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排序方式: 共有255条查询结果,搜索用时 15 毫秒
61.
Cheng-Hua Zhao Jocelyn G. Millar Kun-Hui Pan Cai-Sheng Xu 《Journal of chemical ecology》1998,24(8):1347-1353
Field trials were conducted with each synthetic enantiomer (>98% ee) and blends of the two synthetic enantiomers of the female-produced sex pheromone (10,14-dimethylpentadecyl isobutyrate) of the tea tussock moth, Euproctis pseudoconspersa. Male moths were attracted to each enantiomer alone and to various blends of them. Short syntheses of both enantiomers of the pheromone from commercially available (R)- and (S)-citronellyl bromide and a method of checking the enantiomeric purity of the citronellyl bromide enantiomers are described. 相似文献
62.
63.
Phenolic antioxidant compounds, including resveratrol, are associated with reduced risk of cancer and cardiovascular disease, and delayed ageing. This study aims to quantify synergistic enhancement of phenolics and antioxidants in peanuts by combinations of ultrasound (US)–UV treatments, compared to either US or UV, and determine optimum parameters for combined US–UV process. LC–MS confirmed the bioactive phenolics: trans-resveratrol, trans-piceid, and p-coumaric-, caffeic-, and ferulic-acids, which achieved maximum increases, with combined US–UV, compared to US or UV; as did total phenolics (TP), TEAC, and ORAC. Optimum parameters for a combined US–UV process will provide up to 4.8 μg/g trans-resveratrol, 170 μg/g p-coumaric acid, and 150 μM TE/g ORAC or >100% that found in red wines; 1.0 μg/g trans-piceid, 2.6 μg/g ferulic acid, 1.48 mg GAE/g TP, and consumer acceptance ?5. Optimum combined US–UV resulted in 1.3× or 2.3× the trans-resveratrol concentrations in US or UV, respectively, suggesting synergistic effect of UV and US in enhancing resveratrol in peanuts. 相似文献
64.
AbstractCalcium sulfonate complex greases have excellent extreme pressure, antiwear, and anticorrosion properties and are widely applied in rolling bearings, particularly in humid environments. In this article, the shear stability of dry and water-contaminated lubricating calcium sulfonate complex greases is described using a novel aging method. Unlike lithium and polyurea greases, no shear softening is observed for the dry greases due to the good mechanical stability of the particle-like thickener structure. For water-contaminated greases, no water separation was found during the prolonged aging. Instead, a homogeneous water–calcium sulfonate thickener micellar structure is generated. These micelles function as apparent thickeners and effectively increase the thickener concentration, which thickens the grease. This may explain why calcium sulfonate complex grease has excellent water absorption properties. 相似文献
65.
Male-Produced Aggregation Pheromone of the Cerambycid Beetle <Emphasis Type="Italic">Rosalia funebris</Emphasis> 总被引:2,自引:2,他引:0
Ann M. Ray Jocelyn G. Millar J. Steven McElfresh Ian P. Swift James D. Barbour Lawrence M. Hanks 《Journal of chemical ecology》2009,35(1):96-103
We report the identification, synthesis, and field bioassays of a volatile, male-produced aggregation pheromone of a long-horned
beetle, the banded alder borer, Rosalia funebris Mots. Headspace collections from males contained a major male-specific compound, (Z)-3-decenyl (E)-2-hexenoate, and several minor components, identified as (Z)-3-decenol, (Z)-3-nonenyl (E)-2-hexenoate, and (Z)-3-decenyl (E)-3-hexenoate. The antennae of both males and females responded strongly to (Z)-3-decenyl (E)-2-hexenoate. We collected significant numbers of adult R. funebris in field bioassays using traps baited with this compound. This pheromone structure is unprecedented in the literature of
cerambycid pheromones and distinct from the more common diol/hydroxyketone pheromone motif of many other species of the diverse
subfamily Cerambycinae. This is the first pheromone identified for a species in the tribe Rosaliini.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
66.
