• 대기
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• 제29권5호
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• pp.671-687
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• 2019

This study evaluates the long-term seasonal predictability of summer (June, July and August) heatwaves over South Korea using 30-year (1989~2018) Hindcast data of the Pusan National University Coupled General Circulation Model (PNU CGCM)-Weather Research and Forecasting (WRF) chain. Heatwave indices such as Number of Heatwave days (HWD), Heatwave Intensity (HWI) and Heatwave Warning (HWW) are used to explore the long-term seasonal predictability of heatwaves. The prediction skills for HWD, HWI, and HWW are evaluated in terms of the Temporal Correlation Coefficient (TCC), Root Mean Square Error (RMSE) and Skill Scores such as Heidke Skill Score (HSS) and Hit Rate (HR). The spatial distributions of daily maximum temperature simulated by WRF are similar overall to those simulated by NCEP-R2 and PNU CGCM. The WRF tends to underestimate the daily maximum temperature than observation because the lateral boundary condition of WRF is PNU CGCM. According to TCC, RMSE and Skill Score, the predictability of daily maximum temperature is higher in the predictions that start from the February and April initial condition. However, the PNU CGCM-WRF chain tends to overestimate HWD, HWI and HWW compared to observations. The TCCs for heatwave indices range from 0.02 to 0.31. The RMSE, HR and HSS values are in the range of 7.73 to 8.73, 0.01 to 0.09 and 0.34 to 0.39, respectively. In general, the prediction skill of the PNU CGCM-WRF chain for heatwave indices is highest in the predictions that start from the February and April initial condition and is lower in the predictions that start from January and March. According to TCC, RMSE and Skill Score, the predictability is more influenced by lead time than by the effects of topography and/or terrain feature because both HSS and HR varies in different leads over the whole region of South Korea.

• Journal of Nutrition and Health
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• 제52권2호
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• pp.157-167
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• 2019

본 연구에서는 ice plant의 ethanol 추출물과 분획물의 항산화 및 대장암세포 성장억제 활성을 in vitro 수준에서 평가하는 것을 목적으로 하였다. Ethanol 추출물의 총 폴리페놀 함량 (3.7 mg GAE/g), 총 카로티노이드 함량 ($13.2{\mu}g/g$), DPPH 라디칼 소거활성 (21.0%), 철 환원력 (21.0%)보다 butanol 분획물의 총 폴리페놀 함량 (5.4 mg GAE/g), 총 카로티노이드 함량 ($86.6{\mu}g/g$), DPPH 라디칼 소거활성 (34.9%), 철 환원력 (80.8%)이 더 높았다. 또한 HCT116 대장암세포에서 세포 내 활성산소종 수준을 감소시키거나 세포 성장을 억제하는데 있어서 ethanol 추출물보다 butanol 분획물의 활성이 더 컸다. 대장암세포의 성장을 억제하는데 있어서 butanol 분획물이 ethanol 추출물보다 더 효과적이었던 것은 butanol 분획물의 apoptosis 유도활성이 ethanol 추출물의 활성보다 더 컸고 butanol 분획물만이 G2/M기억류활성을 나타냈기 때문인 것으로 생각된다. 앞으로 이와 같은 결과를 초래하는 주요 활성성분을 분리 동정하고 ice plant의 항산화 활성 및 대장암세포 성장억제 효과가 in vivo 수준에서 재현되는지 검증하며 이와 관련된 세부기전을 탐색하는 심도 있는 연구가 필요할 것으로 생각된다.

• 대한수학회논문집
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• 제32권2호
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• pp.375-387
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• 2017

In this paper, we prove some coincidence point theorems involving ${\varphi}-contraction$ in ordered partial metric spaces. We also extend newly introduced notion of g-comparability of a pair of maps for linear contraction in ordered metric spaces to non-linear contraction in ordered partial metric spaces. Thus, our results extend, modify and generalize some recent well known coincidence point theorems of ordered metric spaces.

• 한국임상수의학회지
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• 제19권2호
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• pp.268-271
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• 2002

Transitional cell carcinoma(TCC) was identified by cytological and ultrasonographic findings in an 11-year-old, intact female Yorkshire terrier with intermittent hematuria for three years. In color-doppler ultrasound images there was marked irregular wall thickness of the bladder surface and well-defined hyperechoic focal lesions within the mass. Active vascular response was observed in the surroundings of hyperechoic lesions.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2006년도 춘계학술발표대회 및 제10회 신소재 심포지엄 논문개요집
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• pp.29.2-29.2
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• 2006

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.261-264
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• 2001

점안약에 광범위하게 사용되는 보존제(preservatives)의 세포독성 및 항균활성 및 항진균 활성을 검정하였다. 세포독성은 L929 세포를 사용하였으며, 항균항진균 활성검정에 사용된 균주는 Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923 등 2가지이고, 진균은 Trichoderma reesei A TCC6967을 사용하였다. 사용된 시약은 합성보존제인 benzalkoniumchloride(BAK)와 천연보존제인 키토산이며 키토산의 분자량은 60,000, 탈아세틸화도는 95%, 점도는 2cps였다. L929 세포에 대해 24hr, 48hr, 72hr에 대해 각각 농도에 따른 세포독성검정 결과 세포의 30% 이상 성장저해를 일으키는 농도는 BAK의 경우 0.001%였고, 키토산의 경우는 0.6%였으며 이 결과는 시간에 따라 유의성 있는 변화가 없었다. 각 각의 균에 대한 BAK 의 항균항진균 활성을 나타내는 최소저해농도는 P.aeruginosa에는 0.1%였고, S. aureus에는 0.001 %였으며 T reesel'에는 0.1%였다. 키토산은 P. aeruginosa의 경우 2%, S. aureus가 1%에서 2일간 정균작용을 나타내었다. 진균에 대해서는 농도 의존적으로 생육을 촉진시켰다. 천연보존제는 합성보존제에 비해 독성을 일으키지 않으며 약리작용이 있는 반면에 항균성이 떨어지므로 이에 대한 연구가 더 필요하다.

