• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.38-46
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• 2011

In order to simulate the ignition-gas injection in the interior ballistics, a two-dimensional analytic code for two-phase flows has been developed. The Eulerian-Lagrangian approach and the low-dissipation simple high-resolution upwind scheme(LSHUS) have been adopted in the numerical code for the propellant combustion of the gun propelling charges. The ghost-cell extrapolation method has been used for the moving boundary in the chamber with the projectile movement. The calculation results of the developed code have been compared and verified through those of the dimensionless IBHVG2 code and the previous one-dimensional code. In comparison with the two-phase flows according to the drag models, the numerical analysis of the muzzle velocity has been affected by the drag model.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.797-802
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• 2014

We screened a small molecular library that was designed and independently synthesized in vitro and found a new drug (MY-03-01) that is active against ovarian cancer. We established that MY-03-01 effectively inhibited SKOV-3 cell survival in a dose-dependent manner, based on cell viability rates, and that it not only induced SKOV-3 apoptosis by itself, but also did so synergistically with paclitaxel. Secondly, when MY-03-01 was applied at $40{\mu}M$, its hemolytic activity was less than 10%, compared with the control, and there was almost no damage to nor mal cells at this concentration. In addition, we used DAPI staining and flow cytometry to show that MY-03-01 could significantly induce apoptosis of SKOV-3 cells. Finally, we found that MY-03-01 likely induced SKOV-3 apoptosis by activating caspase3 and caspase9 through the mitochondrial pathway.

• The KSFM Journal of Fluid Machinery
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• v.17 no.2
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• pp.48-53
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• 2014

A low-noise regenerative blower is developed for fuel cell application by combining the FANDAS-Regen code and design optimization algorithm under several performance constraints for flow capacity, static pressure, efficiency and power consumption. The optimized blower design model is manufactured with some impeller modification based on low noise design concept and tested by using aerodynamic performance chamber facility and narrow-band noise measurement apparatus. The measured results of the optimized blower satisfy the performance requirements and are also compared favorably with the FANDAS-Regen prediction results within a few percent relative error. Furthermore, the present study shows the remarkable noise reduction by 26 dBA can be achieved through design optimization and low noise design concept.

• Nuclear Engineering and Technology
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• v.16 no.1
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• pp.29-35
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• 1984

Filtration efficiency tests were conducted on a fiberglass mat filter with DOP aerosol having a diameter from 0.l${\mu}{\textrm}{m}$ to 0.45${\mu}{\textrm}{m}$ in the face velocity range of 1cm/sec to 10cm/sec. Filtration of submicron particles by a fibrous filter is characterized by a face velocity. The size of DOP aerosol which has a minimum removal efficiency decreases with increasing the velocity. A numerical solution of the diffusion equation is obtained for a fiberglass mat filter by using "Kuwabara's cell model" for the flow field and Von Mises Transformation for the actual flow around a fiberglass. The present theoretical results agree quite well with the experimentals for fiberglass mat. This result could be contributed to predict the removal efficiency on an air filter and to optimize the operating condition of an air purification system with a filter. a filter.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2070-2075
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• 2004

Performance of a solid oxide fuel cell (SOFC) can be enhanced by converting thermal energy of its high temperature exhaust gas to mechanical power using a micro gas turbine (MGT). A MGT plays also an important role to pressurize and warm up inlet gas streams of the SOFC. In this study, the influence of performance characteristics of the tubular SOFC on the hybrid power system is discussed. For this purpose, detailed heat and mass transfer with reforming and electrochemical reactions in the SOFC are mathematically modeled, and their results are reflected to the performance analysis. The analysis target is 220kWe SOFC/MGT hybrid system based on the tubular SOFC developed by Siemens-Westinghouse. Special attention is paid to the ohmic losses in the tubular SOFC counting not only current flow in radial direction, but also current flow in circumferential direction through the anode and cathode.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.273-276
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• 2014

Ellagic acid has been shown to inhibit tumor cell growth. However, the underlying molecular mechanisms remain elusive. In this study, our aim was to investigate whether ellagic acid inhibits the proliferation of MCF-7 human breast cancer cells via regulation of the TGF-${\beta}$/Smad3 signaling pathway. MCF-7 breast cancer cells were transfected with pEGFP-C3 or pEGFP-C3/Smad3 plasmids, and treated with ellagic acid alone or in combination with SIS3, a specific inhibitor of Smad3 phosphorylation. Cell proliferation was assessed by MTT assay and the cell cycle was detected by flow cytometry. Moreover, gene expression was detected by RT-PCR, real-time PCR and Western blot analysis. The MTT assay showed that SIS3 attenuated the inhibitory activity of ellagic acid on the proliferation of MCF-7 cells. Flow cytometry revealed that ellagic acid induced G0/G1 cell cycle arrest which was mitigated by SIS3. Moreover, SIS3 reversed the effects of ellagic acid on the expression of downstream targets of the TGF-${\beta}$/Smad3 pathway. In conclusion, ellagic acid leads to decreased phosphorylation of RB proteins mainly through modulation of the TGF-${\beta}$/Smad3 pathway, and thereby inhibits the proliferation of MCF-7 breast cancer cells.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.1
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• pp.59-65
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• 2012

