51 research outputs found
Primers avánços sobre el conjunt terrisser de Ripoll de Can Brunet (Òdena, Anoia)
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN008121 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Dynamical generation of a gauge symmetry in the Double-Exchange model
It is shown that a bosonic formulation of the double-exchange model, one of the classical models for magnetism, generates dynamically a gauge-invariant phase in a finite region of the phase diagram. We use analytical methods, Monte Carlo simulations and Finite-Size Scaling analysis. We study the transition line between that region and the paramagnetic phase. The numerical results show that this transition line belongs to the Universality Class of the Antiferromagnetic RP(2) model. The fact that one can define a Universality Class for the Antiferromagnetic RP(2) model, different from the one of the O(N) models, is puzzling and somehow contradicts naive expectations about Universality
Diseño de radiocomunicación de CanSat didáctico
Se presenta el cálculo del diseño de radiocomunicación punto a punto de un satélite didáctico entre los módulos zigbee; el receptor de la estación terrena que colecta los datos de telemetría (orientación en tres ejes, giroscopio, geoposicionamiento, humedad y presión barométrica) con una sensibilidad de -100 dB y una potencia isotrópica radiada efectiva de 17.6 dBmW por el transmisor contenido en el módulo de comunicaciones del satélite incrustado en una lata de aluminio (CanSat), con un peso total de 355 g, suspendido a una distancia de un kilómetro sobre el nivel del suelo. El diseño considera la distancia, ganancias de antenas, potencia del transmisor y umbral del receptor, las pérdidas por desvanecimiento, permitiendo observar el margen de desvanecimiento y del sistema.Palabra(s) Clave(s): CanSat, punto a punto, satélite, telemetría, zigbee
Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019
Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population
Absorción de petróleo crudo, diésel y aceite automotriz gastado por residuos lignocelulósicos y su aplicación como sistema de disposición de hidrocarburos
Elaboración y caracterización de películas delgadas de óxido de aluminio: propiedades ópticas, estructurales y eléctricas
Tesis (Maestría en Tecnología Avanzada), Instituto Politécnico Nacional, CICATA, Unidad Legaria, 2008, 1 archivo PDF, (112 páginas). tesis.ipn.m
Estudio de automedicación en una farmacia comunitaria de la ciudad de Toluca
El objetivo de este trabajo fue realizar un estudio en una farmacia comunitaria de la ciudad de Toluca, para determinar la frecuencia y los factores que predisponen a la automedicación en la población. Mediante un estudio descriptivo, observacional y prospectivo, se analizaron las adquisiciones de medicamentos en la farmacia. El instrumento de recolección de datos fue un cuestionario, que refería información de características sociodemográficas, económicas, cobertura del sistema sanitario y de automedicación. Los resultados mostraron un mayor porcentaje de automedicación en: mujeres, población adulta y en sujetos con menor acceso a servicios sanitarios. Los medicamentos que más se consumieron fueron: analgésicos, antibióticos y antiácidos. Con este estudio se determinaron los grupos prioritarios a los que se deben dirigir programas de educación sanitaria, para mejorar la calidad de la automedicación
En route to chiral-at-metal ruthenium complexes containing tripodal tetradentate ligands
Synthetic routes for ruthenium(II) complexes bearing the {Ru(κ4C,N,N′,P-L)} fragment (L = tripodal tetradentate ligand) are explored. Tripodal ligands LH1–LH3 diastereoselectively react with the dimer [{(Cy)RuCl}2(μ-Cl)2] (Cy = η6-p-MeC6H4iPr), affording the p-cymene compounds [(Cy)Ru(κ3N,N′,P-LH)][SbF6] (1–3). Refluxing complexes 1–3 in MeCN gives [Ru(κ3N,N′,P-LH)(NCMe)3][SbF6]2 (4a–6a). In refluxing MeOH, isomers 4a–6a evolve to the corresponding mer complexes 4c–6c. Reaction of [RuCl2(PPh3)3] with LH1 affords [RuCl2(PPh3)(κ3N,N′,P-LH1)] (7) as only one isomer. [RuClH(CO)(PPh3)3] reacts with ligands LH1–LH3 to give [RuH(CO)(PPh3)(κ3N,N′,P-LH)]Cl (8–10). Complexes 8–10 were isolated as a mixture of only two diastereomers as pairs of enantiomers. Refluxing suspensions of complexes 8–10 in 2-ethoxyethanol afforded the corresponding metalated complexes [RuCl(CO)(κ4C,N,N′,P-L)] (11–13), in which the tripodal ligands L1–L3 act as tetradentate ligands. Only one stereoisomer was detected for complexes 11 and 13, but metalation at the C-2 or C-6 carbons gave a mixture of two isomers for complex 12. The new complexes have been characterized by analytical and spectroscopic means and by the determination of the crystal structures of the complexes 1, 2, 5c, 10a, 11a, 12a,b, and 13a by X-ray diffractometry.We thank the Ministerio de Economía y Competitividad of Spain (Project CTQ2015-66079-P) and Gobierno de Aragón (Grupo Consolidado: Catalizadores Organometalicos Enantioselectivos) for financial support. R.R. acknowledges the Ministerio de Economía y Competitividad of Spain for a
Ramon y Cajal (RYC-2013-13800) grant. P.G.-O. acknowledges the CSIC and European Social Fund for a PTA contract.Peer reviewe
Changes in Sugar Sweetened Beverage Intake Are Associated with Changes in Body Composition in Mexican Adolescents: Findings from the ELEMENT Cohort
Changes in consumption of sugar sweetened beverage (SSBs) have been associated with increased body mass index (BMI), but little work has evaluated the effect on waist circumference (WC) and body fat percentage during adolescence, a period characterized by rapid growth and change in dietary behaviors. We examined the relationship of changes in SSB intake and changes in adiposity over two years in 464 Mexican adolescents. Food frequency questionnaires were used to sum intake of regular soda, coffee with sugar, tea with sugar, sweetened water with fruit, chocolate milk, corn atole, and a sweetened probiotic milk beverage. Linear regression models were used to estimate the associations of changes in SSBs with changes in BMI, body fat percentage, and WC, adjusting for sex, socioeconomic status, screen time, physical activity, age, and change in age. Adolescents who increased their daily SSB intake by >2 serving had a −2.72% higher body fat percentage (95% CI: 0.61, 4.82); a 1–2 serving increase was associated with a 2.49 cm increase (95% CI: 0.21, 4.76) in WC compared with those with no change in intake. Within an adolescent sample, changes in SSB intake were related to concomitant changes in body fat percentage and WC, but not BMI
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