285 research outputs found

    Evolución de la planta de concentración de la mina de estaño "El cubito" Salamanca

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    [Resumen] Durante los últimos diez años la mina de estaño "El Cubito", en la provincia de Salamanca, ha mantenido una producción regular e importante dentro del contexto español, pese a constituir un criadero de los habitualmente clasificados como "marginales" por su escasa ley media. La utilización de los recursos técnicos disponibles, que ha conseguido el elevado grado de eficacia necesario para hacer rentable la explotación del yacimiento, ha estado basada en la experiencia como método y la simplificación de procesos como objetivos.[Abstract] For the last ten years the tin mine "El Cubito" , in the province of Salamanca, has kept a regular and important production, within the Spanish context, in spite of to belong to mineral deposits classified as "marginal" because of their short grade. The use of the available technical means, which has made possible the high degree of efficacy needed to make profitable the exploitation, has been based on the experience as method and on a simplification of processes as objetives

    Shear-induced microstructural transitions in aqueous systems containing an esterquat cationic surfactant

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    Se presenta un estudio basado en técnicas reológicas y de microscopía electrónica de barrido de bajas temperaturas (cryo-SEM) sobre los cambios de microestructura provocados por el flujo en cizalla de dispersiones acuosas de un tensioactivo catiónico tipo esterquat. Se comparan micrografías de cryo-SEM y las respuestas bajo cizalla oscilatoria de dispersiones sin y con cloruro de calcio. Esta última no presenta zona de comportamiento viscoelástico lineal, apuntando su respuesta no lineal a un fenómeno de estructuración inducida por cizalla. Ensayos transitorios de inicio al flujo, entre 0,1s-1 y 2000s-1, confirman que se producen aumentos de viscosidad más acusados con el tiempo de flujo a medida que aumenta la velocidad de cizalla. La técnica de cryo-SEM apoya que los resultados transitorios se deben a que un exceso de energía mecánica provoca transiciones de bicapas de tensioactivo a vesículas. Diferentes ensayos reológicos realizados en serie avalan la naturaleza irreversible, en la escala de tiempo de esta investigación, de las transiciones microestructurales inducidas por cizalla. Se demuestra que a pesar de la presencia de cloruro de calcio (0,1%), la aplicación de una velocidad de cizalla excesiva puede dar lugar a la aparición de respuestas viscoelásticas lineales significativas.This paper deals with a rheological and microstructural (cryo- SEM) characterization of shear-induced microstructure transitions in aqueous dispersions of an esterquat cationic surfactant. Cryo-SEM micrographs and oscillatory shear results of systems containing or not calcium chloride are compared. The addition of calcium chloride precluded the occurrence of significant viscoelastic properties and the estimation of the linear viscoelastic range. The non-linear oscillatory response pointed to the occurrence of incipient shear-induced build-up phenomena. Start-up flow tests between 0.1s-1 and 2000s-1 showed that the increase of viscosity with shear time was more marked as shear rate was increased. Cryo-SEM observations supported that build-up results in transient flow were due to an excess of mechanical energy, which resulted in transitions from surfactant bilayers to vesicles. Several series of rheological tests were carried out to demonstrate that shear-induced microstructure transitions were irreversible in the time scale of this investigation. Despite the addition of calcium chloride (0.1% wt), the shear-induced dispersion of vesicles may provoke the onset of significant linear viscoelasticity.Es presenta un estudi basat en tècniques reològiques i de microscòpia electrònica d’escombratge de baixes temperaturas (cryo-SEM) sobre els canvis de microestructura provocats pel flux en cisalla de dispersions aquoses d’un tensioactiu catiònic tipus esterquat. Es comparen micrografies de cryo-SEM i les respostes sota cisallament oscil•latòri de dispersions sense i amb clorur de calci. Aquesta darrera no presenta zona de comportament viscoelàstic lineal, apuntant la seva resposta no lineal a un fenomen d’estructuració induïda per cisallament. Assaigs transitoris d’inici al flux, entre 0,1s-1 y 2000s-1, confirmen que es produeixen augments de viscositat més acusats amb el temps de flux a mesura que augmenta la velocitat de cisallament. La técnica de cryo-SEM recolza que els resultats transitoris es deuen a que un excés d’energia mecànica provoca transicions de bicapes de tensioactiu a vesícules. Diferents assaigs reològics realitzats en sèrie avalen la naturalesa irreversible, a la escala de temps d’aquesta investigació, de les transicions microestructurals induïdes per cisallament. Es demostra que, tot i la presència de clorur de calci (0,1%), l’aplicació de una velocitat de cisallament excessiva pot donar lloc a l’aparició de respostes viscoelàstiques lineals significatives

