References of "1971"
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See detailDistribution et âges des Ap et des Am
Renson, Pierre ULg

in Astronomy and Astrophysics (1971), 13

Abstract image available at: http://adsabs.harvard.edu/abs/1971A&A....13..130R

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See detailPenicillin-sensitive DD-carboxypeptidase from Streptomyces strain R 61
Leyh-Bouille, Mélina; Coyette, Jacques; Ghuysen, Jean-Marie ULg et al

in Biochemistry (1971), 10(11), 2163-2170

The D-alanyl-D-alanine carboxypeptidase excreted by the penicillin-sensitive Streptomyces strain R 61 is an anionic protein at pH 6.5. It does not require cations for its action. By comparison with the ... [more ▼]

The D-alanyl-D-alanine carboxypeptidase excreted by the penicillin-sensitive Streptomyces strain R 61 is an anionic protein at pH 6.5. It does not require cations for its action. By comparison with the penicillin-resistant DD-carboxypeptidase from Streptomyces albus G, the penicillin-sensitive R 61 enzyme has high Km values with all the peptides which were used but the alignment of catalytic groups is more effective in promoting hydrolysis of the peptides (high Vmax values). Moreover, the substrate structures required by the two enzymes show some differences. In contrast to the albus G DD -carboxypeptidase which is either not, or very little, affected by penicillins, the R 61 enzyme is inhibited by low dose levels of penicillin G and by cephalothin [less ▲]

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See detailWall peptidoglycan in Aerococcus viridans strains 201 Evans and ATCC 11563 and in Gaffkya homari strain ATCC 10400
Nakel, Marlies; Ghuysen, Jean-Marie ULg; Kandler, Otto

in Biochemistry (1971), 10(11), 2170-2175

The wall peptidoglycans in Gaffkya homari ATCC 10400 and in Aerococcus viridans 201 Evans and ATCC 11563 are made up of peptide units L-alanyl-γ-D-glutamyl-L-lysyl-D-alanine and L-alanyl-D-isoglutaminyl-L ... [more ▼]

The wall peptidoglycans in Gaffkya homari ATCC 10400 and in Aerococcus viridans 201 Evans and ATCC 11563 are made up of peptide units L-alanyl-γ-D-glutamyl-L-lysyl-D-alanine and L-alanyl-D-isoglutaminyl-L-lysyl-D-alanine. The yields of the peptide fragments obtained after enzymatic degradations of the walls are consistent with a peptidoglycan structure in which all the N-acetylmuramic acid residues in the glycan strands are peptide-substituted and in which about half of the peptide units occur as uncross-linked monomers whereas the others form dimers by means of Nє-(D-alanyl)-L-lysine linkages. These walls are the first known examples of lysine-containing peptidoglycans of chemotype I. [less ▲]

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See detailEtude par Spectrométrie de Masse de la formation d'Ions Négatifs par Attachement Electronique Dissociatif et par le processus de Paire d'Ions.
Locht, Robert ULg

Doctoral thesis (1971)

The aim of this work is to investigate the appearance of negative ions by both the mechanism of Dissociative Electron Attachment (DEA) and Ion Pair processes (IPP) by electron impact. Using the ... [more ▼]

The aim of this work is to investigate the appearance of negative ions by both the mechanism of Dissociative Electron Attachment (DEA) and Ion Pair processes (IPP) by electron impact. Using the appropriate instrumentation (a conventional Nier type mass spectrometer) the best conditions are chosen to ensure ion-molecule collision free ion production (sample pressure, impinging electron beam current), the linearity of the electron energy scale between 2 eV and 100 eV and to minimize mass (and translational kinetic energy) discrimination. The used ionizing electron beam allowed us a resolution of 0.5 eV. An ionization model for both processes is proposed to provide us a method for the measurement of the threshold energy of DEA and IPP. Were necessary the numerical derivation of the ion current (for IPP) and the deconvolution of the ionization efficiency curves (for both DEA and IPP) are applied to increase the accuracy of the threshold energy determination and the resolution of the successive ion producing processes to be observed. DEA and IPP’s are observed and threshold energies are measured and assigned in: (i) diatomic molecules, i.e. H2, CO, NO and O2, (ii) triatomic molecules, i.e. CO2 and CS2 along the reaction paths providing O- and S- and CS-. No CO- ion has been detected. (iii) polyatomic molecules, i.e. CH4, C2H2, C2H4, C2H3F and C2H3Cl. Beside the monoatomic negative ions (H-, C-), diatomic and polyatomic negative ions are detected. For several of these species the electron affinity (EA) of the radical is not known, e.g. CH, C2 and C2H. From the appearance of the corresponding negative ions and threshold measurements this fundamental quantity has been deduced. In the particular case of C2-, the production of the negative ion in an electronically excited state has been put forward for the first time. Dissociation energies of the same diatomic and triatomic negative ions have been deduced and compared with this same magnitude in neutral and positive ionic species. [less ▲]

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See detailLa spectroscopie des complexes de transfert de charge peut contribuer à l'interprétation du premier potentiel d'ionisation du donneur (éthylenimine, oxyde d'éthylene, sulfure d'éthylene)
Locht, Robert ULg

Doctoral thesis (1971)

