Showing papers by "Paul Sabatier University published in 1978"
TL;DR: It is demonstrated that the loss of “H2O” below 200°C is reversible and causes no significant change in the lattice parameter of these apatites, whereas loss of H2O between 200° and 400°C are irreversible and causes a contraction in the α-axis dimension.
Abstract: Types of “H2O” in human enamel and in precipitated apatites are characterized using X-ray diffraction, infrared (IR) absorption spectroscopic and thermogravimetric analyses. Changes in lattice parameters (principally in the α-axis dimensions) and in the character of the IR absorption bands are correlated with weight losses at pyrolysis temperatures of 100° to 400°C and with effect of rehydration and reignition of previously ignited samples.
241 citations
TL;DR: In this article, the oxidation of magnetite yields the lacunar phase γ-Fe 2 O 3, for sizes less than 5000 A, and the rhombohedral phase, α-Fe 3 O 3 for sizes above 10 000 A.
67 citations
TL;DR: In this article, a comparison of Auger structures observed on the energy distributions of secondary electrons emitted from Mg and A1 solid targets bombarded by either light particles (H + and He + ) or heavy ions (Ne +, Ar +, …) is presented.
58 citations
TL;DR: In this paper, the ISEE Mother/Daughter dual spacecraft system was used to study particle phenomena in the Earth's outer magnetosphere and beyond, using large geometric factor fixed voltage electrostatic analyzers and passively cooled semiconductor detector telescopes.
Abstract: This experiment is designed to take advantage of the ISEE Mother/Daughter dual spacecraft system to study energetic particle phenomena in the Earth's outer magnetosphere and beyond. Large geometric factor fixed voltage electrostatic analyzers and passively cooled semiconductor detector telescopes provide high time resolution coverage of the energy range from ~1.5 to 300 keV for both ions and electrons. Essentially identical instrumentation is placed on the two spacecraft to separate temporal from spatial effects in the observed particle phenomena.
57 citations
TL;DR: Data support the views that phenolic compounds have a role in enhanced resistance of the tomato plant to Fusarium; treatment with phenol precursors could provide a convenient model to study the mechanisms of resistance involved.
Abstract: Treatment of susceptible tomato plants with quinic acid increased both their phenolic content (soluble phenols-lignin) and their resistance to Fusarium oxysporum. The same results were obtained with phenylalanine, but other compounds, unrelated to phenolilis, were ineffective. Quinic acid showed no fungitoxic effect by itself. The degree of resistance was positively correlated with the induced phenolic level and plants with a stimulated phenolic pool contained less mycelium than control plants. These data support the views that phenolic compounds have a role in enhanced resistance of the tomato plant to Fusarium; treatment with phenol precursors could provide a convenient model to study the mechanisms of resistance involved.
49 citations
17 Jul 1978
46 citations
TL;DR: The surface mucous cells, mucous neck cells, oxyntic cells and endocrine cells are described, which contain a cytoplasmic “tubulovesicular system”, many large zymogen granules and a rich rough endoplasmic reticulum in the basal cy toplasm.
Abstract: A description of the cytology of the gastric mucosa of the perch has been made. Cytological and cytochemical features of the surface mucous cells, mucous neck cells, oxyntic cells and endocrine cells are described. The surface mucous cells are identified by their location and by the characteristics of their secretory granules. A proportion of these granules contain a core with electron density different from the rest of the granule. These granules, except for the electron-dense core, react cytochemically as glycoprotein. The mucous neck cells are distinguished by their shape, the appearance of their mucous granules and their location between surface mucous cells and glandular cells. The oxyntic cells contain a cytoplasmic “tubulovesicular system”, many large zymogen granules and a rich rough endoplasmic reticulum in the basal cytoplasm. Endocrine cells extending up to the gastric lumen were also observed.
45 citations
TL;DR: The ARAKS experiment has produced many results which are not yet well understood as discussed by the authors, and the injection of an electron beam into the magnetosphere has been considered a straightforward technique for studying the large-scale structure of the Earth's environment.
