Tailoring the microstructure of Mn-Zn ferrite to electronic properties

Commercial Mn-Zn ferrite powder was milled in a planetary ball mill for 30-240 minutes. Particle size distribution in the milled powders was analyzed using a laser particle size analyzer and correlated with XRD and SEM analysis of the milled powders. Green disc and torroid samples were sintered in air in the temperature interval 800 -1300oC for 2 hours. SEM/EDS, AFM/MFM analysis of the sintered samples and measurements of their electrical properties such as DC resistance up to 500 MHz enabled establishment of a correlation between the microstructure and properties in the high-frequency range

Tailoring the microstructure of Mn-Zn ferrite to electronic properties

Commercial Mn-Zn ferrite powder was milled in a planetary ball mill for 30-240 minutes. Particle size distribution in the milled powders was analyzed using a laser particle size analyzer and correlated with XRD and SEM analysis of the milled powders. Green disc and torroid samples were sintered in air in the temperature interval 800 -1300oC for 2 hours. SEM/EDS, AFM/MFM analysis of the sintered samples and measurements of their electrical properties such as DC resistance up to 500 MHz enabled establishment of a correlation between the microstructure and properties in the high-frequency range

Neratinib protects pancreatic beta cells in diabetes

The loss of functional insulin-producing β-cells is a hallmark of diabetes. Mammalian sterile 20-like kinase 1 (MST1) is a key regulator of pancreatic β-cell death and dysfunction; its deficiency restores functional β-cells and normoglycemia. The identification of MST1 inhibitors represents a promising approach for a β-cell-protective diabetes therapy. Here, we identify neratinib, an FDA-approved drug targeting HER2/EGFR dual kinases, as a potent MST1 inhibitor, which improves β-cell survival under multiple diabetogenic conditions in human islets and INS-1E cells. In a pre-clinical study, neratinib attenuates hyperglycemia and improves β-cell function, survival and β-cell mass in type 1 (streptozotocin) and type 2 (obese Leprdb/db) diabetic mouse models. In summary, neratinib is a previously unrecognized inhibitor of MST1 and represents a potential β-cell-protective drug with proof-of-concept in vitro in human islets and in vivo in rodent models of both type 1 and type 2 diabetes

Solid-state reference electrodes based on carbon nanotubes and polyacrylate membranes

A novel potentiometric solid-state reference electrode containing single-walled carbon nanotubes as the transducer layer between a polyacrylate membrane and the conductor is reported here. Single-walled carbon nanotubes act as an efficient transducer of the constant potentiometric signal originating from the reference membrane containing the Ag/AgCl/Cl− ions system, and they are needed to obtain a stable reference potentiometric signal. Furthermore, we have taken advantage of the light insensitivity of single-walled carbon nanotubes to improve the analytical performance characteristics of previously reported solid-state reference electrodes. Four different polyacrylate polymers have been selected in order to identify the most efficient reservoir for the Ag/AgCl system. Finally, two different arrangements have been assessed: (1) a solid-state reference electrode using photo-polymerised n-butyl acrylate polymer and (2) a thermo-polymerised methyl methacrylate:n-butyl acrylate (1:10) polymer. The sensitivity to various salts, pH and light, as well as time of response and stability, has been tested: the best results were obtained using single-walled carbon nanotubes and photo-polymerised n-butyl acrylate polymer. Water transport plays an important role in the potentiometric performance of acrylate membranes, so a new screening test method has been developed to qualitatively assess the difference in water percolation between the polyacrylic membranes studied. The results presented here open the way for the true miniaturisation of potentiometric systems using the excellent properties of single-walled carbon nanotubes