Search results for " Polymer"
showing 10 items of 3533 documents
Evidence of oxidative stress in very long chain fatty acid--treated oligodendrocytes and potentialization of ROS production using RNA interference-di…
2011
X-linked adrenoleukodystrophy (X-ALD) and pseudo neonatal adrenoleukodystrophy (P-NALD) are neurodegenerative demyelinating diseases resulting from the functional loss of the peroxisomal ATP-binding cassette transporter D (ABCD1) and from single peroxisomal enzyme deficiency (Acyl-CoA oxidase1: ACOX1), respectively. As these proteins are involved in the catabolism of very long chain fatty acids (VLCFA: C24:0, C26:0), X-ALD and P-NALD patients are characterized by the accumulation of VLCFA in plasma and tissues. Since peroxisomes are involved in the metabolism of reactive oxygen species (ROS) and nitrogen species (RNS), we examined the impact of VLCFA on the oxidative status of 158N murine o…
Electrocatalytic properties of manganese and cobalt polyporphine films toward oxygen reduction reaction
2018
International audience; Novel member of polymetalloporphines, namely manganese polymetalloporphine of type I (pMnP-I) obtained by ion exchange from magnesium polyporphine of type I (pMgP-I) is reported for the first time and compared to its cobalt analogue (pCoP-I). Both polymer films have been obtained via two-step procedure: demetaladon of the pMgP-I electrode film via its exposure to trifluoroacetic acid solution, resulting in formation of the metal-free polyporphine of type I (pH(2)P-I) followed by electrochemically induced incorporation of Co or Mn ions from the acetonitrile solution of cobalt and manganese perchlorates. A further oxidative transformation of pCoP-I, polymer films has l…
PHEA-Dox nanoparticles as pH-sensitive model for drug delivery in tumour treatment.
2015
PHEA-Dox nanoparticles as pH-sensitive model for drug delivery in tumour treatment. S. Camporaa, G. Adamoa, N. Maurob, C. Scialabbab, M. Licciardib, G. Giammonab and G. Ghersia. aDipartmento di “Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche” (STEBICEF), Università di Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy. bLaboratory of Biocompatible Polymers, Dipartmento di “Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche” (STEBICEF), Università di Palermo, Via Archirafi, 32 90123 Palermo, Italy. Classical chemotherapeutic applications, using molecules such as doxorubicin (Dox), have side effects due to an unspecific action. In order to obtain a specific release of…
Copper( ii ) complexes with phosphorylated 1,10-phenanthrolines: from molecules to infinite supramolecular arrays
2016
International audience; The reaction of phosphorylated 1,10-phenanthrolines 3-Pphen, 3,8-Pphen and 4,7-Pphen (3-Pphen = 3-diethoxyphosphorylphenanthroline, 3,8-Pphen = 3,8-bis(diethoxyphosphoryl) phenanthroline, 4,7-Pphen = 4,7-bis(diethoxyphosphoryl) phenanthroline) and hydrated copper(II) nitrate in a 1 : 1 ratio leads to the formation of supramolecular architectures. In the 1D coordination polymer [Cu(3-Pphen)(NO3)(2)](n) (2) the copper atom is coordinated to only one phenanthroline ligand and the coordination sphere is completed by two oxygen atoms of nitrate anions and the oxygen atom of the phosphoryl group from the neighbouring phenanthroline ligand. Complex Cu(3,8-Pphen)(NO3)(2) (3)…
Interplay between spin transition and gas sorption in compartmentalized coordination polymers
2019
El trabajo descrito en esta tesis se enmarca dentro de los polímeros de coordinación compartimentalizados. Los polímeros de coordinación son materiales híbridos orgánicos-inorgánicos formados por un metal rodeado por unos ligandos orgánicos unidos mediante enlace de coordinación y se pueden obtener estructuras que se extienden en una, dos o tres direcciones del espacio. Las infinitas posibilidades que existen debido a la gran variedad de metales disponibles y especialmente, a la posibilidad de sintetizar múltiples ligandos orgánicos permite diseñar químicamente materiales con propiedades “a la carta”, además de la posibilidad de presentar multifuncionalidad, esto es, la combinación de diver…
