• Tuberculosis and Respiratory Diseases
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• v.68 no.3
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• pp.168-174
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• 2010

Background: Sepsis still has a high mortality rate despite adequate supportive care. Newer therapeutic modalities have been developed but they have generally ended in failure. Recently, insulin was reported to have an anti-inflammatory effect by inhibiting the $I{\kappa}B/NF-{\kappa}B$ pathway, and may have therapeutic potential in sepsis. However, the precise mechanism of the anti-inflammatory effect of insulin is unclear. This study examined the role of insulin in activating $I{\kappa}B/NF-{\kappa}B$ in macrophage. Methods: Raw 264.7 cells, a murine macrophage cell line, were used in this experiment. Western blotting using $I{\kappa}B$ Ab and phosphor-specific $I{\kappa}B$ Ab was performed to evaluate the degradation and phosphorylation of $I{\kappa}B$ cells. For the $I{\kappa}B$ Kinase (IKK) activity, an immune complex kinase assay was performed. The level of interleukin-6 (IL-6) was measured by ELISA to determine the level of proinflammatory cytokine. Results: $I{\kappa}B{\alpha}$ degradation began 30 min after lipopolysaccharide (LPS) treatment. However, an insulin pretreatment suppressed the $I{\kappa}B{\alpha}$ degradation caused by the LPS treatment. The phosphorylation of $I{\kappa}B{\alpha}$ and IKK activity was also inhibited by the insulin pretreatment. Finally, the insulin pretreatment showed a tendency to suppress the induction of IL-6 by LPS. Conclusion: Insulin might have an anti-inflammatory effect though partial inhibition of the $I{\kappa}B/NF{\kappa}B$ pathway in macrophage cell lines.

• The Journal of Internal Korean Medicine
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• v.31 no.4
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• pp.731-751
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• 2010

Objectives : The present study aimed to find out the effect of Sagunja-tang on the prevention and treatment of inflammatory bowel disease using mice with TNBS-induced inflammatory bowel disease. Methods : Mice with TNBS-induced inflammatory bowel disease were medicated with Sagunja-tang, and the weight changes, colon length, lipid peroxidation, and myeloperoxidase activity were observed. Levels of the inflammatory markers interleukin (IL)-$1{\beta}$ and cyclooxygenase-2 (COX-2), its transcription factor activation, phospho-NF-${\kappa}$B (pp65), in the colon by enzyme-linked immunosorbent assay and immunoblot analysis were also measured. Finally, the activation of fecal bacterial enzyme, ${\beta}$-glucuronidase and degradation activation of fecal glycosaminoglycan (GAG) and hyaluronic acid were observed. Results : We found that oral administration of Sagunja-tang inhibited TNBS-induced colon shortening and also inhibited myeloperoxidase activity in the colon of mice as well as IL-$1{\beta}$ and COX-2 expression. Sagunja-tang also inhibited TNBSinduced lipid peroxidation and pp65 activation in the colon of mice. In addition, Sagunja-tang inhibited ${\beta}$-glucuronidase activation and fecal hyaluronic acid degradation activation. Conclusions : It is supposed that Sagunja-tang has a potential therapeutic effect on inflammatory bowel disease through the inhibition of both NF-${\kappa}$B activation and lipid peroxidation, and the improvement of intestinal conditions.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.291-292
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• 2015

와전류 탐상 기법을 이용하여 배전선로의 내부 열화를 검출하는 시스템을 개발할 수 있는데, 본 연구에서는 이를 위하여 유한요소법을 통한 시뮬레이션으로 와전류 센서의 기초 모델링을 구상한 후 실제 와전류 센서를 제작하여 가속 열화에 의한 센서 특성을 조사하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.8
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• pp.1203-1210
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• 2004

It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.

• Structural Engineering and Mechanics
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• v.64 no.4
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• pp.427-436
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• 2017

Concrete technologists have used ultrasonic pulse velocity test for decades to evaluate the properties of concrete. However, the presented research work focuses on the use of ultrasonic pulse velocity test to study the degradation in steel-concrete bond subjected to increasing loading. A detailed experimental investigation was conducted by testing five identical beam specimens under increasing loading. The loading was increased from zero till failure in equal increments. From the experimentation, it was found that as the reinforced concrete beams were stressed from control unloaded condition till complete failure, the propagating ultrasonic wave velocity reduced. This reduction in wave velocity is attributed to the initiation, development, and propagation of internal cracking in the concrete surrounding the steel reinforcement. Using both direct and semidirect methods of testing, results of reduction in wave velocity with evidence of internal cracking at steel-concrete interface are presented. From the presented results and discussion, it can be concluded that the UPV test method can be successfully employed to identify zones of poor bonding along the length of reinforced concrete beam. The information gathered by such testing can be used by engineers for localizing repairs thereby leading to saving of time, labor and cost of repairs. Furthermore, the implementation strategy along with real-world challenges associated with the application of the proposed technique and area of future development have also been presented.

