• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3779-3783
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• 2015

Dietary prevention has been known to reduce breast cancer risk. Sesamin is one of the major components in sesame seeds and has been widely studied and proven to have anti-proliferation and anti-angiogenic effects on cancer cells. In this study, the influence of sesamin was tested in the human breast cancer MCF-7 cell line for cell viability (MTT assay) and cell cycling (flow cytometry). Results showed that sesamin dose-dependently (1, 10 and $50{\mu}M$) reduced the cell viability and increased LDH release and apoptosis (TUNEL assay). In addition, there was a significant increase of sub-G1 phase arrest in the cell cycle after sesamin treatment. Furthermore, sesamin increased the expression of apoptotic markers of Bax, caspase-3, and cell cycle control proteins, p53 and checkpoint kinase 2. Taken together, these results suggested that sesamin might be used as a dietary supplement f or prevention of breast cancer by modulating apoptotic signal pathways and inhibiting tumor cell growth.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6429-6433
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• 2012

To explore a possible new treatment for human ovarian cancer, we studied the effects of sodium valproate on the growth of the HO8910 human cell line. HO8910 cells were cultured in vitro and treated with different concentrations of sodium valproate. Cell proliferation, cell cycling, and apoptosis were measured by flow cytometry, cell morphology under a microscope, and expression levels of WWOX and P27 by Western blotting and RT-PCR. Tumor xenografts were established to determine in vivo effects of sodium valproate. Our results showed that cell proliferation was decreased with increasing concentration of sodium valproate, with features of cytoplasmic retraction and floating cells. Moreover, cell cycle analysis revealed a higher apoptosis rate and $G_0/G_1$ phase in the sodium valproate experimental group than in the control group. In addition, protein expression levels of WWOX and P27 were elevated. Importantly, sodium valproate decreased in vivo xenograft tumor burden and up-regulated WWOX and P27 expression in nude mice. In conclusion, sodium valproate might play a role in inhibition and control of ovarian cancer cell line HO8910 by inhibiting cell proliferation, interfering with the cell cycle and promoting apoptosis, so that it may be effective in the clinical treatment of ovarian cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3803-3807
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• 2012

Prohibitin (PHB), an evolutionarily-conserved protein, has been found to be over-expressed in gastric cancer and be closely related with tumor malignancy. In this study, to investigate the relationship between PHB expression and cell apoptosis in the BGC823 gastric cancer cell line, low and high expression PHB in BGC823 cells was accomplished using RNA interference technology and gene transfer techniques. Cell proliferation, cell cycling, apoptosis, Bax, Bcl-2 and Cyt.c protein expression and the activation of Caspase-3,9 were assessed after 48h. Over-expression of PHB gene in BGC823 cells resulted in slow cell growth, cell arrest in G2 phase, and an increased apoptosis ratio while the opposite was found for PHB under-expressing cells. In PHB over-expressing cells, the expression of Bax gene was increased, the expression of Bcl-2 was decreased, the activation level of Caspase-3, 9 was increased, but the activation level of Caspase-8 demonstrated no change. These results indicate that PHB induced apoptosis through the mitochondrial pathway.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.3
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• pp.223-227
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• 2007

The effect of Eu contents on the ferroelectric properties of $Bi_{4-x}Eu_xTi_3 O_{12}$ (BET) thin films has been investigated. Bismuth Europium titanate thin films with a Eu contents were prepared on the $Pt/Ti/SiO_2/Si$ substrate by metal-organic decomposition technique. The structure and the morphology of the films were analyzed using X-ray diffraction (XRD) and field emission scanning microscopy (FE-SEM), respectively. From the XRD analysis, it was found that BET thin films have polycrystalline structure, and the layered-perovskite phase is obtained when the Eu contents exceeds 0.2 (x > 0.2). Also, the ferroelectric characteristics of the BET thin films were found to be dependent on the Eu content. Particularly, the BET films doped with x = 0.75 show better ferroelectric properties (remanent polarization 2Pr = 60.99 C/$cm^2$ and only a little polarization fatigue up to $3.5{\times}10^9$ bipolar switching cycling) than those doped with other Eu contents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.245-248
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• 2003

Randomly oriented ferroelectric cerium-substituted $Bi_4Ti_3O_{12}$ thin films have been prepared by using metal-organic decomposition method. The layered perovskite structure was investigated using annealing for 1 h in the temperature range from $550\;{\sim}\;750\;^{\circ}C$. The structure and morphology of the films were characterized using X-ray diffraction and scanning electron microscopy The $Bi_{3.4}Ce_{0.6}Ti_3O_{12}$ (BCeT) thin films showed a perovskite phase and dense microstructure. The grain size of the BCeT films increasedwith increasing annealing temperature. The hysteresis loops of the films were well defined at temperatures above $600\;^{\circ}C$. The 200-nm-thick BCeT thin films annealed at $650\;^{\circ}C$ showed a large remanent polarization (2Pr) of 59.3 ${\mu}C/cm^2$ at an applied voltage of 10 V. The BCeT thin films showed good fatigue endurance up to $5\;{\times}\;10^9$ bipolar cycling at 5 V and 100 kHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.541-544
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• 2001

