• 제목/요약/키워드: Matrix effect

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식물추출물의 Matrix Metalloproteinase-2에 대한 저해활성 (Inhibitory Activity of Plant Extracts on Matrix Metalloproteinase-2)

  • 이상명;전효곤;이호재;이충환;김진희;고영희
    • 생약학회지
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    • 제33권2호통권129호
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    • pp.137-143
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    • 2002
  • The inhibitory effects of methanol extracts of 165 medicinal herbs on matrix metalloproteinase-2 (MMP-2) activity were investigated. Amongst the herbal extracts, Youngia denticulate, Platycarya strobilacea, Sedum kamtschaticum, Euscaphis japonica, and Comus controversa showed a significant inhibitory effect with above 80% at $1\;{\mu}g/ml$. Above mentioned five kind extracts, which exclude polyphenols and/or tannin by techniques for their removal, showed a mild inhibitory effect on MMP-2 activity except for Y. denticulate at the same concentration.

Dynamic analysis of trusses including the effect of local modes

  • Levy, Eldad;Eisenberger, Moshe
    • Structural Engineering and Mechanics
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    • 제7권1호
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    • pp.81-94
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    • 1999
  • The dynamic analysis of trusses using the finite element method tends to overlook the effect of local member dynamic behavior on the overall response of the complete structure. This is due to the fact that the lateral inertias of the members are omitted from the global inertia terms in the structure mass matrix. In this paper a condensed dynamic stiffness matrix is formulated and used to calculate the exact dynamic properties of trusses without the need to increase the model size. In the examples the limitations of current solutions are presented together with the exact results obtained from the proposed method.

Effect of Matrix Viscosity on Clay Dispersion in Preparation of Polymer/Organoclay Nanocomposites

  • Ko, Moon-Bae;Jho, Jae-Young;Jo, Won-Ho;Lee, Moo-Sung
    • Fibers and Polymers
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    • 제3권3호
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    • pp.103-108
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    • 2002
  • The viscosity effect of matrix polymer on melt exfoliation behavior of an organoclay in poly($\varepsilon$-caprolactone) (PCL) was investigated. The viscosity of matrix polymer was controlled by changing the molecular weight of poly($\varepsilon$-eaprolactone), the processing temperature, and the rotor speed of a mini-molder. Applied shear stress facilitates the diffusion of polymer chains into the gallery of silicate layers by breaking silicate agglomerates down into smaller primary particles. When the viscosity of PCL is lower, silicate agglomerates are not perfectly broken into smaller primary particles. At higher viscosity, all of silicate agglomerates are broken down into primary particles, and finally into smaller nano-scale building blocks. It was also found that the degree of exfoliation of silicate layers is dependent upon not only the viscosity of matrix but thermodynamic variables.

Fuzzy Service FMEA 및 HOQ 행렬 대수를 이용한 서비스 시스템 설계 (Service System Design Using Fuzzy Service FMEA and HOQ Matrix Algebra)

  • 김준홍
    • 산업경영시스템학회지
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    • 제35권3호
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    • pp.155-162
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    • 2012
  • This study proposes an integrated approach that uses both a fuzzy service FMEA (failure mode and effect analysis) and HOQ (house of quality) matrix algebra in designing and improving a service system. The fuzzy service FMEA methodology applies the customer satisfaction to the fuzzy RPN model. We fuzzify only the service satisfaction that consist in two failure factors, intangible service and tangible service, to more effectively assess the customer satisfactions on service encounters. Proposed fuzzy service satisfactions with triangle membership function are defuzzified by using the Fuzzy Inference System, and these are eventually identified the ranks on the potential fail points. HOQ matrices are constructed from cause-effect relationships. It is possible for these relationship matrix to find a linear approximation solution on the engineering attributes. Thus, in order to demonstrate how the proposed methods work, practical sample of the A/S part in S Electronic Co. provides for the ranking of the engineering attributes which has been successfully implemented.

