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91.
S. F. Wang J. C. Braekman D. Daloze J. Pasteels P. Soetens N. V. Handjieva P. Kalushkov 《Cellular and molecular life sciences : CMLS》1996,52(6):628-630
The isolation of N-quinaldyl-L-arginine·HCl (1) from the CoccinellidaeSubcoccinella-24-punctata is reported. The structure, first established on the basis of the analysis of the spectral properties of1, has been confirmed by synthesis. The alkaloid is of endogenous origin and markedly deterrent to ants. 相似文献
92.
93.
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
94.
Summary The intensity of sound-induced convulsions in the genetically epilepsy-prone rat (GEPR) was reduced in a dose related fashion by intracerebroventricular administration of dobutamine, (1 agonist), terbutaline (2 agonist) or phenylephrine (1 agonist). BHT-920 (2 agonist) did not cause a dose-related decrease in sound-induced convulsion intensity. Binding studies showed that whole brain and receptor densities (Bmax) were normal while the Kd was increased for the ligand in GEPR brain.Acknowledgment. We are most grateful to Boehringer Ingelheim for generously supplying BHT 920. We are also indebted to Ciba-Geigy Corporation for the gift of terbutaline hydrochloride and phentolamine hydrochloride. The work was supported in part by NIH grant NS 16829. 相似文献
95.
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
96.
C. N. Powell 《Cellular and molecular life sciences : CMLS》1978,34(11):1450-1451
Summary 9 groups of 6 female rats were used in an experiment using fraction 3 ofTrypanosoma rhodesiense. 500 g gave 100% immunoprotection and 1000 and 1500 g gave 66% immunoprotection when challenged with 5×102
T. brucei. 2 groups of 10 female rats were tested for a short period inoculation immune response. In this, 750 g of fraction 3 ofT. rhodesiense gave 70% immunoprotection when challenged withT. brucei.I thank the University of Zambia for support; Dr M. A. Q. Awan, Mazabuka, Zambia, forT. rhodesiense andT. brucei; Prof. J. W. Kibukamusoke, Dr O. Okong'o and Dr W. W. Anokbonggo for advice; Mr L. Nyaliti for technical help. 相似文献
97.
Summary A relatively safe and simple procedure was developed for the induction of hepatomas in the rat by the s.c. administration of powdered 3-methyl-p-dimethylaminoazobenzene. 相似文献
98.
C Torrossian 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(9):693-696
The oxygen consumption of "hibernating" ants shows a grouping effect translated by a significant decrease in the level of oxygen consumption as a function of grouping effect. The general relation between oxygen consumption and the living body mass is the same, if the living material belongs to a single animal, or a social community of ants. 相似文献
99.
Triiodothyronine injected daily to pregnant rats for the last week of gestation (50 microgram/100 g b.wt) increased the specific activities of 5 acid glycosidases in the fetal forebrain and cerebellum. Cortisone (50 mg/100 g b.wt) administered in the same period had no effect on cerebellum acid hydrolases, but decreased their activity in the forebrain. 相似文献
100.
The spontaneous conversion of mammalian cyclic GMP-dependent protein kinase (G-PK) into modulator-dependent protein kinase (type II) (M-PKII) in the absence of cGMP or histone was observed in vitro. The findings, together with similarity in substrate protein specificity, suggest that M-PKII is the catalytic subunit of mammalian G-PK. 相似文献