• 한국의학물리학회지:의학물리
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• 제29권1호
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• pp.29-41
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• 2018

The objective of this study was to evaluate the chemical exchange saturation transfer (CEST) effect of amino acids and neurotransmitters, which exist in the human brain, depending on the concentration, pH, and amplitude of the saturation radiofrequency field. Phantoms were developed with asparagine (Asn), ${\gamma}-aminobutyric$ acid (GABA), glutamate (Glu), glycine (Gly), and myoinositol (MI). Each chemical had three different concentrations of 10, 30, and 50 mM and three different pH values of 5.6, 6.2, and 7.4. Full Z-spectrum CEST images for each phantom were acquired with a continuous-wave radiofrequency (RF) saturation pulse with two different $B_1$ amplitudes of $2{\mu}T$ and $4{\mu}T$ using an animal 9.4T MRI system. A voxel-based CEST asymmetry was mapped to evaluate exchangeable protons based on amide (-NH), amine ($-NH_2$), and hydroxyl (-OH) groups for the five target molecules. For all target molecules, the CEST effect was increased with increasing concentration and B1 amplitude; however, the CEST effect with varying pH displayed a different trend depending on the characteristics of the molecule. On CEST asymmetric maps, Glu and MI were well visualized around 3.0 and 0.9 ppm, respectively, and were well separated macroscopically at a pH of 7.4. The exchange rates of Asn, Glu, BABA, and Gly usually decreased with increasing pH. The CEST effect was dependent on the concentration, acidity of the target molecules, and B1 amplitude of the saturation RF pulse. The CEST effect for Asn can be observed in a 9.4T MRI system. The results of this study are based on applying the CEST technique in patients with neurodegenerative diseases when proteins in the brain are increased with disease progression.

• 천문학회지
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• 제51권3호
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• pp.49-63
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• 2018

We carry out a study of Sub-Millimeter Galaxies (SMGs) in the AKARI NEP-Deep field using the James Clerk Maxwell Telescope (JCMT) SCUBA-2 $850{\mu}m$ source catalog, released as part of the SCUBA-2 Cosmology Legacy Survey (S2CLS) program. The SCUBA-2 $850{\mu}m$ map has a root mean square (rms) noise of $1.2mJy\;beam^{-1}$ and covers an area of $0.60degree^2$. We find four SMGs which have counterparts to Herschel sources with spectroscopic redshifts in the literature. In addition, three dust obscured galaxies (DOGs) detected in Herschel bands are selected as a comparison sample. We derive IR luminosities of SMGs using the CIGALE code, which are similar to those of high redshift SMGs from previous studies. The contribution of AGN to the total IR luminosity in SMGs (2%-11%) is smaller than the lower limit for the one in DOGs (19%-35%), which is consistent with the expectation from the evolutionary scenario of massive galaxies. We search for SMGs in overdense regions as protocluster candidates and investigate four regions, including candidates around three DOGs. Finally, we argue that follow-up spectroscopic observation for the NEP-Deep field will provide crucial information to understand the role of SMGs in the evolution of massive galaxies.

• Journal of Astronomy and Space Sciences
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• 제22권4호
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• pp.473-482
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• 2005

대형 적외선 우주 망원경 개발은 한극천문연구원의 중요 전략 목표의 하나로써 이를 성공시키기 위한 다양한 기술적 노력들이 전개되고 있다. 그 일환으로 한국천문연구원과 한국기초과학지원연구원은 정책 협동 과제로 한국기계연구원, (주) 아이쓰리시스템과 함께 우주용 적외선 냉각시스템을 개발하고 있다. 본 논문에서는 이렇게 개발중인 우주탑재용 적외선카메라 냉각시스템 시험모델의 광학계를 설계하기 위한 요구 조건을 도출하였으며, 그에 따라 $3.8\~4.8{\mu}m$ 적외선 대역에서 $15^{\circ}\times12^{\circ}$의 시야를 가지며 각분해능이 $0.047^{\circ}$인 단일 렌즈 카메라 시스템을 설계하였고, 앞으로 더 복잡한 광학계에 대한 기초로 활용하고자 한다.

• 한국식품조리과학회지
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• 제28권3호
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• pp.275-283
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• 2012

