• 대한핵의학회지
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• 제34권4호
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• pp.336-343
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• 2000

목적: $[^{201}Tl]$TICI주사액의 제조과정에서 안정동위원소인 $^{201}Tl$ 및 Cu, Pb의 중금속을 함유할 가능성이 있어 이러한 이물질을 확인하기 위한 방법으로 방사성 물질의 대기오염을 일으키지 않는 폴라로그래피의 분석 조건을 설정하고자 하였다. 대상 및 방법: 원자력병원에서 생산하고 있는 $[^{201}Tl]$-TlCl 주사액에 포함될 수 있는 중금속을 대상으로 하였다. 극미량의 중금속을 측정하기 위한 방법으로 BAS-50W 폴라로그래피를 이용하였고, 여기에 사용된 3 전극계는 작업전극인 DME, 기준전극인 Ag/AgCl 그리고 보조전극인 백금선을 이용하였다. 신속하고 재현성있는 분석을 위한 조건으로 기기의 분석 모드, 각 모드에 적합한 전극, 지지전해질, 석출시간 등의 치적 조건을 설정하였다. 결과: 폴라로그래피의 모드는 OSWSV 방법이 재현성과 감도면에서 가장 우수하였고, 작업전극은 DME와 Au 전극을 비교 실험한 결과 재현성 면에서 DME가 보다 좋은 결과를 보였다. 지지전해질은 염기성인 0.50 M KOH 용액, 산성인 1.0 M $HNO_3$, 용액, 중 성인 pH 7 phosphate 완충용액을 비교 실험하여 pH 7 phosphate 완충용액이 $Tl^+$과 $Cu^{2+}$를 분석하는데 가장 적합함을 확인하였다. 이를 바탕으로 중금속을 측정한 결과 $Tl^+$은 -450 mV, $Cu^{2+}$는 -50 mV에서 각각의 피크가 나타났고, 석출시간을 45초로 하였을 때 $Tl^+$의 경우 y=2.05E-$9{\chi}$+5.66E-9이고 $Cu^{2+}$의 경우는 y=1.23E-$8{\chi}$+1.23E-6의 선형 관계식을 얻었다. 결론: 이 방법에 의한 Tl과 Cu의 검출한계는 약 0.05 ppm이다. 이 방법을 현재 원자력병원에서 생산하고 있는 $[^{201}Tl]$TICl 주사액의 정도관리에 도입하여 중금속을 측정한 결과 약전에서 규정하고 있는 2 ppm 미만임을 확인하였고, 그 결과는 재현성, 정확도, 감도 및 간편성에서 모두 만족할 수 있었다. 이 방법은 $[^{201}Tl]$TlCl 주사액 뿐만 아니라 $^{67}Ga$ 주사액 및 기타 방사성의약품과 중금속 분석에도 응용할 수 있다.

• 한국토양비료학회지
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• 제49권5호
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• pp.589-597
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• 2016

There are a number of industrial complexes which could be a source of heavy metal (loid)s contamination of arable soil in Gyeongnam province of South Korea. Heavy metal (loid)s accumulation of plant is more related to the concentration of plant available heavy metal (loid)s in arable soil than that of total heavy metal (loid)s. The objectives of this study were 1) to examine heavy metal concentrations in soils located near industrial complexes in Gyeongnam province and 2) to determine the relationship between concentration of plant available heavy metal (loid)s and chemical properties of soil. Soil samples were collected from 85 sites of arable lands nearby 7 industrial complexes in Gyeongnam province. Total heavy metal (loid)s concentration, available heavy metal (loid)s concentration, and chemical properties of collected soils were measured. The mean concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in the soils were $5.8mg\;kg^{-1}$, $1.3mg\;kg^{-1}$, $0.03mg\;kg^{-1}$, $51.5mg\;kg^{-1}$, and $68.7mg\;kg^{-1}$, respectively. Total concentration of Cd and Zn in arable soil located near ${\nabla}{\nabla}$ industrial complex exceeded the warning criteria ($4mg\;kg^{-1}$ and $300mg\;kg^{-1}$ for Cd and Zn, respectively) as described by in the soil environmental conservation Act of Korea. The concentration of plant available heavy metal (loid)s was negatively related to the soil pH and available Pb and Zn concentrations had relatively high correlation coefficient when compared with other heavy metal (loid)s. The concentration of plant available Pb and Zn was negatively related to that of organic matter (OM). Based on the above results, it might be a good soil management to control pH and OM concentration with soil amendments such as lime and compost to reduce phytoavailability of heavy metal (loid)s in arable soil located near industrial complex.

• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1156-1167
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• 2018

The aim of this study was to isolate and characterize lead (Pb)-solubilizing bacteria from heavy metal-contaminated mine soils and to evaluate their inoculation effects on the growth and Pb absorption of Brassica juncea. The isolates were also evaluated for their plant growth-promoting characteristics as well as heavy metal and salt tolerance. A total of 171 Pb-tolerant isolates were identified, of which only 15 bacterial strains were able to produce clear haloes in solid medium containing PbO or $PbCO_3$, indicating Pb solubilization. All of these 15 strains were also able to dissolve the Pb minerals in a liquid medium, which was accompanied by significant decreases in pH values of the medium. Based on 16S rRNA gene sequence analysis, the Pb-solubilizing strains belonged to genera Bacillus, Paenibacillus, Brevibacterium, and Staphylococcus. A majority of the Pb-solubilizing strains were able to produce indole acetic acid and siderophores to different extents. Two of the Pb-solubilizing isolates were able to solubilize inorganic phosphate as well. Some of the strains displayed tolerance to different heavy metals and to salt stress and were able to grow in a wide pH range. Inoculation with two selected Pb-solubilizing and plant growth-promoting strains, (i.e., Brevibacterium frigoritolerans YSP40 and Bacillus paralicheniformis YSP151) and their consortium enhanced the growth and Pb uptake of B. juncea plants grown in a metal-contaminated soil. The bacterial strains isolated in this study are promising candidates to develop novel microbe-assisted phytoremediation strategies for metal-contaminated soils.

• 환경영향평가
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• 제5권2호
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• pp.21-31
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• 1996

To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.

• 대한치과보철학회지
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• 제14권1호
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• pp.17-21
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• 1976

The author studied the gingival responses to some dental cements in the gingival sulcus around artificial crowns. Abutment preparation for full veneer crown was performed in the canines of the two dogs. The location of cervical margins was about 0.5mm. below the gingival crest. Niranium metal crowns were constructed for the teeth, and cemented with zinc phosphate cement or polycarboxy late cement. In the experimental groups the retained cements in the gingival sulucus were not removed, and in the control groups the cements were removed completely after cementation. The dogs were sacrificed at 3 weeks and 5 weeks respectively after cementation. The gingival responses to these cements were examined histologically. The findings were as follows. 1. There was severe inflammation in the gingiva where the cements had been retained in the gingival sulcus around artificial crowns. 2. There was more severe inflammation in the gingiva which had contacted with zinc phosphate cement than in the gingiva with polycarboxylate cement. 3. There was mild inflammation in the gingiva around the margins of Niranium crowns. 4. The retained cement around the margin of restoration should be completely removed after cementation.

• 분석과학
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• 제5권1호
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• pp.33-39
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• 1992

리튬이온의 새로운 중성운반체로서 tetrahydrofuran 단위의 16고리형 crown-4를 퓨란과 아세톤으로부터 산 촉매하에서 합성하여 수소화시킨 후 리튬-이온과의 착물형성반응을 Li-7 NMR과 전기전도도법으로 조사했다. 합성한 리간드를 PVC-액체막 전극에 사용하여 분리용액법에 의한 리튬이온의 선택성을 결정하였다. 막용매, tris(2-ethylhexyl) phosphate에서 리튬이온의 선택계수는 알칼리금속이온 및 알칼리토금속이온에 대해 $2.4{\times}10^{-1}$에서 $2.3{\times}10^{-4}$ 범위의 값을 가졌으며, 산성용액(pH=2 이하, 0.1M LiCl)에서 액체막은 $H^+$ 이온의 방해로 불안정하였다.

