• 한국진공학회지
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• 제14권3호
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• pp.119-125
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• 2005

원자로의 중성자 빔을 사용하는 수평형 반사율 장치는 중성자 고유의 투과성 및 낮은 에너지의 비파괴성과 함께 시편을 수평으로 놓을 수 있는 장점을 가지고 수 나노미터 이내의 박막의 두께와 밀도를 측정하기 위하여 활용되는 새로운 장치이다. 원자력연구소에 열 중성자를 기반으로 개발을 추진하고 있으나, 아직 국내에 설치되어 있지 않아서 장치의 개념 및 최적화를 위한 시뮬레이션이 시급하다. 따라서 열중성자에 해당하는 $2.5{\AA}$를 기반으로 몬테카를로 시뮬레이션을 이용하는 MCSTAS를 이용하여 장치의 개념을 설계하였다. 단색기와 collimator, 그리고 초거울등의 설계 및 각 변수들은 설계의 목표인 최대 Flux를 갖는 중성자 빔 세기를 고려하여 결정하였다.

• 한국잡초학회지
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• 제14권1호
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• pp.71-80
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• 1994

Nepal, with its unique geographical and ecological features due to its abrupt rise in altitude, plays significant role in biological evolution. Existence of numerous wild relatives of the present-day cultivated agricultural crop plants in this small Himalayan nation may serve as a potential source of several yet unidentified desirable genes that are needed for future incorporation in the improvement of cultivated crop plants. This report includes 82 different wild relatives of 41 genera under 19 families of 37 agricultural crops of Nepal(Table 1). It serves as the sample of the glossary of these wild relatives of crop plants in Nepal. Under food grain crop plants of gramineae, leguminoceae and polygonaceae families, 16 different wild species namely wild rices(7 species), wild relatives of wheat plant(3 species), wild arhar(3 species), wild fingermillets(1 species) and wild buckwheat(2 species) have been identified in different parts of the country. Similarly, under vegetable crop plants of Araceae, Amaranthaceae, Crucifereae, Cucurbitaceae, Dioscoreaceae, Labiteae, Leguminosae, Liliaceae, Malvaceae, Polygonaceae, Solanaceae and Umbellifereae, 37 different wild species-wild colocasia(1 species), wild amaranths(3 species), wild leafy vegetables(2 species), wild gourds(3 species), wild cucumber(1 species), wild yams(4 species), wild mints(3 species), wild fenugreeks(4 species), wild pea(1 species), wild beans(3 species), wild garlics(2 species), wild spinach(3 species), wild lady's finger(1 species), wild spinach(3 species), wild eggplants(2 species) and wild carrot(one species) have also been identified. In case of wild relatives of cultivated orchard plants, 11 different wild species namely wild mango(one species), wild banana(one species), wild strawberry(one species), wild pear(one species), wild cherries(2 species), wild apple(one species) and wild grapes(3 species) have been identified, Among 19 different wild species of economic crop plants, five wild species of sugarcane, one species of wild sunhemp, two wild relatives of cotton, three wild relatives of rose, two wild species of tobacco, four wild species of turmeric and two wild species of tea have also been identified. This report includes only sample of the total wild species of the present-day cultivated agricultural crop plants. Further exploration on this economic botany will help the country in cataloging the wild relatives of cultivated crop plants and their future use in crop improvement.

• 한국환경농학회지
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• 제39권2호
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• pp.142-169
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• 2020

BACKGROUND: A new analytical method has been developed to determine 261 pesticide residues in herbal medicines. METHODS AND RESULTS: The extraction of pesticides was carried out by modified method of the Korea Food Standards Codex sample extraction and determination was performed using GC-MS/MS and LC-MS/MS. During the pre-treatment process of the test method, Solid-liquid separation was changed to centrifugation. The method was validated by the precision and accuracy results. 261 pesticides spiked at three level 20, 50, 100 ug/kg in herbal medicines. The limit of quantification of method were 4-40 ug/kg for GC-MS/MS and 2-45 ug/kg for LC-MS/MS, respectively. Among the pesticides analysed by GC-MS/MS and LC-MS/MS, 244 pesticides (94% of total number) in chinese matrimony vine and 224 pesticides (86% of total number) in korean angelica root and 231 pesticides (89% of total number) in jujube and 214 (82% of total number) in cnidium showed recoveries in the range of 70-120% with RSD⪯20%. CONCLUSION: These results indicated that GC-MS/MS and LC-MS/MS analysis with the sample extraction in this study can be applied to multi-residue analysis of pesticides in herbal medicines.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.387-394
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• 1995

