共查询到20条相似文献,搜索用时 15 毫秒
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Summary A comparison is made between aneuploid off-springs of triploid females mated with diploid or triploid males ofPleurodeles waltlii. In the latter case, embryonic lethality is raised, and abnormalities are more severe. The disturbances affect morphogenesis, embryonic growth and physiological differentiation. At the cellular level, nuclear and nucleolar degenerative changes are conspicuous. 相似文献
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M. Larpent-Gourgaud M. P. Aumaître 《Cellular and molecular life sciences : CMLS》1977,33(12):1601-1602
Summary The radiations coming from Blanc Brillant de Luxe' fluorescent stimulate the growth and ramification of protonema ofCeratodon purpureus (Hedw.) Brid. This stimulation is caused by red light (660 nm). Multidirectional lightening is more favorable than unidirectional exposition. 相似文献
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R. Matthey 《Cellular and molecular life sciences : CMLS》1946,2(12):497-498
Summary The chromosomal sets of five species ofPerlodidæ (Plecoptera) are given in the present paper. The sexual chromosomes belong to three distinct types:X-O,X
1-X
2,X
1-X
2-X
3. The author shows that these three types are likely derived from the most primitive patternX-Y, by translocation and inversion. 相似文献
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G. de Haller Ch F. Ehret Rosmarie Naef 《Cellular and molecular life sciences : CMLS》1961,17(11):524-526
Summary (1) Control of cell orientation and knowledge of the plane of sectioning are indispensable (but generally ignored) requirements for studies of the development of cellular constituents. (2) A simple technique that meets these requirements for the electron microscope is given. (3) As applied toParamecium, it is shown that the ciliary complexes of the new gullet develop outside of the old one, and that invagination begins at the anterior end of the gullet anlage.
Travail effectué dans le cadre d'une recherche faite en collaboration avec les Instituts d'Histologie et de Biophysique, grâce à une subvention de «Fritz Hoffmann-La Roche-Stiftung zur Förderung wissenschaftlicher Arbeitsgemeinschaften in der Schweiz». 相似文献
Travail effectué dans le cadre d'une recherche faite en collaboration avec les Instituts d'Histologie et de Biophysique, grâce à une subvention de «Fritz Hoffmann-La Roche-Stiftung zur Förderung wissenschaftlicher Arbeitsgemeinschaften in der Schweiz». 相似文献
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Summary The thermodynamic study of systems in which stationary (non equilibrium) states were possible, led one of us (I. P.) to a number of general conclusions. In the present paper these conclusions are summarized and briefly discussed from a biological standpoint. It appears that the evolution of such systems is towards states with the least production of entropy (per mass unit) compatible with the conditions imposed. In the case of living matter this corresponds approximately to states of minimum metabolism. During this evolution the entropy contained in the system may decrease whilst the heterogenity increases. But this increase in heterogenity can only take place when there is a decrease in the entropy production, that is an evolution of the metabolism. We are thus led to suggest a physicochemical interpretation of Lamarchism. Finally we call attention to the fact that the moderation principle ofLe Chatelier-Braun is not limited to equilibrium states. 相似文献
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A. Lacassagne Ng. Ph. Buu-Hoï Mlle L. Corre J. Lecocq R. Royer 《Cellular and molecular life sciences : CMLS》1946,2(2):70-71
Summary A series of derivatives of triphenylethylene have been tested and some of them found to possess interesting oestrogenic properties; the relations between chemical constitution and oestrogenic activity have been discussed. 相似文献
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At the beginning of the 1890s, Schwarz and Peano (independently of each other) showed that Serret’s definition of the area
of a surface was flawed. This paper first aims at describing the various methods that the mathematicians have used for correcting
Serret’s reasoning; its second goal is to compare and to present more in detail two solutions: Lebesgue’s notorious construction
and Peano’s definition. 相似文献
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G. Turian 《Cellular and molecular life sciences : CMLS》1957,13(8):315-317
Summary Premeiotic chromospheres in the immature resistant sporangia (RS) ofAllomyces lose their basophily after treatment with trichloracetic acid, perchloric acid or ribonuclease.
