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Résumé En conclusion de quelques nouvelles réactions et de la mesure de son spectre d'absorption, la formule I est proposée pour la Sempervirine C19H16N2, l'alcaloïde jaune deGelsemium sempervirens.  相似文献   

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Summary The structure of Visamminol (I), a compound isolated fromAmmi visnaga bySmith, Pucci, andBywater, has been elucidated by degradation and by a comparison of the UV.-spectra of I and its derivatives with those of other chromones.  相似文献   

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Résumé La structure du réseau spatial de l'azulène cristallisé a été déterminée à l'aide des rayons X. Les valeurs des constantes du réseau sont en général les mêmes que celles trouvées parMisch etvan der Wyk. Au contraire, la statistique des interférences observées montre des différences importantes et conduit au groupe spatial P 21/a, à la place de P 21 et P 21/m indiqué par les auteurs cités.

Erstmals hergestellt vonPl. A. Plattner undA. St. Pfau, Helv. chim. acta20, 224 (1937).  相似文献   

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Summary In the literature has been described that the further bromination of 4,4-dibromo-koprostanon results in the formation of a 2,4,4-tribromo-koprostanon. In this paper it is shown that the tribromo-compound obtained from koprostanon is a2,4,6-tribromo-cholestenon.  相似文献   

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Summary Results of partial hydrogenation support the assumption that lactaroviolin belongs to the azulen group.  相似文献   

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Summary The author shows mathematically and experimentally, that a mechanical frequency-analysis in the cochlea is possiblewithout resonance and that the yielding and damping of the basilar membrane are determinative.  相似文献   

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Summary Larvae ofSalamandra salamandra quadrivirgata Dürigen and tadpoles ofXenopus laevis Daud, treated with a percutaneous application of thyroxin, show a more intensive calcification of their skeletal system after a precocious metamorphosis. The calcified area of bones is increased; additional centres of calcification can be distinguished in quite a number of other skeletal elements. By thyroxin-soaked agar implants in the hindlimbs ofAmbystoma mexicanum, deposition of calcium salts is furthered in the bones of the leg treated, as well as in the adjacent pelvic girdle, thus demonstrating that the thyroid hormone exerts a direct effect upon calcification. It is supposed that during normal metamorphosis the thyroid gland plays an equal part in the process of calcification in the skeletal system.  相似文献   

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Summary Inhibition of active cation transport through the red cell membrane by cardiac glycosides is not accompanied by alteration of phosphate metabolism (ATP, ADP, 2,3-diphosphoglyceric acid) in contrast to the action of iodoacetate. This fact suggests that the cardiac glycosides act directly on the membrane transport mechanism.  相似文献   

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Summary The red-brown haemovanadin which is contained in the haemolysate (Henze Solution) of blood cells of the ascidiaPhallusia mamillata Cuvier is a chromoproteid with trivalent vanadium as the central atom and sulphuric acid bound coordinatively. It is found to have a molecular weight of 24,400±1,900 according to the estimation of the diffusion coefficient (D=6.87±0.2 · 10–7 cm2 · s–1 at pH 2.5–2.8).

Dem Entdecker des Hämovanadins zum 80. Geburtstag gewidmet.  相似文献   

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Summary Fishes and aquatic amphibians are able to detect and locate moving bodies and even obstacles at some distance by means of their lateral-line sense organs (Ferntastsinn). As was shown experimentally, the main physical process involved in these reactions are certain local damming phenomena in front of the moving object (rise of pressure, displacement of water particles). Obstacles cause an alteration of the damming phenomena produced by the moving animal's body itself (increase of water resistance).Kramer's different view is rejected; he overlooked the existence of damming phenomena and was not aware of the fact thatXenopus laevis reacts to surface waves even when the animal is totally submerged.  相似文献   

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Summary The weight has been measured of the granuloma produced after implantation of the same foreign body in the kidneys, the testes, the liver and the subcutaneous tissue of male rats. It was found that granulomae in the testes and liver are nearly twice as heavy as in the kidney or in the subcutaneous tissue. Enhancement or inhibition of this reaction by treating the animals with cortexone shows organ-dependent effects on granuloma formation.  相似文献   

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Summary The authors have succeeded in isolating alliin in a pure, crystalline form and in defining its properties. Alliin is characteristic for certain kinds of garlic; it contains sulphur and nitrogen and represents the initial substance of garlic oil. Alliin itself has no bactericidal action. Upon decomposition—caused by a specific concomitant enzyme, alliinase—the highly bactericidal substance, allicin, is produced. Further decomposition yields the volatile, sharply-odorous allyl-sulphides.  相似文献   

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