Magnetic and Electrical Properties of Ordered 112-type Perovskite LnBaCoMnO5+\delta (Ln = Nd, Eu)

Investigation of the oxygen-deficient 112-type ordered oxides of the type LnBaCoMnO5+\delta (Ln = Nd, Eu) evidences certain unusual magnetic behavior at low temperatures, compared to the LnBaCo2O5+\delta cobaltites. One observes that the substitution of manganese for cobalt suppresses the ferromagnetic state and induces strong antiferromagnetic interactions. Importantly, NdBaCoMnO5.9 depicts a clear paramagnetic to antiferromagnetic type transition around 220 K, whereas for EuBaCoMnO5.7 one observes an unusual magnetic behavior below 177 K which consists of ferromagnetic regions embedded in an antiferromagnetic matrix. The existence of two sorts of crystallographic sites for Co/Mn and their mixed valence states favor the ferromagnetic interaction whereas antiferromagnetism originates from the Co3+-O-Co3+ and Mn4+-O-Mn4+ interactions. Unlike the parent compounds, the present Mn-substituted phases do not exhibit prominent magnetoresistance effects in the temperature range 75-400K.Comment: 23 pages including figure

Alcohol consumption and risk of microvascular complications in type 1 diabetes patients: The EURODIAB Prospective Complications Study

Aims/hypothesis: The aim of this study was to investigate the association between alcohol consumption and risk of microvascular complications (retinopathy, neuropathy, nephropathy) in type 1 diabetes mellitus patients in the EURODIAB Prospective Complications Study. Methods: The EURODIAB Prospective Complications Study is a follow-up study including 3,250 type 1 diabetes mellitus patients from 16 different European countries. Results: We investigated the cross-sectional association between moderate alcohol consumption and risk of retinopathy, neuropathy and nephropathy among 1,857of these patients. We documented 304 cases of proliferative retinopathy, 660 cases of neuropathy and 157 cases of nephropathy (macroalbuminuria). Alcohol consumption was associated with risk of proliferative retinopathy, neuropathy and macroalbuminuria in a U-shaped fashion. Moderate consumers (30-70 g alcohol per week) had a lower risk of microvascular complications with odds ratios of 0.60 (95% CI 0.37-0.99) for proliferative retinopathy, 0.61 (0.41-0.91) for neuropathy and 0.36 (0.18-0.71) for macroalbuminuria in multivariate-adjusted models. These results were similar when excluding patients who had been advised to drink less alcohol because of their health. The relation was most pronounced for alcohol consumption from wine. Drinking frequency was significantly, inversely associated with risk of neuropathy, but a similar trend was visible for proliferative retinopathy and macroalbuminuria. Alcohol consumption was not associated with occurrence of ketoacidosis or hypoglycaemic attacks. Conclusions/interpretation: Consistent with its effects on macrovascular complications, moderate alcohol consumption is associated with a lower risk of all microvascular complications among type 1 diabetes patients

Enhancing the Oxygen Permeation Rate of Zr0.84Y0.16O1.92 - La0.8Sr0.2Cr0.5Fe0.5O3-δ Dual-Phase Hollow Fiber Membrane by Coating with Ce0.8Sm0.2O1.9 Nanoparticles

Zr0.84Y0.16O1.92−La0.8Sr0.2Cr0.5Fe0.5O3−δ (YSZ-LSCrF) dual-phase composite hollow fiber membranes were prepared by a combined phase-inversion and sintering method. The shell surface of the hollow fiber membrane was modified with Ce0.8Sm0.2O1.9 (SDC) via a drop−coating method. As the rate of oxygen permeation of the unmodified membrane is partly controlled by the surface exchange kinetics, coating of a porous layer of SDC on the shell side (oxygen reduction side) of the hollow fiber membrane was found to improve its oxygen permeability. Rate enhancements up to 113 and 48% were observed, yielding a maximum oxygen flux of 0.32 and 4.53 mL min−1 cm−2 under air/helium and air/CO gradients at 950 °C, respectively. Excess coating of SDC was found to induce significant gas phase transport limitations and hence lower the rate of oxygen permeation. A model was proposed to calculate the length of triple phase boundaries (TPBs) for the coated dual-phase composite membrane and to explain the effect of coating on the oxygen permeability