• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.685-695
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• 2004

The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four composite resins in an alkaline solution. The resistance to degradation was evaluated on the basis of mass loss(%), degradation depth(${\mu}m$), Si loss(ppm) and wear depth. The brands studied were Heliomolar flow, Filtek supreme, Point4, Tetric flow. The results were as follows: 1. The sequence of the mass loss was in descending order by Heliomolar flow, Filtek supreme, Point4, Tetric flow. There was significant differences among the materials except Heliomolar flow and Filtek supreme. 2. The sequence of the degree of degradation layer depth was in descending order by Filtek supreme, Heliomolar flow, Tetric flow, Point4. There were significant differences among the materials except Heliomolar flow and Tetric flow. 3. The sequence of Si loss was in descending order by Filtek supreme, Heliomolar flow, Point4, Tetric flow. There were significant differences among the materials except Point 4 and Tetric flow. 4. The sequence of maximum wear depth was in descending order by Heliomolar flow, Point4, Fillet supreme, Tetric flow and there was increasing wear depth on soaking in 0.1N NaOH solution. 5. When observed with SEM, destruction of bonding between matrix and filler was observed and when observed with CLSM, the depth of degradation layer of specimen surface was observed. There results indicate that wear and hydrolytic degradation could be considered to be evaluation factors of composite resins.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.2
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• pp.129-137
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• 2001

Matching pursuit algorithm was successfully demonstrated useful in low bit-rate video coding, However, one of the practical concerns related to applying the matching pursuit algorithm to application is its massive computation required for finding bases whose weighted sum best approximates the given input image. The main contribution of this paper is that we provide a new method that can drastically reduce the computational load without any degradation of image quality. Its main idea is based on reducing the number of inner product calculation required for finding best bases because the complexity of matching pursuit algorithm is due to the exhaustive local inner product calculation. As the first step, we compute a matrix which is the 1-D inner product of the given motion-compensated error input image with the 1-D vertical Gabor functions using the separable property of Gabor bases. In the second step, we calculate length of each vector in the matrix that corresponds to 1-D horizontal Gabor function, and compare the length with the current maximum absolute inner product value so far. According to the result of this comparison, one can decide whether or not to calculate the inner product. Since most of them do not need to calculate the inner product value, one can significantly reduce the computational load. Experimental results show that proposed method reduces about 70% of inner product calculation compared to the Neff's fast algorithm without any degradation of image quality.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.1
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• pp.49-56
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• 1996

In this paper, as a new grey scale method for simple matrix LCDs, the grey scale method using the new code scheme was proposed. The experiment and the characteristic estimation for the new grey scale method were performed by the simulation of the 16 and 32 grey patterns and the calculation of the driving voltages. As a result of the experiment and the characteristic estimation, the 16 grey mode using the 3 bits code scheme, (7, 5, 3) has the maximum driving voltage which is reduced by 19% and 9.6% each compared with the values in the conventional grey modes discussed in this paper. And the extent of improvement in the driving voltage characteristics is increased much as the number of grey levels increases. On the other hand, as a result of the grey image estimation through the grey pattern simulation, the 3 bits 16 grey mode degrades the characteristics of the grey image more or less compared with the conventional grey method but the extent of this characteristic degradation is much reduced with the increase in the number of grey levels such as 32 grey scale, etc. Consequently the grey scale method using the new code scheme proposed in this paper is confirmed as a method that it minimized the degradation of grey characteristics and improves the driving voltage characteristics effectively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.4
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• pp.439-450
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• 2003

Flat plate system has been adopted in many buildings constructed recently because of the advantage of reduced floor heights to meet the economical and architectural demands. Structural engineers commonly use the effective beam width model(EBWM) in practical engineering for the analysis of flat plate structures. However, in many cases, when it is difficult to use the EBWM, it is necessary to use a refined finite element model for an accurate analysis. But it would take significant amount of computational time and memory if the entire building structure was subdivided with finer meshes. An efficient analytical method is proposed in this study to obtain accurate results in significantly reduced computational time. The proposed method employs super elements developed using the matrix condensation technique and fictitious beams are used in the development of super elements to enforce the compatibility at the interfaces of super elements. The stiffness degradation of flat plate system considered in the EBWM was taken into account by reducing the elastic modulus of floor slabs in this study. Static and dynamic analyses of example structures were performed and the efficiency and accuracy of the proposed method were verified by comparing the results with those of the refined finite element model and the EBWM.

