Showing papers by "University of Bordeaux published in 1977"
TL;DR: Chez les lapins infestes avec un clone different, le premier variant qui se developpe appartient toujours au type BoTat-1 qui doit etre considere comme le type de base de the souche.
160 citations
TL;DR: Anatomical controls by using the Fink-Heimer silver impregnating method have demonstrated that the 6-OHDA injections did not destroy fibers other than catecholaminergic and secondly, that the degenerations are found in the forebrain and cortical limbic A10 projections.
107 citations
TL;DR: It is concluded that haemorrhage is a potent stimulus for AVP liberation in the monkey, however, in contrast to some other species, the fall in arterial pressure seems to be the prime stimulus rather than hypovolemia per se.
Abstract: Using unanaesthetized monkeys, experiments were performed to examine the effects of haemorrhage on the liberation of arginine vasopressin (AVP). Haemorrhages of 10%, 15% or 20% total blood volume were performed via a catheter with its tip in the abdominal vena cava. A catheter in the left internal jugular vein was used for blood sampling. Arterial blood pressure was monitored via a catheter whose tip resected in an iliac artery. The monkeys showed no signs of discomfort from this catheterisation. Blood samples for AVP assay were taken at different times from 0-90 min after the end of the haemorrhage. At the end of the experiment, blood removed was reinfused. Results show that haemorrhage resulted in liberation of AVP, but only if there was a fall in arterial blood pressure. AVP release occurred more readily as the total volume of blood withdrawn increased, but the absolute rise in hormone concentration was not related to the total volume of blood withdrawn. However, comparing the area under the curve of mean arterial blood pressure with that for AVP concentration showed the two to have a significant exponential relationship. It is concluded that, as in other species, haemorrhage is a potent stimulus for AVP liberation in the monkey. However, in contrast to some other species, the fall in arterial pressure seems to be the prime stimulus rather than hypovolemia per se.
83 citations
TL;DR: The enzyme is a typical laccase but has an exceptionally low pI and great stability to acid pH and on gel electrophoresis two isoenzymes could be detected.
78 citations
TL;DR: In this article, a defect model for the perovskite AnMnO3n−1 (n ⩾ 2) was proposed for the Ca2Ti2−2xFe2xO6−x solid solution.
72 citations
TL;DR: The results suggest that the more active acetylcholine synthesizing enzyme in the hippocampus of BALB/c may be related to a greater acetyl cholinergic availability, thus favoring the establishment of a long-term memory, perhaps by releasing greater amounts of acetylCholine inThe hippocampus immmediately after the learning session.
71 citations
TL;DR: The crystal structure of V 0.985 Al 0.015 O 2 has been refined from single-crystal X-ray data at four temperatures as mentioned in this paper, and at 373°K it has the tetragonal rutile structure.
67 citations
TL;DR: In this article, a new and unsual transition is reported in Ba 2 NaNb 5 O 15, which was previously known to undergo at 573 K a ferroelastic transition 4 mm → mm 2 (C 4 v → C 2 v ), reverts back at 110 ± 5 K to a low temperature phase of 4 mm ( C 4 v ) symmetry.
53 citations
TL;DR: In this article, the low frequency (0 to 500 cm−1) Raman spectra were recorded at different temperatures between 40 and 413 K through the different structural modifications: P21/c P42/ncm Cmca I4/mmm.
Abstract: The low-frequency (0 to 500 cm−1) Raman spectra are recorded at different temperatures between 40 and 413 K through the different structural modifications: P21/c P42/ncm Cmca I4/mmm. The results agree with previous NMR data and show that the three higher-temperature tetragonal and orthorhombic phases exhibit specific disorder with respect to the orientation of the methylammonium cation while the monoclinic low-temperature modification is ordered. A soft-mode behaviour is observed in the intermediate P42/ncm and Cmca phases, associated with the high-temperature second-order Cmca I4/mmm transition. A discussion of the unusual phase sequence in these materials is tentatively given, in view of previously proposed mechanisms for the phase transitions.
