• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.499-506
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• 1992

Copolymer of Styrene and GMA(glycidyl methachylate), having reactive ratios of $r_1=0.53$, $r_2=0.44$, was synthesized in dioxane using AIBN as free radical initiator. Followed by the reaction of ethylene diamine with copolymer PGS, amine groups were introduced to the PGS(NPGS). The composition of copolymer was determined by elemental analyzer. Poly(glycidyl methacrylate) (PGMA) was obtained in benzene using AIBN as free radical initiator. The NPGS-PGMA blend of 50/50 composition was prepared by mixing these polymers in THF at $65^{\circ}C$. Glass transition temperature (Tg) of NPGS-PGMA blend was measured by DSC. The blend showed a single Tg. Accordingly, it was clear that the NPGS was compatible with PGMA. An intermolecular reaction between amine groups of NPGS and epoxy groups of PGMA imparts compatibility in the NPGS-PGMA blend. When the NPGS-PGMA blend was added to the incompatible PS-PGMA blend, PS-PGMA blend showed Tg change. Scanning Electron Micrograph(SEM) showed a fine morphology in this blend. Consequently, it was apparent that the NPGS-PGMA blend acted as a compatibilizer for the PS-PGMA blend.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.193-201
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• 2000

Prostaglandins (PGs) and Leukotrienes (LTs) have been implicated in the genesis of pulpal and periapical inflammation. In this study, the relationships among $PGE_2$, 6-keto-PG $F_1{\alpha}$ (a stable metabolite of $PGI_2$) and $LTB_4$ concentrations in inflamed pulp and periapical lesions were discussed. Pulp tissue were obtained in routine endodontic treatment and periapical lesions in periapical surgery after clinical diagnoses were made. These specimens were divided into four groups as normal pulp group (Control group), acute pulpitis group, chronic pulpitis group, and periapical lesion group. Pulp tissue and periapical lesions were stored in liquid nitrogen. The concentration of $PGE_2$, $PGI_2$ and $LTB_4$ were measured with ELISA. The data were analyzed by one-way ANOVA. Significantly higher levels of $PGE_2$, 6-keto-PG $F_1{\alpha}$ a and $LTB_4$ were found in acute pulpitis group than chronic pulpitis group and periapical lesion group(p<0.05). Periapical lesion group showed significantly higher mean concentrations of $PGE_2$ and $LTB_4$ than chronic pulpitis group. In control and chronic pulpitis group, significant higher levels of $PGI_2$ than $PGE_2$ and $LTB_4$ were found. These results suggested that the high levels of $PGE_2$ and $LTB_4$ in periapical lesions may be due to rich endothelium., fibroblast and lymphocyte known as the main producers of $PGE_2$ and $LTB_4$. $PGI_2$ may be thought to one of the most abundant PGs in normal pulp tissue.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.626-636
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• 2021

Boron-neutron capture therapy (BNCT) is a cancer treatment method that exploits the high neutron reactivity of boron. Monitoring the prompt gamma rays (PGs) produced during neutron irradiation is essential for ensuring the accuracy and safety of BNCT. We investigate the imaging of PGs produced by the boron-neutron capture reaction through Monte Carlo simulations of a gamma camera with a SrI₂ scintillator and parallel-hole collimator. GAGG scintillator is also used for a comparison. The simulations allow the shapes of the energy spectra, which exhibit a peak at 478 keV, to be determined along with the PG images from a boron-water phantom. It is found that increasing the size of the water phantom results in a greater number of image counts and lower contrast. Additionally, a higher septal penetration ratio results in poorer image quality, and a SrI₂ scintillator results in higher image contrast. Thus, we can simulate the BNCT process and obtain an energy spectrum with a reasonable shape, as well as suitable PG images. Both GAGG and SrI₂ crystals are suitable for PG imaging during BNCT. However, for higher imaging quality, SrI₂ and a collimator with a lower septal penetration ratio should be utilized.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.87-93
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• 2013

Objectives : Degenerative arthritis arises from several physiological factors. The purpose of this study is to investigate the beneficial effects of Phyto-extract Complex (CME) on degenerative arthritis. Methods : CME is composed of extracts of mulberry (Morus alba L.) fruit, mulberry leaves and black beans (Glycine max (L.) Merr.). To measure the toxicity of CME, we performed the single-dose toxicity study. For the evaluation of its effects on degenerative arthritis, we examined the inhibition of cyclooxygenase-2 (COX-2) activity, using in vitro enzyme activity assay, the reduction of protein expression of COX-2, 5-lipoxygenase (5-LO), and inducible nitric oxide synthase (iNOS) in RAW264.7 cells which were stimulated by lipopolysaccharide (LPS). We also examined the serum level of prostaglandins (PGs) and injury of the knee joint cartilage, using animal model of degenerative arthritis induced by mono-sodium iodoacetate (MIA). Results : CME did not have any toxicity in single-dose toxicity study. The CME inhibited the activity of COX-2 and could reduce the protein expression of COX-2, 5-LO and iNOS in RAW264.7 cells. The CME also reduced the serum level of PGs and prevented from the cartilage injury of knee joint in animal model of degenerative arthritis induced by MIA. Conclusions : Taken altogether, the CME could be useful for the improvement of degenerative arthritis through its various anti-inflammatory activities and prevention from the cartilage injury of knee joint.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.3
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• pp.62-74
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• 2010

