Highly efficient phosphor-converted white organic light-emitting diodes with moderate microcavity and light-recycling filters.

We demonstrate the combined effects of a microcavity structure and light-recycling filters (LRFs) on the forward electrical efficiency of phosphor-converted white organic light-emitting diodes (pc-WOLEDs). The introduction of a single pair of low- and high-index layers (SiO(2)/TiO(2)) improves the blue emission from blue OLED and the insertion of blue-passing and yellow-reflecting LRFs enhances the forward yellow emission from the YAG:Ce(3+) phosphors layers. The enhancement of the luminous efficacy of the forward white emission is 1.92 times that of a conventional pc-WOLED with color coordinates of (0.34, 0.34) and a correlated color temperature of about 4800 K.

Emergence of vanA Genotype Vancomycin-Resistant Enterococci with Low or Moderate Levels of Teicoplanin Resistance in Korea.

In Korea, vancomycin-resistant enterococci have become important nosocomial pathogens since the late 1990s, and most vancomycin-resistant enterococcal isolates have been VanA phenotype-vanA genotype strains. In 2001, we experienced an outbreak of VanB phenotype-vanA genotype vancomycin-resistant enterococci at a university hospital. This is the first report of VanB-vanA vancomycin-resistant enterococci from humans in Korea.