• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.369-376
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• 2008

In the present study, we investigated the radioprotective effect of cyclo(L-phenylalanyl-L-prolyl) on irradiated rat lungs to determine its potential as a radioprotective agent. We found that early lung damage induced by irradiation was reduced by treatment with 40mg/kg of cyclo(L-phenylalanyl-L-prolyl) in the latent and early pneumonitis phases. Expression of $TNF-{\alpha}\;and\;TGF-{\beta}1$ at 2 and TGF-${\beta}1$ at 8 weeks post-irradiation was decreased in animals that received both radiation and cyclo(L-phenylalanyl-L-prolyl) compared with animals that received radiation alone. Evidence indicated that the proinflammatory cytokine TNF-${\alpha}$ and the fibrogenic cytokine TGF-${\beta}1$ likely play a role in the radioprotective effect of cyclo(L-phenylalanyl-L-prolyl). However, besides TNF-${\alpha}$ and TGF-${\beta}1$ expressions, the precise mechanism by which cyclo(L-phenylalanyl-L-prolyl) ameliorates the induced radiation damage is not clear.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제10권3호
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• pp.230-241
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• 2010

In the present paper we introduce and study fundamental concepts in the framework of L-fuzzifying topology(so called(2,L)-fuzzy topology)as L-concepts where L is a complete residuated lattice. The concepts of (2,L)-derived, (2,L)-closure, (2,L)-interior, (2,L)-exterior and (2,L)-boundary operators are studied and some results on above concepts are obtained. Also, the concepts of an L-convergence of nets and an L-convergence of filters are introduced and some important results are obtained. Furthermore, we introduce and study bases and subbases in (2,L)-topology. As applications of our work the corresponding results(see[10-11]) are generalized and new consequences are obtained.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.300-303
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• 2005

대전지역 화강암지대에 존재하는 75개 지하수를 5개 지역구에서 채취하였으며, 상ㅁ하반기 동안 2차례 시료를 채취하여 건기와 우기후의 라돈 및 우라늄 농도를 분석하였다. 5개 지역에 대한 라돈과 우라늄의 평균 농도는 유성구에서 270.9 Bq/L, $43.8{\mu}g/L$ 였으며, 동구의 경우 41.3 Bq/L, $4.9{\mu}g/L$, 대덕구는 131.8 Bq/L, $54.3{\mu}g/L$, 중구의 경우 44.0 Bq/L, $8.1{\mu}g/L$ 그리고 서구는 112.9 Bq/L, $0.4{\mu}g/L$ 이었다. 라돈과 우라늄의 함량은 건기가 우기후에 비해 대체로 높게 나타났으며 건기시의 평균값은 라돈은 $253{\pm}14\;Bq/L$ 우라늄은 $63{\mu}g/L$ 이었으며, 우기시는 $195{\pm}11\;Bq/L,\;45.4{\mu}g/L$ 이었다.

• 영어어문교육
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• 제18권1호
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• pp.115-132
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• 2012

In order to confirm ecological validity of D$\ddot{o}$rnyei's second language motivational self, the present study investigated 495 South Korean secondary school students' L2 learning motivation and motivated behavior by using a questionnaire survey. The participants' ideal L2 self, ought-to L2 self, integrativeness, and instrumentality were examined and compared to identify which motivational factor had the most effect on their motivated L2 learning behavior. Among Korean secondary school students, the concept of integrativeness was replaced with the ideal L2 self as a more appropriate concept for understanding Korean secondary school students' L2 learning motivation. As for instrumentality, promotional aspects demonstrated a significant correlation with both the ideal and ought-to L2 selves, whereas preventional aspects showed a relatively high correlation with the ought-to L2 self. The ideal L2 self had the most impact on the motivated behavior, and the ideal L2 self and ought-to L2 self reflected the students' different motivational characteristics. It is suggested that D$\ddot{o}$rnyei's (2005, 2009) L2 motivational self system can be a better psychological model than Gardner's (1985) socio-educational model for understanding Korean secondary school students' L2 learning motivation.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.233-236
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• 2002

This study was conducted to estimate the design flood by the determination of best fitting order for LH-moments of the annual maximum series at fifteen watersheds. Parameters of GEV distribution and flood flows of return period n years were derived by the methods of L, L1, L2, L3 and L4-moments. Frequency analysis of flood flow data generated by Monte Carlo simulation was performed by the methods of L, L1, L2, L3 and L4-moments using GEV distribution. Relative Root Mean Square Error (RRMSE), Relative Bias (RBIAS) and Relative Efficiency (RE) using methods of L, L1, L2, L3 and L4-moments for GEV distribution were computed and compared with those resulting from Monte Carlo simulation. At almost all of the watersheds, the more the order of LH-moments and the return periods increased, the more RE became, while the less RRMSE and RBIAS became. Consequently, design floods for the applied watersheds were derived by the methods of L3 and L4-moments among LH-moments in view of high confidence efficiency.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.78-81
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• 1999

L1 band (1575.42MHz)를 이용한 GPS 수신기의 위치 및 시간 오차는 대략 100 m 와 70 ns 정도로 알려져 있으며, 이 오차의 주원인 중 하나가 위성신호가 대기권을 통과할 때 전리층에서 생기는 전파지연이다. 이러한 전리충의 전파 지연을 정확하게 검출하여 수신기의 위치 오차와 시간 오차를 보정해 주기 위해 사용되는 방식으로서 L1/L2 dual-band를 이용하는 GPS 수신기가 있다. Dual-band GPS 수신기는 한 위성에서 보내는 Ll 밴드 (1575.42MHz) 신호와 L2 밴드 (1227.6MHz) 신호가 각각 전리층을 통과할 때 주파수에 따라 전파 지연 값이 다르다는 것을 이용하여 지연 값을 보정해 주는 원리를 이용한 것이다. 본 논문에서는 Synopsys사의 COSSAP 틀을 이용하여 L1/L2 듀얼 밴드 GPS 수신기의 구조를 상위레벨 시뮬레이션을 통하여 분석하였다.