Les spectres Raman de basse frequence (0 a 500 cm−1) ont ete enregistres a differentes temperatures comprises entre 40 et 413 K, dans les differentes phases cristallines: P21/c P42/ncm Cmca I4/mmm. Les resultats sont en accord avec des donnees RMN anterieures et montrent que les trois phases de plus haute temperature (tetragonales et orthorhombique) presentent un desordre specifique dans l'orientation des cations methylammonium, alors que la phase monoclinique de basse temperature est ordonnee. Un comportement de mode mou est associe a la transition du 2e ordre Cmca I4/mmm de haute temperature observe dans les phases inter-mediaires P42/ncm et Cmca. Une discussion de la sequence de phase inhabituelle de ces materiaux est faite sur la base des mecanismes de transitions de phase proposes anterieurement.
51 citations
TL;DR: The specificity of lysis suggests that prior contact with antigen induces a tolerance in sipunculid worms, and cytotoxicity could be specifically reduced following several injections of target cells in vivo.
Abstract: A natural cytotoxic reaction, analogous to that known in rodents, is described in sipunculid worms (coelomata invertebrates). A cytotoxic effect always occured when killer leukocytes reacted on xenogenic erythrocytes. A cytotoxic activity on allogenic erythrocytes occured in all cases when donors of leukocytes and donors of erythrocytes arose from remote stations. Between stations near each other (6 km apart), a cytotoxic effect was noticed in only one case out of three. No allogenic reaction was noticed between Sipunculus nudus from the same station but it occured in one case out of two between Siphonosoma arcassonense from the same station. Cytotoxicity could be specifically reduced following several injections of target cells in vivo . The specificity of lysis suggests that prior contact with antigen induces a tolerance in sipunculid worms.
47 citations
TL;DR: In this article, the existence of a so-called NAC Lifshitz's point in mixtures of two liquid crystals was shown to be a result of enthalpic measurements and some qualitative comparisons with a recent NAC A-smectic C model.
TL;DR: In this article, the binary and ternary lamellar compounds with alkali metals, which are electron donors, and with halogens, electron acceptors, are reviewed, and the following physical properties of crystal compounds of graphite are analysed: 1. (a) transport properties: increase of electrical conductivity and metallic behavior; 2. (b) magnetism: the static measurements show a fundamental difference between the donor compounds which are paramagnetic, and diamagnetic acceptor compounds.
01 Jun 1977
TL;DR: In this article, the exact position of coronene molecules in an n-heptane single crystal exhibiting Shpol'skii effect was determined using X-ray diffraction and ESR analysis.
Abstract: In order to determine the exact position of coronene molecules in an n-heptane single crystal exhibiting Shpol'skii effect, two crucial experimentas were performed: X-ray diffraction study of host n-heptane and ESR investigation of guest coronene. The X-ray experiments were carried out at 100 K; from calculations with an R value of 8% it is found that n-heptane crystallizes in a centered triclinic P 1 system. The resonance fields of the Δm = ± 1 transitions of triplet coronene were measured at 77 K as a function of the orientation of the single crystal in the cavity. Those two experiments demonstrate that the coronene molecules occupy mainly substitutional sites in the n-heptane lattice by replacing three alkane chains in the plane including the c axis.
TL;DR: In this paper, new anionic electrolytes of formulation MBiF4 (M K, Rb, Tl) have been prepared, which have a conductivity of the same order of magnitude than β-alumina.
TL;DR: In this article, the phases of the phase SrLnMnO4 (Ln = La, Nd, Sm, Gd), BaLnNmO4(Ln= La, nd) and M1+xLa1−xmnO 4 (M = Sr: 0⩽ x ⩽ 1; M = Ba: 0.50) have a K2NiF4-type structure and the c a ratio of unit cell is related to the electronic configuration of the Mn3+ ions.
TL;DR: The results of amino acid and carbohydrate analysis of several clone specific glycoproteins of TV.
TL;DR: In this paper, a family of carbon felt-carbon matrix composites with a resistor-graphite furnace working between 1000 and 1300°C was used for the isothermal process.
TL;DR: Proteins of cytoplasmic ribosomes of the Podospora anserina were analyzed by two dimentional gel electrophoresis and the L21 protein of the large subunit was found to migrate differently in a cycloheximide resistant mutant.
Abstract: Proteins of cytoplasmic ribosomes of the Podospora anserina were analyzed by two dimensional gel electrophoresis. The numbers of proteins were estimated to be 28 in the small subunit and 41 in the large subunit. The L21 protein of the large subunit was found to migrate differently in a cycloheximide resistant mutant.
