37 research outputs found
Transport, optical and electronic properties of the half metal CrO2
The electronic structure of CrO_2 is critically discussed in terms of the
relation of existing experimental data and well converged LSDA and GGA
calculations of the electronic structure and transport properties of this half
metal magnet, with a particular emphasis on optical properties. We find only
moderate manifestations of many body effects. Renormalization of the density of
states is not large and is in the typical for transition metals range. We find
substantial deviations from Drude behavior in the far-infrared optical
conductivity. These appear because of the unusually low energy of interband
optical transitions. The calculated mass renormalization is found to be rather
sensitive to the exchange-correlation functional used and varies from 10%
(LSDA) to 90% (GGA), using the latest specific heat data. We also find that
dressing of the electrons by spin fluctuations, because of their high energy,
renormalizes the interband optical transition at as high as 4 eV by about 20%.
Although we find no clear indications of strong correlations of the Hubbard
type, strong electron-magnon scattering related to the half metallic band
structure is present and this leads to a nontrivial temperature dependence of
the resistivity and some renormalization of the electron spectra.Comment: 9 Revtex 2 column pages, including 8 postscript figures. Two more
figures are included in the submission that are not embedded in the paper,
representing DOS and bandstructure of the paramagnetic CrO
New national and regional Annex I Habitat records: from #60 to #82
New Italian data on the distribution of the Annex I Habitats are reported in this contribution. Specifically, 8 new occurrences in Natura 2000 sites are presented and 49 new cells are added in the EEA 10 km Ă 10 km reference grid. The new data refer to the Italian administrative regions of Campania, Calabria, Marche, Piedmont, Sardinia, Sicily, Tuscany and Umbria. ReleveÌs and figures are provided as Supplementary material respectively 1 and 2. Copyright Antonio Morabito et al
Promoter polymorphism -119C/G in MYG1 (C12orf10) gene is related to vitiligo susceptibility and Arg4Gln affects mitochondrial entrance of Myg1
<p>Abstract</p> <p>Background</p> <p><it>MYG1 </it>(<it>Melanocyte proliferating gene 1</it>, also C12orf10 in human) is a ubiquitous nucleo-mitochondrial protein, involved in early developmental processes and in adult stress/illness conditions. We recently showed that <it>MYG1 </it>mRNA expression is elevated in the skin of vitiligo patients. Our aim was to examine nine known polymorphisms in the <it>MYG1 </it>gene, to investigate their functionality, and to study their association with vitiligo susceptibility.</p> <p>Methods</p> <p>Nine single nucleotide polymorphisms (SNPs) in the <it>MYG1 </it>locus were investigated by SNPlex assay and/or sequencing in vitiligo patients (n = 124) and controls (n = 325). <it>MYG1 </it>expression in skin biopsies was detected by quantitative-real time PCR (Q-RT-PCR) and polymorphisms were further analysed using luciferase and YFP reporters in the cell culture.</p> <p>Results</p> <p>Control subjects with -119G promoter allele (rs1465073) exhibited significantly higher <it>MYG1 </it>mRNA levels than controls with -119C allele (<it>P </it>= 0.01). Higher activity of -119G promoter was confirmed by luciferase assay. Single marker association analysis showed that the -119G allele was more frequent in vitiligo patients (47.1%) compared to controls (39.3%, <it>P </it>< 0.05, OR 1.37, 95%CI 1.02-1.85). Analysis based on the stage of progression of the vitiligo revealed that the increased frequency of -119G allele occurred prevalently in the group of patients with active vitiligo (n = 86) compared to the control group (48.2% <it>versus </it>39.3%, <it>P </it>< 0.05; OR 1.44, 95%CI 1.02-2.03). Additionally, we showed that glutamine in the fourth position (in Arg4Gln polymorphism) completely eliminated mitochondrial entrance of YFP-tagged Myg1 protein in cell culture. The analysis of available EST, cDNA and genomic DNA sequences revealed that Myg1 4Gln allele is remarkably present in human populations but is never detected in homozygous state according to the HapMap database.</p> <p>Conclusions</p> <p>Our study demonstrated that both <it>MYG1 </it>promoter polymorphism -119C/G and Arg4Gln polymorphism in the mitochondrial signal of Myg1 have a functional impact on the regulation of the <it>MYG1 </it>gene and promoter polymorphism (-119C/G) is related with suspectibility for actively progressing vitiligo.</p
Highly specific memory b cells generation after the 2nd dose of bnt162b2 vaccine compensate for the decline of serum antibodies and absence of mucosal iga
Specific memory B cells and antibodies are a reliable read-out of vaccine efficacy. We analysed these biomarkers after one and two doses of BNT162b2 vaccine. The second dose significantly increases the level of highly specific memory B cells and antibodies. Two months after the second dose, specific antibody levels decline, but highly specific memory B cells continue to increase, thus predicting a sustained protection from COVID-19. We show that although mucosal IgA is not induced by the vaccination, memory B cells migrate in response to inflammation and secrete IgA at mucosal sites. We show that the first vaccine dose may lead to an insufficient number of highly specific memory B cells and low concentration of serum antibodies, thus leaving vaccinees without the immune robustness needed to ensure viral elimination and herd immunity. We also clarify that the reduction of serum antibodies does not diminish the force and duration of the immune protection induced by vaccination. The vaccine does not induce sterilizing immunity. Infection after vaccination may be caused by the lack of local preventive immunity because of the absence of mucosal IgA