• Title/Summary/Keyword: Cluster Formation

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Adzuki bean (Vigna angularis) extract reduces amyloid-β aggregation and delays cognitive impairment in Drosophila models of Alzheimer's disease

  • Miyazaki, Honami;Okamoto, Yoko;Motoi, Aya;Watanabe, Takafumi;Katayama, Shigeru;Kawahara, Sei-ichi;Makabe, Hidefumi;Fujii, Hiroshi;Yonekura, Shinichi
    • Nutrition Research and Practice
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    • v.13 no.1
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    • pp.64-69
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    • 2019
  • BACKGROUND/OBJECTIVES: Alzheimer's disease is a neurodegenerative disease that induces symptoms such as a decrease in motor function and cognitive impairment. Increases in the aggregation and deposition of amyloid beta protein ($A{\beta}$) in the brain may be closely correlated with the development of Alzheimer's disease. In this study, the effects of an adzuki bean extract on the aggregation of $A{\beta}$ were examined; moreover, the anti-Alzheimer's activity of the adzuki extract was examined. MATERIALS/METHODS: First, we undertook thioflavin T (ThT) fluorescence analysis and transmission electron microscopy (TEM) to evaluate the effect of an adzuki bean extract on $A{\beta}_{42}$ aggregation. To evaluate the effects of the adzuki extract on the symptoms of Alzheimer's disease in vivo, $A{\beta}_{42}$-overexpressing Drosophila were used. In these flies, overexpression of $A{\beta}_{42}$ induced the formation of $A{\beta}_{42}$ aggregates in the brain, decreased motor function, and resulted in cognitive impairment. RESULTS: Based on the results obtained by ThT fluorescence assays and TEM, the adzuki bean extract inhibited the formation of $A{\beta}_{42}$ aggregates in a concentration-dependent manner. When $A{\beta}_{42}$-overexpressing flies were fed regular medium containing adzuki extract, the $A{\beta}_{42}$ level in the brain was significantly lower than that in the group fed regular medium only. Furthermore, suppression of the decrease in motor function, suppression of cognitive impairment, and improvement in lifespan were observed in $A{\beta}_{42}$-overexpressing flies fed regular medium with adzuki extract. CONCLUSIONS: The results reveal the delaying effects of an adzuki bean extract on the progression of Alzheimer's disease and provide useful information for identifying novel prevention treatments for Alzheimer's disease.

A Study on Policy Trends and Location Pattern Changes in Smart Green-Related Industries (스마트그린 관련 산업의 정책동향과 입지패턴 변화 연구)

  • Young Sun Lee;Sun Bae Kim
    • Journal of the Economic Geographical Society of Korea
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    • v.27 no.1
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    • pp.38-52
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    • 2024
  • Digital transformation industry contributes to the improvement of productivity in overall industrial production, the smart green industry for carbon neutrality and sustainable growth is growing as a future industry. The purpose of this paper is to explore the status and role of the industry in the future industry innovation ecosystem through the analysis of the growth drivers and location pattern changes of the smart green industry. The industry is on the rise in both metropolitan and non-metropolitan areas, and the growth of the industry can be seen in non-metropolitan and non-urban areas. In particular, due to the smart green industrial complex pilot project, the creation of Gwangju Jeonnam Innovation City, and the promotion of new and renewable energy policies, the emergence of core aggregation areas (HH type) in the coastal areas of Honam and Chungcheongnam-do, and the formation of isolated centers (HL type) in the Gyeongsang region, new and renewable energy production companies are being accumulated in non-metropolitan areas. Therefore, the smart green industry is expected to promote the formation of various specialized spokes in non-urban areas in the future industrial innovation ecosystem that forms a multipolar hub-spoke network structure, where policy factors are the triggers for growth.

