• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1808-1816
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• 2016

As a scaffolding subunit of the PIK3C3/VPS34 complex, Beclin 1 recruits a variety of proteins to class III phosphatidylinositol-3-kinase (VPS34), resulting in the formation of a distinct PIK3C3/VPS34 complex with a specific function. Therefore, the investigation of a number of Beclin 1 domains required for the protein-protein interactions will provide important clues to understand the PIK3C3/VPS34 complex, of which Beclin1-VPS34 interaction is the core unit. In the present study, we have designed a bacterial overexpression system for the Beclin 1 domain corresponding to VPS34 binding (Vps34-BD) and set up the denaturing purification protocol due to the massive aggregation of Vps34-BD in Escherichia coli. The expression and purification conditions determined in this study successfully provided soluble and functional Vps34-BD.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(3)
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• pp.31-34
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• 2000

Genetic Algorithm is well known as the efficient algorithm which can solve a difficult optimization problem. Recently, there has been increasing interest in applying genetic algorithm to problem related to network design. In this paper, we propose a two-step genetic algorithm for designing a optimum virtual path network(VPN) for a given physical network and traffic demand. The first step is a routing step in which a route is found between every node pair in the network. In the second step, paths are assigned as VPs so as to minimize the total number of VPs configured, the number of VPs carried by a link, and the VP hopcount. We study the performance of the propose algorithm through simulation. The result shows that the VPN generated by the proposed algorithm is good in minimizing the number of VPs configured, the load on a link, and the VP hopcount.

• 대한화장품학회지
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• 제45권4호
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• pp.373-380
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• 2019

얼굴과 하박내측의 피부는 경피수분손실량(TEWL), 피부 수분량, 탄력 등에서 많은 차이를 보이고 있다. 특히, 이전 연구 결과에서 얼굴피부와 하박내측 피부는 수화(hydrating) 과정에 따른 탄력특성의 차이를 보여 주었다. 이에 본 연구에서는 신체부위에 따른 피부특성 차이는 각 신체부위를 구성하고 있는 각질세포 특성과 연관성이 있을 것이라는 가정하에 atomic force microscopy (AFM)을 이용하여 각질세포 표면 특성을 비교 연구하였다. 각질세포 표면의 거칠기(roughness)와 villus-like projections (VPs)을 이용하여 비교 평가 하였다. 더 나아가 얼굴피부, 하박내측, 입술 피부의 각질세포 표면을 정성적으로 비교해 보았다. 각질세포는 8명의 피험자의 얼굴과 하박내측 피부에서 tape-stripping을 이용하여 채취하여, AFM을 이용하여 40 ㎛ × 40 ㎛ 크기로 각질세포의 아랫면 표면 특성(bottom surface of corneocyte)을 측정하였다. 그 결과, 얼굴 각질세포 아랫면 표면 거칠기는 388.34 ± 86.189 nm이었고, 하박내측 각질세포 아랫면 표면 거칠기는 662.27 ± 224.257 nm로 하박내측 각질세포가 얼굴 각질세포보다 더 거친 표면 특성임을 확인하였다(p < 0.001). 관찰된 VPs의 양을 비교해보면, 입술 각질세포가 가장 많았고, 그 다음이 얼굴 각질세포이며, 하박내측 각질세포는 낮은 수준이었다. 이러한 결과를 통해 볼때, 각질세포 표면 특성이 얼굴과 하박내측 피부 사이에 보이는 특성 차이에 어느 정도 관여하고 있음을 확인할 수 있었으며, VPs는 부위별 피부 특성 연구에 유용한 parameter가 될 수 있는 가능성도 확인할 수 있었다. 그리고, AFM은 각질세포 표면의 미세한 구조적 차이를 비교 연구하는데 매우 유용한 기기임을 알 수 있었다. 향후 조금 더 많은 연구가 진행된다면 각질세포에 대한 새로운 화장품 효능 평가법이 개발될 것으로 사료된다.

