154 research outputs found

    Strain-driven elastic and orbital-ordering effects on thickness-dependent properties of manganite thin films

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    We report on the structural and magnetic characterization of (110) and (001) La2/3Ca1/3MnO3 (LCMO) epitaxial thin films simultaneously grown on (110) and (001)SrTiO3 substrates, with thicknesses t varying between 8 nm and 150 nm. It is found that while the in-plane interplanar distances of the (001) films are strongly clamped to those of the substrate and the films remain strained up to well above t=100 nm, the (110) films relax much earlier. Accurate determination of the in-plane and out-of-plane interplanar distances has allowed concluding that in all cases the unit cell volume of the manganite reduces gradually when increasing thickness, approaching the bulk value. It is observed that the magnetic properties (Curie temperature and saturation magnetization) of the (110) films are significantly improved compared to those of (001) films. These observations, combined with 55Mn-nuclear magnetic resonance data and X-ray photoemission spectroscopy, signal that the depression of the magnetic properties of the more strained (001)LCMO films is not caused by an elastic deformation of the perovskite lattice but rather due to the electronic and chemical phase separation caused by the substrate-induced strain. On the contrary, the thickness dependence of the magnetic properties of the less strained (110)LCMO films are simply described by the elastic deformation of the manganite lattice. We will argue that the different behavior of (001) and (110)LCMO films is a consequence of the dissimilar electronic structure of these interfaces.Comment: 16 pages, 15 figure

    Ala397Asp Mutation of Myosin VIIA Segregating in a Spanish Family with Usher Syndrome Type Ib

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    [EN] In the current study, 12 Spanish families affected by type-I Usher syndrome, that was previously linked to chromosome 11q, were screened for the presence of mutations in the N-terminal coding portion of the motor domain of the myosin VIIA gene by single-strand conformation polymorphism analysis of the first 14 exons. A mutation (Ala397Asp) segregating with the disease was identified, and several polymorphisms were also detected. It is presumed that the other USH1B mutations in these families could be located in the unscreened regions of the gene.The authors would like to thank the Fondo de Investigaciones Sanitarias (FISS n0 95/1814), the ONCE and the Fundación ONCE for financial support. We acknowledge patients and their family members, as well as the Asociación de retinosis pigmentaria de la Comunidad Valenciana and the FAARPEE, for their help and cooperation.Espinós-Armero, CÁ.; Millán, JM.; Sánchez, F.; Beneyto, M.; Nájera, C. (1998). Ala397Asp Mutation of Myosin VIIA Segregating in a Spanish Family with Usher Syndrome Type Ib. Human Genetics. 102(6):691-694. https://doi.org/10.1007/s004390050763691694102

    Platinum nanoparticles stabilized by N-heterocyclic thiones. Synthesis and catalytic activity in mono- and di-hydroboration of alkynes

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    N-Heterocyclic Thiones (NHT) proved to be efficient ligands for the stabilization of small platinum nanoparticles (1.3-1.7 nm), synthesized by decomposition of [Pt(dba)2], under a H2 atmosphere, in the presence of variable sub-stoichiometric amounts of the NHT. Full characterization by means of TEM, HR-TEM, NMR, ICP, TGA and XPS have been carried out, providing information about the nature of the metal nanoparticles and the interaction of the NHT ligands to the metal surface. Importantly, DFT calculations indicate that some NHT ligands interact with the metal through the C[double bond, length as m-dash]C double bond of the imidazole fragment in addition to the sulfur atom, thus providing additional stabilization to the nanoparticles. According to XPS, TGA and ICP techniques, the surface coverage by the ligand increases by decreasing the size of the substituents on the nitrogen atom. The platinum nanoparticles have been used as catalyst in the hydroboration of alkynes. The most active system is that with a less covered surface area lacking an interaction of the ligand by means of the C[double bond, length as m-dash]C double bond. This catalyst hydroborates alkynes with excellent selectivities towards the monoborylated anti-Markovnikov product (vinyl-boronate) when one equiv. of borane is used. Very interestingly, aliphatic alkynes undergo a second hydroborylation process leading to the corresponding 1,1- and 1,2-diboroylated species with good selectivities towards the former.España MINECO (Projects CTQ2016-76267-P, CTQ2016-80814-R and CTQ2016- 81797-REDC)España Junta de Andalucía Project FQM-212

