53 research outputs found

    Antagonistas de la GnRH en los tratamientos de reproducción asistida

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    La presente tesis doctoral repasa la repercusión que los antagonistas de la GnRH ha tenido sobre la efectividad y seguridad de los tratamientos de reproducción asistida a través de los distintos artículos publicados por el autor. Las conclusiones a las que se llega son que: 1. El uso de los antagonistas de la GnRH aumenta de forma significativa las tasas de embarazo en los ciclos de inseminación artificial. 2. El aumento de las tasa de embarazo evidenciados en los ciclos de inseminación artificial con el uso de los antagonistas de la GnRH sólo se produce si los ciclos son multifoliculares y no en los monofoliculares. 3. Los agonistas de la GnRH pueden ser utilizados como inductores de la maduración final oocitaria en los ciclos en los que se usan los antagonistas de la GRH, sin que afecten la calidad embrionaria. 4. En los ciclos de donación de oocitos el único protocolo recomendable es aquel en el que se usa primero un antagonista de la GnRH y después un agonista de la GnRH ya que evita el riesgo de hiperestimulación en la donante. 5. Las pacientes con síndrome de ovarios poliquísticos se benefician de un protocolo secuencial de antagonistas/agonistas de la GnRH y criopreservación de embriones, a fin de evitar el síndrome de hiperestimulación ovárica y mantener las tasas de embarazo.This doctoral thesis reviews the impact that theuse of GnRH antagonists has had on the effectiveness and safety of assisted reproduction treatments through the various articles published by the author. The conclusions reached are: 1. The use of GnRH antagonists significantly increases pregnancy rates in intrauterine insemination cycles. 2. Increasing pregnancy rates evidenced in artificial insemination cycles only occurs ifthe cycle is multifollicular. 3. GnRH agonists can be used to induce final oocyte maturation in cycles in which antagonists are used without affecting embryo quality. 4. In oocyte donation cycles the only recommended protocol is the one in which it is used first a GnRH antagonist and then a GnRH agonist to trigger ovulation. 5. Patients with polycystic ovary syndrome benefit from a sequential protocol antagonist / GnRH agonists and cryopreservation of embryos to prevent ovarian hyperstimulation syndrome and maintain pregnancy rates

    Tunable plasmonic resonance of gallium nanoparticles by thermal oxidation at low temperatures

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    This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after the 12 month embargo period provided that all the terms of the licence are adhered toThe effect of the oxidation of gallium nanoparticles (Ga NPs) on their plasmonic properties is investigated. Discrete dipole approximation has been used to study the wavelength of the out-of-plane localized surface plasmon resonance in hemispherical Ga NPs, deposited on silicon substrates, with oxide shell (Ga2O3) of different thickness. Thermal oxidation treatments, varying temperature and time, were carried out in order to increase experimentally the Ga2O3 shell thickness in the NPs. The optical, structural and chemical properties of the oxidized NPs have been studied by spectroscopic ellipsometry, scanning electron microscopy, grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy. A clear redshift of the peak wavelength is observed, barely affecting the intensity of the plasmon resonance. A controllable increase of the Ga2O3 thickness as a consequence of the thermal annealing is achieved. In addition, simulations together with ellipsometry results have been used to determine the oxidation rate, whose kinetics is governed by a logarithmic dependence. These results support the tunable properties of the plasmon resonance wavelength in Ga NPs by thermal oxidation at low temperatures without significant reduction of the plasmon resonance intensityThis research is supported by the MINECO (CTQ2014-53334-C2-2-R and MAT2016-80394-R) and Comunidad de Madrid (NANOAVANSENS ref. S2013/MIT-3029) projects. ARC acknowledges Ramón y Cajal program (under contract number RYC-2015-18047). FN acknowledges support from Marie Sklodowska-Curie grant agreement No 641899 from the European Union’s Horizon 2020 research and innovation programm

    The role of the oxide shell in the chemical functionalization of plasmonic gallium nanoparticles