Orthorhombic $LiMnO_2$ was synthesized by solid-state reaction using $LiOH{\cdot}H_{2}O$ and $Mn_{2}O_{3}$ as starting material. Its electrochemical properties as cathode in lithium batteries were examined. X-ray diiffraction revealed that the $LiMnO_2$ compound showed a well-defined orthorhombic phase of a space group with Pmnm. The capacity of $LiMnO_2$ agreed well with its specific surface area and grinding treatment was effective in improving cycling performance. For lithium polymer battery applications. the $LiMnO_2$ cell was characterized electrochemically by charge-discharge experiments. And the relationship between the characteristics of powder and electrochemical properties was studied in this research. A maximum discharge capacity of $160-170mAhg^{-1}$ for $LiMnO_2/Li$ cell was achieved.

• 한국전기화학회:학술대회논문집
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• 2002.11a
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• pp.57-65
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• 2002

The presence of tetragonal phase at the surface of $LiMn_2O_4$ pinicle due to a Jahn-Teller offset was previously reported to be one of the causes for capacity fading observed during cycling of $Li//Li_xMn_2O_4$ in 4V range. Further, it is reported that a Jahn-Teller effect in 4V range may be suppressed by substitution of Mn ions with Li ions or other transition metal ions. However, the direct evidence of the suppression of a Jahn-Teller effect in 4V range by substitution of Mn ions with other metal ions has not been reported. The dissolution and formation of surface film at the surface of $LiMn_2O_4$ electrodes also reportedly affect the capacity fading or rate capability. This study reports on the evidence of the onset and suppression of a Jahn-Teller effect in 4V range and the dissolution and formation of surface film at the surface of $LiMn_2O_4$ thin film electrodes using in situ bending beam method (BBM) in situ electrochemical quartz crystal microbalance (EQCM).

• Transactions of Materials Processing
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• v.26 no.6
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• pp.356-364
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• 2017

In this study, submerged arc cladded Fe-Cr-Ni-Mo-CuWNbV-C stainless steels containing various Cr contents between 11.2 wt.% and 16.7 wt.% were prepared with fixed C content at about 0.14 wt.%. Using these alloys, changes in microstructure, tensile property, and thermal fatigue property were investigated. Phase fraction of delta-ferrite was increased gradually with increasing Cr content. However, tensile strength, hardness, and thermal fatigue resistance appeared to be decreased. When the microstructure of delta-ferrite was observed, it was revealed that the mesh structure retained up to about 15% Cr content. Although thermal fatigue resistance was almost the same for Cr contents between 11.0 and 14.5 wt.%, it was significantly decreased at higher Cr contents. This was evident from mean value of crack lengths of 10 largest ones. Evaluation of thermal fatigue resistance on alloys with various Cr contents revealed the following important results. First, the reproducibility of ranking test was excellent regardless of the number of cycles. Second, thermal fatigue resistance was increased in proportion to true tensile fracture strength values of overlay materials. Finally, the number of thermal fatigue cracks per unit length was increased with increasing true tensile fracture strength.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.604-609
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• 2002

In development of an advanced bicycle simulator, the investigation of the interactions between bicycle and rider during cycling is paramount important because bicycle is a two-wheeled human-powered vehicle. Tn this work, the tilt stability. among various interactions, of bicycling is investigated experimentally, In the experiments, the tilt angles of the bicycle, riders body and head are measured, as the riding p;1th and the speed are varied. Subjects are asked to ride along four typical paths on rigid flat ground : the straight, C-curved, S-curved and circle paths. The results from extensive experiments with different subjects can be summarized as : 1) The tilt angles of bicycle and rider are almost out of phase during pedaling along the straight path. 2) The bicycle tilt angle is nearly proportional to the square of bicycle speed for the straight and curved paths, and to the curvature for the curved paths. The head tilt angle is the biggest and the body tilt angle is the smallest for the straight path, but the tendency is reversed for the C-curved path. During the curve maneuvering, the rider's head tends to tilt by less than 40% of the bicycle tilt angle.

• Journal of the Korean Ceramic Society
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• v.50 no.5
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• pp.348-352
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• 2013

The evaluation of plasma resistance and the characteristics of yttria ceramics fabricated by calcination yttria as a starting material without dopants under an oxidation atmosphere was investigated. Regardless of the starting materials, as-received, and calcined yttria powder, XRD patterns showed that all samples have $Y_2O_3$ phase. The three cycling process inhibited a large grain, which occurs frequently during the yttria sintering, and a high density ceramic with a homogeneous grain size was obtained. The grain size of the sintered ceramic was affected by the starting powders. The smaller the grain size, the larger were the Young's modulus and KIC. Compared to $Al_2O_3$ and $ZrO_2$ ceramics, yttria ceramics showed a 3 times larger plasma resistance and a 1.4~2.2 times lower weight loss during the plasma etching test, respectively.