10 research outputs found
Seville City Hall Chapter Room ceiling decoration
El objetivo de este trabajo es el estudio de diferentes aspectos, como el color, la composición química y las fases mineralógicas presentes en los diferentes materiales que forman la ornamentación del techo de la Sala Capitular del Ayuntamiento de Sevilla, mediante métodos físicos y químicos. Nuestros resultados muestran que el dorado fue realizado sobre una capa de bol previamente depositada sobre una lámina de blanco de plomo que cubría un estrato de calcita. Posteriormente, y probablemente debido a alteraciones en el dorado original, el techo fue de nuevo dorado usando una técnica similar. En el siglo XIX, casi todo el techo, excepto las zonas con inscripciones, fue blanqueado usando una mezcla de calcita y blanco de plomo. Se empleó plata para cubrir la espada del rey Juan I (casetón 27). Finísimas láminas de oro se usaron para decorar los atributos reales: coronas, cinturones, cetros, espadas y rosarios. En diferentes partes de la decoración fueron detectados pigmentos como azurita, malaquita, bermellón y negro de humo. La composición del mortero de la estructura era a base de cal y dolomita molida.The present article describes a chemical and physical study of the colour, chemical composition and mineral phases of the decorative materials in the Seville City Hall Chapter House ceiling. The findings showed that the inner most layer of material, calcite, was covered with white lead, in turn concealed under a layer of gilded bole. The ceiling underwent re-gilding, also over bole, due in all likelihood to wear on the original gold leaf. In the nineteenth century, the entire ceiling with the exception of the inscriptions was whitewashed with calcite and white lead. Silver was employed on King John I’s sword (coffer 27). Gold leaf was used to adorn the royal attributes: crowns, belts, sceptres, swords and rosary beads. The high reliefs were likewise gilded. The pigments identified on the ceiling adornments included azurite, malachite, vermilion and gas black. A lime and ground dolomite mortar was used throughout
Study of the dehydroxylation-rehydroxylation of pyrophyllite
Pyrophyllite is a raw material of significant interest due to its large number of applications. Most of these applications require a thermal transformation of pyrophyllite; this thermal transformation implies the release of structural OH groups and the formation of new phases. In this paper, we report on the dehydroxylation of pyrophyllite and the reversibility of the process. A value of 224±16 kJ/mol for the dehydroxylation of pyrophyllite was obtained. In addition, it was observed that the partially or totally dehydroxylated pyrophyllite suffered a partial reversible rehydroxylation when cooled to room temperature. This rehydroxylation was substantiated by thermogravimetric measurements, while infrared spectroscopic studies showed that, during the rehydroxylation, the intensity of the OH band at 3675 cm -1 increased as two new bands at 3690 and 3702 cm-1 appeared. This rehydroxylation process was heavily influenced by the particle size of the pyrophyllite. Thus, smaller particles (<1 μm) showed a larger rehydroxylation percentage (about 12%), while the larger ones (20-40 μm) showed a smaller percentage (about 1.6%). The extent of rehydroxylation also depended on the dehydroxylation temperature and reached a maximum value at 750°C.Ministerio de Economía y Competitividad 2008-06619/MATJunta de Andalucía TEP-0300
Non-invasive analytical techniques applied to characterize the components of ancient golden medallions
Propiedades de la cal en pasta obtenida a partir del tratamiento de fosfoyesos de la industria de fertilizantes
El proceso industrial de
fabricación de ácido fosfórico tiene como materia prima principal la roca
fosf
orita, compue
sta mayoritariamente por apatito
(Ca
5
(PO
4
)
3
OH); produciéndose el ácido
fosfórico por un lado y por otro un subproducto formado principalmente por sulfato hidratado
de calcio, denominado fosfoyeso.
