• Journal of the Korean Chemical Society
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• v.38 no.3
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• pp.221-223
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• 1994

We tried to apply the linear solvation energy comparison method to solute retention in normal phase liquid chromatography. Correlation coefficients of regression of lnk' collected in a fixed eluent against solute polarity indices have proven to be lower than those obtained from reversed phase liquid chromatography data. This event can be attributed to complexity of solute retention process in normal phase liquid chromatography. We concluded from the regression results that each specific polarity of the stationary phase is greater than that of the mobile phase and that the difference in each polarity between the stationary phase and the mobile phase decreases as the volume fraction(${\phi}$) of the more polar solvent in the mobile phase increases. Correlations of lnk' of a single solute against solvent polarity indices have proven to be meaningless owing to covariance among the solvent polarity indices. Instead, a good linear relationship between lnk' and solvent ${\pi}^*$ was observed, and its linearity is better than that between lnk' and ${\phi}$.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.117-125
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• 2016

Nitrite and dimethylamine (DMA) are the immediate precursors of carcinogenic N-nitrosodimethylamine (NDMA). This study investigated the effects of nitrite and nitrate contents in Chinese cabbage on changes in NDMA, nitrite, nitrate, and DMA contents during storage of kimchi. Contents of nitrite in Chinese cabbage 1 (HNC), Chinese cabbage 2 (MNC), and Chinese cabbage 3 (LNC) were $47.54{\pm}1.07$, $10.12{\pm}0.31$, and $6.10{\pm}0.09mg/kg$, respectively. Kimchi were assigned to one of the following three groups: kimchi used HNC (HNK), kimchi used MNC (MNK), and kimchi used LNC (LNK). HNK had higher levels of nitrite and nitrate than those in MNK and LNK after storage for 10 days and 20 days. DMA and NDMA contents decreased in all kimchi during the storage period. HNK had higher NDMA content than LNK until 20 days of storage. These results suggest that the contents of nitrite and nitrate in Chinese cabbage have significant effects on the formation of NDMA in kimchi.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.173-174
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• 2023

이 논문은 북한 해킹 그룹이 최근 유포하고 있는 악성코드 CHM 과 RokRAT 에 대해 연구하고 대응하는 목적으로 작성되었다. 악성코드 CHM 은 chm 파일 실행 시 도움말 창을 생성하여 내부 악성 스크립트가 동작하는 방식이다. 악성코드 RokRAT 은 윈도우에 기본 탑재된 lnk 파일을 pdf 아이콘으로 위장하여 사람들에게 유포하는 방식을 사용하였다. 이는 다양한 형식의 파일을 통해 유포되는 만큼 사용자가 보안 위협에 대한 경각심을 가지고 스스로 예방하고 대처할 수 있어야 한다는 결론을 내리고 있다.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.