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101.
Eleven flavonol glycosides and two anthocyanins, only one of which was previously identified, were isolated from the flower petals of okra, Hibiscus esculentus L. On the basis of chromatographic, spectral, and degradative evidence, the following structural assignments were made: quercetin 4′-glucoside, quercetin 7-glucoside, quercetin 5-glucoside, quercetin 3-diglucoside, quercetin 4′-diglucoside, quercetin 3-triglucoside, quercetin 5-rhamnoglucoside, gossypetin 8-glucoside, gossypetin 8-rhamnoglucoside, gossypetin 3-glucosido-8-rhamnoglucoside, cyanidin 4′-glucoside, and cyanidin 3-glucosido-4′ glucoside. Some evidence was obtained of a pentahy-droxy, monomethoxy-flavone glycoside. The total flavonoid content in the red portion of the petal was 0.48% of fresh weight; that in the white portion was 2.51%. The two anthocyanins comprised 28.5% of the flavonoid content of the red flower but only a trace of the content of the white. 相似文献
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Summary The plant-infection technique for the estimation of rhizobia, in which small-seeded hosts are grown on agar within test-tubes, is applicable to soils with a moderate rhizobial population (in the order of at least 100/g). Account might have to be taken of skips (less diluted: negative, when more diluted are positive) likely to result, at least in part, from unfavourable conditions for rhizobial survival, multiplication or nodulation. Because of such effects, a sparse population (in the order of (10/g) may not be detected even without dilution (1 g soil per plant tube). Localisation of rhizobia in the soil is likely to be important in determining contact with the plant roots in the dilution count and in sampling from the field. Difficulties with sparsely populated soils can be partly overcome by carefully conducted direct sowings of sterilised seed, preferably in the confines of cores, either left in the field or brought back to the glasshouse. 相似文献
105.
Howard K. Thompson Jr. Robert H. Peter Henry D. McIntosh 《Bulletin of mathematical biology》1966,28(2):167-179
Previously proposed formulae for the quantitative estimation of bidirectional shunts across ventricular septal defects require
determination of the oxygen contents of mixed venous, pulmonary artery, pulmonary venous, and aortic blood. Because these
formulae do not take into account the mixing of oxygenated with unoxygenated blood within the ventricles, their use must result
in underestimation of shunt flows in each direction. A mathematical model for a ventricular defect is examined, in which it
is assumed that mixing of blood occurs in each of six sites in the venae cavae or right atrium, right ventricle, pulmonary
artery, left atrium, left ventricle, and aorta. A total of fourteen streams of blood can flow from one to another of these
mixing sites. As long as complete mixing occurs in the six specified mixing sites, any degree of mixing or non-mixing of the
various streams is permitted. From the equations characterizing the model, formulae are derived in which the shunt flow in
each direction is expressed in terms of the oxygen contents in the six mixing sites and the fractions of blood which enter
the shunt from either side without prior mixing in a ventricular mixing site. The previously reported formulae, which apply
when no ventricular mixing is allowed to occur, lead to theoretical minimum values for the shunt flows in each direction.
At the opposite extreme where all the shunting blood is required to mix in a ventricle before entering the shunt, formulae
for maximum possible shunt flows are also obtained. The absolute values for the left-to-right and right-to-left shunt flows,
which must lie somewhere between the theoretical maximum and minimum values, cannot be computed from blood gas data alone.
This work was supported in part by grant HE-07563 from the National Heart Institute of the National Institutes of Health and
grants-in-aid from the American and North Carolina Heart Associations and the Life Insurance Medical Research Fund.
Work completed during tenure as U.S.P.H.S. post-doctoral fellow. 相似文献
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Evidence on the Basis of the Centromere Effect in the Large Autosomes of Drosophila Melanogaster 总被引:1,自引:1,他引:0 下载免费PDF全文
Peter E. Thompson 《Genetics》1964,49(5):761-769
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Robert Thompson 《BMJ (Clinical research ed.)》1959,2(5160):1179-1180
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