본 실험은 반응표면분석법을 이용하여 야관문 에탄올 추출물의 기능성분에 대한 추출조건을 최적화하였다. 추출조건에 따른 수율의 최대값은 17.6%이었고, 중심합성계획에 의한 야관문의 추출조건별 총 폴리페놀 및 총플라보노이드 함량에 대한 반응표면 회귀식의 $R^2$는 각각 0.8562와 0.9787로 10% 및 1%이내의 유의수준에서 유의성이 인정되었다. 야관문 에탄올 추출물의 폴리페놀 및 플라보노이드 함량 변화는 추출온도와 추출시간보다는 에탄올 농도에 크게 영향을 받고 있는 것으로 나타났다. 전자공여능에 대한 회귀식의 $R^2$는 0.8344로 10% 이내의 유의수준에서 유의성이 인정되었다. pH 조건에 따른 야관문의 아질산염 소거능에서 최대점을 보인 pH 3.0에서는 추출온도가 증가할수록 에탄올 농도 범위가 40~60% 범위에서 우수함을 확인하였다. ORAC은 1,636.47~2,696.99 ${\mu}moles$ TE/g의 범위였으며, 결과에 대한 반응표면 회귀식의 $R^2$는 0.8383로 10%이내의 유의수준에서 인정되었고 추출온도보다는 추출시간과 에탄올 농도에 영향을 받는 것으로 나타났다. 야관문의 추출조건을 최적화하기 위하여 추출물의 특성인 조건별 추출물의 수율, 총 폴리페놀함량, 전자공여능, 아질산염 소거능 및 ORAC에 대해 contour map을 superimposing하여 얻은 최적조건의 범위는 추출온도 $78{\sim}85^{\circ}C$, 추출시간 6~7시간, 에탄올 농도 38~60%이었다.

• Applied Biological Chemistry
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• 제49권3호
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• pp.215-220
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• 2006

반응표면분석법을 이용하여 상황버섯의 열수추출을 위한 최적조건을 결정하였다. 추출특성을 조사하기 위하여 추출시간 ($1{\sim}5$시간) 및 가수량$(0.02{\sim}0.10%(W/V))$을 중심으로 10개 종속변수 구간을 설정하여 갈색도, 환원당 및 총당 함량 등을 반응표면분석법으로 모니터링하였다. 그 결과 갈색도$(Y_1)$, 환원당 $(Y_2)$ 및 총당 함량$(Y_3)$은 10% 내에서 유의성이 인정되었고, 갈색도, 환원당 및 총당 함량은 추출시간보다 가수량에 의해 영향을 더 많이 받는 것으로 나타났다. 이상의 결과를 이용하여 contour map을 superimposing 하여 추출물의 특성을 모두 만족시켜주는 최적추출 조건의 범위를 결정한 결과 추출시간은 $3.0{\sim}4.5$시간, 가수량은 상황버섯 1 g 당 $40.0{\sim}58.2\;ml$이었다. 최적 추출조건에서의 상황추출물의 품질특성은 무기원소는 N, K가 다른 무기원소보다 많은 경향을 보였고, 유리당은 sucrose와 glucose가 각각 0.126, 0.012% 존재하는 것으로 확인되었다. 유리아미노산은 총함량이 $503.26\;{\mu}g%$이었으며, 이 중에서 필수아미노산은 유리아미노산 전체의 5.4%를 차지하였다. 또한 다당류의 분자량은 10 KDa 부근의 분자량이 main peak를 이루고 있었다.

• 천문학논총
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• 제27권4호
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• pp.117-122
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• 2012

The interstellar dust grains are formed and supplied to interstellar space from asymptotic giant branch (AGB) stars or supernova remnants, and become constituents of the star- and planet-formation processes that lead to the next generation of stars. Both a qualitative, and a compositional study of this cycle are essential to understanding the origin of the pre-solar grains, the missing sources of the interstellar material, and the chemical evolution of our Galaxy. The AKARI/MIR all-sky survey was performed with two mid-infrared photometric bands centered at 9 and $18{\mu}m$. These data have advantages in detecting carbonaceous and silicate circumstellar dust of AGB stars, and the interstellar polycyclic aromatic hydrocarbons separately from large grains of amorphous silicate. By using the AKARI/MIR All-Sky point source catalogue, we surveyed C-rich and O-rich AGB stars in our Galaxy, which are the dominant suppliers of carbonaceous and silicate grains, respectively. The C-rich stars are uniformly distributed across the Galactic disk, whereas O-rich stars are concentrated toward the Galactic center, following the metallicity gradient of the interstellar medium, and are presumably affected by the environment of their birth place. We will compare the distributions of the dust suppliers with the distributions of the interstellar grains themselves by using the AKARI/MIR All-Sky diffuse maps. To enable discussions on the faint diffuse interstellar radiation, we are developing an accurate AKARI/MIR All-Sky diffuse map by correcting artifacts such as the ionising radiation effects, scattered light from the moon, and stray light from bright sources.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.141-149
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• 2015

