• 대한전자공학회논문지SD
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• 제42권10호
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• pp.9-18
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• 2005

Si, GaAs, InP 및 $In_{0.53}Ga_{0.47}AS$ 계단형 $p^{+}n$ 접합에서의 항복전압을 위한 해석적 표현식을 유도하였다. 해석적 항복전압을 위해 각 물질에 대한 Marsland의 lucky drift 파라미터를 이용하여 유효이온화계수를 각각 추출하였고, 이의 이온화 적분을 통해 얻은 해석적 항복전압 결과는 $10^{14}cm\;^{-3}\~5\times10\;^{17}cm\;^{-3}$도핑 농도 범위에서 실험 결과와 $10\%$ 오차 범위 이내로 잘 일치하였다.

• 산업과 과학
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• 제1권2호
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• pp.17-23
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• 2022

본 연구는 농촌과 도시에 거주하는 노인 여성들의 체력과 낙상효능감에 대해 분석하여 지역에 따른 노인들의 건강요인들을 분석하기 위함이다. 본 연구 대상자는 주 2회 이상 지역 마을회관에서 건강체조와 치어리딩를 하는 농촌 및 도시에 거주하는 노인 여성 98명(REG; n=46, 77.53±6.37 yrs, 151.81±5.26 cm, 60.00±9.42 kg, UEG; n=53, 73.57±2.70 yrs, 154.07±3.52 cm, 57.37±2.06 kg)으로 진행되었다. 체력은 근지구력, 심폐지구력, 유연성을 측정하였으며, 낙상효능감은 Tinetti 등이 개발한 10개 항목의 Fall Efficacy Scale을 사용하였다. 도시 노인들이 유연성과 낙상효능감에서 유의한 차이가 나타났다(p<.01, p<.05). 근지구력과 심페지구력에서는 유의한 차이가 나타나지 않았다(p>.05). 추후 지역의 노인들의 건강요인의 불균형을 개선하기 위한 연구가 지속적으로 이루어져야 할 것이다.

• Molecules and Cells
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• 제38권6호
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• pp.518-527
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• 2015

Controlled release of medications remains the most convenient way to deliver drugs. In this study, we precipitated gold nanoparticles with quercetin. We loaded gold-quercetin into poly(DL-lactide-co-glycolide) nanoparticles (NQ) and tested the biological activity of NQ on HepG2 hepatocarcinoma cells to acquire the sustained release property. We determined by circular dichroism spectroscopy that NQ effectively caused conformational changes in DNA and modulated different proteins related to epigenetic modifications and c ell cycle control. The mitochondrial membrane potential (MMP), reactive oxygen species (ROS), cell cycle, apoptosis, DNA damage, and caspase 3 activity were analyzed by flow cytometry, and the expression profiles of different anti- and pro-apoptotic as well as epigenetic signals were studied by immunoblotting. A cytotoxicity assay indicated that NQ preferentially killed cancer cells, compared to normal cells. NQ interacted with HepG2 cell DNA and reduced histone deacetylases to control cell proliferation and arrest the cell cycle at the sub-G stage. Activities of cell cycle-related proteins, such as $p21^{WAF}$, cdk1, and pAkt, were modulated. NQ induced apoptosis in HepG2 cells by activating p53-ROS crosstalk and induces epigenetic modifications leading to inhibited proliferation and cell cycle arrest.

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.177-182
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• 2012

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the first time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet significantly decreased the viability of A549 cells at $5-15{\mu}M$. Tetrazolium violet -induced apoptosis in A549 cells was confirmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These findings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.

• Journal of Korean Neurosurgical Society
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• 제58권4호
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• pp.341-345
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• 2015

Objective : To measure the orientation of the facet joints of cervical spine (C-spine) segments in the sagittal plane, known as the pedicle-facet (P-F) angle, and to use these measurements to evaluate the relationship between the P-F angle and the amount of vertebral anterolisthesis in patients with degenerative cervical spondylolisthesis (DCS). Methods : A retrospective case-control study was performed including 30 age- and sex-matched patients with DCS and 30 control participants. Anterior-posterior and lateral view radiographs of the C-spine were obtained in a standing position. The P-F angle at all cervical levels and the amount of anterolisthesis at C4-5 were measured from lateral view plain radiographs. Results : The P-F angles at C4-5 were $141.14{\pm}7.14^{\circ}$ for the DCS group and $130.53{\pm}13.50^{\circ}$ (p=0.012) for the control group, and at C5-6 were $137.46{\pm}8.53^{\circ}$ for the DCS group and $128.53{\pm}16.01^{\circ}$ for the control group (p=0.001). The mean P-F angle at C4-5 did not correlate with the amount of anterolisthesis (p=0.483). The amount of anterior slippage did correlate with age (p<0.001). Conclusion : The P-F angle was intrinsically higher at C4-5, compared to C5-6, in both the DCS and control groups, which might explain the increased likelihood for anterolisthesis of C4. Higher P-F angles in the DCS group may be a predisposing factor to slippage. The P-F angle may interact with age to increase incidence of anterolisthesis with increasing age.

