• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2731-2736
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• 2012

The use of pyrimethamine as antibacterial drug is limited by the poor solubility. To enhance its solubility, we prepared complexes of pyrimethamine with low-molecular-weight succinoglycan isolated from Sinorhizobium meliloti. Low-molecular-weight succinoglycans are monomers, dimers, and trimers of the succinoglycan repeating unit. The monomers and dimers were separated into their three species (M1, M2, and M3) and four fractions (D1 to D4) using chromatographic techniques, which were shown to be nontoxic. The solubility of pyrimethamine was markedly increased up to 42 fold by succinoglycan D3, where the level of its solubility enhancement was even 8-20 fold higher comparing with cyclodextrin or its derivatives. The complex formation of succinoglycan D3 with pyrimethamine was confirmed by $^1H$ nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and molecular modeling studies. Herein, we suggest that the low-molecular-weight succinoglycans may be utilized as highly effective solubilizers of pyrimethamine for pharmaceutical purposes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.28-28
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• 2009

Fabrications of antireflection structures on solar cell were investigated to trap the light and to improve quantum efficiency. Introductions of patterned substrate or textured layer for Si solar cell were performed to prevent reflectance and to increase the path length of incoming light. However, it is difficult to deposit conformally flat electrode on perpendicular plane. ZnO is II-VI compound semiconductor and well-known wide band-gap material. It has similar electrical and optical properties as ITO, but it is nontoxic and stable. In this study, Al-doped ZnO thin films are deposited as transparent electrode by atomic layer deposition method to coat on Si substrate with micro-scale structures. The deposited AZO layer is flatted on horizontal plane as well as perpendicular one with conformal 200 nm thickness. The carrier concentration, mobility and resistivity of deposited AZO thin film on glass substrate were measured $1.4\times10^{20}cm^{-3}$, $93.3cm^2/Vs$, $4.732\times10^{-4}{\Omega}cm$ with high transmittance over 80%. The AZO films were coated with polyimide and performed selective polyimide stripping on head of column by reactive ion etching to measure resistance along columns surface. Current between the micro-columns flows onto the perpendicular plane of deposited AZO film with low resistance.

• 식물병연구
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• 제9권2호
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• pp.57-63
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• 2003

Clubroot disease of curcifer crops caused by Plasmodiophora brassicae had been first reported in 1928 in Korea, and maintained mild occurrence until 1980s. Since 1990s the disease has become severe in alpine areas of Kyonggi and Kangwon, gradually spread to plain fields throughout the country, and remains as the great-est limiting factor for its production. Researches on the disease has begun in late 1990s after experiencing severe epidemics. Survey of occurrence and etiological studies have been carried out, particularly, on the pathogen physiology, race identification, quantification of soil pathogen population, and host spectrum of the pathogen. Ecology of gall formation and its decay, yield loss assessment associated with time of infection, and relationships between crop rotation and the disease incidence was also studied during late 1990s. In studies of its control, more than 200 crucifer cultivars were evaluated for their resistance to the disease. Lime applica-tion to field soil was also attempted to reduce the disease incidence. Resistant radish and welsh onion were recommended as rotation crops with crucifers after 3-year field experiments. However, so for, most studies on clubroot disease in Korea have been focused on chemical control. Two fungicides, fluazinam and flusulfamide, were selected and extensively studied on their application technologies and combination effects with lime application or other soil treatment. To develop environmentally-friendly control methods, solar-disinfection of soil, phosphoric acid as a nontoxic compound, and root-parasiting endophytes as biocontrol agents were examined for their effects on the disease in fields. In the future, more researches are needed to be done on development of resistant varieties effective to several races of the pathogen, establishment of economically-sound crop rotation system, and improvement of soil-disinfection technique applicable to Korean field condi-tion, and development of methodology of pretreatment of fungicides onto seeds and seedbeds.

• 자원환경지질
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• 제37권4호
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• pp.383-389
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• 2004

지표 및 심토환경에서 물과 용액의 유동특성을 파악하는 것은 토양 및 지하수의 오염을 저감하고 방지하거나 기 오염 지역을 조사하고 정화하는데 있어서 필수적인 요소이다. 본 연구에서는 이 비형광, 비독성의 식용색소인 청색1호(Brilliant Blue FCF, $C_{37}H_{34}N_{2}Na_{2}O_{9}S_{3}$)를 염료 추적자로 이용하여 화강암에서 발달된 잔적토양에서의 침투 유형 및 그 특성을 조사하였다. 디지털 촬영된 수직 및 수평 착색영상은 지형정보 영상처리 프로그램인 ER Mapper, Version6.2를 이용하여 염료착색범위(dye coverage)로 전환되었다. 균질기반유동(homogeneous matrix flow)은 미약 입상 구조를 보이는 A 층위에서 발생하였으며, 상대적으로 세립조직인 A층위와 조립조직인 C층위의 경계에서는 선침투류(先浸透流, fingering)의 특징을 보여주었다. 모암인 화강암 조직의 기원인 거정질 광맥(pegmatitic vein)과 식물 뿌리는 C 층위에서 선택적 유동(preferential flow)을 유도하였음을 확인하였다.

