Search results for "IAM"
showing 10 items of 2521 documents
Quimiosensores y quimiodosímetros para la detección de neurotransmisores
2019
La presente Tesis Doctoral titulada “Quimiosensores y quimiodosímetros para la detección de neurotransmisores” está centrada en el desarrollo de nuevos sistemas para la detección cromogénica y fluorogénica de moléculas biógenas, haciendo especial hincapié en el uso del fenómeno conocido como Emisión Inducida por Agregación (AIE) como mecanismo de transducción. Para ello, se han sintetizado y estudiado una serie de derivados del tetrafenileteno (TPE), compuesto que presenta propiedades AIE que pueden ser modificadas fácilmente gracias a la adecuada funcionalización del mismo. En el capítulo 3 se describe cómo, en derivados del TPE funcionalizados con anillos de triazol sustituidos con cadena…
Ferromagnetic coupled μ-phenoxo-μ-carboxylato heterodinuclear complexes based on the Cr(salen) moiety: Structural and magnetic characterization
2009
The synthesis, crystal structure, and magneto-chemical characterization of two new unprecedented μ-phenoxo-μ-carboxylato heterodinuclear complexes based on the Cr(salen) moiety (salen = N,N′-bis(salicylidene)ethylenediamine), [MII(O2C(CH3)3)(OH2)2(μ-O2C(CH3)3)(μ-salen)CrIII(O2C(CH3)3)], M = Ni (2), Co(3) are reported. The dinuclear complexes were obtained starting from the mononuclear trans-[Cr(salen)(CN)2]PPh4 (1), whose crystal structure is also reported. They show a trans arrangement of the Cr(salen) unit, bridging through the phenolate O atoms to a second metal center. An additional μ2-O2-carboxylato bridge and a further monodentating carboxylate ligand complete the roughly octahedral C…
Stabilized Naked Sub-nanometric Cu Clusters within a Polymeric Film Catalyze C-N, C-C, C-O, C-S, and C-P Bond-Forming Reactions
2015
[EN] Sub-nanometric Cu clusters formed by endogenous reduction of Cu salts and Cu nanoparticles are active and selective catalysts for C−N, C−C, C−O, C−S, and C−P bond-forming reactions. Sub-nanometric Cu clusters have also been generated within a polymeric film and stored with full stability for months. In this way, they are ready to be used on demand and maintain high activity (TONs up to 104 ) and selectivity for the above reactions. A potential mechanism for the formation of the sub-nanometric clusters and their electronic nature is presented.
DNA-binding of zinc(II) and nickel(II) salphen-like complexes extrapolated at 1 M salt concentration: Removing the ionic strength bias in physiologic…
2020
Abstract The DNA-binding of two salphen-like metal complexes of nickel(II) (1) and zinc(II) (2) was investigated in different ionic strength solutions by absorption spectroscopy. The data analysis allowed us to obtain the values of their extrapolated DNA-binding constant in physiological conditions, with DNA-binding strength in the order Ni > Zn, and to give relative weight to the electrostatic and non-electrostatic contributions to their DNA-interaction.
Channeling experiments at planar diamond and silicon single crystals with electrons from the Mainz Microtron MAMI
2020
Line structures were observed for (110) planar channeling of electrons in a diamond single crystal even at a beam energy of 180 MeV . This observation motivated us to initiate dechanneling length measurements as function of the beam energy since the occupation of quantum states in the channeling potential is expected to enhance the dechanneling length. High energy loss signals, generated as a result of emission of a bremsstrahlung photon with about half the beam energy at channeling of 450 and 855 MeV electrons, were measured as function of the crystal thickness. The analysis required additional assumptions which were extracted from the numerical solution of the Fokker-Planck equation. Prel…
Gaia -ESO Survey: Analysis of pre-main sequence stellar spectra
2015
This paper describes the analysis of UVES and GIRAFFE spectra acquired by the Gaia-ESO Public Spectroscopic Survey in the fields of young clusters whose population includes pre-main sequence (PMS) stars. Both methods that have been extensively used in the past and new ones developed in the contest of the Gaia-ESO survey enterprise are available and used. The internal precision of these quantities is estimated by inter-comparing the results obtained by such different methods, while the accuracy is estimated by comparison with independent external data, like effective temperature and surface gravity derived from angular diameter measurements, on a sample of benchmarks stars. Specific strategi…
Purification and characterization of the catabolic ?-acetolactate synthase from Leuconostoc mesenteroides subsp. cremoris
1995
The α-acetolactate synthase from Leuconostoc mesenteroides subsp. cremoris was purified to homogeneity in SDS-PAGE. The enzyme is a trimer of 3×55,000 Da. It was unstable but could be preserved by addition of pyruvate and thiamine pyrophosphate in the buffer. The enzyme exhibits Michaelis-Menten kinetics, and Km for pyruvate is 10 mM. Three intermediates in glucose metabolism (ATP, 3-phosphoglycerate, and phosphoenolpyruvate) exhibit a noncompetitive inhibition towards the enzyme. This enzyme does not require any divalent metal ion for activity. The α-acetolactate synthase from Leuconostoc mesenteroides subsp. cremoris is not inhibited by the branched-chain amino acids (valine, leucine, and…
Impact of viewing distance on relative depth judgements for stimuli in physical space
2019
In natural viewing, numerous depth cues are available to the visual system, but their significance varies considerably depending on the viewing distance. How is it reflected in the outcome of depth judgements? We have designed a psychophysical experiment with a limited number of depth cues to examine distance-related changes in the correct response rate and time. Twenty young adults evaluated relative depth of stimuli in physical space. Each time four constant angular size achromatic stimuli were presented on a volumetric multi-planar display. One of these stimuli was demonstrated closer to the observer comparing to others. The experiment followed the four-interval forced-choice procedure. …
Chemical initiation for butyl and lauryl acrylate monolithic columns for CEC.
2009
Butyl acrylate (BA)- and lauryl acrylate (LA)-based monolithic stationary phases for CEC were synthesized, using a redox system as initiator of polymerization. BA monoliths were initiated with ammonium peroxodisulfate, whereas LA columns were obtained with lauroyl peroxide as initiator. In both cases, TEMED was used to activate the process. The influence of porogenic solvent composition on both morphological and electrochromatographic properties of the resulting monoliths was investigated. Excellent efficiencies (minimum plate heights of 4.2-6.3 microm for BA columns and 2.6-5.3 microm for LA stationary phases, for a PAHs mixture) were achieved. The capability of separation of both types of…
A new sample of large angular size radio galaxies
2004
We present in this paper a detailed study of a new sample of large angular size FR I and FR II radio galaxies and compare the properties of the two classes. As expected, a pure morphology based distinction of FR Is and FR IIs corresponds to a break in total radio power. The radio cores in FR Is are also weaker than in FR IIs, although there is not a well defined break power. We find that asymmetry in the structure of the sample members must be the consequence of anisotropies in the medium where the lobes expand, with orientation playing a minor role. Moreover, literature data and our observations at kiloparsec scales suggest that the large differences between the structures of FR I and FR I…