• 환경생물
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• 제23권1호
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• pp.21-26
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• 2005

Cell response to genotoxic agents is complex and involves the participation of different classes of genes including cell cycle control, DNA repair and apoptosis. In this report, we presented a approach to characterize the cellular functions associated with the altered transcript profiles of MCF-7 exposed to low-dose in vitro gamma-irradiation. We used the method of human 2.4 k cDNA microarrays containing apoptosis, cell cycle, chromatin, repair, stress and chromosome genes to analyze the differential gene expression characterization that were displayed by radiation-exposed cell, human breast carcinoma MCF-7 cell line, such as 4 Gy 4 hr, 8 Gy 4 hr, and 8 Gy 12 hr. Among these genes, 66 were up-regulated and 49 were down-regulated. Specific genes were concomitantly induced in the results. Cyclin dependent kinase 4 (Cdk4) is induced for starting the cell cycle. This regulation is required for a DNA damage­induced G1 arrest. In addition to, an apoptotic pathways gene Bcl-w was concomitantly induced. Mismatch repair protein homologue-l (hMLH1), a necessary component of DNA mismatch protein repair (MMR), in G2-M cell cycle checkpoint arrest. The present study provides new information on the molecular mechanism underlying the cell response to genotoxic stress, with relevance to basic and clinical research.

• 대한금속재료학회지
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• 제47권7호
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• pp.391-396
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• 2009

Tensile, low cycle fatigue, and fatigue crack growth rate tests were conducted at RT and $300^{\circ}C$ for type 304 stainless steel. Tensile was tested under displacement control and low cycle fatigue was tested under strain control. Fatigue crack growth rate test was conducted under load control and crack was measured by DCPD method. Yield strength and elongation decreased at $300^{\circ}C$. Dynamic strain aging was not detected at $300^{\circ}C$. Low cycle fatigue life increased but fatigue strength decreased at $300^{\circ}C$. Fatigue crack growth rate increased at $300^{\circ}C$. Dislocation structures were mixed with cell and planar and did not change with temperature. Grain size did not change but plastic strain increased at $300^{\circ}C$. Strain induced martensite after low cycle fatigue test increased at RT but decreased at $300^{\circ}C$. It was concluded that the increase of low cycle fatigue life at $300^{\circ}C$ was due to the decrease of strain induced martensite at which crack was initiated.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.651-658
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• 2007

This paper presents a new type of fuzzy logic-based power control strategy for fuel cell hybrid electric vehicles designed to improve their fuel economy while maintaining the battery's state of charge. Since fuel cell systems have inherent limitations, such as a slow response time and low fuel efficiency, especially in the low power region, a battery system is typically used to assist them. To maximize the advantages of this hybrid type of configuration, a power distribution control strategy is required for the two power sources: the fuel cell system and the battery system. The required fuel cell power is procured using fuzzy rules based on the vehicle driving status and the battery status. In order to show the validity and effectiveness of the proposed power control strategy, simulations are performed using a mid-size vehicle for three types of standard drive cycle. First, the fuzzy logic-based power control strategy is shown to improves the fuel economy compared with the static power control strategy. Second, the robustness of the proposed power control strategy is verified against several variations in system parameters.

• 대한한방부인과학회지
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• 제21권2호
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• pp.27-37
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• 2008

Purpose: This study was conducted to investigate the effects of Ginseng Radix Alba extract solution on the cell cycle regulation, apoptosis of human uterine myoma cells. Methods: Primary cultured human uterine myoma cells were treated with extract solution of Ginseng Radix Alba concentration of 1, 10 and $100mg/m{\ell}$ for 48 hours. We underwent flow cytometry and western blotting for cell cycle and apoptosis related factors. Results: In flow cytometry, a slight promotion of G1 phase in $1mg/m{\ell}$ group had been observed but, simultaneously a delay of G1 phase in 10 and $100mg/m{\ell}$ groups were also observed. The manifestation of cyclin D1 in Ginseng Radix Alba extract solution medicated group increased compared to the control group. The manifestation of Bax controlling apoptosis increased in terms of concentration but Bcl-2 showed no change. Also VEGF increased in terms of concentration. Conclusion: The present study suggests that Ginseng Radix Alba extract solution treatment in human uterine myoma cells induce the delay of cell cycle and apoptosis. These results suggest that Ginseng Radix Alba will be a promising agent for use in therapeutics agents against human uterine myoma.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1377-1382
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• 2012

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-${\kappa}B$ using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-${\kappa}B$ were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-${\kappa}B$.

• Reproductive and Developmental Biology
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• 제36권4호
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• pp.249-254
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• 2012

This study aimed at investigating whether a porcine follicular fluid (pFF) supplementation positively affects the characteristics of donor cells and the developmental competence of porcine cloned embryos. Ear fibroblast cells (donor cell) from an Massachusetts General Hospital miniature pig were cultured in different culture methods: (1) Dulbecco's modified Eagle's medium (DMEM)+10% FBS (Control); (2) DMEM+0.5% FBS (SS); and (3) DMEM+10% FBS+10% pFF (pFF) for 72 h. In each conditioned medium, the concentrations of 4 amino acids (Thr, Glu, Pro, and Val) in the pFF group were significantly different from those in the control group (p<0.05 or p<0.01). The proliferation of the cells cultured in the SS group was significantly lower than that of the other treatment groups (p<0.01). The population of apoptotic and necrotic cells in the SS group was significantly higher than that of either the control or the pFF group (p<0.01). The number of embryos that cleaved (p<0.05) and developed into blastocysts (p<0.01) in the SS group was significantly lower than that of either the control or the pFF group. Compared to other groups, the blastocysts produced from the donor cells in the pFF group had higher total cells and lower apoptotic cells (p<0.05). It can be concluded that pFF supplementation in the donor cell culture medium positively affects cell death, cell cycle and quality of the cloned blastocyst.