Abstract: The injection of an electron beam into the magnetosphere has been considered a straightforward technique for studying the large-scale structure of the Earth's environment. The large current released in the magnetosphere by the ARAKS experiment has produced many results which are not yet well understood.
44 citations
TL;DR: The pyridoxine molecule acts as a bidentate ligand through two oxygen atoms and as a bridge between two equivalent atoms in an octahedral environment.
33 citations
TL;DR: In this article, the carbon-13 chemical shifts and the 1J(CH) coupling constants for 18 azolium salts (di-N-methyl-pyrazolium, -indazolium and -benzimidazolate ionides) have been determined and assigned.
Abstract: The carbon-13 chemical shifts and the 1J(CH) coupling constants for 18 azolium salts (di-N-methyl-pyrazolium, -indazolium, -benzimidazolium and -benzotriazolium iodides) have been determined and assigned. The chemical shifts are discussed as a function of substituent effects, positive charge introduction and total electronic density (calculated by the CNDO/2 method). The general problem of correlations between chemical shifts and total charge densities in azoles is discussed. A statistical approach shows that these correlations are of poor quality.
31 citations
TL;DR: In this paper, the potential curves of the lowest excimer states of Ar 2 were determined by a SCF calculation using a non-empirical atomic pseudopotential proposed by Durand and Barthelat.
TL;DR: In this paper, the PSIBMOL algorithm was used for pseudo-potential calculations on the molecules ScH3, TiH3F, MnO4 -, Zn(CH3)2 and Pd(CO)4.
Abstract: Our non-empirical pseudo-potential method is tested on the molecules ScH3, TiH3F, MnO4 -, Zn(CH3)2 and Pd(CO)4. The calculations are performed with the PSIBMOL algorithm, described in paper I (Mole...
TL;DR: In this article, the influence determinante du silicium and du germanium en ene-synthese a ete confirmee en confrontant des sila et germa-1 cyclopentenes-3 and des allenylsilanes a PhSO 2 NSO, nouvel enophile hautement reactif.
TL;DR: These observations prove that gynogenetic Urodeles can be produced in large numbers and confirm the possibilité ofobtenir en grand nombre des individus gynogénétiques viables chez les Urodèles.
Abstract: Eggs of diploid females of Pleurodeles waltlii, inseminated by genetically inactivated sperm of Salamandra salamandra, have been treated by heatshock or increased hydrostatic pressure during the first hour of their development. The resulting viable gynogenetic individuals show different degrees of ploidy although they mostly are diploid. The use of females with a pericentric inversion as a marker chromosome allow the chromosomal constitution to be clarified. Eggs of females heterozygous for a recessive semilethal mutation (ascite caudale, ac) subjected to the same experimental treatment gave 50% ac/ac embryos. Experiments with Pleurodeles poireti gave the same results as those with P. waltlii. These observations prove that gynogenetic Urodeles can be produced in large numbers. In their offspring the detection of inherent or spontaneous recessive mutations is greatly facilitated.
TL;DR: In this paper, a number of 1-substituted 1,2-dimethylsilacyclopentanes are described, and a discussion of the role of ring strain in determining stereochemical outcome and reaction rates is presented.
TL;DR: Structural studies by chemical degradation and mass spectrometry allow one to propose structure Ic for this compound, namely 6-(2-tetradecyl 3-keto octadecanoyl)-alpha-D-trehalose, and this structure was confirmed by chemical synthesis.
TL;DR: Am industriell hergestellten Kompost soll die M6glichkeit einer Trennung yon mehreren polycyclischen Aromaten mit dem Ziel der quantitativen Bestimmtmg dieser Cancerogene aufgezeigt werden.
TL;DR: In this article, le phytoplancton de la riviere Lot has been identified as a major source of photosynthese, and le photosynthetique par unite de surface (Σ A) is fonction de l'extinction de the lumiere (α) and du logarithme du quotient energie lumineuse incidente/intensite du debut de saturation de la photosynthesse par la lumiere.
