• Food Science and Biotechnology
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• v.14 no.6
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• pp.727-731
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• 2005

Synthesized Ile-Ala-Val-Pro (IAVP) peptide, which has the highest hypocholesterolemic effect among a number of synthesized derivatives of Ile-Ala-Val-Pro-Gly-Glu-Val-Ala (IAVPGEVA) isolated from 11S globulin of soy protein by pepsin digestion, was selected for investigation in the present study. Using a recombinant Syrian hamster 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), we studied in detail the inhibition of this enzyme by IAVP and compared the action of this peptide to that of lovastatin, a known competitive inhibitor of this enzyme. The concentration of IAVP required for 50% inhibition ($IC_{50}$) of HMGR activity in given experimental conditions was $340\;{\mu}M$. Kinetic analysis revealed that the studied peptide is a competitive inhibitor of HMGR with respect to both 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) and nicotinamide adenine dinucleotide phosphate (NADPH), with an equilibrium constant of inhibitor binding ($K_i\;=\;[E][I]/[EI]$) of $61{\pm}1.2\;{\mu}M$ and $157{\pm}4.4\;{\mu}M$, respectively. At the same conditions, $K_i$ and $IC_{50}$ for lovastatin were $2.2{\pm}0.1\;nM$ and 12.5 nM, respectively. Thus, the given peptide interacts with HMGR as a bisubstrate, consequently blocking access of both substrates to the active sites. The achieved results suggest the design of new peptide sequences having a higher relative affinity to binding sites of this enzyme and an enhancement of their hypocholesterolemic properties.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.464-473
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• 2018

Cripto is a small glycosylphosphatidylinositol-anchored signaling protein that can detach from the anchored membrane and stimulate proliferation, migration, differentiation, vascularization, and angiogenesis. In the present study, we demonstrated that Cripto positively affected proliferation and survival of mesenchymal stem cells (MSCs) without affecting multipotency. Cripto also increased expression of phosphorylated janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), 78 kDa glucose-regulated protein (GRP78), c-Myc, and cyclin D1. Notably, treatment with an anti-GRP78 antibody blocked these effects. In addition, pretreatment with STAT3 short interfering RNA (siRNA) inhibited the increase in p-JAK2, c-Myc, cyclin D1, and BCL3 levels caused by Cripto and attenuated the pro-survival action of Cripto on MSCs. We also found that incubation with Cripto protected MSCs from apoptosis caused by hypoxia or $H_2O_2$ exposure, and the level of caspase-3 decreased by the Cripto-induced expression of B-cell lymphoma 3-encoded protein (BCL3). These effects were sensitive to down-regulation of BCL3 expression by BCL3 siRNA. Finally, we showed that Cripto enhanced expression levels of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF). In summary, our results demonstrated that Cripto activated a novel biochemical cascade that potentiated MSC proliferation and survival. This cascade relied on phosphorylation of JAK2 and STAT3 and was regulated by GRP78. Our findings may facilitate clinical applications of MSCs, as these cells may benefit from positive effects of Cripto on their survival and biological properties.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.607-612
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• 2014

The physical properties of mercaptoundecanoic-acid layer formed on gold surfaces, which may affect the distribution of either gold particles adsorbed to the zirconium dioxide surface or vice versa, were investigated. To conduct this investigation, the surface forces were measured between the surfaces with respect to the salt concentration and pH value using atomic force microscope (AFM). The forces were quantitatively converted by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to the surface potential and charge density of surfaces. The converted-value dependence on the salt concentration and pH was described with the law of mass action, and the dependence was consistent with the theoretical prediction. It was found that the mercaptoundecanoic-acid layer had higher values for the surface charge densities and potentials than the $ZrO_2$ surfaces, which may be attributed to the ionized-functional-groups of the mercaptoundecanoic-acid layer.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.14-21
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• 2011

In diesel engines, accurate EGR control is important due to its effect on nitrogen oxide and particulate matter emissions. Conventional EGR control system comprises a PI feedback controller for tracking target air mass flow and a feedforward controller for fast response. Physically, the EGR flow is affected by EGR valve lift and thermodynamic properties of the EGR path, such as pressures and temperatures. However, the conventional feedforward control output is indirectly derived from engine operating conditions, such as engine rotational speed and fuel injection quantity. Accordingly, the conventional feedforward control action counteracts the feedback controller in certain operating conditions. In order to improve this disadvantage, in this study, we proposed feedforward EGR control algorithm based on a physical model of the EGR system. The proposed EGR control strategy was validated with a 3.0 liter common rail direct injection diesel engine equipped with a DC motor type EGR valve.

• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.61-81
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• 2004

What is the most important in articles of food is hygienic safety. Because food Is the most common thing in our everyday life, however, the importance of its hygienic safety and other many problems caused by food may be easily neglected. What is more, food is can be dangerous as much as it is directly related to human life and accidents from the same cause may have different effects on the victims according to physical and environmental differences of individuals. Thus PL action for food requires more thorough prevention and measure. Korea has been enforcing 'the Product Liability Act' since the 1/sup 1st/ of July 2002. Product Liability (PL) is liability of the manufacturer or the seller of a product to compensate for the death or injury of consumers or the loss of properties caused by the defect of the product. This study surveyed consumers' response to and the effects of the enforcement of the Product Liability Act, investigated how consumers perceived the importance of food safety and the risk of defective food based on PL standards and their experience in damage by food through a questionnaire survey, and analyzed collected data through empirical analyses (reliability analysis, factorial analysis, regression analysis and ANOVA t-test) using SPSS 10.0. Based on the results of analysis, the researcher proposed strategies for coping with the Product Liability Act in the food industry.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.1
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• pp.15-23
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• 2003

Cellular redox state is known to be perturbed during ischemia and that $Ca^{2+}$ and $K^2$ channels have been shown to have functional thiol groups. In this study, the properties of thiol redox modulation of the ATP-sensitive $K^2$ ($K_{ATP}$) channel were examined in rabbit ventricular myocytes. Rabbit ventricular myocytes were isolated using a Langendorff column for coronary perfusion and collagenase. Single-channel currents were measured in excised membrane patch configuration of patch-clamp technique. The thiol oxidizing agent 5,5'-dithio-bis-(2-nitro-benzoic acid) (DTNB) inhibited the channel activity, and the inhibitory effect of DTNB was reversed by dithiothreitol (disulfide reducing agent; DTT). DTT itself did not have any effect on the channel activity. However, in the patches excised from the metabolically compromised cells, DTT increased the channel activity. DTT had no effect on the inhibitory action by ATP, showing that thiol oxidation was not involved in the blocking mechanism of ATP. There were no statistical difference in the single channel conductance for the oxidized and reduced states of the channel. Analysis of the open and closed time distributions showed that DTNB had no effect on open and closed time distributions shorter than 4 ms. On the other hand, DTNB decreased the life time of bursts and increased the interburst interval. N-ethylmaleimide (NEM), a substance that reacts with thiol groups of cystein residues in proteins, induced irreversible closure of the channel. The thiol oxidizing agents (DTNB, NEM) inhibited of the $K_{ATP}$ channel only, when added to the cytoplasmic side. The results suggested that metabolism-induced changes in the thiol redox can also modulate $K_{ATP}$ channel activity and that a modulatory site of thiol redox may be located on the cytoplasmic side of the $K_{ATP}$ channel in rabbit ventricular myocytes.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.215-218
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• 2004

Dextrans make up a class of polysaccharides that are D-glucans of various structures with contiguous $\alpha$-1longrightarrow6 ~6 glycosidic linkages in the main chains and $\alpha$-1longrightarrow2, $\alpha$-1longrightarrow3, or $\alpha$-1longrightarrow4 branch glycosidic linkages, depending on the specificity of the particular dextransucrase. Glucansucrases that catalyze glucans synthesis from sucrose. When other carbohydrates, in addition to sucrose, are present in the enzyme digest, the enzyme transfers glucose to the carbohydrate acceptors in the secondary reaction that diverts some of the glucose from incorporation into glucan. Many carbohydrate acceptors have been recognized and the products that result are dependent on the particular enzyme and the structure of the particular acceptor. Because of these unique catalytic characteristics, various dextransucrases have many important industrial and medical uses. To improve the understanding of their action mode and extend their applications, this study describes mechanism of glucan synthesis and potential industrial uses of dextransucrases, and our recent findings on the structural, functional organization and directed evolution of the glucansucrases to offer for designing glucansucrases with improved properties.

