Synthesis, structure and luminescence properties of bifunctional KCaF3 phosphor influenced by incorporating Eu3+ ions for solid state lighting and TL dosimetry applications.

Europium doped KCaF3 phosphors (KCaF3:Eu3+) were prepared using various concentrations of Eu3+ by conventional solid-state reaction process. The X-ray diffraction (XRD) studies confirmed the formation of orthorhombic structured KCaF3:Eu3+ phosphors. Scanning Electron Microscopy (SEM) image of the synthesized phosphor exhibits agglomerated particles with irregular shapes. The composition of the synthesized sample was determined by Energy Dispersive Spectroscopy (EDS) spectrum and elemental mapping showed the homogeneous dispersion of Eu3+ ions into the synthesized KCaF3:Eu3+ phosphor. The emission peak intensity at 594 nm from photoluminescence (PL) spectra was found to increase with the increase of Eu3+ concentrations from 0.02 mol% to 0.06 mol% and decreased with the further increase of Eu3+ concentration up to 0.1 mol%. CIE1931 chromaticity diagram coordinates (x, y) of KCaF3:(0.06 mol%) Eu3+ phosphors were positioned in the reddish-orange region (x = 0.5736, y = 0.4224). Photoluminescence property confirms the suitability of KCaF3:Eu3+ phosphors for Solid state lighting application. X-ray induced luminescence (radioluminescence, RL) is recorded for KCaF3:Eu3+ phosphors showing the characteristic emission of Eu2+ and Eu3+. ESR study on KCaF3:Eu3+ phosphors confirm the presence of Eu2+ ions. Beta irradiated thermoluminescence (TL) glow curve of Eu3+ doped KCaF3 phosphors is measured and deconvoluted using Gaussian fitting. TL kinetic parameters like activation energy (Ea) and frequency factor (s) are calculated for all the deconvoluted peaks using peak shape method which shows the synthesized KCaF3:Eu3+ phosphors is suitable for dosimetry application.

Insulin Signaling Augments eIF4E-Dependent Nonsense-Mediated mRNA Decay in Mammalian Cells.

Nonsense-mediated mRNA decay (NMD) modulates the level of mRNA harboring a premature termination codon (PTC) in a translation-dependent manner. Inhibition of translation is known to impair NMD; however, few studies have investigated the correlation between enhanced translation and increased NMD. Here, we demonstrate that insulin signaling events increase translation, leading to an increase in NMD of eIF4E-bound transcripts. We provide evidence that (i) insulin-mediated enhancement of translation augments NMD and rapamycin abrogates this enhancement; (ii) an increase in AKT phosphorylation due to inhibition of PTEN facilitates NMD; (iii) insulin stimulation increases the binding of up-frameshift factor 1 (UPF1), most likely to eIF4E-bound PTC-containing transcripts; and (iv) insulin stimulation induces the colocalization of UPF1 and eIF4E in processing bodies. These results illustrate how extracellular signaling promotes the removal of eIF4E-bound NMD targets.

Unidirectional growth of 〈001〉 triglycine zinc chloride crystal by Sankaranarayanan-Ramasamy (SR) method and its characterization.

Bulk nonlinear optical single crystal of triglycine zinc chloride (TGZC) of size 15mm diameter and 50mm length was successfully grown from solution by unidirectional growth method of Sankaranarayanan-Ramasamy (SR). The growth conditions were optimized and a maximum growth rate of 1.5mm per day was realized. The crystal system and lattice parameters were confirmed by powder X-ray diffraction studies. The structural perfection of the SR method grown crystal has been analyzed by high resolution X-ray diffraction measurement. The UV-Vis-NIR studies show that the cutoff wavelength is around 240nm. The dielectric measurements were carried out to determine the dielectric behavior for the crystal. The observations are made in the frequency range 1kHz-2MHz at the temperature range of 43-150°C. The fluorescence spectra of grown TGZC single crystals exhibit emission peak at 485nm. The microhardness measurements were used to analyze the mechanical strength of the grown TGZC crystal. The SHG efficiency of TGZC was confirmed by Kurtz-Perry powder method.