• Composites Research
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• 제29권1호
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• pp.33-39
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• 2016

본 논문에서는 3차원 평직 복합재료의 3-방향 섬유다발의 굴곡각에 따른 다양한 모델링을 구축하고, 제시한 모델에 대하여 등가 물성치를 예측하였다. 3차원 평직복합재료의 단위셀을 정의하고 미시역학 계산결과인 섬유다발 물성치를 사용하여 섬유다발에 굴곡각에 따라 물성치가 변화하도록 요소 물성축을 설정 후 3차원 평직 복합재료의 중시해석을 수행하였다. 계산결과 등가물성치는 참고문헌에 제시된 해석 및 실험값을 비교하여 타당성을 확보하였으며 계산결과 3-방향 섬유다발 굴곡각이 미치는 영향에 대하여 고찰하였다. 또한 초기파손 강도와 파손순서에 대해서도 조사하였다.

• Toxicological Research
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• 제21권1호
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• pp.77-85
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• 2005

Cadmium is an environmental pollutant exposed from contaminated foods or cigarette smoking and known to cause oxidative damage in organs. We investigated the cadmium-induced apoptosis and cell arrest in human breast cancer cells, MCF-7 cells and MDA-MB-231 cells. Obvious apoptotic cell death was shown in CdCl₂ 100 μM treatment for 12 hr, which were determined by DAPI staining and flow cytometric analysis. In cell cycle analysis, MCF-7 cells and MDA-MB-231 cells were arrested in S phase and G2/M phase respectively. These could be explained by the induction of cell cycle inhibitory protein, p21/sup Waf1/Cip1/ and p27/sup Kip1/, expression and reduction of cyclin/Cdk complexes in both cell lines. The decreased expression of cyclin A and Cdk2 in MCF-7 cells and cyclin B1 and Cdc2 in MDA-MB-231 cells were consistent with the flow cytometric observation. p-ERK expression was increased dose-dependent manner in both cell lines. It suggests that ERK MAPK pathway are involved in cadmium-induced cell cycle arrest and apoptosis. Moreover, cotreatment of zinc (100 μM, 12 hr) recovered the cadmium-induced cell arrest in both cells, which shows cadmium-induced oxidative stress mediates apoptosis and cell cycle arrest in human breast cancer cells.

• 동의생리병리학회지
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• 제16권4호
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• pp.693-700
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• 2002

SCRT (Sochungyong-tang) has been used for immune disease in human. The purpose of this study was effect of Helper T cell, major regulator of immune system. Spleen cell from 8 week BALB/c mice were cultured in SCRT containing medium without activation for 48 h. The MTS assay and flow cytometry revealed that SCRT treated Iympocyte were non-effect in percentage of CD4+ T cell. Subsequently CD4+ T cell were isolated and cultured in SCRT containing medium. SCRT were non-effective on CD4+ T cell without any involvement of APC. In order to evaluate the direct effect of SCRT on Helper T cell, CD4+ T cell isolated after 48 h of culture in SCRT containing medium and activated with and without anti-CD3/anti-CD28 activation for 48 h. A lower level of CD69 was observed in SCRT treated cells in flow cytometry analysis. Subsequently Using RT-PCR analysis the expression of mRNA for IL-2, INF-γ are upregulated and, IL-4 is downregulated in CD4 T cell. The result suggests that SCRT makes Th1 significantly increased and Th2 relatively inhibited. The results suggest that SCRT potentiate Th1 cell and decrease Th2 development at the same time, which is believed to be bemeficial for IgE-mediated responses.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.3057-3060
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• 2015

