• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4357-4361
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• 2015

Thunbergia Laurifolia Linn. (TL) is one of the most familiar plants in Thai traditional medicine that is used to treat various conditions, including cancer. However, the antitumor activity of TL or its constituents has never been reported at the molecular level to support the folklore claim. The present study was designed to investigate the antitumor effect of an aqueous extract of TL in human breast cancer cells and the possible mechanism(s) of action. An aqueous crude extract was prepared from dried leaves of TL. Folin-Ciocalteu colorimetric assays were used to determine the total phenolic content. Antiproliferative and cell cycle effects were evaluated in human breast adenocarcinoma MCF-7 cells by MTT reduction assay, cell growth inhibition, clonogenic cell survival, and flow cytometric analysis. Free radical generation by the extracts was detected using electron paramagnetic resonance spectroscopy. The exposure of human breast adenocarcinoma MCF-7 cells to a TL aqueous extract resulted in decreases in cell growth, clonogenic cell survival, and cell viability in a concentration-dependent manner with an $IC_{50}$ value of $843{\mu}g/ml$. Treatments with extract for 24h at $250{\mu}g/ml$ or higher induced cell cycle arrest as indicated by a significant increase of cell population in the G1 phase and a significant decrease in the S phase of the cell cycle. The capability of the aqueous extract to generate radical intermediates was observed at both high pH and near-neutral pH conditions. The findings suggest the antitumor bioactivities of TL against selected breast cancer cells may be due to induction of a G1 cell cycle arrest. Cytotoxicity and cell cycle perturbation that are associated with a high concentration of the extract could be in part explained by the total phenolic contents in the extract and the capacity to generate radical intermediates to modulate cellular proliferative signals.

• 토지주택연구
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• 제3권3호
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• pp.271-278
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• 2012

전 지구적인 기후변화와 지구 온난화에 따라 서구 선진 국가들을 중심으로 저탄소 녹색성장(green growth)이 이슈로 등장하고 있고 이 전략은 미래의 성장동력으로까지 발전되고 있다. 저탄소 사회를 달성하기 위하여 세계 각국은 교토의정서를 체결하고 온실가스배출량을 2008년부터 2012년까지 1990년도 수준의 5.2%까지 줄이도록 선언하였다. 한편 급속한 도시개발과 불투수면적의 증가는 도시의 물순환의 변화를 초래한다. 본 연구에서는 녹색도시 개념을 검토하고 기존의 연구를 바탕으로 도시 및 단지수준에 적합한 물순환 계획요소를 검토하였다. 추가적으로 본 연구에서는 SWMM5-LID 수문모형을 이용하여 시범유역에 물순환 효과를 분석하였다. 물순환 분석은 개발전, 개발후, 녹색도시계획요소적용후(LID시설 적용후)에 대한 시범유역의 도시유출연속모의를 통하여 수행되었다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제6권12호
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• pp.543-548
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• 2017

최근에는 의료기기의 구성 요소 중 소프트웨어의 기능과 역할이 커지고, 의료기기 소프트웨어의 작동이 사용자의 생명과 안전에 직결되는 특성으로 인해 의료기기 소프트웨어의 안전성 보장에 대한 중요함은 더욱 강조되고 있다. 이를 위해 의료기기의 안전성을 효과적으로 보장할 수 있는 활동과 각각의 요구사항들을 제시하고 있는 여러 표준이 제정되었다. 표준들이 의료기기 소프트웨어의 안전성을 보장하기 위해 제시하는 활동으로는 크게 의료기기 소프트웨어의 개발생명주기와 위험관리 프로세스로 나뉜다. 이 두 활동은 개발 과정 중 동시에 진행되어야 하지만, 의료기기 소프트웨어 개발생명주기의 각 단계에서 수행되어야하는 위험관리 요구사항들은 분류되어있지 않다는 한계점이 있다. 이로 인해 개발자들은 의료기기 개발 중에 직접 표준들의 연관성을 분석하여 위험관리 활동을 수행해야한다. 따라서 본 논문에서는 의료기기 소프트웨어 개발생명주기와 위험관리 프로세스의 연관성을 분석하고, 위험관리 요구사항 항목들을 추출한다. 그리고 분석한 연관성을 토대로 추출된 위험관리 요구사항 항목을 개발생명주기에 대응시킴으로서, 의료기기 소프트웨어의 개발 중 효과적이고 체계적인 위험관리를 가능하게 한다.

• Molecules and Cells
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• 제37권2호
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• pp.126-132
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• 2014

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-metaphase I (Pro-MI), and localized to spindle poles at metaphase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibition. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at centromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromosome misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein ${\gamma}$-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.