• Journal of Korean Neurosurgical Society
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• 제49권1호
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• pp.13-19
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• 2011

Objective: The purpose of this study is to investigate the combined effects of ginkgo biloba extract, ginkgolide A and B and aspirin on SK-N-MC, human neuroblastoma cell viability and mRNA expression of growth associated protein43 (GAP43), Microtubule-associated protein 2 (MAP2), B-cell lymphoma2 (Bcl2) and protein53 (p53) gene in hypoxia and reperfusion condition. Methods: SK-N-MC cells were cultured with Dulbecco's Modified Eagle's Medium (DMEM) media in $37^{\circ}C$, 5% $CO_2$ incubator. The cells were cultured for 8 hours in non-glucose media and hypoxic condition and for 12 hours in normal media and $O_2$ concentration. Cell survival rate was measured with Cell Counting Kit-8 (CCK-8) reagent assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to estimate mRNA levels of GAP43, MAP2, Bcl2, and p53 genes. Results: The ginkgolide A and B increased viable cell number decreased in hypoxic and reperfused condition. The co-treatment of ginkgolide B with aspirin also increased the number of viable cells, however, there was no additive effect. Although there was no increase of mRNA expression of GAP43, MAP2, and Bcl2 in SK-N-MC cells with individual treatment of ginkgolide A, B or aspirin in hypoxic and reperfused condition, the co-treatment of ginkgolide A or B with aspirin significantly increased GAP43 and Bcl2 mRNA levels. In MAP2, only the co-treatment of ginkgolide A and aspirin showed increasing effect. The mRNA expression of p53 had no change in all treating conditions. Conclusion: This study suggests that the combined treatments of Ginkgo biloba extracts and aspirin increase the regeneration of neuroblastoma cells injured by hypoxia and reperfusion.

• 한국균학회지
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• 제28권1호
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• pp.55-59
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• 2000

까치버섯(Polyozellus multiplex) 메탄올 추출물과 물 추출물은 산화 유발물질인 $H_2O_2$에 대하여 메탄올 추출물과 물 추출물에서 각각 53.5%, 29.4%의 생존율을 보여 까치버섯 추출물의 항산화 효과를 확인하였다. 까치버섯 메탄올 추출물과 물 추출물을 이용하여 동물에 강력한 발암물질인 MHNG를 투여한 후 항산화 효소계를 측정한 결과, 물 추출물은 항산화효소인 glutathione S-transferase(GST)와 superoxide dismutase(SOD) 활성과 조직내의 해독물질인 glutathione(GSH)의 함량을 높여 주었다. 또한 0.5%의 까치버섯 물 추출물은 암억제 유전자인 p53회 발현을 매우 증가시켰다. 이상의 결과로 까치버섯(Polyozellus multiplex)은 항산화 능이 있으며 특히, 물 추출물은 체내의 항산화 효소를 활성화시키고 항산화 물질의 함량을 높여주었고 암 억제유전자인 p53의 발현을 증가시켜 항암효과가 있음을 보여주었다.

• 콘크리트학회지
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• 제10권3호
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• pp.53-61
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• 1998

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 춘계학술발표대회 요약집
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• pp.53.1-53.1
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• 2003

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1769-1772
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• 2016

Background: Urothelial papilloma and non-invasive papillary carcinoma are common neoplasms of the urinary bladder. Distinguishing papillomas and papillary carcinomas, especially the low grade type, is often debatable on the basis of histological features alone. Materials and Methods: We investigated immunohistochemical expression of cytokeratin 20 (CK20), p53, and Ki-67 in a group of 20 urothelial papilloma cases and 30 noninvasive papillary neoplasms of low malignant potential (PNLMP) of the urinary bladder. Whole tissue sections were examined. Results: Among the 30 carcinoma cases, 12 (40%) showed strong reactivity for the whole panel, 16 (53%) reacted positively for two markers, and 2 (7%) reacted just to one of them. Ki-67 was considered positive in 27 cases (90%) and p53 in 24 (80%), CK20 showed positive reactivity in 21 cases (70%). Only small percentages of papillomas were positive, and then only weakly. Conclusions: We concluded that the intense positivity of suspicious cells for at least one of these markers would confirm the presence of malignant changes and favours the diagnosis of carcinoma.