AS350B3e直升机航空喷施雾滴飘移分布特性

为了探究安装有AG-NAV Guía系统的AS350B3e直升机进行喷施作业时的雾滴飘移规律,以轻型机载北斗RTK差分系统获取的精准作业参数(时间、速度、高度、轨迹)为参考,进行了不同作业参数喷施试验。研究了该直升机以4种不同飞行速度范围进行单向式喷施作业时,对应的有效喷幅区域范围及雾滴飘移分布规律,对比了添加航空助剂对雾滴飘移距离及飘移量的影响。结果表明:有效喷幅区域的位置受自然风速和风向变化的影响,会向直升机航线下风向区域有不同程度的偏移;当直升机分别以70、90、100、120 km/h 4种速度参数进行喷施作业时,随着飞行速度的增大,有效喷幅宽度呈现先缓慢增大后急剧减小的趋势,100 km/h的飞行速度为有效喷幅宽度变化的峰值拐点;当侧风风速为1.1~2.3 m/s时,目标喷雾区的最小宽度在喷雾区域下风向水平距离27.61~48.94 m的范围内,且下风向受飘移影响距离均接近或小于下风向有效喷幅宽度,同时研究还发现雾滴粒径在200μm以下的雾滴更容易发生飘移,因此在作业时要预留至少50 m以上缓冲区(安全区)并合理选择航空喷头以避免药液飘移产生的危害;航空助剂的使用对于雾滴飘移量减轻效果显著,在同等作业条件下,添加航空助剂能够使雾滴飘移量减少33.94%。该研究结果可为直升机的喷施系统性能改进提供参考,对合理喷施农药、减少飘移、提高农药利用率具有重要意义。     

Adjuvant Effects of Recombinant Plasmids of Porcine IL-4 and IFN-γ to Cysticercosis cellulosae Vaccines in Mice and Pigs

To investigate the adjuvant potential of porcine IL-4 and IFN-γ in mice and pigs, the genes of porcine IL-4 and IFN-γ were cloned and the recombinant mammalian expression plasmids were constructed for in vivo expression of the cytokines. Adjuvant effects of recombinant expression plasmids of IL-4 and IFN-γ （pcDNA-IL-4, pcDNA-IFN-γ） co-administrated with Cysticercus cellulosae crude antigen or TSOL18 recombinant protein antigen have been carried out in mice and pigs, respectively. We have demonstrated that recombinant plasmids of the cytokines as an adjuvant could induce stronger immune response in mice and pigs. With the C. cellulosae parasite antigen, porcine pcDNA-IL-4 induced higher specific antibody of immunized mice than pcDNA-IFN-γ. But pcDNA-IFN-γ is significantly stronger than that of no adjuvant or empty plasmids with the antigen control group. For the TSOL18 recombinant protein antigen vaccine, pcDNA-IL-4 still had a stronger ability to enhance specific antibody in swine than pcDNA-IFN-γ （P 〈 0.01）, but the immune protective rate was lower in challenged pigs （only 68.7%）. Although pcDNA-IFN-γ showed lower specific antibody, the protection rate was very high （91%） than other group （P 〈 0.01）. This study indicated that the recombinant expression plasmids of porcine IL-4 and IFN-γ display stronger adjuvant effects to C. cellulosae vaccine, further research should be carried out for understanding of the interaction mechanism.     

DNA vaccine encoding avian influenza virus H5 and Esat-6 of Mycobacterium tuberculosis improved antibody responses against AIV in chickens

The H5 gene of avian influenza virus (AIV) strain A/chicken/Malaysia/5744/2004(H5N1) was cloned into pcDNA3.1 vector, and Esat-6 gene of Mycobacterium tuberculosis was fused into downstream of the H5 gene as a genetic adjuvant for DNA vaccine candidates. The antibody level against AIV was measured using enzyme-linked immunosorbent assay (ELISA) and haemagglutination inhibition (HI) test. Sera obtained from specific-pathogen-free chickens immunized with pcDNA3.1/H5 and pcDNA3.1/H5/Esat-6 demonstrated antibody responses as early as 2 weeks after the first immunization. Furthermore, the overall HI antibody titer in chickens immunized with pcDNA3.1/H5/Esat-6 was higher compared to the chickens immunized with pcDNA3.1/H5 (p < 0.05). The results suggested that Esat-6 gene of M. tuberculosis is a potential genetic adjuvant for the development of effective H5 DNA vaccine in chickens.     

