• Journal of Korean Society of Steel Construction
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• v.8 no.4 s.29
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• pp.133-133
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• 1996

Application of the relationship $da/dN=C({\Delta}K)^{m}$ is effective in the analysis of fatigue crack growth life. The values of material constant C and m have great influences on the predicted fatigue life and the relationship between fatigue crack growth rate(da/dN) and stress intensity factor range(${\Delta}K$) is effective in fatigue crack growth behavior. In this paper, fatigue crack growth behavior of the welded joints in HT60 grade TMCP(Thermo Machanical Control Process) steel have been studied. To evalute the fatigue crack growth rates of HT60 grade TMCP steel, fatigue test was performed by base metal(BM), heat affected zone(HAZ) and weld metal(WM) in TMCP steel at room temperature. We determined the relationship of $da/dN-{\Delta}K$ by correlation between C and m obtained from the Paris-Erdogan power law data supplied HT60 grade TMCP steel. The obtained results from this study indicate that fatigue crack growth rate of TMCP steel is not influenced by softening effect which occurs in the HAZ when high heat input weld is carried out. Softening effects, which affect fatigue properties. are shown that it is not affected to the fatigue growth rates significantly.

• YAKHAK HOEJI
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• v.59 no.4
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• pp.164-169
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• 2015

In the present study, we determined the effect of $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) in the mice model bearing xenografts of HT-29 human colon cancer cell line. Data from the cytotoxicity assay displayed that $18{\beta}$-GA induced cell death in HT-29. The cytotoxicity was enhanced as the $18{\beta}$-GA treatment was prolonged. In case of 72 hrs treatment, $LD_{50}$ of $18{\beta}$-GA was approximately $90{\mu}M$, and the efficacy at $100{\mu}M$ of $18{\beta}$-GA appeared to be equivalent to that of doxorubicin at $1{\mu}M$. Based on the in vitro data, we tested the anti-tumor effect of $18{\beta}$-GA in thymic mice (Balb/c strain). Xenograft tumors were generated by subcutaneous injection of HT-29 ($3{\times}10^6cells/mouse$) to mice and the mice were treated intraperitoneally with $18{\beta}$-GA ($50{\mu}g/time/mouse$) every other day for 4 times. The tumor volumes were measured for a period of 14 days. Data displayed that the $18{\beta}$-GA treatment reduced the tumor volumes (P < 0.05) as compared to control mice. However, this activity was demolished when athymic mice (Balb/c nu/nu) were used instead of thymic mice. This observation appeared that T lymphocyte played an important role in the anti-tumor activity. In conclusion, our results indicate that $18{\beta}$-GA has anti-tumor activity in HT-29 tumor-bearing mice, which may be associated with T cells.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.260-264
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• 2007

Gleditsiae Semen (GS) has been used in both Korea and China as herbal medicine for the treatment of cephalalgia, catharsis, and other diseases. However, the apoptosis of GS against human cancer cells has not previously been investigated. The primary objective of this study was to determine the mechanisms inherent in GS-induced cytotoxicity and apoptosis, using methanolic extract of GS (GSE) in HT-29 human colon carcinoma cells. We found that GSE induced cytotoxicity in HT-29 cells in a dose-dependent manner, and this effect was verified via a lactate dehydrogenase release assay and a colony formation assay. In particular, HT-29 cells showed extensive cell death when treated with $50\;{\mu}g/mL$ of GSE; the calculated $IC_{50}$ value was $20\;{\mu}g/mL$. It induced characteristic apoptotic signs in HT-29 cells, including chromatin condensation and DNA fragmentation, occurring within 6-24 hr when the cells were treated at a concentration of $50\;{\mu}g/mL$. Interestingly, we detected the activation of caspase-3 and -9, but not caspase-8, and apoptotic bodies in GSE-treated HT-29 cells. Collectively, our results indicate that GSE induces apoptosis via a mitochondria-mediated apoptotic pathway, and these findings may be significant with regard to the development of a new drug for the treatment of human colon carcinoma cells.

