34 research outputs found
Transparent yttrium hydride thin films prepared by reactive sputtering
Metal hydrides have earlier been suggested for utilization in solar cells.
With this as a motivation we have prepared thin films of yttrium hydride by
reactive magnetron sputter deposition. The resulting films are metallic for low
partial pressure of hydrogen during the deposition, and black or
yellow-transparent for higher partial pressure of hydrogen. Both metallic and
semiconducting transparent YHx films have been prepared directly in-situ
without the need of capping layers and post-deposition hydrogenation. Optically
the films are similar to what is found for YHx films prepared by other
techniques, but the crystal structure of the transparent films differ from the
well-known YH3 phase, as they have an fcc lattice instead of hcp
A genome-wide association study of rheumatoid arthritis without antibodies against citrullinated peptides
Introduction. Rheumatoid arthritis (RA) patients can be classified based on presence or absence of anticitrullinated peptide antibodies (ACPA) in their serum. This heterogeneity among patients may reflect important biological differences underlying the disease process. To date, the majority of genetic studies have focused on the ACPA-positive group. Therefore, our goal was to analyse the genetic risk factors that contribute to ACPA-negative RA. Methods. We performed a large-scale genome-wide association study (GWAS) in three Caucasian European cohorts comprising 1148 ACPA-negative RA patients and 6008 controls. All patients were screened using the Illumina Human Cyto-12 chip, and controls were genotyped using different genome-wide platforms. Population-independent analyses were carried out by means of logistic regression. Meta-analysis with previously published data was performed as follow-up for selected signals (reaching a total of 1922 ACPA-negative RA patients and 7087 controls). Imputation of classical HLA alleles, aminoacid residues and single nucleotide polymorphisms was undertaken. Results. The combined analysis of the studied cohorts resulted in identification of a peak of association in the HLA-region and several suggestive non-HLA associations. Meta-analysis with previous reports confirmed the association of the HLA region with this subset and an observed association in the CLYBL locus remained suggestive. The imputation and deep interrogation of the HLA region led to identification of a two aminoacid model (HLA-B at position 9 and HLA-DRB1 at position 11) that accounted for the observed genome-wide associations in this region. Conclusions. Our study shed light on the influence of the HLA region in ACPA-negative RA and identified a suggestive risk locus for this condition
IGFBP3 Colocalizes with and Regulates Hypocretin (Orexin)
Background: The sleep disorder narcolepsy is caused by a vast reduction in neurons producing the hypocretin (orexin) neuropeptides. Based on the tight association with HLA, narcolepsy is believed to result from an autoimmune attack, but the cause of hypocretin cell loss is still unknown. We performed gene expression profiling in the hypothalamus to identify novel genes dysregulated in narcolepsy, as these may be the target of autoimmune attack or modulate hypocretin gene expression. Methodology/Principal Findings: We used microarrays to compare the transcriptome in the posterior hypothalamus of (1) narcoleptic versus control postmortem human brains and (2) transgenic mice lacking hypocretin neurons versus wild type mice. Hypocretin was the most downregulated gene in human narcolepsy brains. Among many additional candidates, only one, insulin-like growth factor binding protein 3 (IGFBP3), was downregulated in both human and mouse models and coexpressed in hypocretin neurons. Functional analysis indicated decreased hypocretin messenger RNA and peptide content, and increased sleep in transgenic mice overexpressing human IGFBP3, an effect possibly mediated through decrease
Deposition of magnesium hydride thin films using radio frequency reactive sputtering
Reactive sputter deposition of MgHx thin films was performed using mixed hydrogenâargon plasma. This technique allows in-situ deposition of metal hydride films in contrast to the commonly applied ex-situ hydrogenation of metallic films. Partly transparent films were obtained and the formation of crystalline MgH2 could be observed for thicknesses above about 200 nm. The formation of some metallic Mg in the films could not be avoided. Increased hydrogen loading by increased pressure, H2:Ar ratio or reduced power produced films of porous structure that easily oxidise. More densely packed films remain stable for several months of air exposure. Post-deposition treatments in H-plasma showed evidence of hydrogenation of deposited films without the use of a catalysing capping film. Film properties are studied by X-ray diffraction, scanning electron microscopy and by optical and resistivity measurements
Co-induction of neuronal interferon-gamma and nitric oxide synthase in rat motor neurons after axotomy: a role in nerve repair or death?
Induction of an interferon-gamma-like molecule, previously isolated from neurons (N-IFN-gamma), and of the neuronal isoform I of the synthetic enzyme of the free radical nitric oxide, nitric oxide synthase I, as well as of NADPH-diaphorase, were examined in axotomized dorsal motor vagal and hypoglossal neurons. Unilateral transection of the vagal and hypoglossal nerves was performed in the same rat and an induction of N-IFN-gamma and nitric oxide synthase I immunostaining as well as NADPH-diaphorase histochemical positivity was observed in the ipsilateral motoneurons after 2-4 days. The immuno- and enzyme-histochemical positivities were much stronger in the dorsal motor vagal neurons than in hypoglossal neurons. Two and 4 weeks after axotomy N-IFN-gamma immunoreactivity and NADPH-diaphorase positivity persisted in the former, but started to decrease in the latter neurons. Previous data have shown that 23 weeks after nerve transection the majority of the dorsal motor vagal neurons are lost, while the major ity of the hypoglossal neurons survive. The high and persistent expression of N-IFN-gamma and nitric oxide synthase I after axotomy in the dorsal motor vagal neurons, that are largely destined to die, indicates that the co-induction of these two molecules may be implicated in the pathogenesis of neuronal degeneration
Vibrational Properties of CaAlH <sub>5</sub> and a-AlH <sub>3</sub> with Different AlH <sub>6</sub> Networks Studied by Inelastic Neutron Scattering
Replication of association of the interleukin 23 receptor rs1343151 variant with rheumatoid arthritis in Caucasian sample sets
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