Avian CD154 enhances humoral and cellular immune responses induced by an adenovirus vector-based vaccine in chickens

Recombinant adenoviral vectors have emerged as an attractive system for veterinary vaccines development. However, for poultry vaccination a very important criterion for an ideal vaccine is its low cost. The objective of this study was to test the ability of chicken CD154 to enhance the immunogenicity of an adenoviral vector-based vaccine against avian influenza virus in order to reduce the amount of antigen required to induce an effective immune response in avian. Chickens were vaccinated with three different doses of adenoviral vectors encoding either HA (AdHA), or HA fused to extracellular domain chicken's CD154 (AdHACD). Hemagglutination inhibition (HI) assay and relative quantification of IFN-γ showed that the adenoviral vector encoding for the chimeric antigen is able to elicit an improved humoral and cellular immune response, which demonstrated that CD154 can be used as a molecular adjuvant allowing to reduce in about 50-fold the amount of adenoviral vector vaccine required to induce an effective immune response.     

4种助剂对异丙隆防除菵草的增效作用

为了比较4种助剂Silwet 806、红太阳A8、激健、安融乐对异丙隆防除菵草Beckmannia syzigachne的增效作用及机制,采用整株生物测定法测定4种助剂与异丙隆混用后对菵草的生物活性及对小麦的安全性;采用仪器分析法测定4种助剂对异丙隆药液的表面张力、叶面接触角、干燥时间和在叶面上的沉积量的影响。结果表明:添加4种助剂后异丙隆防除菵草的ED90分别降低为553.11、626.31、819.93、841.54 g/hm2,但异丙隆与Silwet 806混用后对小麦安全性下降。添加4种助剂后,异丙隆药液的表面张力和叶面接触角显著降低,药液在叶面上的干燥时间缩短,沉积量增加,其中红太阳A8的上述指标显著优于激健和安融乐,能够较好地实现异丙隆减量增效的目的。     

有机硅助剂在苹果炭疽叶枯病化学防控中的减药增效作用评价

有机硅助剂具有低毒、易降解的特性,可提高农药的药液展布性和渗透性。本研究分别采用室内离体叶片法和田间试验评价了2种有机硅助剂对吡唑醚菌酯和代森锰锌防治苹果炭疽叶枯病的减药增效作用。室内离体试验结果表明,杀菌剂浓度减半的处理以及模拟雨水冲刷处理均导致吡唑醚菌酯和代森锰锌的防效显著下降;而添加了有机硅助剂后,2种处理的防效显著提高,并且恢复到与正常施药量相同的水平。田间试验结果表明,正常情况下杀菌剂浓度减半后防效显著下降;而施用有机硅助剂后,浓度减半的吡唑醚菌酯和代森锰锌的防效显著高于不施用有机硅的处理。本研究结果表明,施用有机硅助剂可以在减少化学农药实际用量的情况下,保持较高的防效,这对于化学农药的减施增效具有重要意义。     

Effect of cell mediated immunity regulation of duck enhanced by duck IFN-α eukaryon expression plasmid and inoculated with DPV attenuated vaccine by gene-gun

