1,721,038 research outputs found
Blakely (T.D.), Van Beek (W.), Thomson (D.L.) eds : Religion inAfrica. Experience and Expression
No full textLaburthe-Tolra Philippe. Blakely (T.D.), Van Beek (W.), Thomson (D.L.) eds : Religion inAfrica. Experience and Expression. In: Revue française d'histoire d'outre-mer, tome 83, n°311, 2e trimestre 1996. pp. 114-115
Appearance of altered cell-surface fucosyl glycopeptides in concomitance with chromosomal alterations in the gross virus-infected pre-leukemic thymus of the rat
No full textThe appearance of a class of fast-eluting cell-surface glycopeptides that are encountered almost exclusively in malignant and certain pre-malignant cells was monitored in the course of leukemogenesis in the thymus of rats injected at birth with Gross leukemia virus. The altered glycopeptides appeared as early as 15 days after virus injection, when the animals were still clinically healthy and no histological signs of the disease were present in the thymus. Their amount was further increased at 30 days, and reached a maximum in the fully developed lymphoma. The development of this early phenotypic marker of malignancy appeared to be concomitant with that of chromosomal anomalies in the thymus. Since these anomalies are non-random, the existence of a causal relationship between the glycopeptide change and the loss of specific chromosomes might be hypothesized
Crystal structure and solid-state transformations of Zn-triethanolamine-acetate complexes to ZnO
No full textThe rapid and massive formation of a foamy precipitate while reacting zinc acetate (Zn(Ac)2) and triethanolamine (TEA) in proper conditions led to an unravelled complex and a molecular tetra- metallic zinc cluster: their synthesis was optimised and they were characterised by single crystal X-ray diffraction. The structure shows the direct link of the acetate anion to the Zn cation, a feature not observed in parent compounds. The structural and chemical evolution of these materials upon heating have been studied, targeting the production of zinc oxide thin films or particles with particular properties. The phase transitions occurring during thermal treatments and the conversion to ZnO were studied by in situ X-ray powder diffraction, thermo-gravimetry and Raman spectroscopy. The cluster structure can be considered an even more interesting precursor for zinc oxide as nano-aggregates of four ZnO moieties are already present and the formation of ZnO particles requires a smaller number of broken and newly formed bonds. A third metastable hydrated phase was identified, but not structurally characterised because of its instability, thus completing the exploration of the polymorph landscape of the title compound
Understanding the physico-chemical properties of polyhedral oligomeric silsesquioxanes: a variable temperature multidisciplinary study
No full textStudying modifications and reactions in materials by simultaneous Raman and X-ray powder diffraction at non-ambient conditions: methods and applications
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Powder metallurgical nanostructured medium carbon bainitic steel: kinetics, structure, and in-situ thermal stability studies
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Untangling diffraction intensity: modulation enhanced diffraction on ZrO2 powder
No full textThis paper describes a new method for extracting the individual contributions to the diffracted intensity of subsets of atoms in the crystal structure. The periodic perturbation of the scattering process, required for untangling the scattered intensity, is provided by altering the resonant contributions. The theory of modulation enhanced diffraction (MED) is briefly recalled in the context of resonant scattering. A periodic variation in the atomic form factor has been achieved by changing the X-ray energy in such a way that the MED theory holds. Simulated results and experimental data are presented, together with necessary corrections. Two data analysis schemes are presented, both illustrating the advantages and drawbacks of the novel modulation technique.
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