NUMERICAL ANALYSIS FOR TURBULENT FLOW AND AERO-ACOUSTICS AROUND A THREE DIMENSIONAL CAVITY WITH HIGH ASPECT RATIO (3차원 고세장비 공동 주위의 난류유동 및 음향 특성에 관한 수치적 연구)

  • Mun, P.U.;Kim, J.S.
    • Journal of computational fluids engineering
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    • v.15 no.2
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    • pp.7-13
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    • 2010
  • Flight vehicles such as wheel wells and bomb bays have many cavities. The flow around a cavity is characterized as an unsteady flow because of the formation and dissipation of vortices brought by the interaction between the free stream shear layer and the internal flow of the cavity. The resonance phenomena can damage the structures around the cavity and negatively affect the aerodynamic performance and stability of the vehicle. In this study, a numerical analysis was performed for the cavity flows using the unsteady compressible three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equation with Wilcox's turbulence model. The Message Passing Interface (MPI) parallelized code was used for the calculations by PC-cluster. The cavity has aspect ratios (L/D) of 5.5 ~ 7.5 with width ratios (W/D) of 2 ~ 4. The Mach and Reynolds numbers are 0.4 ~ 0.6 and $1.6{\times}10^6$, respectively. The occurrence of oscillation is observed in the "shear layer and transient mode" with a feedback mechanism. Based on the Sound Pressure Level (SPL) analysis of the pressure variation at the cavity trailing edge, the dominant frequencies are analyzed and compared with the results of Rossiter's formula. The dominant frequencies are very similar to the result of Rossiter's formula and other experimental datum in the low aspect ratio cavity (L/D = ~4.5). In the high aspect ratio cavity, however, there are other low dominant frequencies of the leading edge shear layer with the dominant frequencies of the feedback mechanism.

Infrared and Radio observations of a small group of protostellar objects in the molecular core, L1251-C

  • Kim, Jungha;Lee, Jeong-Eun;Choi, Minho;Bourke, Tyler L.;Evans II, Neal J.;Di Francesco, James;Cieza, Lucas A.;Dunham, Michael M.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.67.4-68
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    • 2015
  • We present a multi-wavelength observational study of a low-mass star-forming region, L1251-C, with observational results at wavelengths from the near-infrared to the millimeter. Spitzer Space Telescope observations confirmed that IRAS 22343+7501 is a small group of protostellar objects. The extended emission to east-west direction with its intensity peak at the center of L1251A has been detected at 350 and 850 mm with the CSO and JCMT telescopes, tracing dense envelope materials around L1251A. The single-dish data from the KVN and TRAO telescopes show inconsistencies between the intensity peaks of several molecular line emission and that of the continuum emission, suggesting complex distributions of molecular abundances around L1251A. The SMA interferometer data, however, show intensity peaks of CO 2-1 and $^{13}CO$ 2-1 located at the position of IRS 1, which is both the brightest source in IRAC image and the weakest source in the 1.3 mm dust continuum map. IRS 1 is the strongest candidate for being the driving source of a newly detected the compact CO 2-1 outflow. Over the whole region ($14^{\prime}{\times}14^{\prime}$) of L125l-C, 3 Class I and 16 Class II sources have been detected, including three YSOs in L1251A. A comparison with the average projected distance among 19 YSOs in L1251-C and that among 3 YSOs in L1251A suggests L1251-C is an example of low-mass cluster formation, where protostellar objects are forming in a small group.

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NUMERICAL ANALYSIS FOR TURBULENT FLOW OVER A THREE DIMENSIONAL CAVITY WITH LARGE ASPECT RATION (세장비 변화에 따른 3차원 공동 주위의 난류유동 및 음향 특성에 관한 수치적 연구)

