Search results for "chimica"
showing 10 items of 4450 documents
Analisi chimiche su un’antica veste infantile del XVII secolo
2012
NUOVI DERIVATI PIRROLO[2,3-B]PIRIDINICI SOSTITUITI, PROCEDIMENTO PER LA LORO PREPARAZIONE E LORO IMPIEGO TERAPEUTICO.
2013
Electrochemical pH Control at Gold Nanowires
2018
In this work, interdigitated arrays of nanowire electrodes are used with one array acting as the working electrode while the other is used to generate the required protons. Finite element simulations of the pH control electrodes were performed to provide insight on the generation and subsequent diffusion of protons. This informed the inter-tine spacing of the electrodes used.. This electrochemical pH control method was then used to enable the detection of analytes of interest.
Graphene and ionic liquids new gel paste electrodes for caffeic acid quantification
2015
Abstract Graphene/ionic liquids nanocomposite gels were synthesized by an electrochemical etching approach and fully characterized under a morphological and structural point of view. For this purpose, several analytical techniques were applied, as HR-TEM/EDX (High Resolution-Transmission Electron Microscopy/Energy Dispersive X-Ray Analysis); FE-SEM/EDX (Field Emission-Scanning Electron Microscopy/Energy Dispersive X-Ray Analysis); XPS (X-Ray Photoelectron Spectroscopy); FT-IR (Fourier Transform-Infrared Spectroscopy) and electrochemical techniques. After the characterization study, nanocomposite-gel paste electrodes were assembled, exhibiting a selective and specific detection toward the ca…
Nature of Interactions at the Interface of Two Water-Saturated Commercial TiO2 Polymorphs
2013
Two commercial TiO2 samples, a 100% anatase and a 100% rutile, were used for the fast field cycling NMR experiments. The results showed a different behavior between the different samples. In particular, water molecules were unbonded to the solid surface for the rutile sample, whereas they appeared to chemically interact with the surface through H-bond formation with the anatase sample. The above findings accord with the generally lower activity of rutile with respect to anatase reported in literature for photocatalytic oxidation reactions in water. The difficulty of water to interact with rutile surface, indeed, could hinder the formation of OH radicals, which are the most important oxidant…
Home-prepared anatase, rutile, and brookite TiO2 for selective photocatalytic oxidation of 4-methoxybenzyl alcohol in water: reactivity and ATR-FTIR …
2009
5th European Meeting on Solar Chemistry and Photocatalysis -- OCT 04-08, 2008 -- Palermo, ITALY
Photocatalytic thin films of TiO2 formed by a sol-gel process using titanium tetraisopropoxide as the precursor
2008
Abstract Thin TiO 2 films were prepared with the dip-coating technique by using sols deriving from titanium tetraisopropoxide. TiO 2 films were formed on glass substrates previously covered by a SiO 2 layer obtained from a tetraethylortosilicate sol. The films, after a thermal treatment at 673 K, mainly consisted of TiO 2 anatase. The samples were characterised by X-ray diffraction, UV–Vis spectroscopy, scanning electron microscopy and atomic force microscopy. The photoactivity of the various films was tested by using as probe reaction the photo-oxidation of 2-propanol in gas-solid regime. The photoreactivity results indicated that the TiO 2 films were efficient for degrading 2-propanol und…
Phase formation in mixed TiO2-ZrO2 oxides prepared by sol-gel method
2011
Pure titania, zirconia, and mixed oxides (3—37 mol.% of ZrO2) are prepared using the sol-gel method and calcined at different temperatures. The calcined samples are characterized by Raman spectroscopy, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption porosimetry. Measurements reveal a thermal stability of the titania anatase phase that slightly increases in the presence of 3—13 mol.% of zirconia. Practically, the titania anatase-rutile phase transformation is hindered during the temperature increase above 700 C. The mixed oxide with 37 mol.% of ZrO2 treated at 550 C shows a new single amorphous phase with a surface area of the…
Expression of proteolitic enzymes in induced angiogenesis
2008
Angiogenesis (growth of new blood vessels) plays a key role in tissue repair, such as in cancer progression (Folkman 1995. New Engl. J. Med. 333, 1757-63). At the beginning of the process is observed the matrix degradation and endothelial cells (ECs) migration inside to the connective tissue in proximity of vessel walls. During angiogenesis several modifications occurs at plasma membrane level; a redistribution of cell-cell and cell-matrix adhesion molecules (Bazzoni et al 1999), such as an increased expression of several proteolytic enzymes, including MMPs and serine proteases, as plasminogen activators and SIMPs, were observed (Ghersi et al. 2006. Cancer Res. 66, 4652-61; Ghersi 2008 Fron…
Could beta-catenin regulate the expression of proteolitic enzymes during angiogenesis?
2009
During angiogenesis several modifications occurs at endothelial cell plasma membrane level as: MT-MMPs and serine integral membrane proteases (SIMPs) over-expression. Moreover, when endothelial cells during angiogenesis acquired a mesenchymal phenotype the cell-cell interactions mediate by cadherins are lost and β-catenin, a stabilizer of interaction occurring between cadherins and cytoscheleton, can translocate to the nucleus where acts as transcription factor in association to TCF/LEF. Our experiments were focalized to the expression/activation of proteolytic enzymes when cell-cell contacts are perturbed, by mechanical or site specific perturbations. We have analyzed the mRNA, proteins an…