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M. C. GACULA JR. R. W. WASHAM II S. A. BEARD J. E. HEINZE 《Journal of sensory studies》1986,1(1):47-53
In-house use consumer test data from four studies dealing with three pairs of household products and a pair of antiperspirant products were examined for significant carry-over (product usage order) effects, which would confound the analysis of treatment (product) effects. In each study, two products were compared using a two-period crossover design. One hundred twenty panelists participated in each study. A forced choice preference scale or a 9-point hedonic scale was used to obtain responses from various sensory attributes. In all studies, the estimates of carry-over effects were not significant at the 5% level. Transformation of hedonic scale data into preference dichotomy also gave estimates of carry-over effects which were not significant at the 5% level, but led to a loss of test sensitivity for detecting treatment differences. The authors recommend that all comparative crossover design studies in sensory evaluation be monitored for carry-over effects and that statistically determined sample size should be used to reduce the possibility of obtaining significant carry-over effects. 相似文献
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SYNOPSIS. The mechanism of carbohydrate dissimilation was studied in cell-free extracts prepared from mass cultures of the trichomonads. Evidence for the presence of all the enzymes associated with the Embden-Meyerhof glycolytic scheme was obtained. Several enzyme systems directly associated with the glycolytic pathway were examined. Two of these, alcohol dehydrogenase and phosphorylase, were not demonstrated in the T. vaginalis extract. The absence of phosphorylase in the presence of a very high glycogen concentration in the cell (20.8%) suggests the possibility of an alternate route. A very active TPN-linked "malic enzyme" was also demonstrated, although no functional citric acid cycle is known for this trichomonad. Based on the experimental evidence and collateral data, a functional Embden-Meyerhof system was suggested for T. vaginalis. 相似文献
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George R. McGhee JR. 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1976,9(2):111-136
Four benthic marine communities occur in the clastic facies of the prograding Upper Frasnian-Lower Famennian (Upper Devonian) Foreknobs Formation in the Central Appalachians along the Allegheny Front in Maryland, West Virginia, and Virginia. Deep-water, rapidly prograding environments were inhabited by the Ambocoelia-Chonetes Community, dominated by an epifauna of unattached brachiopods. Offshore bar environments were inhabited by the Cyrtospirifer-Camarotoechia Community, exhibiting adaptations to shallow-water, high-energy conditions and probably lowered salinities. Shallow-water, sublittoral environments were inhabited by the Atrypa-Cypricardella Community, a community in which existed a variety of life habitats and a diverse epifaunal and infaunal association of brachiopods and bivalve molluscs. The Leptodesma-Tylothyris Community flourished in nearshore bar-protected environments in the southern region of the study area, whereas in the north the Cyrtospirifer-Camarotoechia Community inhabited nearshore environments in conjunction with the onshore development of a large fluviodeltaic system. 相似文献
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Sigurdsson V Fridriksdottir AJ Kjartansson J Jonasson JG Steinarsdottir M Petersen OW Ogmundsdottir HM Gudjonsson T 《In vitro cellular & developmental biology. Animal》2006,42(10):332-340
Summary Attempts to study endothelial-epithelial interactions in the human breast have been hampered by lack of protocols for long-term
cultivation of breast endothelial cells (BRENCs). The aim of this study was to establish long-term cultures of BRENCs and
to compare their phenotypic traits with the tissue of origin. Microvasculature was localized in situ by immunohistochemitry
in breast samples. From this tissue, collagen-rich stroma and adipose tissue were dissected mechanically and further disaggregated
to release microvessel organoids BRENCs were cultured from these organoids in endothelial specific medium and characterized
by staining for endothelial markers. Microvessels were a prominent feature of intralobular tissue as evidenced by immunostaining
against endothelial specific markers such as CD31, VE-cadherin, and von Willebrand factor (VWF). Double staining against VE-cadherin
and lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) showed that blood and lymphatic vessels could be distinguished.
An antibody against CD31 was used to refine protocols for isolation of microvasculature from reduction mammoplasties. BRENCs
retained critical traits even at high passage, including uptake of low-density lipoprotein, and had E-selectin induced upon
treatment with tumor necrosis factor-α. The first signs of senescence in passage 14 were accompained by gain of trisomy 11.
At passage 18 cells showed chromosomal aberrations and growth arrest as revealed by β-galactosidase staining. We demonstrate
here that breast microvasculature may serve as a large-scale source for expansion of BRENCs with molecular and functional
traits preserved. These cells will form the basis for studies on the role of endothelial cells in breast morphogenesis. 相似文献
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Cold shock and heat shock: a comparison of the protection generated by brief pretreatment at less severe temperatures 总被引:1,自引:0,他引:1
Abstract Brief exposure to low (0o C) or high (40o C) temperature elicits a protective response that prevents injury when the flesh fly, Sarcophaga crassipalpis Macquart, is subjected to more severe cold (-10o C) or heat (45o C). Both the low and high temperature responses were found in all developmental stages of the fly, but were most pronounced in the pupal and pharate adult stages. The protective responses generated by brief exposure to 0 or 40o C appear similar in that both result in a rapid acquisition of cold or heat tolerance and a loss of protection after the flies are returned to 25o C. The protection generated by chilling is obvious within 10 min of exposure to 0o C while a 30 min exposure to 40o C is required to induce the high temperature protection. High temperature protects against cold shock injury within a narrow range (around 36o C) but we have no evidence that low temperature can protect against heat injury. We previously demonstrated that the rapid increase in cold tolerance correlates with concomitant increases in glycerol concentration, but in this study we found no significant elevation in glycerol in heat-shocked flies. Thus the physiological and biochemical bases for the rapid responses to cold and heat appear to be different. 相似文献