Abstract: 1) Pres de 190 especes d'algues ont ete identifiees dans le phytoplancton de la riviere Lot ; les Diatomees et les Chlorophycees dominent.2) Les plus fortes biomasses (5 a 15 g de poids frais par m3 ) apparaissent dans les grands reservoirs de l'amont et dans la zone canalisee de la partie inferieure de la riviere lors de l'etiage estival. Aux tres faibles debits sont associees des proliferations de Chlorophycees et une stratification verticale.3) L'analyse des profils de photosynthese, mesuree a l'aide de 14 C, montre que la production photosynthetique par unite de surface (Σ A) est fonction de la capacite photosynthetique du phytoplancton (Pmax), de l'extinction de la lumiere (α) et du logarithme du quotient energie lumineuse incidente/intensite du debut de saturation de la photosynthese par la lumiere (I'o/Ik). Pmax semble etre determine par l'abondance des Chlorophycees nanoplanctoniques, elle-meme liee a l'augmentation des temperatures et a la diminution du debit. Les variations de α suivent celles de l'abondance des matieres en suspension ou les algues n'interviennent que pour une faible proportion.4) La production primaire du Lot moyen et inferieur a ete estimee a 275 g C/m2 /an dont pres de 80 % correspond aux trois mois d'ete.5) L'etude d'une masse d'eau au cours de son deplacement montre qu'une grande part (80 %) du carbone assimile est perdue par respiration. Cette respiration represente moins de la moitie de l'oxygene consomme. La production extracellulaire est importante en ete.
TL;DR: In this article, the Riou-Mort draine le bassin houiller de Decazeville, region fortement industrialisee dont il recoit les eaux usees, and ses affluents sont severement pollues en aval des principaux centres industriels par les effluents de diverses usines dont une fonderie de zinc.
Abstract: Le Riou-Mort draine le bassin houiller de Decazeville, region fortement industrialisee dont il recoit les eaux usees. La chimie et les algues benthiques ont ete etudiees dans 14 stations sur le Riou-Mort et ses affluents ainsi que dans 7 stations sur la riviere Lot. Le Riou-Mort et ses affluents sont severement pollues en aval des principaux centres industriels par les effluents de diverses usines dont une fonderie de zinc. Les principaux polluants sont des solides en suspension, du zinc, du cadmium, du cuivre, de l'acide sulfurique et du manganese. La riviere Lot transporte des teneurs elevees de zinc et de cadmium en aval du confluent du Riou-Mort ; les teneurs en zinc persistent au moins 40 km vers l'aval. La flore d'algues benthiques change de facon marquee au niveau des sources de pollution. Pour une pollution "moderee" par les metaux lourds, les communautes de l'amont, dominees par Cladophora glomerata, Ulothrix zonata, Vaucheria sp., Melosira varians et Synedra ulna sont remplacees, en aval, par des communautes dominees par Stigeoclonium tenue, Gongrosira incrustans, Gomphonema parvulum et Surirella ovata. Pour une pollution extreme par metaux lourds, aucune espece d'algue ne subsiste en certaines stations tandis qu'en d'autres, la flore est reduite a deux especes : Gomphonema parvulum et Achnanthes minutissima. Les effets les plus severes sur les algues benthiques sont produits par de fortes concentrations en solides en suspension combinees a de fortes teneurs en zinc et en cadmium.
TL;DR: Control of these activities by androgens and the rete testis fluid appreciated and the highest 5α-reductase enzyme activity was found in the caput, the lowest in the corpus epididymidis.
TL;DR: The corticosteroid-binding globulin content has been determined in cytosols prepared from human endometrium taken at different phases of the menstrual cycle, at 8-10 weeks gestation, and during treatment with an oral contraceptive and it was observed that CBG is a constant contaminant of the endometrial cytosol.
Abstract: The corticosteroid-binding globulin (CBG) content has been determined in cytosols prepared from human endometrium taken at different phases of the menstrual cycle, at 8–10 weeks gestation, and during treatment with an oral contraceptive. The data were compared to the progesterone “receptor” and the progesterone concentration in the same tissue extracts. The plasma contamination was estimated by the serum albumin content. It was observed that CBG is a constant contaminant of the endometrial cytosols. All of the CBG content can be considered to be of plasma origin. The cytoplasmic progesterone “receptor” content is between 21–33% of the CBG concentration during the menstrual cycle and is only 1% during pregnancy. The cytosol progesterone concentration is much higher in endometrium than would be expected from the plasma contamination and the level of the progesterone “receptor.”