  • Mun, P.U.;Kim, J.S.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.13-18
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    • 2009
  • Flight vehicles such as wheel wells and bomb bays have many cavities. The flow around a cavity is characterized as an unsteady flow because of the formation and dissipation of vortices brought about by the interaction between the free stream shear layer and the internal flow of the cavity. The resonance phenomena can damage the structures around the cavity and negatively affect the aerodynamic performance and stability of the vehicle. In this study, a numerical analysis was performed for the cavity flows using the unsteady compressible three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equation with Wilcox's turbulence model. The Message Passing Interface (MPI) parallelized code was used for the calculations by PC-cluster. The cavity has aspect ratios (L/D) of 2.5 ~ 7.5 with width ratios (W/D) of 2 ~ 4. The Mach and Reynolds numbers are 0.4 ~ 0.6 and $1.6{\times}106$, respectively. The occurrence of oscillation is observed in the "shear layer and transient mode" with a feedback mechanism. Based on the Sound Pressure Level (SPL) analysis of the pressure variation at the cavity trailing edge, the dominant frequencies are analyzed and compared with the results of Rossiter's formula. The dominant frequencies are very similar to the result of Rossiter's formula and other experimental data in the low aspect ratio cavity (L/D = ~ 4.5). In the large aspect ratio cavity, however, there are other low dominant frequencies due to the leading edge shear layer with the dominant frequencies of the feedback mechanism. The characteristics of the acoustic wave propagation are analyzed using the Correlation of Pressure Distribution (CPD).

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Characteristics and oxidation behavior of the hybrid-HVOF sprayed $Cr_3C_2$-7wt%(NiCr) coatings depending on $H_2/O_2$ ratio ($H_2/O_2$ 비에 따른 Hybrid HVOF 용사된 $Cr_3C_2$-7wt%(NiCr) 용사층의 특성 및 산화거동)

  • 김병희;서동수
    • Journal of Welding and Joining
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    • v.15 no.4
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    • pp.126-135
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    • 1997
  • $H_2/O_2$ 비에 따른 Hybrid HVOF 용사된 $Cr_3C_2$-7wt%(NiCr) 용사층의 특성 및 산화거동 This study was performed to investigate the influence of fuel/oxygen ratio (F/O=3.2, 3.0, 2.8) on the characteristics and the oxidation behavior of the hybrid-HVOF sprayed $Cr_3C_2$-7wt%NiCr coatings. Decomposition and the oxidation of the $Cr_3C_2$was occured during spraying. The degree of transformation from $Cr_3C_2$to $Cr_7C_3$ was increased with decreasing the F/O ratio. The microstructural differences of the as sprayed coating with F/O ratio can not be distinguished, However, large pores were diminished and then the coatings became dense by heat treatment. Microhardness of the as-sprayed specimen which sprayed with F/O=3.0 condition was hightest ($Hv_{300}$=1140) and the hardness was increased to 1500 after heat treatment at $600^{\circ}C$ for 50hrs in air. It was supposed that hardness was increased due to the formation of $Cr_2O_3$ within $Cr_3C_2$/$Cr_7C_3$matrix and the densification of coating layer during heat treatment. Apparent activation energy for oxidation was varied from 21.2 kcal$mol^{-1}K^{-1}$ to 23.8 kcal$mol^{-1}K^{-1}$ with respect to the F/O ratio. The surface morphology was changed to porous and oxide chusters were grown after oxidation $1000^{\circ}C$ for 50 hours by the aggressive evolution of gas phase ($CrO_3$ and$CO_2$). The oxide cluster was composed of Ni and Cr.

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Design of Turbulent In-situ Mixing Mixer and Fabrication of Cu-TiB2 Nanocomposities (난류 용탕 In-situ 합성 믹서의 설계 및 Cu-TiB2 나노 복합재료의 제조)

  • Choi, Baek-Boo;Park, Jung-Su;Yun, Ji-Hun;Ha, Man-Young;Park, Yong-Ho;Park, Ik-Min
    • Korean Journal of Materials Research
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    • v.17 no.1
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    • pp.11-17
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    • 2007
  • Turbulent in-situ mixing process is a new material process technology to get dispersed phase in nanometer size by controlling reaction of liquid/solid, liquid/gas, flow ana solidification speed simultaneously. In this study, mixing which is the key technology to this synthesis method was studied by computational fluid dynamics. For the simulation of mixing of liquid metal, static mixers investigated. Two inlets for different liquid metal meet ana merge like 'Y' shape tube having various shapes and radios of curve. The performance of mixer was evaluated with quantitative analysis with coefficient of variance of mass fraction. Also, detailed plots of intersection were presented to understand effect of mixer shape on mixing. The simulations show that the Reynolds number (Re) is the important factor to mixing and dispersion of $TiB_2$ particles. Mixer was designed according to the simulation, and $Cu-TiB_2$ nano composites were evaluated. $TiB_2$ nano particles were uniformly dispersed when Re was 1000, and cluster formation and reduction in volume fraction of $TiB_2$ were found at higher Re.

