• 대한화학회지
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• 제32권3호
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• pp.243-248
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• 1988

수용액에서 몇가지 란탄 착화합물의 hypersensitive 전이대를 연구하였다. 리간드의 염기도$(pK_a)$와 란탄 착화합물의 hypersensitive 전이대의 진동자 세기 사이에 정립된 선형 관계에 근거를 두고, 금속-리간드 결합간에 존재하는 공유 결합성을 anthranilate, pyrazine-2-carboxylate, 및 pyruvate 착화합물에 대해서 논하였다.

• 분석과학
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• 제20권3호
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• pp.246-250
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• 2007

The quantitative determination of chromium(VI) by separation from chromium(III) complex of 8-hydroxyquinoline using solvent extraction has been studied. The reaction conditions for chromium(III) complex of 8-hydroxyquinoline and the solvent extraction of complex were investigated in detail. The chromium(III) complex was extracted with organic solvent (n-hexane) and residual chromium(VI) was determined by ICP-AES in aqueous layer. This technique is quantitative in the pH range of 8-9 and the limitations such as interfering ions were discussed.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3923-3927
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• 2011

A noble method for pre-concentration and speciation of ultra trace As (III) and As (V) in urine and whole blood samples based on dispersive liquid-liquid microextraction (DLLME) has been developed. In this method, As (III) was complexed with ammonium pyrrolidine dithiocarbamate at pH = 4 and Then, As (III) was extracted into the ionic liquid (IL). Finally, As (III) was back-extracted from the IL with hydrochloric acid (HCl) and its concentration was determined by flow injection coupled with hydride generation atomic absorption spectrometry (FI-HGAAS). Total amount of arsenic was determined by reducing As (V) to As (III) with potassium iodide (KI) and ascorbic acid in HCl solution and then, As (V) was calculated by the subtracting the total arsenic and As (III) content. Under the optimum conditions, for 5-15 mL of blood and urine samples, the detection limit ($3{\sigma}$) and linear range were achieved 5 ng $L^{-1}$ and 0.02-10 ${\mu}g\;L^{-1}$, respectively. The method was applied successfully to the speciation and determination of As (III) and As (V) in biological samples of multiple sclerosis patients with suitable precision results (RSD < 5%). Validation of the methodology was performed by the standard reference material (CRM).

• 약학회지
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• 제40권6호
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• pp.670-678
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• 1996

The combinations of N-4-salicyloamido-2-amino-6-piperidinopyrimidine 3-oxide (Salmi) and two transitional metals were colored. Among metals, Fe(III) made a distinct colored comp lex with Salmi. The mole ratio of Salmi and Fe(III) in the complex was 1:1. This Salmi-Fe(III) complex was recrystallized in Hexane/Acetone(=10/1, v/v) and investigated its physicochemical properties. The color of this complex was changed by pH.; deep violet pink in acids, orange in neutral, and yellow in bases. The range of color change was approximately 0.7 pH unit. Acid-base titration of various acidic or basic drugs using Salmi-Fe(III) complex as an indicator showed good accuracy and reproducibility.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권4호
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• pp.397-410
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• 2000

Skeletal class III had been classified by the position of the maxilla, the mandible, the maxillary alveolus, the mandibular alveolus and vertical development. This morphologic approach is simple and useful for clinical use, but it is insufficient to permit understanding of the pathophysiology of dysmorphoses. The author hypothesizes that there are different patterns of mutual relation of the skeletal components which have contributed pathologic equilibrium of skeletal class III. The purpose of this study are threefold: 1) to classify skeletal class III in subgroups, which can show the architectural characteristics of the deformity, 2) to analyse the craniofacial architecture of each subgroup on etio-pathogenic basis, and 3) to characterize and visualize the pattern as a prototype. Materials used in this study were lateral cephalograms of 106 skeletal class III adults, which were analysed with modified Delaire's architectural and structural analysis. Linear and angular measurements of the individual subject were obtained and cluster analysis was used for the subgrouping. Data were evaluated for verification of the statistical significances. The following results were obtained. 1. By the modified Delaire's architectural and structural analysis and cluster analysis, skeletal class III adults were classified into 7 clusters and presented as prototypes, which could show the pathophysiology of the skeletal architecture 2. There was significant relationship in measurement variables of each cluster, which could reflect characteristics of the skeletal pattern of growth. 3. The flexure of cranial base had a close relationship to the anterior rotational growth of the maxilla and contributes to understand the etio-pathology of skeletal class III. 4. The proportion of craniospinal area in cranial depth, craniocervical angle and vertical position of point Om had a close relationship to rotational growth of the mandible and direction of condylar growth. They contribute to understand the etio-pathology of skeletal class III. In summary, the cranium and the craniocervical area must be considered in diagnosis and treatment planning of dentofacial deformity. And the occlusal plane can be considered as a representative which shows the mutual relationships of the skeletal components.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.366-372
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• 2003