Postmeiotic chromospheres in the mature RS, becoming the nuclear caps of the ‘reduced’ zoospores, do not stain with toluidine
blue or pyronine after ribonuclease digestion.
It is concluded that, as gametic and zoosporic nuclear caps, pre- and postmeiotic chromospheres are transitory cytoplasmic
organites rich in RNA.
相似文献
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I. Grundland H. Krzywicka M. Chojnacki 《Cellular and molecular life sciences : CMLS》1957,13(11):449-451
Summary Electrophoretic analysis of bacterial substance proves the departure, from UV irradiated microbes screened from light for a certain time, of substances which were responsible for increasing the charge density by surface unit during the first moments which follow the irradiation by UV rays. Spectrophotometric analysis of liquids having contained these bacilli proves concommitantly the diffusion of those substances from the bacterial substance to the aqueous phase and reveals their nature. The photoreactivity which is possible during the first moments following the UV irradiation of bacilli, due to the presence of the fragments of depolymerisation of nucleic acid macromolecule in the bacterial substance, becomes impossible after the departure (diffusion) of those fragments to the aqueous phase. These observations seem to show that the phenomenon of photo-reactivity is connected with the repolymerisation of the macromolecule primitively divided of desoxyribonucleic acid. 相似文献
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R. Lallier 《Cellular and molecular life sciences : CMLS》1963,19(11):572-573
Summary In the presence of actinomycin D (20–40 µg/ml), the development of the eggs of the sea urchin,Paracentrotus lividus, is slowed from the late morula and stopped at the blastula stage. The development is immediately stopped in the blastula treated with actinomycin D (20–40 µg/ml). The inhibitory effects of actinomycin D are prevented by deoxyribonucleic acid. Actinomycin D does not exert animalizing or vegetalizing effects. However, the enhancing of vegetalizing action of lithium and the weakening of animalizing effects of zinc ions and Evans blue have been observed in the presence of actinomycin D. These observations may reflect some difference in the state of dependence of differentiation of entomesodermic and ectodermic structures towards the nucleus. 相似文献
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R. A. Boissonnas 《Cellular and molecular life sciences : CMLS》1947,3(6):238-239
Summary The qualitative and quantitative analysis of synthetic mixtures of non-isomeric and isomeric methylated glucoses, as present in the hydrolysate of methylated glucopolysaccharides, has been achieved by hydrogenation of the methylated sugars to the corresponding methylated hexitols, esterification withp-azobenzoylchlorid, and chromatographic analysis on activated alumina. 相似文献
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G. Deicha 《Cellular and molecular life sciences : CMLS》1948,4(2):67-68
Summary A case of twin formation (Fig. 1) in rock-salt is crystallographically studied and a structural interpretation is proposed (Fig. 2). The twinning is produced experimentally by supersaturation of sodium chloride solutions, and appears as an outstanding case of the complications in the process of crystallization caused by desequilibrium during genesis and growth. 相似文献
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Summary In the case of mineral carcinogenic substances, the relation already established for organic carcinogenic substances with histamine is apparent. Silver, nickel, cobalt, chronium, and berryllium form well-characterized complexes with histamine. 相似文献
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A. A. Elens 《Cellular and molecular life sciences : CMLS》1958,14(8):274-276
Summary Whereas in homozygous state the geneebony noticeably diminishes the sexual activity of the males, it can on the contrary increase it in heterozygous state; but this heterotic effect depends in a large measure on the direction of the crossing, and also on the genic and cytoplasmic context. It depends moreover on the temperature.The role of this activity in the populations whereebony is made to compete with its normal allel is discussed briefly. 相似文献
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Simone Hatem 《Cellular and molecular life sciences : CMLS》1959,15(6):219-220
Summary Histamine, which is a constituent of neurons shows a particular affinity for cancer-producing substances but not for the non-cancer-producing isomers of such substances. 相似文献