    IAA : Información y actualidad astronómica (4)

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    Sumario : Investigación : Galaxias huéspedes de cuásares.-- El gigante gaseoso y su gran mancha roja.-- Ventana Abierta: Un futuro incierto.-- Charlas con… John Hutchings.-- Actualidad Científica: La edad de la galaxia.-- Sorpresas en el cinturón de Kuiper.-- Actividades IAA.-- Agenda.N

    Doxorubicin plus lurbinectedin in patients with advanced endometrial cancer: Results from an expanded phase i study

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    Objective: Second-line treatment of endometrial cancer is an unmet medical need. We conducted a phase I study evaluating lurbinectedin and doxorubicin intravenously every 3 weeks in patients with solid tumors. The aim of this study was to characterise the efficacy and safety of lurbinectedin and doxorubicin for patients with endometrial cancer. Methods: Thirty-four patients were treated: 15 patients in the escalation phase (doxorubicin 50 mg/m2 and lurbinectedin 3.0-5.0 mg) and 19 patients in the expansion cohort (doxorubicin 40 mg/m2 and lurbinectedin 2.0 mg/m2). All histological subtypes were eligible and patients had received one to two prior lines of chemotherapy for advanced disease. Antitumor activity was evaluated every two cycles according to the Response Evaluation Criteria in Solid Tumors version 1.1. Adverse events were graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4. Results: Median age (range) was 65 (51-78) years. Eastern Cooperative Oncology Group performance status was up to 1 in 97% of patients. In the escalation phase, 4 (26.7%) of 15 patients had confirmed response: two complete and two partial responses (95% CI 7.8% to 55.1%). Median duration of response was 19.5 months. Median progression-free survival was 7.3 (2.5 to 10.1) months. In the expansion cohort, confirmed partial response was reported in 8 (42.1%) of 19 patients (95% CI 20.3% to 66.5%). Median duration of response was 7.5 (6.4 to not reached) months, median progression-free survival was 7.7 (2.0 to 16.7) months and median overall survival was 14.2 (4.5 to not reached) months. Fatigue (26.3% of patients), and transient and reversible myelosuppression (neutropenia, 78.9%; febrile neutropenia, 21.1%; thrombocytopenia, 15.8%) were the main grade 3 and higher toxicities in the expanded cohort. Conclusions: In patients with recurrent advanced endometrial cancer treated with doxorubicin and lurbinectedin, response rates (42%) and duration of response (7.5 months) were favorable. Further evaluation of doxorubicin and lurbinectedin is warranted in this patient population

    Estudio de la estabilidad física, propiedades reológicas y microestructura de sistemas Aerosil 200/agua. Influencia de un tensioactivo no iónico

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    Se han estudiado las propiedades reológicas, la estabilidad física y la microestructura de suspensiones de una sílice hidrofílica (Aerosil 200) en agua con potencial aplicación como fase continua de emulsiones ecológicas. Además, se analizó la influencia de la adición de Amidet N, un tensioactivo no iónico derivado del aceite de Colza, en las propiedades viscoelásticas y la microestructura de las dispersiones. Se muestran diferentes comportamientos reológicos dependiendo de la concentración de Aerosil 200 en los sistemas binarios. Existe un aumento importante del carácter gel del 8% al 9% de Aerosil 200 mejorando la estabilidad física. Este cambio está relacionado con el grado de interacción de las partículas, como se muestra en la microscopia electrónica de barrido (Cryo-SEM). La adición de Amidet N a la suspensión provocó un incremento de los módulos viscosos y elásticos mostrándose una estructura más compacta. El sistema que contiene 6% de Aerosil 200 y 3% de Amidet N mostró adecuadas propiedades reológicas para su uso como fase continua de emulsiones que respetan el medio ambiente. Finalmente, cabe destacar el interés del estudio de este tipo de sistemas intermedios como punto de partida para el desarrollo de emulsiones.Aerosil 200/water dispersions and Aerosil 200/water/Amidet N were studied by means of rheological, microstructural and multiple light scattering techniques. These systems can find application as continuous phase in emulsions. Rheological tests such as flow curve and small amplitude oscillatory shear tests detected an abrupt change of behaviour related to microstructural interaction grade reflected through the Cryo-SEM micrographs. The most concentrated systems turned out to be more physically stable. An increase of viscoelastic properties was detected as a consequence of addition of Amilet N, which led to more compact microstructure. Finally, it is worth noting the interest of studying this type of intermediate systems as a starting point for the development of emulsions.Plan Propio de la Universidad de Sevilla Proyecto: 2017/00000962Ministerio de Economía y Competitividad (España) / FEDER, UE CTQ2015-70700-

