Showing papers by "Sungkyunkwan University published in 1992"
60 citations
TL;DR: In this paper, an extrapolation method is proposed to determine the stress intensity factors of an interface crack in anisotropic dissimilar materials by numerical methods such as FEM or BEM.
55 citations
TL;DR: The present study suggests that scriptaid may be effective in growth suppression and cell cycle arrest and in the reversal of repressive chromatin marks at the promoter region of a hypermethylated p16 gene in colorectal cancer.
Abstract: Histone deacetylase inhibitors (HDACIs) are involved in cell growth, apoptosis and differentiation. This study aimed to investigate the effects of HDACI scriptaid on histone modification, demethylation, cell growth, cell cycle and apoptosis in the RKO colorectal cancer cell line and screening for scriptaid-induced genes. RKO cells were treated with 5-aza-2'-deoxycytidine (5-aza-dC), trichostatin A (TSA) or scriptaid at different concentrations. Histone modification and methylation status of a silenced p16 gene were analyzed using chromatin immunoprecipitation and methylation-specific PCR, respectively. Flow cytometry was performed for the analysis of cell cycle and apoptosis. Scriptaid-induced expression was analyzed using Human OneArray chip. Scriptaid resulted in the demethylation and re-expression of a hypermethylated p16 gene along with 5-aza-dC synergistically in the RKO cells, but not alone. Scriptaid induced modifications of core histone tails important in euchromatin structure: increases in acetyl-H3-K9 and dimethyl-H3-K4 and a decrease in dimethyl-H3-K9. Cell growth was inhibited by scriptaid in a dose-dependent manner. Cell cycle analysis showed that scriptaid induced G1 arrest at 0.5 and 1.0 microM concentrations and G1 and G2/M arrest at 2.0 microM. Scriptaid did not have a significant effect on apoptosis in RKO cells. An altered expression of 278 genes was observed in RKO cells in response to scriptaid treatment. In conclusion, the present study suggests that scriptaid may be effective in growth suppression and cell cycle arrest and in the reversal of repressive chromatin marks at the promoter region of a hypermethylated p16 gene in colorectal cancer.
35 citations
TL;DR: In this article, a Z 4 -quadratic function on π 2 for nonorientable 4-manifolds is defined and it is shown that it is homotopy invariant.
Abstract: We define a Z 4 -quadratic function on π 2 for nonorientable 4-manifolds and show that it is a homotopy invariant. We then use it to distinguish homotopy types of certain manifolds that arose from an analysis of toral action on nonorientable 4-manifolds
22 citations
TL;DR: A method for the quantitative determination of the nineteen protein amino acids by gas chromatography is described in this article, where the amino acids were allowed to react with isobutyl chloroformate in a basic aqueous medium and the resulting N(O,S)-isobuthyloxycarbonyl (isoBOC) amino acids are extracted into an organic solvent after acidification.
20 citations
TL;DR: The results suggest that the reconstruction of the Mo(001) surface reconstruction should occur essentially by Peierls-type 2kF instabilities with significant matrix element effects.
Abstract: We report results of an angle-resolved photoemission study to elucidate the driving mechanism of the Mo(001) surface reconstruction. We find, for the first time, a remarkable change of the shapes of Fermi contours upon cooling, which reveals a significant nesting at ${\mathit{k}}_{\mathrm{\ensuremath{\parallel}}}$=0.65 A${\mathrm{\r{}}}^{\mathrm{\ensuremath{-}}1}$, extended 0.30 A${\mathrm{\r{}}}^{\mathrm{\ensuremath{-}}1}$ perpendicular to the \ensuremath{\Sigma}\ifmmode\bar\else\textasciimacron\fi{} axis. The results suggest that the reconstruction should occur essentially by Peierls-type 2${\mathit{k}}_{\mathit{F}}$ instabilities with significant matrix-element effects.
17 citations
TL;DR: In this paper, the authors study the defense expenditures of the USA and the USSR, explicitly avoiding two limitations: most of them do not test the hypotheses of causality that they include, but simply use them as a point of departure, and those that do test causality are restricted to conceptual models with very few explanatory variables.
Abstract: Statistical studies of the determinants of defense expenditures have been criticized on two counts: (a) most of them do not test the hypotheses of causality that they include, but simply use them as a point of departure, and (b) those that do test causality are restricted to conceptual models with very few explanatory variables. The objective of this paper is to study the defense expenditures of the USA and the USSR, explicitly avoiding these two limitations. This is done using elementary statistical methods in somewhat unorthodox ways. The conclusions of the analyses are carefully compared with those obtained by other authors and the differences encountered are explained as far as possible. The analyses and comparisons show that the defense expenditures of the USA are determined by their own inertia and by political factors within the country, while those of the USSR are determined by their own inertia and the conditions of relations with the USA. The interest of these results is not in their novelty, bu...
14 citations
TL;DR: In this paper, the fundamental solutions of BEM are systematically classified and analyzed according to the kind of characteristic roots for anisotropic or orthotropic materials, and when the characteristic roots of orthotropic material are equal, they call these materials pseudo-isotropic materials.
9 citations
01 Jan 1992
TL;DR: It is quite natural that scale-up of insect cell culture would be a challenging scientific and technological undertaking to ensure the efficient production of various significant products for human health and medicine.
Abstract: Protein expression systems based on the Autographa californica nuclear polyhedrosis virus (AcNPV) have wide applicability as an alternative to prokaryotic or other eukaryotic expression system (1-5). However, the application of the baculovirus expression systems has been limited by difficulties in scale-up of insect cell culture (6-7). Therefore, it is quite natural that scale-up of insect cell culture would be a challenging scientific and technological undertaking to ensure the efficient production of various significant products for human health and medicine.
TL;DR: In this paper, the inverse secondary equilibrium isotope effects of Rh(I)-C 2 H 4 and RH(I) C 2 H 3 D were directly measured using a gas chromatographic column of dicarbonyl-rhodium-trifluoroacetyl-1 R -camphorate in squalane solution at 283-333 K.