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Maccotta A Fantazzini P Garavaglia C Donato ID Perzia P Brai M Morreale F 《Annali di chimica》2005,95(3-4):117-124
Magnetic Resonance Relaxation (MRR) and Magnetic Resonance Imaging (MRI) are powerful tools to obtain detailed information on the pore space structure that one is unlikely to obtain in other ways. These techniques are particularly suitable for Cultural Heritage materials, because they use water 1H nuclei as a probe. Interaction with water is one of the main causes of deterioration of materials. Porous structure in wood, for example, favours the penetration of water, which can carry polluting substances and promote mould growth. A particular case is waterlogged wood from underwater discoveries and moist sites; in fact, these finds are very fragile because of chemical, physical and biological decay from the long contact with the water. When wood artefacts are brought to the surface and directly dried in air, there is the collapse of the cellular structures, and wood loses its original form and dimensions and cannot be used for study and museum exhibits. In this work we have undertaken the study of some wood finds coming from Ercolano's harbour by MRR and MRI under different conditions, and we have obtained a characterization of pore space in wood and images of the spatial distribution of the confined water in the wood. 相似文献
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Silvano Bozzini Patrizia Nitti Giuliana Pitacco Alessandro Pizzioli Claudio Russo 《Journal of heterocyclic chemistry》1996,33(4):1217-1221
Tricyclic compounds with an imidazolinone ring fused to 1,2- and 1,4-naphtoquinones were synthesized by a reaction of 4-amino-1,2-naphthoquinone and 2-amino-1,4-naphthoquinone with electrophilic symmetric and non symmetric diazenes. 相似文献
116.
Malandrino G Perdicaro LM Condorelli G Fragalà IL Rossi P Dapporto P 《Dalton transactions (Cambridge, England : 2003)》2006,(8):1101-1106
A novel nickel beta-diketonate adduct, Ni(tta)2.tmeda, has been synthesized using 2-thenoyltrifluoroacetone as the beta-diketonate and N,N,N,'N'-tetramethylethylendiamine as the Lewis base. It has been characterized by elemental analyses, IR, 1H NMR, 13C NMR spectroscopy and single-crystal X-ray diffraction studies. Physical and thermal properties of Ni(tta)2.tmeda precursor have been also extensively investigated. Its efficacy as a metal-organic chemical vapour deposition (MOCVD) precursor for the growth of nickel oxide films has been fully tested by applying it to the deposition of NiO films on quartz substrate. NiO thin films have been characterized by X-ray diffraction (XRD), scanning electron microscopy and UV spectroscopy. 相似文献
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Gulmini M Appolonia L Framarin P Mirti P 《Analytical and bioanalytical chemistry》2006,386(6):1815-1822
Twelve finds from archaeological excavations carried out in the Aosta region (Italy) were studied by scanning electron microscopy
coupled with energy-dispersive X-ray detection (SEM–EDS). The archaeological samples were shards of glazed pottery dating
from the fourth to the seventh century AD. Analysis of ceramic bodies revealed a general homogeneity in composition among
the studied samples and the use of a noncalcareous clay for their manufacture; however, two shards stand out due to their
high iron contents. Glazes proved to be high-lead products with more than 70% PbO in all of the samples investigated but one.
For the latter, a composition poorer in lead and richer in silicon, aluminium and iron was found. SEM observation of the contact
region between body and glaze suggests that the vitreous coatings were mostly obtained by applying the glazing components
onto the unfired clay body; moreover, a comparison between clay and glaze compositions suggests the use of a lead compound
mixed with a silica-rich material, not a lead compound by itself. 相似文献
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Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features. 相似文献
120.
Marta Balietti Belinda Giorgetti Giuseppina Di Stefano Tiziana Casoli Daniela Platano Moreno Solazzi Carlo Bertoni-Freddari Giorgio Aicardi Fabrizia Lattanzio Patrizia Fattoretti 《Micron (Oxford, England : 1993)》2010,41(2):143-148
Ketogenic diets (KDs) have been applied in the therapy of paediatric epilepsy for nearly a century. Recently, beneficial results have also been reported on metabolic disorders and neurodegeneration, designating aged individuals as possible recipients. However, KDs efficacy decrease after the suckling period, and very little is known about their impact on the aging brain. In the present study, the effect on the neuronal energetic supply of a KD containing 20% of medium chain triglycerides (MCT) was investigated in Purkinje cells of the cerebellar vermis of late-adult (19-month-old) rats. The animals were fed with the KD for 8 weeks, and succinic dehydrogenase (SDH) activity was cytochemically determined. The following parameters of SDH-positive mitochondria were evaluated by the use of a computer-assisted image analysis system connected to a transmission electron microscope: numeric density (Nv), average volume (V), volume density (Vv), and cytochemical precipitate area/mitochondrial area (R). Young, age-matched, and old animals fed with a standard chow were used as controls. We found significantly higher Nv in MCT-KD-fed rats vs. all the control groups, in young vs. late-adult and old controls, and in late-adult vs. old controls. V and Vv showed no significant differences among the groups. R was significantly higher in MCT-KD-fed rats vs. all the control animals, and in old vs. young and late-adult controls. Present data indicate that the ketogenic treatment counteracted age-related decrease in numeric density of SDH-positive mitochondria, and enhanced their metabolic efficiency. Given the central role of mitochondrial impairment in age-related physio-pathological changes of the brain, these findings may represent a starting point to examine novel potentialities for KDs. 相似文献