    Genetic analyses of celiac disease in a Spanish population confirm association with CELIAC3 but not with CELIAC4

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    [EN] Genetic predisposition to celiac disease (CD) is determined primarily by the human leukocyte antigen (HLA) genes (CELIAC1 region; 6p21), although many loci are involved in disease susceptibility. First, we have analysed a large series of CD patients from the Spanish Mediterranean region who had previously been characterised for the HLA complex. We have investigated how relevant regions contribute to CD susceptibility: CELIAC3 (CD28/CTLA4/ICOS region on 2q33) and CELIAC4 (19p13) as well as the tumour necrosis factor alpha (TNF-alpha) and the linfotoxin loci by case-control and association analyses. We highlight the association with the +49*A allele of cytotoxic T-lymphocyte-associated antigen 4 locus (P = 0.01), and the -308*A of TNF-alpha locus (P = 0.0008) in DQ2 individuals, although an independent role for TNF-alpha as risk factor has not been proven. Moreover, we do not confirm the association with the CELIAC4 region polymorphisms described in other populations.We are grateful for the kind collaboration of patients and families and Asociación de Celíacos de la Comunidad Valenciana (ACECOVA). This work was supported by the Fondo de Investigacio¿n Sanitaria (grant PI02573) and by the CSIC Intramural Frontiers Project (PROFICEL). ED holds a fellowship from the Fundacio¿n La Fe. English text revised by F. BarracloughCapilla, A.; Donat, E.; Planelles, D.; Espinós-Armero, CÁ.; Ribes-Koninckx, C.; Palau, F. (2007). Genetic analyses of celiac disease in a Spanish population confirm association with CELIAC3 but not with CELIAC4. Tissue Antigens. 70(4):324-329. https://doi.org/10.1111/j.1399-0039.2007.00899.x32432970

    Genetic epidemiology of the Charcot-Marie-Tooth in the Spanish Gypsy population: the Hereditary Motor and Sensory Neuropathy type Russe in depth

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    [EN] Four private mutations responsible for three forms demyelinating of Charcot-Marie-Tooth (CMT) or hereditary motor and sensory neuropathy (HMSN) have been associated with the Gypsy population: the NDRG1 p.R148X in CMT type 4D (CMT4D/HMSN-Lom); p.C737_P738delinsX and p.R1109X mutations in the SH3TC2 gene (CMT4C); and a G>C change in a novel alternative untranslated exon in the HK1 gene causative of CMT4G (CMT4G/HMSN-Russe). Here we address the findings of a genetic study of 29 Gypsy Spanish families with autosomal recessive demyelinating CMT. The most frequent form is CMT4C (57.14%), followed by HMSN-Russe (25%) and HMSN-Lom (17.86%). The relevant frequency of HMSN-Russe has allowed us to investigate in depth the genetics and the associated clinical symptoms of this CMT form. HMSN-Russe probands share the same haplotype confirming that the HK1 g.9712G>C is a founder mutation, which arrived in Spain around the end of the 18th century. The clinical picture of HMSN-Russe is a progressive CMT disorder leading to severe weakness of the lower limbs and prominent distal sensory loss. Motor nerve conduction velocity was in the demyelinating or intermediate range.We thank all patients and their relatives for their kind collaboration. We also thank Drs G. Glover, R. Vilches, F. Galan, and C. Diaz for referring patients for genetic analysis. We also acknowledge F Barraclough for English corrections. This work was supported by the Instituto de Salud Carlos III (ISCIII) (grants number PI08/90857, PI08/0889, CP08/00053 and PS09/00095) co-funded with FEDER funds and by the ISCIII-IRDiRC Programme (TREAT-CMT grant). C. E. has a 'Miguel Servet' contract funded by the ISCIII. Both Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER) and Centro de Investigacion Biomedica en Red de Enfermedades Neurodegenerativas (CIBERNED) are initiative from the ISCIII.Sevilla, T.; Martínez-Rubio, D.; Márquez, C.; Paradas, C.; Colomer, J.; Jaijo, T.; Millán, J.... (2013). Genetic epidemiology of the Charcot-Marie-Tooth in the Spanish Gypsy population: the Hereditary Motor and Sensory Neuropathy type Russe in depth. Clinical Genetics. 83(6):565-570. https://doi.org/10.1111/cge.1201556557083

    Hypopituitarism and pregnancy : clinical characteristics, management and pregnancy outcome

