1,149 research outputs found

    Propiedades magnéticas de los sedimentos de tipo estuarino. El caso de las Rías Baixas.

    Get PDF
    Este trabajo establece la utilidad de la susceptibilidad magnética como indicador de la influencia marina y evolución diagenética en sedimentos costeros de las Rías Baixas. Para ello se investigó la variabilidad geográfica de la susceptibilidad en 200 muestras de sedimentos marinos superficiales en las Rías de Vigo y Pontevedra. Su variabilidad vertical se estudió en 80 muestras de tres testigos de entre 60 y 90 cm de longitud extraídos en la Ría de Pontevedra. La susceptibilidad de las muestras superficiales aumenta progresivamente hacia mar abierto, y a medida que nos alejamos de las zonas de mayor influencia continental, estando relacionada con la textura y composición del sedimento, y por tanto, con su procedencia. Los testigos, más homogéneos litológicamente, mostraron una disminución muy importante de la susceptibilidad con la profundidad, estando ésta asociada a la evolución diagenética del sedimento. Para estudiar mejor estos procesos, se determinó la composición elemental y mineralógica, y además se midieron otras propiedades magnéticas de muestras representativas. Estos resultados se analizaron conjuntamente con los datos sedimentológicos disponibles, lo que permitió establecer que la variabilidad de 151 D. Rey et al. Propiedades magnéticas de los sedimentos de tipo estuarino... la susceptibilidad dependía de tres factores principales: (a) procedencia y origen de los sedimentos, (b) régimen hidrodinámico de la zona y (c) presencia de partículas contaminantes discretas de origen antropogénico. También puede concluirse que la evolución de las fases magnetomineralógicas durante la diagénesis temprana está controlada por el contenido en materia orgánica, lo que a su vez determina el potencial de oxidación-reducción.Meassurement of magnetic susceptibility has allowed the assesment of the marine influence and diagenetic evolution of coastal sediments from the Rías Baixas. This is based on geographically and vertically distributed data. The lowfield susceptibility () of over 200 samples of surficial seabed sediments of the Rias of Vigo and Pontevedra showed a significant increase towards the open sea and away from continental influenced areas. Vertical variability of the susceptibility was evaluated in 80 samples obtained from three 60 to 90 cm long gravity corers in the Ria de Pontevedra. These samples showed a very strong decrease in susceptibility with depth. The surficial susceptibility values correlated well with the textural characteristics of the sediments, suggesting a link between sediment provenance and origin of the magnetic signal. To further evaluate these relationships, the available sedimentological data were completed with a number of elemental and mineralogical analysis. In addition some basic magnetic parameters were obtained for selected specimens. The combined analysis of these data showed that the spatial variability of the susceptibility observed in the different granulometric fractions can be spatially related to: (a) sediment provenance and origin, (b) hydrodynamic regime established between the Rias and the adjacent shelf, (c) antropogenic solid particulate pollution. It can also be concluded that the evolution of the magnetomineralogical phases during the early stages of burial and diagenesis is controlled by the organic matter content which in turn controls the redox potential

    Effect of Yb concentration on the resistivity and lifetime of CdTe:Ge:Yb codoped crystals

    Get PDF
    The resistivity and electron lifetime of CdTe:Ge:Yb crystals are reported, demonstrating that the effect of Yb concentration is crucial for accurate electrical compensation. It is also demonstrated that the codoping of CdTe with Ge as deep donor and with Yb as rare-earth element could be a promising way to obtain semiinsulating CdTe crystals with good transport properties. High resistivity 5 10 9 cm and lifetime 9 s were obtained, thus confirming the beneficial effect of rare-earth dopingThis work has been partly supported by the projects CAM SENSORCDT S-0505/MAT/0209, CAM FOTOFLEX S-0505/ENE-123, and EU FP6 PHOLOGIC 017158. E.S. also acknowledges the Spanish MEC for the fellowship FPU 2003-1388.Peer reviewe

    Targets, mechanisms and cytotoxicity of half-sandwich Ir(III) complexes are modulated by structural modifications on the benzazole ancillary ligand

