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41.
作者应用前 S_1、前 S_2和 HBsAg/a 单克隆抗体,用免疫斑点法(Immuno-spot)检测同一批的乙肝表面抗原分别经加热灭活和三步化学灭活后的前 S_1和前 S_2蛋白保留情况,比较了两种工艺对前 S_1和前 S_2蛋白的影响。结果表明;加热灭活可保留前 S_1和前 S_2蛋白,三步化学灭活使前 S_1和前 S_2蛋白丢失,从抗原组成上看,加热灭活后的抗原更接近自然抗原。首次报告了含有前 S_1蛋白的乙肝疫苗,并对前 S_1和前 S_2蛋白在乙肝血源疫苗中的可能作用进行了讨论。 相似文献
42.
43.
The significance of the alkyl group at the C-4 of (+)-trans-verbenyl acetate, which is the sex pheromone mimic of the American cockroach, was investigated. Seven alcohols possessing an ethyl, propyl, or dimethyl group at this position of the 6,6-dimethylbicyclo[3.1.1]heptane skeleton were synthesized and evaluated by behavioral assay. All of the alcohols were inactive, while three of four acetates of the 2-alcohols induced sexual behavior in male cockroaches at the 0.02 or 0.5 mg dosage level, either of which is many orders of magnitude higher than the threshold level of the natural sex pheromones (10–8 mg). Among the acetates, the compounds with a methyl group or an -oriented ethyl group at C-4 showed the highest activity. The results are discussed in terms of spatial requirements of the molecules for interactions with the receptor.Studies on the sex pheromone mimic of the American cockroach, (+)-trans-verbenyl acetate. Part VIII. For Part VII, seeComp. Biochem. Physiol.,70A: 229–234 (1981). 相似文献
44.
The pheromone system of the summer fruit tortrix mothAdoxophyes orana (Fischer von Röslerstamm) consists of a mixture ofcis-9- andcis-11-tetradecen-1-ol acetate (cis-9- andcis-11-TDA, respectively) in a ratio of 9:1. Substitution of one or both of these compounds by related unsaturated acetates reduced the attractancy. Onlycis-11-TDA could be replaced bycis-11-tridecen-1-ol acetate (cis-11-TriDA), although the 9:1 mixture ofcis-9-TDA andcis-11-TriDA was less attractive in the field than the pheromone system itself. The major component of the pheromone system of the leaf rollerClepsis spectrana (Treitschke)(cis-9-TDA:cis-11-TDA=1:9) could also be replaced bycis-11-TriDA, again with some reduction in attractancy. 相似文献
45.
The influence has been studied of the partial pressure of hydrogen (0–30 kPa) upon the coking rate of a Cr2O3/Al2O3 commercial catalyst during 1-butene dehydrogenation. Coke deposition has been analysed using a monolayer-multilayer reversible coke growth model (MMRC model). This model provides good fits to the experimental data, within the range of partial pressure of H2 studied, and allows us to estimate the main kinetic parameters involved in the coking-deactivation process. The results obtained reveal a dual effect of hydrogen: competition against 1-butene for the active sites and the removal of coke precursors from the catalyst surface. Bom effects diminish the coking rate as the H2 partial pressure is increased. 相似文献
46.
Field survey of the geometrical isomers of 7,9-dodecadienyl alcohol, acetate, and aldehyde has resulted in attractants and inhibitors for three species of tortricid moths.Epinotia silvertoniensis and an undescribedEpinotia sp. were all attracted to (Z,Z)-7,9-dodecadienyl acetate. AnotherEpinotia sp. was attracted to (Z,Z)-7,9-dodecadienyl acetate and (Z,Z)-7,9-dodecadien-1-ol. Electroantennogram data and inhibition patterns for one of theEpinotia sp. are also reported. In addition,E. criddleana was attracted to lures containing (E)-9-dodecenyl acetate. 相似文献
48.
Scott Camazine 《Journal of chemical ecology》1985,11(9):1289-1295
Visual and acoustic cues may serve as aposematic signals that warn predators of poisonous foods. Olfactory aposematism, the use of innocuous odors as warning signals for toxic foods, is another possible means of alerting an animal that a potential food item is unpalatable. Although it has been suggested that olfactory aposematism might be the principle mode of warning utilized by plants in their defense against herbivores, experimental evidence is lacking. This study demonstrates that the opossum,Didelphis virginiana, can utilize an innocuous volatile compound found naturally in a mushroom as a warning signal for a delayed illness caused by mushroom toxin. This supports the contention that characteristic odors of toxic plants may serve a warning function, protecting herbivores from being poisoned and plants from being consumed. 相似文献
49.
Short syntheses of (Z)-7-dodecen-1-yl acetate, (Z)-7-tetradecen-1-yl acetate, (Z)-9-dodecen-1-yl acetate, and (Z)-9-tetradecen-1-yl acetate from 7-hydroxyheptanal and 9-oxononanoic acid precursors obtained by oxidative cleavage of easily available aleuritic acid are reported. The key step in these syntheses is a stereoselective Wittig reaction between aldehyde and alkyl-phosphonium salt. Wittig-Horner type reaction of 7-hydroxyheptanal and diethyl cyanomethylphosphonate gave the ,-unsaturated nitrile derivative which after protection of the hydroxyl group was reduced to the corresponding aldehyde. Wittig reaction of the latter, followed by acetylation, completed the synthesis of (E,Z)-7,9-dodecadien-1-yl acetate, the sex pheromone of the European grapevine mothLobesia botrana Schiff. 相似文献
50.
侧链为亚乙氧基结构的EVOH梳型聚合物的合成 总被引:1,自引:0,他引:1
以乙烯-乙烯醇共聚物(EVOH)为原料,制备了一种主链为疏水的聚乙烯链段,侧链具有亚乙氧基结构的多羟基梳形聚合物,用元素分析法、凝胶渗透色谱法、核磁共振谱法对其进行了结构表征;用热重分析法和示差扫描量热法对其热学性能进行了表征。结果表明,接枝后产物的玻璃化转变温度在-52--40℃之间,熔点在55~600℃之间,由于侧链的引入破坏了EVOH的结晶,因此梳形聚合物的热分解温度比EVOH降低了约20℃。 相似文献