Background: Cytological examination of pleural effusions is very important in the diagnosis of malignant lesions. Thoracentesis is the first investigation to be performed in a patient with pleural effusion. In this study, we aimed to compare traditional with cell block methods for diagnosis of lung disease accompanied by pleural effusion. Materials and Methods: A total of 194 patients with exudative pleural effusions were included. Ten mililiters of fresh pleural fluid were obtained by thoracentesis from all patients in the initial evaluation. The samples gathered were divided to two equal parts, one for conventional cytological analysis and the other for analysis with the cell block technique. In cytology, using conventional diagnostic criteria cases were divided into 3 categories, benign, malignant and undetermined. The cell block sections were evaluated for the presence of single tumor cells, papillary or acinar patterns and staining with mucicarmine. In the cell block examination, in cases with sufficient cell counts histopathological diagnosis was performed. Results: Of the total undergoing conventional cytological analyses, 154 (79.4%)were reported as benign, 33 (17%) as malignant and 7 (3.6%) as suspicious of malignancy. With the cell block method the results were 147 (75.8%) benign, 12 (6.2%) metastatic, 4 (2.1%) squamous cell carcinoma, 18 (9.3%) adenocarcinoma, 5 (2.6%) large cell carcinoma, 2 (1%) mesothelioma, 3 (1.5%) small cell carcinoma, and 3 (1.5%) lymphoma. Conclusions: Our study confirmed that the cell block method increases the diagnostic yield with exudative pleural effusions accompanying lung cancer.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권5호
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• pp.287-293
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• 2009

Cell survival is the result of a balance between programmed cell death and cellular proliferation. Cell membrane receptors and their associated signal transducing proteins control these processes. Of the numerous receptors and signaling proteins, epidermal growth factor receptor (EGFR) is one of the most important receptors involved in signaling pathways implicated in the proliferation and survival of cancer cells. EGFR is often highly expressed in human tumors including oral squamous cell carcinomas, and there is increasing evidence that high expression of EGFR is correlated with poor clinical outcome of common human cancers. Therefore, we examined the antiproliferative activity of gefitinib, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in head and neck cancer cell lines. SCC-9, KB cells were cultured and growth inhibition activity of gefitinib was measured with MTT assay. To study influence of gefitinib in cell cycle, we performed cell cycle analysis with flow cytometry. Western blot was done to elucidate the expression of EGFR in cell lines and phosphorylation of EGFR and downstream kinase protein, Erk and Akt. Significant growth inhibition was observed in SCC-9 cells in contrast with KB cells. Also, flow cytometric analysis showed G1 phase arrest only in SCC-9 cells. In Western blot analysis for investigation of EGFR expression and downstream molecule phosphorylation, gefitinib suppressed phosphorylation of EGFR and downstream protein kinase Erk, Akt in SCC-9. However, in EGFR positive KB cells, weak expression of active form of Erk and Akt and no inhibitory activity of phosphorylation in Erk and Akt was observed. The antiproliferative activity of gefitinib was not correlated with EGFR expression and some possibility of phosphorylation of Erk and Akt as a predictive factor of gefitinib response was emerged. Further investigations on more reliable predictive factor indicating gefitinib response are awaited to be useful gefitinib treatment in head and neck cancer patients.

• Biomolecules & Therapeutics
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• 제3권2호
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• pp.122-131
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• 1995

Five human cancer cell lines (HeLa S3, Hep 3B, KATO III, Hs 683, HeLa MR) and one human normal cell line (WI-38) were examined cell viability, northern blot analysis, western blot analysis, and in situ hybridization for the expression $O_{6}$ -methylguanine-DNAmethyltransferase (MGMT), which can repair $O_{6}$ -methylguanine produced in DNA by alkylating agents. In cell viability test, the lethal sensitivities of each strain against anti-tumor drug N,N-bis(2-chloroethyl)- N-nitrosourea (BCNU) were counted, and both BCNU treated and untreated cell extracts were examined for their MGMT inducibility by RNA dot blot analysis. Cell lines did not show MGMT induction by BCNU pretreatment. Tlle MGMT activity was assayed by measuring the $^3$H radioactivity transferred from the substrate DNA containing [methyl-$^3$H)-O$_{6}$ -methylguanine to acceptor molecules in the cell extracts. Extracts from the majority of tumor strains and normal cells contained substantial MGMT activity of varying degree, while the known Mer$^{[-10]}$ cell (lacked or severely depleted in MGMT activity) Hela MR, and Hs 683 (proved to be Mer$^{[-10]}$ ) were much more sensitive to BCNU than the rest of tumor strains, as measured by cell viability test. Overall results above, KATO III showed the highest expression level of MGMT among the strains examined. Furthermore, with all the tumor and normal strains tested, a good correlation was observed between MGMT expression and cellular resistance to BCNU. The varying levels of expression of MGMT in human cancer cells found in this study should provide a molecular basis for MGMT expression among tumor strains from different tissue origin, the information of antitumor agents selection for chemotherapy of cancers.

