• Journal of Life Science
• /
• v.26 no.12
• /
• pp.1367-1375
• /
• 2016

Cilostazol is known to be a selective inhibitor of phosphodiesterase III and is generally used to treat stroke. Our previous findings showed that cilostazol enhanced capillary density through angiogenesis after focal cerebral ischemia. Angiogenesis is an important physiological process for promoting revascularization to overcome tissue ischemia. It is a multistep process consisting of endothelial cell proliferation, migration, and tubular structure formation. Here, we examined the modulatory effect of cilostazol at each step of the angiogenic mechanism by using human brain microvascular endothelial cells (HBMECs). We found that cilostazol increased the migration of HBMECs in a dose-dependent manner. However, it did not enhance HBMEC proliferation and capillary-like tube formation. We used a cDNA microarray to analyze the mechanisms of cilostazol in cell migration. We picked five candidate genes that were potentially related to cell migration, and we confirmed the gene expression levels by real-time PCR. The genes phosphoserine aminotransferase 1 (PSAT1) and CCAAT/enhancer binding protein ${\beta}$ ($C/EBP{\beta}$) were up-regulated. The genes tissue factor pathway inhibitor 2 (TFPI2), retinoic acid receptor responder 1 (RARRES1), and RARRES3 were down-regulated. Our observations suggest that cilostazol can promote angiogenesis by promoting endothelial migration. Understanding the cilostazol-modulated regulatory mechanisms in brain endothelial cells may help stimulate blood vessel formation for the treatment of ischemic diseases.

• Journal of Periodontal and Implant Science
• /
• v.42 no.6
• /
• pp.185-195
• /
• 2012

Purpose: (-)-epigallocatechin-3-gallate (EGCG) has been reported to exert anti-inflammatory and antibacterial effects in periodontitis. However, its exact mechanism of action has yet to be determined. The present in vitro study evaluated the anti-in-flammatory effects of EGCG on human periodontal ligament fibroblasts (hPDLFs) and human periodontal ligament stem cells (hPDLSCs) affected by bacterial lipopolysaccharide (LPS) extracted from Porphyromonas gingivalis. Methods: hPDLFs and hPDLSCs were extracted from healthy young adults and were treated with EGCG and/or P. gingivalis LPS. After 1, 3, 5, and 7 days from treatment, cytotoxic and proliferative effects were evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and bromodeoxyuridine assay, respectively. And then, the gene expressions of hPDLFs and hPDLSCs were observed for interleukin (IL)-$1{\beta}$, IL-6, tumor necrosis factor (TNF)-${\alpha}$, osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), and RANKL/OPG using real-time polymerase chain reaction (PCR) at 0, 6, 24, and 48 hours after treatment. The experiments were performed with the following groups for hPDLFs and hPDLSCs; 1) No treat, 2) EGCG alone, 3) P. gingivalis LPS alone, 4) EGCG+P. gingivalis LPS. Results: The 20 ${\mu}M$ of EGCG and 20 ${\mu}g/mL$ of P. gingivalis LPS had the lowest cytotoxic effects, so those concentrations were used for further experiments. The proliferations of hPDLFs and hPDLSCs increased in all groups, though the 'EGCG alone' showed less increase. In real-time PCR, the hPDLFs and hPDLSCs of 'EGCG alone' showed similar gene expressions to those cells of 'no treat'. The gene expressions of 'P. gingivalis LPS alone' in both hPDLFs and hPDLSCs were highly increased at 6 hours for IL-$1{\beta}$, IL-6, TNF-${\alpha}$, RANKL, and RANKL/OPG, except the RANKL/OPG in hPDLSCs. However, those increased gene expressions were down-regulated in 'EGCG+P. gingivalis LPS' by the additional treatment of EGCG. Conclusions: Our results demonstrate that EGCG could exert an anti-inflammatory effect in hPDLFs and hPDLSCs against a major pathogen of periodontitis, P. gingivalis LPS.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.4
• /
• pp.514-520
• /
• 2019

