow-eluters and showed a thermostability at 56°C of over 30 min. They proved to be lentogenic as measured by the mean-death-time in chicken-embryos, and between lentogenic and mesogenic as measured by the Hanson test. They failed to produce plaques in chicken-embryo-fibroblasts and showed high pathogenicity for experimentally infected pigeons, low-pathogenicity for quails and were not pathogenic for chickens. They were antigenically different from the LaSota strain as measured by the cross-HI-test and induced considerable seroconversion in inoculated animals. The existence of a lentogenic neurotropic pigeon-pathogenic strain was considered. 相似文献
98.
本试验采用人工方法给新生犊牛接种反刍食团,并对犊牛瘤胃内容物pH值、纤毛虫以及反刍规律等进行了研究。试验结果表明,犊牛各周龄pH值变化、接种组与未接种组之间无显著差异,但与常规组相比,在4周龄时差异则显著。接种组2周龄时发现在瘤胃中有纤毛虫,未接种组则在5周龄时发现纤毛虫,常规组在6周龄时发现纤毛虫。反刍开始时间接种组早于常规组,但各组牛的每次反刍延续时间均随着周龄的增加而延长。 相似文献
99.
A.D.?IwaroEmail author J.-M.?Thévenin D.R.?Butler A.B.?Eskes 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(2):173-182
The detached pod test by spray method (DPT-SM) was developed to facilitate the screening of cacao genotypes for resistance
to Phytophthora pod rot (PPR) caused by Phytophthora palmivora. The test has been adopted in many cacao research institutes, and it is imperative that its validity be assessed. In this
study, 40 genotypes from various cacao groups were selected and screened for resistance to PPR by DPT-SM and field observations.
Significant variation was observed in the reactions of the selected accessions based on the disease rating scale for DPT-SM
and the percentage pod rot from field observations. A correlation coefficient of 0.68 (P<0.001) was observed between the results of year-1 and year-2 field observations. However, relatively lower correlation values
were obtained between year-3 and year-1 (r=0.32; P=0.041) and year-3 and year-2 (r=0.35; P=0.025) field observations. A higher level of susceptibility was observed in the third year of field observations (63%) than
in the first (15%) and second (25%) years. This suggests that the predisposing factors for PPR were unstable between the years
of field observations. Data obtained from the Trinidad and Tobago Meteorological Services showed that the rainfall in November
of the third year was higher than the amounts of rainfall in November of the first 2 years of field observations. This month
marks the beginning of the main pod harvest season (November–February) and the high rainfall in November of the third year,
and the presence of large number of mature pods may account in part for the increase in PPR in the third year of field observations
than in the first 2 years. This shows that absolute reliance could not be placed on a single year of field observations in
determining clonal resistance to PPR. A correlation coefficient of 0.59 (P<0.001) was obtained between the result of year-2 field observations and DPT-SM. Relatively lower correlation values were
observed between DPT-SM and year-1 (r=0.55; P<0.001) and year-3 (r=0.44; P=0.005) field observations. The result of DPT-SM, however, shows a higher correlation (r=0.66; P<0.001) with the average of years 1–3 field observations. This suggests that a stronger association may exist between the
result of DPT-SM and the cumulative data on field observations for a period longer than 3 years. The correlation (r=0.66; P<0.001) observed in this study confirms the usefulness of DPT-SM as an effective method of assessing clonal resistance to
PPR and predicting field reaction in the long term. Since field observations are labour intensive and expensive to conduct
on a yearly basis, the DPT-SM offers a cheaper and effective means of assessing clonal resistance to PPR. Being a non-destructive
inoculation method, the DPT-SM provides a suitable option for cacao collections in genebanks to be assessed. It is also a
cost-effective method for use in cacao breeding programmes. Based on its reliability, the DPT-SM has been adopted in the CFC/ICCO/IPGRI
cocoa project ‘Cocoa Germplasm Utilization and Conservation: A Global Approach’ for the assessment of cacao resistance to
PPR in several cocoa producing countries. 相似文献
100.
Abhinandan?Deora Yasuyuki?HashidokoEmail author Md.?Tofazzal?Islam Satoshi?Tahara 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(4):311-322
A total of 150 bacteria were isolated from rhizoplanes of the host and non-host plants of a phytopathogenic Peronosporomycete Aphanomyces cochlioides. Upon screening, 5% of the isolates were evaluated as antagonists as they inhibited radial growth of A. cochlioides AC-5 hyphae in a dual culture assay. In addition, those antagonistic bacteria also induced characteristic morphological alterations in the A. cochlioides AC-5 hyphae that grew towards bacterial colonies. Hyphal morphological alterations observed in AC-5 and other tested strains of Peronosporomycetes included excessive branching, curly growth, unusually longer and pointed tip formation and swelling; all of these were comparable to the alterations induced by known antimicrobial compounds. Among the antagonistic bacteria, Pseudomonas sp. strain EC-S101 induced a unique branching pattern (tree-like) in AC-5 hyphae by continuous apical bifurcation of successive hyphae, where increases in number of branches and hyphal area were linearly correlated with time up to 10 h. Our observations suggested that the pathogen might have lost its ability of normal branch production; however maintained the capability of self-branching. Soluble extracts from the culture fluids of Pseudomonas sp. strain EC-S101 and Stenotrophomonas maltophilia EC-S105 induced similar excessive branching and curly growth in A. cochlioides hyphae as the respective bacterium. These results revealed that bacterial metabolites appeared to be responsible for induction of morphological alterations. Interestingly, the antagonistic bacteria that induced hyphal morphological alterations, also efficiently suppressed in vivo damping-off disease caused by AC-5. We suggest that antagonistic rhizoplane bacteria have the capability to induce diverse morphological alterations in Peronosporomycetes hyphae during in vitro interactions. Hyphal morphological alterations associated with growth inhibition and the induction of characteristic morphological changes indicate antagonistic activity against the Peronosporomycete. 相似文献