• 전기화학회지
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• 제18권3호
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• pp.102-106
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• 2015

The performance of Li-B alloy as anode for molten salt electrolysis was firstly investigated. The crystalline phase of the prepared Li-B alloy was identified as $Li_7B_6$. The potential profile of Li-B alloy anode was monitored during the electrodeposition of $Nd^{3+}$ onto an LCC (liquid cadmium cathode) in molten LiCl-KCl salt at $500^{\circ}C$. The potential of Li-B alloy was increased from -2.0 V to -1.4 V vs. Ag/AgCl by increasing the applied current from 10 to $50mA{\cdot}cm^{-2}$. It was found that not only the anodic dissolution of Li to $Li^+$ but also the dissolution of the atomic lithium ($Li^0$) into the LiCl-KCl eutectic salt was observed, following the concomitant reduction of $Nd^{3+}$ by the $Li^0$ in Li-B alloy. It was expected that the direct reduction could be restrained by maintaining the anode potential higher that the deposition potential of neodymium.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1158-1162
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• 2006

The glyoxylate cycle can conserve carbons and adequately supply tricarboxylic acid (TCA) cycle intermediates for biosynthesis when microorganisms grow on $C_{2}$ carbon sources. It has been reported that isocitrate lyase (ICL1), a key enzyme of the glyoxylate cycle, is highly induced when Magnaporthe grisea, the causal agent of rice blast, infects its host. Therefore, the glyoxylate cycle is considered as a new target for antifungal agents. A 1.6-kb DNA fragment encoding the ICL1 from M. grisea KJ201 was amplified by PCR, cloned into a vector providing His-tag at the N-terminus, expressed in Escherichia coli, and purified using Ni-NTA affinity chromatography. The molecular mass of the purified ICL1 was approximately 60 kDa, as determined by SDS-PAGE. The ICL1 inhibitory effects of TCA cycle intermediates and their analogs were investigated. Among them, 3-nitropropionate was found to be the strongest inhibitor with an $IC_{50}$ value of $11.0{\mu}g/ml$. 3-Nitropropionate inhibited the appressorium development in M. grisea at the ${\mu}M$ level, whereas conidia germination remained unaffected. This compound also inhibited the mycelial growth of the fungus on minimal medium containing acetate as a $C_{2}$ carbon source. These results suggest that ICL1 plays a crucial role in appressorium formation of M. grisea and is a new target for the control of phytopathogenic fungal infection.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권5_6호
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• pp.503-514
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• 2003

폭포수 모형을 기반으로 하는 구조적 개발 방법론에서는 요구 분석 단계에서 요구 사항들이 일단 명세화되고 나면, 이들은 단지 후속의 개발 단계를 위한 중간 산출물로만 사용되고 더 이상 요구 사항 자체를 관리 대상으로 취급하지 않기 때문에 설계 단계 이후에 발생하는 요구 사항의 변경을 관리할 수 있는 절차가 미흡하다. 그러나 현실적으로는 정보 기술의 발전, 시장 환경이나 적용 환경의 변화 등으로 인하여 개발 기간 중 요구 사항은 끊임없이 변화하게 된다. 따라서 이러한 요구 사항의 지속적인 변경을 지원하기 위해서는 전체 개발 생명 주기에 걸쳐 요구 사항을 관리하고 특히 설계 단계 이후의 요구 사항 변경을 지원할 수 있는 요구 사항 변경 관리 프로세스가 필요하다. 이 논문에서는 하향식(top-down)의 구조적 개발 방법론에 적용할 수 있는 요구 사항 변경 관리 프로세스 모델을 제안하여 설계 단계 이후에 발생하는 요구 사항의 변경을 체계적으로 관리하고 요구 사항 자체를 모든 개발 생명 주기에서 활용하기 위한 방안을 제시한다. 제안 프로세스는 마르미 방법론의 개발 프로세스와 산출물 측면의 적용 검토를 통하여 개발 방법론의 요구 사항 변경 및 관리에 대한 개선 효과를 평가한다.

• 소성∙가공
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• 제23권2호
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• pp.110-115
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• 2014

Low cycle fatigue characteristics are very important in the development of automobile suspension parts. Fatigue properties using the strain life approach are usually obtained from low cycle fatigue tests. However, low cycle fatigue testing requires a lot of time and cost. In the current study, an attempt to estimate low cycle fatigue properties of high strength steel sheet from tensile test and tensile simulations is performed. In addition, low cycle fatigue testing was conducted to compare the fatigue properties obtained from tensile testing and simulations. In conclusion, the results effectively predict the low cycle fatigue properties. However, some deviations still exist.

• BMB Reports
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• 제36권1호
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• pp.60-65
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• 2003

Cancer is frequently considered to be a disease of the cell cycle. As such, it is not surprising that the deregulation of the cell cycle is one of the most frequent alterations during tumor development. Cell cycle progression is a highly-ordered and tightly-regulated process that involves multiple checkpoints that assess extracellular growth signals, cell size, and DNA integrity. Cyclin-dependent kinases (CDKs) and their cyclin partners are positive regulators of accelerators that induce cell cycle progression; whereas, cyclin-dependent kinase inhibitors (CKIs) that act as brakes to stop cell cycle progression in response to regulatory signals are important negative regulators. Cancer originates from the abnormal expression of activation of positive regulators and functional suppression of negative regulators. Therefore, understanding the molecular mechanisms of the deregulation of cell cycle progression in cancer can provide important insights into how normal cells become tumorigenic, as well as how cancer treatment strategies can be designed.

• 한국기계가공학회지
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• 제8권2호
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• pp.18-24
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• 2009

The most dominate aspect in machine works using CNC devices in industrial production processes is the precision of the product and the Cycle Time. To this day, many studies on the external factors of the technology to reduce the Cycle Time have advanced amid to the advancements in cam soft development for manual programs and the numerous studies on high speed and precision machining. This study experimented various functions of the sequence pattern flow and arranged system development technologies of past few years to develop and applicate various usage of adjustment factors within the CNC, so it would be more understandable to the user and would enable them to make high speed and precision products more faster develop and. In order to reduce the Cycle Time, the mechanism of machine tools has to be analysed and applied, in addition to program reduction and improvement of the manufacture process.