• Biomedical Science Letters
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• v.10 no.2
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• pp.143-151
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• 2004

Matrix metalloproteinases (MMPs) are capable of degrading extracellular matrix, a process that is necessary for angiogenesis, tumor invasion and metastasis. Platelet-activating factor (PAP) increases angiogenesis, tumor growth and metastasis through nuclear factor (NF)-$\kappa$B activation. Based on these facts, the involvement of MMPs in PAF-induced pulmonary metastasis was investigated in murine sarcoma cells, MMSV-BALB/3T3. Messenger RNA expression and enzymatic activity of MMP-9 were assessed by RT-PCR and zymography, and cell migration and metastasis were done for the detection of MMP-9 functional activity. PAP induced mRNA expression and enzymatic activity of MMP-9, and its effects were either inhibited by the PAP antagonist, WEB 2170 or by the NF-$\kappa$B inhibitor, parthenolide, or p65 antisense oligonucleotide in a dose-dependent manner. In addition, PAF induced promoter activity of MMP-9, which was inhibited by WEB 2170, phenanthroline, NAC, PDTC. These results indicate that PAF induces mRNA expression and enzymatic activity of MMP-9 in NF-$\kappa$B dependent manner. Cell migration assay showed that PAF induced MMSV-BALB/3T3 migration, and its effect was significantly inhibited by treatment with phenanthroline. PAF enhanced pulmonary metastasis of murine sarcoma cells, MMSV-BALB/3T3 was also reduced by phenanthroline. These results suggest that PAF-enhanced cell migration and pulmonary metastasis is mediated through the expression of MMP. In conclusion, It is suggested that PAF enhances pulmonary metastasis by inducing MMP-9 expression via the activation of NF-$\kappa$B.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.617-624
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• 2007

Insulin-like growth factor(IGF) is the most abundant growth factor in bone matrix. Recent studies have shown that it can sensitize apoptotic cell death of osteoblasts. Thus, this study investigated whether IGF-II aggravates irradiation-induced cell death of osteoblasts. Cultured MC3T3 osteoblasts were irradiated and IGF-II was added at the concentration of 50 ng/ml immediately after the irradiation. Cell viability was measured by MTT assay. Changes in cell death and cell cycle were analyzed by flow cytometry. The expression of proapoptotic gene bax and antiapoptotic gene bcl-2 was quantified by real time RT-PCR and Western blot. A dose of 30 Gy caused G2/M arrest and increased cell death through both necrosis and apoptosis, while irradiation from 4 to 10 Gy little affected cell cycle and death. IGF-II treatment reduced cell viability without stimulating cell proliferation and changing cell cycle. Combined treatment of IGF-II with irradiation decreased cell viability and proliferation and increased cell death along with G2/M arrest. These effects were not different from those of irradiation only. At transcriptional and protein levels, IGF-II treatment did not affect bax and bcl-2 expression, whereas irradiation increased the expression ofbax without changes in bcl-2. IGF-II in combination with irradiation showed similar findings. These results suggest that IGF-II could modulate apoptotic cell death through mechanisms other than an imbalance between bax and bcl-2 gene expression, although its effect was overridden by irradiation.

• Biomedical Science Letters
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• v.8 no.4
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• pp.229-234
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• 2002

Chlorella is rich in chlorella growth factor (CGF). A review of the literature has described that CGF improves the capability of a Th1-based immunity, anticancer, antioxidant antibacterial activity, growth promotion, wound healing and so on, but has not studied the effect for the metabolism and the proliferation of human skin keratinocyte. The aim of this study was to examine the effect of metabolism and the proliferation of human skin keratinocyte in vitro. CGF was extracted with an autoclaving method which is a modified hot-water extraction method from dried chlorella and conformed by means of absorbance 0.22 at 260 nm. We have measured the extracellular acidification rate (ECAR) of the CGF by Cytosensor$^{\circledR}$ Microphysiometer and evaluated responsiveness depending upon the dosage on the HaCaT cell. The ECAR for the concentrations of 0.15, 1.5, 15, 150 $\mu\textrm{g}$/ml of CGF increased as a 103.6, 128.2, 149.0 and 423.9%, respectively compared to control (0.0 $\mu\textrm{g}$/ml, 100% ECAR). The ECAR for ErbBl tyrosine kinase inhibited by 4-anilinoquinazolines, $C_{16}$H$_{14}$BrN$_3$O$_2$.HCl on tile HaCaT cells with the amounts of 10 $\mu\textrm{g}$/ml of the CCF compared with 100 $\mu\textrm{g}$/ml of rhEGF. The conclusion of the study is that CGF might increase human epidermal keratinocyte proliferation through the interaction between the epidermal growth factor receptor and itself.