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    Altres ajuts: Acord transformatiu CRUE-CSICAltres ajuts: Open Access Funding provided by Universitat Autonoma de Barcelona.Purpose: To describe the clinical characteristics, management and pregnancy outcome of women with prepregnancy hypopituitarism (HYPO) that received care at our center. Methods: Retrospective study describing 12 pregnancies in women with prepregnancy HYPO (two or more pituitary hormonal deficiencies under replacement treatment) that received care during pregnancy at Hospital Santa Creu i Sant Pau. Clinical characteristics, management and pregnancy outcome were systematically collected. Results: Average patients' age was 35 years and HYPO duration at the beginning of pregnancy was 19 years. The most frequent cause of HYPO was surgical treatment of a sellar mass (8 pregnancies). Eight pregnancies were in primigravid women and 10 required assisted reproductive techniques. The hormonal deficits before pregnancy were as follows: GH in 12 women, TSH in 10, gonadotropin in 9, ACTH in 5 and ADH in 2. All deficits were under hormonal substitution except for GH deficit in 4 pregnancies. During pregnancy, 4 new deficits were diagnosed. The dosage of replacement treatment for TSH, ACTH and ADH deficits was increased and GH was stopped. Average gestational age at birth was 40 weeks, gestational weight gain was excessive in 9 women, 8 patients required induction/elective delivery and cesarean section was performed in 6. Average birthweight was 3227 g. No major complications were observed. Five women were breastfeeding at discharge. Conclusions: In this group of women with long-standing HYPO, with careful clinical management (including treatment of new-onset hormonal deficits) pregnancy outcome was satisfactory but with a high rate of excessive gestational weight gain and cesarean section

    Slender double-tube ultra-high strength concrete-filled tubular columns under ambient temperature and fire

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    This paper presents the results of an experimental campaign where both the room temperature and the fire resistance of six double-tube concrete filled steel tubular slender columns with different combinations of concrete strength are studied. Firstly, the ultimate axial load of the specimens at room temperatura was experimentally obtained and afterwards the fire resistance of such columns subjected to a 20% of their load bearing capacity was measured. Given the reduced number of experimental results found in the literature on slender concrete filled tubular columns with double steel tubular cross-sections, the main objective of this paper is to compare the behaviour of such innovative cross-sections under ambient and high temperatures. The influence of filling the inner ring with concrete on the fire performance of these columns is studied in this paper, as well as the variation of thicknesses of the outer and inner steel tubes. Despite the fact that the tested columns are not covered by the scope of Eurocode 4, the current simple calculation models were applied in this paper in order to assess the validity of the standard to this typology of columns, unsafe results being found.The authors would like to express their sincere gratitude to the Spanish Ministry of Economy and Competitivity through the project BIA2012-33144 and to the European Community for the FEDER funds.Romero, ML.; Espinós Capilla, A.; Portoles Flaj, JM.; Hospitaler Pérez, A.; Ibáñez Usach, C. (2015). Slender double-tube ultra-high strength concrete-filled tubular columns under ambient temperature and fire. Engineering Structures. 99:536-545. https://doi.org/10.1016/j.engstruct.2015.05.026S5365459

    Experiencia inicial del uso de SelectMDx® en el diagnóstico de cáncer de próstata en un entorno de práctica clínica habitual «real-world evidence».

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    Introducción El uso de biomarcadores en la detección del cáncer de próstata (CP) puede disminuir el sobrediagnóstico y sobretratamiento de CP no significativos. Analizamos la utilidad y aplicabilidad del marcador SelectMDx® en un entorno de práctica clínica habitual. Material y métodos Estudio retrospectivo de 48 pacientes evaluados mediante el test SelectMDx® entre julio de 2017 y abril de 2019. Los pacientes se estratificaron en dos grupos según el riesgo estimado por el test de CP clínicamente significativo (CP-CS): 2%. Los resultados se expresaron en función de los antecedentes de biopsia prostática (BP) y resonancia magnética multiparamétrica (RMmp). Resultados En pacientes con BP negativa y RMmp normal/dudosa el riesgo fue 2% presentaron un CP-CS. De los 14 pacientes sin BP ni RMmp previas, 9 presentaron un riesgo 2%. En el resto de subgrupos el número de pacientes es pequeño como para poder extraer conclusiones. En todos los casos con tacto rectal patológico el test demostraba un riesgo de padecer CP > 2%. Conclusión SelectMDx® es un test prometedor para detectar pacientes con un riesgo muy bajo de CP-CS, especialmente en pacientes con sospecha de CP con o sin BP negativas, en los que la RMmp muestre un resultado normal/dudoso. La presencia de un tacto rectal patológico puede condicionar el resultado del test.pre-print203 K

