Search results for "abs"
showing 10 items of 6504 documents
Innovative in vitro method and permeability estimation procedure to predict drug transport across the blood-brain barrier
2014
La Barrera Hematoencefálica (BHE) es una entidad caracterizada por su naturaleza restrictiva al paso de sustancias. Las propiedades de la barrera están determinadas por la confluencia de tres componentes principales: 1) uniones celulares endoteliales con presencia de proteínas especificas intramembrana y citoplasmáticas unidas estrechamente al citoesqueleto. Esta circunstancia restringe la difusión paracelular de compuestos. Adicionalmente a las células endoteliales, la barrera presenta una membrana basal, en la cual se localizan pericitos y astrocitos, que conforman una capa que refuerza las propiedades de la barrera; 2) la presencia de transportadores de absorción y la sobreexpresión de t…
A dual channel sulphur-containing a macrocycle functionalised BODIPY probe for the detection of Hg(II) in a mixed aqueous solution
2018
We report herein the synthesis and chromo-fluorogenic behaviour of a new probe 1 containing a boron-dipirromethene (BODIPY) unit electronically connected with a dithia-dioxa-aza macrocycle. Acetonitrile and water-acetonitrile 95:5 v/v solutions of the probe showed an ICT band in the visible zone and are nearly non-emissive. When acetonitrile was used as solvent, addition of Hg(II) and trivalent metal cations induced an hypsochromic shift of the absorption band and moderate emission enhancements. A highly selective response was obtained when using competitive media such as wateracetonitrile 95:5 v/v. In this case only Hg(II) induced a hypsochromic shift of the absorption band and a marked em…
Investigación de la estructura electrónica de láminas delgadas, pozos cuánticos y nanopartículas de Zn1-xCoxO mediante medidas ópticas y de transport…
2014
Dietl et al. Predijeron un comportamiento ferromagnético (FM) en compuestos de semiconductores magnéticos diluidos (DMS) de gap ancho como Ga1-xMnxN o Zn1-xCoxO. Las láminas delgadas de alta calidad basadas en los DMs de ZnO son de especial interés debido al bajo coste y la estabilidad del material. De esta manera, varios grupos han presentado que el comportamiento ferromagnético del Zn1-xCoxO a temperatura ambiente se debe a la existencia de diferentes fases o a agrupamientos pequeños de cobalto, especialmente para altas concentraciones de Co. De acuerdo con trabajos anteriores sobre el (Zn,Co)O , la transición de la fase wurtzita a la fase rock-salt en el material masivo y en las láminas …
Perfil neuropsicológico de alcohólicos con alta densidad familiar de alcoholismo tras abstinencia prolongada: hallazgos preliminares
2002
INTRODUCCIÓN: Los estudios que han analizado el funcionamiento cognitivo de sujetos alcohólicos en función de la historia familiar de alcoholismo (11F+) han obteni¬do resultados poco consistentes, debido quizá a que el efecto de este factor puede verse oscurecido por la neurotoxicidad del alcohol. Esto puede evitarse comparando a los sujetos una vez que han abandonado el consumo de la sustancia. OBJETIVO: Determinar el perfil neuropsicológico de alcohólicos HF+ con más de tres años de abstinencia, con el fin de valorar la existencia y, en su caso, naturaleza de la afectación neuropsicológica. MATERIALY MÉTODOS: La muestra está formada por un grupo de sujetos alcohólicos abstinentes con al m…
Two cases of monomicrobial intraabdominal abscesses due to KPC - 3 Klebsiella pneumoniaeST258 clone
2011
Abstract Background Knowledge of the etiology of pyogenic liver and pancreatic abscesses is an important factor in determining the success of combined surgical and antibiotic treatment. Literature shows geographical variations in the prevalence and distribution of causative organisms, and the spread of Klebsiella pneumoniae carbapenemase-producing bacteria is an emerging cause of abdominal infections. Case presentation We herein describe two cases of intra-abdominal abscesses due to monomicrobial infection by Klebsiella pneumoniae Sequence Type 258 producing K. pneumoniae carbapenemase 3 (KPC-Kp). In case 1, a 50-year-old HIV-negative Italian woman with chronic pancreatitis showed infection…
