Sang Ah Yi

A pregnane steroid, 3α-hydroxy-pregn-7-ene-6,20-dione (1), was isolated from a Hydractinia-associated Cladosporium sphaerospermum SW67 by repetitive column chromatographic separation and high-performance liquid chromatography (HPLC) purification. The planar structure of 1 was elucidated from the analysis of the spectroscopic data (1D and 2D NMR spectra) and LC-MS data. The absolute configuration of 1 was determined by interpretation of ROESY spectrum of 1, together with the comparison of reporte

Transparent conducting oxide Al-modified (2 wt.%) ZnO (AZO) was deposited on a GaN/Al2O3 substrate by rf magnetron sputtering at a substrate temperature of 400 C. With the help of a small lattice mismatch (about 1.9 %) and structural similarity (hexagon on hexagon epitaxy), the AZO film was epitaxially grown on the GaN substrate. This was investigated by four-circle X-ray diffractometer by using monochromatized Cu K1 radiation. The AZO film was well oriented to the lattice of GaN on the a . b pl

Stimulation of mast cells through the high affi nity IgE receptor (FcεRI) induces degranulation, lipid mediator release, and cytokine secretion leading to allergic reactions. Although various signaling pathways have been characterized to be involved in the FcεRImediated responses, little is known about the precious mechanism for the expression of tumor necrosis factor-α (TNF-α) in mast cells. Here, we report that rapamycin, a specifi c inhibitor of mammalian target of rapamycin (mTOR), reduces t

We investigated oxygen defect states in SrTiO3 (STO) thin films by using photoluminescence spectroscopy and spectroscopic ellipsometry. The oxygen-deficient STO homoepitaxial films were fabricated by using different oxygen partial pressures and flow rates for controlling the amount of oxygen vacancies systematically. The visible emission and absorption increased simultaneously with increasing oxygen vacancy concentration in the STO thin films. Given the absolute values of the optical constants,

Metal-ferroelectric-metal (MFM)-structured (Ba0.5Sr0.5)TiO3 (BST) thin films were deposited on a Pt(111)/TiO2/SiO2/Si substrate by pulsed laser deposition. The textures of BST films, such as those with (111), (100), and (110) orientations, were successfully controlled by oxygen partial pressure and laser energy under deposition. In spite of the use of (111)-oriented platinized silicon substrates, highly (100)-textured BST film was formed by control of the oxygen flow rate. Voltagedependent diele

S6K1 is a key regulator of cell growth, cell size, and metabolism. Although the role of cytosolic S6K1 in cellular processes is well established, the function of S6K1 in the nucleus remains poorly understood. Our recent study has revealed that S6K1 is translocated into the nucleus upon adipogenic stimulus where it directly binds to and phosphorylates H2B at serine 36. Such phosphorylation promotes EZH2 recruitment and subsequent histone H3K27 trimethylation on the promoter of its target genes in

The functional properties of devices based on perovskite oxides depend strongly on the growth modes that dramatically affect surface morphology and microstructure of the hetero-structured thin films. To achieve atomically flat surface morphology, which is usually a necessity for the high quality devices, understanding of the growth mechanism of heteroepitaxial thin film is indispensable. In this study, we explore heteroepitaxial growth kinetics of the SrRuO3 using intermittent growth scheme of p