박막광도파로 센서의 특소전파상수를 이용하여 인간혈액내의 산화 및 환원 혈색소의 흡광계수를 쉽고 빠르게 측정할 수 있는 방법을 제안한다. 제작된 광도파로위에 에바네센트 필드와 시료간의 상호작용길이를 변화시킬수 있도록 직렬의 다채널 시료 충전셀을 만들고 여러가지 농도의 두가지 혈색소 시료들에 대한 센서응답을 조사하여 상호작용길이에 대한 의존성을 살펴보았다. 센서응답은 상호작용길이와 시료의 농도에 선형적으로 비례한다. 시료들과 에바네센트 필드 흡수에 따른 제작된 센서의 감쇄정수를 실험적으로 구하고 제한된 방법으로 흡광계수를 결정한다. 제안된 방법으로 구한 두가지 혈색소에 대한 흡광계수는 종래의 투과광 측정법으로 구한 값과 잘 일치한다.

• KSBB Journal
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• 제20권2호
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• pp.71-75
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• 2005

2D-Gel 이미지간의 유사성을 기준으로 생물학적인 시료가 프로테옴 수준에서 유사성의 정도와 서로 다른 단백질 스팟을 파악해 낼 수 있다. 그러나 생물학적인 시료는 개체간 변화가 크고 2차원 전기영동장치의 재현성의 한계로 인하여 비교가 어려운 경우가 많고 의미 없는 차이점만 발견되는 경우 또한 비일비재하다. 이를 극복하기 위해서는 프로테옴 이미지간의 정렬을 통하여 정확한 비교가 가능하게 하여야한다. 본 연구에서는 이미지상의 단백질 스팟을 일일이 찾지 않고 여러 개의 원시 이미지를 동시에 정렬시키는 multiresolution-multilevel algorithm을 활용하여 소프트웨어를 개발하였다. 또 이렇게 정렬된 이미지들이 서로 얼마나 유사한지 보여주는 Phylogenetic tree를 자동으로 생성시키는 소프트웨어를 개발하였다. 이 방법을 이용하여 Fetal Alcohol Syndrome의 case와 control의 10개의 프로테옴 이미지에 대하여 클러스터링을 시도하였다. 이와 같이 2D-Gel 프로테옴 전체의 이미지를 비교하여 유사한 정도에 따라 모으는 클러스터링은 FAS 시료의 경우 case와 control 보다는 시료원의 외연적인 특징인 나이 혹은 성별에 더 의하여 의존하는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제21권3호
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• pp.267-273
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• 2011

Methyl violet, used extensively in the commercial textile industry and as a biological stain, is a hazardous recalcitrant. Aspergillus sp. strain CB-TKL-1 isolated from a water sample from Tsumoriri Lake, Karzok, Ladakh, India, was found to completely decolorize methyl violet within 24 h when cultured under aerobic conditions at $25^{\circ}C$. The rate of decolorization was determined by monitoring the decrease in the absorbance maxima of the dye by UV-visible spectroscopy. The decolorization of methyl violet was optimal at pH 5.5 and $30^{\circ}C$ when agitated at 200 rpm. Addition of glucose or arabinose (2%) as a carbon source and sodium nitrate or soyapeptone (0.2%) as a nitrogen source enhanced the decolorization ability of the culture. Furthermore, the culture exhibited a maximum decolorization rate of methyl violet after 24 h when the C:N ratio was 10. Nine N-demethylated decolorized products of methyl violet were identified based on UV-visible spectroscopy, Fourier transform infrared (FTIR), and LC-MS analyses. The decolorization of methyl violet at the end of 24 h generated mono-, di-, tri-, tetra-, penta-, and hexa-N-demethylated intermediates of pararosaniline. The variation of the relative absorption peaks in the decolorized sample indicated a linear decrease of hexa-N-demethylated compounds to non-N-demethylated pararosaniline, indicating a stepwise N-demethylation in the decolorization process.