• Journal of KIISE:Software and Applications
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• v.26 no.12
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• pp.1428-1444
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• 1999

MSC는 ITU에 의해 표준화된, 병행 시스템의 명세를 기술하기 위한 그래픽 형태와 텍스트 형태를 제공하는 언어로서 실시간 시스템 특히 통신 교환 시스템의 특성을 기술하기 위해 자주 사용된다. 통신 시스템이 제대로 동작함을 보이기 위해서는 정형적인 방법을 사용하여 시스템 행위를 검증할 필요가 있다. 통신 소프트웨어를 검증하는 방법 중 하나의 방법으로 유한 상태를 기반으로 하는 방법이 있다. 유한 상태를 기반으로 하는 방법에서는 먼저 시스템 명세에 해당하는 전체 상태 전이 그래프를 생성한 후 이를 바탕으로 model-checking 등의 방법을 사용하여 시스템의 특성을 검증한다. 본 논문에서는 MSC로 기술된 통신 소프트웨어 명세로부터 전체 상태 전이 그래프를 생성하는 방법에 초점을 맞추었다. 시스템 명세에 해당하는 상태 전이 그래프를 생성하기 위해 보다 직관적으로 MSC의 의미론을 표현할 수 있고, 또한 쉽게 전체 상태 전이 그래프를 생성할 수 있는 행위 종속 그래프를 제안하였다. MSC 명세는 일단 행위 종속 그래프로 변환이 되고 이 행위 종속 그래프를 이용하여 전체 상태 전이 그래프가 생성된다.Abstract Message Sequence Chart (MSC) standardized by International Telecommunication Union is a graphical and textual language for describing the specification of concurrent systems. It is frequently used both formally and informally for specifying the behavior of real-time systems, in particular telecommunication switching systems. To ensure that a communication system operates properly, the verification process showing the correctness of system's behavior formally is necessary. One of the verification methods is a finite-state method. In the finite-state method, the global state transition graph (GSTG) is constructed and then safety and liveness properties of systems are verified through a well-known method such as model checking. In this paper, we forcus on the construction of GSTG from the specifications of telecommunication software written in MSC. We suggest Action Dependency Graph (ADG) which can present the semantics of MSC intuitively and also provide a GSTG construction method from ADG. MSC specifications are translated to ADGs and, in turns, the GSTGs are constructed by using these ADGs.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.496-503
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• 2018

Background: Korean ginseng (Panax ginseng) plays an anti-inflammatory role in a variety of inflammatory diseases such as gastritis, hepatitis, and colitis. However, inflammation-regulatory activity of the calyx of the P. ginseng berry has not been thoroughly evaluated. To understand whether the calyx portion of the P. ginseng berry is able to ameliorate inflammatory processes, an ethanolic extract of P. ginseng berry calyx (Pg-C-EE) was prepared, and lipopolysaccharide-activated macrophages and HEK293 cells transfected with inflammation-regulatory proteins were used to test the anti-inflammatory action of Pg-C-EE. Methods: The ginsenoside contents of Pg-C-EE were analyzed by HPLC. Suppressive activity of Pg-C-EE on NO production, inflammatory gene expression, transcriptional activation, and inflammation signaling events were examined using the Griess assay, reverse transcription-polymerization chain reaction, luciferase activity reporter gene assay, and immunoblotting analysis. Results: Pg-C-EE reduced NO production and diminished mRNA expression of inflammatory genes such as cyclooxygenase-2, inducible NO synthase, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. This extract suppressed luciferase activity induced only by nuclear factor-${\kappa}B$. Interestingly, immunoblotting analysis results demonstrated that Pg-C-EE reduced the activities of protein kinase B (AKT)1 and AKT2. Conclusion: These results suggest that Pg-C-EE may have nuclear-factor-${\kappa}B$-targeted anti-inflammatory properties through suppression of AKT. The calyx of the P. ginseng berry is an underused part of the ginseng plant, and development of calyx-derived extracts may be useful for treatment of inflammatory diseases.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.155-164
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• 2009

Digital Content Marketplace based on Interactive Media is defmed as the marketplace for content service between contents supplier and consumer through iDTV environment. This Marketplace is increasing interest to u-Life service with Digital Environment. To Interactive Media, it can contribute to enhance its effectiveness by developing various contents and service model in the initial phase of broadcasting-communication convergence. This study designed metadata using Digital Content marketplace based on Interactive Media. Specially the matadata designing include recommendation-tag for supply supplementary content. It can support self-directed action. Through basic metadata with weight value, it is designed to support supplementary content customer to want on the marketplace. Recommendation-System can be built by many method and to recommend the service content including explicit properties using collaborative filtering method can solve limitations in existing content recommendation.