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101.
Sex recognition in the leopard gecko,Eublepharis macularius (Sauria: Gekkonidae) Possible mediation by skin-derived semiochemicals 总被引:2,自引:0,他引:2
Male leopard geckoes,Eublepharis macularius, rely on skin-derived semiochemicals to determine the sex of conspecifics. Males respond to other males with agonistic behavior while females elicit courtship behavior from males. While females were shedding, males responded to them with agonistic behavior. The same females were courted both before and after shedding. An initial survey of hexane-extracted skin lipids from male and female geckoes revealed fatty acids common to both sexes. Several steroid analogs of cholesterol were unique to males while long-chain methyl ketones were unique to females. Results are discussed in the context of skin lipids serving as pheromones in reptiles. 相似文献
102.
Gang Yong Park Saehun MunYooheon Park Siyeon RheeEric A. Decker Jochen WeissD. Julian McClements Yeonhwa Park 《Food chemistry》2007,104(2):761-767
The influence of interfacial composition on the in vivo digestibility of emulsified and encapsulated lipids was investigated. An electrostatic layer-by-layer deposition technique was used to prepare soybean oil-in-water emulsions that contained lipid droplets coated by lecithin or by lecithin–chitosan. Thirty six 4-week-old male mice were divided into four groups and fed treatment diets for 4 weeks; atherogenic diets supplemented with (A) non-emulsified fat, without chitosan (control), (B) non-emulsified fat, with chitosan, (C) emulsified fat, without chitosan, or (D) emulsified fat encapsulated by chitosan. There were no differences in body weights, food intake, major organ weights, or fecal fat contents between all treatment groups, where total fat absorption was >90%. The results suggest that encapsulation of lipids by chitosan does not inhibit their in vivo digestibility, even though previous studies indicate that chitosan does inhibit their in vitro digestibility. Consequently, it should be possible to use chitosan to microencapsulate lipids and lipid-soluble components without compromising their bioavailability, although further human studies are needed to confirm this. 相似文献
103.
Florian Kühbeck Werner Back Martin Krottenthaler 《Journal of the Institute of Brewing》2006,112(3):222-231
Different lauter turbidities (standard 43 EBC vs. turbid 82 EBC on average) were obtained by variation of the lauter procedure, particularly deep raking, in this study. The resulting worts were used for repitching the respective yeast into six subsequent fermentation cycles. The resulting beers were investigated in terms of flavour quality, flavour stability, non‐biological stability and foam stability. Worts gained from turbid lautering showed very similar analytical data compared to the controls (except for a slight but significant increase in linoleic acid). There was an improvement in fermentation performance in terms of a pH decrease and a decrease in extract. The resulting beers were quite similar, and the staling indicators increased slightly, but not significantly, due to turbid lautering. Both types of beer were evaluated on tasting as being of a high flavour quality and neither a professional panel nor a non‐professional (customer) panel was able to distinguish the difference, between standard and turbid lautering, in terms of fresh and forced aged beers. Due to turbid lautering the non‐biological stability appeared to be slightly, but not significantly, decreased while on the other hand the foam stability was significantly improved due to turbid lautering. In conclusion, fermentation performance may be improved by more turbid lautering, and the negative consequences often reported for the resulting beers appear to be overestimated, since the quality parameters of the final beers had not deteriorated significantly. 相似文献
104.
The inhibition of the growth of the green algaChlorella pyrenoidosa by the lipids of the cyanobacteriumAphanizomenon flos-aquae is associated with the fractions containing long-chain unsaturated fatty acids. A sterol present inAphanizomenon has been identified as poriferasterol. 相似文献
105.
O. Rajonhson C. Rocrelle M. Delmas A. Gaset 《Journal of the American Oil Chemists' Society》1991,68(8):585-587
In the manufacturing of leather from lambskins, skin degreasing is an important preliminary stage in which excess fats are
removed. A new solvent-phase degreasing process, which leads to a complete recovery of extracted fats, has been studied and
scaled up in our laboratory. In this paper, we study the characteristics of these extracted fatty substances that have not
been reported previously. Extracted fats which, up to now, were considered waste, can be used. Different methods have been
proposed for their possible utilization. 相似文献
106.
