• 한국환경과학회지
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• 제23권9호
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• pp.1635-1642
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• 2014

Haloacetic acids (HAAs) concentrations have been observed to decreased at drinking water distribution system extremities. This decrease is associated with microbiological degradation by pipe wall biofilm. The objective of this study was to evaluate HAAs degradation in a drinking water system in the presence of a biofilm and to identify the factors that influence this degradation. Degradation of monochloroacetic acid (MCAA), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) was observed in a simulated distribution system. The results obtained showed that different parameters came into play simultaneously in the degradation of HAAs, including retention time, water temperature, biomass, and composition of organic matter. Seasonal variations had a major effect on HAAs degradation and biomass quantity (ATP concentration) was lower by 25% in the winter compared with the summer.

• Applied Microscopy
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• 제8권1호
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• pp.67-76
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• 1978

A comparative investigation of fine structure of callus cells derived from tissue culture of Panax ginseng was made by electron microscope. Callus was consisted of large superficial cells and small inner zone cells derived from shoot apex tissue cultured for 16 weeks. Large superficial cells were contained the clusters of starch grains surrounded by a double plastid membrane. Especially, electron dense particles were deposited just inside and outside of plastid membrane and also deposited on mitochondria-like and endoplasmic reticulum-like structures. Crystalline body was also found in superficial cells. Small inner zone cells were characterized by presence of proplastids sheathed by short endoplasmic reticulum profiles. presence of spiral configuration of ribosomes and absence of crystalline body. Organ primordia was consisted of a dense cytoplasm and notable nucleate cells derived from nodal tissue cultured for 67 weeks. Proplastids containing starch grains and crystalline bodies were frequently observed; starch grains are of small quantity and does not form the clusters as in inner zone cells; hexagonal crystalline body itself does not have always limiting membrane. Remarkably. in a few cells of primordia, particles resembling the presumptive virus were observed mainly in condensed nuclear chromatin and also in cytoplasm, in mitochondrion-like organelle.

• Toxicological Research
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• 제34권2호
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• pp.127-132
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• 2018

Alcohol consumption triggers toxic effect to organs and tissues in the human body. The risks are essentially thought to be related to ethanol content in alcoholic beverages. The identification of ethanol in blood samples requires rapid, minimal sample handling, and non-destructive analysis, such as Raman Spectroscopy. This study aims to apply Raman Spectroscopy for identification of ethanol in blood samples. Silver nanoparticles were synthesized to obtain Surface Enhanced Raman Spectroscopy (SERS) spectra of blood samples. The SERS spectra were used for Partial Least Square (PLS) for determining ethanol quantitatively. To apply PLS method, $920{\sim}820cm^{-1}$ band interval was chosen and the spectral changes of the observed concentrations statistically associated with each other. The blood samples were examined according to this model and the quantity of ethanol was determined as that: first a calibration method was established. A strong relationship was observed between known concentration values and the values obtained by PLS method ($R^2=1$). Second instead of then, quantities of ethanol in 40 blood samples were predicted according to the calibration method. Quantitative analysis of the ethanol in the blood was done by analyzing the data obtained by Raman spectroscopy and the PLS method.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.171-175
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• 2006

Chitin compost and broth were used to suppress club root. Individual cabbage seedlings were transplanted into pots(3500 ml) containing a mixture of 3% chitin compost and 50 ml of chitin broth (T1) or the same quantity control compost and control compost broth(T2). The media in each pot was then infected with Plasmodiophora brassicae. Samples were taken at 6, 7 and 8 weeks after transplanting. The population of chitinase producing bacteria in T1 was consistently larger than that observed in T2. Chitinase activity in the T1 rhizosphere was two-fold greater than that of T2 at each time point observed. Shoot dry weight, leaf number and leaf area in T1 were enhanced 20%, 10% and 12% relative to those seen in T2, respectively. The disease index and root mortality at 8 weeks after transplanting were reduced by 50% and 25% in T1 compared to T2, respectively. Results presented in this study are strongly indicative that chitin compost and broth suppress clubroot in Chinese cabbage.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.929-942
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• 1999

