Efficient ultrapure green OLEDs were demonstrated by using a platinum complex (PtN7N) and a top emitting structure.

Chimeric mice with humanized livers are considered a useful animal model for predicting human (h-) drug metabolism and toxicity. In this study, the characteristics of fresh h-hepatocytes (cFHHs, PXB-cells ®) isolated from chimeric mice (PXB-mice ®) were evaluated in vitro to confirm their utility for drug development. cFHHs cultured at high density (2.13 × 10 5 cells/ cm 2) displayed stable production of h-albumin and cytochrome P450 (CYP) 3A activities for at least 21 days. The mRNA expression levels of 10 of 13 CYP, UDP-glucuronosyltransferase (UGT), and transporters were maintained at >10% of the levels of freshly isolated cFHHs after 21 days. From 1 week, many bile canaliculi were observed between cFHHs, and the accumulation of the multidrug resistance-associated protein and bile salt export pump substrates in these bile canaliculi was clearly inhibited by cyclosporin A. Microarray analysis of cFHHs cultured at high density and at low density (0.53 × 10 5 cells/cm 2) revealed that high density culture maintained high expressions of some transcription factors (HNF4α, PXR, and FXR) perhaps involved in the high CYP, UGT and transporter gene expressions of cFHHs. These results strongly suggest that cFHHs could be a novel in vitro tool for drug development studies.

Organic light-emitting diodes are a key technology for next-generation information displays because of their low power consumption and potentially long operational lifetimes. Although devices with internal quantum efficiencies of approximately 100% have been achieved using phosphorescent or thermally activated delayed fluorescent emitters, a systematic understanding of materials suitable for operationally stable devices is lacking. Here we demonstrate that the operational stability of phosphorescent devices is nearly proportional to the Förster resonance energy transfer rate from the host to the emitter when thermally activated delayed fluorescence molecules are used as the hosts. We find that a small molecular size is a requirement for thermally activated delayed fluorescence molecules employed as phosphorescent hosts; in contrast, an extremely small energy gap between the singlet and triplet excited states, which is essential for an efficient thermally activated delayed fluorescent emitter, is unnecessary in the phosphorescent host.

Long-term administration of hesperidin (HES) or glucosyl hesperidin (GHES), a water-soluble analogue of HES, brings about an antihypertensive effect on spontaneously hypertensive rats (SHR). In the present study, we investigated the effects of long-term admin istration of HES and GHES (corresponding to 30mg/d/kg body weight) on serum lipid con centration and morphology of vasculature. Serum HDL cholesterol increased in both SHR and Wistar-Kyoto rats (WKY) fed a HES-or GHES-containing diet for 25wk. Simulta neously, GHES administration reduced the vascular diameter and media-intimal cross-sec tional area of the abdominal aorta in SHR. These results suggest that HES as well as GHES improves serum cholesterol composition and that GHES inhibits hypertrophy in vasculature as well.

Quantum dots (QDs) are expected to be used as an emitting material in wide-color-gamut displays. However, the development of low-toxicity alternatives is necessary because QDs that exhibit high color purity and highly efficient emission contain toxic materials such as Cd. Here, QD light-emitting diodes (QD-LEDs) fabricated using AgInS2/GaSx core/shell QDs (AIS core/shell QDs) as low-toxicity QDs were investigated. The photoluminescence (PL) spectrum of an AIS core/shell QD dispersion showed a band edge emission with a peak wavelength of 560 nm and a full-width at half-maximum of 45 nm because the GaSx shell suppressed the surface defects. Electroluminescence (EL) emission, which mainly comprises the band edge emission, was realized in the AIS-based QD-LED. However, the EL spectra included a large defect emission component, together with the band edge emission. The defect emission was attributed to electrons flowing in the emitting layer (EML) being easily trapped at defect levels in the QDs. The addition of tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB) as an electron transporting material to the EML effectively suppressed the defect emission. The radiation-energy ratio of the band edge emission to the total emission was 50% in the QD-LED without 3TPYMB and was improved to 64% in the QD-LED with 3TPYMB; this ratio was comparable to that in the PL spectrum of the AIS core/shell QD film. The addition of 3TPYMB improved electron injection into the QDs and the carrier balance in the EML. As a result, the defect emission was suppressed and the EL characteristics were improved.