• Microbiology and Biotechnology Letters
• /
• v.50 no.2
• /
• pp.301-309
• /
• 2022

Helicobacter pylori (H. pylori) establishes infection in the human gastric mucosa for a long time and causes severe gastric diseases such as peptic ulcer and gastric cancer. When H. pylori is exposed to the antibacterial agents or inhibitors, the expression of pathogenic associated genes could be altered. In this study, we analyzed the transcriptional changes of H. pylori genes induced by zerumbone treatment. RNA expression changes were analyzed using next-generation sequencing (NGS), and then reverse transcription-polymerase chain reaction (RT-PCR) was performed to verify the results. As a result of NGS analysis, a total of 23 out of 1,632 genes were differentially expressed by zerumbone treatment. RT-PCR confirmed that zerumbone treatment regulated the expression level of 14 genes. Among the genes associated with DNA replication, transcription, virulence factors and T4SS components, 10 genes (dnaE, dnaQ, rpoA, rpoD, secA, flgE, flhA, virB5, virB8 and virB9) were significantly down-regulated and 4 genes (flaA, flaB, virB4 and virD4) were up-regulated. The results of our current study imply that zerumbone might be a potential therapeutic agent for H. pylori infection by regulating factors related to various H. pylori pathogenicity.

• Transactions of Materials Processing
• /
• v.17 no.7
• /
• pp.466-472
• /
• 2008

In this paper, tension tests and formability tests are performed to construct a database related to mechanical properties and the formability of the AZ31B Mg alloy sheet. A forming test with a hemi-spherical punch is conducted at varying temperatures to establish a forming limit diagram. In order to verify the applicability of the analysis using the conventional flow hardening model, a finite element analysis is performed on the hemi-spherical punch forming process and the results are compared with experimental ones. The study investigates problems involving a computational analysis that does not consider flow softening of the magnesium alloy at elevated temperatures.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.366-369
• /
• 2008

In this paper, tension tests and formability tests are performed to construct a database related to mechanical properties and the formability of the AZ31B Mg alloy sheet. A forming test with a hemi-spherical punch is conducted at varying temperatures to establish a forming limit diagram. In order to verify the applicability of the analysis using the conventional flow hardening model, a finite element analysis is performed on the hemi-spherical punch forming process and the results are compared with experimental ones. The study investigates problems involving a computational analysis that does not consider flow softening of the magnesium alloy at elevated temperatures.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.857-858
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1205-1206
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.861-862
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.513-514
• /
• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.05a
• /
• pp.215-216
• /
• 2010

• Nuclear Engineering and Technology
• /
• v.30 no.1
• /
• pp.26-39
• /
• 1998

The containment pressure and temperature transient analysis computer code CONTEMPT4/MOD5 is modified to incorporate the passive containment cooling models. The correlations are selected from the existing experimental heat transfer correlations to model the natural and mixed convection in annular space between the containment shell and the shield building. The evaporative heat transfer of the water film on the outer shell of the containment is modeled using the correlations derived from the analogy between the heat and mass transfer. The modified code is applied to the Ap600 containment transient analysis for the model verification and the results are compared to the results of GOTHIC calculation done by Westinghouse. Also, d series of parametric sensitivity studies of heat transfer correlations, water film ratio and delay time of the wet cooling on the containment peak pressure and temperature following LOCA are performed for the containment of 1000MWe passive plant, KP1000.

• Korean Journal of Pharmacognosy
• /
• v.16 no.3
• /
• pp.175-179
• /
• 1985

The optimal condition for the determination of saikosaponin a and d, the major pharmacologically active saponins of the roots of Bupleurum falcatum, was studied with the conversion of these saponins into diene saponins $(saikosaponin\;b_1\;and\;b_2)$. The complete separation and quantitative analysis of these saponins were performed by the method of high performance liquid chromatography using $NH_2$ column. The conversion of saikosaponin a and d into diene saponins under gastric pH was calculated. Thirty-three percent of saikosaponin a was converted to saikosaponin $b_1$ and 63 percent of saikosaponin d was converted to saikosaponin $b_2$.