Three beagle dogs aged over one and half years were used in this study. All mandibular premolars were carefully extracted. Two AVANA implants(Sumin, Korea) and two 3i implants(Implant Innovation, USA) were installed at each right and left side respectively. Each dog was sacrificed at 4, 8. 12 weeks. Non-decalcified specimens were made and stained for a light microscopic study. The results were as follows ; 1. Inflammation was not observed in the area of bone tissue adjacent to the implant body. 2. With time, quantity of osseointe-gration increased in each type of den-dental implant. There was no difference between AVANA implant and 3i implant. 3. Maturation of the bone around each type of the dental implant increased with time. 12 weeks after implant installation, the bone around dental implant represented compact bone-like appreance. 4. In case implants were located adjacent to a root, newly-formed periodontal ligament tissue was observed around the implant. And the direction of the periodontal ligament fiber was parallel to the surface of the implant . Within the results of this study, AVANA implants represented similar osseointegra-tion in comparision with 3i implants.

• 설비공학논문집
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• 제18권10호
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• pp.842-849
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• 2006

In this study, the effect of carbon nanotubes (CNTs) on boiling heat transfer is investigated. Three refrigerants of R22, R123, R134a, and water are used as base working fluids and 1% of CNTs by volume is added to the base fluids to study the effect of CNTs. All data are obtained at the pool temperature of $7^{\circ}C$ for all refrigerants and $100^{\circ}C$ for water in the heat flux range of $10{\sim}80\;kW/m^2$. Test results show that CNTs increase the boiling heat transfer coefficients for all fluids. Especially, large enhancement was observed at low heat flutes. With increasing heat flux, however, the enhancement was suppressed due to vigorous bubble generations. Fouling was not observed during the course of this study. Optimum quantity and type of CNTs and their dispersion should be examined for their application in pool boiling heat transfer.

• 한국치위생학회지
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• 제24권2호
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• pp.131-139
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• 2024

Objectives: Oral bacterial samples included subgingival, supragingival, and saliva plaques. As the diversity and number of microorganisms deffer depending on the area of the oral cavity and the method used, an appropriate and reliable collection method is important. The present study investigated oral bacterial sampling methods. Methods: Supragingival dental plaque was collected from the buccal and lingual tooth surfaces of study participants using sterilized cotton swabs. Plaques were collected from the subgingival area using a sterilized curette. Bacterial genomic DNA was extracted using MagNA Pure 96 DNA and Viral NA low-volume kits. Real-time polymerase chain reaction (PCR) was performed using the PowerCheck^TM Periodontitis Pathogens Multiplex Real-time PCR kit. Results: Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Fusobacterium nucleatum of the orange complex were not observed in the subgingival biofilms of all study participants. For Porphyromonas. gingivalis, a significant correlation was observed between supragingival, subgingival, and total tooth surface biofilms. Compared to the supragingival and subgingival biofilmss, total tooth surface biofilm exhibited the highest bacterial count when the inswabbing method was used. Conclusions: Based on these findings, the supragingival swab method is recommended for oral bacterial research.

• 한국식품영양학회지
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• 제24권4호
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• pp.528-534
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• 2011

