• E2M - 전기 전자와 첨단 소재
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• 제9권6호
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• pp.578-583
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• 1996

The magnetic properties have been investigated for the system of $Y_{1-x}$Yb$_{x}$Ba$_{2}$Cu$_{3}$F$_{y}$O$_{y}$ with x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5. In the magnetic hysteresis measurements, the values of the magnetic critical current densities are in the range of 10$^{4}$-10$^{5}$ A/cm$^{2}$ at the maximum external field 1.4 T. The upper critical field is over 100 T. The critical current density is estimated by the magnetization width .DELTA.M through the Bean critical state model. As the field strength is increased, the .DELTA.M diminishes slowly. The .DELTA.M for the fluorinated sample also decreases slowly with increasing field. It is considered that the large J, value results from this type is due to enhanced pinning center in grain boundary.y.ary.y.

• 한국초전도ㆍ저온공학회논문지
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• 제11권2호
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• pp.1-6
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• 2009

We report a successful fabrication of $high-J_c\;NdBa_2Cu_3O_{7-{\delta}}$ (NdBCO) films on $SrTiO_3$(STO) (100) substrates by pulsed laser deposition (PLD) in a relatively wide processing window. Under various oxygen pressures controlled by either 1%$O_2$/Ar mixture gas or pure $O_2$ gas, strongly c-axis oriented NdBCO films were grown at the substrate temperature $(T_s)\;of\;800^{\circ}C$ in 800 mTorr with 1%$O_2$/Ar gas and also in 400 and 800 mTorr with pure $O_2$ gas. These samples exhibited $T_c$ values over 90K and $J_c$ values of $2.8-3.5MA/cm^2$ at 77K in self-field (77K, sf). On the other hand, $J_c$ values over $1A/cm^2$ were obtained at the temperature regions of $700-830^{\circ}C$ in 800 mTorr with 1%$O_2$/Ar gas at those of $750-830^{\circ}C$ in 800 mTorr with pure $O_2$ gas. Unlike previous reports, resent results support that the PLD processing window for high-Jc NdBCO films is not narrow.

• Asian-Australasian Journal of Animal Sciences
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• 제32권5호
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• pp.629-636
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• 2019

Objective: The study was designed to determine the cytotoxic effect of gallic acid (GA), obtained by the hydrolysis of tannins, on mice TM4 Sertoli cells apoptosis. Methods: In the present study, non-tumorigenic mice TM4 Sertoli cells were treated with different concentrations of GA for 24 h. After treatment, cell viability was evaluated using WST-1, mitochondrial dysfunction, cells apoptosis and necrosis was detected using JC-1, Hoechst 33342 and propidium iodide staining. The expression levels of Cyclin B1, proliferating cell nuclear antigen (PCNA), Bcl-2-associated X protein (BAX), and Caspase-3 were also detected by quantitative real-time polymerase chain reaction and Western-blotting. Results: The results showed that 20 to $400{\mu}M$ GA inhibited viability of TM4 Sertoli cells in a dose-dependent manner. Treatment with $400{\mu}M$ GA significantly inhibited PCNA and Cyclin B1 expression, however up-regulated BAX and Caspase-3 expression, caused mitochondrial membrane depolarization, activated Caspase-3, and induced DNA damage, thus, markedly increased the numbers of dead cells. Conclusion: Our findings showed that GA could disrupt mitochondrial function and caused TM4 cells to undergo apoptosis and necrosis.

• 한국의류학회지
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• 제42권1호
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• pp.172-182
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• 2018

