• Archives of Pharmacal Research
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• 제29권8호
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• pp.712-719
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• 2006

In this study, we prepared core-shell type nanoparticles of a poly(DL-lactide-co-glycolide) (PLGA) grafted-dextran (DexLG) copolymer with varying graft ratio of PLGA. The synthesis of the DexLG copolymer was confirmed by $^1H$ nuclear magnetic resonance (NMR) spectroscopy. The DexLG copolymer was able to form nanoparticles in water by self-aggregating process, and their particle size was around $50\;nm{\sim}300\;nm$ according to the graft ratio of PLGA. Morphological observations using a transmission electron microscope (TEM) showed that the nanoparticles of the DexLG copolymer have uniformly spherical shapes. From fluorescence probe study using pyrene as a hydrophobic probe, critical association concentration (CAC) values determined from the fluorescence excitation spectra were increased as increase of DS of PLGA. $^1H-NMR$ spectroscopy using $D_2O$ and DMSO approved that DexLG nanoparticles have core-shell structure, i.e. hydrophobic block PLGA consisted inner-core as a drug-incorporating domain and dextran consisted as a hydrated outershell. Drug release rate from DexLG nano-particles became faster in the presence of dextranase in spite of the release rate not being significantly changed at high graft ratio of PLGA. Core-shell type nanoparticles of DexLG copolymer can be used as a colonic drug carrier. In conclusion, size, morphology, and molecular structure of DexLG nanoparticles are available to consider as an oral drug targeting nanoparticles.

• 대한기계학회논문집
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• 제11권3호
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• pp.501-508
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• 1987

본 연구에서는 입자발생 장치를 유동층(fluidized bed)을 이용하여 만들었고 이것에 의해서 고온의 연소가스속으로 입자가 공급되므로, 종래의 초음파입자 발생기 나 오리피스진동입자 발생기등에서 일어나는 호학반응 및 입자상호간의 응집(coagul- ation)현상등을 되도록 없게 하여 순수한 구형입자에 대한 입자부착 효과를 볼 수 있 게 함으로써, 부착기구의 이해와 해석등을 한층 유리하게 한다. 그리고 공급되는 입 자의 크기의 범위를 직경 0.2$\mu\textrm{m}$~30$\mu\textrm{m}$ 정도로 광범위하게 다루어 비교적 간단하고 잘 정의된 층류 유동에서, (1) 미세입자의 경우 실시간(real time) 레이져 광반사법에 의 한 입자부착률의 온도구배 및 농도에 대한 효과를 실험하고, (2) 입자의 Counting/Si- zing 법에 의하여 입자크기에 따른 열확산 효과 및 관성충돌 효과 등을 볼 수 있게 한 다.

• 한국초전도ㆍ저온공학회논문지
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• 제16권2호
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• pp.1-6
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• 2014

The five-year national project in Japan for R&D of coated conductors and applications, named as the Materials and Power Applications of Coated Conductors (M-PACC) project, was finished at the end of FY2013. The project consists of four sub-themes as cable, transformer, SMES and coated conductors. In the theme of coated conductors, the fabrication process had been developed to satisfy the requirements from the applications such as in-field $I_c$ performance, low AC loss in the long tapes etc. Through the project, the remarkable progress was achieved as follows; a high in-field minimum $I_c$ value over 54A/cm-width under 3T at 77K was realized in a 200m long EuBCO tape with artificial pinning centers of $BaHfO_3$ by the pulsed laser deposition (PLD) technique on the IBAD template. On the other hand, the AC loss reduction was confirmed in the tapes fabricated by both PLD and the metal organic deposition (MOD) techniques by scribing 100m tapes into 10-filamments. Additionally, the mechanism of the delamination phenomenon was systematically investigated and the strength was improved by eliminating the origins of the weak points in the films. Through the development, all targeted goals were accomplished and the several results were appreciated as a world champion data.