This study aims to examine what factors citizens value in urban parks and green spaces in terms of usage and aesthetic value and to find ways to deal with the changing patterns of user satisfaction for these various green elements. To achieve this, the study developed a dynamic model employing a transactional approach to evaluate environmental quality for 1999 and 2007 in Anyang City as well as a conceptual model of parks and greens satisfaction. This study relied on an empirical study method including the 1999 and 2007 green conditional survey and citizen questionnaires totaling 573 in the year 1999 and 982 in the year 2007. As a result, first, the factor 'urban parks' is the most important factor and 'cityscape' is the second most important factor in parks and greens satisfaction(PGS). Second, PGS in turn causes environmental quality satisfaction(EQS), which is related to two items--'urban livability' and 'aesthetic quality'--in the model. This means that PGS is the intervening variable of urban livability. Third, the factor analysis resulted in six factors: cityscape, urban green, linear facilities, urban parks, riverside green, and urban forest. 'Riverside green' emerged as a factor in 2007 as a result of public participation in the 'Anyang River Revitalization Project'. Fourth, through a transactional view, the environmental changes result in either a change in or stability of public attitude. The levels of satisfaction were elevated but patterns of satisfied-unsatisfied items remained unchanged for most factors. The perception of riverside a greenway and linear surface facilities(pedestrian walkways, biking and jogging trails, etc.) have changed positively. PGS changed significantly in 2007, as a result of urban events and development, including parks, rivers and greenways which were built through the joint effort of the local government and civic participation.

• BMB Reports
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• v.47 no.6
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• pp.348-353
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• 2014

The speed of sound (SOS) value is an indicator of bone mineral density (BMD). Previous genome-wide association (GWA) studies have identified a number of genes, whose variations may affect BMD levels. However, their biological implications have been elusive. We re-analyzed the GWA study dataset for the SOS values in skeletal sites of 4,659 Korean women, using a gene-set analysis software, GSA-SNP. We identified 10 common representative GO terms, and 17 candidate genes between these two traits (PGS < 0.05). Implication of these GO terms and genes in the bone mechanism is well supported by the literature survey. Interestingly, the significance levels of some member genes were inversely related, in several gene-sets that were shared between two skeletal sites. This implies that biological process, rather than SNP or gene, is the substantial unit of genetic association for SOS in bone. In conclusion, our findings may provide new insights into the biological mechanisms for BMD.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.483-490
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• 2011

Using a coplanar waveguide employing periodic ground structure (PGS) on silicon substrate, a highly miniaturized and broadband impedance transformer was developed for application to low impedance matching in broadband. Concretely, the multi-section transformer was designed using Chebyshev polynomials design technique for ultra broadband operation. Its size was 0.026 $m^2$ on silicon substrate, which was 8.7 % of the one fabricated by conventional coplanar waveguide on silicon substrate. The transformer showed a good RF performance over a ultra broadband from 8 - 49.5 GHz.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.209.2-210
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• 2003

Nitric oxide (NO) and prostagladins(PGs) produced by inducible nitric oxide synthase(iNOS) and cyclooxygenase(COX-2) are known as inflammatory mediator. Modulation of these enzymes, induced by many stimuli(LPS, IFN-gamma, TNF-alpha, phorbol ester, etc), is a potent strategy as treatment of inflammatory diseases. Treatment of murine macrophage RAW 264.7 cell line with indole compound(IND-6) markedly reduced lipopolysacchride(LPS) stimulated NO production in a concentration-related manner. (omitted)

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.562-568
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• 2009

In this paper, using the periodic ground structure (PGS), highly miniaturized branch-line coupler and impedance transformer were realized on Si radio frequency integrated circuit (RFIC). The branch-line couple exhibited good RF performance from 41.75 to 50 GHz, and its size was $0.46{\times}0.55mm^2$, which is 37 % of conventional one. The impedance transformer exhibited good RF performance from 1 to 40GHz, and its size was $0.01mm^2$, which is 6.99 % of conventional one.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.153-157
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• 2006

본 논문에서는 SoC 공정에 적용 가능한 spiral 인덕터의 특성에 대해 다루었다. 일정한 크기의 인덕터에서 턴 수의 변화에 따른 인덕턴스와 Q-factor의 변화를 보았다. HFSS 프로그램을 사용하여 턴 수와 선로의 폭이 같은 조건하에서 사각형 구조와 팔각형 구조를 갖는 인덕터의 인덕턴스와 Q-factor의 ?냅? 계산하였다. 사각형 구조와 팔각형 구조 모두 선로 폭 보다는 턴 수가 증가할수록 인덕턴스가 증가하였다. 턴 수가 증가할수록 Q-factor의 값은 사각형 구조는 감소한 반면 팔각형 구조는 증가하였다. spiral과 실리콘 사이에 PGS(Patterned Ground Shield)를 삽입하여 인덕턴스 및 Q-factor의 변화를 비교 분석하였다. 그 결과 PGS의 사용으로 사각형 구조와 팔각형 구조에서 턴 수에 따라 Q-factor의 값이 구조에 따라 서로 다른 방향으로 증감하는 것을 확인할 수 있었다.