• Microbiology and Biotechnology Letters
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• v.46 no.2
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• pp.102-110
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• 2018

A bacterial strain capable of metabolizing myo-inositol (MI) and converting to other substances was isolated from soil of orchard. The isolate, named YB-46, was grown on minimal medium supplemented with MI as the sole carbon source and was presumed to belonging to genus Enterobacter according to the 16S rDNA sequence. Escherichia coli transformant converting MI into unknown metabolites was selected from a metagenomic library prepared with fosmid pCC1FOS vector. Plasmid was isolated from the transformant, and the inserted gene was partially sequenced. From the nucleotide sequence, an iolG gene was identified to encode myo-inositol dehydrogenase (IolG) consisting of 336 amino residues. The IolG showed amino acid sequence similarity of about 50% with IolG of Enterobacter aerogenes and Bacillus subtilis. The His-tagged IolG (HtIolG) fused with hexahistidine at C-terminus was produced and purified from cell extract of recombinant E. coli. The purified HtIolG showed maximal activity at $45^{\circ}C$ and pH 10.5 with the highest activity for MI and D-glucose, and more than 90% of maximal activity for D-chiro-inositol, D-mannitol and D-xylose. $K_m$ and $V_{max}$ values of the HtIolG for MI were 1.83 mM and $0.724{\mu}mol/min/mg$ under the optimal reaction condition, respectively. The activity of HtIolG was increased 1.7 folds by $Zn^{2+}$, but was significantly inhibited by $Co^{2+}$ and SDS.

• Journal of Marine Life Science
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• v.8 no.1
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• pp.32-42
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• 2023

Fish reproduction is regulated by various neurohormones secreted from the brain and gonadotropic hormones secreted from the pituitary. Reproduction of eel (Anguilla japonica) is also regulated by these hormones. However, how the neurohormones regulate the secretion of pituitary hormones during sexual maturation is not completely understood. Previous studies have shown that neurohormones such as progesterone (P4), melatonin and serotonin (5-HT) are involved in the regulation of reproductive processes in some fish. In this study, the eel pituitary was primary cultured, and stabilized pituitary cells were treated with P4, 17β-estradiol (E2), melatonin, or 5-HT. The effect of these treatments on the expression of FSHβ, LHβ, GH and SL mRNA was, then, investigated. P4 increased the expression of FSHβ and LHβ in pituitary cells, and melatonin increased the expression of GH and SL as well as FSHβ and LHβ. However, 5-HT did not significantly affect the expression of these mRNA. These results suggest that P4 and melatonin may play some important roles in the early sexual maturation of eels.

• Journal of The Geomorphological Association of Korea
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• v.26 no.4
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• pp.81-96
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• 2019

The Yeongdeok 53m marine terrace (Y₅₃mT), Y₄₃mT, Y₃₃mT, Y₂₄mT, Y₁₉mT and Y₁₁mT distributed along the Yeongdeok coast, southeastern Korean Peninsula are well compared with the thalassostatic terraces of the high terrace 1 (ℓHT₁ ; 51m of the relative heights from the river floor), high terrace 2 (ℓHT₂ ; 43m), middle terrace 1 (ℓMT₁ ; 32m), middle terrace 2 (ℓMT₂ ; 25m), lower terrace 1 (ℓLT₁ ; 18m) and lower terrace 2 (ℓLT₂ ; 10m) respectively, developed along the lower reaches of the Chucksan-cheon and Obo-cheon rivers, judging from the comparison of paleosols (red soils) between the above marine and thalassostatic terraces. Using the Y₁₉mT of the MIS 5e as the key surface, we propose that the terraces of the Y₅₃mT and ℓHT₁, Y₄₃mT and ℓHT₂, T₃₃mT and ℓMT₁, Y₂₄mT and ℓMT₂, Y₁₉mT and ℓLT₁, and Y₁₁mT and ℓLT₂ have been formed at the MIS 11, 9, 7e and 7a (or 7a), 5e and 5a respectively. The red soils have been developed at the Y₁₉mT and ℓLT₁ and above them, but not on the Y₁₁mT and ℓLT₂ surfaces.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.4
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• pp.36-53
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• 2005

Purpose : The Purpose of this research was to investigate the effects of Haingkyunghonghwatang (HKHHT) on anti-inflammatory effects. Methods : As for the parameters of inflammation, levels of several inflammatory cytokines and chemical mediators were determined in mouse lung fibroblast cells(mLFC) and RAW264.7 cells. Also, changes in pathological features by drug treatment were investigated in the in vivo edema-induced rats by carrageenin/arachidonic acid or in the colitis-induced mice by DSS treatment. Results : The cytotoxicity of HKHHT on mLFC and RAW264.7 cells wasn't observed at 100, 50, 10, and $1{\mu}g/ml$ of The treatments. $IL-1{\beta}$, IL-6 and NOS-II mRNA expression of RAW264.7 cells was inhibited by The treatments in a dose-dependent manner. HKHHT treatment of RAW264.7cells(HtRc) inhibited $TNF-{\alpha}$ and COX-2 mRNA expression. HtRc significantly inhibited IL-6 and NO production. HtRc inhibited ROS production. HKHHT inhibited rat's paw edema induced by carrageenin or arachidonate treatment in all concentrations examined. The body weight and colon length of colitis-induced mice were recovered to a normal level by DSS treatment. Clinical disease levels were significantly improved compared to the control animals. HKHHT treatment of colitis-induced mice(HtCm) significantly increased hematological values such as WBC and RBC counts, Hgb and HCT levels, but decreased PLT values. HtCm decreased IL-6 and $TNF-{\alpha}$ production significantly HtCm significantly increased CD3+(T) cell counts. In contrast, HKHHT treatment decreased CD19+ B cell counts and CD3+/CD69+ significantly, and also decreased B/T ratio (%) though not significant. Conclusion : These results indicated that HKHHT could be used for treating diverse female diseases caused by the inflammation.