• BMB Reports
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• 제42권8호
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• pp.523-528
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• 2009

Phosphomannose isomerase (PMI) catalyzes the interconversion of fructose-6-phosphate and mannose-6-phosphate in the extracellular polysaccharide (EPS) synthesis pathway. The gene encoding PMI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli. The pmi gene is 1,410 nucleotides long and the deduced amino acid sequence shares high homology with other bifunctional proteins that possess both PMI and GDP-mannose pyrophosphorylase (GMP) activities. The sequence analysis of PMI revealed two domains with three conserved motifs: a GMP domain at the N-terminus and a PMI domain at the C-terminus. Enzyme assays using the PMI protein confirmed its bifunctional activity. Both activities required divalent metal ions such as $Co^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $Ni^{2+}$ or $Zn^{2+}$. Of these ions, $Co^{2+}$ was found to be the most effective activator of PMI. GDP-D-mannose was found to inhibit the PMI activity, suggesting feedback regulation of this pathway.

• 대한화학회지
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• 제19권5호
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• pp.325-330
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• 1975

철(III) 이온과 인산간의 착물형성에 관하여 넓은 인산산성범위(0${\sim}40{\%}$)에서 가시부스펙트럼과 용액으로 부터 분리해낸 화합물을 검토함으로써 연구하였다. 철(III)함유 인산용액의 전자흡수 스펙트럼은 19.2kK 및 24.1kK에서 철(III)-인산 착물형성을 나타내는 두개의 가시부 흡수를 나타내었다. 24.1kK 밴드의 인산농도에 따른 흡광도 변화의 측정으로부터 아마도 $[Fe(H_xPO_4)]^{x+}\;및\;[Fe_2 (H_xPO_4)]^{(3+x)+}$등 두개의 형태가 틀린 철(III)-인산착물이 존재함을 알 수 있었다. 이들 두화합물중 몰비가 1:1인 착물은 고체상태로 분리하는데 성공하였으며 인산이온은 염기도 1인 상태로 금속에 배위되어 있음을 알 수 있으나, 이합체로 생각되는 화합물은 분리해낼 수 없었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.475-479
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• 2003

미더덕으로부터 GAGs는 1/60 M sodium phosphate buffer로 $105^{\circ}C$로 열수 추출하는 것이 가장 경제적인 것으로 나타났다. 이렇게 추출한 GAGs의 $SO_4$ 함량은 31.2%, 회분 함량은 22.2%이다 회분 함량의 증가는 sodium phosphate의 사용으로 추정되며, 이것은 무기질 분석에서 Na의 함량이 총 무기질의 47.6%를 차지하고 있다는 것으로 뒷받침한다. 일반 성분, HPLC 분석, 당 분석, 아미노산 분석의 결과로 GAGs의 주된 구조는 glucosamine과 galacturonic acid로 결합되어 있으며, 당과 단백질은 threonine으로 연결되어 있다는 것을 알 수 있다. 화장품 원료 규격에 적합한 제단백은 5.0%, 10.0%, 20.0% TCA(w/v) 처리, 10.0%, 20.0%, 40.0% HCl(v/v) 처리, UF(ultra filteration)를 포함한 10.0% TCA(w/v), 20.0% S-SAS(w/v), 25.0% HCl(v/v) 처리가 가능하며, 이중 5.0% TCA(w/v) 및 10.0% HCl(v/v)의 처리가 가장 경제적이며 효율적이라는 것을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1018-1021
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• 2010

Metallic and non-metallic isomerases can be used to produce commercially important monosaccharides. To determine which category of isomerase is more suitable as a template for directed evolution to improve enzymes for galactose isomerization, L-arabinose isomerase from Escherichia coli (ECAI; E.C. 5.3.1.4) and tagatose-6-phosphate isomerase from Staphylococcus aureus (SATI; E.C. 5.3.1.26) were chosen as models of a metallic and non-metallic isomerase, respectively. Random mutations were introduced into the genes encoding ECAI and SATI at the same rate, resulting in the generation of 515 mutants of each isomerase. The isomerization activity of each of the mutants toward a non-natural substrate (galactose) was then measured. With an average mutation rate of 0.2 mutations/kb, 47.5% of the mutated ECAIs showed an increase in activity compared with wild-type ECAI, and the remaining 52.5% showed a decrease in activity. Among the mutated SATIs, 58.6% showed an increase in activity, whereas 41.4% showed a decrease in activity. Mutant clones showing a significant change in relative activity were sequenced and specific increases in activity were measured. The maximum increase in activity achieved by mutation of ECAI was 130%, and that for SATI was 190%. Based on these results, the characteristics of the different isomerases are discussed in terms of their usefulness for directed evolution of non-natural substrate isomerization.