Inhibitory effect of 2-amino-3-ethoxycarbonyl-1-methyl pyrolo (3,2-b) naphtho-4,9-dione on tumor cell invasion in human fibrosarcoma cells by downregulating matrix metalloproteinase-2 and 9

  • Park, Hyen-Joo;Hwang, Hye-Jin;Lee, Hyun-Jung;Suh, Myung-Eun;Lee, Sang-Kook
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.243.1-243.1
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    • 2002
  • Matrix metalloproteinases (MMPs) play an important role in tumor invasion and metastasis by matrix degradation. To analyze the effect of 2-amino-3-ethoxycarbonyl-1-methyl pyrolo (3,2-b) naphtho-4,9-dione (compound 1) on the invasion or metastasis of cancer cells the expression of matrix metalloproteases (MMPs) was investigated in human fibrosarcoma HT 1080 cells by AT -PCR or gelatin zymographic methods. (omitted)

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Matrix Metalloproteinase: Inhibitory Effect of Marine Substances on MMP-2 and MMP-9

  • Nguyen, Van-Tinh;Qian, Zhong-Ji;Jung, Won-Kyo
    • 통합자연과학논문집
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    • 제4권4호
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    • pp.255-265
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    • 2011
  • Marine ecosystems are often characterized by a high biological diversity, and it corresponds to a high chemical diversity. Up to present, more than 20,000 new bioactive substances have been isolated from marine organisms, where considerable numbers of these naturally occurring derivatives are developed as potential candidates for pharmaceutical application. In this process, screening of natural products from marine organisms that could potentially inhibit the expression of metalloproteinases has gained a huge popularity. Cancer is considered as one of the deadliest diseases in the medical field. Matrix metalloproteinase (MMPs) can degrade extracellular matrix (ECM) components and play important roles in a variety of biological and pathological processes. Matrix metalloproteinase inhibitors (MMPIs) have been identified as potential therapeutic candidates for metastasis, arthritis, chronic inflammation and wrinkle formation.

금속복합재료와 고분자복합재료의 마모 특성 비교 (Comparison of Wear Property Between Metal and Polymer Matrix Composites)

  • 김재동
    • 수산해양교육연구
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    • 제28권6호
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    • pp.1875-1881
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    • 2016
  • The wear behavior for the two types of composites, those are epoxy matrix composites filled with silica particles and aluminium matrix composites filled with SiC particles, were compared to investigate the wear mechanism for these composites. Especially, the effect of the volume fraction for the epoxy matrix composites and the particle size for the aluminium matrix composites according to the apply load and sliding velocity were investigated. Wear tests of the pin-on-disc mode were carried out and followed by scanning electron microscope observations for the worn surface. The addition of the fillers in the composites were improved the wear resistance significantly and changed the wear mechanism for the both composites. These results were identified by the observation of the worn surface after testing.

Effect of Ethanolamine Salts and Enhancers on the Percutaneous Absorption of Meloxicam from a Pressure Sensitive Adhesive Matrix

  • Ki, Han-Moe;Cheong, Hyun-Ah;Choi, Hoo-Kyun
    • Journal of Pharmaceutical Investigation
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    • 제37권3호
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    • pp.173-177
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    • 2007
  • The purpose of this study was to investigate the effect of salt formation on the percutaneous absorption of meloxicam through hairless mouse skin from a pressure sensitive adhesive (PSA) matrix. In addition, the influences of enhancers on the permeation of meloxicam or meloxicam-ethanolamine (MX-EA) salts across the hairless mouse skin were evaluated using a flow-through diffusion cell system. The salt formation of meloxicam resulted in lower permeation rate than the parent drug. $Span^{(R)}$ 80 provided the highest enhancing effect for meloxicam and meloxicam monoethanolamine salt. The maximum amount of the drug that can be loaded without retarding permeation rate was different depending on the compound. No relationship was found between the fluxes of meloxicam or MX-EA salts from saturated solutions and those from PSA matrices containing the same enhancer.

Yield enhancement of matrix precursor in short carbon fiber reinforced randomly oriented carbon/carbon composite

  • Raunija, Thakur Sudesh Kumar;Sharma, Sharad Chandra;Verma, Anil
    • Carbon letters
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    • 제19권
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    • pp.57-65
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    • 2016
  • Isroaniso matrix precursor synthesized from commercially available petroleum pitch was stabilized in air. The influence of oxygen mass gain during stabilization on the yield of matrix precursor was studied. Additionally, the influence of pressure on the yield of the stabilized matrix precursor in a real system was studied. The fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA), yield, yield rate, and yield impact were used to check the effect of stabilization and pressure on the yield of the matrix precursor and the end properties of the composite thereafter. The results showed that the yield increased with stabilization duration up to 20 h whereas it decreased for stabilization duration beyond 20 h. Further results showed that the stabilized matrix precursor for a duration of 5 h could withstand almost two-fold greater hot-pressing pressure without resulting in exudation as compared to that of a 1 h stabilized matrix precursor. The enhanced hot-pressing pressure significantly improved the yield of the matrix precursor. As a consequence, the densification and mechanical properties were increased significantly. Further, the matrix precursor stabilized for a duration of 20 h or more failed to provide proper and uniform binding of the reinforcement.