Search results for "solu"
showing 10 items of 7577 documents
Conformational investigation of α,β‐dehydropeptides. XV: N‐acetyl‐α,β‐dehydroamino acid N ′N ′‐dimethylamides: conformational properties from infrare…
2005
The FTIR spectra were analysed in the region of the nu(s)(N-H), AI(C=O) and nu(s)(Calpha=Cbeta) bands for a series of Ac-DeltaXaa-NMe2, where DeltaXaa = DeltaAla, (Z)-DeltaAbu, (Z)-DeltaLeu, (Z)-DeltaPhe and DeltaVal, to determine a predominant solution conformation of these alpha,beta-dehydropeptide-related molecules. Measurements were taken in CCl4, DCM and MeCN solutions. In the same way, spectra of saturated analogues Ac-Xaa-NMe2, where Xaa = Ala, Abu, Leu, Phe and Val, were investigated. To help interpret the spectroscopic results, conformational maps were calculated by the B3LYP/6-31+G** method. Also, the relative energies of all conformers of the dehydro compounds in vacuo as well as…
La transposición de la Directiva (UE) 2019/771 al ordenamiento jurídico español: falta de conformidad, remedios y plazos
2022
El Real Decreto- Ley 7/2021, de 27 de abril, ha transpuesto en el Texto Refundido de la Ley General para la Defensa de los Consumidores y Usuarios la Directiva (UE) 2019/770 y la Directiva (UE) 2019/771. Esta nueva normativa que se establece en el TRLGDCU entrará en vigor el 1 de enero de 2022. Y por ello, lo que se pretende con este breve artículo, siempre desde la perspectiva de la compraventa de bienes, es realizar una exposición de las novedades introducidas en el régimen de garantías y, en concreto, lo relativo a la conformidad de los bienes, medidas correctoras por falta de conformidad y plazos.
Methionine in a protein hydrophobic core drives tight interactions required for assembly of spider silk
2019
Web spiders connect silk proteins, so-called spidroins, into fibers of extraordinary toughness. The spidroin N-terminal domain (NTD) plays a pivotal role in this process: it polymerizes spidroins through a complex mechanism of dimerization. Here we analyze sequences of spidroin NTDs and find an unusually high content of the amino acid methionine. We simultaneously mutate all methionines present in the hydrophobic core of a spidroin NTD from a nursery web spider’s dragline silk to leucine. The mutated NTD is strongly stabilized and folds at the theoretical speed limit. The structure of the mutant is preserved, yet its ability to dimerize is substantially impaired. We find that side chains of…
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…
Els epítets dels artistes baixmedievals al servei dels poders reial i municipal
2021
Aquest article estudia els adjectius que van rebre els artistes que treballaren per al rei i per a les elits ciutadanes en els territoris de parla catalana durant els segles XIV i XV. En particular, se n’hi examinen dos: apte i subtil. Les notícies exhumades per uns altres especialistes fins al moment permeten comprendre’ls en el propi context documental. Ací es compara el seu significat amb uns altres exemples de la literatura baixmedieval de la Corona d’Aragó i es du a terme una aproximació històrica com a paraules que al·ludien a la perícia de l’artista i que van ser escollides amb una finalitat. Participaren i repercutiren, per tant, en la relació històrica de l’artista amb el client, …
Alternative Dispute Resolution Systems Across the European Union, Iceland and Norway
2014
Abstract Alternative dispute resolution schemes (ADR) have been developed differently across the EU. It is difficult to determine which of the countries have developed the most successful schemes. Therefore the aim of this article is to summarize different organizational aspects of ADR schemes across the EU, to determine similarities across different countries and to define them in specific systems. Defining these schemes in systems will not only help to evaluate and compare ADR schemes and their success between different countries but will help also professionals, governments and other stakeholders to develop more effective ADR schemes across the EU, Iceland and Norway.
Las medidas correctoras en el ámbito digital
2022
Ante el aumento de la producción y el intercambio de los contenidos y servicios digitales como consecuencia de la evolución de las nuevas tecnologías, se hace necesario establecer un marco jurídico que dote de protección a los consumidores y usuarios. En este sentido, el Real Decreto Ley 7/2021, de 27 de abril, transpuso en el Texto Refundido de la Ley General para la Defensa de los Consumidores y Usuarios (TRLGDCU) la Directiva 2019/770, sobre contratos de suministro de contenidos y servicios digitales. Se examinan aquí las medidas correctoras de las que dispone el consumidor o usuario ante una falta de conformidad de los contenidos o servicios digitales o ante un incumplimiento contractua…
On the synthesis of functionalized porphyrins and porphyrin conjugates via β-aminoporphyrins
2016
International audience; The synthesis of functionalized porphyrins and their conjugates from meso-tetraarylporphyrins through the acylation and the oxidation of beta-aminoporphyrins was investigated. 2,3-Dioxochlorins were prepared by the oxidation of a variety of beta-aminoporphyrins and subsequently used in a condensation reaction with functionalized aromatic aldehydes and ammonium acetate to form beta-functionalized porphyrins bearing a fused imidazole ring. Under optimized experimental conditions both reactions tolerate various functional groups and afford the products in an appropriate overall yield. The mildness and usefulness of this methodology are illustrated by several examples in…
Gallium(III) and Indium(III) Complexes with meso-Monophosphorylated Porphyrins: Synthesis and Structure. A First Example of Dimers Formed by the Self…
2017
International audience; The synthesis and structural characterization, both in solution by means of H-1 and P-31 NMR and UV-vis spectroscopies and in the solid state by X-ray diffraction on single crystal, of a series of gallium(III) and indium(III) meso-mono(diethoxyphosphoryl)porphyrins bearing different peripheral substituents as well as the corresponding monoesters and phosphonic acids are reported. This work describes the first example of the X-ray structure of a self-assembled dimer formed via strong binding between the oxygen atom of the phosphonate substituent and the gallium(III) cations of adjacent porphyrin molecules [Ga-O = 1.9708(13) angstrom].
Copper Octacarboxyphthalocyanine Aggregation in Buffered Solutions
2008
Results of spectral UV-Vis absorption investigations on association of copper octa-carboxyphthalocyanine, CuPcOC, are reported. Influence of pH on association is discussed. In pH < 5.5 only ag gre gates are present. Monomer appears above pH = 5.5 and at pH Greater-than or equal to 6.2 only monomeric Pc forms exist. CuPcOC exhibits higher tendency to wards association in phosphate buffer solutions than in redistilled water. In pH 5.9–6.0 monomers, dimers and trimers coexist in equilibrium in 1.0×10–6 – 1.2×10–5 mol/dm3 concentration range at 25°C. The average assembling number n = 3 was determined for pH 5.6, 5.9 and 6.0 solutions. The spectrum of aggregate was calculated with two maxima at …