962 resultados para 109-1


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Structural and conformational properties of 1H-Isoindole-1,3(2H)-dione, 2-[(methoxycarbonyl)thio] (S-phthalimido O-methyl thiocarbonate) are analyzed using a combined approach including X-ray diffraction, vibrational spectra and theoretical calculation methods. The vibrational properties have been studied by infrared and Raman spectroscopies along with quantum chemical calculations (B3LYP and B3PW91 functional in connection with the 6-311++G** and aug-cc-pVDZ basis sets). The crystal structure was determined by X-ray diffraction methods. The substance crystallizes in the monoclinic P2(1)/c space group with a = 6.795(1), b = 5.109(1), c = 30.011(3) angstrom, beta = 90.310(3)degrees and Z = 4 molecules per unit cell. The conformation adopted by the N-S-C=O group is syn (C=O double bond in synperiplanar orientation with respect to the N-S single bond). The experimental molecular structure is well reproduced by the MP2/aug-cc-pVDZ method. (C) 2010 Elsevier B.V. All rights reserved.

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Glycogen levels in liver and skeletal muscle assessed non-invasively using magnetic resonance spectroscopy after a 48-h pre-study period including a standardized diet and withdrawal from exercise did not differ between individuals with well-controlled Type 1 DM and matched healthy controls.

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40Ar/39Ar geochronological studies were performed on basalts taken from the bottom of Hole 462A. An age of 129.7 ± 4.6 Ma was obtained for two temperature fractions (800 and 1000°C) of Sample 462A-109-1, 106-108 cm. That age is between the age of the oceanic basement, as deduced from the magnetic anomaly data, and the age of interlayered sediment, as deduced from the sparse fossil content.

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The porewater and sediment composition of two boxcores and of a small gravity core, taken on a manganese-nodule-covered hill and in the Madeira Abyssal Plain proper respectively, are compared. The pore-water study of the two boxcores indicates that oxic conditions prevail in both cores. In addition, it indicates that no detectable fluxes of Mn or Fe occur from the porewater to the ocean bottom water. Variations in the geochemical composition of the sediments can be explained by fluctuations in the amount of carbonate, which acts as a diluting agent. A clear carbonate minimum is observed at 20-22 cm depth in the two cores. This minimum is likely to be associated with the last glacial period (10-20 kyr B.P.). This association is supported by the sediment accumulation rate of 15 mm/kyr as found by extrapolation from the rate for pelagic sediments in the Madeira Abyssal Plain. The bulk composition of the manganese nodules recovered from the submarine hill is chemically almost identical to the average composition of Atlantic nodules. The trace metal and Rare Earth Elements composition indicate a hydrogenous origin for the manganese nodules of this study. On the basis of the chemical composition, and that of nodules relative to that of the adjacent sediments, an average nodule accretian rate of 2.8-3.3 mm/myr has been calculated. Although the analyses of the entire ferromanganese nodules that have been studied seem to indicate a homogenous composition, internal structures of the nodules reveal great inhomogeneity, both visually and chemically. These fluctuations may be related to variations in the fluxes of Mn and Fe, which in turn could be climate-related.