Synthesis and structural characterization of a novel dinuclear complex compound formed by the aerial oxidation of cobalt(II) having an interligand C-C sigma-bond

The aerial oxidation of cobalt(II) salt, in a methanolic solution, containing a hydrazone ligand, (E)-N'-(4-oxo-4-phenylbutan-2-ylidene)benzohydrazide (condensation product of benzoyl acetone and benzhydrazide, LH2) leads to the coupling of two such ligand units through the formation of a rather long C-C bond [1.601(6) A] giving rise to a dinuclear Co (III) hydrazone complex, [Co2(L)2(L')(].0.25H2O (L' = C-C coupled hydrazone ligand). The structure of the complex has been determined by X-ray crystallography and IR, UV-Vis spectroscopy and elemental analysis have characterized the complex.     

Surface-enhanced Raman and fluorescence joint analysis of soil humic acids

Surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF) combined emissions were used in this work to the analysis of humic acids (HA). This study examined HA structure at different pH and HA concentrations and assessed the structural differences taking place in HA as a result of various amendment trials. Raman and fluorescence emissions behave in opposite ways due to the effect of the metal surface on the aromatic groups responsible for these emissions. The information afforded by these techniques can be successfully employed in the structural and dynamic analysis of these important macromolecules. The surface-enhanced emission (SEE) spectra, that is the sum of the Raman and the fluorescence emissions, were acquired by using both macro- and micro-experimental configurations in order to apply imaging and confocal Raman and fluorescence spectroscopy techniques on the analysis of HA.     

Structure/transport relationships in silver-based oxide glasses: 1-D and 2-D NMR information

AgI-doped silver oxide glasses are of interest both for their possible applications in electrochemical devices, and as a model system to study the transport/structure relationships in ionic glasses. Here we summarize the information given by 1-D and 2-D solid-state NMR measurements on both the cations dynamics and short (and medium) range structure of several glassy systems. Emphasis is given to understand how AgI enters into the glass matrix. A new and careful analysis of our previously reported 109Ag 1-D data shows that the glass matrix plays a relevant role in determining the efficiency of carriers formation, as well as their mobility. Finally, as an example of a modern 2-D NMR application to these materials, we report the first 11B and 17O Multiple Quantum MAS study on a glass of the system AgI:Ag2O:2B2O2, which confirms the nearly complete absence of non-bridging oxygens (NBOs) in the silver diborate composition.     

Photoacoustic detection of nitric oxide by use of a quantum-cascade laser

A photoacoustic trace-gas sensor for the measurement of nitric oxide with a detection limit of 500 parts in 10(9) has been demonstrated. The radiation source was a thermoelectrically cooled distributed-feedback quantum-cascade laser operating in pulsed mode near 5.3 microm with an average laser power of 8 mW. A resonant photoacoustic cell was excited in its first longitudinal mode by the modulated laser light. Preliminary measurements have been performed to test the performance of our photoacoustic sensor; possible improvements to reach lower detection limits are discussed.     

Radiation damage of silicate glasses doped with Tb and Eu

In this work, we studied a set of Tb³⁺ (or Eu³⁺) doped silicate glasses in which some amounts of BaO were added to increase glass density. The irradiation-induced damage was investigated by absorbance measurements performed before and after each irradiation with doses ranging from 3 to 237 Gy. Analysed glasses underwent also light yield measurements investigated in terms of light production. The results showed that radiation damage and light yield depend on glass composition and are very low for the Eu³⁺ containing glass and for the Tb³⁺ activated glass which contains also lead. A possible explanation could be that lead and europium favour in the glass matrix the formation of a higher concentration of defects with respect to Tb³⁺ doping ions.     

Pentacoordination in dichloro-N-2-methylthiophenyl-2′-pyridylmethyleneiminecopper(II)

Dichloro-N-2-methylthiophenyl-2-pyridylmethyleneiminecopper(II) is monoclinic:P2₁/c;a = 8·49(1),b = 10·80(1),c = 15·67(1) Å, = 92·0(3)·,Z = 4. The crystal structure has been determined at room temperature from three-dimensional X-ray photographic data and refined by differential methods with anisotropic thermal parameters to a finalR value of 8·1%. Cu(II) coordinates to two chlorine atoms (Cu-Cl = 2·255,2·443 Å) and to one sulphur (Cu-S = 2·341 Å) and to two nitrogen atoms (Cu-N = 2·011, 2·014 Å) from methylthiophenylpyridylmethyleneimine; this represents a distorted tetragonal pyramid with the organic molecule behaving as a tridentate ligand. Packing is determined by normal van der Waals contacts.     

Production of a Functional Human Acid Maltase in Tobacco Seeds: Biochemical Analysis, Uptake by Human GSDII Cells, and In Vivo Studies in GAA Knockout Mice

Genetic deficiency of acid alpha glucosidase (GAA) results in glycogen storage disease type II (GSDII) or Pompe’s disease. To investigate whether we could generate a functional recombinant human GAA enzyme (tobrhGAA) in tobacco seeds for future enzyme replacement therapy, we subcloned the human GAA cDNA into the plant expression plasmid-pBI101 under the control of the soybean β-conglycinin seed-specific promoter and biochemically analyzed the tobrhGAA. Tobacco seeds contain the metabolic machinery that is more compatible with mammalian glycosylation?phosphorylation and processing. We found the tobrhGAA to be enzymatically active was readily taken up by GSDII fibroblasts and in white blood cells from whole blood to reverse the defect. The tobrhGAA corrected the enzyme defect in tissues at 7 days after a single dose following intraperitoneal (IP) administration in GAA knockout (GAA^?/?) mice. Additionally, we could purify the tobrhGAA since it bound tightly to the matrix of Sephadex G100 and can be eluted by competition with maltose. These data demonstrate indirectly that the tobrhGAA is fully functional, predominantly proteolytically cleaved and contains the minimal phosphorylation and mannose-6-phosphate residues essential for biological activity.     

Recherches générales sur les sourbes et les surfaces réglées algébriques

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