The structure and properties of Ba2YCu3O6

Santoro, A.; Miraglia, S.; Beech, F.; Sunshine, Steven A.; Murphy, D. W.; Schneemeyer, Lynn; Waszczak, J. V.

doi:10.1016/0025-5408(87)90100-0

Cited by 167 publications

(18 citation statements)

References 5 publications

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“…Our strategy for studying and manipulating autoimmune disease experimentally has been to isolate, in culture, lines and clones of T lymphocytes functionally active in producing expermental autoimmune encephalomyelitis (EAE), experimental autoimmune thyroiditis, or adjuvant arthritis (4-7). These T cells have been useful in investigating factors in pathogenesis such as the identity of critical self-epitopes (8,9), traffic of autoinimune T lymphocytes through blood vessels to target organs (10,11), and interactions between autoimmune T lymphocytes and target tissues (12,13). Autoimmune T lymphocytes, in addition to probing pathogenesis, can be rendered avirulent and used to induce resistance to the specific autoimmune disease with which they are associated.…”

Section: W E Have Induced Resistancementioning

confidence: 99%

Role of the Protein Moiety of Ribonuclease P, a Ribonucleoprotein Enzyme

Reich

Olsen

Pace

et al. 1988

Science

237

174

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The Bacillus subtilis ribonuclease P consists of a protein and an RNA. At high ionic strength the reaction is protein-independent; the RNA alone is capable of cleaving precursor transfer RNA, but the turnover is slow. Kinetic analyses show that high salt concentrations facilitate substrate binding in the absence of the protein, probably by decreasing the repulsion between the polyanionic enzyme and substrate RNAs, and also slow product release and enzyme turnover. It is proposed that the ribonuclease P protein, which is small and basic, provides a local pool of counter-ions that facilitates substrate binding without interfering with rapid product release.

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Section: W E Have Induced Resistancementioning

confidence: 99%

Role of the Protein Moiety of Ribonuclease P, a Ribonucleoprotein Enzyme

Reich

Olsen

Pace

et al. 1988

Science

237

174

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“…Neutron diffraction has shown that the structures of the material at oxygen stoichiometry limits 06 and 07 differ primarily in the existence of one-dimensional Cu-O chains in the 07 material that are absent at 0q. 4 More recent work also shows these chains to be partially filled at intermediate stoichiometries. 6 Therefore as a simple first order model for the chemical equilibrium represented by the data in figure 1, we may write:…”

Section: Methodsmentioning

confidence: 92%

Kinetics and Thermodynamics of the Reaction of Molecular Oxygen with YBa₃Cu₃O_x

et al. 1987

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The sensitivity of the properties of RBa2Cu3Ox materials to oxygen stoichiometry has been widely reported.1 This is a serious problem in the synthesis and processing of these compounds since many operations must be carried out at temperatures and oxygen partial pressures where bulk oxygen is in dynamic equilibrium with gas phase molecular oxygen. Therefore it is crucial for the rational design of processing strategies to understand how the equilibria and kinetics of oxygen stoichiometry in this material vary with temperature and pressure. In this paper we report work on two problems in this area: first, we describe the development of accurate methods for the determination of oxygen stoichiometry in experimental samples, and second, the use of these methods to investigate and analyze equilibrium oxygen contents over a range of temperatures and oxygen partial pressures. Equilibrium oxygen contents from 350 – 900°C at oxygen pressures of. 05, .21, and 1.00 atmospheres have been determined. The pressure dependence has also been examined over a wider range at selected temperatures. Most of this data can be adequately fit to a model which assumes that a single chemical equilibrium constant can describe the entire stoichiometry range from x=6 to 7. However, kinetic data suggests that the detailed mechanism must be more complex, and that the overall thermochemistry may reflect contributions from a number of interacting processes rather than any single elementary step. In concurrent work we have used these methods to develop sample series that can be used to examine magnetic properties2 and far IR spectra3 of these materials as a systematic function of oxygen content.

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“…The value of the critical temperature T c decreases as x decreases, and it becomes equal to zero when the orthorhombic to tetragonal transition takes place. When x = 6.0, all O(4) and O(5) sites are empty, and the coordinations of Cu(1) and Ba became two and eight-fold, respectively [58]. …”

Section: Structural Studiesmentioning

confidence: 99%

Past and present crystallographic work at the NBS/NIST reactor

Santoro

2001

J. Res. Natl. Inst. Stand. Technol.

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Neutron diffraction at NBS/NIST started soon after the NBS reactor became operational in the summer of 1969. Since that time, literally hundreds of crystal structures have been determined and refined using single crystal and powder neutron diffraction data, collected with a variety of instruments. This work has been usually done in collaboration with other NBS/NIST divisions and/or universities and industrial laboratories. In parallel with the technical developments and the experimental work, also theoretical aspects of crystal geometry have been clarified, and significant improvements in the techniques of profile refinements have been made. It is therefore understandable that a comprehensive description of all the crystallographic studies carried out up to the present is impossible under the constraints of space and time imposed by a review of this type, and, in the following sections, we will limit ourselves to give, only a brief account of the topics which, in our opinion, represent the highlights of the work carried out at the reactor.

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The structure and properties of Ba2YCu3O6

Cited by 167 publications

References 5 publications

Role of the Protein Moiety of Ribonuclease P, a Ribonucleoprotein Enzyme

Role of the Protein Moiety of Ribonuclease P, a Ribonucleoprotein Enzyme

Kinetics and Thermodynamics of the Reaction of Molecular Oxygen with YBa₃Cu₃O_x

Past and present crystallographic work at the NBS/NIST reactor

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The structure and properties of Ba2YCu3O6

Cited by 167 publications

References 5 publications

Role of the Protein Moiety of Ribonuclease P, a Ribonucleoprotein Enzyme

Role of the Protein Moiety of Ribonuclease P, a Ribonucleoprotein Enzyme

Kinetics and Thermodynamics of the Reaction of Molecular Oxygen with YBa3Cu3Ox

Past and present crystallographic work at the NBS/NIST reactor

Contact Info

Product

Resources

About

Kinetics and Thermodynamics of the Reaction of Molecular Oxygen with YBa₃Cu₃O_x