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Imperfect Symmetry: Thermodynamics in Ecology and Evolution 总被引：1，自引：0，他引：1
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Phosphorylase kinase of the liver: deficiency in a girl with increased hepatic glycogen 总被引：4，自引：0，他引：4
Studies of a child with glycogenosis revealed an increased concentration of glycogen and low phosphorylase activity in her liver. Using mixtures of homogenates of the patient's liver and of normal liver, we found the low phosphorylase activity to be caused by a deficiency of phosphorylase kinase and not of hepatic phosphorylase. The fact that phosphorylase activity was restored to normal values by the addition of phosphorylase b kinase from rabbit muscle substantiates this conclusion. 相似文献
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Zhao J Muhammad I Dunbar DC Mustafa J Khan IA 《Journal of agricultural and food chemistry》2005,53(3):690-693
Maca (Lepidium meyenii) has been used as a food in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements, with claims of anabolic and aphrodisiac effects, although the biologically active principles are not fully known. In an earlier chemical investigation, two new alkamides and a novel fatty acid, as well as the N-hydroxypyridine derivative, macaridine, were isolated from L. meyenii. Further examination has led to the isolation of five additional new alkamides, namely, N-benzyl-9-oxo-12Z-octadecenamide (1), N-benzyl-9-oxo-12Z,15Z-octadecadienamide (2), N-benzyl-13-oxo-9E,11E-octadecadienamide (3), N-benzyl-15Z-tetracosenamide (4), and N-(m-methoxybenzyl)hexadecanamide (5). Their structures were established by spectrometric and spectroscopic methods including ESI-HRMS, EI-MS, (1)H, (13)C, and 2D NMR, as well as (1)H-(15)N 2D HMBC experiments. In addition, the identity of N-benzyl-15Z-tetracosenamide (4) was confirmed by synthesis. These compounds have been found from only L. meyenii and could be used as markers for authentication and standardization. 相似文献
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Onisko BC Tambling DR Gorder GW Diaz DG Ericson JL Prisbylla MP Spillner CJ 《Journal of agricultural and food chemistry》2002,50(7):1922-1928
The metabolism of fonofos, a thiophosphonate insecticide, was investigated in mature lettuce (Latuca sativa), beet (Beta vulgaris), and wheat (Triticum aestivum). Six new metabolites were identified by LC-MS and LC-MS-MS analysis using fast atom bombardment (FAB) and packed capillary LC columns with application of the on-column focusing technique. These methods provided the sensitivity required to identify unknown metabolites that were present in the mature plants at only 20-230 ppb. Structural elucidation was facilitated by use of fonofos labeled with both carbon-14 and carbon-13 in the phenyl ring. In all three plants fonofos was converted to a glucose conjugate of thiophenoxylactic acid. Oxidation of the glucose conjugate gave isomeric sulfoxides in all species examined. Thiophenoxylactic acid was found esterified to malonic acid in lettuce. In beets, S-phenylcysteine was found as its malonic acid amide. A second metabolite unique to beets was N-(malonyl)-[2[(ethoxyethylphosphinothionyl)oxy]phenyl]cysteine. This novel structure was confirmed by synthesis. 相似文献
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Interest exists in the commercial culture of sponges in the Pohnpei region of the Federated States of Micronesia. Sponge culture is appealing in that capital and labor investment is minimal. Investment requirements for a 0.4-ha sponge farm totals $650. Average annual production costs total $500. The sponge farm yields 2,400 sponges per 0.4 ha annually. Annual net returns are approximately $1,744 per 0.134 ha component, beginning in Year 4. Profitability is most sensitive to changes in opportunity wage rate, survival rate, and market price. Commercial sponge farming in Pohnpei shows promise as a source of supplemental income. 相似文献
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Spawning time and size of wild and nonnative cultured female Atlantic salmon (Salmo salar L.) were studied in the River Vosso, Norway. Cultured immigrants were smaller, and peak spawning occurred 21 and 26 days earlier relative to wild salmon in 1991 and 1992, respectively. It was calculated that hatching and initial feeding of offspring of cultured females peaked 12 and 9 days earlier in spring 1992 and 19 and 8 days earlier in spring 1993 relative to offspring of wild females. Spawning time of the cultured salmon is similar to most Norwegian salmon populations and to cultured fish in other streams. In the River Vosso it also overlaps with that of brown trout (Salmo trutta L.), which may increase hybridization. The early time of breeding in nonnative fish indicates local adaptation in this trait in wild salmon. The consequences of early breeding of cultured fish are unpredictable in relation to spring temperatures but probably reduce their relative breeding success. The smaller size may also reduce the success of cultured females. 相似文献
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