• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1812-1820
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• 2017

This paper analyzes a symmetric active cell balancer for a battery management system. The considered cell balancer uses a forward converter in which the circuit structure is symmetric. This cell-balancing method uses fewer switches and is simpler than the previously proposed active cell-balancing circuits. Active power switches of this cell-balancing circuit operate simultaneously with the same pulse width modulation signals. Therefore, this cell-balancing circuit requires less time to be balanced than a previous bidirectional-forward-converter-based cell balancer. This paper analyzes the operational principles and modes of this cell balancer with computer-based circuit simulation results as well as experimental results in which each unbalanced cell is equalized with this cell balancer. The maximum power transfer efficiency of the investigated cell balancer was 87.5% from the experimental results. In addition to the experimental and analytical results, this paper presents the performance of this symmetric active cell-balancing method.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4335-4339
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• 2012

Background: Whether sirolimus is useful in the prevention of non-melanoma skin cancer (NMSC) remains unclear and we therefore performed this meta-analysis of randomized controlled trials to test the hypothesis that Sirolimus-based immunosuppression is associated with a decrease in NMSC. Methods: The main outcomes were NMSC, squamous-cell carcinoma and basal-cell carcinoma. The pooled risk ratio (RR) with its 95% confidence interval (95%CI) were used to assess the effects. Results: 5 randomized trials involving a total of 1499 patients receiving kidney transplantation were included. Patients undergoing Sirolimus-based immunosuppression had much lower risk of NMSC (RR = 0.49, 95%CI 0.32-0.76, P = 0.001). Subgroup analyses by tumor type showed that Sirolimus-based immunosuppression significantly decreased risk of both squamous-cell carcinoma (RR = 0.58, 95%CI 0.43-0.78, P < 0.001) and basal-cell carcinoma (RR = 0.56, 95%CI 0.37-0.85, P = 0.006). The quality of evidence was high for NMSC, and moderate for squamous-cell carcinoma and basal-cell carcinoma. No evidence of publication bias was observed. Conclusion: High quality evidence suggests that Sirolimus-based immunosuppression decreases risk of non-melanoma skin cancer, and Sirolimus has an antitumoral effect among kidney-transplant recipients.

• The Journal of Korean Medicine
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• v.36 no.4
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• pp.19-34
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• 2015

Objectives: This study was performed to investigate the anti-tumor effect of O. japonicus extracts on intrahepatic cholangiocarcinoma cell line SNU-1079. Methods: Cholangiocarcinoma SNU-1079 cells were treated with various concentrations of O. japonicus DW and EtOH extracts ($0-300{\mu}g/ml$) for 24, 48 or 72 h. Cell viability was evaluated through a PMS/MTS assay, and the apoptosis rate was examined through ELISA assay and flow cytometry analysis. The mRNA expression of apoptosis- and cell cycle progression-related genes (Bcl-2, Mcl-1, Bax, Survivin, Cyclin D1, and p21) was evaluated using real-time PCR, and the caspase activity was examined using immunoblot analysis. Results: O. japonicus extracts inhibited cell proliferation and increased apoptosis rate in both ELISA assay and flow cytometry analysis. O. japonicus extracts decreased Bcl-2, Mcl-1, Survivin, and Cyclin D1 mRNA expression and increased Bax mRNA level. O. japonicus extracts also increased Caspase-3 activation. Overall, O. japonicus DW extracts were more effective than EtOH extracts. Conclusions: O. japonicus inhibited cell proliferation and induced apoptosis in SNU-1079 cells via mitochondria -mediated intrinsic pathway, which leads to Caspase-3 activation. The results indicate that O. japonicus is a potential therapeutic herb with anti-tumor effect against intrahepatic cholangiocarcinoma.

• New & Renewable Energy
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• v.7 no.1
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• pp.36-44
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• 2011

Technology is developed from the efficient interaction with other technology files while building up its own research field. This study analyzes the structure of solar cell research area and describes its paths of the technology development in terms of interdisciplinary diversity using the Co-Classification method during 1979-2009. As a results, 1,380 studies are determined as the interdisciplinary among the 2,605 studies. It shows that 52.98% of the solar cell researches have interdisciplinary relationships with two or more research fields. In addition, we show that the research area of solar cell technology is composed by Material Science, Multidisciplinary and Energy & Fuel, Physics, Applied, Chemistry, Physical from the Co-Classification matrix and network analysis. It means the complexity of the technological knowledge production increased with the concept of interdisciplinary. The results can be used for the planning of the efficient solar cell technology development.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.1
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• pp.23-37
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• 1997

In this paper, performance analysis of video traffic shaper for Motion Picture Experts Group (MPEG) video traffic in on ATM network are investigated. Traffic shaping for MPEG video traffic is proposed as a traffic control function in ATM networks. The proposed shaper smoothes video traffics by controling the output rate of the buffer, which is placed in an MPEG source, according to I,B,P frame sequences of MPEG. In performance analysis of an video traffic shaper, a periodic botch arrival model is suggested to describe cell streams in a frame of MPEG video traffic. The queueing model which has periodic independent botch arrival and periodic deterministic service time is used to obtain the cell loss ratio, the mean cell delay, and the measure of smoothing effect. Simulation results are used to validate this queueing model. The cell loss performance of ATM multiplexer is measured by simulation study with real MPEG-1 data. From the viewpoint of traffic load, the cell loss ratio is observed to be considerably high, which is considered to result from the burstiness of MPEG video traffic. As a result, it is shown that the shaping decreases cell loss ratio of multiplexer. The results of this paper can be employed to establish a basic guideline in the implementation of a traffic control scheme and the design of ATM multiplexer for MPEG video traffic.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.52-55
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• 2002

