• Journal of Microbiology and Biotechnology
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• v.18 no.2
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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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• v.10 no.3
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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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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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.

• English Language & Literature Teaching
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• v.18 no.1
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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.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.78-81
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• 1999

The position and time errors of a conventional L1-band GPS receiver (1575.42MHz) are known to be about 100 m and 70 ns, respectively. These errors are mainly due to the propagation delay of GPS satellite signals through ionosphere. Various L1/L2 dual-band GPS receivers are normally used to compensate for those position and time errors by detecting an accurate propagation delay. These receivers detect the propagation delay difference between the L1 and L2 signals based on the fact that the propagation delay through ionosphere is dependent on frequency and, from which, calculate an accurate propagation delay of the GPS signals through ionosphere. In this paper, we analyzed the architecture of a L1/L2 dual-band CPS receiver by high-level simulations with Synopsys's COSSAP Tool.

• Microbiology and Biotechnology Letters
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• v.27 no.4
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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.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.1-13
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• 2000

The taxonomic review of the family Triglidae was made based on the specimens collected from the south-western coasts of Korea from 1986 to 1999. The family Triglidae from Korea was classified into 10 species belonging to 3 genera: Pterygotrigla hemisticta, Chelidonichthys kumu, Lepidotrigla, japonica. L. guentheri, L. alata, L. kishinouyei, L. kanagashira, L. microptera, L. hime and L. abyssalis. Of them, L. kanagashira was reported for the first time in South Sea of Korea. A key to species of the family Triglidae from Korea was provided, with description of their morphological characteristics and their distribution.

• YAKHAK HOEJI
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• v.41 no.6
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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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• v.26 no.3
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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.