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In this paper, magnetic Fe 3 O 4 hollow spheres based magnetic-fluorescent nanoparticles, hollow structured Fe 3 O 4 @Gd 2 O 3 :Eu 3+ , were synthesized through a homogeneous precipitation method. The microstructure, luminescence, and magnetic properties of the samples were investigated and discussed with the help of various analytic techniques including X-ray diffraction, scanning electron microscope, energy dispersive spectrometer, cathodelumincence mapping, photoluminescence spectra and vibrating sample magnetometer. The hollow spheres nanoparticles, emitting at 612 nm dominantly under the 254 nm excitation, exhibited the photoluminescence intensity 2.45 times higher than the solid sphere samples, due to the. hollow spheres structure. The hollow Fe 3 O 4 @Gd 2 O 3 :Eu 3+ nanoparticles were spherical, and had a particle size of about 1400 nm in diameter. They also showed a saturation magnetization of 1.33 emu/g, a coercivity Hc of 160 Oe and a remanence of 0.05 emu/g at room temperature, the saturation magnetization of hollow spheres nanoparticles is higher than the solid sphere samples. The enhanced photoluminescence and magnetic properties of the hollow structured nanoparticles allow them to be used in biomedical applications.

In this paper, the Gd 3+ codoped bifunctional coreshell nanoparticles, Fe 3 O 4 @(Y 1-x Gd x ) 2 O 3 :Eu 3+ , were synthesized through a Urea Homogeneous Preci-pitation method. The microstructure, luminescence, and magnetic properties of the codoped samples were investigated and discussed with the help of various analytic techniques including X-ray diffraction, scanning electron microscope, photo-luminescence spectra, cathodelumincence mapping and vibrating sample magnetometer. The co-doped sample (x = 0.3), emitting at 612 nm dominantly under the 254 nm excitation, exhibited the photoluminescence intensity 2.7 times higher than the undoped one (x = 0), due to the efficient energy transfer between Gd 3+ and Eu 3+ . The Fe 3 O 4 @(Y 1-x Gd x ) 2 O 3 :Eu 3+ core–shell nanoparticles were spherical and uniform, and had a particle size of about 180 nm in diameter. They also showed a saturation magnetization of 1.09 emu/g, a coercivity of 20 Oe and a remanence of 0.01emu/g. The enhanced photoluminescence and good magnetic properties of the title core–shell nanocomposites allow them to be used in biomedical applications.

In this paper, bifunctional Fe 3 O 4 @Gd 2 O 3 :Eu 3+ core-shell nanoparticles with both magnetic and fluorescent properties were synthesized through a urea homogeneous precipitation (UHP) method. Particular emphasis was placed on investigating the influence of the solution pH value on the photoluminescence of the core-shell nanocomposites. It showed that the samples treated at the solution of pH=3.0 had the highest luminescence due to the enhanced crystallinity and size uniformity of nanoparticles. The Fe 3 O 4 @Gd 2 O 3 :Eu 3+ nanocomposites exhibited an almost spherical shape with a mean diameter of 60 nm, and had strong red emissions of Eu 3+ at 612 nm as well as good magnetization with the saturation magnetization of 1.29 emu/g. It thus indicated that the core-shell nanocomposites investigated has great potential in biomedical applications.

Keywords: Oxynitride phosphor; Precursor method; White LEDs; Photoluminescence Abstract. Bluish-green BaSi2O2N2:Eu 2+ phosphors were synthesized by a method using Ba2SiO4 as a precursor. The luminescence properties and formation process of BaSi2O2N2:Eu 2+ phosphors formed by the method at varied Eu 2+ concentrations and varied temperatures were investigated by X-ray diffraction (XRD), fluorescence spectrometer photometer (PL) and scanning electron microscope (SEM) respectively. Compared with a conventional solid-state reaction method, this method provided increased crystallinity and luminescence efficiency. A single phase of BaSi2O2N2:Eu 2+ was formed in the precursor method. Under 330 nm excitation, the BaSi2O2N2:Eu 2+ phosphors showed a broad emission band with a peak of 498 nm for varied Eu 2+ concentrations and showed the maximum emission peak intensity when Eu 2+ doping amount was 4%. These excellent luminescence properties suggested that BaSi2O2N2:Eu 2+ is an excellent phosphor for white LEDs.

Bluish-green Ba 3 Si 6 O 9 N 4 :Eu2+ phosphors were synthesized by two-step synthesis processes using BaSiO 3 as a precursor. The samples were prepared by high-temperature solid-state reaction, and investigated by X-ray diffraction (XRD) and fluorescence spectrometer photometer (PL) respec-tively. The results of XRD illustrated that two-step method was beneficial to improve phases of Ba 3 Si 6 O 9 N 4 :Eu2+ phosphor and obtain higher crystallinity. The maximum luminescent intensi-ty of two-step process and high temperature solid-state method was obtained, when Eu2+ doping amount was 9%. After calcul-ation, the distance of quenching was determined at 18.71 Ǻ. Compared the emission spectrum of two-step process(the emission peak at 498 nm) with high-temperature solid phase method (the emission peak at 517 nm) under the excitation of 330 nm, an apparent electrophoresis of the blue shift was existed. And the emission peak of two-step process was closer to the value of theoretical (480nm). The results of energy spectrum analysis clarified that the elements content of two-step method was closer to the theoretical stoichiometry ratio, which indicated that two-step preparation of Ba 3 Si 6 O 9 N 4 :Eu2+ phosphor was an effective way to reduce the lattice defects.