TL;DR: In this paper, the first GeAl bond-containing derivatives of LiAlH 4 have been synthesized by micro-analysis and one of them Li + [(Ph 3 Ge)H 3 Al] −, THF has been identified by microanalysis.
TL;DR: In this paper, the authors showed that triploidy results from retention of the second polar body and make it possible to interpret the origin of other types of ploidy.
Abstract: Eggs of diploid females of Pleurodeles waltlii, fertilized artificially by waltlii sperm, have been submitted to increased temperature of hydrostatic pressure during the first hour of development. Of the resulting viable individuals about 95% were triploid, the remainder diploid or tetraploid. Other types of ploidy have been observed in abnormal embryos (n, 2n/4n, 5n, n/5n, 6n). Some of the treated eggs came from females with a marker chromosome (pericentric inversion). The karyotypes of the animals developing from such eggs confirm that triploidy results from retention of the second polar body and make it possible to interpret the origin of the other types of ploidy. From the results it can be envisaged how gynogenetic animals can be obtained from eggs inseminated by inactivated sperm and shocktreated to restore diploidy.
TL;DR: During courtship, males of Chrysopa perla extrude from the genital aperture two eversible vesicles that bear approximately 50 sclerotized tubercles with a long, apical hair that are characterized by extensive RER, a large amount of SER, probably involved in lipid elaboration, and voluminous myeloid bodies encircling the reservoir.
Abstract: During courtship, males of Chrysopa perla extrude from the genital aperture two eversible vesicles that bear approximately 50 sclerotized tubercles with a long, apical hair. Ultrastructural study reveals within each tubercle two juxtaposed subunits: a sensory subunit formed by a mechanoreceptor neuron, a glial cell, two enveloping cells, and a glandular subunit consisting of a glandular cell provided with an extracellular reservoir, a duct cell and an enveloping cell. The glandular-cell cytoplasm is characterized by extensive RER, a large amount of SER, probably involved in lipid elaboration, and voluminous myeloid bodies encircling the reservoir. The secretion is released to the outside by a cuticular duct that opens into the side of the tubercle. The function of the mechanoreceptor associated with the glandular subunit is discussed.
TL;DR: In this article, a decomposition thermique de l'adduit obtenu avec l'acetylene dicarboxylate de methyle est etudiee.
TL;DR: The vertical excited and ionized states of the formamide molecule were calculated in a (double-zeta + diffuse) AO basis ·set using the CIPSI algorithm.
TL;DR: The formation of new intermediates and especially germaimines R2GeNR′ has been observed in the reaction of germylenes with phenyl azide (precursor of phenylnitrene) as discussed by the authors.
TL;DR: In this article, the chemical shift measurements of silacyclopentenes confirm the results obtained by 1H and 13C NMRs, and they also verify the conclusions obtained by RMN.
Abstract: Les mesures des deplacements chimiques de 29Si dans les silacyclopentenes verifient les conclusions obtenues par RMN de 1H et 13C.
29Si chemical shift measurements of silacyclopentenes confirm the results obtained by 1H and 13C NMR.
TL;DR: In this article, the stability analysis of the hyperbolic and parabolic explicit difference schemes presented in this paper has been improved on, and stability limits that are very near the actual numerical stability limits have been obtained.
Abstract: The stability analysis of the hyperbolic and parabolic explicit difference schemes presented in our previous paper 1 is improved on. Analysis of the Fourier components gives rise to stability limits that are very near the actual numerical stability limits.
TL;DR: The equilibrium between monomeric and trimeric species (Et2GeS)3 is established as discussed by the authors, which is characterized by addition on the germanium-sulfur bond of Et3GeSMe and by insertion and ring expansion reactions with ethylene oxide or thiirane and formation of germaoxathiolane or germadithiolane.