269 research outputs found
First-principles simulations of lithium melting: Stability of the bcc phase close to melting
4 páginas, 2 figuras.We report large-scale first-principles simulations of melting of four different phases of Li at pressures ranging from 0 to 50 GPa. We find excellent agreement with existing experimental data at low pressures, and confirm that above 10 GPa the melting line develops a negative slope, in parallel to what occurs for Na at 30 GPa. Surprisingly, our results indicate that the melting temperature of the bcc phase is always higher than that of fcc Li, suggesting the intriguing possibility of the existence of a narrow field of bcc stability separating the fcc and liquid phases, as predicted by Alexander and McTague.The work of E. R. H. is supported by the Spanish Ministry of Science and Innovation through Project No. FIS2006-12117-C04-01; A. B. thanks GV-UPV/EHU for Project No. IT-366-07. The work of D. A. was conducted as part of an EURYI scheme grant as provided by EPSRC-GB.Peer reviewe
Aislamiento y caracterización de cepas vinicas de Saccharomyces cereviciae del valle de Casablanca (Chile)
Se aislaron cepas vínicas nativas de uvas procedentes del valle de Casablanca, región productora de vinos de calidad, mediante fermentación natural del mostoen presencia de metabisulfito de potasio como agente selectivo.Los análisis morfológicos y fisiológicos realizados, a parlir de colonias aisladas obtenidas del mosto al término del proceso de fermentación, permitieron establecer que, aproximadamente, un 90% de ellas correspondían a cepas de levaduras ascosporógenas de Saccharomyces cerevisiae. Además, al determinar el fenotipo «killer» de estas cepas, se encontró que un 40% de ellas eran productoras de toxina «killer».Las evaluaciones enológicas practicadas a un subconjunto de estas cepas, presentaron propiedades similares a cepas vínicas comerciales de S. cerevisiae.La caracterización molecular de éstas, mediante electroforesis de campo pulsado, permitió establecer la presencia de, al menos, cuatro diferentes cariotipos electrforéticos, con un tamaño estimado del genoma nuclear entre los 13.000 a los 21.000 kb
Cardiotrophin-1 defends the liver against ischemia-reperfusion injury and mediates the protective effect of ischemic preconditioning
Ischemia-reperfusion (I/R) liver injury occurs when blood flow is restored after prolonged ischemia. A short interruption of blood flow (ischemic preconditioning [IP]) induces tolerance to subsequent prolonged ischemia through ill-defined mechanisms. Cardiotrophin (CT)-1, a cytokine of the interleukin-6 family, exerts hepatoprotective effects and activates key survival pathways like JAK/STAT3. Here we show that administration of CT-1 to rats or mice protects against I/R liver injury and that CT-1-deficient mice are exceedingly sensitive to this type of damage. IP markedly reduced transaminase levels and abrogated caspase-3 and c-Jun-NH2-terminal kinase activation after I/R in normal mice but not in CT-1-null mice. Moreover, the protective effect afforded by IP was reduced by previous administration of neutralizing anti-CT-1 antibody. Prominent STAT3 phosphorylation in liver tissue was observed after IP plus I/R in normal mice but not in CT-1-null mice. Oxidative stress, a process involved in IP-induced hepatoprotection, was found to stimulate CT-1 release from isolated hepatocytes. Interestingly, brief ischemia followed by short reperfusion caused mild serum transaminase elevation and strong STAT3 activation in normal and IL-6-deficient mice, but failed to activate STAT3 and provoked marked hypertransaminasemia in CT-1-null animals. In conclusion, CT-1 is an essential endogenous defense of the liver against I/R and is a key mediator of the protective effect induced by IP
Nanosistemas a base de poliésteres
Amplia presentacion de los:
Nanosistemas a base de
poliésteres, desarrollando todas las posibilidades de estos compuestos que constituyen tal vez los polímeros mas frecuentemente utilizados por estar, algunos de ellos, autorizado su empleo por las agen-
cias regulatorias
Polymorphisms in genes related to the complement system and antibody-mediated cardiac allograft rejection
[Abstract] Background. Heart transplantation (HT) is a life-saving treatment for patients with end-stage heart failure. One of the main problems after HT is the humoral response termed antibody-mediated rejection (AMR). Complement activation plays a key role in AMR contributing to graft damage. The aim of this study was to analyze genetic variants in genes related to the complement pathways that could be associated with the development of AMR.
Methods. Analysis of 51 genes related to the complement pathway was performed by next-generation sequencing in 46 HT recipients, 23 with and 23 without AMR. Statistical analysis was performed with SNPstats and R.
Results. We identified 2 single nucleotide polymorphisms, 1 in the mannose-binding lectin 2 gene (p.Gly54Asp-MBL2) and 1 in the complement factor properdin gene (p.Asn428(p=)-CFP), that showed significant association with the absence and development of AMR, respectively. Moreover, the presence of the rare allele in p.Gly54Asp-MBL2 control patients correlated with an immunodeficiency of mannose-binding lectin (6.24 ng/ml vs 207.50 ng/ml, p < 0.01), whereas the presence of the rare allele p.Asn428(p=)-CFP in patients with AMR correlated with higher levels of properdin protein (14.65 μg/ml vs 10.77 μg/ml, p < 0.05).