La producción de ácido fosfórico en Huelva (SO España) ha sido objeto de controversia por la
formación de balsas de este subproducto, sin suficiente control, en las marismas de la
desembocadura del río Tinto. Un grupo
de
investigadores liderados desde el Dpto. de Física de la
Materia Condensada de la Universidad de Sevilla ha desarrollado un procedimiento sencillo y
muy eficiente de obtención de portlandita, en forma de pasta de cal, como producto de la
reacción química de u
na disolución de fosfoyesos con una solución de sosa alcalina:
CaSO
4
·2H
2
O + 2NaOH
Ca(OH)
2
+ Na
2
SO
4
+ 2H
2
O
Como es previsible, la portlandita obtenida es susceptible de carbonatación, actuando como
sumidero para el secuestro mineral de CO
2
. Esta metodolog
ía tiene el potencial de reducir
simultáneamente dos problemas ambientales: la gestión de los residuos industriales peligrosos;
y las emisiones de gases de efecto invernadero.
Este trabajo presenta la caracterización química, mineralógica, morfología y granulométrica del
producto obtenido de cara su potencial utilización en aplicaciones relacionadas con el sector de
la construcción, considerando inicialmente sus posibilidades como conglomerante y
consolidant
Role of age and comorbidities in mortality of patients with infective endocarditis
[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.
[Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk.
[Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality.
[Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
Cuadernos de divulgación científica : encuentros con la ciencia 2
Recoge las ponencias impartidas por investigadores del cicCartuja a alumnos de Bachillerato en el marco de la X Semana de la Ciencia y la Tecnología: Una apuesta decidida por la divulgación / Miguel Ángel de la Rosa Acosta. Diez descubrimientos que cambiaron la visión del mundo / Manuel Lozano Leyva. El poder de la cisteína / Cecilia Gotor Martínez. ¡Las bacterias no son tan simples! Desde células individuales hasta organismos complejos / Victoria Merino-Puerto, Antonia Herrero y Enrique Flores Garcia. Aplicaciones tecnológicas de películas delgadas / Juan Pedro Espinós Manzorro. Ciencia y tecnología al servicio del arte / Adrián Durán Benito. El desafío de transportar medicamentos a células, tejidos y órganos : el potencial terapéutico del transporte selectivo de fármacos / Juan Manuel Benito Hernández. La Química Organometálica : qué es, para qué se utiliza y su contribución a la sociedad / Salvador ConejeroN
Prosthetic Valve Candida spp. Endocarditis: New Insights Into Long-term Prognosis—The ESCAPE Study
International audienceBackground: Prosthetic valve endocarditis caused by Candida spp. (PVE-C) is rare and devastating, with international guidelines based on expert recommendations supporting the combination of surgery and subsequent azole treatment.Methods: We retrospectively analyzed PVE-C cases collected in Spain and France between 2001 and 2015, with a focus on management and outcome.Results: Forty-six cases were followed up for a median of 9 months. Twenty-two patients (48%) had a history of endocarditis, 30 cases (65%) were nosocomial or healthcare related, and 9 (20%) patients were intravenous drug users. "Induction" therapy consisted mainly of liposomal amphotericin B (L-amB)-based (n = 21) or echinocandin-based therapy (n = 13). Overall, 19 patients (41%) were operated on. Patients <66 years old and without cardiac failure were more likely to undergo cardiac surgery (adjusted odds ratios [aORs], 6.80 [95% confidence interval [CI], 1.59-29.13] and 10.92 [1.15-104.06], respectively). Surgery was not associated with better survival rates at 6 months. Patients who received L-amB alone had a better 6-month survival rate than those who received an echinocandin alone (aOR, 13.52; 95% CI, 1.03-838.10). "Maintenance" fluconazole therapy, prescribed in 21 patients for a median duration of 13 months (range, 2-84 months), led to minor adverse effects.Conclusion: L-amB induction treatment improves survival in patients with PVE-C. Medical treatment followed by long-term maintenance fluconazole may be the best treatment option for frail patients
Role of age and comorbidities in mortality of patients with infective endocarditis.
The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups: A total of 3120 patients with IE (1327 There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in th