• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.225-231
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• 1997

As it has been reported that the depolarization-induced norepinephrine (NE) release is modulated by activation of presynaptic $A_1-adenosine$ heteroreceptor and various lines of evidence indicate the involvement of adenylate cyclase system in $A_1-adenosine$ post-receptor mechanism in hippocampus, it was attempted to delineate the role of adenylate cyclase system in the $A_1-receptor-mediated$ control of NE release in this study. Slices from rat hippocampus were equilibrated with $[^3H]-NE$ and the release of the labelled products was evoked by electrical stimulation.(3 Hz, $5Vcm^{-1}$, 2 ms, rectangular pulses). The influence of various agents on the evoked tritium-outflow was investigated. $N^6-Cyclopentyladenosine$ (CPA), a specific $A_1-adenosine$ receptor agonist, in concentrations Tanging from 0.1 to $10{\mu}M$ decreased the $[^3H]-NE$ release in a dose-dependent mauler without any change of basal rate of release. 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX, $2{\mu}M$), a selective $A_1-receptor$ antagonist, inhibited the CPA effect. The responses to N-ethylmaleimide $(3&10{\mu}M)$, a SH-alkylating agent of G-protein, were characterized by increments of the evoked NE-release and the CPA effects were completely abolished by NEM pretreatment. Forskolin, a specific adenylate cyclase activator, in concentrations ranging from 0.1 to $30{\mu}M$ increased the evoked and basal rate of NE release in a dose-dependent manner and the CPA effects were inhibited by forskolin pretreatment. Rolipram $(1&10{\mu}M)$, a phosphodiesterase inhibitor, did not affect the evoked NE release but reduced the CPA effect. And 8-bromo-cAMP $(100&300{\mu}M)$, a membrane permeable cAMP analogue inhibited the CPA effect significantly. These results suggest that the $A_1-adenosine$ heteroreceptor plays an important role in NE-release via nucleotide-binding protein $G_i$ in the rat hippocampus and that the adenylate cyclase system might be participated in this process.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.357-360
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• 2016

Chrysanthemum morifolium flowers were extracted with 80 % aqueous MeOH, and the concentrated extract was partitioned into EtOAc, n-butyl alcohol (n-BuOH), and water fractions. The repeated silica gel and octadecyl silica gel column chromatographies for the EtOAc and n-BuOH fractions led to isolation of four flavonoids. The chemical structures of the compounds were determined as acacetin (1), apigenin (2), apigenin-7-O-${\beta}$-$\small{D}$-glucopyanoside (3), acacetin-7-O-${\beta}$-$\small{D}$-glucopyranoside (4) based on spectroscopic data analyses including nuclear magnetic resonance, mass spectrometry, and infrared spectrometry.

• KSBB Journal
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• v.21 no.2
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• pp.133-139
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• 2006

In 'solid-phase' PEGylation, the conjugation reaction occurs as the proteins are attached to a solid matrix, and thus it can have distinct advantages over the conventional, solution-phase process. We report a case study: rhIFN-${\alpha}$-2a was first adsorbed to cation exchange resin and then N-terminally PEGylated by aldehyde mPEG of 5, 10, and 20 kD through reductive alkylation. After the PEGylation, salt gradient elution efficiently recovered the mono-PEGylate in a purified form from the unwanted species such as unmodified IFN, unreacted PEG, and others. The mono-PEGylation and its purification were integrated in a single chromatographic step. Depending on the molecular weight of the mPEG aldehyde used, the mono-PEGylation yield ranged 50-64%. We could overcome the major problems of random, or uncontrollable, multi-PEGylation and the post-PEGylation purification difficulties associated with the solution-phase process. N-terminal sequencing and MALDI-TOF MS confirmed that a PEG molecule was conjugated only to the N-terminus. Compared with the unmodified IFN, the mono-PEGylate showed the reduced anti-viral activity as measured by the cell proliferation assay. The bioactivity was reduced more as the higher molecular weight PEG was conjugated. Immunoreactivity, evaluated indirectly by antibody binding activity using a surface plasmon resonance biosensor, also decreased. Nevertheless, trypsin resistance as well as thermal stability was considerably improved.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2006.06a
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• pp.46-66
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• 2006

