Browsing by Issue Date Artículos de revistas
Now showing items 61-80 of 4968
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(Pergamon Press, 1974-02-20)The known alkaloids zizyphine-A (1) and -B (2), abyssinine-A (4) and -B (5), and the previously undescribed zizyphine-C (3), -D (6) and -E (7) have been isolated from the stem bark of Zizyphus oenoplia. The structures ...
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(Laboratorios Mixim S.A., 1974-09-25)The leaves and bark of Cryptocarya alba (Mo\.) Looser (Lauraceae) were examined for alkaloida, and found to contaín a single basic component, whích was isolated and shown to be (+)-reticuline(l). This substance was ...
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(ASOCIACION QUIMICA ARGENTINA, 1975)Fagara mayu leaves yield four furanocoumarins, identified as psoralen (1), bergapten (11), xanthotoxin (111), and isopimpinellin (IV). The occurrence of these compounds together with furanoquinolines and canthinone, and ...
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(Springer-Verlag, 1975)The time course of the membrane currents in the node of Ranvier in which the sodium and potassium conductances have been blocked reveals asymmetries during and after the application of depolarizing and hyperpolarizing ...
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(1975)THE microinjection technique perfected by Gurdon and his collaborators 1,2 represents an excellent method for the study of the in vivo effects of drastically changing the molecular contents of the injected cells. We have ...
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(1975)It is shown that the energy-momentum tensor of the electromagnetic field, for an electron in a curved space, may be split into two dynamically independent parts. One of them, the radiation tensor, has the following remarkable ...
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(1975)When hemocyanin is added to a black lipid film, the conductance increases in discrete steps. For negative potentials the single step conductance is constant, but for positive potentials the step conductance appears to ...
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(1975)Coriolis coupling constants and the inertia defect for cis- and trans-1,2-dichloroethylene have been calculated, using force constants obtained by the iterative consistency method. The results obtained are compared with ...
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(1975)
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(1975)Increasing concentrations of chloride were found to increase the resolution between two visible absorbance spectral transitions associated with acidification of ferricytochrome c. Analysis of a variety of spectral and ...
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(1976)We show the extent to which Lorentz-Dirac equations of motion for the electron follow from Maxwell's equations. The standard derivations depend on cutoff procedures and other prescriptions. The conclusion is that the Lorentz ...
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Aromatic nucleophilic substitution in nucleophilic surfactants. Comparison with alkoxide reactions (1976)The reactions of 2,4-dinitrochloro- and fluorobenzene (DNC and DNF) with the alkoxide ions of choline, propargyl alcohol, and 2,2,2-trifluoroethanol give ether intermediates which react readily with hydroxide ion. The ...
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(1976)The endogenous protein synthesis of Xenopus laevis and Calyptocephalella caudiverbera oocytes was studied by measuring the incorporation into acid-precipitable material of radioactive amino acids placed in the extracellular ...
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(1976)Functional micelles of hexadecyl(2-hydroxyethyl)dimethylammonium bromide (I) are better catalysts than hexadecyltrimethylammonium bromide (CTABr) for the alkaline hydrolysis of diethyl and di-n-hexyl p-nitrophenyl phosphate ...
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Role of glucose-1-phosphate and glucose-6-phosphate in glycogen synthesis by pigeon liver homogenate (1976)1. 1. Glucose-1-C14, G-6-P-1-C14 and G-1-P-l-C14 have been incubated with a pigeon liver homogenate. Incorporation of C14 into glycogen and CO2 were measured. 2. 2. The relative incorporation of C14 from G-6-P-1-C14 and ...
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(1976)We give noncanonical (without string) and canonical (with string) Hamiltonian formulations for a system of classical electric and magnetic charges. We do not introduce potentials in either case. This allows us to see very ...
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(1976)A past history of idiopathic cholestasis of pregnancy (ICP) was detected in 10 out of the 32 multiparous women in the last two generations of a large kindred. The affected women are distributed in five family units, sharing ...