RESUMO
Up-conversion phosphors have attracted considerable attention because of their applications in solid-state lasers, optical communications, flat-panel displays, photovoltaic cells, and biological labels. Among them, NaYF4 is reported as one of the most efficient hosts for infrared to visible photon up-conversion of Yb3+ and Er3+ ions. However, a low-temperature method is required for industrial scale fabrication of photonic and optoelectronic devices on flexible organic substrates. In this study, hexagonal ß-NaYF4: 3 mol% Yb3+, 3 mol% Er3+ up-conversion phosphor using Ca2+ was prepared by chemical solution method. Then, we synthesized a nanostructured organo-silicon compound from methyl tri-methoxysilane and 3-glycidoxy-propyl-trimethoxy-silane. The transmittance of the organo-silicon compound was found to be over 90% in the wavelength range of 400~1500 nm. Then we prepared a fluoride-based phosphor paste by mixing the organo-silicon compound with Na(Ca)YF4:Yb3+, Er3+. Subsequently, this paste was coated on polyethylene terephthalate, followed by heat-treatment at 120 °C. The visible emission of the infrared detection card was found to be at 655 nm and 661 nm an excitation wavelength of 980 nm.
RESUMO
Corn, one of the most important forage crops worldwide, has proven to be a useful expression vehicle due to the availability of established transformation procedures for this well-studied plant. The exotoxin Apx, a major virulence factor, is recognized as a common antigen of Actinobacillus (A.) pleuropneumoniae, the causative agent of porcine pleuropneumonia. In this study, a cholera toxin B (CTB)-ApxIIA#5 fusion protein and full-size ApxIIA expressed in corn seed, as a subunit vaccine candidate, were observed to induce Apx-specific immune responses in mice. These results suggest that transgenic corn-derived ApxIIA and CTB-ApxIIA#5 proteins are potential vaccine candidates against A. pleuropneumoniae infection.