• Journal of Microbiology
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• v.44 no.2
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• pp.192-199
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• 2006

Pseudomonas putida KL47 is a natural isolate that assimilates benzene, 1-alkylbenzene $(C_1-C_4)$, biphenyl, p-cumate, and p-cymene. The genetic background of strain KL47 underlying the broad range of growth substrates was examined. It was found that the cym and cmt operons are constitutively expressed due to a lack of the cymR gene, and the tod operon is still inducible by toluene and biphenyl. The entire array of gene clusters responsible for the catabolism of toluene and p-cymene/p-cumate has been cloned in a cosmid vector, pLAFR3, and were named pEK6 and pEK27, respectively. The two inserts overlap one another and the nucleotide sequence (42,505 bp) comprising the cym, cmt, and tod operons and its flanking genes in KL47 are almost identical (>99 %) to those of P. putida F1. In the cloned DNA fragment, two genes with unknown functions, labeled cymZ and cmtR, were newly identified and show high sequence homology to dienelactone hydrolase and CymR proteins, respectively. The cmtR gene was identified in the place of the cmtI gene of previous annotation. Western blot analysis showed that, in strains F1 and KL47, the todT gene is not expressed during growth on Luria Bertani medium. In minimal basal salt medium, expression of the todT gene is inducible by toluene, but not by biphenyl in strain F1; however, it is constantly expressed in strain KL47, indicating that high levels of expression of the todST genes with one amino acid substitution in TodS might provide strain KL47 with a means of adaptation of the tod catabolic operon to various aromatic hydrocarbons.

• Journal of ILASS-Korea
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• v.9 no.4
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• pp.46-52
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• 2004

An LPG engine (KL6i) for heavy duty vehicle has been developed using liquid phase LPG injection (LPLi) system, which has regarded as one of next generation LPG fuel supply systems. For the KL6i engine, lean burn technology was introduced to minimize the thermal loading and NOx emissions due to an increase of the engine power. In this work, injection timing and piston bowl shape were investigated for the stabilization of lean burn characteristics. Experimental results reveals that fuel stratification induced by these parameters is most effective strategy to extend lean combustion limit in the LPLi system.

• YAKHAK HOEJI
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• v.57 no.6
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• pp.426-431
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• 2013

In our previous studies, 6-hydroxy-7-methoxychroman-2-carboxylic acid N-phenylamide (KL-1156) was identified as a good inhibitor of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation. In continuation of our study, we describe the structure-activity relationship of chroman derivatives containing N-arylalkyl groups and their NF-${\kappa}B$ inhibitory activities. In addition, inhibitory effects of cell proliferation are evaluated against human cancer cell lines (NCI-H23 and PC-3). The most active compounds 3i and 3j contained diphenylethyl and diphenylpropyl side chain on amide nitrogen.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.537-554
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• 2006

Water levels of thermal groundwater ($>30^{\circ}C$) were recorded from March 2002 to June 2006 at several monitoring wells within the Yuseong spa area. Using these data, we elucidated the long-term cyclic fluctuations of thermal groundwater levels with 1 year period. We also observed a noticeable water level variation with periods of 0.5, 1 and 7 days in most monitoring wells, which indicates relatively good hydraulic connectivity within the main hotspring area. By comparing water level variations among several wells, we found out that E-W and N-S trending geological structures should be an important control factor for emplacement and flow of thermal groundwater in the study area. It may be also inferred that geothermal source is highly associated with the hydraulic connectivity of aquifers at the Yuseong spa area.

• Preventive Nutrition and Food Science
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• v.20 no.3
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• pp.169-175
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• 2015

Shinseoncho and kale were made into green vegetable juices by building block [shinsenocho branch (SB), shinsenocho leaf (SL), kale branch (KB), and kale leaf (KL)]. Fluctuations in their phenolic contents and antioxidant capacities were analyzed during refrigerated storage at $4^{\circ}C$ for 28 days. Total polyphenolic contents of leaf parts showed a decreasing tendency after 4 days (SL) or 7 days (KL), whereas branch parts showed fluctuating values during the entire storage period. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity was rapidly decreased in SB and in SL at 28 days (P<0.001), whereas KL showed a slightly increasing tendency after 14 days. For the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, SL showed a sharp fall at 28 days (P<0.001), and KL showed a decreasing tendency after 14 days (P<0.001). SB showed a steady decrease during the entire storage period and KB indicated a nearly zero (0.97%) at 28 days. Pearson's coefficients for the correlation between antioxidant capacities measured by the ABTS and DPPH assays, and the total polyphenolic contents were determined. The results showed that the ABTS assay (r=0.934, P<0.001) was more strongly positively correlated with the total phenolic contents than the DPPH assay (r=0.630, P<0.001). In conclusion, when considering all building blocks, green vegetable juices, including kale and shinseoncho may have kept antioxidant capacities for up to 14 days under refrigeration, and the ABTS assay better reflects a positive correlation with the total phenolic contents when compared to the DPPH assay.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.604-607
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• 2012