새로운 지능기반사회(ubiquitous society) 패러다임이란 전제 아래 미국을 비롯해 일본, 유럽 등 세계 각국에서는 모바일, 브로드밴드, 극소형 컴퓨터, IPv6의 기술이 창출해 내는 컴퓨팅 혁명의 실체를 유비궈터스 IT로 파악하고 각 국의 걸부, 기업, 연구소들이 주도권을 잡기 위해 많은 노력을 기울이고 있다. 현재 유비쿼터스 IT를 활용한 u-비즈니스를 활성화하고 관련 시장을 선점하기 위한 전 세계적인 경쟁은 매우 치열한 양상을 보이고 있다. 주요 국가들은 서로 지향하는 영역은 다르지만 궁극적으로 지능기반사회 구현이라는 대명제 아래 독자적인 산업 구축을 위해 노력하고 있다. 이러한 이유는 기본적으로 지능기반사회로의 이행과정에서 발생하는 경제적 파급효과, 예컨대 디지털 가전, 이동통신기기, 전자의료기기, 디스플레이, 2차 전지, 보안 등 관련 산업에 미치는 영향 및 새로운 시장 창출의 기회가 있기 때문이다. 기존의 많은 연구 및 문헌에서는 아직도 유비쿼터스 IT에 대한 개념적인 논의에 치중되어 있고 시장 중심적 또는 수요자 중심적 사고의 논의가 부족하다. 성공적으로 유비쿼터스 산업을 육성하기 위해서는 유비쿼터스 IT자체기술 개발사업(tangible service) 뿐만 아니라 비가시적(intangible) 서비스, 그리고 컨버전스(convergence) 서비스에 대한 상용화 모델과 성공적 사업 전개 방법론에 대한 깊은 연구가 수행되어야 한다. 본 연구에서는 먼저 유비쿼터스 IT의 기술동향과 시장 동향 및 산업 규모에 대한 문헌연구를 통해 u-비즈니스의 가능성을 고찰해보고, u-비즈니스 추진 전략을 탐색적으로 제시하고자 한다.되었다. SPME-GC/MS에 의한 휘발성분 분석 결과, 기능성 유지에서 홍국쌀 에탄올 추출물로부터 기인되는 특유의 휘발성분은 관찰되지 않았으나, RT=12.1 min인 hexanal의 함량이 control에 비하여 유의적인 감소 경향을 나타내는 것이 확인되었다(p<0.05).히지 못하여, 이의 기전을 밝히기 위한 추후 연구가 필요하다./TEX>로서 p<0.01 수준에서 현저히 증가하였다. 혈청의 인지질과 콜레스테롤 에스테르의 지방산 조성에서 vitamin C를 혼합 투여한 3,5,7군에서 PUFA 함량이 증가한 반면, SFA 함량은 감소하여 P/S 비율, n-3P/n-6P 비율은 증가하는 경향이었으며 이는 간장의 인지질, 콜레스테롤 에스테르, 총 지질의 지방산조성에서도 같은 경향을 볼 수 있었다.X>$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 대부분을 차지하였다. 야생 돌복숭아 과육 중의 지방산 조성은 포화지방산이 16.74%, 단불포화지방산 17.51% 및 다불포화지방산이 65.73%의 함유 비율을 보였는데, 이 중 다불포화지방산인 n-6계 linoleic acid$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 지질 구성 총 지방산의 대부분을 차지하는 함유 비율을 나타내었다.했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.235-242
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• 2011

In order to improve forage characteristics of Italian ryegrass by genetic transformation, an efficient callus induction from mature seed and optimal plant regeneration system were established using a domestic cultivar 'Kospeed'. Addition of 5 mg/L of 2,4-D showed highest frequency of embryogenic callus induction from mature seeds. N6 medium showed higher frequency of both callus induction and plant regeneration as compared with MS and SH medium. The highest plant regeneration frequency 67% was obtained when embryogenic calli were transferred to N6 medium containing 1 mg/L 2,4-D and 5 mg/L BA. Supplementation of regeneration medium with sucrose at 30 g/L level maximized regeneration frequency as compared to the other concentrations. These data would be very helpful for molecular breeding of domestic Italian ryegrass cultivar through genetic transformation.