Magnetic–luminescent nanoparticles are now attracting great attention in biochemistry and biomedicine for their promising bifunctional characteristics. In this work, we propose a strategy of Li+ doping to enhance both the luminescent and magnetic properties of Fe3O4@Y2O3:Eu3+ core–shell particles. A comprehensive investigation of phase assembly, microscopic morphology, luminescence, and magnetic characteristics of the bifunctional particles was carried out. The core–shell structured particles have a spherical morphology and the agglomerated particle size is ~1 μm in diameter. Under 254 nm excitation, the co-doped sample (5 mol-% Li+) with a dominant emission peak at 612 nm, exhibits luminescence 2.35 times more intense than the undoped sample (0 mol-% Li+). Li+ doping also leads to an improved saturation magnetisation, which was 2.41 times greater than the undoped sample.

Background/Aims: SPAK (STE20-related proline/alanine-rich kinase) is a powerful regulator of renal tubular ion transport and blood pressure. Moreover, SPAK contributes to the regulation of cell volume. Little is known, however, about a role of SPAK in the regulation or organic solutes. The present study thus addressed the influence of SPAK on the peptide transporters PEPT1 and PEPT2. Methods: To this end, cRNA encoding PEPT1 or PEPT2 were injected into Xenopus laevis oocytes without or with additional injection of cRNA encoding wild-type, SPAK, WNK1 insensitive inactive T233ASPAK, constitutively active T233ESPAK, and catalytically inactive D212ASPAK. Electrogenic peptide (glycine-glycine) transport was determined by dual electrode voltage clamp and PEPT2 protein abundance in the cell membrane by chemiluminescence. Intestinal electrogenic peptide transport was estimated from peptide induced current in Ussing chamber experiments of jejunal segments isolated from gene targeted mice expressing SPAK resistant to WNK-dependent activation (spaktg/tg) and respective wild-type mice (spak+/+). Results: In PEPT1 and in PEPT2 expressing oocytes, but not in oocytes injected with water, the dipeptide gly-gly (2 mM) generated an inward current, which was significantly decreased following coexpression of SPAK. The effect of SPAK on PEPT1 was mimicked by T233ESPAK, but not by D212ASPAK or T233ASPAK. SPAK decreased maximal peptide induced current of PEPT1. Moreover, SPAK decreased carrier protein abundance in the cell membrane of PEPT2 expressing oocytes. In intestinal segments gly-gly generated a current, which was significantly higher in spaktg/tg than in spak+/+ mice. Conclusion: SPAK is a powerful regulator of peptide transporters PEPT1 and PEPT2.

Color rendition, luminous efficacy and reliability are three key technical parameters for white light-emitting diodes (wLEDs) that are dominantly determined by down-conversion phosphors. However, there is usually an inevitable trade-off between color rendition and luminescence efficacy because the spectrum of red phosphor (that is, spectral broadness and position) cannot satisfy them simultaneously. In this work, we report a very promising red phosphor that can minimize the aforementioned trade-off via structure and band-gap engineering, achieved by introducing isostructural LiSi2N3 into CaAlSiN3:Eu2+. The solid solution phosphors show both substantial spectra broadening (88→117 nm) and blueshift (652→642 nm), along with a significant improvement in thermal quenching (only a 6% reduction at 150 °C), which are strongly associated with electronic and crystal structure evolutions. The broadband and robust red phosphor thus enables fabrication of super-high color rendering wLEDs (Ra=95 and R9=96) concurrently with the maintenance of a high-luminous efficacy (101 lm W−1), validating its superiority in high-performance solid state lightings over currently used red phosphors. A new red phosphor with broadband emission has yielded white LEDs that have both a high luminous efficacy and excellent colour rendering. By applying structure and bandgap engineering strategies, Rong-Jun Xie and co-workers from China, Japan and the USA fabricated their rare-earth phosphor from Ca1−xLixAl1−xSi1+xN3:Eu2+. They say that the introduction of LiS2N3 to CaAlSiN3:Eu2+ minimizes the usual trade-off between emission colour and efficiency. When the red phosphor was combined with a commercial blue InGaN LED and a green phosphor, the result was a white LED with a luminous efficacy exceeding 100 lumens per watt and a high colour rendering. The researchers note that in addition to superior colour quality, the use of LiS2N3 imparts better thermal stability to the phosphor compared with currently used red phosphors.