Search results for "CA [MG]"
showing 10 items of 2161 documents
Crystal and solution structures of di-n-butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: E…
2009
Abstract Reactions of nBu2SnCl(L1) (1), where L1 = acid residue of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol, with various substituted benzoic acids in refluxing toluene, in the presence of triethylamine, yielded dimeric mixed ligand di-n-butyltin(IV) complexes of composition [nBu2Sn(L1)(L2–6)]2 where L2 = benzene carboxylate (2), L3 = 2-[(E)-2-(2-hydroxy-5-methylphenyl)-1-diazenyl]benzoate (3), L4 = 5-[(E)-2-(4-methylphenyl)-1-diazenyl]-2-hydroxybenzoate (4), L5 = 2-{(E)-4-hydroxy-3-[(E)-4-chlorophenyliminomethyl]-phenyldiazenyl}benzoate (5) and L6 = 2-[(E)-(3-formyl-4-hydroxyphenyl)-diazenyl]benzoate (6). All complexes (1–6) have been characterized by elemental analyses, IR, 1H,…
Preparation and structural characterization of organotin(IV) complexes with ligands containing a hetero {N} atom and a hydroxy group or hydroxy and c…
2005
AbstractTwenty-two n-butyltin(IV) and t-butyltin(IV) complexes of ligands containing an –OH (–C@O) group or –OH and –COOHgroups and an aromatic {N} donor atom were prepared by metathetical reactions. On the basis of the FT-IR and Mo¨ssbauer spec-troscopic data, molecular structures were assigned to these compounds. The binding sites of the ligands were identified by means ofFT-IR spectroscopic measurements, and it was found that in most cases the organotin(IV) moiety reacts with the phenolic form ofthese ligands. In the complexes with –OH and –COOH functions, the –COOH group is coordinated to the organotin(IV) centres in amonodentate manner. The 119 Sn Mo¨ssbauer and the FT-IR studies suppor…
Keggin heteropolyacid supported on BN and C3N4: Comparison between catalytic and photocatalytic alcohol dehydration
2020
The Keggin heteropolyacid (HPA), H3PW12O40 (PW12) has been supported on commercial boron nitride (BN) and two types of home prepared carbon nitride (C3N4). The supported PW12 was used in the gas-solid (photo)catalytic 2-propanol dehydration reaction to give propene at atmospheric pressure and temperatures in the range 70–120 °C and resulted more active than the pristine PW12. Reaction rate increased by increasing the temperature. Noticeably, the propene formation rate was higher by irradiating the catalytic system. The PW12/BN material resulted more active than PW12/C3N4. The acidity of the HPA cluster accounts for the catalytic role, whereas both the acidity and the redox properties of the…
Impact on Air Quality of the COVID-19 Lockdown in the Urban Area of Palermo (Italy).
2020
At the end of 2019, the first cases of coronavirus disease (COVID-19) were reported in Wuhan, China. Thereafter, the number of infected people increased rapidly, and the outbreak turned into a national crisis, with infected individuals all over the country. The COVID-19 global pandemic produced extreme changes in human behavior that affected air quality. Human mobility and production activities decreased significantly, and many regions recorded significant reductions in air pollution. The goal of our investigation was to evaluate the impact of the COVID-19 lockdown on the concentrations of the main air pollutants in the urban area of Palermo (Italy). In this study, the trends in the average…
Design and implementation of PET detectors based on monolithic crystals and SiPMs
2018
Esta tesis doctoral se centra tanto en el diseño como en la validación experimental de detectores de rayos gamma para escáneres de tomografía por emisión de positrones (PET, del inglés Positron Emission Tomography). El objetivo principal de esta tesis es el diseño de innovadores bloques detectores PET de alto rendimiento. La técnica PET constituye una de las principales herramientas diagnósticas en medicina nuclear, que es una especialidad médica que utiliza sustancias radiactivas con fines diagnósticos y terapéuticos. Esta técnica de imagen médica permite visualizar procesos fisiológicos y bioquímicos del cuerpo humano in vivo, mediante la administración del elemento radiotrazador. Los rad…
Structure of locally convex quasi C * -algebras
2008
There are examples of C*-algebras A that accept a locally convex *-topology τ coarser than the given one, such that Ã[τ] (the completion of A with respect to τ) is a GB*-algebra. The multiplication of A[τ] may be or not be jointly continuous. In the second case, Ã[*] may fail being a locally convex *-algebra, but it is a partial *-algebra. In both cases the structure and the representation theory of Ã[τ] are investigated. If Ã+ τ denotes the τ-closure of the positive cone A+ of the given C*-algebra A, then the property Ā+ τ ∩ (-Ā+ τ) = {0} is decisive for the existence of certain faithful *-representations of the corresponding *-algebra Ã[τ]
Field rules and bias in random surveys with quota samples : an assessment of CIS surveys
2018
Surveys applying quota sampling in their final step are widely used in opinion and market research all over the world. This is also the case in Spain, where the surveys carried out by CIS (a public institution for sociological research supported by the government) have become a point of reference. The rules used by CIS to select individuals within quotas, however, could be improved as they lead to biases in age distributions. Analysing more than 545,000 responses collected in the 220 monthly barometers conducted between 1997 and 2016 by CIS, we compare the empirical distributions of the barometers with the expected distributions from the sample design and/or target populations. Among other …
Mujer y representación política institucional en la Comunidad Valenciana. 1977-1995. Diputadas, ministras y cargos institucionales
2014
“Mujer y representación política institucional en la Comunidad Valenciana. 1977-1995. Diputadas, ministras y cargos institucionales” es la primera parte de un trabajo de documentación para un capítulo de “La democracia en la Comunidad Valenciana. Partidos, elites políticas, elecciones y programas políticos”. “Mujer, poder político y democracia paritaria”. Se recoge el papel de la mujer en la vida política de la Comunidad Valenciana en la democracia actual, desde 1977. Es documentación sin elaborar, pero que aporta datos de la presencia de la mujer en las instituciones, partidos y sindicatos. Cuando este completa será una parte de la investigación referida, y de la que ya hay dos publicacion…
Caracterización genética y molecular de la familia fosfoglicerato quinasa de Arabidopsis thaliana
2016
La glicólisis fue la primera gran ruta metabólica dilucidada, a nivel bioquímico, alrededor de los años 40 del siglo XX. Sin embargo, la existencia en plantas tanto de dos rutas glicolíticas, que actúan en paralelo en el citosol y los plastos, como de varias isoformas para cada enzima, y la presencia de células autótrofas y heterótrofas, donde la glicólisis puede realizar funciones completamente distintas, ha complicado su comprensión. En los últimos años se ha realizado un gran esfuerzo para caracterizar, funcionalmente, las enzimas de las dos rutas glicolíticas de las plantas, mediante aproximaciones genéticas y moleculares. En esta tesis doctoral se ha caracterizado, funcionalmente, la f…
Estudio de alteraciones neurofisiológicas durante el sueño en pacientes con encefalopatía hepática mínima
2021
Una proporción importante de los pacientes con cirrosis y otras enfermedades hepáticas van a desarrollar una afectación del sistema nervioso central en forma de encefalopatía hepática. En fases iniciales, la clínica puede pasar desapercibida, estadio que da lugar al concepto de encefalopatía hepática mínima (EHM), que es habitualmente diagnosticada mediante test neuropsicológicos. Las alteraciones del sueño pueden ser las primeras manifestaciones neurológicas de la EHM y se asocian con una disminución de la calidad de vida. Existe un interés en la obtención de biomarcadores que permitan identificar a estos pacientes para su tratamiento precoz. La hipótesis del estudio parte de si la polisom…