The production of microbiologically enriched cultures that degrade cis- 1,2-dichloroethylene(DCE) under anaerobic conditions was investigated. Among 80 environmental samples, 19 displayed significant degradation of $10{\mu}M$ cis-DCE during 1 month of anaerobic incubation, and one sediment sample collected at a landfill area (Nanji-do, Seoul, Korea) showed the greatest degradation ($94\%$). When this sediment culture was subcultured repeatedly, the ability to degrade cis-DCE gradually decreased. However, under Fe(III)-reducing conditions, cis-DCE degradation by the subculture was found to be maintained effectively. In the Fe(III)-reducing subculture, vinyl chloride (VC) was also degraded at the same extent as cis-DCE No accumulation of VC during the cis-DCE degradation was observed. Thus, Fe(III)-reducing microbes might be involved in the anaerobic degradation of the chlorinated ethenes. However, the subcultures established with Fe(III) could function even in the absence of Fe(III), showing that the degradation of cis-DCE and VC was not directly coupled with the Fe(III) reduction. Consequently, the two series of enrichment cultures could not be obtained that degrade both cis-DCE and VC in the presence or absence of Fe(III). Considering the lack of VC accumulation, both cultures reported herein may involve interesting mechanism(s) for the microbial remediation of environments contaminated with chlorinated ethenes. A number of fermentative reducers (microbes) which are known to reduce Fe(III) during their anaerobic growth are potential candidates involved in cir-DCE degradation in the presence and absence of Fe(III).

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.923-928
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• 2000

[FeIII(BBA)DBC]ClO4 as a new functional model for catechol dioxygenases has been synthesized, where BBA is a bis(benzimidazolyl-2-methyl)amine and DBC is a 3,5-di-tert-butylcatecholate dianion.The BBA complex has a structuralfeature that iron cent er has a five-coordinate geometry similar to that of catechol dioxygenase-substrate complex.The BBA complex exhibits strong absorptionbands at 560 and 820 nm in CH3CN which are assigned to catecholate to Fe(III) charge transfer transitions. It also exhibits EPR signals at g = 9.3 and 4.3 which are typical values for the high-spin FeIII (S = 5/2) complex with rhombicsymmetry. Interestingly, the BBA complex reacts with O2 within an hour to afford intradiol cleavage (35%) and extradiol cleavage (60%) products. Surprisingly, a green color intermediate is observed during the oxygenation process of the BBA com-plex in CH3CN. This green intermediate shows a broad isotropic EPR signal at g = 2.0. Based on the variable temperature EPR study, this isotropic signalmight be originated from the [Fe(III)-peroxo-catecholate] species havinglow-spin FeIII center, not from the simple organic radical. Consequently,it allows O2 to bind to iron cen-ter forming the Fe(III)-superoxide species that converts to the Fe(III)-peroxide intermediate. These present data can lead us tosuggest that the oxygen activation mechanism take place for the oxidative cleavingcatechols of the five-coordinate model systems for catechol dioxygenases.

• 대한화학회지
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• 제44권6호
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• pp.541-546
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• 2000