Flow cytometric techniques were used to investigate cell size, protein content and cell cycle behavior of recombinant Saccharomyces cerevisiae strains producing human lysozyme (HLZ). Two different signal sequences, the native yeast $MF\alpha1$ signal sequence and the rat $\alpha-amylase$ signal sequence, were used for secretion of HLZ. The strain containing the rat $\alpha-amylase$ signal sequence showed a higher level of internal lysozyme and lower specific growth rates. Flow cytometric analysis of the total protein content and cell size showed the strain harboring the native yeast signal sequence had a higher total protein content than the strain containing the rat $\alpha-amylase$ signal sequence. Cell cycle analysis indicated that the two lysozyme producing recombinant strains had an increased number of cells in the $G_2+M$ phase of the yeast cell cycle compared with the host strain SEY2102.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.1
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• pp.11-18
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• 2015

Objectives: The goal of this study was to determine the correlation of clinicopathological factors and the up-regulation of vascular endothelial growth factor (VEGF) expression in oral squamous cell carcinoma. Materials and Methods: Immunohistochemical staining of VEGF and quantitative real-time polymerase chain reaction (RT-PCR) of VEGF mRNA were performed in 20 specimens from 20 patients with oral squamous cell carcinoma and another 20 specimens from 20 patients with carcinoma in situ as a controlled group. Results: The results were as follows: 1) In immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, high-level staining of VEGF was observed. Significant correlation was observed between immunohistochemical VEGF expression and histologic differentiation, tumor size of specimens (Pearson correlation analysis, significance r>0.6, P<0.05). 2) In VEGF quantitative RT-PCR analysis, progressive cancer showed more VEGF expression than carcinoma in situ. Paired-samples analysis determined the difference of VEGF mRNA expression level between cancer tissue and carcinoma in situ tissue, between T1 and T2-4 (Student's t-test, P<0.05). Conclusion: These findings suggest that up-regulation of VEGF may play a role in the angiogenesis and progression of oral squamous cell carcinoma.

• Journal of the Korean Society of Visualization
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• v.21 no.3
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• pp.49-56
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• 2023

The Polymer electrolyte membrane fuel cell (PEMFC) operates at ambient temperature as a low-temperature fuel cell. During its operation, voltage losses arise due to factors such as operating conditions and material properties, effecting its performance. Computational simulations of fuel cells can be categorized into 1D simulation and CFD, chosen based on their specific application purposes. In this study, we carried out an analysis validation using 1D geometry and compared its performance with the results from 2D geometry analysis. CFD allows for the representation of pressure, velocity distribution, and fuel mass fraction according to the geometry, enabling the analysis of current density. However, the 1D simulation, simplifying governing equations to reduce time cost, failed to accurately account for fuel distribution and changes in fuel concentration due to fuel cell operations. As a result, it showed unrealistic results in the cell voltage region dominated by concentration loss compared to CFD.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.81-88
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• 1998

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.3
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• pp.1-13
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• 2011

Objectives: This study was designed to investigate the analysis of apoptosis by Scirpi Tuber in Hela cell and MCF-7 cell. Methods: For cytotoxic effect of Scirpi Tuber extract, Scirpi Tuber extract were cultured on NIH3T3 cell in vitro. After treatment with various concentration of Scirpi Tuber, cell growth was evaluated in Hela cell and MCF-7 cell. Hoechst 33342 staining was performed to estimate DNA fragment effect of Scirpi Tuber on the apoptosis in Hela cell and MCF-7 cell. Annexin V/PI apoptosis assay was used to estimate the effects of Scirpi Tuber on the early apoptosis in Hela cell MCF-7 cell. All the stained cells were analyzed by a FACS. RT-PCR was used to estimate the apoptosis gene expression effect of Scirpi Tuber extract on Hela cell and MCF-7 cell. Results: Cytotoxic effect of Scirpi Tuber extract was not found on per NIH3T3 cell. The viability of Hela cell was significantly decreased Scirpi Tuber (500, $1000{\mu}g/m\ell$) in Hela cell 1day, 3day and 5days after treatment (p<0.01). The viability of MCF-7 cell was significantly decresed Scirpi Tuber ($1000{\mu}g/m\ell$) in MCF-7 cell (p<0.01), Scirpi Tuber ($500{\mu}g/m\ell$) in MCF-7 cell only 3days after treatment (p<0.01). In RT-PCR analysis, after treatment of $100{\mu}g/m\ell$ of ACR extract, BCL-2 were decreased and BAX, caspase-3 were increased both in Hela cell and MCF-7 cell. DNA fragmentation was observed the Scirpi Tuber on Hela cell and MCF-7 cell. As time goes on DNA fragmentation incresed. In Annexin V/PI apoptosis assay, after treatment of $1mg/m\ell$ of Scirpi Tuber, the early apoptotic cell increased both in Hela cell and MCF-7 cell. As time goes on apoptotic cell increased. Conclusion: Scirpi Tuber appears to have considerable activity on the apoptosis in Hela cell and MCF-7 cell.