• 한국유기농업학회지
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• 제26권3호
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• pp.501-514
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• 2018

본 논문은 가축의 면역 증진을 위한 천연 첨가제로서 좀민들레의 활용 가능성을 검토하고자 항산화 및 항염증 활성 평가를 실시하였다. 총 폴리페놀 및 플라보노이드 함량은 94.95, 86.33 mg/g으로 나타났고 DPPH, ABTS radical 소거능은 각각 100, $200{\mu}g/mL$의 농도에서 50%의 억제율을 보였으며, $1000{\mu}g/mL$에서 50%의 환원력을 나타냈다. LPS와 함께 처리한 Raw 264.7 cell에서는 좀민들레에 의한 세포 독성이 나타나지 않았으며 염증 매개 인자 NO와 염증성 사이도카인 $IL-1{\beta}$의 생성량을 유의하게 감소시켰다. 또한 염증성 단백질 발현량을 측정하기 위해 western blotting을 통해 확인한 결과, $400{\mu}g/mL$으로 처리하였을 때 LPS 처리구에 비해 염증성 단백질 발현 수준을 유의하게 감소시킨 것으로 확인되었다. 본 연구 결과, 좀민들레 추출물은 세포에 대한 독성이 없이 유의한 항산화 활성과 항염증 활성을 나타냄으로써 가축의 질병예방을 위한 면역 증진 및 생산성 향상에 기여할 수 있는 안전한 대체 천연 첨가제로 이용될 수 있다고 생각된다.

• 환경위생공학
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• 제15권3호
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• pp.88-93
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• 2000

VOCs의 촉매산화 공정에서 다성분 VOCs 혼합물의 간섭효과와 독성저감에 고나해 연구를 수행하였다. VOCs로는 benzene, toluene, styrene을 선정하였고, 0.5% $Pt/{\gamma}-Al_2O_3$를 촉매로 사용하였다. 각 VOCs의 반응성은 치환기의 종류에 따라 결합력이 다르기 때문에 benzene > toluene > styrene의 순으로 완전산화 반응이 잘 진행되었다. VOCs의 혼합물의 경우 각 VOCs는 서로 억제제로 작용하여 오나전산화 전환율을 감소시켰는데 이는 촉매표면에 각각의 VOCs가 경쟁 흡착하기 때문으로 styrene > toluene > benzene의 순으로 간섭효과가 크게 나타나는 것을 확인할 수 있었다. 이성분계 혼합 VOCs의 경우 혼합비에 따른 완전산화 전환율은 간섭효과가 작은 VOCs의 경우 상대 VOCs의 농도가 작을수록 전환율이 크게 나타났으며, 간섭효과가 큰 VOCs의 경우에는 상대 VOCs의 농도에 관계없이 자신의 부분농도에 반비레하는 현상을 보였다. 따라서 VOCs의 독성저감 기술로 촉매산화공정을 추천할 수 있으며, 실제공정과 같은 혼합물의 경우에도 단일성분의 전환특성과 혼합물의 간섭효과로부터 공정조건을 예측할 수 있을 것으로 사료된다.

• 대한핵의학회지
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• 제4권1호
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• pp.43-49
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• 1970

In recent years with development of immuno-electrophoresis, more acurate analysis of the serum protein became possible. However, there is few reports in the literature which investigated the changes of the immunoglobulin compared with electrophoretically fractioned serum thyroglobulin in the patients with various thyroid diseases. The purpose of this report is to investigate the changes of thyroglobulin in various thyroid diseases by the method of immuno-electrophoresis and to compare the results with.serum protein fractionated by the method of agar-gel micro-electrophoresis. Materials and Methods: Sera from 9 patients with diffuse toxic goiter, 2 nodular nontoxic goiter, 2 thyroiditis, 3 hypothy, roidism, 1 thyroid cancer, 7 cystic degeneration of the thyroid gland, and 10 normal subject were taken. All cases were confirmed by various laboratory thyroid function tests and thyroid needle biopsy. Immuno-electrophoretic analysis of the serum were performed by Scheidegger's modified micro-immuno-electrophoretic method. The antiserum was obtained from the Travenol Laboratories International, Hyland Products Division and was rabbit anti-human thyroglobulin. Microscope slide agar-gel electrophoresis for serum protein fractionation was performed at $4^{\circ}C$ using veronal buffer, pH 8.6 and ionic strength 0.05, with 54 volts and 2.8 mA for 60 minutes. The fractionated slide was stained with 0.1% thiazine red. The results were as follows: 1) Increase of immune-globulin macroglobulin (IgM), alphaglobulin, and immune-globulin A (IgA) by 95.8%, 100%, 29.2% respectively was found in the serum from various thyroid diseases. 2) Thyroglobulin fraction was found to be increased in 50%, no change in 41.7%, and no line in 8.3% with all of the various goiter patients. On the other hand, 10 normal control group showed only 2 cases of increase, 5 cases of no change and 3 cases of no line.

