Dispersion of gamma-Alumina Nano-Sized Spherical Particles in a Calamitic Liquid Crystal. Study and Optimization of the Confinement Effects

We report an experimental study on confined systems formed by butyloxybenzylidene octylaniline liquid crystal (4O.8) + gamma-alumina nanoparticles. The effects of the confinement in the thermal and dielectric properties of the liquid crystal under different densities of nanoparticles is analyzed by means of high resolution Modulated Differential Scanning Calorimetry (MDSC) and broadband dielectric spectroscopy. First, a drastic depression of the N-I and SmA-N transition temperatures is observed with confinement, the more concentration of nanoparticles the deeper this depression is, driving the nematic range closer to the room temperature. An interesting experimental law is found for both transition temperatures. Second, the change in shape of the heat capacity peaks is quantified by means of the full width half maximum (FWHM). Third, the confinement does not noticeably affect the molecular dynamics. Finally, the combination of nanoparticles and the external applied electric field tends to favor the alignment of the molecules in metallic cells. All these results indicate that the confinement of liquid crystals by means of gamma-alumina nanoparticles could be optimum for liquid crystal-based electrooptic devices.

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Nivel educativo: Grado. Duración (en horas): De 31 a 40 horas

Sphingomyelinase D/Ceramide 1-Phosphate in Cell Survival and Inflammation

Sphingolipids are major constituents of biological membranes of eukaryotic cells. Many studies have shown that sphingomyelin (SM) is a major phospholipid in cell bilayers and is mainly localized to the plasma membrane of cells, where it serves both as a building block for cell architecture and as a precursor of bioactive sphingolipids. In particular, upregulation of (C-type) sphingomyelinases will produce ceramide, which regulates many physiological functions including apoptosis, senescence, or cell differentiation. Interestingly, the venom of some arthropodes including spiders of the genus Loxosceles, or the toxins of some bacteria such as Corynebacterium tuberculosis, or Vibrio damsela possess high levels of D-type sphingomyelinase (SMase D). This enzyme catalyzes the hydrolysis of SM to yield ceramide 1-phosphate (C1P), which promotes cell growth and survival and is a potent pro-inflammatory agent in different cell types. In particular, C1P stimulates cytosolic phospholipase A2 leading to arachidonic acid release and the subsequent formation of eicosanoids, actions that are all associated to the promotion of inflammation. In addition, C1P potently stimulates macrophage migration, which has also been associated to inflammatory responses. Interestingly, this action required the interaction of C1P with a specific plasma membrane receptor, whereas accumulation of intracellular C1P failed to stimulate chemotaxis. The C1P receptor is coupled to Gi proteins and activates of the PI3K/Akt and MEK/ERK1-2 pathways upon ligation with C1P. The proposed review will address novel aspects on the control of inflammatory responses by C1P and will highlight the molecular mechanisms whereby C1P exerts these actions.

Puesta en marcha del nuevo cromatógrafo AC Reformulyzer M4 para la determinación de familias de hidrocarburos, oxigenados y benceno en gasolinas y naftas en refinería

El objetivo de este estudio es la puesta en marcha del cromatógrafo Analytical Control -Reformulyzer M4, destinado a la determinación de la composición de hidrocarburos, oxigenados y benceno en gasolinas y naftas de la refinería. Además, se trata de comprender la importancia del equipo en el marco industrial.

Sedimentazioaren gaineko kontrolak Murgiako diapiroaren ipar-mendebaldean

Eusko Kantauriar Arroko Albiar-Cenomaniar mugaren inguruan trnsgresio orkorra gertatu zen subsidentzia tektonikoaren desazelerazio eta diapirismoaren sortze efektuarekin batera. Honen ondorioz, kostaldeko ingurune siliziklastikoek oso erretrogradazio arina erakusten dute, hedapen handiko karbonatozko arrapal itsastar zabalen garapenerako eremua utziz. Analisi estratigrafikoaren bidez, Murgiako diapiroaren iparmendebaldeko Albiar-Cenomaniar trasizioko materialak aztertzen dira, aldaketa sedimentologiko arin honetarako ezaugarriak eta kontrolak ezagutzeko.