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    S. Catalán-Gómez, M. Briones, A. Redondo-Cubero, F. J. Palomares, F. Nucciarelli, E. Lorenzo, J. L. Pau, "The role of the oxide shell in the chemical functionalization of plasmonic gallium nanoparticles", SPIE Optics + Optoelectronics Proc. SPIE 10231 (16 May 2017); doi: 10.1117/12.2265665; Copyright 2017 Society of Photo‑Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Plasmonic Ga nanoparticles (NPs) were thermally oxidized at low temperature in order to increase the native Ga 2 O 3 shell thickness and to improve their stability during the chemical functionalization. The optical, structural and chemical properties of the oxidized NPs have been studied by spectroscopic ellipsometry, scanning electron microscopy, grazing incidence X-ray diffraction and X-ray photoelectron spectroscopy. A clear redshift of the peak wavelength is observed with the increasing annealing time due to the Ga 2 O 3 thickness increase, and barely affecting the intensity of the plasmon resonance. This oxide layer enhances the stability of the NPs upon immersion in ethanol or water. The surface sensitivity properties of the as-grown and oxidized NPs were investigated by linking a thiol group from 6-Mercapto-1-hexanol through immersion. Ellipsometric spectra at the reversal polarization handedness (RPH) condition are in agreement with the Langmuir absorption model, indicating the formation of a thiol monolayer on the NPs

    Breaking the configurational anisotropy in Fe single crystal nanomagnets

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    In this work, we improve the ability to tailor the switching mechanism in nanomagnets by introducing an additional, highly controlled source of anisotropy: magnetocrystalline anisotropy. We analyze the vortex dynamics in single crystal Fe nanotriangles with different orientations of the crystalline axes. By experimental studies and simulation, we show that the angular dependence of the vortex annihilation field springs from the convolution of the crystalline and configurational anisotropies. In contrast, the remanence and the nucleation field present a much simpler behavior controlled by the existence of a single symmetry axis when shape and crystalline orientation are taken into account

    Size-selective breaking of the core-shell structure of gallium nanoparticles

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    This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after the 12 month embargo period provided that all the terms of the licence are adhered toCore-shell gallium nanoparticles (Ga NPs) have recently been proposed as an ultraviolet plasmonic material for different applications but only at room temperature. Here, the thermal stability as a function of the size of the NPs is reported over a wide range of temperatures. We analyze the chemical and structural properties of the oxide shell by x-ray photoelectron spectroscopy and atomic force microscopy. We demonstrate the inverse dependence of the shell breaking temperature with the size of the NPs. Spectroscopic ellipsometry is used for tracking the rupture and its mechanism is systematically investigated by scanning electron microscopy, grazing incidence x-ray diffraction and cathodoluminescence. Taking advantage of the thermal stability of the NPs, we perform complete oxidations that lead to homogenous gallium oxide NPs. Thus, this study set the physical limits of Ga NPs to last at high temperatures, and opens up the possibility to achieve totally oxidized NPs while keeping their sphericityThe research is supported by the MINECO (CTQ2014-53334-C2-2-R, CTQ2017-84309-C2-2-R, MAT2016-80394-R, MAT 2015-65274-R/FEDER and MAT2017-85089-C2-1-R) and Comunidad de Madrid (NANOAVANSENS ref. S2013/MIT-3029) projects. ARC acknowledges Ramón y Cajal program (under contract number RYC-2015-18047). FN acknowledges support from Marie Sklodowska-Curie grant agreement No. 641899 from the European Union´s Horizon 2020 research and innovation programm

    Assisted Reproductive Techniques in Multiple Sclerosis: Recommendations from an Expert Panel