• IMMUNE NETWORK
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• 제21권5호
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• pp.37.1-37.17
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• 2021

Hepatitis B virus X (HBx) protein has been reported as a key protein regulating the pathogenesis of HBV-induced hepatocellular carcinoma (HCC). Recent evidence has shown that HBx is implicated in the activation of autophagy in hepatic cells. Nevertheless, the precise molecular and cellular mechanism by which HBx induces autophagy is still controversial. Herein, we investigated the molecular and cellular mechanism by which HBx is involved in the TRAF6-BECN1-Bcl-2 signaling for the regulation of autophagy in response to TLR4 stimulation, therefore influencing the HCC progression. HBx interacts with BECN1 (Beclin 1) and inhibits the association of the BECN1-Bcl-2 complex, which is known to prevent the assembly of the pre-autophagosomal structure. Furthermore, HBx enhances the interaction between VPS34 and TRAF6-BECN1 complex, increases the ubiquitination of BECN1, and subsequently enhances autophagy induction in response to LPS stimulation. To verify the functional role of HBx in liver cancer progression, we utilized different HCC cell lines, HepG2, SK-Hep-1, and SNU-761. HBx-expressing HepG2 cells exhibited enhanced cell migration, invasion, and cell mobility in response to LPS stimulation compared to those of control HepG2 cells. These results were consistently observed in HBx-expressed SK-Hep-1 and HBx-expressed SNU-761 cells. Taken together, our findings suggest that HBx positively regulates the induction of autophagy through the inhibition of the BECN1-Bcl-2 complex and enhancement of the TRAF6-BECN1-VPS34 complex, leading to enhance liver cancer migration and invasion.

• 대한치과보철학회지
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• 제34권2호
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• pp.349-362
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• 1996

To determine the factors to affect on stone surface porosities produced from hydrogen gas of additional silicone, both putty and syringe type of 7 commercially different additional silicone impression materials(Blend-A-Scon, Correct VPS, Exaflex, Express, Extrude, Provil, Reprosil) were chosen and NewFujirock(GC) was poured into the impressions of detail-reproducing test block at 1, 15, 30, 45, 60 minutes after the impression materials had set and 4 specimens were made for each pouring time, each type of impression material, and each consisency and So, 280 specimens were made in total. The number of surface porosities of same area($2826 mm^2$) which were typically caused by hydrogen gas using the stereoscope(X 7.5) by two observers. Comparison of putty-syringe type and among the impression materials are tested by Kruscal-Wallis method and Mann-Whitney method(p<0.05). The results are as follows. 1. The number of porosities decreased as the pouring time of stone was delayed on both putty and syringe type of additional silicone materials. 2. The putty type significantly produced more porosities than syringe type except for the group of Reprosil.(p<0.05). 3. In case of putty type, the number of porosities increased as following order. Reprosil / Blend-A-Scon and Provil / Correct VPS and Extrude / Express and Exaflex. 4. In case of syringe type, Blend-A-Scon and Extrude produced no porosity and Exaflex and Provil at 30 minites, but Express produced porosities even at 60 minutes and the most. Additional silicone impression material releases hydrogen gas, and that fact can make the resulting die stone model useless. So, to minimize these adverse effects, it is desirable not to expose putty type of additional silicone on critical impression surface because putty type has a tendency to produce more porosities than syringe type. And it is important to have sufficient time before pouring the stone on impression because porosities produce less as time passes after setting of impression material. Also, there are differences among 7 additional silicone impression materials, so it is desirable to choose adequate brand of additional silicone for good laboratory work.