리간드 증감 유발 형광법을 이용하여 Tb(III)-L-dopa (L-3,4-dihydroxyphenyl alanine) 착이온의 방출세기를 측정함으로써 수용액 중의 L-dopa를 정량하는 방법에 대하여 연구하였다. 들뜸파장, pH, 보조 형광증가제의 선택, Tb(III) 이온의 농도, 보조 형광증가제로 사용된 Lu(III) 이온의 농도 및 방출파장의 방출세기에 대한 영향을 조사하였다. 보조 형광증가제로서 Lu(III) 이온을 첨가하였을때 Tb(III) 이온의 방출세기가 현저히 증가함을 관찰하였고, L-dopa의 검출한계를 낮출 수 있었다. 보조 형광증가제를 첨가하지 않았을 경우에 L-dopa 검정곡선의 직선감응범위는 들뜸파장, pH 및 Tb(Ⅲ) 이온의 농도가 각각 300 nm, 8.0 및 $1.0{\times}10^{-4}$ M였을때, $5.0{\times}10^{-7}$ M~$1.0{\times}10^{-4}$ M였다. 이 조건에서의 검출한계는 $4.0{\times}10^{-8}$ M였다. 보조 형광증가제를 첨가하였을 경우에는 들뜸파장, pH, Tb(III) 이온의 농도, 보조 형광증가제로 사용된 Lu(III) 이온의 농도 및 방출파장이 각각 300 nm, 8.5, $1.0{\times}10^{-5}$ M, $1.0{\times}10^{-5}$ M 및 545 nm였을 때, 직선감응범위가 1.0×$10^{-8}$ M~2.0{\times}10^{-4}$ M였고, 이 때의 검출한계는 $1.0{\times}10^{-9}$ M였다.

• 대한화학회지
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• 제39권5호
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• pp.364-370
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• 1995

비산화-환원 금속인 Ga(III), In(III), TI(III)을 포함하는 금속 포르피린을 촉매제로 NaOCl을 산화제로 하여 올레핀의 촉매적 산화반응을 $CH_2Cl_2$에서 연구하였다. 포르피린은 $(p-CH_3O)TPP,\;(p-CH_3)TPP,\;TPP,\;(p-F)TPP,\;(p-Cl)TPP $그리고 $(F_20)TPP$를 사용하였다. 올레핀은 $(p-CH_3O)-,\;(p-CH_3)-,\;(p-H)-,\;(p-F)-,\;(p-Cl)-,\;(p-Br)styrene$ 그리고 cyclopentene, cyclohexene을 사용하였다. 올레핀 산화반응에서 기질의 전환율(%)은 금속 포르피린 및 기질의 치환기 효과와 중심 금속이온 성질에 따라 고찰하였다. TPP 치환기에 따른 전환율의 변화는 $p-CH_3O$ < $p-CH_3$ < H < p-F < p-Cl 순서로 증가하였다. 이러한 증가는 TPP의 $4{\sigma}$값의 증가 순서와 일치하였다. 기질의 치환기에 따른 전환율의 변화는 $p-CH_3O$ > $p-CH_3$ > H > p-Cl > p-Br 순서로 치환기의 ${\sigma}^+$값이 증가할수록 오히려 감소하였다. 올레핀의 산화 반응에서 In(III)-, Tl(III)-포르피린은 Ga(III)-포르피린에 비하여 높은 촉매 활성을 나타내었다.

• 미생물학회지
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• 제36권4호
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• pp.254-258
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• 2000

소장의 상피세포내로 세균 세포가 들어가는 과정(invasion)은 Salmonella의 감염에서 중요한 단계이다. invasion은 Salmonella type III 분비장치에 의해 분비되는 단백질들에 의해 유도된다. type III 분비단백질들은 특이하게, 일반적인 분비단백질들이 가지는 N-말단 분비 신호 펩타이드를 가지고 있지 않는 것을 알려져 있다. Yersinia에서의 최근 연구에서 type III 분비장치에 의해 인지되는 분비신호는 분비 단백질을 암호화하는 mRNA의 5'말단부의가 형성하는 2차 구조에 있을 것이라는 보고가 있다. 본 연구에서는 Salmonella type III 분비장치의 분비신호를 조사하기 위해 type III 분비단백질중 하나인 sopE를 택하여 ompR과의 translational fusion을 만들었다. translational fusion을 위해 사용된 sopE DNA절편은 프로모터와 시작 콘돈으로부터 10, 15 코돈을 포함하는 절편이다. Immunoblot으로 확인한 결과, OmpR을 포함하는 fusion 단백질이 형질전환 Salmonella 세포로부터 분비되었다. 이러한 결과는 Salmonella의 type III 분비신호가 분비단백질을 암호화하는 mRNA의 5'말단에 위치할 가능성을 제시하고 있다. 또한, 이러한 분비신호를 활용하여 유용한 외래 단백질을 세균 세포 내에서 효과적으로 생산, 분비할 수 있는 secretion vector의 원형을 개발하였다.