Humusvielu izcelsmes – īpašību izpēte izmantojot to multiparametru raksturojumu
2019
Humusvielu izcelsmes-īpašību izpēte izmantojot to multiparametru raksturojumu. Upska K., zinātniskais vadītājs prof., Dr. habil. chem. Kļaviņš M. prof. Dr.chem. Vīksna A. un, Kursa darbs, 62 lappuses, 22 attēli, 11 tabulas, 37 literatūras avoti, 2 pielikumi. Latviešu valodā. Bakalaura darbā tika apkopota zinātniskā literatūra par humusvielām, to izcelsmi, funkcijām biosfērā, ražošanas, izdalīšanas un pētīšanas metodēm. Tika noteikts humusvielu organiskais un neorganiskais elementsastāvs, kas sniedz informāciju par rūpnieciski ražotu humusvielas produktu kvalitāti. Izmantojot UV-Vis un FTIR molekulārās absorbcijas metodi tika uzņemti un analizēti humusvielu absorbcijas spektri. Izmantojot fl…
Negative thermal expansion in cuprite-type compounds: A combined synchrotron XRPD, EXAFS, and computational study of Cu2O and Ag2O
2006
Cuprite-type oxides (Cu2O and Ag2O) are framework structures composed by two interpenetrated networks of metal-sharing M4O tetrahedra (M = Cu, Ag). Both compounds exhibit a peculiar negative thermal expansion (NTE) behaviour over an extended temperature range (9 240 K for Cu2O, 30-470 K for Ag2O). High-accuracy synchrotron powder diffraction and EXAFS measurements were performed from 10 K up to the decomposition temperature to understand the nature of the NTE effects. The critical comparison of the diffraction and absorption results concerning the temperature dependence of the interatomic distances and of the atomic vibrational parameters proves to be fundamental in defining the local dynam…
Multiple scattering approach for two-electron resonant emission studied by angle-resolved coincidence spectroscopy.
2008
International audience; We have developed a generalization of the multiple-scattering formalism to deal with Auger-photoelectron coincidence spectroscopy APECS in the solid state. We have merged the exact atomic treatment of the angular correlations between the two electrons and the single-particle approach, on which the multiplescattering description of condensed matter relies. This allows the recovering, even in extended systems, of the entangled form of the electron-pair wave function characterizing the coincidence angular diffraction pattern. In the atomic limit our formalism correctly reproduces the cross section, as calculated within the statistical-tensors approach, usually employed …
Decorated pottery study: Analysis of pigments by x-ray absorbance spectroscopy measurements
2007
Characterization of pigments on decorated pottery fragments has been fully carried out by nondestructive x-ray absorbance spectroscopy (XAS). The samples were a series of pottery shards excavated from the archeological site of Caltagirone (Sicily, Italy), a well-known ceramic production center. Aesthetical criteria and morphological observations allowed us to attribute the samples to quite different historical periods, starting from the 18th century B.C. up to the 16th century A.D. An extensive time interval led us to suppose that different materials and techniques were used for the production of the ceramic paste and also for the preparation of pigments. XAS measurements were performed at …
Improved bioaccessibility and antioxidant capacity of olive leaf ( Olea europaea L.) polyphenols through biosorption on Saccharomyces cerevisiae
2016
Abstract Olive ( Olea europaea L.) leaves (OL) are natural by-products that can be used as an advantageous rich source of bioactive compounds, especially polyphenols. This study investigated the potential use of Saccharomyces cerevisiae as a new carrier of OL antioxidants and a means to protect their bioactivity during simulated gastrointestinal digestion. The biosorption on S. cerevisiae allowed the recovery of 25.17 mg/g and 49.40% of the polyphenols from olive leaf (var. Chemlali ) infusions. Both infusions and suspensions before and after biosorption were analyzed for total soluble polyphenols and total antioxidant capacity (oxygen radical absorbance capacity (ORAC) and trolox equivalen…