486 research outputs found
Editorial: state-of-the-art fluorescence image-guided surgery: current and future developments
Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
The environment effect on operation of in-vessel mirrors for plasma diagnostics in fusion devices
First mirrors will be the plasma facing components of optical diagnostic
systems in ITER. Mirror surfaces will undergo modification caused by erosion
and re-deposition processes [1,2]. As a consequence, the mirror performance may
be changed and may deteriorate [3,4]. In the divertor region it may also be
obscured by deposition [5-7]. The limited access to in-vessel components of
ITER calls for testing the mirror materials in present day devices in order to
gather information on the material damage and degradation of the mirror
performance, i.e. reflectivity. A dedicated experimental programme, First
Mirror Test (FMT), has been initiated at the JET tokamak within the framework
Tritium Retention Studies (TRS).Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France).Submitted by B. Schunke on behalf of V. Voytseny
Effect of the low energy ion bombardment on the optical properties of metallic mirrors
Schemes of several methods of plasma diagnostics in ITER in a high degree must be based on utilization of the reflective optics. In this connection there appeared the problem of the first mirrors (FM), i.e., mirrors directed to plasma under investigation. The FMs will be subjected to bombardment by charge exchange atoms (CXA) and to deposition of contaminating materials. The CXA energy distribution will be very different for different mirrors, namely, it will be much higher with long tail in the case of mirrors for the core plasma than for mirrors in the divertor region. In this paper we present some results of investigations of effect of the long-term bombardment by deuterium ions with sub- or near-threshold energy on reflectance of metallic mirrors
Grain size-dependent magnetic and electric properties in nanosized YMnO3 multiferroic ceramics
Magnetic and electric properties are investigated for the nanosized YMnO3 samples with different grain sizes (25 nm to 200 nm) synthesized by a modified Pechini method. It shows that magnetic and electric properties are strongly dependent on the grain size. The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 52 to 74 K. A corresponding shift of the dielectric anomaly is observed, indicating a strong correlation between the electric polarization and the magnetic ordering. Further analysis suggests that the rising of AFM transition temperature with increasing grain size should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters. Furthermore, among all samples, the sample with grain size of 95 nm is found to have the smallest leakage current density (< 1 μA/cm2)
Hypersensitive Response-Like Reaction Is Associated with Hybrid Necrosis in Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii Coss
BACKGROUND: Hybrid speciation is classified into homoploid and polyploid based on ploidy level. Common wheat is an allohexaploid species that originated from a naturally occurring interploidy cross between tetraploid wheat and diploid wild wheat Aegilops tauschii Coss. Aegilops tauschii provides wide naturally occurring genetic variation. Sometimes its triploid hybrids with tetraploid wheat show the following four types of hybrid growth abnormalities: types II and III hybrid necrosis, hybrid chlorosis, and severe growth abortion. The growth abnormalities in the triploid hybrids could act as postzygotic hybridization barriers to prevent formation of hexaploid wheat. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report on the geographical and phylogenetic distribution of Ae. tauschii accessions inducing the hybrid growth abnormalities and showed that they are widely distributed across growth habitats in Ae. tauschii. Molecular and cytological characterization of the type III necrosis phenotype was performed. The hybrid abnormality causing accessions were widely distributed across growth habitats in Ae. tauschii. Transcriptome analysis showed that a number of defense-related genes such as pathogenesis-related genes were highly up-regulated in the type III necrosis lines. Transmission electron microscope observation revealed that cell death occurred accompanied by generation of reactive oxygen species in leaves undergoing type III necrosis. The reduction of photosynthetic activity occurred prior to the appearance of necrotic symptoms on the leaves exhibiting hybrid necrosis. CONCLUSIONS/SIGNIFICANCE: Taking these results together strongly suggests that an autoimmune response might be triggered by intergenomic incompatibility between the tetraploid wheat and Ae. tauschii genomes in type III necrosis, and that genetically programmed cell death could be regarded as a hypersensitive response-like cell death similar to that observed in Arabidopsis intraspecific and Nicotiana interspecific hybrids. Only Ae. tauschii accessions without such inhibiting factors could be candidates for the D-genome donor for the present hexaploid wheat
Global gene expression analysis of the mouse colonic mucosa treated with azoxymethane and dextran sodium sulfate
<p>Abstract</p> <p>Background</p> <p>Chronic inflammation is well known to be a risk factor for colon cancer. Previously we established a novel mouse model of inflammation-related colon carcinogenesis, which is useful to examine the involvement of inflammation in colon carcinogenesis. To shed light on the alterations in global gene expression in the background of inflammation-related colon cancer and gain further insights into the molecular mechanisms underlying inflammation-related colon carcinogenesis, we conducted a comprehensive DNA microarray analysis using our model.</p> <p>Methods</p> <p>Male ICR mice were given a single ip injection of azoxymethane (AOM, 10 mg/kg body weight), followed by the addition of 2% (w/v) dextran sodium sulfate (DSS) to their drinking water for 7 days, starting 1 week after the AOM injection. We performed DNA microarray analysis (Affymetrix GeneChip) on non-tumorous mucosa obtained from mice that received AOM/DSS, AOM alone, and DSS alone, and untreated mice at wks 5 and 10.</p> <p>Results</p> <p>Markedly up-regulated genes in the colonic mucosa given AOM/DSS at wk 5 or 10 included Wnt inhibitory factor 1 (<it>Wif1</it>, 48.5-fold increase at wk 5 and 5.7-fold increase at wk 10) and plasminogen activator, tissue (<it>Plat</it>, 48.5-fold increase at wk 5), myelocytomatosis oncogene (<it>Myc</it>, 3.0-fold increase at wk 5), and phospholipase A2, group IIA (platelets, synovial fluid) (<it>Plscr2</it>, 8.0-fold increase at wk 10). The notable down-regulated genes in the colonic mucosa of mice treated with AOM/DSS were the peroxisome proliferator activated receptor binding protein (<it>Pparbp</it>, 0.06-fold decrease at wk 10) and the transforming growth factor, beta 3 (<it>Tgfb3</it>, 0.14-fold decrease at wk 10). The inflammation-related gene, peroxisome proliferator activated receptor γ (<it>Pparγ </it>0.38-fold decrease at wk 5), was also down-regulated in the colonic mucosa of mice that received AOM/DSS.</p> <p>Conclusion</p> <p>This is the first report describing global gene expression analysis of an AOM/DSS-induced mouse colon carcinogenesis model, and our findings provide new insights into the mechanisms of inflammation-related colon carcinogenesis and the establishment of novel therapies and preventative strategies against carcinogenesis.</p
- …