Showing papers by "Hungarian Academy of Sciences published in 1972"
TL;DR: G is s-connected and has no Hamiltonian circuit, but there are s paths starting at x and terminating in C which are pairwise disjoint apart from x and share with C just their terminal vertices.
633 citations
280 citations
TL;DR: A study has made of the effect of (Na+‐K+‐Mg2+)‐activated membrane ATP‐ase inhibitors on the acetylcholine release from the terminals of enteric nerves and from cortical slices.
Abstract: 1. A study has made of the effect of (Na(+)-K(+)-Mg(2+))-activated membrane ATP-ase inhibitors on the acetylcholine release from the terminals of enteric nerves and from cortical slices.2. The resting output of acetylcholine from slices of rat cortex was not affected by tetrodotoxin or by noradrenaline, indicating the lack of propagated activity during rest. Furthermore, there was an output of acetylcholine in the absence of Ca.3. The resting acetylcholine output from cortical slices was increased by (a) addition of ouabain or (b) administration of sodium p-hydroxymercuribenzoate (PHMB), (c) sodium withdrawal and (d) Ca replacement by Ba(+).4. Omission of Ca in the presence of 1 mM ethyleneglycol-bis-(beta-aminoethyl-ether)-N,N'-tetra-acetic acid (EGTA) did not affect the increase of acetylcholine release by the inhibition of (Na(+)-K(+)-Mg(2+))-activated ATP-ase induced by ouabain or by PHMB, but reduced that due to Na removal.5. Ouabain increased acetylcholine release promptly.6. Mg-excess (9.3 mM), noradrenaline and adrenaline were capable of reducing the increase of acetylcholine release from cortical slices evoked by ouabain, PHMB or by Ca replacement by Ba, but not by Na removal.7. A possible role for (Na(+)-K(+)-Mg(2+))-activated ATP-ase in the release of acetylcholine is discussed. It is suggested that the effect of Ca and Mg ions on acetylcholine release might be attributed to their ability to inhibit and activate the membrane ATP-ase, respectively.
193 citations
174 citations
TL;DR: The Pinocytose der Gehirnkapillaren war durch das substitutielle cyclische N6O2-Dibutyrylderivat des 3′,5′-Adenosinmonophosphats signifikant gesteigert as discussed by the authors.
Abstract: Die Anzahl der pinocytotischen und stachligen Vesicula wurde unter normalen Bedingungen mit Bezug auf einheitliche Gebiete der pinocytotischen Aktivitat der Kapillaren von Mausegehirnen quantitativ charakterisiert. Die Pinocytose der Gehirnkapillaren war durch das substitutielle cyclische N6O2-Dibutyrylderivat des 3′,5′-Adenosinmonophosphats signifikant gesteigert.
89 citations
TL;DR: In this paper, the authors studied the nucleation rate and the rate of crystal growth in a-Ge films, paying particular attention to the effects of residual gases, and the activation energies for the relevant processes were obtained.
Abstract: The authors studied the nucleation rate and the rate of crystal growth in a-Ge films, paying particular attention to the effects of residual gases. Activation energies for the relevant processes were obtained.
88 citations
TL;DR: The soluble fraction inhibits and the catecholamines stimulate both the ouabain sensitive and insensitive parts of the total ATPase activity, which may occur as a reaction to the inhibition.
75 citations
60 citations
TL;DR: Perturbation difference spectra measurements in 20% polyethylene glycol indicated that one tryptophyl side chain per mol amylase was involved in the interaction with maltose, and it is assumed that the tryptophile side chain interacting with Maltose may be involved inThe binding of substrate by pancreatic amyl enzyme.
Abstract: 1
The effect of maltose was studied in porcine pancreatic amylase. At neutral pH 1% (29 mM) maltose produced with amylase a difference spectrum characteristic of the perturbation of tryptophan. The molar absorption difference at the maximum wavelength was Δ290= 1200.
2
The difference spectrum appeared to be specific for maltose. Perturbation difference spectra measurements in 20% polyethylene glycol indicated that one tryptophyl side chain per mol amylase was involved in the interaction with maltose.
