• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.1
• /
• pp.88-93
• /
• 2024

To evaluate the possibility as a multi-level memory medium for the Ge₂Sb₂Te₅/TiN/W-doped Ge₂Sb₂Te₅ cell structure, the crystallization rate and stabilization characteristics according to voltage (V)- and current (I)- pulse sweeping were investigated. In the cell structures prepared by a magnetron sputtering system on a p-type Si (100) substrate, the Ge₂Sb₂Te₅ and W-doped Ge₂Sb₂Te₅ thin films were separated by a barrier metal, TiN, and the individual thicknesses were varied, but the total thickness was fixed at 200 nm. All cell structures exhibited relatively stable multi-level states of high-middle-low resistance (HR-MR-LR), which guarantee the reliability of the multilevel phase-change random access memory (PRAM). The amorphousto-multilevel crystallization rate was evaluated from a graph of resistance (R) vs. pulse duration (T) obtained by the nanoscaled pulse sweeping at a fixed applied voltage (12 V). For all structures, the phase-change rates of HR→MR and MR→LR were estimated to be approximately t<20 ns and t<40 ns, respectively, and the states were relatively stable. We believe that the doublestack structure of an appropriate Ge-Sb-Te film separated by barrier metal (TiN) can be optimized for high-speed and stable multilevel PRAM.

• Microbiology and Biotechnology Letters
• /
• v.6 no.4
• /
• pp.173-179
• /
• 1978

1) To study the productivity of single cell protein from the n-paraffin utilizing yeast, 235 yeast strains were isolatea from 90 samples 2) Optimum cell growth temperature of three strains selected was 40~45$^{\circ}C$ and these were identified as Candida tropicalis, Candida krusei and Torulopsis molischiana. 3) A-28 strain easily assimilated tetradecane, hexadecane and octadecane, but B-8 strain and C-15 strain assimilated more hexadecane than other n-paraffins. 4) Out of the selected three strains, the mass doubling time, specific growth rate and cell yield were 3.4~4.0 hours, 0.170~0.215, 86~98%, respectively. 5) Crude protein, fat, fiber, ash and nitrogen free extract of the selected three strains were found to be 48.2~61.2% 3.7~8.0%, 3.5~4.2%, 5.6~6.7%, 23.5~31.8%, respectively, and thiamine and riboflavin contents of dried yeast cell were 0.78~0.93 mg% and 6.03~7.3 mg%, respectively. 6) Yeast protein contained evenly most of amino acid, but the sulfur-containing amino acids were particularly low.

• Korean Journal of Veterinary Service
• /
• v.42 no.4
• /
• pp.169-175
• /
• 2019

Naegleria fowleri, a pathogenic free-living amoeba, leads to a fatal infection known as primary amebic meningoencephalitis (PAM) in human and animals. PAM is an acute, fulminant, necrotizing, and hemorrhagic disease that leads to death in approximately seven days. In this study, we investigate the cytotoxicity of target cells and the secreted molecules of N. fowleri under the non-contact condition. The target cell (U87MG cell) treated with N. fowleri lysates showed no morphological changes and no cytotoxicity. By contrast, the U87MG cells co-cultured with N. fowleri trophozoites under the non-contact condition induced morphological changes and reduction in number. When U87MG cells were co-cultured with N. fowleri trophozoites under the non-contact condition for 30 min, 2 hr, and 4 hr, the levels of cytotoxicity of target cells were 32.3, 35.5, and 37.8%, respectively. Particularly, when the ratio of amoeba to target cells is 10 to 1, the level of cytotoxicity of target cells was 49.7% at 30 min. To show the proteins secreted from N. fowleri under the non-contact condition, we carried out 2D electrophoresis and observed 6 major proteins. Finally, these results suggest that the molecules released from N. fowleri under the non-contact condition induce the cell death and this process is an important step in pathogenesis of N. fowleri.

• Nutrition Research and Practice
• /
• v.13 no.5
• /
• pp.384-392
• /
• 2019

BACKGROUND/OBJECTIVES: Enteral nutrition formulas with immune-enhancing nutrients, such as n-3 fatty acids, may manage patients' nutritional status and pathophysiological processes. The aim of our study was to investigate natural killer (NK) cell activity alterations and related cytokine changes resulting from feeding with soybean oil-containing enteral nutrition formula (control group) and plant-derived n-3 fatty acid-enriched enteral nutrition formula. SUBJECTS/METHODS: Subjects participated for 14 consecutive days and consumed enteral formula containing canola and flaxseed oil (n3EN, test group) in nonsurgical patients hospitalized for rehabilitation. Blood samples were collected on the first day and 14 days after the consumption of each formula daily, and anthropometric parameters were collected. Hematology and biochemical values were analyzed, and NK cell activities and serum cytokine concentration were measured. A total of sixty subjects were included in the analysis, excluding dropouts. RESULTS: No significant differences were found in biochemical parameters. The n3EN group's NK cell activities at effector:tumor cell ratios of 10:1, 5:1, 2.5:1 and 0.625:1 were significantly higher than those of the control group after two weeks (P < 0.05). However, there were no statistically significant differences in serum cytokine interleukin (IL)-12, $interferon-{\gamma}$, $IL-1{\beta}$, IL-6 and tumor necrosis $factor-{\alpha}$ values between the two groups. CONCLUSIONS: In conclusion, this study elucidates the beneficial effects of plant-derived n-3 fatty acid supplementation in enteral formula on NK cell activity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.10
• /
• pp.844-849
• /
• 2011

Two kind of Ag-pastes were prepared for integrating the bulk Si solar cell. One is the Ag-paste with Pb-based glass frit and the other is that with Bi-based glass frit. The pastes were the mixture of 84 wt% Ag, 2 wt% glass frit, 11 wt% solvent of buthyl cabitol acetate, and 2 wt% additives. After fabricating the Ag-pastes, they was coated on a $SiN_x$/n+/p- stacks of a commercial mono-Si solar cell. The solar cell efficiency was 17.6% in the case of the Pb-based Ag-paste. However that was 16.2% in the solar cell integrated with the Bi-based Ag-paste. The lower performance in Bi-based Ag-paste was caused by the higher series resistance and the lower shunt resistance in comparison with the Pb-based Ag-paste.

