Engineering the microstructure and magnetism of La2_2CoMnO6_6 thin films by tailoring oxygen stoichiometry

We report on the magnetic and structural properties of ferromagnetic-insulating La$_2$CoMnO$_6$ thin films grown on top of (001) STO substrates by means of RF sputtering technique. Careful structural analysis, by using synchrotron X-ray diffraction, allows identifying two different crystallographic orientations that are closely related to oxygen stoichiometry and to the features (coercive fields and remanence) of the hysteresis loops. Both Curie temperature and magnetic hysteresis turn out to be dependent on the oxygen stoichiometry. In situ annealing conditions allow tailoring the oxygen content of the films, therefore controlling their microstructure and magnetic properties

Electronic nature of the enhanced conductivity in YSZ-STO multilayers deposited by PLD

10 páginas, 8 figuras.-- et al.The search for new strategies to enhance the oxide ionic conductivity in oxide materials is a very active field of research. These materials are needed for application in a new generation of more efficient and durable solid state electrochemical devices such as reduced-temperature Solid Oxide Fuel Cells (SOFC's). Recently published results have claimed that sputtered yttria stabilised zirconia (YSZ)/SrTiO3 (STO) heterostructures show enhanced oxygen ion conductivity, by about eight orders of magnitude, with respect to that expected for YSZ and STO bulk values. The YSZ/STO heterostructures obtained in this work from Pulsed Laser Deposited (PLD) films, also show enhanced conductivity of a similar order. However, the fact that our structures show different relative orientations indicates that the conductivity enhancement may not be associated to a particular crystallographic arrangement at the interface. The combined characterisation of the conductivity dependence on oxygen partial pressure and direct oxygen diffusion by means of tracer experiments clearly demonstrate that the enhancement observed is related to the electronic rather than ionic conductivity.The authors also acknowledge the financial support of Spanish Government through projects: MAT2008-04931 and Consolider-Ingenio 2010-CSD2008-023. Two of the authors (A.C. and M.B.) acknowledge the support of their postdoctoral fellowships from the Spanish Ministry of Science and Innovation. DWM acknowledges the support of the Royal Academy of Engineering.Peer reviewe

Elongase Reactions as Control Points in Long-Chain Polyunsaturated Fatty Acid Synthesis

Extent: 9p.Background: Δ6-Desaturase (Fads2) is widely regarded as rate-limiting in the conversion of dietary α-linolenic acid (18:3n-3; ALA) to the long-chain omega-3 polyunsaturated fatty acid docosahexaenoic acid (22:6n-3; DHA). However, increasing dietary ALA or the direct Fads2 product, stearidonic acid (18:4n-3; SDA), increases tissue levels of eicosapentaenoic acid (20:5n-3; EPA) and docosapentaenoic acid (22:5n-3; DPA), but not DHA. These observations suggest that one or more control points must exist beyond ALA metabolism by Fads2. One possible control point is a second reaction involving Fads2 itself, since this enzyme catalyses desaturation of 24:5n-3 to 24:6n-3, as well as ALA to SDA. However, metabolism of EPA and DPA both require elongation reactions. This study examined the activities of two elongase enzymes as well as the second reaction of Fads2 in order to concentrate on the metabolism of EPA to DHA. Methodology/Principal Findings: The substrate selectivities, competitive substrate interactions and dose response curves of the rat elongases, Elovl2 and Elovl5 were determined after expression of the enzymes in yeast. The competitive substrate interactions for rat Fads2 were also examined. Rat Elovl2 was active with C20 and C22 polyunsaturated fatty acids and this single enzyme catalysed the sequential elongation reactions of EPA→DPA→24:5n-3. The second reaction DPA→24:5n-3 appeared to be saturated at substrate concentrations not saturating for the first reaction EPA→DPA. ALA dose-dependently inhibited Fads2 conversion of 24:5n-3 to 24:6n-3. Conclusions: The competition between ALA and 24:5n-3 for Fads2 may explain the decrease in DHA levels observed after certain intakes of dietary ALA have been exceeded. In addition, the apparent saturation of the second Elovl2 reaction, DPA→24:5n-3, provides further explanations for the accumulation of DPA when ALA, SDA or EPA is provided in the diet. This study suggests that Elovl2 will be critical in understanding if DHA synthesis can be increased by dietary means.Melissa K. Gregory, Robert A. Gibson, Rebecca J. Cook-Johnson, Leslie G. Cleland and Michael J. Jame

Control oficial dels productes vitivinícoles: aplicació del SICA en establiments del sector del vi; criteris de flexibilitat