In order to study the effect of cell mediated immunity regulation of duck IFN-α eukaryon expression plasmid (pcDNA-SDIFN-α) on duck plague virus (DPV) attenuated vaccine in ducks, pcDNA-SDIFN-α was administered to 28-day-old ducks at doses of 1, 3 and 6 μg per duck, respectively, by gene-gun. PBS and empty vector pcDNA were used as control. Fifteen days later, all ducks were injected with DPV attenuated vaccine and blood samples were collected at 3, 7, 14, 21, 28, 35, 49, 63 and 84 days after injection. T-lymphocyte proliferation tests (MTT) were used to detect the T-lymphocyte proliferation in the peripheral blood (PBL) of ducks. Blood samples collected at 7, 14, 21, 28, 35 and 49 days after injection were detected by fluorescence-activated cell sorter (FACS) for recording the number of CD₃ ⁺ T-lymphocytes of ducks. Results were as follows: (1) Reaction of T-lymphocytes in PBL to ConA (OD value) of ducks treated with pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 3–84 days. There were highly significant differences between the 1 μg per duck group and the two control groups in 3–84 days (P ⩽ (0.01), between the 3 μg per duck group and the two control groups in 3–84 days (P ⩽ 0.01, P ⩽ 0.05), and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). The significant difference was also present between the groups of 1, 3 and 6 μg per duck in 3–35 days (P ⩽ 0.05). However, there was no significant difference between the 3 and 6 μg per duck groups (P ⩾ 0.05). The pcDNA control group was higher than PBS control group, but no difference was detected (P ⩾ 0.05). (2) Change of the number of CD₃ ⁺ T-lymphocytes in ducks administered with different doses of pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 7–49 days. The change in the 1 μg per duck group was significantly higher than that in PBS and pcDNA control groups in 14–49 days (P ⩽ 0.01). There were significant differences between the 3 μg per duck group and the two control groups in 21–49 days (P ⩽ 0.01, P ⩽ 0.05) and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). However, no significant differences among the groups of 1, 3, and 6 μg per duck groups (P ⩾ 0.05) and between the two control groups (P ⩾ 0.05) were found. The results indicated that pcDNA-SDIFN-α administered 15 days before injection of DPV-attenuated vaccine could significantly enhance cellular immunity induced by DPV-attenuated vaccine. pcDNA-SDIFN-α is an excellent DPV-attenuated vaccine molecular adjuvant and the best result can be obtained with the dose of 1 μg per duck of pcDNA-SDIFN-α inoculated by gene-gun. __________ Translated from Acta Veterinaria et Zootechnica Sinica, 2007, 38 (10): 1066–1071 [译自: 畜牧兽医学报]     

农药助剂的应用与研究进展

农药助剂种类繁多,应用广泛,并且对农药剂型的发展与产品的质量和安全有着密切的关系。随着对农药安全性和环境影响的要求不断提高,农药助剂应用与管理问题显得日益重要。本文分析和讨论了我国农药助剂的应用发展以及国外对农药助剂的管理情况,对于农药剂型产品的开发和助剂的管理有一定借鉴作用。     

羔羊痢疾、大肠杆菌病、羊猝狙、羊肠毒血症四联油佐剂灭活菌苗研制及预防试验的研究

用标准的魏氏梭菌C58-2 (B型 )、C59-2 (C型 )、C60 -3 (D型 )菌株和贵州省畜牧兽医科学研究所分离的病原性羔羊大肠杆菌地方菌株CH9812 (O119)、SC993 8(O2 4 )株 ,采用先进的乳化工艺按一定的比例研制成四联油佐剂灭活苗和四种油佐剂单苗。进行了羔羊痢疾、羊猝狙、羊肠毒血症、羔羊大肠杆菌病四联油佐剂灭活苗与四种油佐剂单苗进行性能试验比较研究 ,结果是 :四联与单苗之间免疫效力差异不显著 (P >0 0 5 )。免疫后 2 1天攻毒 ,试验羊能抵抗魏氏梭菌 1 0× 1 0 9CFU/ml× 2ml毒素的静脉攻击 ,也能抵抗病原性大肠杆菌 1 0× 1 0 9CFU/ml× 3ml皮下攻击 ,保护率为 1 0 0 %。四联苗和单苗大剂量免疫试验羊 ,未发现任何副作用。证明四联油佐剂苗安全可靠。四联苗免疫期实验证明 :羔羊痢疾、羊猝狙、羊肠毒血症免疫期为 1年 ;羊大肠杆菌病为 8个月。研究结果证明 :四联油剂苗安全可靠 ,其免疫效力、免疫期、免疫安全性能达到或高于同类单价苗的效力标准。用羔羊痢疾、羊猝狙、羊肠毒血症、羔羊大肠杆菌病四联苗佐剂灭活菌苗在册亨、水城、龙里、罗甸等县的 6 0 0户养羊专业户中进行了野外田间试验。共免疫接种不同年龄、不同品种、不同性别的山羊 2 86 0 0只。结果 :四联苗较分次使用单苗接种减少羊     

GnRH类似物疫苗免疫去势效果的影响因素

利用GnRH类似物疫苗主动免疫动物机体可达到与手术去势类似的效果,同时避免了手术去势对动物机体产生的影响。抗原、佐剂、免疫次数、免疫剂量以及免疫时间都会对其免疫效果产生影响。采用GnRH类似物疫苗免疫动物通常需要有力的佐剂以及多次加强免疫来克服个体反应的差异性。