179 research outputs found

    Large Magnetoresistance Effects in LnLnCoAsO with a Ferromagnetic-Antiferromagnetic Transition

    Full text link
    A large magnetoresistance (MR) effect was observed in the layered compounds NdCoAsO and SmCoAsO, in which ferromagnetically ordered itinerant-electrons of Co are sandwiched by localized 4ff-electrons of Ln3+Ln^{3+}, below ferromagnetic-antiferromagnetic transition (FAFT) temperature TNT_\mathrm{N} as observed in other FAFT compounds. In SmCoAsO, the large MR effect is also observed up to the Curie temperature TCT_\mathrm{C}, and it is found to be originating in the presence of another antiferromagnetic phase in the low-magnetic field region of the ferromagnetic phase.Comment: 5 pages, 5 figure

    Effects of helical centerline stent vs. straight stent placement on blood flow velocity

    Get PDF
    As an approach to maintain patency in femoropopliteal stenting, a helical stent configuration was proposed, which showed improved patency in clinical trials. However, the effects of helical stent placement on the flow have not been quantitatively analyzed. The purpose of this study was to estimate flow velocities to quantify the influence of helical stent placement. Helical and straight stents were implanted in three healthy pigs, and the flow velocities were estimated using the time-intensity curve (TIC) in the angiography images. The angiographic images indicated thinning of the leading edge of the contrast medium through the helically deformed artery, which was not observed in the straight stent. The slower rise of the TIC peak in the helical stent indicated faster travel of this thinner edge. Arterial expansion due to stenting was observed in all cases, and the expansion rate varied according to location. All cases of helical stent implantation showed that velocity was maintained (55.0%–71.3% velocity retention), unlike for straight stent implantation (43.0%–68.0% velocity retention); however, no significant difference was observed

    Transmission of bacterial infections to healthcare workers during intubation and respiratory care of patients with severe pneumonia

    Get PDF
    Exposure of healthcare workers to patients with rapidly fatal infections invariably raises concerns regarding the risk of occupational acquisition. We describe acquisition of Streptococcus pyogenes by 2 nurses from a patient with fatal pneumonia and review previously reported cases of transmission of bacterial pathogens from patients with pneumonia to healthcare workers

    A pathway of neuregulin-induced activation of cofilin-phosphatase Slingshot and cofilin in lamellipodia

    Get PDF
    Cofilin mediates lamellipodium extension and polarized cell migration by stimulating actin filament dynamics at the leading edge of migrating cells. Cofilin is inactivated by phosphorylation at Ser-3 and reactivated by cofilin-phosphatase Slingshot-1L (SSH1L). Little is known of signaling mechanisms of cofilin activation and how this activation is spatially regulated. Here, we show that cofilin-phosphatase activity of SSH1L increases ∼10-fold by association with actin filaments, which indicates that actin assembly at the leading edge per se triggers local activation of SSH1L and thereby stimulates cofilin-mediated actin turnover in lamellipodia. We also provide evidence that 14-3-3 proteins inhibit SSH1L activity, dependent on the phosphorylation of Ser-937 and Ser-978 of SSH1L. Stimulation of cells with neuregulin-1β induced Ser-978 dephosphorylation, translocation of SSH1L onto F-actin–rich lamellipodia, and cofilin dephosphorylation. These findings suggest that SSH1L is locally activated by translocation to and association with F-actin in lamellipodia in response to neuregulin-1β and 14-3-3 proteins negatively regulate SSH1L activity by sequestering it in the cytoplasm
    corecore