The purpose of the present study was to quantify the thermal insulation of garments by item and examine factors influencing clothing insulation. A total of 769 garments in clo unit were collected and classified into 12 categories: blouses/shirts (95 items, BS), T-shirts/sweaters (62 items, TS), vest (23 items, VT), cardigans (23 items, CD), jackets/coats (75 items, JC), sport outerwear (including padding jackets)(48 items, SO), trousers (23 items, TR), skirts (56 items, SK), dresses (28 items, DS), underwear (150 items, UW), sleepwear (50 items, SW), and personal protective clothing (59 items, PPC). The results showed that clothing insulation was $0.21{\pm}0.01clo$ for the BS, $0.22{\pm}0.01clo$ for TS, $0.12{\pm}0.00clo$ for VT, $0.23{\pm}0.02clo$ for CD, $0.40{\pm}0.02clo$ for JC, $0.49{\pm}0.03clo$ for SO, $0.21{\pm}0.01clo$ for TR, $0.18{\pm}0.01clo$ for SK, $0.34{\pm}0.03clo$ for DS, $0.09{\pm}0.01clo$ for UW, $0.42{\pm}0.03clo$ for SW, and $0.56{\pm}0.03clo$ for PPC (p<.001). The most influential factors among the seven factors for thermal insulation of garments were clothing weight and covering area; however, the explanatory powers of two factors differed according to clothing categories. The covering area had more significant impact on clothing insulation in cardigans, jackets/coats, trousers, and dresses than clothing weight. Covering areas and clothing weight were the most influential factors in the following categories: blouses/shirt, T-shirts/sweaters, skirts, sleepwear and personal protective clothing. The garment weight was the most important factor for thermal insulation for the sport outerwear.

• 생명과학회지
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• 제18권12호
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• pp.1631-1636
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• 2008

대황(Rhei Rhizoma; RR, 대황(大黃))은 Rheum officinale Baill.와 Rheum palmatum L. (Polygonaceae)의 땅속부분 (rhizome 및 root)으로 남아시아의 민속의학에서 간 및 신장의 손상을 치료하는데 널리 이용되고 있다. 본 연구에서는 배양한 흰쥐 해마신경세포의 저산소증모델을 이용하여 대황의 물추출물이 신경세포사를 억제하는 효능에 대하여 조사하였다. 배양 10일(DIV10)에 RR을 배양액에 첨가하고 DIV13일에 생존율을 조사한 결과 10 ${\mu}g$/ml 농도까지는 세포독성이 없었으며, 정상산소 환경에서 2.5 ${\mu}g$/ml의 농도에서 세포생존율을 높이는 것으로 나타났다. 또한 배지에 대황을 첨가한 경우 DIV13일에 저산소증을 유도한 후 5일째에 세포생존율을 조사한 결과 대조군에 비하여 매우 유의하게 생존율을 증가시켰다. $H_2DCF$ 염색 결과 대황은 활성산소(ROS)의 생성을 유의하게 감소시킴과, JC-1 염색 결과 사립체 막전위의 소실을 유의하게 억제함을 알 수 있었다. 이러한 결과들은 대황 물추출물이 활성산소를 효과적으로 제거하고, 세포의 에너지 생성을 보전함으로서 세포사를 억제할 수 있음을 보여주며, 향후 뇌신경세포의 건강에 유용하게 이용될 수 있음을 시사한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.93-100
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• 2014

Background: Curcumin has has been reported to exert anti-inflammatory, anti-oxidation and anti-angiogenic activity in various types of cancer. It has also been shown to induce apoptosis in leukemia cells. We aimed to unravel the role of the redox pathway in Curcumin mediated apoptosis with a panel of human leukemic cells. Materials and Methods: In this study in vitro cytotoxicity of Curcumin was measured by MTT assay and apoptotic effects were assessed by annexin V/PI, DAPI staining, cell cycle analysis, measurement of caspase activity and PARP cleavage. Effects of Curcumin on intracellular redox balance were assessed using fluorescent probes like $H_2DCFDA$, JC1 and an ApoGSH Glutathione Detection Kit respectively. Results: Curcumin showed differential anti-proliferative and apoptotic effects on different human leukemic cell lines in contrast to minimal effects on normal cells. Curcumin induced apoptosis was associated with the generation of intracellular ROS, loss of mitochondrial membrane potential, intracellular GSH depletion, caspase activation. Conclusions: As Curcumin induces programmed cell death specifically in leukemic cells it holds a great promise as a future therapeutic agent in the treatment of leukemia.

