• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.357-363
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• 2003

The aim of this work is the synthesis of a-C:H films from methane gas using surface spark discharge at the atmospheric pressure. Properties of these films have been investigated as functions of energy W delivered per a methane molecule in the discharge. The method enables the coatings to be deposited with high growth rates (up to $100 \mu\textrm{m}$/hour) onto large-area substrates. It is shown that the films consist of spherical granules with diameter of 20∼50 nm formed in the spark channel and then deposited onto the substrate. The best film characteristics such as minimum hydrogen-to-carbon atoms ratio H/C=0.69, maximum hardness $H_{v}$ =3 ㎬, the most dense packing of the granules and highest scratch resistance has been obtained under the condition of highest energy W of 40 eV. The deposited a-C:H coatings were found to be more soft and hydrogenated compared to the diamond-like hydrogenated (a-C:H) films which obtained by traditional plasmaenhanced chemical vapor deposition methods at low pressure (＜10 Torr). Nevertheless, these coatings can be potentially used for scratch protection of soft plastic materials since they are of an order harder than plastics but still transparent (the absorption coefficient is about $10^4$∼$10^{5}$ $m^{-1}$ At the same time the proposed method for fast deposition of a-C:H films makes this process less expensive compared to the conventional techniques. This advantage can widen the application field of. these films substantially.y.

• Korean Journal of Pharmacognosy
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• v.34 no.1 s.132
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• pp.91-99
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• 2003

Ras proteins play an important role in intracellular signal transduction pathways involved in cell growth and the mutated twas genes have been found in thirty percent of human cancers. Ras proteins (H-, K- and N-Ras) are small guanine nucleotide binding proteins that undergo a series of posttranslational modifications including the farnesylation onto cysteine 186 at C-terminal of Ras by farnesyl protein transferase (FPTase). This is a mandatory process for retention of transforming ability. Therefore, inhibitors of FPTase have a promising to be effective antitumor agents. In our screening program for FPTase inhibitors, the methanol extracts of 193 plants were screened for the inhibitory activity against FPTase partially purified from the rat brain. Extracts of 7species plants including Areca catechu, Saururus chinensis, Curcuma longa, Artemisa princeps, Paeonia suffruticosa, Spatholobus suberectus, Cinnamomum cassia, Cinnamomum japonicum inhibited more than 60% of FPTase activity at a concentration of $100\;{\mu}g/ml$.

• The Zoological Society Korea : Newsletter
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• v.12 no.2
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• pp.99.2-99
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• 1995

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.227.2-227
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• 1995

No Abstract, See Full Text

• Journal of Aquaculture
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• v.21 no.3
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• pp.125-132
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• 2008

Seed production of olive flounder Paralichthys olivaceus was performed in a pilot RAS. The growth of juvenile olive flounder and changes in water quality were monitored for the entire production period. The pilot RAS consisted of 8 circular culture tanks($4.0mD{\times}1.0mH$), 2 trickling biofilters($1.7mD{\times}2.0mH$), 2 protein skimmers ($0.8mD{\times}2.5mH$), and 4 sedimentation chambers($0.7mD{\times}1.5mH$). The culture surface area was about $100.5m^2$ and the actual working volume was about $106.9m^3$. As many as 300,000 fertilized olive flounder eggs were initially distributed into 2 culture tanks with the water temperature at $19.0^{\circ}C$. Live feeds such as rotifers and Artemia nauplii were fed until the 32nd day after hatching, and a commercial diet was fed from the 19th day to the end of the experiment. After 70 days, 150,256 juveniles with a body length of $65.8{\pm}3.9mm$ were produced in the RAS, with a daily growth rate for body length of 4.7%/day. At this time, the final culture density was 1,495 individuals $m^{-2}$, and 13.6 L of makeup water, 0.071 kW of electricity and 0.025 L of diesel fuel were used to produce a juvenile olive flounder. During metamorphosis of the larvae, the TAN concentration increased to 0.99 mg/L, which made the larvae sensitive to result in some mortality. However no more massive mortality occurred at the juvenile stage after metamorphosis even at a TAN concentration of 4.25 mg/L and a ${NO_2}^{-}-N$ concentration of 2.45 mg/L.

• Genomics & Informatics
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• v.4 no.4
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• pp.161-166
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• 2006

The establishment of DNA microarray technology has enabled high-throughput analysis and molecular profiling of various types of cancers. By using the gene expression data from microarray analysis we are able to investigate diagnostic applications at the molecular level. The most important step in the application of microarray technology to cancer diagnostics is the selection of specific markers from gene expression profiles. In order to select markers of Immortalization and transformation we used c-myc and $H-ras^{V12}$ oncogene-transfected NIH3T3 cells as our model system. We have identified 8751 differentially expressed genes in the immortalization/transformation model by multivariate permutation F-test (95% confidence, FDR<0.01). Using the support vector machine algorithm, we selected 13 discriminative genes which could be used to predict immortalization and transformation with perfect accuracy. We assayed $H-ras^{V12}$-transfected 'transformed' cells to validate our immortalization/transformation dassification system. The selected molecular markers generated valuable additional information for tumor diagnosis, prognosis and therapy development.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.903-909
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• 2002