Inverted molecular cups: 1-D and 2-D Ag(I) coordination polymers from resorcinarene bis-thiacrowns
2016
Resorcinarene bis-thiacrown hosts 1–3 were prepared and crystallized with silver trifluoroacetate yielding one and two dimensional Ag coordination polymers. The complexation of silver in exo-cavity fashion folds the thiacrown bridges inwards transforming the resorcinarene hosts into inverted molecular cups. The silver cations were coordinated to the resorcinarene ligands and trifluoroacetate anions, which act as monodentate or bidendate bridging ligands between the metal ions. Argentophilic Ag···Ag (2.93–3.38 Å) interactions supported by two bridging carboxylate anions were found in two of the structures, whereas longer Ag···Ag distances were observed if only one anion connected the silver …
Magnetic materials based on coordination chemistry: from switching molecules to multifunctional magnets
2021
Esta tesis tiene como objetivo principal la preparación de materiales moleculares multifuncionales magnéticos. Para ello se han usado dos estrategias diferentes: una aproximación iónica, en la que se han preparado sales de cationes funcionales y se han combinado con redes aniónicas extendidas (capítulos 2 y 3); y la segunda estrategia, donde, a través de enlaces covalentes entre ligandos funcionales y fulerenos (capitulo 4), o polioxometalatos (capítulo 5) se han obtenido sistemas que presentan la propiedad de transición de espín con efectos sinérgicos. En el capítulo 2 se presenta la síntesis y caracterización de varios polímeros de coordinación basados en el ligando anilato con cationes i…
Hybrid magnetic materials based on coordination chemistry: from switching magnetic molecules to 2D coordination polymers
2015
El trabajo descrito en esta tesis se encuadra en el ámbito de los materiales moleculares. Presenta varias estrategias para preparar nuevos materiales híbridos multifuncionales. Los complejos de transición de espín (SCO) constituyen uno de los ejemplos más espectaculares de biestabilidad molecular. En estos sistemas, las transiciones entre los estados de bajo espín (LS) y alto espín (HS) pueden estar inducidos por una variedad de estímulos externos (temperatura, presión o radiación electromagnética). Además de los interesantes aspectos fundamentales, este fenómeno es de interés creciente en el área de los materiales funcionales debido a las posibles aplicaciones en sensores, memorias o dispo…
Copolymerization of Vinylidene Fluoride and Acrylic Acid in Supercritical Carbon Dioxide
2010
The free-radical copolymerization of vinylidene fluoride (VDF) and acrylic acid (AA) was carried out in supercritical carbon dioxide using both precipitation and dispersion techniques in the presence of an ammonium carboxylate perfluoropolyether compound. Formation of a copolymer was confirmed by variable contact time CP MAS NMR spectroscopy. Macromolecular matrices were significantly enriched in AA with respect to the initial feed composition and we found that the nonfluorinated monomer has a much higher reactivity ratio with respect to VDF. The cumulative concentration, crystallinity, and water affinity of the synthesized copolymers could be modified changing the initial feed composition,…
Crystal structure of 4-{2-[4-(dimethylamino)phenyl]diazen-1-yl}-1-methylpyridinium iodide
2015
The molecular geometry of the ionic title compound, C14H17N4+·I−or DAZOP+·I−, is essentially featureless. Regarding the crystal structure, in addition to the obvious cation–anion Coulombic interactions, the packing is mostly directed by non-covalent interactions involving both ring systems, as well as the iodide anion. It consists of cationic molecules aligned along [101] and disposed in an antiparallel fashion while linked into π-bonded dimeric entities by a stacking contact involving symmetry-related phenyl rings, with a centroid–centroid distance of 3.468 (3) Å and a slippage of 0.951 Å. The dimers are, in addition, sustained by a number of C—H...I and I...π (I...centroid = 3.876 Å) inte…