3
The dissociation constant of the amylase · maltose complex calculated from the concentration dependence of the absorption difference at 290 nm was Ks= 13 mM. Maltose inhibited amylase activity competitively and an inhibition constant of Ki= 25 mM was obtained, a similar value to that found spectrophotometrically. It is assumed that the tryptophyl side chain interacting with maltose may be involved in the binding of substrate by pancreatic amylase.
54 citations
TL;DR: Carotenoid composition in leaves of normal, lycopenic and ζ-carotenic mutants of Zea mays were investigated, finding that under high intensity illumination, carotenoids were rapidly destroyed.
46 citations
TL;DR: The incidence of cleft lip with or without cleft palate was studied in relatives of Hungarian index patients and found to be 4.86% in sibs, 0.75% in uncles/aunts and 0.31% in first cousins.
Abstract: The incidence of cleft lip with or without cleft palate was studied in relatives of Hungarian index patients and found to be 4.86% in sibs, 0.75% in uncles/aunts and 0.31% in first cousins. Relating t
Journal Article•
TL;DR: In excised Avena leaves, kinetin and benzyladenine decreased, while abscisic acid and benzimidazole increased the over-all nuclease level, and the level of an alkaline phosphodiesterase, an exo-nuclease, was not affected by any of the growth regulators tested.
Abstract: In excised Avena leaves, kinetin and benzyladenine decreased, while abscisic acid and benzimidazole increased the over-all nuclease level. Significant effects were observed as early as 2 h after treatment. Not all the nucleases of the Avena leaf were affected by the growth regulators. Changes in over-all nuclease activity were accounted for almost entirely by changes in the amount of a relatively purine-specific endo-ribonuclease, which produces 2', 3'-cyclic phosphates as breakdown products. Slight changes induced by the growth regulators were also detected in the amount of a sugar non-specific endo-nuclease which produces 5'-nucleotides and has a relative specificity for adenylic acid. The level of an alkaline phosphodiesterase, an exo-nuclease which produces 5'-nucleotides, was not affected by any of the growth regulators tested. Gibberellic acid and indol-3yl-acetic acid did not influence the level of Avena nucleases.
TL;DR: The potential and concentration dependence of oxalic acid adsorption has been investigated on platinized Pt electrodes in 1 M HClO 4 supporting electrolyte by a tracer method as discussed by the authors.
TL;DR: In this article, the authors gave a weaker condition guaranteeing the same maximum of the size of the largest binomial coefficients of order n. This condition was formulated in more abstract language.
TL;DR: In this paper, Sinfelt and Taylor showed that the initial step for hydrogenolysis is probably common and the adsorption with CC bond rupture may be ruled out in comparison with methane-deuterium exchange under the same condition.
TL;DR: In this paper, the corresponding dinuclear carboxylato rhodium carbonyls were converted by an excess of the ligand into the mononuclear Rh(CO)(PPh 3 ) 2 (OOCR) 2 (R Me, Et).
TL;DR: In this paper, a least-squares computational method is used to determine by computer the constants to account for all the experimental variables, and the equation expressing the temperature-dependence of the retention index has a shorter or longer linear portion depending on the natures of the substances involved and the stationary phase in the temperature range generally used in gas-liquid chromatography.
TL;DR: The increase in nuclease activity in ‘Xanthi’ tobacco leaves infected with tobacco mosaic virus was found to be due mainly, if not entirely, to an increase in the level of a relatively purine (guanine) specific endoribonuclease.
TL;DR: Citrate lyase from Klebsiella aerogenes inactivated by reaction in the presence of substrate or by treatment with hydroxylamine can be reactivated with acetic anhydride only if its sulfhydryl groups are reduced.
Abstract: Citrate lyase from Klebsiella aerogenes inactivated by reaction in the presence of substrate or by treatment with hydroxylamine can be reactivated with acetic anhydride only if its sulfhydryl groups are reduced. Alkaline hydrolysis of pure citrate lyase yields about 3 mol of phosphopantothenate per mol of enzyme.
