• 분석과학
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• 제8권4호
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• pp.895-900
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• 1995

Urinary free and acetylated polyamine profiles have been investigated for their potential usefulness as biochemical markers of cancer in a control of group comprised of healthy volunteers (32 cases) and patients with various types of cancers(48 cases). The nine (5 free and 4 acetylated) endogeneous polyamines were simultaneously determined by a sensitive capillary gas chromatography/nitrogen-phosphorus detector (GC/NPD). The newly modified (simple and convenient) method was developed and the compounds were isolated by adsorption onto silica gel and derivatized by heptafluorobutyric anhydride to enhance their specificity on gas chromatograms. The good quality-control data were obtained through the precision and accuracy test and the recovery range of them was 48.6 ~ 101.2 %. The Korean reference values of urinary polyamines were established and significant differences were found in cancer patients compared with normal subjects. Also, to eliminate subject variations, precursors to product concentration ratios were compared between cancer patients and control group. The ratios of both putrescine to spermidine and total (free plus acetylated) putrescine to total spermidine were significantly greater in cancer patients than in normal subjects.

• 약학회지
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• 제36권1호
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• pp.26-36
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• 1992

The metabolic profile of triprolidine, 2-[1-(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined in rat urine and bile. The free fractions of urinary and biliary extracts were obtained without hydrolysis, and the conjugated fractions of extracts were obtained with enzyme hydrolysis using ${\beta}-glucuronidase$ from Escherichia coli. The mixture of N-methyl-N-trimethylsilyltrifluoroacetamide/trimethylsilyl chloride (100 : 1, v/v) was used to derivatize the extracts and then analyzed by gas chromatography/mass spectrometry. Hydroxymethyltriprolidine, hydroxytriprolidine, triprolidine carboxylic acid, dihydroxytriprolidine 1, dihydroxytriprolidine 2, oxotriprolidine carboxylic acid and unchanged triprolidine were detected in rat urine and bile, which were obtained after oral treatment with triprolidine hydrochloride. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from free fraction was at 1 to 2 hours after drug administration. Hydroxymethyltriprolidine was detected in conjugated fraction, and the maximum urinary excretion rate of that metabolite was at 2 to 3 hours in rat. In rat bile analysis, triprolidine was detected only in free fraction and its biliary excretion rate showed the maximum within 30 minutes after drug administration and decreased continuously thereafter. The excretion percentage of triprolidine and hydroxymethyltriprolidine to the initial dose of the parent drug in bile and urine of rats were all low.

• Journal of Electrochemical Science and Technology
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• 제6권4호
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• pp.116-120
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• 2015

Lithium diffusivity of fluorine-free and -doped tin-nickel (Sn-Ni) film model electrodes with improved interfacial (solid electrolyte interphase (SEI)) stability has been determined, utilizing variable rate cyclic voltammetry (CV). The method for interfacial stabilization comprises fluorine-doping on the electrode together with the use of electrolyte including fluorinated ethylene carbonate (FEC) solvent and trimethyl phosphite additive. It is found that lithium diffusivity of Sn is largely dependent on the fluorine-doping on the Sn-Ni electrode and interfacial stability. Lithium diffusivity of fluorine-doped electrode is one order higher than that of fluorine-free electrode, which is ascribed to the enhanced electrical conductivity and interfacial stabilization effect.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.209-209
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• 2012

High-efficient transparent conductive oxide (TCO) film-embedding Si heterojunction solar cells were fabricated. An additional doping was not applied for heterojunction solar cells due to the spontaneous junction formation between TCO films and an n-type Si substrate. Three different TCO coatings were formed by sputtering method for an Al-doped ZnO (AZO) film, an indium-tin-oxide (ITO) film and double stacks of ITO/AZO films. An improved crystalline ITO film was grown on an AZO template upon hetero-epitaxial growth. This double TCO films-embedding Si heterojunction solar cell provided significantly enhanced efficiency of 9.23% as compared to the single TCO/Si devices. The effective arrangement of TCO films (ITO/AZO) provides benefits of a lower front contact resistance and a smaller band offset to Si leading enhanced photovoltaic performances. This demonstrates a potential scheme of the effective TCO film-embedding heterojunction Si solar cells.

• 한국세라믹학회지
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• 제49권1호
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• pp.43-47
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• 2012

Electromigration in molten $Ge_2Sb_2Te_5$ (GST) was characterized using pulsed DC stress to an isolated line structure. When an electrical pulse was applied to the GST, GST lines were melted by Joule heating, and Ge and Sb atoms migrate to the cathode, whereas Te atoms migrate to the anode. This elemental separation in the molten GST was caused by an electrostatic force-induced electromigration. The effects of O-, N-, and Bi-doping on the electromigration were also investigated, and atomic mobility changes by the doping were investigated by quantifying $DZ^*$ values. The Bi -doping did not affect the $DZ^*$ values of the constituent atoms in the molten GST, but the D$DZ^*$ values decreased by O-doping and N-doping.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.81-81
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• 1995

It is well known that Src Homology 2(SH2) domain in many intracellular signal transduction proteins is very important. The domain has about 100 amino acid residues and bind phosphotyrosine-containing peptide with high affinity and specificity. Lck SH2 domain is a Src-like, lymphocyte-specific tyrosine kinase. An 11-residue phosphopeptide derived from the hamster polvoma middle-T antigen, EPQp YEEIPIYL, binds with an 1 nM dissociation constant to Lck SH2 domain. And it is known that the phosphotyrosine and isoleucine residues of the peptide are tightly bound by two well-defined pockets on Lck SH2 domain's surface. To investigate the conformational changes during complexation of SH2 domain with phosphopeptide we have performed the molecular dynamics simulation for Lck SH2 domain with peptide and peptide-free form at look in aqueous solution. More than 3000 water molecules were incorporated to solvate Lck SH2 domain and peptide. Periodic boundary condition has been applied in molecular dynamics simulation. Data analysis with the results of that simulation shows that the phosphopeptide makes primary interaction with the Lck SH2 domain at six central residues, The comparison of the complexed and uncomplexed SH2 domain structures in solution has revealed only relatively small change. But the hydrophilic and hydrophobic pockets in the protein surface show the conformational changes in spite of the small structural difference between the complex and peptide-free forms.