• Tuberculosis and Respiratory Diseases
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• v.71 no.3
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• pp.172-179
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• 2011

Background: Statins can regulate the production of pro-inflammatory cytokines and inhibit MMP production or activation in a variety of types of cells. This study evaluated whether statins would inhibit MMP release from human lung fibroblasts, which play a major role in remodeling processes. Methods: This study, using an in-vitro model (three-dimensional collagen gel contraction system), evaluated the effect of cytokines (tumor necrosis factor-${\alpha}$, TNF-a and interleukin-$1{\beta}$, IL-1b) on the MMP release and MMP activation from human lung fibroblasts. Collagen degradation induced by cytokines and neutrophil elastase (NE) was evaluated by quantifying hydroxyproline. Results: In three-dimensional collagen gel cultures (3D cultures) where cytokines (TNF-a and IL-1b) can induce the production of MMPs by fibroblasts, it was found that simvastatin inhibited MMP release. In 3D cultures, cytokines together with NE induced collagen degradation and can lead to activation of the MMP, which was inhibited by simvastatin. Conclusion: Simvastatin may play a role in regulating human lung fibroblast functions in repair and remodeling processes by inhibiting MMP release and the conversion from the latent to the active form of MMP.

• Polymer(Korea)
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• v.38 no.3
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• pp.351-357
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• 2014

In membrane covered stent, occlusion and fracture from membrane degradation by gastric acid sometimes occurred. Therefore, we investigated the physical properties of membrane covered stent according to its ingredient and concentration in gastric acid environment. Membrane covered stents consisted of silicone and polyurethane with 15%, 18%, 20% concentrations were used. After incubating stents in a condition of pH 1.2, we checked any changes at every 3 weeks for 18 weeks. The changes of membrane surface, radial expansion and recovery force of stent were investigated. Coating thickness increased proportionally to an increase in ingredient concentration. Surface was evenly coated with silicone compared to the case with polyurethane and its homogeneity was excellent in a high concentration. Degradation was much severe in the case of polyurethane. The radial force of silicone was higher than polyurethane, and the decrease of radial and recovery force was higher in the case of polyurethane. In conclusion, high concentration of silicone membrane was more stable than polyurethane in acid environment of in vitro study.

• Journal of Communications and Networks
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• v.1 no.2
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• pp.134-142
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• 1999

We have developed fully functional Video Server and Client applications which can transmit, receive, decompress and display compressed video over various networks. Our video trans-port allows dynamic rate control feedback, loss detection, and repair requests from Clients to the Server. Our experiments show how feedvack-before-degradation scheme for rate adaptation maintains good display frame-rate for video playback. We show how the playback degradation(reduction in display frame-rate) oc-curs and what happens if corrective measures are not taken to im-prove the situation. The degradation is attributed to the increased internal kernel buffering which consumes scarce CPU resources. We demontrate with our experimental results that ServerNet, with improved hardware delivery guarantees, can significantly reduce host CPU resource consumption while serving video streams. We present the maximum number of streams which can be served for each of ATM and ServerNet interconnects. The appropriate user-level packet size for the video server are also determined for each case.

• Journal of the Korean Ceramic Society
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• v.29 no.10
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• pp.806-814
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• 1992

The aim of this study was to investigate the change in compressive strength, freacture behavior and degradation of piezoelectric properties with compressive cyclic loading in Pb(Zr, Ti)O3 of tetragonal, morphotropic phase boundary and rhombohedral composition. The highest compressive strength was found in rhombohedral composition. After poling treatment the strength increased by 8.4% and 6.5% in tetragonal and morphotropic phase boundary compositions respectively while changed little in rhombohedral. The increase of compressive strength after poling treatment is believed to be due to the internal stress around grain boundary by domain alginment toward electric field direction in the microstructures having tetragonality and the occurrence of domain switching to the direction perpendicular to electrical field during fracture. Fracture mode relatively change from transgranular to intergranular was observed in the large grain sized tetragonal and morphotropic phase boundary compositions before and after poling but the transgranular fracture mode always remained in the rhombohedral composition. From the X-ray diffractometer analysis the domains parallel to the electric field direction is known to undergo rearrangement during the cyclic loading into random direction that is responsible for the degradation of piezoelectric property.

• ETRI Journal
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• v.16 no.1
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• pp.59-72
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• 1994

In this paper, a new N-way hybrid power combiner for improving the graceful degradation performance has been proposed. The proposed combiner has been configured with two dummy transmission lines per each section, where each dummy transmission line has a different characteristic impedance, of the standard combiner. Under this proposed configuration, a detailed theoretical analysis has been performed to show the general function of a power combiner. When any M amplifiers among N identical amplifiers are suffering the failure mode in a power combining circuit or system, the graceful degradation performance has been improved due to the separation of a transmission line and an internal resistor in every failed section from the proposed combiner by simultaneously operating two shorting devices. Simulation results for all the items which can be measured from all the items which can be measured from the proposed combiner with an eight-way configuration have been presented.