This study investigated the improved lipid metabolism effect of 3T3-L1 cells induced by adipocytes using the dichloromethane (DCM) fraction in the organic solvent extract of Wassong (Orostachys japonicus). To confirm the cell cytotoxicity, each of 6 fractions of organic solvent extracts (EtOH, Hexane, DCM, EtOAc, BuOH, and H₂O) was examined using MTS assay. As a result, it was confirmed that the DCM extract was stable over the whole range of concentrations, and a DCM fraction was used to confirm the improved lipid metabolism effect. Lipid excretion was measured to confirm the change of lipid metabolism. 3T3-L1 cells induced by adipocytes were treated with DCM extract and stained with oil-red O to evaluate lipid accumulation. As a result, it was confirmed that the lipid efflux was significantly improved. In order to confirm the mechanism of lipid efflux, the mRNA expressions of ABCA1 and ABCG1, which are lipid transport proteins, were confirmed by real-time PCR. Therefore, the present study confirmed that the DCM extract from Orostachys japonicus has the effect of improving the lipid metabolism on 3T3-L1 adipocytes. In addition, the results of this study will be used as the basis for the development of functional foods using Orostachys japonicus and also for conducting research on the detailed mechanisms.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.6
• /
• pp.129-140
• /
• 2003

Recently viruses and various hacking tools that threat hosts on a network becomes more intelligent and cleverer, and so the various security mechanisms against them have ken developed during last decades. To detect these network attacks, many NIPSs(Network-based Intrusion Prevention Systems) that are more functional than traditional NIDSs are developed by several companies and organizations. But, many previous NIPSS are hewn to have some weakness in protecting important hosts from network attacks because of its incorrectness and post-management aspects. The aspect of incorrectness means that many NIPSs incorrectly discriminate between normal and attack network traffic in real time. The aspect of post-management means that they generally respond to attacks after the intrusions are already performed to a large extent. Therefore, to detect network attacks in realtime and to increase the capability of analyzing packets, faster and more active responding capabilities are required for NIPS frameworks. In this paper, we propose a framework for real-time intrusion prevention. This framework consists of packet filtering component that works on netfilter in Linux kernel and traffic control component that have a capability of step-by-step control over abnormal network traffic with the CBQ mechanism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.27-30
• /
• 2022

The plasma process, which has many advantages in terms of efficiency and environment compared to conventional process methods, is widely used in semiconductor manufacturing. Plasma Sheath is a dark region observed between the plasma bulk and the chamber wall surrounding it or the electrode. The Plasma Sheath Monitoring Sensor (PSMS) measures the difference in voltage between the plasma and the electrode and the RF power applied to the electrode in real time. The PSMS data, therefore, are expected to have a high correlation with the state of plasma in the plasma chamber. In this study, a model for predicting the state of nitrogen ions in the plasma chamber is training by a deep learning machine learning techniques using PSMS data. For the data used in the study, PSMS data measured in an experiment with different power and pressure settings were used as training data, and the ratio, flux, and density of nitrogen ions measured in plasma bulk and Si substrate were used as labels. The results of this study are expected to be the basis of artificial intelligence technology for the optimization of plasma processes and real-time precise control in the future.

• Cartoon and Animation Studies
• /
• s.29
• /
• pp.103-128
• /
• 2012

Study about existence of illusion which human beings feel from imitated image based reality have been continuing by copy theory and conventionalism for a long time. Traditional copy theory which had controlled representation theory from plato have explained illusion by similarity of image and representation objects. According to copy theory, image is natural sign unlike language but the late in the 20th century, conventionalism from N, Goodman insists they are not any special similarity between image and representation objects. They insist image and conventional sign just as language. These opposit theory rearranged conventionalism by the entrance on the cognitive science. The copy theory couldn't explain the problem of representational gap between reality and duplication, but photo media makes new paradigm about theory of the illusion. The problem of representational gap was disappeared by CGI images on the base of digital media. We are exposed exquisite duplication for a example, movie, advertisement, printings. Sometimes duplications are more real than the original works. Digital is a non-material object by 0 and 1. Specially real lighting skill and mechanism are copied perfectly by photon mapping skills and the duplications are produced more real than the original works. By disappearance of representational gap, we need new theory model for explaining of digital illusion and copy theory can be the key.

• KEPCO Journal on Electric Power and Energy
• /
• v.6 no.3
• /
• pp.305-313
• /
• 2020