• BMB Reports
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• 제44권9호
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• pp.601-606
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• 2011

HMGB1 is associated with human cancers and is an activator of autophagy which mediates chemotherapy resistance. We here show that the mRNA levels of HMGB1 are high in leukemia cells and it is involved in the progression of childhood chronic myeloid leukemia (CML). HMGB1 decreases the sensitivity of human myeloid leukemia cells K562 to anti-cancer drug induced death through up-regulating the autophagy pathway, which is confirmed by the observation with an increase in fusion of autophagosomes and autophagolysosomes. When overexpressing HMGB1, both mRNA levels of Beclin-1, VSP34 and UVRAG which are key genes involved in mammalian autophagy and protein levels of p-Bcl-2 and LC3-II are increased. Luciferase assays document that over-expression of HMGB1 increases the transcriptional activity of JNK and ERK, which may be silenced by siRNA. The results suggest that HMGB1 regulates JNK and ERK required for autophagy, which provides a potential drug target for therapeutic interventions in childhood CML.

• International Journal of Oral Biology
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• 제41권1호
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• pp.45-51
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• 2016

Rutin (3,3',4',5,7-pentahydroxyflavone-3-rhamnoglucoside) is a bioactive flavonoid from the plant kingdom. Rutin has been studied as potential anticancer agent due to its wide range of pharmacological properties including antioxidative, anti-inflammatory and anticancer. Autophagy is a conserved intracellular catabolic pathway to maintain cell homeostasis by formation of autophagosome. Processing of autophagy involves various molecules including ULK1 protein kinase complex, Beclin-1-Vps34 lipid kinase complex, ATG5, ATG12, and LC3 (light chain 3). Cargo-carried autophagosomes fuse with lysosomes resulting in autophagolysosome to eliminate vesicles and degrade cargo. However, the actions of rutin on autophagy are not clearly understood. In this study, we analyzed the effect of rutin on autophagy and inflammation in cancer cell lines. Interestingly, rutin induced autophagy in leukemia (THP-1), oral (CA9-22), and lung (A549) cell lines. TNF-${\alpha}$, key modulator of inflammation, was upregulated by inhibition of rutin-induced autophagy. Taken together, these data indicated that rutin induced autophagy and consequently suppressed TNF-${\alpha}$ production.

• 대한치과보철학회지
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• 제34권2호
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• pp.266-276
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• 1996

Numerous factors are known to affect the accuracy of elastomeric impression materials. Factor often overlooked is the quality of the bond between putty and wash during corrective reline impression technique. The putty-wash bond strength must be strong enough to over-come the local stress at putty-wash interface. It is not always possible to avoid saliva contamination in making corrective wash impres-sion. And putty preliminary impression material con be used as a template for provisional restoration. Human saliva and the residual monomer of autopolymerizing acrylic resin are thought to affect the bond strength and the failure type. This study examined the effect of contaminants like human saliva, and residual resin monomer on the putty-wash bond strength and the effectiveness of treatment. 1. Of the tested three brands of Vinyl Polysiloxane impession meterial, Express Exhibited the greatest bond strength followed by Eamix and Perfect showed the lowest putty-wah bond strength. 2. Coating the putty substrates with human saliva did not produce decreased failure load in all the breands of Vinyl Polysiloxane impression meterail. 3. Of the three brands of VPS impression material that were exposed to methhylmethacry-late resin(Jet), only the putty-wash bond strength of the Perfect group diminished signifi-cantly. Moreover, all the specimens from group C of Perfect exhibited adhesive failure. 4. Exposing the substrates to ethylmethacrylate resin(SNAP. diminished the putty-wash bond strength significantly. With Perfect and Examix, failure occurred cohesively through the light-body, whereas with Express, failure occurred adhesive-cohesively. 5. Removing approximately 1mm thickness of the contaminated putty interface was the most effective treatment in countering the undesirable effect caused by residual resin monomer. The putty-wash bond strength of the groups that were treated with 1mm even putty reduction was not significantly different from those of control groups. With Perfect and Examix, cleaning the specimens with gauze soaked in 70% isopropyl alcohol increased the putty-wash bond strength, but was not as effective as 1mm even reduction of contaminated putty substrates. With Express, 70% isoproryl alcohol treatment exhibi0ted comparable putty-wash bond strength to that of control group.