"G protein-coupled receptor 40" (GPR40), a receptor for long-chain fatty acids, mediates the stimulation of glucose-induced insulin secretion. We examined the profiles of differential gene expression in GPR40-activated cells treated with linoleic acid, and finally predicted the integral pathways of the cellular mechanism of GPR40-mediated insulinotropic effects. After constructing a GPR40-overexpressing stable cell line (RIN-40) from the rat pancreatic ${\beta}$-cell line RIN-5f, we determined the gene expression profiles of RIN-5f and RIN-40. In total, 1004 genes, the expression of which was altered at least twofold, were selected in RIN-5f versus RIN-40. Moreover, the differential genetic profiles were investigated in RIN-40 cells treated with $30{\mu}M$ linoleic acid, which resulted in selection of 93 genes in RIN-40 versus RIN-40 treated with linoleic acid. Based on the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG, http://www.genome.jp/kegg/), sets of genes induced differentially by treatment with linoleic acid in RIN-40 cells were found to be related to mitogen-activated protein (MAP) kinase- and neuroactive ligand-receptor interaction pathways. A gene ontology (GO) study revealed that more than 30% of the genes were associated with signal transduction and cell proliferation. Thus, this study elucidated a gene expression pattern relevant to the signal pathways that are regulated by GPR40 activation during the acute period. Together, these findings increase our mechanistic understanding of endogenous molecules associated with GPR40 function, and provide information useful for identification of a target for the management of type 2 diabetes mellitus.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.929-934
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• 2001

The physiological role of brain somatostatin in the central regulation of feed intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of somatostastin 1-28 (SRIF) at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCI solution were given ad libitum. Feed, water and salt intake were measured during ICV infusion of artificial cerebrospinal fluid (CSF) and SRIF. The feed intake during SRIF infusion on days 2 to 5 increased significantly compared to that during CSF infusion. Water intake, when compared to that during CSF infusion, only increased significantly on day 4. NaCI intake during SRIF infusion was not different from that during CSF infusion. Mean arterial blood pressure (MAP) and heart rate during SRIF infusion were not different from those during CSF infusion. The plasma concentrations of Na, K, Cl, osmolality and total protein during SRIF infusion were also not different from those values during CSF infusion.There are two possible mechanisms, that is, the suppression of brain SRIF on feed suppressing hormones and the direct actions on brain mechanisms controlling feed intake, explaining how SRIF works in the brain to bring about increases in feed intake in sheep fed on hay. The results indicate that brain SRIF increases feed intake in sheep fed on hay.

• 대한본초학회지
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• 제26권2호
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• pp.17-23
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• 2011

Objectives : This study aims at examining the effect of the fermentative extract of root of Sophorae Radix on the immuno-modulating activity. Methods : Cell viabilities were measured by MTT assay. Effect of SFS on nitric oxide(NO), hydrogen peroxide production from RAW 264.7 cells was accessed by Griess reagent assay. Effect of SFS on productions of inflammatory cytokines such as TNF-${\alpha}$, IL-6 in LPS-induced RAW 264.7 cells was accessed by a multiplex bead array assay based on xMAP technology. Results : The results of the experiment are as follows. 1. As a result of carrying out MTT assay to check the cellular toxicity of the fermentative extract of Sophorae Radix. There was not any excessive toxicity to the macrophage when the fermentative extract of root of Sophorae Radix was treated in different concentrations. 2. The fermentative extract of Sophorae Radix increased the generation of hydrogen peroxide in the macrophage and significantly restored the suppression of the generation of the hydrogen peroxide in the macrophage induced by LPS. 3. The fermentative extract of Sophorae Radix reduced the generation of NO in the macrophage and significantly suppressed the increase of the generation of NO in the macrophage induced by LPS. 4. The fermentative extract of Sophorae Radix significantly decreased the amount of TNF-${\alpha}$ generated in the macrophage induced by LPS when it was $25{\mu}g/mL$ or higher. Conclusion : These results suggest that SFS has anti-inflammatory moiety related with its inhibition of NO, hydrogen peroxide, TNF-${\alpha}$, IL-6, in macrophage led by LPS.

• 동의생리병리학회지
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• 제27권6호
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• pp.795-801
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• 2013

The purpose of this study is to investigate effects of White Ginseng-Ejung-tang (EG) and Red Ginseng-Ejung-tang (ER) water extract on production of various cytokines such as interleukin (IL)-21, IL-25, IL-$28{\beta}$, erythropoietin (EPO), Exodus-2, monocyte chemotactic protein (MCP)-5, macrophage inflammatory protein (MIP)-$3{\alpha}$, MIP-$3{\beta}$, Fractalkine, and TARC in RAW 264.7 mouse macrophages stimulated by lipopolysaccharide (LPS). Levels of cytokines were measured by High-throughput multiplex bead array cytokine assay based on xMAP (multi-analyte profiling beads) technology. ER significantly decreased levels of IL-21, IL-25, IL-$28{\beta}$, EPO, Exodus-2, MCP-5, MIP-$3{\alpha}$, MIP-$3{\beta}$, TARC, and fractalkine for 24 h incubation at the oncentrations of 25 and 100 ${\mu}g/mL$ in LPS-induced RAW 264.7 (P < 0.05). But EG did not show any significant effect. These results suggest that ER has anti-inflammtory property related with its inhibition on the production of IL-21, IL-25, IL-$28{\beta}$, and chemokines such as EPO, MCP-5, MIP-$3{\alpha}$, MIP-$3{\beta}$, Fractalkine, Exodus-2, and TARC in LPS-induced macrophages.