• Biomedical Science Letters
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• v.20 no.3
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• pp.103-110
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• 2014

Matrix metalloproteinases (MMPs), also called matrixins, function in the extracellular environment of cells and degrade both matrix and non-matrix proteins. They are multidomain proteins and their activities are regulated by tissue inhibitor of metalloproteinases (TIMPs). The uncontrolled regulation of MMPs is involved in various pathologic processes, such as tumor invasion, migration, host immune escape, extravasation, angiogenesis, and tumor growth. Especially, matrix metalloproteinase-9 (MMP-9) is one of the metastasis-accelerating genes involved in metastasis of various types of human cancers. Here, we review the member of MMP family and discusses their domain structure and function, enzyme activation, the mechanism of inhibition by TIMPs. In particular, we focus the role of MMP-9 in relation to cancer metastasis.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3119-3121
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• 2012

• Journal of Nutrition and Health
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• v.39 no.8
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• pp.756-761
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• 2006

Curcumin has been known for its anti-proliferative and apoptotic effects on several cancer cells. We examined the inhibitory effects of curcumin on cancer cell adhesion, motility, invasion and matrix metalloproteinase-9 (MMP-9) activity in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were cultured with 0, 5, 10 or $20{\mu}M$ of curcumin. Curcumin significantly inhibited the adhesion of cancer cells to the fibronectin at $20{\mu}M$ and suppressed the motility and invasion of cancer cells at all concentrations. Also, the MMP-9 activity was inhibited by curcumin, but MMP-9 protein amounts were not affected. Our data indicate that curcumin inhibits motility, invasion and MMP-9 activity of MDA-MB-231 cells. Therefore, curcumin may contribute to the potential beneficial food component to prevent the cancer metastasis in human breast cancer.

• Journal of Institute of Convergence Technology
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• v.9 no.1
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• pp.1-6
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• 2019

Matrix multiplication is a fundamental mathematical operation that has numerous applications across most scientific fields. In this paper, we presents a parallel GPU computation algorithm for dense matrix-matrix multiplication using OpenGL compute shader, which can play a very important role as a fundamental building block for many high-performance computing applications. Experimental results on NVIDIA Quad 4000 show that the proposed algorithm runs about 208 times faster than previous CPU algorithm and achieves performance of 75 GFLOPS in single precision for dense matrices with matrix size 4,096. Such performance proves that our algorithm is practical for real applications.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.82-89
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• 2006

Background: Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix, which is an important step in tumor invasion and metastasis. A positive correlation between the expression of MMP-9 and aggressive behavior of renal cell carcinomas (RCCs) has been reported. MMP-9 expression in RCCs and adjacent normal kidney tissues were examined in this study. Materials and Methods: Twenty-five patients pathologically diagnosed as clear cell RCCs, from specimens obtained at radical nephrectomy, between May 2003 and December 2004 were enrolled in this study. MMP-9 activity was estimated using gelatin zymography, and quantified using a laser densitometer. The results were compared with clinicopathological characteristics. Results: The expression of MMP-9 was significantly elevated in the RCC compared with non-tumor kidney specimens (p<0.01). The levels of MMP-9 expression in the RCC patients with large tumors (>4 cm) or vascular invasion were significantly higher than in those without these clinical manifestations (p<0.01). There were also significant differences in the expression of MMP-9 among T stages (p<0.01). The tissue MMP-9 level was the highest in nuclear grade 4, but there was no statistical significance between the histological grades (p=0.17). Conclusions: These results suggest that enhanced MMP-9 expression contributes to carcinogenesis and tumor progression in the later stages of RCC.

• Biomedical Science Letters
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• v.9 no.3
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• pp.123-131
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• 2003

Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study hypothesized that a vascular infection with cytomegalovirus (CMV) may induce a chronic inflammatory reaction and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases-9 (MMP-9). To confirm the hypothesis, the immunohistochemical stains for CMV late antigen, COX-2, MMP-9, macrophage, and T-lymphocyte were performed on CMV-infected atherosclerotic lesions. The immunoreactivity for COX-2 and MMP-9 was evident in all cases of atherosclerosis along with plaques, mainly in macrophages/foamy cells, intimal and medial smooth muscle cells, and endothelial cells of the intima. Within the intima, the increased immunoreactivity for COX-2 and MMP-9 was colocalized to the area stained with CMV late antigen. Sections from control specimens showed no immunoreactivity for CMV late antigen, COX-2 and MMP-9. These data seem to support the hypothesis that CMV may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis.

