• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.398-404
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• 2013

During a screening program to search the anticolitic herbal medicines, 80% ethanol extract of the rhizome of Anemarrhena asphodeloides (AA) was found to potently inhibit the expression of proinflammatory cytokines TNF-${\alpha}$ and IL-1${\beta}$, as well as the activation of NF-${\kappa}B$ in LPS-stimulated colonic macrophages, followed by that of the rhizome of C. chinensis (CC). AA also potently inhibited TNBS-induced colitic markers, shortening of the colon and increase of macroscopic score, myeloperoxidase activity, TNF-${\alpha}$, IL-1${\beta}$, and IL-6, in mice. The synergistic effect of CC against the anticolitic effect of AA was investigated. CC synergistically inhibited the anticolitic effect of AA. AC-mix (AA+CC, 1:1) potently inhibited them. AC-mix also inhibited the activation of NF-${\kappa}B$, as well as the expression of TNF-${\alpha}$, IL-1${\beta}$, IL-6, iNOS and COX-2. The effects of AC-mix against oxazolone-induced colitis were investigated in mice. AC-mix also potently inhibited oxazolone-induced inflammatory markers, colon shortening, macroscopic score, myeloperoxidase activity, NF-${\kappa}B$ activation and proinflammatory cytokines. Overall, the anti-colitic effect of AC-mix was superior to that of mesalazine. Based on these findings, AC-mix may improve colitis by inhibiting NF-${\kappa}B$ activation.

• The Journal of Internal Korean Medicine
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• v.42 no.1
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• pp.11-24
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• 2021

Objective: Chronic reflux esophagitis (CRE), characterized by esophageal mucosa ulcer, is caused by continuous backflow of gastric acid and consequent inflammation due to unstable gastroesophageal sphincter. The aim of the present study was to clarify the effect of an Arecae Semen and Coptidis Rhizoma mixture (AC-mix) on CRE. Methods: CRE was surgically induced in SD rats with three experimental groups used: normal; CRE control; and CRE treatment (200 mg/kg AC-mix). Blood and esophageal tissue were collected after two weeks of drug administration. The anti-oxidant activity of the AC-mix was measured by total polyphenol and total flavonoid contents as well as by radical scavenging activity with protein levels evaluated using western blotting. Results: CRE damage to the esophageal mucosa was significantly reduced in the AC-mix group as compared with the controls, and administration of the AC-mix was seen to inhibit NF-κBp65 activity. Consequently, the inactivation of NF-κBp65 significantly inhibited inflammatory mediators such as COX-2 and iNOS. Moreover, the anti-oxidant enzyme HO-1 significantly increased through activation of the Nrf2-Keap1 pathway. Matrix metalloproteinase-2 (MMP-2), which can break down collagen from the basement membrane and extracellular matrix, was decreased following AC-mix treatment, and elevated levels of MMP-2 were regulated by its tissue inhibitor. Conclusions: These results show that AC-mix can alleviate esophageal mucosa ulcer though inhibition of the NF-κBp65 inflammatory pathway and enhancement of the anti-oxidant Nrf2-Keap1 pathway.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.163-166
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• 2006

This paper presents numerical results of fluid flows and mixing in a microfluidic device for AC electroosmotic flow (AC-EOF) with coplanar electrodes on top and bottom walls. Differently from previous EOF a channel which attached a couple of coplanar electrodes can be utilized to mix a target liquid with a reagent. In this study we propose a method of controlling fluid flows and mixing enhancement. To obtain the flow and mixing characteristics, numerical computations are performed by using a commercial code, CFX10. It was found that the flow near the coplanar electrodes is of 3-D complex flows and vortices between the other electrodes, and as a consequence the AC-electroosmotic flow on the electrodes plays an important role in mixing the liquid.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.350-355
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• 1998

Preplaced aggregate concrete in the building fields has recently been used in the partial repair works for damaged reinforced concrete structures, and polymer-modified mortars have been employed as grouting mortars for the preplaced aggregate concrete. The objective of this study is to clear the properties of polymer-modified grouting mortars. Polymer-modified mortars using a polystyrene acrylic(St/Ac) emulsion as grouting mortars for preplaced aggregate concrete are prepared with various mix proportions, and tested for flexural and compressive strengths, adhesion in tension. The flexural strength of emulsion-modified grouting mortars does not give much variation with increasing fly ash replacement for cement and sand-binder ratio. With increasing polymer-binder ratio, the flexural strength and adhesion in tension of St/Ac emulsion-modified grouting mortars increases, become nearly constant or reaches a maximum at a polymer-binder ratio of 5%. From the test results, St/Ac emulsion-modified grouting mortar with a polymer-binder ratio of 5%, a fly ash replacement of 10% for cement and sand-binder ratio of 1.0 is recommended as a grouting mortar for preplaced aggregate concrete.