• Journal of Veterinary Science
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• v.24 no.6
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• pp.83.1-83.12
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• 2023

Background: Ellipticine (Ellip.) was recently reported to have beneficial effects on the differentiation of adipose-derived stem cells into mature chondrocyte-like cells. On the other hand, no practical results have been derived from the transplantation of bone marrow stem cells (BMSCs) in a rabbit osteoarthritis (OA) model. Objectives: This study examined whether autologous BMSCs incubated with ellipticine (Ellip.+BMSCs) could regenerate articular cartilage in rabbit OA, a model similar to degenerative arthritis in human beings. Methods: A portion of rabbit articular cartilage was surgically removed, and Ellip.+BMSCs were transplanted into the lesion area. After two and four weeks of treatment, the serum levels of proinflammatory cytokines, i.e., tumor necrosis factor α (TNF-α) and prostaglandin E2 (PGE2), were analyzed, while macroscopic and micro-computed tomography (CT) evaluations were conducted to determine the intensity of cartilage degeneration. Furthermore, immuno-blotting was performed to evaluate the mitogen-activated protein kinases, PI3K/Akt, and nuclear factor-κB (NF-κB) signaling in rabbit OA models. Histological staining was used to confirm the change in the pattern of collagen and proteoglycan in the articular cartilage matrix. Results: The transplantation of Ellip.+BMSCs elicited a chondroprotective effect by reducing the inflammatory factors (TNF-α, PGE2) in a time-dependent manner. Macroscopic observations, micro-CT, and histological staining revealed articular cartilage regeneration with the downregulation of matrix-metallo proteinases (MMPs), preventing articular cartilage degradation. Furthermore, histological observations confirmed a significant boost in the production of chondrocytes, collagen, and proteoglycan compared to the control group. Western blotting data revealed the downregulation of the p38, PI3K-Akt, and NF-κB inflammatory pathways to attenuate inflammation. Conclusions: The transplantation of Ellip.+BMSCs normalized the OA condition by boosting the recovery of degenerated articular cartilage and inhibiting the catabolic signaling pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.634-641
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• 2016

The objective of this research was to investigate the in vivo effects of treatment with mulberry extract complex (MEC) on cartilage degeneration and pain severity in an experimental model of rat degenerative arthritis. Monosodium iodoacetate ($2mg/50{\mu}L$) was injected into right knee joints of rats, followed by administration of MEC for 8 weeks at 400 mg/kg or 800 mg/kg of body weight. The experimental data show that treatment with MEC inhibited degradation of glycosaminoglycan and collagen in cartilage. On the other hand, concentrations of cartilage oligomeric matrix protein, C-terminal telopeptide-2, matrix metalloproteinase (MMP)-2, MMP-9, and MMP-13 in serum decreased in comparison with the control. The MEC at all dose levels could inhibit formation of xylene-induced ear edema. In this study, MEC demonstrated significant anti-arthritis activity, which is required for improvement of degenerative arthritis. Based on these results, MEC may be employed for the development of new health foods to ease symptoms of degenerative arthritis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.301-308
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• 2013

In this paper, an accuracy analysis of parallel method based on non-overlapping domain decomposition method is carried out. In this approach, proposed by Tak et al.(2013), the decomposed subdomains do not overlap each other and the connection between adjacent subdomains is determined via simple connective finite element named interfacial element. This approach has two main advantages. The first is that a direct method such as gauss elimination is available even in a singular problem because the singular stiffness matrix from floating domain can be converted to invertible matrix by assembling the interfacial element. The second is that computational time and storage can be reduced in comparison with the traditional finite element tearing and interconnect(FETI) method. The accuracy of analysis using proposed method, on the other hand, is inclined to decrease at cross points on which more than three subdomains are interconnected. Thus, in this paper, an accuracy analysis for a novel non-overlapping domain decomposition method with a variety of subdomain numbers which are interconnected at cross point is carried out. The cause of accuracy degradation is also analyze and establishment of countermeasure is discussed.

