Results 211 to 220 of about 249,399 (261)
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Chemical Reviews, 2013
An unambiguous definition of conformational change and conformational polymorphism, as well as a quantitative basis for the likelihood of its appearance, is reviewed. Conformational adjustment and conformational change are different phenomena. Two polymorphs are conformational polymorphs only if their conformations are related by conformational change.
Cruz-Cabeza, A.J., Bernstein, J.
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An unambiguous definition of conformational change and conformational polymorphism, as well as a quantitative basis for the likelihood of its appearance, is reviewed. Conformational adjustment and conformational change are different phenomena. Two polymorphs are conformational polymorphs only if their conformations are related by conformational change.
Cruz-Cabeza, A.J., Bernstein, J.
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Proceedings of the 13th International Conference on Database Theory, 2010
We examine schema mappings from a type-theoretic perspective and aim to facilitate and formalize the reuse of mappings. Starting with the mapping language of Clio, we present a type-checking algorithm such that typable mappings are necessarily satisfiable.
Ryan Wisnesky +2 more
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We examine schema mappings from a type-theoretic perspective and aim to facilitate and formalize the reuse of mappings. Starting with the mapping language of Clio, we present a type-checking algorithm such that typable mappings are necessarily satisfiable.
Ryan Wisnesky +2 more
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The Journal of Physical Chemistry Letters, 2022
Hydrogenated borophenes─borophanes─have recently been synthesized as a new platform for studying low-dimensional borides, but most of their lattice structures remain unknown. Here, we determine the structures of borophane polymorphs on Ag(111) by performing extensive structural search using the cluster expansion method augmented with first-principles ...
Ying Xu +6 more
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Hydrogenated borophenes─borophanes─have recently been synthesized as a new platform for studying low-dimensional borides, but most of their lattice structures remain unknown. Here, we determine the structures of borophane polymorphs on Ag(111) by performing extensive structural search using the cluster expansion method augmented with first-principles ...
Ying Xu +6 more
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Acta Crystallographica Section C Crystal Structure Communications, 2001
Pentacene, C(22)H(14), crystallizes in different morphologies characterized by their d(001)-spacings of 14.1, 14.5, 15.0 and 15.4 A. We have studied the crystal structure of the 14.1 and 14.5 A d-spacing morphologies grown by vapour transport and from solution. We find a close correspondence between the 14.1 A structure reported by Holmes, Kumaraswamy,
Mattheus, C. C. +5 more
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Pentacene, C(22)H(14), crystallizes in different morphologies characterized by their d(001)-spacings of 14.1, 14.5, 15.0 and 15.4 A. We have studied the crystal structure of the 14.1 and 14.5 A d-spacing morphologies grown by vapour transport and from solution. We find a close correspondence between the 14.1 A structure reported by Holmes, Kumaraswamy,
Mattheus, C. C. +5 more
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Polymorphism of clarithromycin
Archives of Pharmacal Research, 2000It is well recognized that physicochemical properties of drugs are affected by the type of polymorphic crystalline form of drugs. Clarithromycin is known to exist in at least three polymorphic crystalline forms. Since conventional means to obtain the most thermodynamically stable form (Form II) for the antibiotics is known to be associated with a low ...
Y T, Sohn, J K, Rhee, W B, Im
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Journal of Theoretical Biology, 1993
It is well known that for a single, autosomal locus with differential viabilities convergence to a stable equilibrium is assured. However if new alleles are introduced sequentially by mutation the final equilibrium may depend on the particular sequence. Thus the equilibrium to which the population moves will be randomly determined.
C, Cannings, J P, Tyrer, G T, Vickers
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It is well known that for a single, autosomal locus with differential viabilities convergence to a stable equilibrium is assured. However if new alleles are introduced sequentially by mutation the final equilibrium may depend on the particular sequence. Thus the equilibrium to which the population moves will be randomly determined.
C, Cannings, J P, Tyrer, G T, Vickers
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2005
Compression is an economical and efficient way of data handling in not only communication, but also storage purposes. We aimed to implement a compression application based on frequent use of English letters, digraphs, trigraphs and tetragraphs without sacrificing memory and/or the other resources.
Umit Topaloglu, Coskun Bayrak
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Compression is an economical and efficient way of data handling in not only communication, but also storage purposes. We aimed to implement a compression application based on frequent use of English letters, digraphs, trigraphs and tetragraphs without sacrificing memory and/or the other resources.
Umit Topaloglu, Coskun Bayrak
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Journal of Pharmaceutical Sciences, 1972
An evaluation of entropies and enthalpies of transition and fusion and a comparison of X-ray diffraction patterns and IR spectra of polymorphic forms of structurally related compounds were undertaken to obtain information which might prove useful in correlating the frequency of occurrence of polymorphism with certain aspects of chemical structure ...
S S, Yang, J K, Guillory
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An evaluation of entropies and enthalpies of transition and fusion and a comparison of X-ray diffraction patterns and IR spectra of polymorphic forms of structurally related compounds were undertaken to obtain information which might prove useful in correlating the frequency of occurrence of polymorphism with certain aspects of chemical structure ...
S S, Yang, J K, Guillory
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Acta Crystallographica Section C Crystal Structure Communications, 1996
The title compound, 7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diyl diacetate, C21H23NO5, was crystallized from a solution of its hydrochloride and sodium acetate. Unlike prior reports in which crystals were hexagonal shaped (orthorhombic) and in space group P2(1)2(1)2(1), the crystals in the present determination grew as large prisms (monoclinic ...
J R, Deschamps +2 more
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The title compound, 7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diyl diacetate, C21H23NO5, was crystallized from a solution of its hydrochloride and sodium acetate. Unlike prior reports in which crystals were hexagonal shaped (orthorhombic) and in space group P2(1)2(1)2(1), the crystals in the present determination grew as large prisms (monoclinic ...
J R, Deschamps +2 more
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Journal of Pharmaceutical Sciences, 1989
As the solubility in water of the cytotoxic drug estramustine is less than 1 mg/L, polymorphism can have an impact on the bioavailability of orally administered drug. Therefore, the solid state characteristics of estramustine samples, crystallized from different solvents, were investigated by means of X-ray crystallography, thermal analysis, and IR ...
T, Wadsten, N O, Lindberg
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As the solubility in water of the cytotoxic drug estramustine is less than 1 mg/L, polymorphism can have an impact on the bioavailability of orally administered drug. Therefore, the solid state characteristics of estramustine samples, crystallized from different solvents, were investigated by means of X-ray crystallography, thermal analysis, and IR ...
T, Wadsten, N O, Lindberg
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