Petits cellers; Requisits d’higiene; APPCC; Criteris flexibilitat; SICAPequeñas bodegas; Requisitos de higiene; APPCC; Criterios flexibilidad; SICASmall wineries; Hygiene requirements; HACCP; Criteria of flexibility; SICADurant el procés de treball de la comunitat de pràctica (CoP) s’ha establert un cronograma d’actuacions. Els objectius que s’han prioritzat són: a) Donar informació sobre la importància dels establiments relacionats amb el món del vi i el vi escumós a Catalunya i la distribució territorial que tenen. b) Donar informació sobre els perills que s’han detectat aquests darrers anys en vins i vins escumosos, que han estat motiu de notificacions d’alerta a la Unió Europea o d’alguna incidència a Catalunya. c) Posar a disposició dels inspectors un recull de la normativa que afecta el sector vitivinícola. d) Elaborar un protocol d’inspecció que proporcioni una eina eficaç i útil per efectuar el control oficial dels establiments que elaboren i/o envasen productes vitivinícoles. e) Elaborar material de suport per als inspectors que faciliti la interpretació de les preguntes del protocol que poden generar dubtes en relació amb les pràctiques enològiques i la informació alimentària. f) Realitzar consultes a Serveis Centrals en relació amb diversos punts de la normativa que presenten dubtes d’interpretació per obtenir criteris homogenis i poder incloure’ls en el material de suport per als inspectors. g) Elaborar documents que incloguin els requisits mínims que han de tenir els establiments que realitzen activitats relacionades amb productes vitivinícoles i els criteris de flexibilitat que es podrien aplicar en casos determinats. Aquest ha estat un treball que la CoP ha realitzat durant dos anys.Durante el proceso de trabajo de la comunidad de práctica (CoP) se ha establecido un cronograma de actuaciones. Los objetivos que se han priorizado son: a) Dar información sobre la importancia de los establecimientos relacionados con el mundo del vino y el vino espumoso en Cataluña y su distribución territorial. b) Dar información sobre los peligros que se han detectado estos últimos años en vinos y vinos espumosos, que han sido motivo de notificaciones de alerta en la Unión Europea o de alguna incidencia en Cataluña. c) Poner a disposición de los inspectores una recopilación de la normativa que afecta al sector vitivinícola. d) Elaborar un protocolo de inspección que proporcione una herramienta eficaz y útil para efectuar el control oficial de los establecimientos que elaboren y/o envasen productos vitivinícolas. e) Elaborar material de soporte para los inspectores que facilite la interpretación de las preguntas del protocolo que pueden generar dudas en relación con las prácticas enológicas y la información alimentaria. f) Realizar consultas a Servicios Centrales en relación con varios puntos de la normativa que presenten dudas de interpretación para obtener criterios homogéneos y poder incluirlos en el material de soporte para los inspectores. g) Elaborar documentos que incluyan los requisitos mínimos que deben tener los establecimientos que realizan actividades relacionadas con productos vitivinícolas y los criterios de flexibilidad que podrían aplicarse en casos determinados. Éste ha sido un trabajo que la CoP ha realizado durante dos años.During the work process of the community of practice (CoP) a schedule has been established of performances. The objectives that have been prioritized are: a) Give information about the importance of establishments related to the world of wine and wine sparkling wine in Catalonia and its territorial distribution. b) Provide information on the dangers that have been detected in recent years in wines and sparkling wines, which have been the reason for alert notifications in the European Union or an incident in Catalonia. c) Make a compilation of the regulations that affect the wine sector available to inspectors. d) Develop an inspection protocol that provides an effective and useful tool for carrying out official control of establishments that produce and/or package wine products. e) Prepare support material for inspectors that facilitates the interpretation of protocol questions that may raise doubts in relation to oenological practices and food information. f) Make inquiries to Central Services in relation to various points of the regulations that present doubts of interpretation in order to obtain homogeneous criteria and be able to include them in the support material for inspectors. g) Prepare documents that include the minimum requirements that must be met by establishments that carry out activities related to wine products and the flexibility criteria that could be applied in specific cases. This has been work that the CoP has done for two years

Evolution of He-induced cavities and related defects in silicon studied by direct scattering of channeled particles

The number of scattering centres measured using channeled particles passing through a cavity layer formed by He implantation in silicon is shown to depend on the probe energy. This unusual result is explained in terms of interaction of channeled particles with atoms of cavity walls and dislocation lines. The Rutherford backscattering analysis in channeling incidence (RBS-C) is then used to study the time evolution of cavity and dislocation populations during annealing. It is shown that cavities are actually bubbles in equilibrium with the silicon matrix. The time to reach this equilibrium is related to the gas desorption. For our experimental conditions (40 keV, 5 × 1016 cm−2 and 800 °C), this equilibration time is about 10 minutes. Strain and dislocation build-up occur under shorter time scales, during which bubbles are probably overpressurized. The pinning of bubbles at dislocations must be taken into account to explain the evolution of these extended defects over a longer period