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991.
Heuskin S Lorge S Godin B Leroy P Frère I Verheggen FJ Haubruge E Wathelet JP Mestdagh M Hance T Lognay G 《Pest management science》2012,68(1):127-136
BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting predators and parasitoids of aphids. Various formulation criteria were optimised with respect to semiochemical encapsulation capacity. Moreover, the optimised formulation was characterised by texturometry and confocal microscopy. The slow-release rates of semiochemicals were calculated in laboratory controlled conditions. The attractiveness of semiochemical formulations towards Aphidius ervi was demonstrated by olfactometry. RESULTS: Two major parameters were highlighted in encapsulation optimisation: the type of alginate (Sigma L) and the type of crosslinker ion (Ca2+). Other formulation parameters were optimised: ionic strength (0.5 M), Ca2+ (0.2 M) and alginate (1.5%) concentrations and the maturation time of beads in CaCl2 solution (48 h). After physical characterisation of beads, semiochemical slow-release measurements showed that alginate formulations were efficient sesquiterpene releasers, with 503 µg of E-β-farnesene and 1791 µg of E-β-caryophyllene totally released in 35 days. The efficiency of semiochemical alginate beads as attractants for female parasitoids was demonstrated, with high percentages of attraction for semiochemical odours (88 and 90% for E-β-farnesene and E-β-caryophyllene respectively) and significant statistical results. CONCLUSION: Semiochemical alginate beads can be considered as efficient slow-release systems in biological control. These formulations could be very useful to attract aphid parasitoids on crop fields. Copyright © 2011 Society of Chemical Industry 相似文献
992.
993.
庄元忠 《浙江大学学报(农业与生命科学版)》1998,(Z1)
报道如何在常温常压下提取蜂花粉内含物,并保持花粉产品不受污染。结果表明,应用仿生学原理,蜂花粉经生物加工技术处理之后,能够促使花粉的萌发孔萌发沟极度张开,其内含物可以在常温常压下,从萌发孔、萌发沟处释放出来,逐渐向提取溶剂中扩散。内含物释放后花粉粒成为空壳,提取液不需高温消毒灭菌,产品即能达到食品卫生标准要求。 相似文献
994.
氟在猪体内的代谢及高氟的毒害作用 总被引:1,自引:0,他引:1
本文综述了氟在猪体内的吸收、蓄积、排泄、对猪毒害作用及其作用的机理。 相似文献
995.
放牧强度对高寒灌丛草甸土壤CO_2释放速率的影响 总被引:18,自引:0,他引:18
在中国科学院海北高寒草甸生态系统定位站,研究放牧强度对土壤CO2释放速率的影响及其与环境条件的关系。结果表明,CO2释放速率具有明显的日变化规律,日最大值在12∶00~14∶00h出现,最低值出现于凌晨6∶00~8∶00h。轻牧和重牧区日释放速率分别为7.774±5.577 g·m-2·d -1和6.977±4.947 g·m-2·d-1。CO2释放速率具有明显的季节变化,最大值均出现在7月,而冬季则最低。CO2释放速率的日变化主要受气温和地表温度的制约,与气温和地表温度呈极显著的正相关(P<0.01)。CO2释放速率的季节动态与气温和地温(0~30cm)呈极显著的正相关(P<0.01)。放牧使CO2释放速率降低。 相似文献
996.
小鼠对温和气单胞菌口服缓释微球疫苗的免疫应答 总被引:2,自引:1,他引:1
采用中华鳖温和气单胞菌(Aeromonas sobria,As)Z-1株灭活全菌液,以生物降解性高分子材料为载体,制成微球疫苗,口服免疫ICR小鼠,测定了血清中凝集抗体效价、血液中单核-巨噬细胞的吞噬活性以及对活菌攻击的免疫保护力.结果显示小鼠微球疫苗口服免疫后第4周,血清中凝集抗体效价和血液中单核-巨噬细胞的吞噬指数均可达到与灭活菌液注射组相当的水平(P>0.05),明显高于灭活菌液口服组(P<0.01);免疫后第7~12周,微球疫苗口服组血清凝集抗体效价显著高于灭活菌液注射组(P<0.05);微球疫苗口服组和灭活菌液注射组的免疫保护力均为87.5%,而灭活菌液口服组不能提供有效的保护,与对照组死亡率相同(100%).结论认为,中华鳖气单胞菌口服微球疫苗具有缓释作用;以可生物降解的微球作为中华鳖气单胞菌口服疫苗的载体系统具有潜在的优势. 相似文献
997.
生长激素(PST)脂质体的药物代谢动力学研究 总被引:2,自引:1,他引:1
本文研究了生长激素(PST)脂质体在仔猪体内的药物代谢动力学,分析了血浆中生长激素浓度时间的变化曲线,确定其释药模型为单室模型,求出了各项动力学参数,揭示PST脂质体的缓释效果显著,缓释时间长达7d以上。 相似文献
998.
Calculation of the energy release rate with finite element method (FEM ) is conducted. The concrete beam model is meshed using a method without need of considering the crack-tip singular element. Two columns of nodes, which belong to the right-and left-parts of the beam, respectively, are generated on the central line of the model and released one after another in a proper sequence. Energy release rate is evaluated based on the virtual crack closure technique. Comparison between the calculated values and theoretical values is made, which shows that they are in good agreement. 相似文献
999.
The heat release rate is the key factor that determines fire hazards. In order to find out the characters of heat release rate and their relation with other parameters. The authors introduce the oxygen consumption principle which cone calorimeter applies, and then expound the calculation of heat release rate in detail. The heat release rate of several kinds of representative materials has been studied by means of cone calorimeter in the different irradiances. Test results shows that HRR and TFI^-1/2 vary linearly with the irradiances. 相似文献
1000.
The core of performance-based building fire protection design consists of the establishment of fire scenario,the enactment of fire and the simulation of fire and smoke-flow development.These are most important for performance-based building fire protection design.An unreasonable enactment or pre-digestion could result in a biggish error between the simulation outcome and the actual condition.In this paper,several emphases and some issues worth much attention are introduced and analyzed.In addition,a few important issues in simulating the fire and smoke-flow development related to Field Model are analyzed in detail. 相似文献