Christelle Guédot Jocelyn G. Millar David R. Horton Peter J. Landolt 《Journal of chemical ecology》2009,35(12):1437-1447
Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, uses a female-produced sex attractant pheromone. We compared the chemical profiles obtained from cuticular extracts of diapausing and post-diapause winterform males and females to isolate and identify the pheromone. Post-diapause females produced significantly more of the cuticular hydrocarbon, 13-methylheptacosane, than post-diapause males and diapausing females. In olfactometer assays, conspecific males were attracted to synthetic racemic 13-methylheptacosane, whereas females were not, indicating that the behavioral response to this chemical is sex-specific. Furthermore, 13-methylheptacosane was as attractive to males as a cuticular extract of females, suggesting that this chemical was largely responsible for the female attractiveness. A field study showed that males but not females were attracted to 13-methylheptacosane, confirming the olfactometer results. This study provides evidence that 13-methylheptacosane is a sex attractant pheromone for C. pyricola winterform males. This is the first identification of a sex pheromone in the Psylloidea. Our results open the path to developing monitoring tools and possibly new strategies for integrated pest management of this insect. 相似文献
67.
Laboratory medicine has undergone many changes over the last two decades in terms of automation, information systems, the use of dry chemistry and the advent of point-of-care testing, just to mention a few. There is a major shift in emphasis at the present time. There is a strong focus on cost containment as reimbursement for testing is ratcheted down. In addition, “clinical resource management” has become the phrase of the moment. Clinical resource management stresses the need to evaluate what testing, either laboratory or diagnostic imaging, is actually necessary in any particular disease state. Predetermined pathways are designed so that in a disease such as asthma, the length of stay in the hospital and the testing modalities are predetermined, although obviously exceptions can be made in unusual circumstances. 相似文献
68.
Ann M. Ray James D. Barbour J. Steven McElfresh Jardel A. Moreira Ian Swift Ian M. Wright Alenka ?uni? Robert F. Mitchell Elizabeth E. Graham Ronald L. Alten Jocelyn G. Millar Lawrence M. Hanks 《Journal of chemical ecology》2012,38(9):1151-1158
Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium “sp. nov. Laplante” is (2R,3R)-2,3-hexanediol, and provide evidence from field bioassays and electroantennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T. depsarium “harrisi” LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines. 相似文献
69.
Plucker Jonathan A.; Holden Jocelyn; Neustadter David 《Canadian Metallurgical Quarterly》2008,2(4):190
Creativity in movies is a topic of growing interest in both the psychological and the marketing literature. Much research has been invested into determining the impact of cinematic quality on film success and finding successful predictors of cinematic creativity. For these reasons, research into the way creativity is measured in film is of considerable importance. This study examines a variety of measures of cinematic quality (movie ratings from a variety of sources) and determines the degree of agreement among different types of measures, the predictive value of these measures, and the effect of the timing of these measures on their predictive value. Results indicate that there is a high degree of agreement among types of movie ratings, that reviews through release day tend to be marginally higher than those that appear later, and that reviews are more highly correlated with later box office success (gross) than with early box office success. A surprising result of this study was that the number of ratings a movie received was a slightly better predictor of box office success than the actual movie ratings. Possible explanations for and implications of these results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.
Gas hydrates are ice-like compounds composed of water molecules that encapsulate natural gas molecules in a very compact form. Three groups of CO2 hydrate-bearing sand specimens were formed using a specialized triaxial test apparatus at different temperature and different pressure to examine the physical effects, such as stress and deformation changes, of hydrate dissociation on the surrounding soil. The triaxial test data indicate: (1) the higher the pressure, the higher hydrate content; (2) the lower the temperature, the higher hydrate content; (3) the greater the amount of gas hydrate initially present in the specimen, the greater the reduction of effective stress upon dissociation and the lower strength; and (4) dissociation of even a small percentage of gas hydrates will cause a dramatic reduction in the soil strength and could lead to failure. 相似文献