The cellular lipid composition of one flor-forming strain of Saccharomyces cerevisiae during fermentation and the subsequent period of film formation with different oxygen levels was studied. Irrespective of fermentation conditions, only those yeasts which came into contact with oxygen after fermentation formed a flor film. After the fermentation, these yeasts entered an adaptation phase in which the percentage of oleic acid increased considerably at the expense of other long-chain fatty acids. Their phospholipid contents remained high, as well as the unsaturation index of their fatty acids and the ergosterol/phospholipids ratio was maintained below 1. These changes allowed an increased viability of yeasts in the wine of up to 80% and the acquisition of sufficient hydrophobicity and floatability to reach the surface and form flor film. 相似文献
107.
Edward Durnoford Fereidoon Shahidi 《Journal of the American Oil Chemists' Society》2002,79(11):1095-1102
The FA composition of selected tissues of all six species of eastern Canadian phocid seals: bearded seal (Erignathus barbatus), gray seal (Halichoerus grypus), harbor seal (Phoca vitulina), harp seal (P. groenlandica), hooded seal (Cystophora cristata), and ringed seal (P. hispida) was determined to detect possible differences among different tissues and species. A univariate approach was used to examine
differences among different tissues and species separately, and a multivariate approach was taken in examining differences
among different species and tissues simultaneously. Findings indicated that FA composition depended on both tissue and species
of seal. However, differences were most apparent among tissues. Several unique features of the FA compositions were identified.
Blubber was found to be high in the monounsaturated FA, but low in arachidonic acid and dimethyl acetals. Brain tissue lipids,
on the other hand, were high in dimethyl acetals and DHA. Lung tissue lipids were very high in palmitic acid, and heart tissue
lipids had a higher content of linoleic acid than did lipids of other tissues examined. Thus, the proportions of FA constituents
in different tissues were different, most probably due to their varying functional requirements. 相似文献
108.
The Chemistry and Biology of 6‐Hydroxyceramide,the Youngest Member of the Human Sphingolipid Family
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Andrej Kováčik Dr. Jaroslav Roh Prof. Dr. Kateřina Vávrová 《Chembiochem : a European journal of chemical biology》2014,15(11):1555-1562
Sphingolipids are crucial for the life of the cell. In land‐dwelling mammals, they are equally important outside the cell—in the extracellular space of the skin barrier—because they prevent loss of water. Although a large body of research has elucidated many of the functions of sphingolipids, their extensive structural diversity remains intriguing. A new class of sphingolipids based on 6‐hydroxylated sphingosine has recently been identified in human skin. Abnormal levels of these 6‐hydroxylated ceramides have repeatedly been observed in atopic dermatitis; however, neither the biosynthesis nor the roles of these unique ceramide subclasses have been established in the human body. In this Minireview, we summarize the current knowledge of 6‐hydroxyceramides, including their discovery, structure, stereochemistry, occurrence in healthy and diseased human epidermis, and synthetic approaches to 6‐hydroxysphingosine and related ceramides. 相似文献
109.
110.
Alcohol dehydrogenases catalyse the reversible oxidation of alcohols to aldehydes or ketones, with concomitant reduction of NAD(+) or NADP(+) . Adh1p is responsible for the reduction of acetaldehyde to ethanol, while Adh2p catalyses the reverse reaction, the oxidation of ethanol to acetaldehyde. Lack of Adh1p shifts the cellular redox balance towards excess NADH/NADPH and acetaldehyde, while absence of Adh2p does the opposite. Yeast mutant adh1Δ had a slow growth rate, whereas adh2Δ grew like the isogenic wild-type (WT) during prediauxic shift fermentative metabolism. After 48 h WT and mutants reached the same number of viable cells. When exponentially growing (LOG) cells were exposed to calcofluor white, only mutant adh1Δ displayed an irregular deposition of chitin. Quantitative analyses of both LOG and stationary-phase cells showed that adh1Δ mutant contained significantly less ergosterol than cells of WT and adh2Δ mutant, whereas the erg3Δ mutant contained extremely low ergosterol pools. Both adh1Δ and adh2Δ mutants showed higher-than-WT resistance to heat shock and to H(2) O(2) but had WT resistance when exposed to ultraviolet (UV) light and the DNA cross-linking agent diepoxyoctane, indicating normal DNA repair capacity. Mutant adh1Δ was specifically sensitive to acetaldehyde and to membrane peroxidizing paraquat. Our results link the pleiotropic phenotype of adh1Δ mutants to low pools of ergosterol and to reductive stress, and introduce the two new phenotypes, resistance to heat shock and to H(2) O(2) , for the adh2Δ mutant, most probably related to increased ROS production in mitochondria, which leads to the induction of oxidative stress protection. 相似文献