    Methodology for development of ecological emulsions formulated with green solvents or essential oils

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    Las emulsiones ecológicas se formulan y preparan idealmente siguiendo los principios del desarrollo sostenible o la química verde. Estas emulsiones verdes poseen un gran número de aplicaciones, ya que por ejemplo son utilizadas en la industria alimentaria. La industria química está mostrando especial atención a la sustitución de los disolventes sintéticos por disolventes ecológicos en el desarrollo de emulsiones aceite-en-agua para usos agroquímicos, como pinturas, tintas de impresión, desengrasantes y como limpiadores. Los disolventes ecológicos se utilizan cada vez más como consecuencia de la prohibición de algunos disolventes orgánicos tradicionales y sintéticos. Por este motivo, los científicos e ingenieros responsables del desarrollo de productos están afrontando el desafío de formular emulsiones que contienen nuevos disolventes, tensioactivos o aditivos obtenidos a partir de fuentes renovables y con buenas propiedades ecológicas. En este capítulo se desarrolla una metodología para el desarrollo de emulsiones ecológicas con componentes obtenidos a partir de fuentes renovables, de nula toxicidad y biodegradables como una alternativa sostenible a aquellos productos que contienen disolventes orgánicos tradicionales.Green emulsions are formulated and ideally prepared under the principles of the so-called sustainable development or green chemistry and find a great variety of applications. These systems are increasingly used by the food industry insofar as there is an increasing tendency to reduce the number of synthetic additives and to increase the use of biomaterials and ingredients with functional properties. For similar reasons they are more and more used by the pharmaceutical and cosmetic industries. The chemical industry is also paying attention to the substitution of synthetic solvents by green solvents in water-based emulsions used as agrochemicals, paints, printing inks, fat removers and all-purpose cleaners. Green solvents are increasingly used since many synthetic solvents have been banned due to their carcinogenic or toxic properties and to their poor biodegradability. For this reason, scientists and engineers responsible for product development face the challenge to formulate emulsions containing new solvents, surfactants and additives obtained from renewable raw materials and exhibiting enhanced ecological properties.Plan Propio de la Universidad de Sevilla Proyecto: 2017/00000962Ministerio de Economía y Competitividad (España) / FEDER, UE CTQ2011-27371Ministerio de Economía y Competitividad (España) / FEDER, UE CTQ2015-7070

    Sleep apnoea increases biomarkers of immune evasion, lymphangiogenesis and tumour cell aggressiveness in high-risk patients and those with established lung cancer