추출용매와 조작순서를 달리하여 원료인삼 및 압출성형 가공시 인삼의 사포닌 함량 및 항산화 정도의 변화를 알아보기 위하여 인삼과 압출성형한 가공 인삼의 80% 에탄올 엑기스, 에틸아세테이트 분획, 수포화 부탄올 분획, 수층 분획을 각각 얻은 후 LC/MASS를 사용하여 사포닌 함량을 조사하고 기존의 여러 가지 항산화 작용 측정 방법들의 오류를 없애고 더욱 정확한 결과를 낼 수 있는 대처 방안으로 선정된 ORAC 분석법에 의해 항산화 활성을 검토하였다. 검체 인삼 중 사포닌은 ginsenoside Rb1과 Rg1 및 Re를 주요 성분으로 다량 함유하고 있었으며, Rb2, Rc, Rd 등이 뒤를 이었고, 그밖에도 Rg3, Rh1가 미량 분포하고 있었다. 압출 성형 인삼의 경우 원료 인삼에 비해 전반적으로 사포닌 함량이 높았으며, 주로 ginsenoside Re와 Rb1 및 Re가 많았고, 그밖에 Rc, Rb2, Rg1, Rh, Rd 등이었으며, 특히 원료인삼에서 미량 존재하던 Rh1과 Rg3가 많이 증가함을 보였다. 이러한 현상은 압출인삼의 에틸아세테이트층과 부탄올층에서도 같은 경향을 보였다. 원료 인삼의 에틸아세테이트층에서는 Rg1 함량이 높았고, 압출인삼에서는 Rh1과 Rg3가 많이 용출되었으며, Rg1, Re, Rb1 등이 용출되었다. ORAC 분석법에 의한 항산화 활성 연구에서 원료인삼 중의 여러 생리활성 성분이 많이 함유되어 있는 80% 에탄올 추출 분획과 일반적으로 극성의 사포닌 성분을 많이 함유한 수포화 부탄올층의 항산화 활성은 에틸아세테이트층과 수층에 비해 높았으나, 압출성형과정을 거치더라도 유의성 있는 증가는 없었다. 그러나 압출성형과정을 거친 압출 인삼의 에틸아세테이트층과 수층 분획이 대조 원료인삼의 각각의 분획들에 비해 모두 유의성($p$ >0.05)있는 증가를 보였다. 또한 원료인삼과 압출 인삼의 80% 에탄올 추출 엑기스, 에틸 아세테이트 분획, 수포화 부탄올 분획, 수층 분획 모두에서 일정 수준의 항산화 활성을 나태내고 있음을 확인할 수 있었고, 특히 인삼사포닌을 거의 함유하지 않은 원료인삼과 압출 인삼의 수층에서도 항산화 활성을 나타내었다. 이는 인삼 중 항산화 활성은 에틸아세테이트 층으로 이행되는 폴리페놀 계통 성분 및 일부 비극성의 사포닌에 의한 것으로 추측되고 있으나, 모든 분획에서 나타난 것으로 보아 이들 외에 산성 다당체, 당단백질, 수용성 다당류, 말톨 등 다른 생리 활성 물질에 대한 연구가 요구된다.

• 한국응용곤충학회지
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• 제46권1호
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• pp.153-158
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• 2007

콩의 생식생장기에 노린재류의 밀도조사법을 개발하고자 하였다. 타락법, 포충망법 및 달관법으로 콩의 개화기(R2), 결협기(R4) 및 성숙기(R7)에 발생하는 톱다리개미허리노린재, 가로줄노린재, 풀색노린재, 알락수염노린재 및 썩덩나무노린재의 성충과 약충의 밀도를 조사한 결과 노린재류의 총 조사량은 타락법에서 5,214.2마리로 가장 많았으며, 다음은 달관법에서 2,581.8마리 였으며, 포충망법에서 103.1마리로 가장 적었다. 타락법과 달관법에 의한 노린재류의 총 조사량은 가로줄노린재 > 풀색노린재 > 썩덩나무노린재 > 톱다리개미허리노린재 > 알락수염노린재의 순서로 많았고, 발생량의 차이도 분명하였으나, 포충망법에 의한 노린재류의 총 조사량은 18-23마리로 발생량의 차이가 분명하지 않았다. 따라서 타락법에 의한 주요 노린재류의 조사밀도는 톱다리개미허리노린재 성충을 제외하곤 대체로 높았다. 하지만 타락법보다 불출법으로 콩의 개화시부터 성숙까지 톱다리개미허리노린재의 성충을 더 많이 조사할 수 있었고, 일중 조사량은 오후시간대보다 오전시간대에 많았다. 그러므로 콩포장에서 노린재류의 밀도조사법으로 톱다리개미허리노린재는 불출법으로, 가로줄노린재, 풀색노린재, 알락수염노린재 및 썩덩나무노린재는 타락법이 추천되었다. 이러한 2가지 조사법의 적용은 노린재류의 종간 행동적 특성 차이 때문이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1667-1669
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• 2004

In this paper, the elastic epoxy added elastomer having viscoelasticity to existing epoxy was measured thermal, structural properties by DSC (Differential Scanning Calorimetry) and FESEM (Field Emission Scanning Electron Microscope). Specimens were made of dumbbell forms by the ratio of 5, 10, 15, and 20[phr] by regulation with elastomer contents. The measurement temperature dimensions of DSC were -20[$^{\circ}C$] to 150[$^{\circ}C$] and rising temperature was 4[$^{\circ}C$/min]. Also we observed structure through FESEM at the magnification of 1000 times with the voltage of 15[kV] after breaking by quenching specimens. As experimental results, we could know that thermal and structural properties were improved quantity according to decrease of elastomer contents. Namely, it increased glass transition temperature, high temperature, and matrix structure. In general, thermal, structural properties of 15[phr] was excellent among the specimens.