• Environmental Analysis Health and Toxicology
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• 제11권1_2호
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• pp.31-39
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• 1996

Leachate from municipal solid waste (MSW) landfill, effluent from leachate treatment plant, and ground water sample from a monitoring well near landfill site were tested for an acute toxicity. Microtox toxicity test was used for testing the acute toxicity of leachate and other samples. EC$_{50}$ values which a concentration of pollutant for reducing 50% light output from luminescent bacteria, Photobacterium phosphoreum were determined to assess the toxicity of pollutants as well as the relative toxicity. In addition, characteristics of leachate were studied and compared to those of phenol and pentachlorophenol (PCP) which are typical aquatic toxic pollutants. For leachate, EC$_{50}$ for 30 min incubation was 10.8%, while for phenol and PCP, 46 ppm and 1.2 ppm, respectively. the relative toxicity of treated leachate by in situ aeration with activated sludge was reduced to more than 75% of toxicity of the untreated leachate. Microtox toxicity test was failed to figure out EC$_{50}$ values for groundwater from a monitoring well since the relative toxicity of the unconcentrated sample was too low to estimate EC$_{50}$. Addition of activated carbon to leachate was reduced the relative toxicity. The reduction Pattern of the relative toxicity of leachate by mechanical aeration was similar to that of PCP, but different from that of phenol. These findings suggest that the toxicity of leachate may come from PCP-like toxic compounds rather than phenol-like one. In conclusion, the process of aeration with activated sludge might be very important to reduce the environmental toxicity of leachate. And Microtox test could be a reasonable bioassay for screening and monitoring the environmental toxicity of leachate from municipal solid waste landfill as well as for determining the reduction efficiency of the leachate toxicity by various treatment processes in leachate treatment plant.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2156-2162
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• 2012

Many literatures focus on the biological relevance and the identification of biomarkers for disease activity assessment while less attention has been paid to the development of standard procedures for sample preparation and storage based on liquid chromatography technique. The influencing factors including protein precipitation, storage temperature, storage time, and reconstitution by ultra pure water were analyzed employing HPLC-DAD. The effects were investigated from five participants over three months by principal components analysis (PCA) and the values of percent changes (PC). The samples with protein precipitation might slow the rate of bacterial enzymatic conversion. After protein precipitation, the average PC of urine samples ($0.136{\pm}0.013$, n = 5) is relatively less than that of the serum samples ($0.173{\pm}0.026$, n = 5) for three months. Minimal effects on metabolic profiles of serum and urine (PC < 0.15) are reasonable for metabolomic studies after protein precipitation and storage at $-20^{\circ}C$ for two months.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.884-892
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• 2020

Corticosterone is known as a biological stress index in many species including birds. Feather corticosterone concentration (FCC) has increasingly been used as a measure for chronic stress status in broiler chickens. As sample preparation is the first step of analytical process, different techniques of feather matrix disruption need to be validated for obtaining better result in analysing corticosterone extraction. The current study was a validation of pulverizing the feather by bead beater (BB) and surgical scissors (SS) processing prior to corticosterone extraction in feather of broiler chickens. The type of feather processing prior to the hormone extraction may alter the final output. Thereby, finding a standard method according to laboratory facilities is pivotal. This study carried out to determine the effects of feather pulverization methods on the extraction amount of corticosterone in broiler chickens. Feathers were sampled from four weeks old Ross 308 broiler chickens (n = 12 birds). All broiler chickens were kept under the same environmental condition and had access to feed and water. Feather samples were assigned to one of the following processing methods 1) using a BB for pulverizing and 2) using a SS for chopping into tiny pieces. Each sample was duplicated into two wells during enzyme immunoassay (EIA) analysis to improve the accuracy of the obtained data. The results showed lower standard errors and constant output of FCC by using the BB method compared with the SS method. Overall comparison of FCC showed a significantly higher (p < 0.001) amount of the FCC in the BB compared with the SS. Overall, using the BB method is recommended over the SS method for feather processing due to the ability to homogenize a large number of samples simultaneously, ease of use and greater extraction of feather corticosterone.

• 한국식품영양학회지
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• 제34권6호
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• pp.584-592
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• 2021

In this study, the antioxidant activity of methanol extracts of wheat sprouts grown in wild fields and cultivated fields and harvested at various times were analyzed to compare the quality characteristics of the wheat sprouts as a function of their cultivation and harvest time, as well as for the development of functional materials. The total polyphenolic and flavonoid content, as well as antioxidant activity of the wheat extracts, were subsequently analyzed. The ABTS radical scavenging activity of the wheat extract increased from 16.97 mg TEAC/g sample on cultivation day three in cultivated field wheat sprouts to 25.99 mg TEAC/g sample after seven days of wild field cultivation. The total polyphenol content increased from 17.08 mg GA eq/100 g in cultivated field wheat sprouts grown for three days to 28.70 mg GA eq/100 g after seven days of wild field cultivation. In addition, the flavonoid content increased from 7.02 mg catechin eq/100 g (7 days) to 8.47 mg/g after 12 days of wild field cultivation. Notably, the activity subsequently decreased. These results suggest that the wheat sprouts with higher biological activity were those produced from the wild field after 20 days.