• Journal of Electrochemical Science and Technology
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• 제7권3호
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• pp.234-240
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• 2016

The effect of initial electrolyte loading (IEL) on cell performance in a coin-type molten carbonate fuel cell (MCFC) was investigated in this work. Since the material of MCFC depends on the manufacturer, optimisation requires experimental investigation. In total, four IEL values, 1.5, 2.0, 3.0, and 4.0 g, were used, corresponding to a pore filling ratio (PFR) of 38, 51, 77, and 102%, respectively. The cell performance with respect to the PFR was analysed via steady-state polarisation, step-chronopotentiomtery, and impedance methods. The electrochemical analyses revealed that internal resistance and overpotential of the cell decreased with increasing PFR, and a large overpotential was observed when the PFR was 102%, probably due to the flooding phenomenon. After operation, cross-section of the cell was analysed via surface analysis of SEM and EDS methods, and the remaining electrolyte was estimated by dissolution of the cell in 10 wt% acetic acid. A linear relationship between IEL and the weight reduction ratio by dissolution was obtained. Thus, the remaining amount of electrolyte could be measured after operation. The results of SEM and EDS showed that a PFR of 38 and 102% showed a lack and flooding of electrolytes at the cell, respectively, which led to a large overpotential. This work reports that MCFC performance is allowed only in the narrow range of PFR.

• 대한한방부인과학회지
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• 제19권2호
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• pp.199-213
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• 2006

Purpose : This study was aimed to investigate the inhibitory effect of Sparganii Rhizoma on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : This study was evaluated the number of death cells treated with indicated concentration of Sparganii Rhizoma and investigated cell death rate by MTS assay. Furthermore, fluorescence-activated cell sorter analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results :1) The inhibitory effect on the growth of uterine leiomyoma cell treated with Sparganii Rhizoma was increased in a dose dependent manner. 2) As the result of FACS analysis, subG1 phase incrase was observed 23.49% inuterine leiomyoma cell treated with Sparganii Rhizoma at $500\;{\mu}g/ml$ compared to control.. 3) The gene expression of p53, p21 related cell apoptosis was increased according to increasing concentration but p27 was none exchanged. 4) The expression of cyclin A, D and E was decreased in a concentration proportional and then the dephosphorylation of pRb was increased. 5) The character of apoptosis, DNA fragmentation was significantly observed according to increasing concentration. 6) The expression of pro-caspase3 were decreased dependent on treatment concentration and activated PARP took place. Conclusion : The inhibitory effect of Sparganii Rhizoma on the proliferation of human uterine leiomyoma cells was observed with apoptosis and cell cycle arrest. These data suggest that Sparganii Rhizoma might be candidate of medical therapy for uterine leiomyoma.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.291-303
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• 2003

This work is proposed an alternative identification method of outlying cell which is one of important issues in categorical data analysis. One finds that there is a strong relationship between the location of an outlying cell and the corresponding parameter estimates of the well-fitted log-linear model. Among parameters of log-linear model, an outlying cell is affected by interaction terms rather than main effect terms. Hence one could identify an outlying cell by investigating of parameter estimates in an appropriate log-linear model.

• Journal of Nutrition and Health
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• 제31권4호
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• pp.799-808
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• 1998

To investigate the antitumor activity of mugwort (Artemisia princeps Pampan), petroleum ether extract of mugwork was partially purified by a silica gel chromatography. Among several fractions, the fraction which was obtained under the elution with acetone, showed potent cytotoxicity against mouse leukemia cell line(Ll210), human colon cancer cell line (HCT-48) and human hepatoma cell line (Hep G2) , but was less effective with normal cell line(mouse embryo cell). Acetone fraction appeared to be glycolipid by Benedict test and the major fatty acids of the lipid were C16 ; 0 , C 18: 3by GC/MS analysis.