A study on the electrical characteristic analysis of solar cell diodes under experimental conditions of varying temperature and frequency has been conducted. From the current-voltage (I-V) measurements, at the room temperature, we obtained the ideality factor (n) for Space Charge Region (SCR) and Quasi-Neutral Region (QNR) of 3.02 and 1.76, respectively. Characteristics showed that the value of n (at SCR) decreases with rising temperature and n (at QNR) increases with the same conditions. These are due to not only the sharply increased SCR current flow but the activated carrier recombination in the bulk region caused by defects such as contamination, dangling bonds. In addition, from the I-V measurements implemented to confirm the junction uniformity of cells, the average current dispersion was 40.87% and 10.59% at the region of SCR and QNR, respectively. These phenomena were caused by the pyramidal textured junction structure formed to improve the light absorption on the device's front surface, and these affect to the total diode current flow. These defect and textured junction structure will be causes that solar cell diodes have non-ideal electrical characteristics compared with general p-n junction diodes. Also, through the capacitance-voltage (C-V) measurements under the frequency of 180 kHz, we confirmed that the value of built-in potential is 0.63 V.

• Journal of Oriental Neuropsychiatry
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• v.10 no.2
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• pp.47-57
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• 1999

Recently, essential oils are used for aromatherapy. Most essential oils are said to be anti-bacterial; some may be anti-viral or anti-fungal. I investigated the effects of peppermint pure essential oil on the heat shock-induced apoptosis in human astrocyte cell line CCF-STTGI. In previous studies, heat shock has been reported to induce the apoptosis or programmed cell death through the activation of caspase-3. We studied the heat shock-induced apoptosis through flow cytometry, DNA electrophoresis, and giemsa staining. Interestingly, these events were inhibited by pretreatment of peppermint pure essential oils in CCF-STTGl cells. Peppermint oil also inhibited the heat shock-induced apoptosis in primary cultured rat astrocytes. In addition, this Peppermint essential oil inhibited the heat shock-induced activation of caspase-3. These results suggest that peppermint pure essential oils may modulate the apoptosis through the activation of the interleukin-I -converting enzyme-like protease.

• Biomedical Science Letters
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• v.26 no.4
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• pp.336-343
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• 2020

The present study was carried out to investigate the possibility that bispidinone derivative makes anticancer drug availability to human cervical carcinoma cell. The B8 has the lowest IC50 value among B8, B9 and B10 which are bispidinone analogue with bromide. According to cytotoxic test through WST-8 assay, B8 shows the most magnificent cytotoxicity effectiveness with 76 μM of IC50 value. In human cervical carcinoma cell treated with B8, it noticeably controlled cellular multiplication by increase of concentration and time. Furthermore, morphological changes like cellular shrink, disruption and nuclear condensation, feature of apoptosis, are observed. Annexin V-FITC/PI double staining assay test proved that B8 can cause apoptosis. Moreover, after treatment with 76 μM of B8, flow cytometry analysis shows that increase of active oxygen species are induced and membrane potential in mitochondria is decreased. Manifestation of Bcl-2 family and caspase cascades protein provides evidence that B8 induces apoptosis through mitochondria and caspase-related pathway. Taken together, we suggested that B8 reduced membrane potential in mitochondria and induce apoptosis through the pathway depended on mitochondria and caspase.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2683-2688
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• 2016

A salt compound of a curcumin analogue, potassium pentagamavunon-0 (K PGV-0) has been synthesized to improve solubility of pentagamavunon-0 which has been proven to have anti-proliferative effects on several cancer cells. The purpose of this study was to investigate cytotoxic activity and metastasis inhibition by K PGV-0 alone and in combination with achemotherapeutic agent, doxorubicin (dox), in breast cancer cells. Based on MTT assay analysis, K PGV-0 showed cytotoxic activity in T47D and 4T1 cell lines with $IC_{50}$ values of $94.9{\mu}M$ and $49.0{\pm}0.2{\mu}M$, respectively. In general, K PGV-0+dox demonstrated synergistic effects and decreased cell viability up to 84.7% in T47D cells and 62.6% in 4T1 cells. Cell cycle modulation and apoptosis induction were examined by flow cytometry. K PGV-0 and K PGV-0+dox caused cell accumulation in G2/M phase and apoptosis induction. Regarding cancer metastasis, while K PGV-0 alone did not show any inhibition of 4T1 cell migration, K PGV-0+dox exerted inhibition. K PGV-0 and its combination with dox inhibited the activity of MMP-9 which has a pivotal role in extracellular matrix degradation. These results show that a combination of K PGV-0 and doxorubicin inhibits cancer cell growth through cell cycling, apoptosis induction, and inhibition of cell migration and MMP-9 activity. Therefore, K PGV-0 may have potential for development as a co-chemotherapeutic agent.