• 한국환경농학회지
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• 제41권4호
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• pp.355-364
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• 2022

BACKGROUND: Pre-harvest interval and decline pattern of thiamethoxam were determined in kiwifruit using liquid chromatography-tandem mass spectrometry (LCMS/MS). The study was carried out to propose import tolerance using OECD maximum residue limit (MRL) calculator for the export promotion of kiwifruit to Taiwan. METHODS AND RESULTS: The thiamethoxam residue in kiwifruit was determined by using the LC-TriQ-MS/MS with the analytical process to set up the import tolerance under greenhouse conditions for Taiwan. Excellent linearity was observed for all of the analytes with a determination coefficient (R²)≥0.99. The limit of quantification was determined to be 0.01 mg/kg for both thiamethoxam and clothianidin in kiwifruit. Linearity was determined from the co-efficient of determinants (R²) obtained from the seven-point calibration curve. The standard calibration curve showed as follows; 1) Site 1 (Gimje): y = 944,406X + 1,583 (R²=0.9995), 2) Site 2 (Goheung): y = 1,356,205X + 934 (R²=0.9983), and 3) Site 3 (Jangheung): y = 1,239,937X - 3,090 (R²=0.9908). The residue of thiamethoxam in the kiwifruit for three decline trials showed the range of 0.35 to 0.56 mg/kg in site 1 (Gimje), 0.24 to 0.55 mg/kg in site 2 (Goheung), and 0.28 to 0.42 mg/kg in site 3 (Jangheung), respectively. However, clothianidin was not detected in all of the treatments. The maximum residual amounts (decline) in the samples, sprayed according to the safe-use standard for thiamethoxam 10% WG in kiwifruit (30 days before harvest, 3 sprays every 7 days) were 0.56 mg/kg in site 1, 0.55 mg/kg in site 2, and 0.42 mg/kg in site 3, respectively. CONCLUSION(S): The import tolerance (IT) of thiamethoxam for kiwifruit may be proposed to be 0.9 mg/kg by using the OECD MRL calculator.

• 환경위생공학
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• 제13권2호
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• pp.115-120
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• 1998

This Study was performed to investigate the contents of aflatoxin $B_{1}$ in cereal, pulse, nuts and these products of domestic and import. These results were as follows. 1. Average concentration(in ${\mu}g/kg$) of aflatoxin $B_{1}$ in domestic foods were 2.6 in cereal, 3.9 in pulse, 4.2 in nuts and 1.4 grain products. The contents of aflatoxin B$_{1}$ in pulse and nuts were much higher than those of cereal and grain products. But their values were still within $10{\mu}g/kg$ the maximum residual level of aflatoxin $B_{1}$ for food of Korea. 2. Average contents of aflatoxin $B_{1}$ in import foods were 4.8, 5.4, 6.0, $3.8{\mu}g/kg$ for cereal pulse , nuts and popcorn & peanuts butter, respectively. And these values were found to be below the maximum residual level ($10{\mu}g/kg$) of aflatoxin $B_{1}$ for food of Korea. 3. The concentration of aflatoxin $B_{1}$ in 2 samples of domestic and 9 samples of import foods were over the tolerance limit for aflatoxin $B_{1}$ in food of Korea. Therefore, the hygienic managements of the foods should be required during storage and circulation at market.

• 한국환경농학회지
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• 제38권4호
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• pp.321-331
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• 2019

BACKGROUND: Pinoxaden is the phenylpyrazoline herbicide developed by Syngenta Crop Protection, Inc. and marketed on 2006. The maximum residue levels for wheat and barley were set by import tolerance. Thus, Ministry of Food and Drug Safety (MFDS) official analytical method determining Pinoxaden residue was necessary in various food matrixes. Satisfaction of international guideline of CODEX (Codex Alimentarius Commission CAC/GL 40) and National Institute of Food and Drug Safety Evaluation-MFDS (2017) are additional pre-requirements for analytical method. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was investigated to analyze residue of Pinoxaden (M4), which is defined as pesticide residue in Korea, in foods. METHODS AND RESULTS: Pinoxaden (M4) was extracted followed by acid digestion (2hr reflux with 1N HCl) and pH adjusting (pH 4-5 with 3% ammonium solution). To remove oil, additional clean-up step with hexane saturated with acetonitrile was required to high oil contained sample before purification. HLB cartridge and nylon syringe filter were used for purification. Then, samples were analyzed by LC-MS/MS using reserve phase column C₁₈. Five agricultural group representative commodities (mandarin, potato, soybean, hulled rice, and red pepper) were used to verify the method in this study. The liner matrix-matched calibration curves were confirmed with coefficient of determination (r²) > 0.99 at calibration range 0.002-0.2 mg/kg. The limits of detection and quantitation were 0.004 and 0.01 mg/kg, respectively, which were suitable to apply Positive List System (PLS). Mean average accuracies of pinoxaden (M4) were shown to be 74.0-105.7%. The precision of pinoxaden and its metabolites were also shown less than 14.5% for all five samples. CONCLUSION: The method investigated in this study was suitable to CODEX (CAC/GL 40) and National Institute of Food and Drug Safety Evaluation-MFDS (2017) guideline for residue analysis. Thus, this method can be useful for determining the residue in various food matrixes in routine analysis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.367-372
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• 2001

Feature restoration is that restore feature to 3D solid model using the feature information in STEP AP224. Feature is very important in CAPP, but feature information is defined very complicated in STEP AP224. This paper recommends the algorithm of extraction the feature information in physical STEP AP224file. This program import STEP AP224 file, parse the geometric and topological information, the tolerance data, and feature information line-by-line. After importation and parsing, store data into database. Feature restoration module analyze database including feature information, extract feature information, e.g. feature type, feature's parameter, etc., analyze the relationship and then restore feature to 3D solid model.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1142-1148
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• 2020

