Showing papers by "Kangwon National University published in 1992"

Flavonoids from the aerial parts of Lonicera japonica

Abstract: Seven flavonoids were isolated from the aerial parts ofLinocera japonica. Their structures were characterized as hydnocarpin1, quercetin2, ochnaflavone3, ochnaflavone 4′-O-methylether4, astragalin5, isoquercitrin6, and rhoifolin7 by chemical and spectroscopic evidences.

Modified Glauber model II description for heavy-ion elastic scattering

Abstract: A modified Glauber model II for heavy-ion elastic scattering is presented by taking into account the deflection effect of the trajectory due to the real nuclear potential in addition to the Coulomb effect in the modified Glauber model I. It has been applied satisfactorily to the elastic scattering reactions $^{16}\mathrm{O}$${+}^{12}$C and $^{16}\mathrm{O}$${+}^{28}$Si at ${\mathit{E}}_{\mathrm{lab}}$=1503 MeV.

Transition to chaos in a dissipative standardlike map.

Abstract: We study the transition to chaos caused by overlap of resonances in a dissipative standardlike map exhibiting recurrence of invariant circles. In particular, the effects of the recurrence on the structure of a critical line at which the motion is always mode locked are investigated. When there is no recurrence of invariant circles, a smooth critical line exists. In the recurrence case, however, the critical line is folded back and has discontinuous parts. At this line the mode-locked intervals trace a folded devil's staircase with isolated parts. Scaling behavior of the complementary set to the folded staircase is also discussed

The pattern of gene expression and possible relation of steroidogenic genes in oligodendroglial tumors

Abstract: This study was supported by a grant of the Seoul National University Hospital (grant number: 32004031).

Intermediates Formed in the Reaction of Cytochrome c Oxidase with Oxygen

Abstract: Cytochrome c oxidase is the terminal enzyme in the electron transport chain. In this role, it catalyzes the transfer of four electrons from cytochrome c to di-oxygen, the physiological substrate. Oxygen binds to cytochrome c oxidase on the microsecond time scale and is fully reduced to water in milliseconds. An understanding of the molecular basis for the catalytic mechanism of the oxygen reduction has been sought after for many years but has remained elusive due to the difficulty in establishing the identity of each intermediate on this time scale by optical spectroscopic techniques. Recently, we [1–5] and others [6–11] have applied resonance Raman spectroscopy to the study of the oxygen reduction process and achieved considerable success. In this paper, we discuss the findings from the resonance Raman scattering experiments and based on these results present a model for the catalytic pathway.

Annealing of Metastable Recombination Centers in Hydrogenated Amorphous Silicon

Abstract: We report results on the annealing behaviors of light- and deposition-induced metastable recombination centers, as measured by steady-state photoconductivity, in undoped hydrogenated amorphous silicon. The relaxation time inferred from the stretched-exponential time law reveals a thermally activated behavior, and the activation energies are nearly identical in both (Ea=1.1eV). This value is much less than that of the light-induced darkconductivity relaxation (Ea=1.7eV) measured simultaneously with photoconductivity. While in the deposition-induced case both activation energies of dark- and photoconductivity relaxation time are identical. These results support that there is more than one kind of defect created by light exposure, and at least, as considering activation energies for annealing defects, the light-induced recombination center differ from other metastable defects.