“
“Polycrystalline La2/3Sr1/3MnO3 thin films were synthesized by pulsed laser ablation on single crystal (100) yttria-stabilized zirconia substrates to investigate the mechanism of magnetotransport in a granular manganite. Different degrees of granularity are achieved by using the deposition temperatures (T-D) of 700 and 800 degrees C. Although no significant change in magnetic order temperature (T-C) and saturation magnetization is seen for these two types of films, the temperature and magnetic field dependence of their LCL161 mouse resistivity (rho(T,H)) is strikingly dissimilar. While
the rho(T,H) of the 800 degrees C film is comparable to that of epitaxial samples, the lower growth temperature leads to a material which undergoes insulator-to-metal transition at a temperature (T-P approximate to 170 K) much lower than T-C. At T << T-P, the resistivity is characterized by a minimum followed by ln T divergence at still lower temperatures. The high negative magnetoresistance (approximate to 20%) and ln T dependence below the minimum are explained on the basis of Kondo-type scattering from blocked Mn spins in the intergranular material.
Further, a striking feature of the T-D = 700 degrees C film is its two orders of magnitude larger anisotropic magnetoresistance (AMR) as compared to the AMR of epitaxial films. We attribute it to unquenching of the orbital angular momentum of 3d electrons of Mn ions in the intergranular region where crystal field is poorly defined. (C) selleck inhibitor see more 2009 American Institute of Physics. [DOI: 10.1063/1.3124372]“
“Objectives: Studies regarding the clinical features and outcomes of pediatric lupus nephritis are limited, and risk factors of poor outcome in the more severe form of renal involvement, proliferative lupus nephritis (PLN), are poorly understood. This study analyzed the data from a large prospective cohort of childhood systemic lupus erythematosus to determine such risk factors.
Methods: Subjects younger than 18 years at onset with biopsy-proven lupus nephritis were enrolled. Data on baseline presentations and laboratory values, response to treatment, and outcomes were collected. Primary outcome measures were death or end-stage
renal disease (ESRD). Survival analysis was done and predictors were approached.
Results: One hundred four patients with mean age of 12.4 +/- 2.5 years (range, 4.0-17.2 years) and the female-to-male ratio of 5.94:1 were included. Among them, 81 patients had PLN and 23 had non-proliferative lupus nephritis. Those with PLN had significantly lower GFR, more proteinuria, more urine sediment, more hypertension, and poor early response to treatment (within 6 months). There was no significant difference in extra-renal manifestations. All poor outcomes happened in the PLN group. The prognostic factors were high baseline SLEDAI-2k >20 (HR, 6.76; p = 0.002), baseline GFR <60 ml/min/m(2) (HR, 3.88; p = 0.022), and early responder (HR, 0.19; p = 0.013).