    Influence of the chemical and electronic structure on the electrical behavior of zirconium oxynitride films

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    This work is devoted to the investigation of decorative zirconium oxynitride, ZrOxNy, films prepared by dc reactive magnetron sputtering, using a 17:3 nitrogen-to-oxygen-ratio gas mixture. The color of the films changed from metallic-like, very bright yellow pale, and golden yellow, for low gas mixture flows [from 0 to about 9 SCCM (SCCM denotes cubic centimeter per minute at STP)] to red brownish for intermediate gas flows (values up to 12 SCCM). Associated to this color change there is a significant decrease of brightness. With further increase of the reactive gas flow, the color of the samples changed from red brownish to dark blue (samples prepared with 13 and 14 SCCM). The films deposited with gas flows above 14 SCCM showed only apparent colorations due to interference effects. This change in optical behavior from opaque to transparent (characteristic of a transition from metallic to insulating-type materials), promoted by the change in gas flow values, revealed that significant changes were occurring in the film structure and electronic properties, thus opening new potential applications for the films, beyond those of purely decorative ones. Taking this into account, the electrical behavior of the films was investigated as a function of the reactive gas flow and correlated with the observed chemical, electronic, and structural features. The variations in composition disclosed the existence of four different zones, which were correlated to different crystalline structures. For the so-called zone I, x-ray diffraction revealed the development of films with a B1 NaCl face-centered cubic zirconium nitride-type phase, with some texture changes. Increasing the reactive gas flow, the structure of the films is that of a poorly crystallized over-stoichiometric nitride phase, which may be similar to that of Zr3N4, but with some probable oxygen inclusions within nitrogen positions. This region was characterized as zone II. Zone III was indexed as an oxynitride-type phase, similar to that of gamma-Zr2ON2 with some oxygen atoms occupying some of the nitrogen positions. Finally, occurring at the highest flow rates, zone IV was assigned to a ZrO2 monoclinic-type structure. The composition/structure variations were consistent with the chemical bonding analysis carried out by x-ray photoelectron spectroscopy, which showed oxygen doping in both Zr3N4- and ZrN-type grown films. The electronic properties of the films exhibited significant changes from zone to zone. Resistivity measurements revealed a very wide range of values, varying from relatively highly conductive materials (for zone I) with resistivity values around few hundreds of micro-ohm cm to highly insulating films within zones III and IV, which presented resistivity values in the order of 1015 micro-ohm cm. Regarding zone II, corresponding to oxygen doped Zr3N4-type compounds, the observed behavior revealed resistivity values increasing steeply from about 103 up to 1015 micro-ohm cm, indicating a systematic transition from metallic to insulating regimes.Fundação para a Ciência e Tecnologia (FCT) -PTDC/CTM/69362/2006, SFRH/BD/31907/2006 and SFRH/BBD/27114/2006

    Exacerbated atherosclerosis in progeria is prevented by progerin elimination in vascular smooth muscle cells but not endothelial cells

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    Hutchinson-Gilford progeria syndrome (HGPS) is a rare disease caused by the expression of progerin, a mutant protein that accelerates aging and precipitates death. Given that atherosclerosis complications are the main cause of death in progeria, here we investigated whether progerin-induced atherosclerosis is prevented in HGPSrev-Cdh5-CreERT2 and HGPSrev-SM22α-Cre mice with progerin suppression in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), respectively. HGPSrev-Cdh5-CreERT2 mice were undistinguishable from HGPSrev mice with ubiquitous progerin expression, in contrast with the ameliorated progeroid phenotype of HGPSrev-SM22α-Cre mice. To study atherosclerosis, we generated atheroprone mouse models by overexpressing a PCSK9 gain-of-function mutant. While HGPSrev-Cdh5-CreERT2 and HGPSrev mice developed a similar level of excessive atherosclerosis, plaque development in HGPSrev-SM22α-Cre mice was reduced to wild-type levels. Our studies demonstrate that progerin suppression in VSMCs, but not in ECs, prevents exacerbated atherosclerosis in progeroid mice
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