• Journal of Preventive Medicine and Public Health
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• v.46 no.1
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• pp.28-38
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• 2013

Objectives: This study aimed to collect information that will help enhance the social networks and improve the quality of life among elderly people by observing the relationship between their social network and health-related quality of life (HRQoL) and by analyzing social network factors affecting HRQoL. Methods: This study was based on the 2008 Community Health Survey in Yeoncheon County. Three hundred elders were included in the study population. We compared the revised Lubben Social Network Scale (LSNS-R) score and Euro quality of life-5 dimensions health status index by demographic characteristics and chronic disease prevalence. We analyzed the data using multiple regression and tobit regression by setting the HRQoL as the dependent variable and social network and other characteristics as the independent variables. We analyzed social network factors by using factor analysis. Results: The LSNS-R score differed significantly according to age and existence of a spouse. According to the results from the hierarchical multiple regression analysis, the LSNS-R explained 0.10 of the variance and LSNS-R friends factor explained 0.10 of the variance. The tobit regression indicated that the contribution of the LSNS-R family size factor to the regression coefficient of the independent variable that affected the HRQoL was $B_T$=2.96, that of the LSNS-R family frequency factor was $B_T$=3.60, and that of LSNS-R friends factor was $B_T$=5.41. Conclusions: Social networks among elderly people had a significant effect on HRQoL and their networks of friends had a relatively higher effect than those of family members.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.539-546
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• 1999

A new integrated single-stage zero current switched(ZCS) quasi resonant convertedQRC) for the IX)wer f factor correction(PFCl converter is introduced in this paper. The power factor correction can be achieved by t the discontinuous conduction mod$\varepsilon$(DCM) operation of an input current. The proposed converter has the c characteristics of the good IX)wer factor, 10씨 line current harmonics, and tight output regulation. Furthern10re, t the ringing effect due to the output capacitance of the main switch can be eliminated by use of‘ active clamp c circuit. Therefore, the proIX)sed converter is expecttc'(] to be suitable for a compact power converter with a t tightly regulated output voltage requiring a switching frequency of more than several hundrtc'(]s kHz.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.437-442
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• 2017

Previously, studies on compensation material to increase the signal intensity have been conducted which does not affect the reading of images. However, the compensation material has a concern on patient infection as it is attached directly on the skin. Therefore, in this study, we tested an indirect attachment of the compensation material as an alternative method of the direct attachment. The silicon compensation material was fabricated in the form of a cylindrical bar and attached to each element of the 8 channel head coil. Then the signal intensities of the water phantom pre and post application of the silicon were measured. T1 and T2-weighted images were acquired using an 8-channel head coil and a 3.0T superconducting MRI. Signal intensities were measured by using an image measuring program. Paired t-test was used to verify if there were significant differences. The signal intensity before application of the silicon was significantly increased by 3.39% and 2.62% in T1 and T2 weighted images, respectively. Although the indirect attachment method had a limitation to completely replace the existing method, it was considered to be useful in patients with infectious diseases such as diabetic complications since it had a meaningful improvement in signal intensity based on the filling factor increase.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.135-140
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• 2015

Trans-10, cis-12-conjugated linoleic acid (t10c12-CLA) has been shown to participate in the regulation of anti-inflammatory effects. The objectives of this study were to examine the effects of t10c12-CLA on reactive oxygen species (ROS) and nitric oxide (NO) production and nuclear factor-kappaB (NF-${\kappa}B$) activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and to determine whether these effects were associated with change of intracellular calcium ion ($Ca^{2+}$). ROS production was increased in LPS-stimulated RAW 264.7 cells, and this effect was suppressed by 1,2-bis-(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM), a calcium chelator. t10c12-CLA suppressed ROS production in LPS-stimulated RAW 264.7 cells, which was further more decreased by treatment with BAPTA/AM. These indicated that t10c12-CLA decreases $Ca^{2+}$-dependent ROS production in LPS-stimulated RAW 264.7 cells. Similarly, NF-${\kappa}B$ p65 DNA binding activity and NO production were decreased by treatment with either t10c12-CLA, BAPTA/AM, or t10c12-CLA and BAPTA/AM combination. However, there were no differences between t10c12-CLA and BAPTA/AM treatment in NO production of LPS-stimulated RAW 264.7 cells. These data indicate that t10c12-CLA inhibits the increases in ROS and NO production and the NF-${\kappa}B$ activation in LPS-stimulated condition. These results suggested that CLA exerts potent anti-inflammatory effects by suppression of LPS-induced ROS and NO production, and NF-${\kappa}B$ activationn via $Ca^{2+}$-dependent pathway.

