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Two insect juvenile hormone analogs, 4[(6,7-epoxy-3-ethyl-7-methyl-2-nonenyl)oxy] benzene and 6,7-epoxy-1-(p-ethylphenoxy)-3,7-dimethyl-2-octene, when applied topically to pupae of the stable fly, Stomoxys calcitrans (L.), were morphogenetically effective against the metamorphosing pupae but did not affect oviposition and development of the hymenopteran parasite, Muscidifurax raptor Girault and Sanders, in the treated pupae. Also, reproductivity of the parent generation of parasites was not affected. 相似文献
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Two compounds with highly potent juvenile hormone activity were isolated and identified from the oil of sweet basil, Ocimum basilicum L., Labiatae. 相似文献
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A nuimber of compounds with terpenoid skeletons attached to various functional groups were prepared and tested for their effects as a juvenile hormone in the yellow mealworm Tenebrio molitor. Several of these compounds showed high activity. 相似文献
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Growth hormone: important role in muscular exercise in adults 总被引:3,自引:0,他引:3
Measurement by radio-immunoassay of growth hormone in the plasma of adults showed consistently low concentrations in subjects in bed in the morning. Exercise caused marked increases except when the subjects ingested carbohydrate during the exercise. 相似文献
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Transition state analogs as ligands for affinity purification of juvenile hormone esterase 总被引:4,自引:0,他引:4
Insect juvenile hormones are metabolized in numerous species of caterpillars by low abundance, highly specific esterases. Because of their role in regulating and possibly disrupting juvenile hormone titer and thus insect metamorphosis, they are of interest to developmental biologists as well as scientists interested in selective insect control. However, the enzymes have defied attempts to purify and characterize them. Juvenile hormone esterase activity can be inhibited by a variety of 3-substituted 1,1,1-trifluoropropanone sulfides. These apparent transition state analogs were used as ligands and eluting agents to purify juvenile hormone esterase from four insect species from 500-fold to over 1000-fold in high yield. After elution from the affinity column, the enzymes were radiolabeled with paraoxon and analyzed by electrophoresis, and the results demonstrate a high degree of purity. Transition state analogs may be useful for the affinity purification of other enzymes. 相似文献
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Wing disks from the last larval instar of the Indian meal moth, Plodia interpunctella (Hübner), were successfully cultured in modified Grace's medium. 20-Hydroxyecdysone induced cuticle deposition in these disks in vitro. This response was enhanced by treating the medium with larval fat body and was inhibited by application of juvenile hormone. 相似文献
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Kolata GB 《Science (New York, N.Y.)》1975,187(4177):635-636
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Juvenile hormone has been implicated in the mediation of several reproduction-related events in adult insects, but had previously been found to play no role in the regulation of sex pheromone production and release behavior ("calling") in moths. In females of the true armyworm moth, Pseudaletia unipuncta, juvenile hormone is shown to be essential to the initiation of both calling behavior and pheromone production. Females without corpora allata, the source of juvenile hormone, do not call and do not produce pheromone, but injection of juvenile hormone into allatectomized females restored these activities. The armyworm's control system has likely evolved in response to the adults' migratory behavior which may necessitate that mating be restricted to the period following migration. 相似文献
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In early autumn, high temperatures terminate diapause in the alfalfa blotch leafminer Agromyza frontella; low temperatures maintain diapause. These responses subserve a thermally malleable dormancy and allow flexibility in the annual number of generations. The view that favorable conditions cannot reverse the course of diapause are contradicted by the data on A. frontella. A better understanding to life history studies and phenological models in insect pest management. 相似文献
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The effect of the injection into rats of analogs of puromycin, 6-dimethylaminopurine, and the aminonucleoside of puromycin on the stimullation of steroidogenesis by adrenocorticotropic hormone was coin pared with that of puromycin and cycloheximide. This stimulation was blocked only by the antibiotics, which also inhibited adrenal protein synthesis. Glycogenolysis is not associated with the primary mechanism of the adrenocorticotropic hormone stimnulation of steroid hormone biosynthesis in rats. 相似文献
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新内标法在斑蝥素测定中的应用研究 总被引:3,自引:0,他引:3
研究了香兰素、正十六烷等物质和样品组分的气相色谱行为,观察这些物质与斑蝥素的分离情况以及样品组分对测定的干扰情况。结果表明,正十六烷与斑蝥素的分离十分理想(分离度〉2.5);用正十六烷做内标的气相色谱法的线型(r=0.9991)和精密度(RSD=3.07%,n=6)较好;样品组分对测定无干扰。新内标法简便,结果准确。可作斑蝥及斑蝥素制品中斑蝥素含量的精确测定之用。 相似文献
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快速测定微量甲醛的新方法--光度测定法研究 总被引:4,自引:0,他引:4
在FeCl3-HCl存在条件下,甲醛与蛋白胨能产生紫色,可以定量测定微量甲醛.测定范围0.1~1.0 mg*L-1,回收率95.08%~103.5%,相对标准差为1.19%(n=6).与乙酰丙酮法相比,用该法测定水发虾仁中甲醛含量,全程只需10 min,具有简单、快速、灵敏度高、使用试剂少等优点,适合现场检测. 相似文献
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A new role for DNA virus early proteins in viral carcinogenesis 总被引:13,自引:0,他引:13
The T antigen proteins encoded by DNA tumor virus early genes are involved in the transformation of normal cells to immortalized neoplastic cells that may or may not be tumorigenic in immunocompetent animals. Studies have been made of the tumorigenicity of DNA virus-transformed cells and the interactions of these cells in vivo and in vitro with immunologically nonspecific host effector cells such as natural killer cells and macrophages. The results imply that the T proteins determine the capacity of transformed cells to induce tumors by governing the level of susceptibility that transformed cells express to destruction by such host cellular defenses. 相似文献
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We present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects. 相似文献