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M. Belli A. Scafati A. Bianconi E. Burattini S. Mobilio C. R. Natoli L. Palladino A. Reale 《Il Nuovo Cimento D》1983,2(5):1281-1304
Summary The binding of Mn2+ ions to ATP molecules has been studied by means of the fine-structure analysis of X-ray absorption spectra (EXAFS and XANES)
at theK-edge of Mn using the synchrotron, radiation facility PULS in Frascati. The results obtained in both freeze-dried and liquid
samples of aqueous solutions at room temperature of the Mn-ATP complex under diffrent values ofpH and Mn:ATP ratio are reported and discussed. The Mn2+ ion appears to be octahedrally coordinated, the phosphate oxygen atoms being in the first co-ordination shell. Values of
(2.15±0.05) ? and (3.4±0.05) ?, respectively, have been found for Mn-O and Mn-P distances. Theoretical considerations together
with experimental results do not support the existence of a direct binding of the Mn to the N(7) atom of the adenine ring.
The coordination numbers for the first and second shell are consistent with the formation of a Mn(ATP)2 complex in solution atpH=9 and Mn: ATP=1:10, while a Mn-ATP 1:1 complex is found at lowerpH and higher Mn: ATP ratios.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
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Background
Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH. 相似文献7.
Alessandra Ciapponi Stéphanie Palmier Jean-Yves Natoli Laurent Gallais 《Journal of luminescence》2009,129(12):1786-1789
Hafnia thin films for high-power optical coatings have been characterized by photoluminescence pumped by 4.66 eV photons and photothermal deflection measurements. These data are compared to the statistical laser damage behavior in order to find correlations between destructive and non-destructive characterizations. Thin films have been produced at two thicknesses and using different thin-film deposition techniques typically employed for optical coating fabrication: EBD (HfO2 target), EBD (Hf target), RLVIP and DIBS. The photoluminescence spectra show significant differences depending on the deposition techniques and thicknesses. EBD films show significant luminescence but the luminescence of ion-assisted films could not be distinguished from the uncoated substrate. All EBD coating spectra could be described by a linear combination of four bands. Further, XRD measurements show that the 255-nm-thick films had a relatively high crystallinity: EBD films contained the monoclinic phase and the ion-assisted films contained oriented nanocrystals of orthorhombic hafnia. The presence of orthorhombic phases indicates high compressive strain quenching the photoluminescence of these samples. 相似文献
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Bongiorno D Ceraulo L Filizzola F Fontana G Natoli MC 《Rapid communications in mass spectrometry : RCM》2006,20(20):3081-3088
The electron ionization (EI)-induced fragmentations of a series of 1,1-(2,2'-dimethoxyphenyl)-substituted 2-methylpropanes (1-20) in both 70 eV and mass-analyzed ion kinetic energy (MIKE) spectra have been investigated. The EI-MS spectra of these compounds are characterized by the presence of abundant benzyl ions. These ions result from competitive hydrogen migration from the 2- and 2'-methoxy groups on the carbenium center of the diphenylmethyl cations formed by benzylic cleavage of the molecular ions. The relative abundances of the benzyl ions arising from such competitive processes are discussed and rationalized. The steric effect of the 3- or 3'-substituents is the main discriminating factor between the two competitive processes. The structural information, arising either from the 70 eV or the MIKE spectra, is discussed. 相似文献
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Methodological advances in multiple scattering theory (MST) in both wave and Green's function versions are reported for the calculation of electronic ground and excited state properties of condensed matter systems with an emphasis on core-level photoemission and absorption spectra. Full-potential MST is reviewed and extended to non-local potentials. Multichannel MST is reformulated in terms of the multichannel density matrix whereby strong electron correlation of atomic multiplet type can be accounted for in both ground and excited states. 相似文献
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A Mukherjee M Dasgupta DJ Hinde CR Morton AC Berriman RD Butt JO Newton H Timmers 《Pramana》2001,57(1):195-198
Fusion cross-sections for the 7Li + 12C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy
evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their
contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections
due to the breakup of 7Li may not be significant for 7Li + 12C reaction at energies around the barrier. 相似文献