Conclusions. AMR is a complex phenotype affected by many recipient factors. Variants in p.Gly54Asp-MBL2 and p.Asn428(p=)-CFP genes, encoding mannose-binding lectin 2 and properdin, may influence the risk of AMR.Instituto de Salud Carlos III; PI13/0217
AGT haplotype in ITGA4 gene is related to antibody-mediated rejection in heart transplant patients
[Abstract] Introduction.
One of the main problems involved in heart transplantation (HT) is antibody-mediated rejection
(AMR). Many aspects of AMR are still unresolved, including its etiology, diagnosis and
treatment. In this project, we hypothesize that variants in genes involved in B-cell biology in
HT patients can yield diagnostic and prognostic information about AMR.
Methods.
Genetic variants in 61 genes related to B-cell biology were analyzed by next generation
sequencing in 46 HT patients, 23 with and 23 without AMR.
Results.
We identified 3 single nucleotide polymorphisms in ITGA4 gene (c.1845G>A, c.2633A>G,
and c.2883C>T) that conformed the haplotype AGT-ITGA4. This haplotype is associated
with the development of AMR. Moreover, AMR patients with the haplotype AGT-ITGA4
present lower levels of integrin α-4 in serum samples compared to the reference GAC haplotype
in control patients.
Conclusion.
We can conclude that polymorphisms in genes related to the biology of B-cells could have
an important role in the development of AMR. In fact, the AGT haplotype in ITGA4 gene
could potentially increase the risk of AMR.Instituto de Salud Carlos III; PI13/0217
Selective inhibition of HDAC6 regulates expression of the oncogenic driver EWSR1-FLI1 through the EWSR1 promoter in Ewing sarcoma
Ewing sarcoma (EWS) is an aggressive bone and soft tissue tumor of children and young adults in which the principal driver is a fusion gene, EWSR1-FLI1. Although the essential role of EWSR1-FLI1 protein in the regulation of oncogenesis, survival, and tumor progression processes has been described in-depth, little is known about the regulation of chimeric fusion-gene expression. Here, we demonstrate that the active nuclear HDAC6 in EWS modulates the acetylation status of specificity protein 1 (SP1), consequently regulating the SP1/P300 activator complex binding to EWSR1 and EWSR1-FLI1 promoters. Selective inhibition of HDAC6 impairs binding of the activator complex SP1/P300, thereby inducing EWSR1-FLI1 downregulation and significantly reducing its oncogenic functions. In addition, sensitivity of EWS cell lines to HDAC6 inhibition is higher than other tumor or non-tumor cell lines. High expression of HDAC6 in primary EWS tumor samples from patients correlates with a poor prognosis in two independent series accounting 279 patients. Notably, a combination treatment of a selective HDAC6 and doxorubicin (a DNA damage agent used as a standard therapy of EWS patients) dramatically inhibits tumor growth in two EWS murine xenograft models. These results could
lead to suitable and promising therapeutic alternatives for patients with EWS.Research in the E.D.A. lab is supported by Asociación Española Contra el Cáncer (AECC), the Ministry of Science of Spain-FEDER (CIBERONC, PI1700464, PI2000003, RD06/0020/0059)S. D.G.D. and L.H.P. are supported by CIBERONC (CB16/12/00361). D.G.D., M.J.R. and L.H.P. are PhD researchers funded by the Consejería de Salud, Junta de Andalucía (PI-0197-2016, ECAI F2-0012-2018 and PI-0013-2018, respectively).Peer reviewe
The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic
data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data
release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median
z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar
spectra, along with the data presented in previous data releases. These spectra
were obtained with the new BOSS spectrograph and were taken between 2009
December and 2011 July. In addition, the stellar parameters pipeline, which
determines radial velocities, surface temperatures, surface gravities, and
metallicities of stars, has been updated and refined with improvements in
temperature estimates for stars with T_eff<5000 K and in metallicity estimates
for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars
presented in DR8, including stars from SDSS-I and II, as well as those observed
as part of the SDSS-III Sloan Extension for Galactic Understanding and
Exploration-2 (SEGUE-2).
The astrometry error introduced in the DR8 imaging catalogs has been
corrected in the DR9 data products. The next data release for SDSS-III will be
in Summer 2013, which will present the first data from the Apache Point
Observatory Galactic Evolution Experiment (APOGEE) along with another year of
data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at
http://www.sdss3.org/dr
The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III
The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with
new instrumentation and new surveys focused on Galactic structure and chemical
evolution, measurements of the baryon oscillation feature in the clustering of
galaxies and the quasar Ly alpha forest, and a radial velocity search for
planets around ~8000 stars. This paper describes the first data release of
SDSS-III (and the eighth counting from the beginning of the SDSS). The release
includes five-band imaging of roughly 5200 deg^2 in the Southern Galactic Cap,
bringing the total footprint of the SDSS imaging to 14,555 deg^2, or over a
third of the Celestial Sphere. All the imaging data have been reprocessed with
an improved sky-subtraction algorithm and a final, self-consistent photometric
recalibration and flat-field determination. This release also includes all data
from the second phase of the Sloan Extension for Galactic Understanding and
Evolution (SEGUE-2), consisting of spectroscopy of approximately 118,000 stars
at both high and low Galactic latitudes. All the more than half a million
stellar spectra obtained with the SDSS spectrograph have been reprocessed
through an improved stellar parameters pipeline, which has better determination
of metallicity for high metallicity stars.Comment: Astrophysical Journal Supplements, in press (minor updates from
submitted version
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