• 한국조경학회지
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• 제22권1호
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• pp.85-100
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• 1994

This study was to analyze the relationship between the community or species and environmental variables of the vegetation landscape in Naejangsan National Park. The analysis was performed by the ordination of DCA and CCA. The study was to compare and analyze the species composition status by the layer and the growth characterisics of the following vegetations ; Torreya nucifera community, Quercus variabilis - Acer palmatum community, Q. variabilis community, Q. variabilis - Sasa purpurascens community and Daphniphyllam macropodum community. The results are as follows; 1. The result of the study on the relationshkp between the stand scores of DCA ordination and environmental variables showed that the soil pH, the ammount of AV-P2O5 and the ammount of C.E.C. tend to increase while Pinus densiflora community changes to Q. variabilis - Q. serrata community and finally Carpinus laxiflora species community siginigicantly. The relation between the stand scores of CCA ordination and several enviromental variables suggested that the species of C. laxiflora and C. tschonoskii the species of Q. cariabilis and Q. serrata the species of C. pisifera, P. densiflora and Q. aliana in sequence grows in more fertile soil. 2. As the result of the analysis of the T. nucifera community showed, reproduction did not increase, and the characteristic of growth was not affected. The result is shown in the growth curve that was damaged by the climate and the human interference. 3. The A. palmatum was found to be as minor species in the middle layer and the crown areas did not have sufficient crown. 4. The result of the analysis of the relationship between Q. variabilis community and Q. variabilis - S. purpurascens community showed a decreasing tendency in the growth and number of species. 5. D. macropodum which constituted the dominance species in the middle layer had a nomal growth curve, and then the successional trend of D. macropodum species seems to be located in the climax species.

• 한국정보통신학회논문지
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• 제11권10호
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• pp.1858-1865
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• 2007

본 논문에서는 위성통신용 IP 모뎀부를 설계 및 구현하였다. 위성 IP모뎀을 위성 의 전송 대역폭, 통신 효율성 등을 고려하여 0.2%의 오버헤드, $E_b/N_o=6dB$에서 $BER=10^{-5}$, 8KHz의 주파수 보정, 1536Kbps 데이터율, 140MHz의 IF 주파수를 갖도록 설계하였다. 설계된 시스템은 시뮬레이션을 통하여 검증하고 MPC86x 통신 프로세서, TMS320C6416 DSP, FPGA 등으로 모듈구조로 구현하여 개발시간의 단축과 성능개선이 용이한 장점을 갖고있다. IP 연동 및 다중 처리를 위한 임베디드 OS로 리눅스를 이용하여 모뎀의 각 하드웨어 에 대한 디바이스 드라이버를 설계하였다. 개발된 하드웨어는 위성 채널 시뮬레이터로 시험하여 검증하였다. 제안된 IP 모뎀은 휴대형으로 설계 되어 어느 곳에서든지 Internet 통신환경을 제공할 수 있다.

• Journal of Veterinary Science
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• 제22권4호
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• pp.55.1-55.17
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• 2021

Background: Naringenin and its glycoside naringin are well known citrus flavonoids with several therapeutic benefits. Although the anti-adipogenic effects of naringenin and naringin have been reported previously, the detailed mechanism underlying their anti-adipogenesis effects is poorly understood. Objectives: This study examined the anti-adipogenic effects of naringenin and naringin by determining differential gene expression patterns in these flavonoids-treated 3T3-L1 adipocytes. Methods: Lipid accumulation and triglyceride (TG) content were determined by Oil red O staining and TG assay. Glucose uptake was measured using a 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose fluorescent d-glucose analog. The phosphorylation levels of AMP-activated protein kinase (AMPK) and acetyl Co-A carboxylase (ACC) were observed via Western blot analysis. Differential gene expressions in 3T3-L1 adipocytes were evaluated via RNA sequencing analysis. Results: Naringenin and naringin inhibited both lipid accumulation and TG content, increased phosphorylation levels of both AMPK and ACC and decreased the expression level of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) in 3T3-L1 adipocytes. RNA sequencing analysis revealed that 32 up-regulated (> 2-fold) and 17 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Scd1, Mogat1, Dgat, Lipin1, Cpt1a, and Lepr, were normalized to the control level in naringenin-treated adipocytes. In addition, 25 up-regulated (> 2-fold) and 25 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Fabp5, Scd1, Srebf1, Hmgcs1, Cpt1c, Lepr, and Lrp1, were normalized to the control level by naringin. Conclusions: The results indicate that naringenin and naringin have anti-adipogenic potentials that are achieved by normalizing the expression levels of lipid metabolism-related genes that were perturbed in differentiated 3T3-L1 cells.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1638-1649
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• 2019