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.21-25
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• 2002

The effect of Ca-doping on the superconducting properties of Nd-Ba-Cu-O bulk superconductors, fabricated by the oxygen-controlled melt growth process, has been systematically investigated. Various c-axis textured bulk samples were grown using precursors with the nominal compositions of $Nd_{1.8-x}Ca_{x]Ba_{2.4}Cu_{3.4}O_{y}$ (x= 0.00, 0.02, 0.05, 0.10, 0.15) in a reduced oxygen atmosphere of 1%O$_2$ in Ar. Magnetization measurements revealed that the critical temperatures(Tc) were almost linearly depressed from 95K to 86K with increasing the Ca dopant from x : 0.0 to 0.15, respectively, and thus critical current densities(Jc) at 77K and for H//c-axis of specimens were gradually degraded with increasing x. Compositional analyses revealed that although the amounts of the Ca dopant both in $NdBa_2Cu_2O_y(Nd123) and Nd_4Ba_2Cu_2O_{10}(Nd422)$,/TEX> were increased with increasing x, only less than half of the initial Ca compositions were detected in melt-grown Ca-doped Nd-Ba-Cu-O bulk crystals. The supression of Tc is attributed to an increased Nd substitution for the Ba site in the Nd123 superconducting matrix with increasing the amount of the Ca dopant.

• 대한한방내과학회지
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• 제29권4호
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• pp.835-845
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• 2008

Objectives : The purpose of this study was to investigate the effect of FS for the modulation of ROS and MMP in a hypoxic model of cultured rat cortical cells. Methods : For the effect of FS on the viability, FS was added to culture media (neurobasal supplemented with B27) and cell viability was measured by LDH assay. To investigate the effects of FS on ROS generation and MMP preservation, cells grown in FS-containing media were given a hypoxic shock(2% $O_2/5%$ $CO_2$, $37^{\circ}C$, 3 hrs) on DIV 10, stained with $H_2DCF-DA$(10 nM) and JC-1, respectively, and observed by fluorescent microscope. Results : 1. FS has a protective effect of cortical cells in both normoxia and hypoxia. 2. FS reduced the generation of ROS and this reduction was especially significant at 3 days after hypoxia. 3. FS was effective for the maintenance of MMP in hypoxia, and this efficacy was especially significant at 3 days after hypoxia. Conclusions : Taken together, these results indicate that FS attenuates ROS generation and MMP dissipation, which eventually protects from neuronal cell death in hypoxia.

• 시스템엔지니어링학술지
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• 제11권1호
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• pp.9-24
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• 2015

Construction industry faces a lot of inherent uncertainties and issues and the construction phase of nuclear power project is not free from this risk. This paper investigates promising methodologies to be used on nuclear power plant (NPP) construction schedule delay risk assessment by using entry level systems engineering approach. This study contains how the initial concept for the risk assessment methodology has been developed. In this point of view, this work structured on three main phases: needs analysis (NA), concept exploration (CE), and concept definition (CD) through systems engineering (SE) approach. Traditionally, the SE process is applied to technical development programs but this study opens up a new avenue that SE can also be successfully applied to the development and optimization of the risk assessment model. This study provides a rational and systematic process for developing and selecting the best risk assessment model. This paper selects analytic hierarchy process (AHP) method to assess NPP construction schedule delay risk for international project. As conclusion, the proposed concept and selected method can discriminate successfully and clearly among schedule delay risk assessment methods.

• 상하수도학회지
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• 제28권1호
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• pp.33-45
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• 2014

In this study, current sewer infiltration/Inflow(I/I) computation and application method was examined about improvement and adequacy relating to the main issues raised by the field for practitioners. The results of review about infiltration calculation method were considered to be in need of improvement at 'standards of minimum sewage calculation'. Furthermore, the results of review about I/I application method were considered to be in need of improvement at 'standards of seasonal infiltration application' and 'the relative decrease in the Annual evaluation standards'. In addition, annual I/I analysis at JC County for the four years(2009~2012) in respect of operation flow and rainfall data was conducted. The result of annual infiltration analysis, compared average daily sewage generated average infiltration rate was found in 21.95 %, infiltration by unit was found in $0.31m^3/day/cm/km$ and $0.12m^3/day/day$, respectively. The result of annual inflow analysis, average rainfall - Inflow equations was found $y=5.499{\times}$($R^2$ 0.793), and the average Inflow quantity by sewer extension was predicted to $0.66m^3/mm-km$.