• 한국세라믹학회지
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• 제48권4호
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• pp.323-327
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• 2011

The effects of $Dy_2O_3$ and $Er_2O_3$ co-doping on electrical properties and temperature stability of barium titanate ($BaTiO_3$) ceramics were investigated in terms of microstructure and structural analysis. The dielectric constant and the insulation resistance (IR) of 0.7 mol% $Dy_2O_3$ and 0.3 mol% $Er_2O_3$ co-doped dielectrics had about 60% and 20% higher than the values of undoped one, respectively, and the temperature coefficient of capacitance (TCC) met the X7R specification. The addition of $Dy_2O_3$ contributed to electrical properties caused by increase of tetragonality; however, preferential diffusion of $Dy^{3+}$ ions toward A site in $BaTiO_3$ grain exhibited an adverse effect on temperature stability by grain growth. On the other hand, The $Er_2O_3$ addition in $BaTiO_3$ could affect the TCC behavior and the IR with suppression of grain growth caused by reinforcement of grain boundary and electrical compensation. Therefore, the enhanced electrical properties and temperature stability through the co-doping could be deduced from the increase of tetragonality and the suppression of grain growth.

• 한국전기전자재료학회논문지
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• 제21권7호
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• pp.645-651
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• 2008

To reduce noise in high frequency and distortion of signal, the composition of $(Ca_{0.7}Sr_{0.3})(Zr_{0.97}Ti_{0.03})O_3$ and $(Ba_{0.2}Ca_{0.4}Sr_{0.4})TiO_3$ was developed. The composition was not solid solution, but mixtures of various phases composed of Ca, Sr, Zr, Ti and Ba oxides. The dielectric constant increased, the quality factor and the insulation resistance decreased with $(Ba_{0.2}Ca_{0.4}Sr_{0.4})TiO_3$ content. The composition of $0.4(Ba_{0.2}Ca_{0.4}Sr_{0.4})TiO_3$ satisfied the electric characteristics and the temperature coefficient of dielectric constant (TCC). In addition, the glass frit and $MnO_2$ also affected the electric characteristics. From the result of the best fit simulation, $MnO_2$ 0.3 mol%, the glass frit 0.6 wt% showed the insulation resistance $906{\Omega}{\cdot}F$, the quality factor 821, and the dielectric constant 92. With the selected composition, MLCC capacitors sized $4.5{\times}3.2{\times}2.5mm$ were manufactured with 105 layered of the dielectric thickness $16{\mu}m$ using Ni inner electrode, They represented the capacitance $98{\sim}102$ nF, the quality factor 1,200 and the insulation resistance $1,500{\Omega}{\cdot}F$. Also, they had high break-down voltage with $107{\sim}115V/{\mu}m$, and satisfied the SL TCC characteristics.

• 한국동물위생학회지
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• 제40권1호
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• pp.47-52
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• 2017

The main goal of this survey was to assess the current sanitation status and safety standards of meat processed products purchased at instant meat sales and processing operators. Analyses were carried out from April to September in 2016 in Gwangju area, Republic of Korea. A total number of 150 samples including seasoned meats, ground meat products, meat extract products, heated seasoned meats, sausages and hams from 35 butcher shops was collected. The number of inappropriate cases was revealed eleven cases (7.3%) in total viable count of bacteria (TVC), total coliform counts (TCC) and Listeria monocytogenes. The reported data indicate that more systemic and technical guidance is needed to monitor instant meat sales and processing operators in order to guarantee safety of meat processed products.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1207-1213
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• 2016

Heat stress negatively affects milk quality altering its nutritive value and cheese making properties. This study aimed at assessing the impact of seasonal microclimatic conditions on milk quality of Friesian cows. The study was carried out in a dairy farm from June 2013 to May 2014 at Beni-Suef province, Egypt. Inside the barn daily ambient temperature and relative humidity were recorded and used to calculate the daily maximum temperature-humidity index (mxTHI), which was used as indicator of the degree of heat stress. The study was carried out in three periods according to the temperature-humidity index (THI) recorded: from June 2013 to September 2013 (mxTHI>78), from October 2013 to November 2013 (mxTHI 72-78) and from December 2013 to April 2014 (mxTHI<72). Eighty Friesian lactating dairy cows were monitored in each period. The three groups of cows were balanced for days in milk and parity. Milk quality data referred to somatic cell count, total coliform count (TCC), faecal coliform count (FCC), Escherichia coli count, percentage of E. coli, and Staphylococcus aureus, percentage of fat, protein, lactose, total solid and solid non-fat. Increasing THI was associated with a significant decrease in all milk main components. An increase of TCC, FCC, and E. coli count from mxTHI<72 to mxTHI>78 was observed. In addition, the isolation rate of both S. aureus and E. coli increased when the mxTHI increased. The results of this study show the seriousness of the negative effects of hot conditions on milk composition and mammary gland pathogens. These facts warrant the importance of adopting mitigation strategies to alleviate negative consequences of heat stress in dairy cows and for limiting related economic losses.