    Get PDF
    Cancers are driven by multiple genetic mutations but evolve to evade treatments targeting specific mutations. Nonetheless, cancers cannot evade a treatment that targets mitochondria, which are essential for tumor progression. Iridium complexes have shown anticancer properties, but they lack specificity for their intracellular targets, leading to undesirable side effects. Herein we present a systematic study on structure-activity relationships of eight arylbenzazole-based Iridium(III) complexes of type [IrCl(Cp*)], that have revealed the role of each atom of the ancillary ligand in the physical chemistry properties, cytotoxicity and mechanism of biological action. Neutral complexes, especially those bearing phenylbenzimidazole (HL1 and HL2), restrict the binding to DNA and albumin. One of them, complex 1[C,NH-Cl], is the most selective one, does not bind DNA, targets exclusively the mitochondria, disturbs the mitochondria membrane permeability inducing proton leak and increases ROS levels, triggering the molecular machinery of regulated cell death. In mice with orthotopic lung tumors, the administration of complex 1[C,NH-Cl] reduced the tumor burden. Cancers are more vulnerable than normal tissues to a treatment that harnesses mitochondrial dysfunction. Thus, complex 1[C,NH-Cl] characterization opens the way to the development of new compounds to exploit this vulnerability

    Interface Depinning in the Absence of External Driving Force

    Full text link
    We study the pinning-depinning phase transition of interfaces in the quenched Kardar-Parisi-Zhang model as the external driving force FF goes towards zero. For a fixed value of the driving force we induce depinning by increasing the nonlinear term coefficient λ\lambda, which is related to lateral growth, up to a critical threshold. We focus on the case in which there is no external force applied (F=0) and find that, contrary to a simple scaling prediction, there is a finite value of λ\lambda that makes the interface to become depinned. The critical exponents at the transition are consistent with directed percolation depinning. Our results are relevant for paper wetting experiments, in which an interface gets moving with no external driving force.Comment: 4 pages, 3 figures included, uses epsf. Submitted to PR

    Age-dependent impact of two exercise training regimens on genomic and metabolic remodeling in skeletal muscle and liver of male mice

    Get PDF
    Skeletal muscle adapts to different exercise training modalities with age; however, the impact of both variables at the systemic and tissue levels is not fully understood. Here, adult and old C57BL/6 male mice were assigned to one of three groups: sedentary, daily high-intensity intermittent training (HIIT), or moderate intensity continuous training (MICT) for 4 weeks, compatible with the older group’s exercise capacity. Improvements in body composition, fasting blood glucose, and muscle strength were mostly observed in the MICT old group, while effects of HIIT training in adult and old animals was less clear. Skeletal muscle exhibited structural and functional adaptations to exercise training, as revealed by electron microscopy, OXPHOS assays, respirometry, and muscle protein biomarkers. Transcriptomics analysis of gastrocnemius muscle combined with liver and serum metabolomics unveiled an age-dependent metabolic remodeling in response to exercise training. These results support a tailored exercise prescription approach aimed at improving health and ameliorating age-associated loss of muscle strength and function in the elderly.This work was supported by funding from the Intramural Research Program of the National Institute on Aging/NIH. Work in JMV laboratory was supported by the Spanish Ministerio de Economía y Competitividad (MINECO) grant BFU2015-64630-R, Ministerio de Ciencia, Innovación y Universidades (MICIU) grant RTI2018-100695-B-I00, Spanish Junta de Andalucía grants P18-RT-4264, 1263735-R and BIO-276, the FEDER Funding Program from the European Union, and Universidad de Córdoba. MCR was supported by a FPU fellowship from the Spanish Ministerio de Educación, Cultura y Deporte (reference FPU14/06308). SRL held a FPI predoctoral contract funded by MINECO (reference BES-2016-078229).Peer reviewe