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    Intermittent hypoxaemia and obstructive sleep apnoea (OSA) have been linked to lung cancer through as yet unidentified pathophysiological mechanisms. This study evaluates the effect of OSA on serum levels of biomarkers of immunosurveillance, lymphangiogenesis and intrinsic tumour cell aggressiveness in high-risk individuals screened for lung cancer and patients with established lung cancer. Serum samples from individuals participating in a lung cancer screening cohort (SAILS study) or with newly diagnosed lung cancer (SAIL study) were analysed. All patients underwent home sleep apnoea testing. Soluble levels of programmed cell death-1 (PD-1), programmed cell death ligand-1 (PDL1), cytotoxic T-lymphocyte antigen-4, midkine (MDK), paraspeckle component-1 (PSPC1), transforming growth factor-β1 (TGF-β1), SMAD3, matrix metalloproteinase-2 and co-stimulus receptor of the tumour necrosis factor family of receptors (CD137) were determined by ELISA. The presence of moderate-to-severe OSA was associated with increased levels of PSPC1, MDK, PD-L1 and PD-1 in screened individuals, and with higher values of PSPC1, TGF-β1, PD-L1 and PD-1 in patients with established lung cancer. The findings correlated with nocturnal intermittent hypoxaemia indices. Moderate-to-severe OSA is associated with increased expression of serum biomarkers of immune evasion, lymphangiogenesis and tumour cell aggressiveness in high-risk individuals screened for lung cancer and those with established diseaseThis study was supported by grants from Instituto de Salud Carlos III (ISCIII) PI19/01612, PI22/01262 and P2022/BMD-7224 to F. García-Río, CP18/00028, PI19-01363 and PI22/01257 to C. Cubillos-Zapata, PI20/01416 to L.M. Seijo and G. Peces-Barba; a grant from the Spanish Thoracic Society (SEPAR) to L.M. Seijo; and cofunded by the European Union, Ayudas Luis Alvarez 2021 FIBHULP. Funding information for this article has been deposited with the Crossref Funder Registr

    The young open cluster NGC 7067 using Strömgren photometry

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    © 2016 The Authors. NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the MilkyWay spiral arms. Strömgren photometry taken with theWide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the observed stars and hence to derive the cluster's physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4 ±0.4 kpc, with an age below log10(t(yr)) = 7.3 and a present mass of 1260 ± 160 M⊙. The morphology of the data reveals that the centre of the cluster is at (α, δ) = (21: 24: 13.69, +48: 00: 39.2) J2000, with a radius of 6.1 arcmin. Strömgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature

    The young open cluster NGC 7067 using Stromgren photometry

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    © The Authors 2016. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. M. Monguio et al, ' The young open cluster NGC 7067 using Stromgren photometry ', MNRAS Vol 466(3): 3636-3647 (2017), first published online 17 December 2016, the version of record is available online via doi: 10.1093/mnras/stw3302NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the Milky Way spiral arms. Stromgren photometry taken with the Wide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the bserved stars and hence to derive cluster’s physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4±0.4 kpc, with an age below log10(t(yr))=7.3 and a present Mass of 1260±160M⊙. The morphology of the data reveals that the centre of the cluster is at (α,δ)=(21: 24: 13.69,+48: 00: 39.2) J2000, with a radius of 6.′1. Stromgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature.Peer reviewedFinal Published versio

    Effect of Rosmarinus Officinalis Essential Oil On Anxiety, Depression, And Sleep Quality

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    Introduction: The objective of this investigation was to evaluate the effect of Rosmarinus officinalis essential oil on anxiety, depression, and sleep quality. Methods: The essential oils were extracted by hydro-distillation using a modified Clevenger-type apparatus and the chemical composition was performed by Gas chromatography with flame ionization detection (GC-FID) and Gas chromatography mass spectrometry (GC–MS). Furthermore, a quasi-experimental study was conducted, where 81 participants were divided into two groups, comprising a waiting list control group and an experimental group treated with essential oils. Anxiety and depression indexes were evaluated using the Zung Self-Rating Anxiety Scale (SAS) and the Zung Self-Rating Depression Scale (SDS), and sleep quality was measured with the Pittsburgh Sleep Quality Inventory (PSQI). Results: Chemical analysis showed that 1,8 cineole (37.6%), α-pinene (19.9%), and linalool (15.8%) were the main components. Anxiety, depression, and sleep quality scores showed a decrease in the post-test study phase compared to the pre-test in the experimental group (p<0.05). A large size effect was found in the case of anxiety (d = 1.491; g= 1.490) with 1-β=0.996, while medium size effects were observed for depression (d = 0.581; g= 0.582) with 1-β=0.585; and sleep quality (d = 0.586; g = 0.588) with 1-β=0.638. Conclusion: Essential oils extracted from Rosmarinus officinalis are more effective in calming anxiety and show moderate changes in depression and sleep quality
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