The use of cable tunnels for electric power transmission as well as their construction in difficult conditions such as in subsea terrains and large overburden areas has increased. So, in order to efficiently operate the small diameter shield TBM (Tunnel Boring Machine), the estimation of advance rate and development of a design model is necessary. However, due to limited scope of survey and face mapping, it is very difficult to match the rock mass characteristics and TBM operational data in order to achieve their mutual relationships and to develop an advance rate model. Also, the working mechanism of previously utilized linear cutting machine is slightly different than the real excavation mechanism owing to the penetration of a number of disc cutters taking place at the same time in the rock mass in conjunction with rotation of the cutterhead. So, in order to suggest the advance rate and machine design models for small diameter TBMs, an EPB (Earth Pressure Balance) shield TBM having 3.54 m diameter cutterhead was manufactured and 19 cases of full-scale tunneling tests were performed each in 87.5 ㎥ volume of artificial rock mass. The relationships between advance rate and machine data were effectively analyzed by performing the tests in homogeneous rock mass with 70 MPa uniaxial compressive strength according to the TBM operational parameters such as thrust force and RPM of cutterhead. The utilization of the recorded penetration depth and torque values in the development of models is more accurate and realistic since they were derived through real excavation mechanism. The relationships between normal force on single disc cutter and penetration depth as well as between normal force and rolling force were suggested in this study. The prediction of advance rate and design of TBM can be performed in rock mass having 70 MPa strength using these relationships. An effort was made to improve the application of the developed model by applying the FPI (Field Penetration Index) concept which can overcome the limitation of 100% RQD (Rock Quality Designation) in artificial rock mass.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.1
• /
• pp.63-75
• /
• 2009

The aim of this study was to elucidate the antimelanogenic effect of Dokhwalkisaeng-tang(Duohujisheng-tang) in B16F10 melanoma cells. Dokhwalkisaeng-tang(DKT) was used to develop the effective prescription of inhibition of melanin production. We determined inhibitory effects of DKT on melanin-release, melanin production, and tyrosinase activity in B16F10 melanoma cells. And to explicate the action-mechanism of DKT, melanin-related gene expressions were determined using RT-PCR and real time RT PCR technique in B16F10 melanoma cells. DKT inhibited melanin-release, melanin production in B16F10 melanoma cells considerably. DKT inhibited tyrosinase activity in vitro and in B16F10 melanoma cells. DKT inhibited the expression of tyrosinase, TRP-1, TRP-2 in B16F10 melanoma cells. DKT inhibited the expression of PKA, PKC, MMP-2 and MITF in B16F10 melanoma cells. On the other hand, DKT increased the expression of ERK-1, ERK-2, AKT-1 in B16F10 melanoma cells. From these results, we propose that DKT may have effect on the antimelanogenesis.

• The Journal of Pediatrics of Korean Medicine
• /
• v.26 no.3
• /
• pp.30-45
• /
• 2012

Objectives The suppressive effect of CSBHT has been mysterious. Thus, the present study is designed to investigate the suppressive effect and its mechanism. Methods To investigate the anti-allergy effect from ChungShimBoHyeolTang(CSBHT), RBL-2H3 cell was used and examined by Real-Time PCR, and IL-4 and IL-13 from RBL-2H3 was examined by ELIS. In addition, GATA-1, GATA-2, NFAT-1, NFAT-2, c-Fos, c-Jun, NF-${\kappa}B$ p65 transcription factors of RBL-2H3 mast cell were examined by Western Blotting. Also, OVA/alum-sensitized mice were orally administrated CSBHT and serum OVA-specific IgE production, IL-4, and IL-13 production in splenocytes supernatant were examined. Results As a result of treating with CSBHT extract, RBL-2H3 mast cells significantly suppressed the IL-4 and IL-13 mRNA expression and IL-4 and IL-13 production. Western blot analysis of transcription factors involving IL-4 and IL-13 expression also revealed a prominent decreases of mast cell's specific transcription factors including GATA-1, GATA-2, NFAT-1, NFAT-2, c-Fos, and NF-${\kappa}B$ p65. Also, examining the mice, administration of CSBHT suppressed the amount of OVA-specific IgE in OVA/alum-sensitized mice and IL-4 and IL-13 production in splenocytes supernatant. Conclusions The study suggested that the anti-allergic activities of CSBHT suppresses IL-4 and IL-13 production from the Th2 cytokines by suppressing transcription factors as GATA-1, GATA-2, NFAT-1, NFAT-2, c-Fos and NF-${\kappa}B$ p65 in mast cells.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.7
• /
• pp.891-897
• /
• 2013

In this study, the compressive deformation behaviors of aluminum alloy under high strain rates were investigated by means of a SHPB test. An acoustic emission (AE) technique was also employed to monitor the signals detected from the deformation during the entire impact by using an AE sensor connected to the specimen with a waveguide in real time. AE signals were analyzed in terms of AE amplitude, AE energy and peak frequency. The impacted specimen surface and side area were observed after the test to identify the particular features in the AE signal corresponding to the specific types of damage mechanisms. As the strain increased, the AE amplitude and AE energy increased whereas the AE peak frequency decreased. It was elucidated that each AE signal was closely associated with the specific damage mechanism in the material.