29 research outputs found
Las mineralizaciones de Sn-Ti del borde occidental de la Cuenca de Ciudad Rodrigo
[Resumen] El borde Occidental de la Cuenca Terciaria de Ciudad Rodrigo presenta una serie de mineralizaciones de Sn y Ti, que han sido objeto de laboreo en varias ocasiones durante el presente siglo existiendo en la actualidad dos explotaciones de cierta importancia; una en Puebla de Azaba (Salamanca) y otra en Nave de Haver (Portugal). Los materiales detríticos en los que se encuentran la casiterita y la ilmenita proceden de la denudación del batolito de Guarda, que presenta facies leucograníticas con contenidos de estaño superiores a 500 ppm, y del desmantelamiento de su cortejo filoniano. Estas formaciones con contenidos de Sn muy irregulares, pero con valores generalmente inferiores a 200 ppm, son considerados como dep6sitos Deluviales. Las minas activas benefician fundamentalmente los aluviones recientes, que alcanzan contenidos de hasta 800 ppm de estaño[Abstract] Western borderland of the Ciudad Rodrigo Tertiary Basin bears a suite of Sn-Ti deposits that were mined for several times in this century. Nowadays, two relatively important mines occur in that zone: Puebla de Azaba (Salamanca) and Nave de Haver (Portugal) . -Detrital sediments with casiterite and ilmenite como from denudation of Guarda batholith, which present leuco granite facies with Sn contents up to 500 ppm. The detrital formatión, with variable Sn contents, generally less than 200 ppm, is considered as a "Deluvial" facies. Active mining focusses on recent alluvials whose Sn contents reach up 5OO ppm
Yacimientos de estaño del Oeste de España
[Resumen] En este trabajo se realiza una clasificación de los. yacimientos de estaño del oeste español basada, fundamentalmente, en consideraciones económicas. Tras una introducción explicativa de los objetivos y metodología empleados, así como una breve exposición del significado de las explotaciones de estaño españolas en el contexto mundial, se describen y clasifican los indicios y yacimientos más importantes, aportándose además un listado de la bibliografía específica más destacable[Abstract] This work presents a classification of the tin deposits in the westof Spain, based, mainly, on economic reasons. After an explaining introduction of the objetives and the method used, and a short exposition of the importance of spanish tin exploitations in the world context, the most important mines and occurrences are described and classified; in addition a list of the most relevant specific bibliography is given
Tungsten deposits in the west of Spain
[Resumen] En este trabajo se realiza una clasificación de los yacimientos de volframio del oeste español basada, fundamentalmente, en consideraciones económicas. Tras una introducción en la que se comenta la reciente historia del volframio, así como una breve exposición del significado de las explotaciones de volframioespañolas en el contexto mundial, se describen y clasifican los indicios y yacimientos más importantes, aportándose también un listado de la bibliografía específica más destacable.[Abstract] This work presents a classification of the tungsten deposits en the west of Spain, based, mainly, on economic reasons. Mter an explaining introduction of the recent history of the tungsten, and a short exposition of the importance of spanish exploitations in the world context, the most important mines and occurrences are described and c1assified; in addition a list of the most relevant specific bibliography is given
Caracteres geoquímicos y mineralógicos del yacimiento de Sn y Au de Montejo (Salamanca)
[Resumen] El yacimiento situado al S. E. de la Provincia de Salamanca está constituido por una serie de filones de cuarzo brechificado de dirección E-W, subverticales y encajados en materiales pertenecientes al Complejo Esquistograuváquico (Formación Monterrubio, dominando en esta zona esquistos, grauvacas y microconglomerados). Fue explotado durante los años 40 y 50 para Sn y esporádicamente para Au. Se han estudiado al microscopio 80 preparaciones pulidas y transparentes seleccionadas en cuatro sondeos de 250 metros, calicatas y antiguas escombreras, con el fin de caracterizar paragénesis, sucesión de la mineralización y alteraciones hidrotermales relacionadas. También se ha realizado un muestréo en las zonas mineralizadas y con alteración hidrotermal para su estudio geoquímico. Se han analizado: Au, As, Sb, Bi, Cu, Pb, Zn, Sn, Rb, Sr y Ba en 40 muestras. Las relaciones intereleme~ntales más evidentes son: Au-Sn-Bi y Cu-Sb. Por otro lado, se correlacionan los resultados geoquímicos con los diversos tipos de alteraciones hidrotermales.[Abstract] This tin-gold deposit is located in the SE Salamanca province. Mineralization is associated with several quartz-veins and breccias in metamorphic terrains of Precambrian-Cambrian ages (<<Complejo Esquistograuváquico»). Were studied microscopically 80 samples of four drillings (250 m deep) and other surface sampIes. It is presented mineral paragenesis and wall-rocks alterations relationed with mineralization. The geochemical stady include determinations of Au, As, Sb, Bi, Cu, Pb, Zn, Sn, Rb, Sr and Ba. A factor analysis on the geochemical data stablished the fo11owing associations: Au-Sn-Bi and Cu-Sb
Spread of a SARS-CoV-2 variant through Europe in the summer of 2020.
Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3–5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes. © 2021, The Author(s), under exclusive licence to Springer Nature Limited
Evolution of the use of corticosteroids for the treatment of hospitalised COVID-19 patients in Spain between March and November 2020: SEMI-COVID national registry
Objectives: Since the results of the RECOVERY trial, WHO recommendations about the use of corticosteroids (CTs) in COVID-19 have changed. The aim of the study is to analyse the evolutive use of CTs in Spain during the pandemic to assess the potential influence of new recommendations. Material and methods: A retrospective, descriptive, and observational study was conducted on adults hospitalised due to COVID-19 in Spain who were included in the SEMI-COVID- 19 Registry from March to November 2020. Results: CTs were used in 6053 (36.21%) of the included patients. The patients were older (mean (SD)) (69.6 (14.6) vs. 66.0 (16.8) years; p < 0.001), with hypertension (57.0% vs. 47.7%; p < 0.001), obesity (26.4% vs. 19.3%; p < 0.0001), and multimorbidity prevalence (20.6% vs. 16.1%; p < 0.001). These patients had higher values (mean (95% CI)) of C-reactive protein (CRP) (86 (32.7-160) vs. 49.3 (16-109) mg/dL; p < 0.001), ferritin (791 (393-1534) vs. 470 (236- 996) µg/dL; p < 0.001), D dimer (750 (430-1400) vs. 617 (345-1180) µg/dL; p < 0.001), and lower Sp02/Fi02 (266 (91.1) vs. 301 (101); p < 0.001). Since June 2020, there was an increment in the use of CTs (March vs. September; p < 0.001). Overall, 20% did not receive steroids, and 40% received less than 200 mg accumulated prednisone equivalent dose (APED). Severe patients are treated with higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%. Conclusions: Patients with greater comorbidity, severity, and inflammatory markers were those treated with CTs. In severe patients, there is a trend towards the use of higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%
The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients
Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation
Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study
Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life
Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU
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Génesis de una mineralización asociada a una cúpula granítica: el yacimiento de estaño de Golpejas, (Salamanca)
[Resumen] El yacimiento estannífero de Golpejas está constituído por varias láminas de un microgranito albítico que da lugar a estructuras más o menos circulares y atraviesa materiales del complejo esquisto -grauváquico y de las series suprayacentes ordovícicas y silúricas situadas 20 k. al oeste de Salamanca. Los minerales que constituyen el yacimiento --casiterita y columbo-tantalita-- aparecen dentro de los granitos, unas veces disemina dos, caso más frecuente, otras en filones de cuarzo que contienen anbligonita y sulfuros de Cu, Sn, Zn, Ag y Bi. Los leucogranitos albíticos se originaron en la etapa final de cristal ización de un magma muy diferenciado que hizo intrusión en niveles muy elevados de la corteza. Su formación sería una consecuencia de la probable existencia en profundidad de una cúpula granítica que se emplazó durante la segunda fase de deformación hercínica.[Abstract] The Golpejas tin deposit consists of several sheets of albite microgranites, more or less circular in shape, that intersect rock materials of the schist-graywacke comp1ex and the over1ying Ordovician and Silurian metasediments. Most frequent1y, the minerals making up the deposit –cassiterite and columbite-tantal ite-- are disseminated in the granite, but ocassionally they also occur in intragranitc quartz veins containing ambl igonite and Cu, Sn, Zn, Ag and Bil sulphides. The albite leucogranite were generated during the final crystalization stage of a highly differentiated magma. They were intruded at a relatively shallow level following the emplacement in depth of a granitic cupola during the second Hercynian, tectonic phas