• 분석과학
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• 제8권3호
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• pp.229-236
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• 1995

생체시료에 존재하는 유리 아미노산의 분석을 위하여 pH 7.2의 완충용액 조건하에서 Amino Quant $C_{18}$ 컬럼에 diode array detector(DAD) 검출기가 부착된 HPLC에 의한 다단계 기울기 용리법이 사용되었다. 한국인 정신분열증 환자와 정상 한국인의 혈장시료내의 유리 아미노산은 3-mercaptopropionic acid 존재하에서 o-phthalaldehyde와 유도체 반응을 시켰다. 내부표준법에 의한 생체시료에서의 아미노산의 정량분석은 상대표준편차가 2~6%로서 재현성 있는 결과를 보여 주었다. 또한 한국인의 생체시료 중 아미노산의 함량은 외국인의 것과는 다른 결과를 얻었으며 정상인과 비정상인의 평균 tyrosine량은 큰 차이가 있었다.

• Mass Spectrometry Letters
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• 제9권1호
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• pp.30-36
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• 2018

A quantitation method for free amino acids in human serum was developed using a stepwise-dilution method and a bimodal cation exchange (CEX)/hydrophilic interaction liquid chromatography (HILIC)-tandem mass spectrometry system equipped with an electrospray ionization source (ESI/MS/MS). This method, which was validated using quality control samples, was optimized for enhanced selectivity and sensitivity. Dithiothreitol (DTT) was used as a reducing agent to prevent the oxidation of a serum sample ($50{\mu}L$), which was then subjected to stepwise dilution using 3, 30, and 90 volumes of acetonitrile containing 0.1% formic acid. Chromatographic separation was performed on an Imtakt Intrada Amino Acid column ($50mm{\times}3mm$, $3{\mu}m$) in mixed mode packed with CEX and HILIC ligands embedded in the stationary phase. Underivatized free amino acids were eluted and separated within 10 min. As a result of the validation, the precision and accuracy for the inter- and intraday assays were determined as 2.11-11.51% and 92.82-109.40%, respectively. The lowest limit of quantification (LLOQ) was $0.5-4.0{\mu}g/mL$ and the matrix effect was 80.22-115.93%. The proposed method was successfully applied to the quantitative analysis of free amino acids in human serum.

• 분석과학
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• 제15권5호
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• pp.482-487
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• 2002

Carteolol은 국제올림픽위원회 (IOC)에서 금지약물로 규정하고 있는 ${\beta}$-차단제 중의 하나이다. 본 실험에서는 GC/MS를 사용하여 사람의 소변으로부터 carteolol의 복용여부를 확인하기 위한 검출방법 및 대사와 배설에 대해서 고찰하였다. 이를 위하여 효소 가수분해방법과 산 가수분해방법을 비교하여 보았는데 효소가수분해방법이 더 좋은 결과를 얻을 수 있었다. 효소 가수분해방법을 이용하여 실험한 결과 RSD 10%내외의 정밀도와 $0.05{\mu}g/m{\ell}$를 제외하고는 오차 5%이내의 좋은 정확도를 보여주었으며 회수율은 78.5%로 나타났다. Carteolol은 소변에서 대부분이 free carteolol과 conjugated carteolol로 존재하며 소량의 p-OH-carteolol로 대사됨을 알 수 있었으며 모 약물로 배출되는 양 중 conjugated form이 59.4%로 나타났다. 소변으로 배출된 carteolol의 양을 측정한 결과 복용양의 49%가 복용 후 72시간까지 모 약물로 배출됨을 알 수 있었다.

• 한국체육학회지인문사회과학편
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• 제55권2호
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• pp.11-22
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• 2016

루만의 체계이론에 입각해서 기존의 반-도핑 커뮤니케이션을 분석한 결과 다음과 같은 결론에 도달하였다. 기존의 반-도핑 커뮤니케이션은 도핑의 원인과 책임을 개인에게 귀속시키는 개인화 전략을 구사하고 있다. 따라서 문제 해결 방법도 적발, 처벌, 교육을 통한 계몽 같이 철저하게 선수나 지도자 같은 개인에게 초점을 맞추고 있다. 이와 같은 전략은 스포츠체계와 그 주변 체계들의 이해관계가 거미줄처럼 복잡하게 얽혀져 생겨나는 도핑현상을 개인의 자유의지에 따른 결정의 결과로 단순화시킬 뿐만 아니라, 스포츠 및 주변체계들의 성찰 기회를 차단함으로써 체계 내부의 구조적 문제를 은폐시키는데 기여하고, 선수나 트레이너 같은 개별 행위자에게 받아들여지기 어려운 무리한 요구를 부과함으로써 도핑방지노력이 실효를 거둘 수 없게 만든다. 도핑 퇴치 노력이 효력을 발휘하기 위해서는 주체 중심 차원을 넘어서 스포츠조직과 사회적 기능체계들의 차원에서 전략을 구상하고 실행해야 한다.