TL;DR: In this article, the results of pyrolysis-gas chromatographic experiments performed either with dimethyl-poly-siloxanes of different molecular weight terminated with −OH, −OR, −OK and −OSiMe3 groups, or with poly-dimethyl-sil-ethylene-siloxane and polydimethyl polysiloxane samples respectively, were utilized for the evaluation of the thermal degradation mechanism of these polymers.
Abstract: The investigated linear polymers consisted partly of dimethyl-siloxane units-[Me2SiO]n-and partly of regularly alternating tetramethyl-disiloxane and short hydrocarbon chain segments. The results of pyrolysis-gas chromatographic experiments performed either with dimethyl-poly-siloxanes of different molecular weight terminated with −OH, −OR, −OK and −OSiMe3 groups, or with poly-dimethyl-sil-ethylene-siloxane and poly-dimethyl-sil-propylene-siloxane samples respectively, were utilized for the evaluation of the thermal degradation mechanism of these polymers. All the significant peaks on the pyrograms were identified and the relative amounts of the pyrolysis products were estimated at different pyrolysis temperatures. Based on present experimental results, decomposition of the polydimethyl-siloxanes may proceed on two different ways. In the presence of catalytic amounts of potassium ions the heterolytic cleavage of the silicon-oxygen bond is initiated at the polymer chain terminals, resulting in the formation of rings consisting of 3–8 dimethyl-siloxane units. Noncatalyzed thermal degradation, however, is not affected by the terminal groups. The main degradation product, the hexamethyl-cyclo-trisiloxane is formed via a fourcentered intramolecular transition complex, arising from spiralization of the polymer chain. The poly-dimethylsil-alkylene-siloxanes may also decompose by this latter (siloxane-type) degradation, yielding cyclic monmers of the
type. Nevertheless, a competing reaction, namely radical-type splitting of the C−C or Si−C bond in the hydrocarbon segment of the polymer chain, followed by an intermolecular radical transfer and subsequent β-scission takes place simultaneously. We observed, that the reproducibility of relative amounts of the components on the pyrograms was fairly good on comparison of products of the same decomposition path-way, but was poor if decomposition products of different competitive reactions were related.
TL;DR: In this article, the symmetric group of n letters was considered and the properties of certain complexes of a large group which are shared by most of these complexes were studied. But the properties were not discussed.
Abstract: 1. By statistical group-theory we mean the study of those properties of certain complexes of a “large” group which are shared by “most” of these complexes. The group considered in this paper will be &, the symmetric group of n letters; its group-elements will be denoted by P. The complexes considered here will be simply the elements P of 8, ; the property in question will be the group-order O(P) of P. As to this LANDAU proved (see [a]) for
TL;DR: In this paper, a preparation method for the electrochemical oxidation of primary alcohols was proposed, illustrated in detail on the example of di-isopropilidene-sorbose oxidation.
TL;DR: The purpose of the investigations was to study the dissociation of tetrameric D-glyceraldehyde3phosphate dehydrogenase under conditions compatible with enzyme action and has succeeded in detecting the Dissociation of the enzyme both into dimers and monomers on dilution.
TL;DR: In this paper, the thermal track fading effect has been studied in various plastic track detectors irradiated with lightly and heavily ionizing nuclear particles and the possibilities of the eradication of alpha-particle background and the selective thermal track discrimination in cellulose nitrate, cellulose acetate and polycarbonate detectors have been studied.
Abstract: Thermal effects can alter the physical and chemical parameters of the latent tracks and bulk material of dielectric track recorders, consequently those of the etched track pits too. A few characteristics of this thermal track-fading effect have been studied in various plastic track detectors irradiated with lightly and heavily ionizing nuclear particles. Experimental data are given for the influence of different annealing conditions on the diameter of etch pits and the bulk etch rate of plastics. The possibilities of the eradication of alpha-particle background and the selective thermal track discrimination in cellulose nitrate, cellulose acetate and polycarbonate detectors have been studied. Few practical applications of the thermal track fading are also presented.