Mitochondria play a vital role in iron uptake and metabolism in pathogenic fungi, and also influence virulence and drug tolerance. However, the regulation of iron transport within the mitochondria of Cryptococcus neoformans, a causative agent of fungal meningoencephalitis in immunocompromised individuals, remains largely uncharacterized. In this study, we identified and functionally characterized Mrs3/4, a homolog of the Saccharomyces cerevisiae mitochondrial iron transporter, in C. neoformans var. grubii. A strain expressing an Mrs3/4-GFP fusion protein was generated, and the mitochondrial localization of the fusion protein was confirmed. Moreover, a mutant lacking the MRS3/4 gene was constructed; this mutant displayed significantly reduced mitochondrial iron and cellular heme accumulation. In addition, impaired mitochondrial iron-sulfur cluster metabolism and altered expression of genes required for iron uptake at the plasma membrane were observed in the mrs3/4 mutant, suggesting that Mrs3/4 is involved in iron import and metabolism in the mitochondria of C. neoformans. Using a murine model of cryptococcosis, we demonstrated that an mrs3/4 mutant is defective in survival and virulence. Taken together, our study suggests that Mrs3/4 is responsible for iron import in mitochondria and reveals a link between mitochondrial iron metabolism and the virulence of C. neoformans.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.162-162
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• 2017

Atractylodes japonica and Atractylodes macrocephala belongs to Atractylodes genus and theirs roots are used as 'Baek-chul'(White atractylodes rhizome) in Korea Pharmacopoeia. 'Baek-chul' widely used in traditional herbal remedies in Asia. Concurrently, the 'Baek-chul' demand enormously increased in the market due to the growing interest in favoring health benefits but it is depend on import from China. Thus we conducted breeding research to solve the problems associated with domestically cultivated 'Baek-chul' such as low productivity and low disease tolence. We crossed A. japonica (female parent) and A. macrocephala (male parent) in the greenhouse in September 2000. the next season 119 crossed line seeds were collected and germinated in the green house. Among them we selected the good lines in the same season. then conducted replicated yield trials (RYT) in 2014 to local adaptability test (LAT) in 2015-2016. The results showed that the 'AJM16' line has beneficial charactersitcs like, increased plant height, large rhizome diameter, narrow leaf width compared with a 'Sang-chul' (check cultivar) and varied flower color from A. japonica (female parent). The line 'AJM16' was also exhibited decreased anthracnose symptoms(Colletotrichum gloeosporides Penz.). Simultaneously the root yield of AJM16 was 2,409 kg per are, which was increased 130% higher yield compared to 'Sang-chul' (check cultivar) at three various regions from 2015 to 2016. Therefore, we named AJM16 as new cultivar 'Man-chul'. According the results, we have developed a new Atractylodes spp. hybrid cultivar 'Macn-chul' with high yielding and disease tolerance by National Institute of Horticulture and Herbal Science, RDA, in 2016.

• 한국철도학회논문집
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• 제9권3호
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• pp.282-290
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• 2006

In the current train operation system, large scaled stations like Cheongnyangni and Yongsan are not remote controlled from the central operator but manually by local operator. It is because there are so many entering and exit of trains between depot and mainline which are operating through the large scaled stations and it is very effective to traffic flow on the mainline. Therefore, Kyong Bong Technology Co., Ltd. (KBTech) and Korea Railway Research Institute (KRRI) are continuing the research and development to import 'Autonomous Decentralized System (ADS)'as part of a new train operation control system which is a national policy project of MOCT (Ministry Of Construction & Transportation). The concept of the 'Autonomous Decentralized System (ADS)' has born in 1970's in Japan by the influences of molecular biology. The special features of ADS are being a system that able to do the online expansion, online maintenance and fault tolerance. This thesis introduces the concept of technology of ADS and also describes the system designing & development to apply with large scaled stations.

• Journal of Plant Biotechnology
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• 제43권4호
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• pp.479-485
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• 2016

식품용 및 사료용 유전자변형작물은 매년 국내에 수입이 되고 있으며 유전자변형 캐놀라는 중요한 수입 작물 중의 하나이다. 유전자변형작물의 국내 재배는 허용되고 있지않지만 수입양은 매년 증가하고 있는 실정이다. 본 연구에서는 2009년부터 2013년까지 전국 9개 도를 대상으로 국내 수입된 유전자변형 캐놀라의 자연생태계 내 유출 정도를 파악하고자 모니터링을 실시하였다. 모니터링 조사는 항만, 사료공장, 축산농가, 운송로, 축제지 주변을 대상으로 실시하였다. 채집된 유전자변형 캐놀라 의심시료는 DNA에 기반을 둔 방법과 단백질에 기반을 둔 방법으로 분석하였다. 총 1850개 지점 조사에서 총 595개의 의심시료를 발견하였으며 6개의 유전자변형 캐놀라를 확인하였다. 국내 수입 승인된 단일이벤트 T45, MS8, RT73, Rf3, Topas 19-2의 primer를 사용한 PCR반응을 통해 2개의 glyphosate 저항성을 가지는 이벤트와 4 개의 glufosinate-ammonium에 저항성을 가지는 이벤트를 확인하였다. 본 연구를 통해 자연환경 모니터링 연구가 자연생태계 내의 유전자변형작물의 비의도적 유출을 예방하기 위해 매우 유용하다는 것을 알 수 있으며 사후관리를 수행하기 위한 기초자료를 구축하는데 활용될 것으로 사료된다.