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.327-332
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• 1999

A highly productive fed-batch fermentation process was developed for the production of L-ornithine by using a new stabilized strain, Breviabcterium ketoglutamicum BK52. Fed-batch cultures with a continuous feeding of the complex medium were conducted on various operating conditions. The optimal concentration of phosphate in the complex medium was 2.1g/L. The optimal feeding rate of L-arginine was 0.028g/L/hr. The optimal feeding point of the complex medium was determined to be at 40 OD of the cell mass. The final L-ornithine concentrations within 64hrs of cultivation in 5 and 50 liter fermenters were 73g/L and 71g/L, respectively. The maximum overall L-ornithine productivity was 1.14g/L/hr which was about 2 times higher than that of the conventional fed-batch culture with intermittent feeding. The overall productivity of the fermentation system is remarkably improved by employing the optimized conditions, and it offers a significant potential for industrial application.

• 한국어류학회지
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• 제12권1호
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• pp.1-13
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• 2000

1986년부터 1999년까지 우리나라의 서해와 남해안을 중심으로 채집된 성대과 어류의 주요 계수, 계측 형질과 형태적 특징들을 분석하여 이들의 분류학적 위치를 재검토하였다. 지금까지 한국산 성대과 어류는 3속 9종으로 보고되었으나, 조사 결과 밀성대속 Pterygotrigla에는 밑성대 P. hemisticta, 성대속 Chelidonichthys에는 성대 C. kumu, 달재속 Lepidotrigla에 는 가시달갱이 L. japonica, 꼬마달재 L. guentheri, 쌍뿔달재 L. alata, 뿔성대 L. kishinouyei, 고지달재 L. kanagashira, 달강어 L. microptera, 히메성대 L. hime, 밀강달이 L. abyssalis 등으로 모두 3속 10종으로 분류되었다. 이 중에는 지금까지 서식이 보고되지 않았던 L. kanagashira를 확인하여, 한국산 미기록종으로 보고하면서, 한국명으로는 "고지달재"라고 명명하였다. 아울러 한국산 성대과 어류 3속 10종에 대한 주요 계수, 계측 형질과 형태적 특징을 기재하면서 각 종에 대한 새로운 분류 검색표를 작성하여 제시하고, 이들의 분류학적 위치와 지리적 분포에 대하여 논의하였다.

• 약학회지
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• 제41권6호
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• pp.698-703
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• 1997

Recently, l-deprenyl (selegiline), a relative new antiparkinson`s drug, has been marketed in Korea. As its metabolites, l-methamphetamine and l-amphetamine, are the enantiomers of illicit drugs,d-methamphetamine and d-amphetamine, a method for analysis of enantiomers of methamphetamine and amphetamine in rat urine was investigated. The optical isomers of methamphetamine and amphetamine were analyzed with the chiral derivatizing reagent (S)-(-)-N-(trifluoroacetyl)-prolyl chloride (l-TFP), which was used to form the diastereomers of methamphetamine and amphetamine. And all diastereomers (l-TFP -l-AM, lTFP-d-AM, l-TFP-l-MA & l-TFP-d-MA) were well resolved by capillary gas chromatography. After administration of 10mg/kg l-deprenyl to rat, l-methamphetamine and l-amphetamine were detected without autoracemization to the d form in all urine samples collected during 24hrs, and the ratios of l-amphetamine/l-methamphetamine were 1.1~3.3. l-Amphetamine was detected in only 3 out of 8 urine samples collected during 24~48hrs where as no l-methamphetamine was detected in all cases.

• Translational and Clinical Pharmacology
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• 제26권3호
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• pp.134-140
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• 2018

This study aimed to develop a UPLC-MS/MS method for determining plasma levels of L-aspartic acid and L-asparagine and the activity of L-asparaginase. L-aspartic acid, L-asparagine, and L-aspartic acid-2,3,3-$d_3$ were extracted from human plasma by protein precipitation with sulfosalicylic acid (30%, v/v). The plasma samples were analyzed using an Imtakt Intrada amino acid analysis column with 25 mM ammonium formate and 0.5% formic acid in acetonitrile as the mobile phase with step gradient method at a flow rate of 0.5 mL/min. The injection volume was $5{\mu}L$, and the total run time was 15 min. Inter- and intra-batch accuracies (%) ranged from 96.62-106.0% for L-aspartic acid and 89.85-104.8%, for L-asparagine, and the coefficient of variation (CV%) did not exceed 7%. The validation results for L-aspartic acid and L-asparagine satisfied the specified criterion, however, the results for L-asparaginase activity assay showed a borderline validity. This study could be a foundation for further development of therapeutic drug monitoring systems using UPLC-MS/MS.