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81.
The Black Sea is the world's largest anoxic basin; it is also a contemporary analogue of the environment in which carbonaceous shales and petroleum source beds formed. Recently, Repeta et al. reported that anoxygenic photosynthesis may be an important component of carbon cycling in the present Black Sea, owing to a shoaling of the chemocline and consequent penetration of the photic zone by anaerobic waters in the past few decades. It has been suggested that this was due to an anthropogenic decrease in freshwater input to the Black Sea, although natural causes were not ruled out. Here we report the distributions of sequestered photosynthetic pigments in eight core samples of sediments from the Black Sea ranging in age from zero to 6,200 years before the present. Our results show that photosynthetic green sulphur bacteria (Chlorobiaceae [correction of Clorobiaceae]) have been active in the Black Sea for substantial periods of time in the past. This finding indicates that the penetration of the photic zone by anaerobic waters is not a recent phenomenon, and suggests that natural causes for shoaling of the chemocline are more likely than anthropogenic ones. 相似文献
82.
Summary The article surveys our knowledge of the normalizing factor, gained from its discovery a quarter of a century ago up to the present time, under the following headings: Discovery; Physiological properties; Isolation and characterization; Structure determination (Identity of the normalizing factor with nicotianamine); Chemical properties; Analysis; Synthesis; Occurrence and physiological role; Related compounds; Prospects. 相似文献
83.
F. M. Goñi J. M. Valpuesta M. C. Barbero E. Rial J. I. G. Gurtubay J. M. Macarulla 《Cellular and molecular life sciences : CMLS》1984,40(2):193-195
Summary The solubilizing effect of Triton X-100 on beef heart submitochondrial particles (ETPH) has been studied under various physiological conditions. Coupled, uncoupled and azide-inhibited ETPH particles have been studied. Quantitative and qualitative differences are found in the proteins solubilized by the detergent from ETPH particles under the various conditions tested.Acknowledgments: This work was supported in part by a grant from a Spanish Comisión Asesora para la Investigación Cientifica y Técnica. M.C. Barbero was recipient of a scholarship from the Basque Government. 相似文献
84.
F. V. DeFeudis L. M. Orensanz Muñoz M. A. Vidal G. Corrochano M. Sanchez del Alamo 《Cellular and molecular life sciences : CMLS》1978,34(9):1169-1170
Summary High-affinity, Na+-independent binding of -alanine to a synaptosomal fraction of rat brain was potently inhibited by glycine and by some other -amino acids, but not by taurine or GABA. This binding mechanism, which was also sensitive to both bicuculline and strychnine, might involve synaptic receptors for both -alanine and glycine.This study was supported in part by Centro Ramón y Cajal and Fundacion Juan March. 相似文献
85.
M. Schwab J. Haas S. Abdo M. R. Ahuja G. Kollinger A. Anders F. Anders 《Cellular and molecular life sciences : CMLS》1978,34(6):780-782
Summary Specific genotypes of the xiphophorine fish develop neoplasms following treatment with N-methyl-N-nitrosourea or X-rays. Several of these neoplasms can be related to the presence of specific chromosomes. The implications of these findings are discussed.Supported by Deutsche Forschungsgemeinschaft through Sonderforschungsbereich 103 Zellenergetik und Zelldifferenzierung, Marburg (projects C 9 and C 10), and by Justus-Liebig-Universität Giessen. We are indebted to Prof. K. Frese, Veterinär-Pathologisches Institut, Giessen and Dr H. D. Mennel, Pathologisches Institut, Freiburg, for their help in the classification of neoplasms. We furthermore thank K. Klinke for breeding the fish. Dedicated to Prof. C. Kosswig on the occasion of his 75th birthday.The paper contains parts of the dissertations of S. Abdo, J. Haas and G. Kollinger.supported by the Egypt ministry of education. 相似文献
86.
Summary 5-bromo-2-deoxyuridine (BUdR) removal from liver DNA in newborn and young adult rats has been demonstrated: it forms the basis of a reliable method to measure DNA repair in tissues provided with detectable DNA synthetic activity.This work was supported by a grant from Consiglio Nazionale delle Ricerche, Rome, and Donazione Teston, Bologna, Italy. 相似文献
87.
Summary Pentobarbital concentrations of 10–100 M selectively inhibited the noradrenaline release evoked by activation of the nicotinic receptors on the terminals sympathetic nerves of the rabbit heart. Higher concentrations also decreased the noradrenaline release induced by KCl or by electrical stimulation of the nerve axons.This paper is dedicated to Professor Dr. G. Malorny on the occasion of his 65th birthday.Acknowledgment: We thank Mrs G. Thielecke for technical assistance. 相似文献
88.
B. Stankiewicz-Choroszucha J. Górski 《Cellular and molecular life sciences : CMLS》1978,34(3):357-358
Summary It was shown in the rat that mobilization of intramuscular triglyceride during exercise is controlled by the adrenergic system.Acknowledgments. The work was supported by the Polish Academy of Sciences, grant No. 10.4.2.01.3.2. 相似文献
89.
Summary The cytoplasm of the restrictive form of the amycelial mutant ofNeurospora crassa, growing on sucrosemedium, contains paracrystalline, microfilamentous inclusions and mitochondria with internal membranous whorls lacking in acetate-grown cultures.The support of the Fonds national suisse de la recherche scientifique is gratefully acknowledged. 相似文献
90.
The effect ofγ-irradiation on soil enzyme stability 总被引:1,自引:0,他引:1
R. G. Burns Lindsay J. Gregory G. Lethbridge N. M. Pettit 《Cellular and molecular life sciences : CMLS》1978,34(3):301-302
Summary Arylsulphatase, -1,3 glucanase, phosphatase and urease responded differently to -irradiation (5–50 Mrad) in air-dried and moist soils. In all instances phosphatase was the most stable. The variability between enzymes may be due to inherent biochemical and stuctural characteristics or to their location within the soil microenvironment.Supported by a grant from the NERC. 相似文献