Solid base catalysts for biodiesel production were synthesized by impregnating basic metal species on two support materials with large specific surface area : zeolite and pyrolysis char. KL zeolite and Undaria pinnatifida char were impregnated with KOH aqueous solution and calcium nitrate solution, respectively, to enhance the basic strength. The catalysts synthesized were characterized using Hammett indicators and $CO_2$-TPD analysis. Biodiesel was produced using soybean oil and methanol over the catalysts synthesized. The content of fatty acid methyl esters was measured to evaluate the catalytic activity. Generally, the catalytic activity increased with increasing quantity of basic metal impregnated but impregnation of excessive amount of metal could cause reduction in the activity.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.609-619
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• 2009

SWAT-K model is a modified version of the original SWAT, and is known to more accurately estimate the streamflows and pollutant loadings in Korean watersheds. In this study, its hydrological components were compared with those of HSPF in order to analyse the differences in total runoff including evapotranspiration(ET), surface flow, lateral flow and groundwater flow from the Chungju Dam watershed during $2000{\sim}2006$. Averaged annual runoff with SWAT-K overestimated by 1%, and HSPF underestimated it by 3% than observed runoff. Determination coefficients($R^2$) for observed and simulated daily streamflows by both the models were relatively good(0.80 by SWAT-K and 0.82 by HSPF). Potential ET and actual ET by HSPF were lower in winter, but similar or higher than those by SWAT-K. And though there were some differences in lateral and groundwater flows by two models because of the differences in hydrological algorithms, the results were to be reasonable. From the results, it was suggested that we should utilize a proper model considering the characteristic of study area and purposes of the model application because the simulated results from same input data could be different with models used. Also we should develop a novel model appropriate to Korean watersheds by enhancing limitations of the existing models in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.6
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• pp.1133-1146
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• 2011

Cognitive radio (CR) is considered one of the most promising next-generation communication systems; it has the ability to sense and make use of vacant channels that are unused by licensed users. Reliable detection of the licensed users' signals is an essential element for a CR network. Cooperative spectrum sensing (CSS) is able to offer better sensing performance as compared to individual sensing. The presence of malicious users who falsify sensing data can severely degrade the sensing performance of the CSS scheme. In this paper, we investigate a secure CSS scheme, based on the Kullback-Leibler Divergence (KL-divergence) theory, in order to identify malicious users and mitigate their harmful effect on the sensing performance of CSS in a CR network. The simulation results prove the effectiveness of the proposed scheme.

• YAKHAK HOEJI
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• v.54 no.3
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• pp.200-204
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• 2010

Nuclear factor-${\kappa}B$ (NF-${\kappa}B$) plays critical roles in physiological and pathological processes such as immune function, cellular growth, homeostasis, apoptosis, and inflammation. As part of our ongoing efforts to develop novel NF-${\kappa}B$ inhibitory agents, we reported that KL-1156 (6-hydroxy-7-methoxychroman-2-carboxylic acid phenylamide) exhibited potent inhibitory activity of NF-${\kappa}B$. For further structure-activity relationship, a series of 7-aryloxy-chroman-2-carboxylamide derivatives were synthesized to explore their inhibitory activities of NF-${\kappa}B$.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1014-1019
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• 2004

Effects of kimchi lactic acid powder (KL) on weight reduction and lipid-lowering activities were studied using rats fed high fat diet. Spraque Dawley (40 rats) were fed 20% (w/w) high fat diet far 8 weeks to induce obesity and divided equally into normal diet (ND), high fat diet (HFD), and 10 and 20% KL-added groups. Body weight of HFD was 150% (p<0.01) of ND, while those of HFK10 and HFK20 decreased by 13 and 15% compared to HFD, respectively (p<0.01). Amounts of visceral fats for HFK10 and HFK20 were decreased by 42 and 48% compared to that of HFD (198% of ND), respectively (p<0.01). B had greater effect on reducing visceral fats than body weight. Plasma triglyceride (155%), cholesterol (129%), and LDL (161%) concentrations of HFD, which had been significantly increased compared to ND, dropped by 26, 9, and 8% (p<0.01) in HFK10, and 35, 17, and 33% (p<0.05) in HFK20, respectively. Decreased HDL by high fat diet was re-increased by KL supplementation. KL showed lipid-lowering and liver-protecting effects in liver possibly by interrupting lipid absorption in the intestine either by absorbing lipids in their cell walls or degrading them rapidly. Increased excretion of TG and cholesterol in feces of HFK10 and HFK20 indicates KL might have similar role to dietary fiber.