• Toxicological Research
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• 제22권2호
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• pp.95-102
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• 2006

Exposure to soluble nickel compound produces toxic effects on immune system, but the mechanism of action remains to be elucidated. Differential gene expression was studied to understand the potential molecular mechanism responsible for acute toxicity induced by nickel acetate in spleen cells. We exposed mouse spleen cells to nickel acetate with a nontoxic dose ($40{\mu}M$) and then extracted total RNA at 6 h and 12 h after exposure. The RNA was hybridized onto 10K mouse oligonucleotide microarrays, and data were analyzed using GeneSpring 7.1. Nickel had a modest effects on expression of many genes, in the range of 1.3-3 fold. The expression profile showed time-dependent changes in expression levels of differentially expressed genes, including some important genes related to cell cycle, apoptosis and DNA repair. In hierarchical cluster analysis of duplicate experiments, 111 genes were screened out. Out of these, 44 genes showing time- dependent up-regulation (>1.5 fold) and 38 genes showing down-regulation (>1.5 fold) at all time points were chosen for further analysis. The change in the expression of three genes (GPX1, GADD45B and FAIM) after nickel treatment was validated using RT-PCR. As a rule, a number of genes appear to be coordinately regulated between cell survival and cell death from nickel toxicity. In conclusion, changes in the gene profile in the spleen after nickel treatment are complex and genes with diverse functions are modulated. These findings will be contributed to the understanding of the complicated biological effects of nickel.

• Applied Microscopy
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• 제31권4호
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• pp.385-392
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• 2001

본 연구의 목적은 키토산올리고당의 쥐 간조직 독성여부를 관찰하고자 하였다. 건강한 Wistar계 쥐를 사용하였다. 실험군은 Group 1. 일반식이를 섭취한 대조군, Group 2 0.1%(1mg/ml)키토산올리고당 수용액을 30일 간 음용수를 통해 자유자재로 섭취시킨 후 교미시켜 태어난 $F_1$ 세대, Group 3 $F_1$ 세대의 쥐에게 0.1%(1 mg/ml) 키토산올리고당 수용액을 30일간 음용수를 통해 자유자재로 섭취한 후 교미시켜 태어난 $F_2$ 세대, Group 40.1% (1 mg/ml) 키토산올리고당 수용액을 90일간 음용수를 통해 자유자재로 섭취시킨 군, Group 50.1% (1 mg/ml) 키토산올리고당 수용액을 365일간 음용수를 통해 자유자재로 섭취시킨 군의 쥐 등으로 각 실험군 당 쥐 10마리를 사용하였고, 다음과 같은 결과를 얻었다. Group 4의 경우 약간의 소포체 팽창을 관찰하였을뿐, 다른 실험군에서는 대조군과 비교하여 특별한 간 조직의 미세구조 변화를 관찰하지 못하였다. 결론적으로 키토산올리고당은 무독성 물질로서 안전성이 있다고 사료된다.

• Fisheries and Aquatic Sciences
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• 제6권2호
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• pp.66-73
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• 2003

To understand the physiology of a suspension-feeding bivalve and its potential impacts on the dynamics of red tides on tidal flats, rates of clearance and ingestion of Glauconome chinensis were measured as a function of algal concentration, when the bivalve was fed on a nontoxic strain of red tide dinoflagellate Prorocentrum minimum, Cochlodinium polykrikoides or Scrippsiella trochoidea. With increasing algal concentration, weight-specific clearance rate increased rapidly at lower concentrations and after reaching the maximum at ca. 0.2 to 1.0 mgC/L, it decreased at higher concentrations. Maximum clearance rate was nearly equal for different algal species and ranged between 2.1 and 2.6 L/g/hr. Weight-specific ingestion rate also increased at lower algal concentrations but saturated at higher concentrations. Maximum ingestion rate was 2 to 10 fold different with different algal species: S. trochoidea (10.1 mgC/g/hr), P. minimum (3.9 mgC/g/hr), and C. polykrikoides (0.99 mgC/g/hr). Nitrogen and protein content showed that S. trochoidea is the best among the tested three red tide dinoflagellates. The maximum filtration capacity, calculated by combining the data on ingestion rate from laboratory experiments and those from the field for the density of the bivalve and the red tide dinoflagellates was 4.7, 1.4, and 25.3 tons/m2/day for P. minimum, C. polykrikoides, and S. trochoidea, respectively. It is hypothesized that the abundant suspension-feeding bivalves in tidal flats can effectively mitigate the outbreak of red tides.