Research in the cytokine field has grown exponentially in recent years, and the validity of such studies relies heavily on the appropriate measurement of levels of cytokines in various biological samples. Transforming growth factor (TGF)-$\beta$, a hormonally active polypeptide found in normal and transformed tissue, is a potent regulator of cell growth and differentiation. The most widely used bioassay for TGF-$\beta$ is the inhibition of the proliferation of mink lung epithelial cells. Though detection of [$^3$H]thymidine incorporation is more sensitive than the MTT assay, it presents some disadvantages due to the safety and disposal problems associated with radioisotopes. In this study, we attempted to ascertain the experimental conditions which could be used for measuring the in vitro biological activity of TGF-$\beta$ in a safer and more sensitive way compared with the currently available methods. We compared the commonly used method, the MTT assay, to the XTT assay using different parameters including cell number, incubation time and the wave length used for detecting the product. We examined the anti-proliferative activities of TGF-$\beta$ in three different cell lines: Mv-1-Lu mink lung epithelial cells, MCF10A human breast epithelial cells and H-ras-transformed MCF10A cells. Herein, we present an experimental protocol which provides the most sensitive method of quantifying the biological activity of TGF-$\beta$, with a detection limit of as low as 10 pg/ml: Mv-1-Lu or H-ras MCF10A cells ($1{\times}10^5/well$) were incubated with TGF-$\beta$ at $37^{\circ}C$ in a humidified $CO_2$ incubator for 24 hr followed by XTT treatment and determination of absorbance at 450 or 490 nm. Our results may contribute to the establishment of an in vitro bioassay system, which could be used for the satisfactory quantitation of TGF-$\beta$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.1024-1030
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• 1996

Capsaicin (8-methyl-N-vanillyl-6-nonenamide: CAP) is a mai or ingredient of hot pepper that has been used as a spicy food additive, preservative, and medicine. In this study, we evaluated the effect of dietary CAP on the selected proto-oncogene(c-jun, c-myc, H-ras, erbB, p53) expressions in various tissues of mice. Male ICR mice were divided into four groups and fed the experimental diets containing CAP at the levels of 0, 5, 20 and 100ppm for four weeks. Steady state RNA levels in various tissues were measured by slot blot hybridization assay. C-jun expression level was enhanced in stomach tissue from mice fed 20ppm CAP and significantly reduced from mice fed 100ppm CAP. The c-jun expression levels were differentially altered in organ-specific manner, Tumor suppressor gene p53 expression level appeared to be slightly increased in the liver from mice fed 20ppm CAP. These results suggested that dietary CAP differentially modulates c-jun and p53 expression in various organs.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.4
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• pp.143-148
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• 2002

Method of plasma-immersion ion deposition of hydrogenated DLC films on relatively thick flat dielectric substrates from plasma of not-self-sustained low-pressure gas arc discharge is suggested. Coating properties have been investigated experimentally, average energy Per a deposited carbon atom depending on discharge current has been calculated. Optimum deposition parameters lot obtaining sufficiently hard and transparent high-adhesive a-C:H films on a 4-mm thick glass substrates have been determined. Possibility to use these coatings for photo-tools protection from abrasion wear at low operating loads is shown in general.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.79-95
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• 1997

Purpose : Phospholipase C(PLC) isozymes play significant roles in signal transduction mechanism. $PLC-\gamma$ 1 is one of the key regulatory enzymes in signal transduction for cellular proliferation and differentiation. Ras oncoprotein, EGFR, and PKC are also known to be involved in cell growth. The exact mechanisms of these signal transduction following irradiation, however, were not clearly documented Thus, this study was Planned to determine the biological significance of PLC, ras oncoprotein, EGFR, and PKC in damage and regeneration of rat intestinal mucosa following irradiation. Material and Method : Sixty Sprague-Dawley rats were irradiated to entire body with a single dose of 8Gy. The rats were divided into S groups according to the sacrifice days after irradiation. The expression of PLC, ras oncoprotein, EGFR and PKC in each group were examined by the immunoblotting and immunohistochemistry. The histopathologic findings were observed using H&I stain, and the mitoses for the evidence of regeneration were counted using the light microscopy & PCNA kit. The Phosphoinositide(PI) hydrolyzing activity assay was also done for the indirect evaluation of $PLC-\gamma$ 1 activity. Results: In the immunohistochemistry , the expression of $PLC-{\beta}$ was negative for all grøups. The expression of $PLC-{\gamma}1$ was highest in the group III followed by group II in the proliferative zone of mucosa. The expression of $PKC-{\delta}1$ was strongly positive in group 1 followed by group II in the damaged surface epithelium. The above findings were also confirttled in the immunoblotting study. In the immunoblotting study, the expressions of $PLC-{\beta}$, $PLC-{\gamma}1$, and $PKC-{\delta}1$ were the same as the results of immunohis-tochemistry. The expression of ras oncoprctein was weakly positive in groups II, III and IV. The of EGFR was the highest in the group II, III, follwed by group IV and the expression of PKC was weakly positive in the group II and III. Conclusion: $PLC-{\gamma}1$ mediated signal transduction including ras oncoprotein, EGFR, and PKC play a significant role in mucosal regeneration after irradiation. $PLC-{\delta}1$ mediated signal transduction might have an important role in mucosal damage after irradiation. Further studies will be necessary to confirm the signal transduction mediating the $PKC-{\delta}1$.