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101.
Te-ning E. Liu Beverly Wolf John Geigert Saul L. Neidleman Janice D. Chin David S. Hirano 《Carbohydrate research》1983,113(1):151-157
The production of solid d-arabino-hexos-2-ulose (d-glucosone) from d-glucose by use of an enzyme, pyranose-2-oxidase (EC 1.1.3.10), is described. The enzyme is extracted from the mycelia of Polyporus obtusus, partially purified, and then immobilized on activated CH-Sepharose 4B. The enzymic conversion of d-glucose into d-glucosone is simple and convenient, and provides a product free from residual d-glucose. Lyophilization of the filtered reaction-solution yields the product, solid d-glucosone. Assay methods have been developed for monitoring the enzymic reaction and evaluating the purity of the final product. 相似文献
102.
C-Glycosylation of 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone was carried out with acetobromo-α-d-glucose, -α-d-galactose, -α-d-xylose, -β-l-arabinose and -αt-L-rhamnose. The respective 6-C-glycosides and 6, 8-di-C-glycosides (excepted for galactose) were isolated and permethylated. MS and TLC comparison confirmed the proposed structures of five natural tricetin-derived C-glycosides. 相似文献
103.
Wolf -Ernst Reif 《Pal?ontologische Zeitschrift》1983,57(1-2):7-20
Hilgendorf’s (1866) publication on the phylogenyof Planorbis multiformis from Steinheim, Swabian Mountains, is one of the most important contributions of paleontology to early Darwinism. At the same time it helped to lay the foundation for paleontological phylogenetics. Hilgendorf’s unpublished dissertation of 1863, the newly rediscovered collection to his dissertation and the document-file ofHilgendorf’s graduation from Tübingen University help to trace back the origin of Hilgendorf’s ideas.Hilgendorf’s collection contains the oldest phylogenetic tree, which is known so far. 相似文献
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Claude Lefevre 《Bulletin of mathematical biology》1983,45(1):11-20
This paper is concerned with a generalization of the simple epidemic model in which the infective population is partitioned
intom classes, each of specific infectiousness. Attention is restricted, however, to the case where all the meeting rates between
two individuals are equal to each other. Both deterministic and stochastic versions are examined. In either case the development
in time of the epidemic process is investigated by exploiting a connection with the standard simple epidemic model. Finally,
it is shown that the technique used also applies to a similar model for the spread of information. 相似文献
107.
Cultured human choriocarcinoma JEG-3 cells secrete an immunosuppressor that inhibits lymphocyte proliferation stimulated by either an antigen or a mitogen. In this study, the immunosuppressive factor was characterized by three methods: ion-exchange and exclusion chromatography, partition in organic solvents, and thin-layer chromatography on silicic acid. This JEG-3 cell factor appeared to be a protein complex of about 150,000–200,000 Da that contained an immunologically active polar lipid. The structural and functional characteristics of JEG-3 cell immunosuppressor are similar if not identical to those of SIF, a suppressor lymphokine derived from T cells. These secretions from transformed trophoblastic cells may correspond to normal placental products or represent a function of malignant cells. 相似文献
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L De Luca H K Kleinman E P Little G Wolf 《Archives of biochemistry and biophysics》1971,145(1):332-337