• 드라이브 ㆍ 컨트롤
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• 제16권2호
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• pp.80-90
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• 2019

Fuel cell hybrid electric vehicle is an attractive solution to reduce pollutants, such as noise and carbon dioxide emission. This study presents an approach for energy management and control algorithm based on energetic macroscopic representation for a fuel cell hybrid electric vehicle that is powered by proton exchange membrane fuel cell, battery and supercapacitor. First, the detailed model of the fuel cell hybrid electric vehicle, including fuel cell, battery, supercapacitor, DC-DC converters and powertrain system, are built on the energetic macroscopic representation. Next, the power management strategy was applied to manage the energy among the three power sources. Moreover, the control scheme that was based on back-stepping sliding mode control and inversed-model control techniques were deduced. Simulation tests that used a worldwide harmonized light vehicle test procedure standard driving cycle showed the effectiveness of the proposed control method.

• 한국자동차공학회논문집
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• 제16권2호
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• pp.150-157
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• 2008

The main objective of this paper is to investigate the performance characteristics of a $CO_2$ air conditioning system for fuel cell electric vehicles (FCEV). The present air conditioning system for FCEV uses the electrically driven compressor and electrically controlled expansion valve for $CO_2$ as a working fluid. The experimental work has been done with various operating conditions, which are quite matching the actual vehicle's driving conditions such as different compressor speed and high pressure to identify the characteristics of the system. Experimental results show that the cooling capacity and coefficient of performance (COP) were up to 6.3kW and 2.5, respectively. This paper also deals with the development of optimum high pressure control algorithm for the transcritical $CO_2$ cycle to achieve the maximum COP.

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.611-623
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• 2001

Cyclosporin A is a cyclic polypeptide produced by the metabolism of fungi. It is widely used at present as immunosuppressive treatment following organ transplants. It is also used to deal with autoimmune diseases such as rheumatoid arthritis or type II diabetes. Gingival hyperplasia is one of the most frequent side-effects associated with the prescription of Cyclosporin A. The mechanisms involved in Cyclosporin A induced gingival hyperplasia are not yet clear. In vitro Cyclosporin A promotes proliferation of gingival fibroblasts, that Cyclosporin A act as a mitogen. Its action is based on mitosis of gingival fibroblasts regulated by cell cycle regulatory proteins. It was the purpose of the present study to examine the effects of Cyclosporin A on human gingival fibroblasts by means of biological and biochemical criteria. In this present study, we examined change of cell proliferation, cell activity, cell viability and cell cycle progression after application of Cyclosporin A. We also examined expression of cell cycle regulatory proteins by western blot analysis. Human gingival fibroblasts were cultured for 48 hours with application of Cyclosporin A at concentrations of 0.01, 0.1, 1, and 10 ng/ml. Cyclosporin A(1 ng/ml) significantly increased the cell activity of gingival fibroblast. Proliferation and viability of gingival fibroblasts were also increased in group treated with 1 ng/ml of Cyclosporin A compared to control group. In the cell cycle analysis, S phase was increased and G1 phase was decreased in the group treated with 1 ng/ml of Cyclosporin A. Cyclosporin A increased the expression of cdk4 and inhibited the expression of pRB and p21. These results suggest that 1 ng/ml of Cyclosporin A may increase the cell cycle progression of human gingival fibroblasts, and its mechanisms may increase the expression of cdk4 and decrease the expression of pRB and p21.

• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4571-4576
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• 2015

Background: To investigate the inhibitory effect and the underlying mechanism of triptolide on cultured human endometrial carcinoma HEC-1B cells and corresponding xenograft. Materials and Methods: For in vitro studies, the inhibition effect of proliferation on HEC-1B cell by triptolide was determined by MTT assay; cell cycle and apoptosis of the triptolide-treated and untreated cells were detected by flow cytometry. For in vivo studies, a xenograft tumor model of human endometrial carcinoma was established using HEC-1B cells, then the tumor-bearing mice were treated with high, medium, and low-dose ($8{\mu}g$, $4{\mu}g$ and $2{\mu}g/day$) triptolide or cisplatin at $40{\mu}g/day$ or normal saline as control. The mice were treated for 10-15 days, during which body weight of the mice and volume of the xenograft were weighted. Then expression of Bcl-2 and vascular endothelial growth factor (VEGF) was analyzed by SABC immunohistochemistry. Results: Cell growth was significantly inhibited by triptolide as observed by an inverted phase contrast microscope; the results of MTT assay indicated that triptolide inhibits HEC-1B cell proliferation in a dose and time-dependent manner; flow cytometry showed that low concentration (5 ng/ml) of triptolide induces cell cycle arrest of HEC-1B cells mainly at S phase, while higher concentration (40 or 80 ng/ml) induced cell cycle arrest of HEC-1B cells mainly at G2/M phase, and apoptosis of the cells was also induced. High-dose triptolide showed a similar tumor-inhibitory effect as cisplatin (-50%); high-dose triptolide significantly inhibited Bcl-2 and VEGF expression in the xenograft model compared to normal saline control (P<0.05). Conclusions: triptolide inhibits HEC-1B cell growth both in vitro and in mouse xenograft model. Cell cycle of the tumor cells was arrested at S and G2/M phase, and the mechanism may involve induction of tumor cell apoptosis and inhibition of tumor angiogenesis.