The relationships between the ionization energy (IE) of a donor compound and the position of the UV photoabsorption band of the complex of this donor with iodine as an acceptor are carefully analyzed ... [more ▼]

The relationships between the ionization energy (IE) of a donor compound and the position of the UV photoabsorption band of the complex of this donor with iodine as an acceptor are carefully analyzed. Their specificity with respect to (i) the adiabatic and vertical IE and (ii) the nature of the ionized orbital (n or pi) is examined. This analysis allowed us to attempt to determine the nature of the molecular orbital (MO) involved in the ionization process of ethylenimine, ethylene oxide and ethylene sulfide. Very likely the first IE corresponds to the ionization of the non-bonding (n) orbital located on the N and O atoms. Owing to the closeness of the "n" and "pi" IE for sulfides, in the case of ethylene sulfide no conclusion could be drawn. [less ▲]

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See detailOccurrence of glucomuramic acid in gram-positive bacteria
Wheat, R.-W.; Ghuysen, Jean-Marie ULg

in Journal of Bacteriology (1971), 105(3), 1219-1221

Analyses of 48 gram-positive bacteria indicate only glucomuramic acid and no galactomuramic acid in cell walls.

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See detailPhénomènes de fluorescence dans les astres.
Swings, Polydore ULg

in Mémoires de la Societe Royale des Sciences de Liège (1971), 1

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See detailVolume jubilaire Louis d’Or
Swings, Polydore ULg; Mignolet, Joseph C.-P.

Book published by Société Royale des Sciences de Liège (1971)

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See detailThermal instability and Jeans criterion.
Manfroid, Jean ULg

in Bulletin de la Société Royale des Sciences de Liège (1971), 40

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See detailLettre et phonème à l'âge classique. Avec un essai inédit de Turgot
Droixhe, Daniel ULg

in Lingua (1971), 28

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See detailEtude par spectrométrie Mössbauer de la distribution du fer dans les fractions minéralogiques séparées de roches lunaires rapportées par Apollo 12
Duchesne, Jules; Depireux, Joseph ULg; Gérard, A. et al

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1971), 5e série, v. 4(LVII), 1204-1211

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See detailL'évolution économique de la province de Liège depuis 1960
Merenne-Schoumaker, Bernadette ULg

in La Géographie (1971), (91), 215-234

Analysis of changes in the economy of Liege between 1960 and 1970

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See detailIntoxication oxycarbonée et gaz naturel
Lamy, Maurice ULg; Noirfalise, A.

in Revue Médicale de Liège (1971), 26(4), 128-133

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See detailLa tachycardie au Flaxédil. Action vagolytique ou stimulation des récepteurs béta?
Hanquet, Marcel; Lamy, Maurice ULg; Leruth, P.

in Acta Anaesthesiologica Belgica (1971), 21

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See detailIsolement et structure de nouveaux alcaloïdes extraits du Strychnos usambarensis du Rwanda
Angenot, Luc ULg

in Journal de Pharmacie de Belgique (1971), 26(5), 585-588

We have isolated four new alkaloids from the root bark of Strychnos usambarensis: usambarensine, dihydro-usambarensine and their Nb-methyl quaternary derivatives.

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See detailDe l'existence en Afrique Centrale d'un poison de flèche curarisant, issu du Strychnos usambarensis GILG
Angenot, Luc ULg

in Annales Pharmaceutiques Françaises (1971), 29(5-6), 353-364

During a collecting trip of some medicinal and poisonous plants in Eastern Rwanda, the author observed the use of a hunting poison prepared from Strychnos usambarensis by Banyambo (small tribe living ... [more ▼]

During a collecting trip of some medicinal and poisonous plants in Eastern Rwanda, the author observed the use of a hunting poison prepared from Strychnos usambarensis by Banyambo (small tribe living along Akagera river on the border between Rwanda and Tanzania). He could get the raw poison and arrows from these people. The author has shown the presence of curarizing properties caused by quaternary alkaloids located in barks of Strychnos usambarensis roots. This is an entirely new fact which allows us to assure the existence of a curare in Africa. Indeed BISSET and LEEUWENBERG ( Lloydia, 1968,31, p208-222) reviewed Strychnos sp. used in central Africa as ordeal and arrow poisons and they did not report the use by the natives of a curarizing arrow-poison. [less ▲]

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See detailL’ordinateur dans la didactique des langues anciennes
Denooz, Joseph ULg

in Didactica Classica Gandensia (1971), (11), 83-84

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See detailMass Spectrometric Study of Ion-Pair Processes in Diatomic Molecules: H2, CO, NO and O2.
Locht, Robert ULg; Momigny, Jacques

in International Journal of Mass Spectrometry and Ion Physics (1971), 7

The appearance of ion-pair processes has been studied in H2, CO, NO and O2. The different thresholds have been interpreted. Convolution and deconvolution techniques have been applied to the ionization ... [more ▼]

The appearance of ion-pair processes has been studied in H2, CO, NO and O2. The different thresholds have been interpreted. Convolution and deconvolution techniques have been applied to the ionization efficiency curves to determine (i) a method for the determination of the threshold energy and (ii) the kinetic energy distribution of the fragments. [less ▲]

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