• Journal of Life Science
• /
• v.19 no.1
• /
• pp.1-8
• /
• 2009

In this paper, to elucidate the further mechanisms of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced growth arrest, we investigated the effect of MNNG on cell cycle and proliferation in U937 cells, a p53-null human myeloid leukemia cell line. It was found that MNNG causes an arrest at the G2/M phase of the cell cycle and induces apoptosis, which is closely correlated to inhibition of cyclin B1 and cyelin-dependent kinase (Cdk) 2-associated kinase activities. MNNG treatment in. creased protein and mRNA levels of the Cdk inhibitor p21(WAF1/CIP1), and activated the reporter construct of a p21 promoter. By using p21 promoter deletion constructs, the MNNG-responsive element was mapped to a region between 113 and 61 relative to the transcription start site. These data indicate that in U937 cells MNNG can circumvent the loss of wild-type p53 function and induce critical downstream regulatory events leading to transcriptional activation of p21. Present results indicate that the p53-independent up-regulation of p21 by MNNG is likely responsible for the inhibition of cyclin/Cdk complex kinase activity rather than the down-regulation of cyclins and Cdks expression. These novel phenomena have not been previously described and provide important new insights into the possible biological effects of MNNG.

• IMMUNE NETWORK
• /
• v.23 no.2
• /
• pp.14.1-14.14
• /
• 2023

Immune status including the immune cells and cytokine profiles has been implicated in the development of endometriosis. In this study, we analyzed Th17 cells and IL-17A in peritoneal fluid (PF) and endometrial tissues of patients with (n=10) and without (n=26) endometriosis. Our study has shown increased Th17 cell population and IL-17A level in PF with endometriosis patients. To determine the roles of IL-17A and Th17 cells in the development of endometriosis, the effect of IL-17A, major cytokine of Th17, on endometrial cells isolated from endometriotic tissues was examined. Recombinant IL-17A promoted survival of endometrial cells accompanied by increased expression of anti-apoptotic genes, including Bcl-2 and MCL1, and the activation of ERK1/2 signaling. In addition, treatment of IL-17A to endometrial cells inhibited NK cell mediated cytotoxicity and induced HLA-G expression on endometrial cells. IL-17A also promoted migration of endometrial cells. Our data suggest that Th17 cells and IL-17A play critical roles in the development of endometriosis by promoting endometrial cell survival and conferring a resistance to NK cell cytotoxicity through the activation of ERK1/2 signaling. Targeting IL-17A has potential as a new strategy for the treatment of endometriosis.

• Archives of Pharmacal Research
• /
• v.25 no.4
• /
• pp.421-427
• /
• 2002

For probing the importance of planarity of imidazolidinone motif of 4-phenyl-1-(N-acylindoline-5-sulfonyl)imidazolidinones 1 for their cytotoxicity, 4-phenyl-1-(N-acylindoline-5-sulfonyl)[1,2,5]thiadiazolidine-1,1-dioxides 2 were prepared and their cytotoxicity were measured against human lung carcinoma (A549), human colon carcinoma (COLO205), human ovarian cancer (SK-OV-3), human leukemic cancer (K562), and murine colon adenocarcinoma (Colon26) cell lines in vitro. Although only carbonyl moiety of imidazolidinone ring was replaced with sulfonyl group, compounds 2 do not show any activity against all five cancer cell lines unlike 1. Therefore the planarity of imidazolidinone ring of 1 should be an important factor for their cytotoxic activity.

• The Korean Journal of Pharmacology
• /
• v.22 no.2
• /
• pp.123-127
• /
• 1986

n-Butyrate (n-BT A) increased the rate and number of infectious units produced in the in vitro reactivation of latent herpes simplex virus. While the mechanism of action of n-BT A is obscure, a continuous presence of n-BT A is necessary for its inductive effect.

• Journal of Nutrition and Health
• /
• v.27 no.6
• /
• pp.552-562
• /
• 1994

The study was designed to observe the effect of different dietary fats on the incidence of colorectal tumor and in vivo cell proliferation in colon carcinogenesis. Male Sprague Dawley rats were intrarectally infused with chemical carcinogen(methylnitrosourea, MNU) and fed 16%(w/w) fat diet containing one of dietary fats(beef tallow, corn oil, perilla oil) for 30 weeks. To measure in vivo cell proliferation, the incorporation of 5-bromo-2-deoxyuridine(BrdU) into DNA was localized using the monoclonal anti-BrdU antibody. Large number of tumors were found in the distal colon and tumor incidence was increased in the order of perilla oil(57.7%)$\alpha$-linolenic acid rich in perilla oil could have a protective effect against colon cancer compared to saturated fatty acid or n-6 linoleic acid.