• Tuberculosis and Respiratory Diseases
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• v.52 no.5
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• pp.453-462
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• 2002

Background : Matrix metalloproteinases(MMPs) are a large family of proteolytic enzymes, which are involved in the degradation of many different components of the extracellular matrix. There is increasing evidence indicating that individual MMPs have important roles in tumor invasion by inactivating the MMPs. In this study, the correlation between MMPs and TIMPs expression, and the clinical outcome was investigated. Materials and Methods : Immunohistochemical staining of MMP-2, 9 and TIMP-1,2 were performed on paraffin-embedded tumor sections from 74 resected primary non-small cell lung cancers. Results : In 74 patients, MMP-2, MMP-9, TIMP-1, and TIMP-2 immunoreactivity was demonstrated in 24(34%), 19(26%) and 32(43%) of the paraffin-embedded tumors, respectively. The median survival of the MMP-2 positive cases was significantly shorter than that of the negative cases(20 vs 34 months). The median survival of the TIMP-2 positive cases was also was significantly longer than that of the negative cases (34 vs 18 months). The MMP-2, and MMP-9 expression level had a positively correlation with a more advanced stage and lymph node metastasis. There was inverse correlation between TIMP-2 expression and tumor invasion. The median survival of the MMP-2 negative/TIMP-2 positive cases was higher than that of the other cases. Conclusion : These results suggest that tumor invasion and lymph node metastasis are closely related to MMP-2 and MMP-9 expression. There was an inverse correlation between TIMP-2 and MMP-9 expression, and tumor invasion.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.129-133
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• 1998

The white-rot fungi Phanerochaete chrysosporium ATCC 24725, Pleurotus ostreatus ATCC 32783, Lentinus edodes ATCC 24462, and Trametes versicolor ATCC 42530 were studied for their ability to degrade lignin, phenanthrene, and anthracene. Lignin in rice-straw was degraded by 14.4, 28.73, and 33.88% by P. chrysosporium, T. versicolor, and P. ostreatus, respectively. Approximately 12% and 83% of phenanthrene was degraded in 1 and 5 days, respectively, when the pre-grown mycelIium matrix of P. ostreatus. was incubated with 10 ppm of phenanthrene in modified Kirk's medium (nitrogen limited) at $25^{\circ}C$. Approximately 2%> and 61% of phenanthrene was degraded when the phenanthrene concentration was increased to 30 ppm. Similar trends were observed with phenanthrene using P. chrysosporium. Mycelial growth of T. versicolor was less inhibited at 30 ppm phenanthrene than for P. ostreatus and P. chrysosporium. Better degradation of phenanthrene by T. versicolor may be attributed to better mycelium growth. One hundred percent of 15 ppm anthracene was degraded in 10 days by both P. chrysosporium and T. versicolor. 40 ppm anthracene inhibited the mycelial growth of P. chrysosporium. lignin peroxidase activity, which was previously reported to be involved in initial phenanthrene oxidation, was also detected from the culture broth of the strains tested. The rates of lignin peroxidase production in the cultures were not consistent with the rate of PAH hydrolysis during incubation.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1567-1573
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• 2020

Ultraviolet (UV) is one of the major factors harmful to skin health. Irradiation with ultraviolet accelerates the decline of skin function, causing the skin to have deep wrinkles, dryness, decreased procollagen production, and degradation of collagen. Novel materials are needed to prevent the aging of the skin by blocking the effects of UV. Safflower seed oil (Charthamus tinctorius L., SSO) contains significantly high levels of unsaturated fatty acids and phytochemicals. SSO has been traditionally used in China, Japan, and Korea to improve skin and hair. Our objective in this study was to determine the effect of SSO and its active compound acacetin on UVB-induced skin photoaging in HaCaT cells and human dermal fibroblasts (HDF). SSO inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) at both protein and mRNA levels in HaCaT cells and HDF. MMP-1 is known to play important roles in collagen degradation and wrinkle formation. Acacetin, a type of flavonoid, is present in SSO. Similar to SSO, acacetin also inhibited UVB-induced MMP-1 protein and mRNA levels in HaCaT cells and HDF. MMP-1 mRNA is primarily regulated by the mitogen-activated kinase (MAPK) signaling pathway. Acacetin regulated the phosphorylation of JNK1/2 and c-jun, but did not inhibit the phosphorylation of ERK1/2, p38 and AKT. Taken together, these results indicate that SSO and its active compound acacetin can prevent UVB-induced MMP-1 expression, which leads to skin photoaging, and may therefore have therapeutic potential as an anti-wrinkle agent to improve skin health.