    Functional upgrading in China’s export processing sector

    Get PDF
    Functional upgrading occurs when a firm acquires more sophisticated functions within an existing value chain. In this paper, we analyze if there is evidence of this type of upgrading in China’s export processing regime by investigating dynamics in the relative prevalence of Import & Assembly (IA) versus Pure Assembly (PA) processing trade over the period 2000-2013. Firms in both regimes provide similar manufacturing services to foreign companies, but IA firms also conduct the sophisticated tasks of quality control, searching, financing and storing imported materials. Consistent with a trend of functional upgrading, we show that the share of IA trade in total processing trade has increased rapidly during the period 2000-2006, both overall and within product categories. Furthermore, we find that this trend has gone hand in hand with improvements in a sector’s labor productivity and unit values. Against expectations, we find that this process has slowed down notably during the period 2006-2013.status: publishe

    Tamizaje químico y determinar la actividad amebicida, antioxidante y tóxica de los extractos metanólicos de <i>Jatropha dioica</i> y <i>Eucalyptus camaldulensis</i>

    Get PDF
    La Organización Mundial de la Salud ha estimado que aproximadamente el 80% de los habitantes a nivel mundial han utilizado la medicina tradicional para el cuidado de su salud. Entre las cuales se encuentran Jatropha dioica y Eucalyptus camaldulensis. Objetivo: realizar el tamizaje químico de Jatropha dioica y Eucalyptus camaldulensis, y determinar la actividad amebicida, antioxidante y tóxica de los extractos metanólicos de J. dioica y E. camaldulensis. Métodos: Se colectó el material vegetal de ambas especies, se obtuvieron los extractos y se realizó: a) tamizaje química, b) determinación de la actividad antioxidante, c) bioensayo de letalidad en Artemia salina y d) determinación de la actividad amebicida de los extractos metanólicos sobre Entamoeba histolytica. Resultados: Se determinaron los compuestos químicos presentes en los extractos de E. camaldulensis y J. dioica, los extractos de E. camaldulensis presentan mayor actividad antioxidante. El extracto etanólico de hoja de E. camaldulensis presenta menor toxicidad para A. salina, y el extracto metanólico de tallo de ambas especies presentaron el mayor potencial amebicida. Conclusiones: Los extractos con actividad amebicida podrían ser empleados en futuros trabajos de investigación encaminados a inhibir tanto el crecimiento como el enquistamiento de Entamoeba histolytica y de otros parásitos patógenos al humano.Universidad Nacional de La Plat

    Tamizaje químico y determinar la actividad amebicida, antioxidante y tóxica de los extractos metanólicos de <i>Jatropha dioica</i> y <i>Eucalyptus camaldulensis</i>

    Get PDF
    La Organización Mundial de la Salud ha estimado que aproximadamente el 80% de los habitantes a nivel mundial han utilizado la medicina tradicional para el cuidado de su salud. Entre las cuales se encuentran Jatropha dioica y Eucalyptus camaldulensis. Objetivo: realizar el tamizaje químico de Jatropha dioica y Eucalyptus camaldulensis, y determinar la actividad amebicida, antioxidante y tóxica de los extractos metanólicos de J. dioica y E. camaldulensis. Métodos: Se colectó el material vegetal de ambas especies, se obtuvieron los extractos y se realizó: a) tamizaje química, b) determinación de la actividad antioxidante, c) bioensayo de letalidad en Artemia salina y d) determinación de la actividad amebicida de los extractos metanólicos sobre Entamoeba histolytica. Resultados: Se determinaron los compuestos químicos presentes en los extractos de E. camaldulensis y J. dioica, los extractos de E. camaldulensis presentan mayor actividad antioxidante. El extracto etanólico de hoja de E. camaldulensis presenta menor toxicidad para A. salina, y el extracto metanólico de tallo de ambas especies presentaron el mayor potencial amebicida. Conclusiones: Los extractos con actividad amebicida podrían ser empleados en futuros trabajos de investigación encaminados a inhibir tanto el crecimiento como el enquistamiento de Entamoeba histolytica y de otros parásitos patógenos al humano.Universidad Nacional de La Plat
    corecore