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    Introduction Multiple sclerosis (MS) is mainly diagnosed in women of reproductive age. However, there is a paucity of guidelines jointly prepared by neurologists and gynaecologists on managing women with MS and the desire for motherhood. Therefore, in this review we propose recommendations for such cases, with an particular focus on those requiring assisted reproductive techniques (ART). Methods A group of seven MS experts (4 neurologists and 3 gynaecologists) came together for three discussion sessions to achieve consensus. Results The recommendations reported here focus on the importance of early preconception counselling, the management of disease-modifying therapies before and during ART procedures, important considerations for women with MS regarding ART (intrauterine insemination, in vitro fertilisation and oocyte cryopreservation) and the paramount relevance of multidisciplinary units to manage these patients. Conclusions Early preconception consultations are essential to individualising pregnancy management in women with MS, and an early, well-planned, spontaneous pregnancy should be the aim whenever possible. The management of women with MS and the desire for motherhood by multidisciplinary units is warranted to ensure appropriate guidance through the entire pregnancy.Merck, S.L.U., Madrid, Spain, an affiliate of Merck KGaA funded this work without participating in its design, data analysis or manuscript preparation. Merck, S.L.U also funded the journal’s Rapid Service Fee

    Remanence enhancement for stray field-based applications in arrays of crystalline nanomagnets

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    With the aim of achieving stable, substantial remanences adequate for exploitation in stray field-based applications, we report on the hysteresis behavior occurring in arrays of single-crystal Fe motifs, a-beam lithographed into prisms with triangular bases and different orientations of their magnetocrystalline axes with respect to the morphological symmetry axes. From both experimental and simulational analyses we recognize the fact that the magnetization reversal processes of our samples were mediated by motif-sized vortices. Their nucleation and annihilation fields and sites within the motifs, and their field-induced displacements, are discussed in terms of the magnetocrystalline and configurational anisotropies and inter-motif dipolar interactions. From our data, we conclude that reduced remanences as large as 0.85 (sufficient for the application requirements), protected by nucleation fields of several tens of Oe, can be produced in arrays where magnetocrystalline easy axes reinforce and partly compensate the easiest and hardest configurational ones, respectively. The angular dependence of the reduced remanence associated with interplay of these anisotropies corresponds to a symmetry reduction from the triaxial one linked to the triangular morphology down to an effective uniaxial one. We also identify, for the particular case of inter-nanoprism distances that are short in comparison with the dimensions of the motif base, a contribution to the remanence enhancement originating from the dipolar interactions

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Clave preliminar de las escamas de los peces de agua dulce de España, a nivel de familiaExito reproductor del Buitre leonado (Gyps fulvus) en NavarraAlimentación del Gavilán (Accipiter nisus) en la Isla de TenerifeEl Verdecillo (Serinus serinus): Tendencias en la estación de nidificación, en el tamaño del huevo y en la supervivencia.las batidas como método de censo en especiesde caza mayor: aplicación al caso del Jabalí (Sus scrofa L.) en la provincia de Burgos (Norte de España)La adquisición de madurez sexual en el camaleón común (Chamaeleo chamaeleon)Nuevas citas de Hemidactylus turcicus en la provincia de CáceresLa focha común (Fulica atra) en la isla de Gran Canaria: nueva especie nidificante en el archipiélago CanarioTraslado de huevos en incubación por la urraca (Pica pica)Predación de Falco peregrinus sobre Oryctolagus cuniculusCuatro nuevas especies de aves para Bolivia.Sobre la utilización de nidos de golondrina común abandonados.Parasitismo múltiple del críalo (Clamator glandarius)Predación del topo de rio (Galemys pyrenaicus, Geoffroy 1811) por parte de la lechuza común (Tyto alba, Scopoli 1769)Predación del zorro (Vulpes vulpes) sobre un pollo de buitre leonado (Gyps fulvus).Vulpes vulpes L. criando en una colonia de marmota (Marmota marmota L.) en el pirineo de LéridaObservaciones sobre la incidencia de Rattus (Fischer, 1803) en los cultivos ibéricos de caña de azúcaSituación actual de la jutiita de la tierra Capromys sanfelipensis (Rodentia, Mammalia)Notas sobre la intraducción y expansión de la ardilla común en Sierra Nevada, sureste de EspañaPeer reviewe
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