• Journal of Biosystems Engineering
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• v.30 no.4 s.111
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• pp.202-209
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• 2005

The output of Stirling engine is influenced by the regenerator effectiveness. The regenerator effectiveness is influenced by heat transfer and flow friction loss of the regenerator matrix. In this paper, in order to provide a basic data for the design of regenerator matrix, characteristics of heat transfer and flow friction loss were investigated by a packed method of matrix in the oscillating flow as the same condition of operation in a Stirling engine. As matrices, 6 kinds of steel wires, 4 kinds of combined steel wires, 8 kinds of combined steel wires with screen meshes were used. The results are summarized as follows; Among 6 kinds of steel wires $({\phi}0.7\;mm,\;{\phi}0.9\;mm,\;{\phi}1.2\;mm,\;{\phi}\;1.6\;mm,\;{\phi}2.0\;mm,\;{\phi}2.7\;mm),$ the two steel wires $({\phi}0.7\;mm,\;{\phi}0.9\;mm)$ showed the highest in effectiveness. Among 4 kinds of combined steel wires $({\phi}l.6-{\phi}l.2\;mm,\;{\phi}1.2-{\phi}l.6\;mm,\;{\phi}0.9-{\phi}l.2\;mm,\;{\phi}l.2-{\phi}0.9\;mm),\;the\;{\phi}1.2-{\phi}0.9\;mm$ showed the highest in effectiveness. Among 8 kinds of combined steel wires with screen meshes $(150-{\phi}0.9\;mm,\;150-{\phi}l.2\;mm,\;{\phi}0.9\;mm-150,\;{\phi}1.2\;mm-150,\;150-{\phi}0.9\;mm-150,\;150-{\phi}1.2\;mm-150,\;150-{\phi}l.6\;mm-150,\;150-{\phi}2.0\;mm-150),\;the\;{\phi}l.2\;mm-150$ showed the highest in effectiveness.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.107-113
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• 2016

In this paper, we suggest a design method of a wide-band Butler matrix working at 5.9 GHz for V2X communication antennas. Since V2X communication needs beam-forming and beam-steering antennas to make transportation systems, mobile comm platforms, saturated frequency-resources, and signal TX-and-RX smart, multi-functional, resolved, and efficient utmost, respectively, the proper Butler matrix and its radiating elements as a low-profile geometry are realized. The constitutive components of the basic Butler matrix of a narrow band are designed first. And then, it is extended to a wide-band version to make its frequency-shift less affected by the event of the antenna system being mounted on a car body. The beam-forming and beam-steering performance is presented as the common feature tagged along with the different bandwidths of the frequency responses as the comparison between the narrow- and wide-band cases.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1583-1589
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• 2001

Metal matrix composites with whisker reinforcements have significant potentials for demanding mechanical applications including defense, aerospace, and automotive industries. Especially metal matrix composites, which are reinforced with aluminum borate whisker, have been used leer the part of piston head in automobile because of good specific strength and wear resistance. In this study, AC4CH-based metal matrix composites with $Al_{18}$B$_{4}$ $O_{33}$ reinforcement have been produced using squeeze casting method, after T6 heat treatment, we evaluated fatigue life property of matrix and MMC composite and investigated fracture mechanism.m.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7393-7400
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• 2015

Matrix metalloproteinase (MMP) 9, a key member of multifunctional family of zinc dependent endopeptidases has been found to be upregulated during inflammation and in some cancers. MMPs cleave extracellular matrix (ECM) proteins and play critical roles in cellular apoptosis, angiogenesis, tumor growth and metastasis. Several genetic polymorphisms have been identified that show allele specific effects on MMP9 regulation and are associated with gastric cancer, the fourth most common malignancy in the world. Besides Helicobacter pylori infection, genetic predisposition is another documented risk factor for gastric carcinoma. The single nucleotide polymorphism (SNP) at position -1562C/T of MMP9 results in the modulation for binding of transcription factors to the MMP9 gene promoter and thereby causes differences in protein expression and enzymatic activity. MMP9 transcriptional regulation during gastric cancer development remains poorly known although several studies have demonstrated associations between MMP9 -1562 C/T polymorphism with different diseases. Knowledge on mechanisms of MMP9 upregulation during gastric cancer may provide new paradigm in diagnostics and therapeutics.