• Korean Journal of Psychosomatic Medicine
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• v.6 no.2
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• pp.155-175
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• 1998

The purpose of this study was to test a reliability and validity of the Korean version of Eating Attitudes Test-26(KEAT-26). Using multi-stage sampling, we finally got 3,496 subjects(1422 males and 2074 females) who were available for analysis from target 4,400 Korean adults over 18 in the nationwide areas of9 kus, 10 middle or small cities, and 17 kuns. We tried to make T score norm of the KEAT-26 as a cutoff score and STEN score norm as a index of severity for disordered eating behaviors. For the male group, Cronhach's internal consistency was .83 and Spearman-Brown split half correlation coefficiency was .75. For the female group, each of them was .81 and .75, and .81, .75 for the grand total group respectively. Validity test was performed by construct validation analysis. By a iterated principal axis factoring, 4 factors were extracted. There were some differences in the factors of the KEAT-26 by sex. In the male group, factor I was 'self-control of eating and bulimic symptom', factor II was 'food preoccupation and dieting', factor III was 'preoccupation with being thinner', factor N was 'avoidance of sweet foods'. In contrast with the male group, factor I was 'self-control of eating and bulimic symptom', factor II was 'preoccupation with being thinner', factor III was 'food preoccupation' and factor N was 'dieting' in the female group. We used T score 65 as a cutoff score. T score 65 corresponded to raw score 19 in the male group, 22 in the female group and 21 in the grand total group. Severity of disordered eating behaviors was measured by a STEN score. In the male group, each of the score range of 0-10, 11-14, 15-18, 19-22 and over 23 represented the degree of none, subclinical, manifest, moderate and severe severity respectively. Each of the score range of 0-13, 14-17, 18-21, 22-26 and over 27 in the female group, and the score range of 0-12, 13-16, 17-20, 21-25 and over 26 in the grand total group also represented the same degree of severity as like in the male group. These results support that KEAT-26 is a reliable and valid scale for evaluating disordered eating behaviors and eating problems.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.3 s.28
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• pp.373-382
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• 1988

The purpose of this study is to compare the image discrepancy with Korean clothing and Western clothing using semantic differential scales. 19 adjective pairs were used for this study. The survey questionnaire were given to 946 married - women in Seoul. For the statistical analysis frequency, percentage, mean, ANOVA, t-test and Factor analysis were used. T he major findings were as follows: 1. To evaluate the women's clothing, four major factors were obtained and it was found that women evaluated quite differently their dresses with Korean and western styles. 2. The major evaluating factor of Korean dress was aesthetic aspect and on the other hand the main factor of western dress was functional aspect.

• Bulletin of the Korean Mathematical Society
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• v.52 no.2
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• pp.581-591
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• 2015

Let $\mathcal{A}$ be a factor von Neumann algebra with dimension greater than 1. We prove that if a linear map ${\delta}:\mathcal{A}{\rightarrow}\mathcal{A}$ satisfies $${\delta}([[a,b],c])=[[{\delta}(a),b],c]+[[a,{\delta}(b),c]+[[a,b],{\delta}(c)]$$ for any $a,b,c{\in}\mathcal{A}$ with ab = 0 (resp. ab = P, where P is a fixed nontrivial projection of $\mathcal{A}$), then there exist an operator $T{\in}\mathcal{A}$ and a linear map $f:\mathcal{A}{\rightarrow}\mathbb{C}I$ vanishing at every second commutator [[a, b], c] with ab = 0 (resp. ab = P) such that ${\delta}(a)=aT-Ta+f(a)$ for any $a{\in}\mathcal{A}$.