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.65-73
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• 2004

Marshall stability and flow don't reflect mechanical property of asphalt mixtures and have little correlation with rutting-related performance. There is often rutting occurred on the asphalt pavement which was constructed using a mixture passing the specification for stability and flow. This study dealt with comparison of volumetric properties of mixtures from Marshall mix design and from Superpave mix design. This study used one binder, three aggregates and two gradations. The mixtures were manufactured by each mix design method. Result showed that OAC, VMA and VFA by Marshall mix design were higher than those by Superpave mix design. This is because Mashall mixture has the gradation prone to rutting and it should be further investigated whether or not the high OAC is direct cause of rutting in asphalt pavement.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.356-361
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• 1998

Permeable polymer cement concrete in this study is one of the invironment conscious concretes that can be applied at roads, side walks, parking lots, interlocking block and river embankment, etc. In this study, permeable polymer cement concretes using polymer dispersion(St/Ac) with water-cement ratios of 25, 30, 35 and 40%, polymer-cement ratios of 0, 5, 10, 15 and 20%, and a ratio of cement to aggregate (by weight), 1 : 3.5(about 415kg/㎥), 1 : 4.0(about 375 kg/㎥), and 1 : 4.5(about 345kg/㎥) are prepared, and tested for compressive, flexural and tensile strength, and permeability. From the test results, increase in the strengths of permeable polymer cement concrete are clearly observed with increasing polymer-cement ratio, we can obtain the maximum strengths at water-cement ratio of 35%. The optimum permeable polymer cement concrete according to application and location of work can be selected in various mix proportions.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1247-1252
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• 2002

Mass-analyzed threshold ionization (MATI) technique is optimized to generate substantial amount of state-selected molecular ions sufficient for dynamics study. The main strategy is to stabilize intermediate (n = 100- 200) Rydberg states by l,m-mix ing induced by AC field. Electrical jitter inherent in high voltage switching is utilized for this purpose. A related technique to locate the MATI onset is also described.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.11a
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• pp.67-76
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• 2002

Self-leveling material(SLM) is one of the floor finishing materials which make flat surface like as water level by itself in a short time. So it is possible to increase construction speed and enhance economical efficiency. In this study, author intended to develop SLM for the industrial warehouse and factory loading heavy weight machinery and vehicles. The demanded properties for this type of SLM are above 20mm of flow value and above 300kgf/cm2 of 28-days compressive strength. To possess demended strength and fluidity, SLM have to be composed of many types of binders and chemical additives. So it is difficult to decide suitable mixing proportion of composition materials. In this study, author investigated the weight percentage effect of main composition materials for high-strength self-leveling material, by experimental design such as tables of orthogonal arrays and simplex design, and by statistical analysis such as analysis of variance and analysis of response surface. Variables of experiments were ordinary portland cement(OPC), alumina cement(AC), anhydrous gypsum(AG), lime stone(LS) and sand, and properties of tests were fluidity of fresh state and strength of hardened state. Results of this study are showed that suitable mix proportions of binders for the high strength self-leveling materials are two groups. One is 78~85.5% OPC, 7.5~9.5% AC, 9~12.5% AG and the other is 72.5~78% OPC, 9~12.5% AC, 13~l5% AG.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.21-25
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• 2009

The results of a recent case study for material characterizations and structural evaluation to design asphalt overlay thickness of William P Hobby airport in Houston, Texas are presented herein. The existing runway 12R-30L of Hobby airport consisted of thick asphalt overlay over Portland Cement Concrete (PCC) and the localized surface shoving as evident in the closure of surface groove has been observed recently. Using the field cored asphalt concrete mixtures, measurements of percent air voids, asphalt content and aggregate gradation were conducted to find out the causations of surface shoving and groove closure. The FAA layered elastic program, LEDFAA was utilized to evaluate pavement structural conditions for new asphalt overlay. Two different composition assumptions for existing pavement were made to evaluate the pavement as followings: 1) APC, Asphalt Concrete Overlay over PCC pavement and 2) AC, Asphalt Concrete pavement. Based on laboratory testing results, a ratio of percent passing #200 to asphalt content ranged 1.1 to 2.2, which is considered a high ratio and a tendency of tender mix design was observed. Thus, the localized surface shoving and groove closure of the runway 12R-30L could be attributed to the use of excessive fine contents and tender mix design. Based on the structural evaluation results, it was ascertained that the analysis assuming the pavement structure as AC pavement gives more realistic structural life when the asphalt overlay is thicker enough compared to PCC layer because the existing PCC pavement under asphalt overlay acts more like a high quality base material.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.5
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• pp.457-467
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• 2005

This paper deals with the new frequency controller of the HVDC scheme linking Haenam to Cheju Island. The primary aim of the study is to develop and evaluate a new frequency controller after the removing of the present synchronous compensators. The simulation methods are the mix of PSCAD/EMTDC and PSS/E, the main system studies are done for the transient state analysis using PSCAD/EMTDC. The study cases are completed involving 3 phase, single phase trip and load tripping events and study plots presented. In conclusion, the new frequency measurement from the AC network gives effective frequency control and dynamic performance.