Top soil samples across the state of Kuwait numering ninety were collected and analysed using gamma-ray spectrometry, to evaluate the elemental concentration of $^{238}U$, $^{232}Th$ and $^{40}K$ and their depletion/enrichment. Results of elemental concentration ranges from 0.48 to 2.61 mg/kg, 0.87-5.23 mg/kg, and 0.24-2.23%, with a mean values of 1.39 mg/kg, 3.47 mg/kg, and 1.18%, for the $^{238}U$, $^{232}Th$ and $^{40}K$, respectively. Further analysis was conducted amongst the five identified soil types, i.e. Aquisalids (S1), Calcigypsids (S2), Petrocalcids (S3), Petrogypsids (S4), and torripsamment (S5). The highest radioactivity concentrations from both uranium and thorium were recorded in the S2 (Calcigypsids) soil, with a value of 1.71 (mg/kg) and 4.45 (mg/kg), respectively. Minimum and maximum values of $^{40}K$ are 1.1(%) and 1.27(%) and is prevalent in Aquisalids (S1) and Petrocalcids (S3) soil types, respectively. Ratios of elemental concentration for $^{232}Th/^{238}U$, $^{40}K/^{238}U$, $^{40}K/^{232}Th$ across the soil types are 2.53, 0.09 and 0.03, with a correlation coefficient of 0.92, 0.34, and 0.38, respectively. A progressively higher $^{232}Th/^{238}U$ ratio is observed moving south-wards, indicating lower $^{238}U$ content in soils from the south relative to the northern part. Overall results indicate Kuwait to be relatively an area with low level of natural radioactivity.

• Journal of the Korean Wood Science and Technology
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• 제47권4호
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• pp.509-518
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• 2019

This study analyzed the effect of organic solvent extractives on the classification of wood species via near-infrared spectroscopy (NIR). In our previous research, five species of Korean softwood were classified into three groups (i.e., Cryptomeria japonica (cedar)/Chamaecyparis obtuse (cypress), Pinus densiflora (red pine)/Pinus koraiensis (Korean pine), and Larix kaempferi (Larch)) using an NIR-based principal component analysis method. Similar tendencies of extractive distribution were observed among the three groups in that study. Therefore, in this study, we qualitatively analyzed extractives extracted by an organic solvent and analyzed the NIR spectra in terms of the extractives' chemical structure and band assignment to determine their effect in more detail. Cedar/cypress showed a similar NIR spectra patterns by removing the extractives at 1695, 1724, and 2291 nm. D-pinitol, which was detected in cedar, contributed to that wavelength. Red pine/Korean pine showed spectra changes at 1616, 1695, 1681, 1705, 1724, 1731, 1765, 1780, and 2300 nm. Diterpenoids and fatty acid, which have a carboxylic group and an aliphatic double bond, contributed to that wavelength. Larch showed a catechin peak in gas chromatography and mass spectroscopy analysis, but it exhibited very small NIR spectra changes. The aromatic bond in larch seemed to have low sensitivity because of the 1st overtone of the O-H bond of the sawdust cellulose. The three groups sorted via NIR spectroscopy in the previous research showed quite different compositions of extractives, in accordance with the NIR band assignment. Thus, organic solvent extractives are expected to affect the classification of wood species using NIR spectroscopy.

