The xerographic properties of dual-layer photoreceptors having different molecular structure, are described with respect to their photosensitivities. A correlation between the absorption wavelength and the photosensitivity was found. A study on device optimization of 3,4,9,10-perylenetetracarboxylic diimides was carried out. The dual-layer photoreceptor device exhibited low dark decay and flat spectral response from 450-750 nm. The spectral sensitivity of the dual-layer photoreceptor extends to the near-IR region.

A newly synthesized nitroxide radical,4-ferrocenecarboxyI-2,2,6,6-tetramethyI piperidine-1-oxyl(FC-TEMPO), was firstly encapsulated in the poly(DL-Lactic acid) (PLA) nanoparticles by the modified spontancous emulsification solvent diffusion method. The formation of the nanoparticles with diameters of 120

Low molecular weight nitroxides are widely used as electron paramagentic resonance(EPR)-detectable spin labels in the biological and pathological areas. A novel nitroxide derivative, 4-ferrocenecarboxyl-2,2,6,6-tetramethyl piperidine-1-oxyl(FC-TEMPO), was synthesized for evaluating the effects of spin label compounds on tumor cells and firstly its biological effects on tumor and normal cells were evaluated. The cytotoxicity of FC-TEMPO in the hige metastatic lung carcinoma cells(95-D) showed that it markedly inhibited the viabillity of cancer cells in a dose-dependent manner, while it was less toxic to a normal human cell line. Further studies found that FC-TEMPO suppressed the growth of tumor cells by induced apoptosis through activating caspase-3 but not caspase-8 which was proved by caspase inhibitors, and the cell cycle arrest at G; phase. Moreover, the concomitant increase of superoxide dismutase(SOD) and catalase (CAT) activity was boserved. Taken together, these resluts right provide a base for further anticancer investigations of nitroxides and their potential pharmacologicalapplications

Anisotropic visible and infrared(IR).absorption spectra of Langmuir-Blodgett(LB).films of mutually mixed merocyanine dyes deposited with Cd2+ ions were recorded. In these films, a merocyanine dye ‘DO’ is included in J-aggregates, although in LB films of DO(not mixed with other merocyanine dyes), DO itself does not form J-aggregates. A difference spectrum method successfully separated the spectra observed into two components, one of which was due to J-aggregates. This component includes the contribution of the J-aggregated DO molecules and compared well with the absorption spectra observed for LB films of DO. This comparison detected, for the aggregated DO, red shifts of several IR bands due to softening of the bond alternation in the central conjugated system of the molecule, which thus suggested that intramolecular charge transfer is enhanced by the formation of J-aggregates.

J-aggregates in Langmuir
Blodgett (LB). films of mutually mixed merocyanine dyes were characterized by using Fourier transform infrared(FT-IR).spectroscopy. Two merocyanine dyes, one which forms and one which does not form J-aggregates in their LB films with fatty acids and divalent metals, so-called 6MeDS and DO, respectively, were used in this study. In LB films of DO-6MeDS mutual mixtures, most DO molecules are included in J-aggregates. The IR spectra of these films were measured and compared with linear combinations of the spectra for DO and 6MeDS films. The difference between the measured and the calculated IR spectra reflects the difference between the electronic state of J-aggregated DO and that of monomeric DO. The results suggest an enhancement of the intramolecular charge transfer induced by the formation of J-aggregates.