Molecular Beam Epitaxy of Wurtzite (Ga,Mn)N Films on Sapphire(0001) Showing the Ferromagnetic Behaviour at Room Temperature

Wurtzite (Ga,Mn)N films showing ferromagnetic behaviour at room temperature were successfully grown on sapphire(0001) substrates by molecular beam epitaxy using ammonia as nitrogen source. Magnetization measurements were carried out by a superconducting quantum interference device at the temperatures between 1.8K and 300K with magnetic field applied parallel to the film plane up to 7T. The magnetic-field dependence of magnetization of a (Ga,Mn)N film at 300K were ferromagnetic, while a GaN film showed Pauli paramagnetism like behaviour. The Curie temperatures of a (Ga,Mn)N film was estimated as 940K.Comment: 5 page

High TC ferromagnetism in diluted magnetic semiconducting GaN:Mn films

Wurtzite GaN:Mn films on sapphire substrates were successfully grown by use of the molecular beam epitaxy (MBE) system. The film has an extremely high Curie temperature of around 940 K, although the Mn concentration is only about 3 ~ 5 %. Magnetization measurements were carried out in magnetic fields parallel to the film surface up to 7 T. The magnetization process shows the coexistence of ferromagnetic and paramagnetic contributions at low temperatures, while the typical ferromagnetic magnetization process is mainly observed at high temperatures because of the decrease of the paramagnetic contributions. The observed transport characteristics show a close relation between the magnetism and the impurity conduction. The double exchange mechanism of the Mn-impurity band is one of the possible models for the high-TC ferromagnetism in GaN:Mn.Comment: 20 pages, 4 figures, submitted to Physica

The role of Cysteine 227 in subcellular localization, water permeability, and multimerization of aquaporin-11

Aquaporin-11 (AQP11) is the latest member of the mammalian water channel protein family to be described. Recent in vivo studies have shown that mutation at Cys227 causes renal failure. However the importance of Cys227 for the molecular function of AQP11 is largely unknown. In this study, we examined the subcellular localization, water permeability, and multimerization of AQP11 with a mutation at Cys227. Interestingly, cells expressing the mutants had significantly higher osmotic water permeability. In contrast, the mutation lowered the cell surface expression and multimerization levels. Our observations suggest that Cys227 is crucial for the proper molecular function of AQP11

Beneficial effects of tonsillectomy plus steroid pulse therapy on inflammatory and tubular markers in patients with IgA nephropathy

Background: IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide. Tonsillectomy plus steroid pulse therapy has been able to induce clinical remission in early-stage IgAN. However, its possible effect on systemic and local cytokines and tubular markers has not been fully investigated. Methods: We obtained serum and urine samples from 38 patients just before renal biopsy and third steroid pulse therapy. Markers of tubular damage such as N-acetyl-β-d-glucosaminidase, and kidney injury molecule-1 and inflammation such as interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 were measured by immunoassay. Results: Before renal biopsy, only urinary inflammatory markers, except MCP-1, were associated with glomerular (proteinuria) and/or tubular damage markers. Proteinuria, hematuria, and estimated glomerular filtration rate dramatically improved after therapy. In addition, levels of serum IL-6 and ICAM-1 and all urinary markers declined significantly; however, serum MCP-1 and VCAM-1 levels did not. None of the urinary markers correlated with the serum inflammatory markers. Conclusion: Tonsillectomy plus steroid pulse therapy for patients with IgAN might be useful for improving not only glomerular damage marker but also tubular damage markers through the improvement of local renal inflammation

Atractylodin Produces Antinociceptive Effect through a Long-Lasting TRPA1 Channel Activation

Atractylodin (ATR) is a bioactive component found in dried rhizomes of Atractylodes lancea (AL) De Candolle. Although AL has accumulated empirical evidence for the treatment of pain, the molecular mechanism underlying the anti-pain effect of ATR remains unclear. In this study, we found that ATR increases transient receptor potential ankyrin-1 (TRPA1) single-channel activity in hTRPA1 expressing HEK293 cells. A bath application of ATR produced a long-lasting calcium response, and the response was completely diminished in the dorsal root ganglion neurons of TRPA1 knockout mice. Intraplantar injection of ATR evoked moderate and prolonged nociceptive behavior compared to the injection of allyl isothiocyanate (AITC). Systemic application of ATR inhibited AITC-induced nociceptive responses in a dose-dependent manner. Co-application of ATR and QX-314 increased the noxious heat threshold compared with AITC in vivo. Collectively, we concluded that ATR is a unique agonist of TRPA1 channels, which produces long-lasting channel activation. Our results indicated ATR-mediated anti-nociceptive effect through the desensitization of TRPA1-expressing nociceptors