• Analytical Science and Technology
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• v.20 no.4
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• pp.268-278
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• 2007

Nitrite which can be derived from water for dilution of metal working fluid can induce nitroso compounds which can be classified as carcinogen, if it co-exists with ethanolamines added for pH control in metal working fluid. The survey of nitrite, nitrate and nitroso-compounds level in 42 metal-working fluids collected from 17 factories was done by ion chromatography and gas chromatography with mass detector. Diluted metal working fluid showed higher level of nitrite and nitrate compared with raw fluid. Nitrite was detected in 11 (52%) samples among 21 diluted solution. Three (14%) samples showed over German recommendation level ($20{\mu}g/mL$).N-nitrosodiethanolamine(NDELA) was detected in 18 samples among 21 diluted solution. Seven (33%) samples showed over German recommendation level ($5{\mu}g/mL$). The concentration of NDELA was correlated with nitrite ion ($R^2=0.453$, n=19).

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.483-494
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• 1993

Cell surface antigenic relationships between pathogenic mycobacteria have been investigated by the enzyme-linked immunosorbent assay using phenolkilled cells and their rabbits antisera. Homologous and heterologous reactions of Mycobacterium avium-intracellulare antisera before and after homologous and heterologous absorption revealed a close antigenic relationship between strains of the same species and between species if they were members of M. avium(MA)-intracellulare(MI)-scrofulaceum(MG) complex. MAI sera showed a considerable reaction with M. kansasii(MK) and tuberculosis(MTB), but not with the other species. MA(K40004) antiserum reacted with other mycobacteria except few strains of MI and 50~89% of homologous reaction was reduced by heterologous absorption with cells of MI or MS. Intraspecific reaction of MI antisera was natural1y stronger than interspecific reaction and different in extent due to a magnitude of antigenic sharing. Antigenic relationships between N-260D, N-260R, N-260T, and K41014 was somewhat closer than that with N-242D, N-257T, N-28ID, and N-275T. M. nonchromogenicum(MNC) antisera showed a strong interspecific reaction with exception of M. chelonei(MC) and triviale(MTV) to which they reacted weakly or none. Antigenic sharing with M. terrae(MTR) and MG(K30003) was next to intraspecific sharing. NC-3 shared antigens considerably with MA, MC, and M. fortuitum(MF) while NC-11 did not. MTR antisera showed a strong cross-reaction with MI but their homologous reaction was not reduced by MI absorption indicating a paucity of shared antigen of MTR surface. Intraspecific antigenic sharing of course was large with on exception between T-8 and T-13. A considerable amount of antigenic sharing was also found with MNC, MC and MF. Unlike T-8 serum, T-13 antiserum strongly cross-reacted with MA, MG, MK, and MTB. In general, antigenic relationships of mycobacteria, that have been elucidated in this study, well conformed to taxons delineated by the various biological and biochemical means.

• Applied Biological Chemistry
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• v.17 no.3
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• pp.149-176
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• 1974