• Corrosion Science and Technology
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• v.22 no.1
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• pp.1-9
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• 2023

This work studied the inhibitory effect of the combination of benzoate-intercalated hydrotalcite (HT-BZ) and Ce³⁺-loaded clay (Clay-Ce) on carbon steel (CS). HT-BZ was prepared by the co-precipitation method and Clay-Ce was fabricated by a cation exchange reaction. HT-BZ and Clay-Ce were assessed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) coupled with zeta potential measurement. Electrochemical measurements coupled with scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) were used for studying the inhibitory action of the mixture of HT-BZ and Clay-Ce on steel electrodes immersed in 0.1 M NaCl. For comparison, the inhibitory effect of HT-BZ or Clay-Ce alone was also evaluated. The results showed that HT-BZ combined with Clay-Ce provided synergistic inhibition of the CS substrate. The mixture of 0.5 g/L HT-BZ + 0.5 g/L Clay-Ce provided 93.5% inhibition efficiency. The protective mechanism of the HT-BZ + Clay-Ce mixture consisted of the reaction of released BZ and Ce³⁺ and the deposition of HT-BZ and Clay-Ce structures on the CS substrate.

• Journal of Life Science
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• v.19 no.5
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• pp.633-638
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• 2009

We investigated the inhibitory effects of solvent extracts from dried tuna on the growth of cancer cell lines (HT1080 human fibrosarcoma and HT-29 human colon cancer cells) and $H_2O_2$-induced oxidative stress. Inhibitory effects of acetone with methylene chloride (A+M) and methanol (MeOH) extracts on the growth of HT1080 and HT-29 cancer cells increased in a dose dependent manner (p<0.05). The inhibitory effect was more significant on the growth of HT1080 cells, and A+M extracts had a higher inhibitory effect compared to MeOH extracts. The treatments of hexane, 85% aq. methanol, butanol and water fractions significantly inhibited the growth of both cancer cells (p<0.05). Among the fractions, hexane and 85% aq. methanol fractions showed higher inhibitory effects. In order to determine the protective effect on $H_2O_2$-induced oxidative stress, a DCHF-DA (dichlorodihydrofluorescin diacetate) assay was conducted. All fractions, including crude extracts of dried tuna, appeared to significantly reduce the levels of intracellular reactive oxygen species (ROS) with dose responses (p<0.05). Among the fractions, BuOH and 85% methanol fractions showed a higher protective effect on the production of lipid peroxides. These results indicate that the consumption of tuna may be recommended as a potent functional food for preventing cellular oxidation and cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6403-6407
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• 2012

Detoxifying enzymes are present in most epithelial cells of the human gastrointestinal tract where they protect against xenobiotics which may cause cancer. Induction of examples such as glutathione S-transferase (GST) and its thiol conjugate, glutathione (GSH) as well as NAD(P)H: quinoneoxidoreductase (NQO1) facilitate the excretion of carcinogens and thus preventing colon carcinogenesis. Pterostilbene, an analogue of resveratrol, has demonstrated numerous pharmacological activities linked with chemoprevention. This study was conducted to investigate the potential of pterostilbene as a chemopreventive agent using the HT-29 colon cancer cell line to study the modulation of GST and NQO1 activities as well as the GSH level. Initially, our group, established the optimum dose of 24 hours pterostilbene treatment using MTT assays. Then, effects of pterostilbene ($0-50{\mu}M$) on GST and NQO1 activity and GSH levels were determined using GST, NQO1 and Ellman assays, respectively. MTT assay of pterostilbene ($0-100{\mu}M$) showed no cytotoxicity toward the HT-29 cell line. Treatment increased GST activity in the cell line significantly (p<0.05) at 12.5 and $25.0{\mu}M$. In addition, treatment at $50{\mu}M$ increased the GSH level significantly (p<0.05). Pterostilbene also enhanced NQO1 activity significantly (p<0.05) at $12.5{\mu}M$ and $50{\mu}M$. Hence, pterostilbene is a potential chemopreventive agent capable of modulation of detoxifiying enzyme levels in HT-29 cells.