• 한국가금학회지
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• 제34권4호
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• pp.259-269
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• 2007

본 연구는 브로일러 후기 2주($21{\sim}35$일령) 동안 실험 사료를 섭취한 닭고기에서 DHA 축적 효과 및 저장성을 비교하였다. 로스종 1일령 병아리 수컷 210수를 7개의 처리구로 구분하여 완전 임의 배치하였다. 실험 처리구는 우지를 함유하는 대조구, 어유 1.00% 첨가구(T1), 어유 2.00% 첨가구(T2), 어유 2.00% + 비타민 E 200 ppm + 비타민 C 200 ppm 첨가구(T3), 어유 2.00% + 비타민 C 200 ppm 첨가구(T4), 어유 2.00% + 비타민 E 200 ppm 첨가구(T5) 그리고 어유 3.00% 첨가구(T6)로 구분하였다. 닭고기 내 DHA 축적량은 모든 부위에서 T6가 가장 높았고, 다리살(닭 껍질포함)과 가슴살 근육에서 T1이 $T2{\sim}T5$ 보다 약간 높았으나, 생통닭과 날개(닭 피부 포함)에서 $T2{\sim}T5$는 T1 보다 약 2배 가까이 높은 축적율을 나타냈다. 저장 일수에 따른 닭고기의 DHA 조성은 T1, T2 및 T6가 42.30%, 49.38%, 48.51% 감소하였으며, 이들은 T3, T4, T5에 비해서 유의적으로 높은 감소를 나타냈다(p<0.05). 특히 TBARS의 값이 가장 낮은 T3와 T5에서 가장 낮은 DHA 감소율을 나타냈다. TBARS는 저장 일수가 지남에 따라서 T6, T2, T1 순서로 증가하였고, T3, T5, T4 순서로 낮았으며, 각 처리구간 통계적인 유의차가 있었다(p<0.05).

• 치위생과학회지
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• 제14권2호
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• pp.150-157
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• 2014

본 연구에서는 기존에 임상에서 염색제를 사용한 치면세균막검사와 periodental probe를 사용한 치은지수 평가방법대신 새로운 디지털 형광 장비인 QLF-D를 이용한 검사법의 활용 가능성을 확인하고자 하였다. 염색제를 이용하여 치면세균막지수를 산출하여 연구 대상자를 위험군별로 구분하여 일반적 특성을 확인하였고, 분석 소프트웨어를 이용하여 산출되는 QLF-D score와 전체 및 전치부 치면세균막지수, 치은지수의 상관성을 확인하였다. 정상치은과 치은염에 따른 QLF-D score를 비교하였고, 각 QLF-D score에 따른 치면세균막지수와 치은지수의 평균값을 비교하여 다음과 같은 결론을 내렸다. 연구대상자의 염색제를 이용한 평균 치면세균막지수는 $42.28{\pm}17.90$이었고, 6개의 선택치아의 치은지수는 $1.05{\pm}20.38$로 나타났으며, QLF-D score는 $1.26{\pm}1.50$이었다. 상하악전치부 QLF-D score와 치면세균막염색을 이용하여 평가한 전치부 치면세균막지수의 상관 분석 결과, 유의한 양의 상관관계를 확인하였다(r=0.638, p<0.001). 또한 상하악 전치부 QLF-D score와 periodontal probe를 이용한 치은지수와의 관계를 분석한 결과에서도 두 가지 평가 지표 간에 유의한 양의 상관관계를 보였다(r=0.562, p<0.001). 치면세균막지수와 치은지수에 따른 QLF-D score의 차이를 저위험군과 고위험군으로 분류하여 비교한 결과, 치면세균막지수(p<0.0001)와 치은지수(p=0.007) 모두 저위험군에 비해 고위험군 집단에서 QLF-D score가 통계적으로 유의하게 높았다. QLF-D score에 따른 치면세균막지수 및 치은지수 평균값을 비교한 결과, QLF-D score가 증가할수록 두 가지 지수 모두 통계적으로 유의하게 증가하는 양상을 보였다(p<0.0001). 이와 같은 결과를 통해, QLF-D로 치면세균막을 평가함으로써 치은상태를 모니터링 하는 것이 가능함을 확인하였다. 이를 통해 임상 현장에서 QLF-D를 활용한다면, 비교적 간편하게 구강 이미지를 획득하고 구강 상태를 점수화하여 제시함으로써 술자의 진단 절차가 간편해지고 환자와의 의사소통이 원활해질 수 있을 것으로 사료된다.