Eight substituted diphenyl ether herbicides and some of their photoproducts were studied in terms of solution phase photolysis under simulated environmental conditions by using a Rayonet photochemical reactor. The test compounds absorbed sufficient light energy at the wavelength of 300 nm to undergo various photoreactions. All the photoproducts were confirmed by means of tlc, glc, ir, ms, and/or nmr spectrometry. The results obtained are summarized as follows: Solution phase photolysis of C-6989: An exceedingly large amount of p-nitrophenol formed strongly indicates the readiness of the ether linkage cleavage of this compound as the main reaction in all solvents used. Photoreduction of nitro to amino group(s) and photooxidation of trifluoromethyl to carboxyl group were recognized as minor reactions. Aqueous photolysis of p-nitrophenol: Quinone(0.28%), hydroquinone (0.66%), and p-aminophenol (0.42%) were confirmed as photoproducts, in addition to a relatively small amount of an unknown compound. The mechanisms of formation of these products were proposed to be the nitro-nitrite rearrangement via $n{\rightarrow}{\pi}^*$ excitation and the photoreduction through hydrogen abstractions by radicals, respectively. Solution phase photolysis of Nitrofen: Photochemical reduction leading to the p-amino derivative was the main reaction in n-hexane. In aqueous solution, the photoreduction of nitro to amino group and hydroxylation predominated over the ether linkage cleavage. Nucleophilic displacement of the nitro group by hydroxide ion and replacement of chlorine substituents by hydroxyl group or, to a lesser extent, hydrogen were also observed as minor reactoins. Solution phase photolysis of MO-338: Photoreduction of the nitro to amino group was marked in the n-hexane solution photolysis. In the aqueous solution, photoreduction of the nitro substituent and hydroxylation were the main reactions with replacement of chlorine substituents by the hydroxyl group and hydrogen, and cleavage of the ether linkage as minor reactions. Photolyses of MC-4379, MC-3761, MC-5127, MC-6063, and MC-7181 in n-hexane and cyclohexane: Photoreduction of the nitro group leading to the corresponding amino derivative and replacement of one of the halogen substituents by hydrogen from the solvent used were the key reactions in each compound. Aqueous photolysis of MC-4379: Cleavage of the ether linkage, replacement of the carboxymethyl by hydroxyl group, hydroxylation, and replacement of the nitro by hydroxy group were prominent with photoreduction and dechlorination as minor reactions. Aqueous photolysis of MC-3761: Cleavage of the ether linkage, replacement of the carboxymethyl by hydroxyl group, and photoreduction followed by hydroxylation were the main reactions. Aqueous photolysis of MC-5127: Replacement of carboxyethyl by hydrogen was predominant with ether linkage cleavage, photoreduction, and dechlorination as minor reactions. It was obvious that the decarboxyethylation proceeded more readily than decarboxymethylation occurring in the other compounds. Aqueous photolysis of MC-6063: Cleavage of the ether linkage and photodechlorination were the main reactions. Aqueous photolysis of MC-7181: Replacement of the carboxymethyl group by hydrogen and monodechlorination were the remarkable reactions. Cleavage of the ether linkage and hydroxylation were thought to be the minor reactions. Aqueous photolysis of 3-carboxymethyl-4-nitrophenol: The photo-induced Fries rearrangement common to aromatic esters did not appear to occur in the carboxymethyl group of this type of compound. Conversion of nitro to nitroso group was the main reaction.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.781-785
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• 2006

The chemical compositions of the seeds of the safflower (Carthamus tinctorius L.) plant were evaluated to determine possible compound having proliferative effects on human osteoblast cells. Three-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test and alkaline phosphatase (ALP) activity were used to assess the effects of the isolates on the human osteoblast-like line (Saos-2). Activity guided fractionation led to the isolation of ALP activating lignin and alkaloid glycosides through the extraction of the seeds, solvent partitioning and repeated silica gel and octadecyl silica (ODS) column chromatographic separations. The data from Nuclear Magnetic Resonance (NMR), Mass (MS), and Infrared (IR) analyses enabled the determination of the chemical structure and characterization of two compounds as a tracheloside and an N-(p-coumaroyl)-serotonin mono-${\beta}$-D-glucopyranoside. These two compounds showed respectively $149.2{\pm}4.2$ and $138.9{\pm}3.5%$ ALP activity compared to the control when evaluated at a concentration of $100\;{\mu}g/mL$.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.652-660
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• 1993

It was investigated to obtain the relationship between magnetic properties and conditions of forming $Fe_{3}C$ single phase from acicular goethite by heat treatment under the atmosphere of CO and $N_{2}$ mixed gas. X-ray analyses, TEM and VSM measurements were imployed for the characteristics of the carbide. Acicular goethite was sinthesized under proper process parameters. $Fe_{3}C$ single phase was obtained above $550^{\circ}C$, 60min. and $Fe_{5}C_2$ was formed with $Fe_{3}C$ below that temperature. The soturation magnetization of $Fe_{3}C$ single phase was about 100emu/g regardless of the reaction temperature. The coersive force and the ratio of Mr/Ms decreased respectively from 780 to 400 Oe. and from 0.35 to 0.13 with increasing reaction temperature.