Biochemical Characteristics and Function of a Fucosyltransferase Encoded by ste7 in Ebosin Biosynthesis of Streptomyces sp. 139

  • Chang, Ming;Bai, Li-Ping;Shan, Jung-Jie;Jiang, Rong;Zhang, Yang;Guo, Lian-Hong;Zhang, Ren;Li, Yuan
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1092-1097
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    • 2009
  • A novel exopolysaccharide named Ebosin was produced by Streptomyces sp. 139, with medicinal activity. Its biosynthesis gene cluster (ste) has been previously identified. For the functional study of the ste7 gene in Ebosin biosynthesis, it was disrupted with a double crossover via homologous recombination. The monosaccharide composition of EPS-7m produced by the mutant strain Streptomyces sp. 139 ($ste7^-$) was found altered from that of Ebosin, with fucose decreasing remarkably. For biochemical characterization of Ste7, the ste7 gene was cloned and expressed in Escherichia coli BL21. With a continuous coupled spectrophotometric assay, Ste7 was demonstrated to have the ability of catalyzing the transfer of fucose specifically from GDP-$\beta$-L-fucose to a fucose acceptor, the lipid carrier located in the cytoplasmic membrane of Streptomyces sp. 139 ($ste7^-$). Therefore, the ste7 gene has been identified to code for a fucosyltransferase, which plays an essential role in the formation of repeating sugars units during Ebosin biosynthesis.

A Study on the Location and the Types of Enterprise in Ochang Technopolis in Chungcheongbuk-do(Province), Korea (충북지역 오창과학단지의 입지와 기업유형)

  • Jeon, Dong Ho;Joo, Kyung Sik
    • Journal of the Korean association of regional geographers
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    • v.18 no.4
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    • pp.400-413
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    • 2012
  • The purpose of this study was to look into the formation process and characteristics of local high-tech industrial complex with an example of the Ochang Scientific Industrial Complex and analyzed the characteristics by business type and size, transfer process of the companies in the Complex. For this purpose, statistical data of the companies were analyzed and a survey of them was conducted, and the following results were obtained. First, the Ochang Scientific Industrial Complex was created for agglomeration of IT industries in early days but now there are IT industries and BT industries mixed due to internal and external economic condition. Second, there are more small and medium companies than large companies in the Ochang Scientific Industrial Complex. These companies are in the stage of developing new products and marketing, and many of them were parts and materials developers of core technology or high innovation with venture identification. Third, high rates of the companies in the Ochang Scientific Industrial Complex came from the capital area and the Chungcheong area and the companies which moved in the Complex with their head quarters accounted for more than 70 percent. Fourth, the companies were classified into 5 types according to the type of product and the level of technical innovation.

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Structure of Shelf Front and Distribution of Plankotns in the Eastern Part of the Yellow Sea (황해동부의 대륙붕전선의 구조와 부유생물의 분포)

  • CHO Kyu Dae;HONG Seong Yoon;KIM Hee Joon;YANG Yong-Rhim
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.316-329
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    • 1983
  • The formation and structure of the shelf front in the eastern part of the Yellow Sea are studied on the basis of oceanographic data collected in August, 1982 and February, 1983. This paper also describes the distribution of planktonic organisms of the shelf front. In summer the shelf front is formed in the area ($126^{\circ}02^'E-126^{\circ}05^'E$) ca. 20 miles from the shore at the depths of 15-25 m. in winter, however, no distinct shelf front is formed. Based on the cluster analysis of surface phytoplankton the species composition shaws a discontinuous pattern in the vicinity of the shelf front in summer, 1982. A similar trend is observed in distribution of some copepod species in winter, l983.

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