TL;DR: The crystal structure of α-AlB 12, reported recently by Higashi, Sakurai, and Atoda, was confirmed by an independent investigation of a different crystal as discussed by the authors.
TL;DR: In this article, the evolution of electrical properties as a function of composition has been discussed in terms of structure and chemical bonding in Li4B7O12X-Li2O systems at 750°C.
TL;DR: In this paper, a new ferrite of formula Ca/sub 2/LaFe/sub 3/O/sub 8/ has been isolated and its structural model has been tested by Moessbauer spectroscopy and magnetic measurements.
TL;DR: The widely accepted idea that alkanes found in mammalian tissues are almost certainly exogenous is supported, although an alternative possibility is that these very long, aliphatic chains are synthesized in situ by the animal cells, although this last hypothesis is just speculative.
TL;DR: Alkanes, a new class of neurolipid, were found in mouse brain, the level being reduced in the Quaking mutant, and the distribution pattern was determined by gas liquid chromatography and was found to differ in normal and Quaking myelin.
Abstract: —
Alkanes, a new class of neurolipid, were found in mouse brain, the level being reduced in the Quaking mutant. These hydrocarbons are concentrated in myelin; minor amounts being found in microsomes, mitochondria and synaptosomes. The average recovery is 7.1 μg/mg in normal myelin, 2.2 in the Quaking myelin. The distribution pattern of these alkanes was determined by gas liquid chromatography and was found to differ in normal and Quaking myelin; the hydrocarbons consist mainly of n-alkanes ranging from C21 to C32 with even and odd aliphatic chains.
TL;DR: In this paper, the magnetic properties of RbVCl3, CsVCl 3, csVBr3, and CsVI3 have been investigated in the temperature range 4.2-800°K.
TL;DR: The structure of azole organotin compounds depends on the position of the nitrogen atoms in the aromatic ring as mentioned in this paper, with at least two nitrogens in the 1-3 position in the ring giving the corresponding organotin derivatives which have a polymeric structure.
TL;DR: Treatment of yeast mitochondria with digitonin was used in order to prepare an inner membrane-matrix fraction preserving its permeability properties, and these new organelles retained respiratory control when assayed with ethanol as the substrate.
TL;DR: The demonstration of a functional interdependence among the three mod genes suggested that modC is not the structural gene for the protease associated with cell lysis, but is involved, like modA and modB, in its control.
Abstract: In Podospora anserina, protoplasmic incompatibility (a phenomenon that prevents heterokaryon formation because of the destruction of the fused cells) can be studied in homokaryotic strains that combine nonallelic incompatibility genes or carry mutations at the lys loci. In these strains cell destruction occurs early in development and is associated with an arrest of growth.-From the self-lysing strains lysA(1) and RV (R and V are nonallelic incompatibility genes) mutations have been selected that suppress the self-lysing trait, i.e., that prevent cell destruction and remove growth inhibition. Some of them were derived from a novel modifier locus, modC, located near the mating-type locus.-In C/D and C/E incompatibility systems, modC mutations, which per se have no obvious effect, were considered in addition to mutations in the previously identified modifier loci, modA and modB. The demonstration of a functional interdependence among the three mod genes suggested that modC is not the structural gene for the protease associated with cell lysis, but is involved, like modA and modB, in its control.-All three modC mutant strains investigated exhibit defects in the formation of protoperithecia, suggesting that the modC gene function is essential to the occurrence or development of the female organs. This is the third argument that supports the hypothesis ( Boucherie, Begueret and Bernet 1976) that protoplasmic incompatibility and female organ formation might be related phenomena.
TL;DR: The analysis of allowed electronic transitions in thin films of the disordered ionic compounds MgF(2) and AIF(3) was obtained by optical absorption studies in the uv region by means of Rutherford backscattering and alpha-X reactions.
Abstract: The analysis of allowed electronic transitions in thin films of the disordered ionic compounds MgF2 and AlF3 was obtained by optical absorption studies in the uv region. The results are given as a function of the composition and of the degree of crystallization of the films. The characterization of the samples resulting from nuclear analysis (Rutherford backscattering and α–X reactions), intramolecular vibrations (ir absorption), and x-ray diffraction studies are reported.
TL;DR: In this article, the reaction order of trimethylsilyl chlorosulphonate of various substituted silicon compounds is found to be: allyl > α-naphthyl > phenyl > vinyl.