• 한국환경농학회지
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• 제30권3호
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• pp.323-329
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• 2011

BACKGROUND: The conazoles, difenoconazole, diniconazole, hexaconazole, penconazole and tetraconazole are a large class of synthetic fungicides used extensively for foliage and seed treatments in agricultural crops. The extensive use of conazoles has brought concerns on the potentiality of environmental contamination and toxicity. Thus studies on the development of methods for monitoring the conazoles are required. METHODS AND RESULTS: A modified quick, easy, effective, rugged and safe (QuEChERS) method was involved in sample preparation. Quadrapole time of flight mass spectrometer (Q-TOF MS) in electron spray ionization (ESI) mode was employed to determine conazoles in garlic samples. The limit of detection (LOD) and limit of quantification (LOQ) of conazoles by Q-TOF-MS ranged from 0.001 to 0.002 mg/L and 0.002 to 0.005 mg/L, respectively. Q-TOF-MS analysis exhibited less than 2.6 ppm error of accurate mass measurements for the detection of conazoles spiked at 0.05 mg/L in garlic matrix. Recovery values of conazoles fortified in garlic samples at 0.02, 0.05 and 0.1 mg/L were between 79.2 and 106.2% with a maximum 11.8% of standard deviation. No detectable conazoles were found in the domestic market samples by using the Q-TOF-MS method. CONCLUSION(s): High degree of confirmation for conazoles by accurate mass measurements demonstrated that Q-TOF-MS analysis combined with a QuEChERS method may be applicable to simultaneous determination of conazoles in garlic samples.

• 대한원격탐사학회지
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• 제19권4호
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• pp.271-276
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• 2003

복합위성자료 신호처리기법을 사용해서 남인도양 지역을 중심으로 한 해수면변화와 사행 (meandering)을 연구하였다. 해수면변화는 아프리카 남부(46$^{\circ}$E)에서 크호제트 대지(Crozet basin)의 35$^{\circ}$~46$^{\circ}$S대를 걸쳐서 암스테르담-케르겔른 경로(Amsterdam-Kerguelen Passage)까지 확장된다. 이때 가장 강한 해수면변화(20~30cm)가 2개의 좁은 지역에서 발생하는데, 하나는 경도 49$^{\circ}$~57$^{\circ}$E(약 700Km) 및 위도 38$^{\circ}$~42$^{\circ}$S(약 450Km)나타났고 그리고 나머지 하나는 경도 58$^{\circ}$~64$^{\circ}$E(약 450Km) 및 위도 42$^{\circ}$~44$^{\circ}$S(약 200Km)에서 각각 나타났다. 이것은 해저지형과 관련된 강한 와동류의 형성 때문이다. 와동류 발생지역은 아규라스반류(Agulhas Return Current) 및 남극순환해류(Antarctic Circumpolar Current)와 관련하여 강한 흐름이 형성되는 지역에서 발생했다. 이때 복합위성자료(Topex/Poseidon, ERS1)는 표층순환과 해수면변동 특성을 잘 나타내었다.

• 한국환경농학회지
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• 제42권3호
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• pp.220-230
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• 2023

Imidacloprid is a neonicotinoid insecticide widely used for insect control in a variety of crops. The evaluation of imidacloprid total residues in animal feeds derived from crop by-products is required to ensure the safety of livestock products. We performed simultaneous LC/MS/MS analyses of imidacloprid and its metabolites in five different livestock products including beef, pork, chicken, milk and egg from domestic markets. The methods for sample preparation and instrumental analysis were established by modifying QuEChERS method to meet the Codex guidelines. The methods generated 0.0035 mg/kg of the limit of determination (LOD), 0.01 mg/kg of the limit of quantitation (LOQ) and standard calibration linearity with >0.983 of the coefficients of determination (R²). The methods exhibited the recovery values of imidacloprid and its metabolites ranging from 65.66 to 119.27% without any interference between matrices. Imidacloprid total residues in the livestock products were found as values lower than the LOQ and maximum residue limits (MRLs). This study suggests that the methods are successfully applicable for the safety evaluation of imidacloprid total residues in livestock products from domestic markets.

• 대한임상검사과학회지
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• 제55권4호
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• pp.276-283
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• 2023

산업안전보건연구원에서는 현재 2005년 미국흉부학회(American Thoracic Society, ATS)와 유럽호흡기학회(European Respiratory Society, ERS)의 폐활량검사 표준화가이드를 준용하여 근로자건강진단 폐활량검사를 평가하고 있으며, 2019년 ATS/ERS가이드의 적용을 검토하고 있다. 새로운 평가기준에 따른 결과를 현재 결과와 비교해보고 우리나라 근로자건강진단에 적용하는 것이 적절한지 확인하기 위해 특수건강진단기관으로부터 수집한 325건의 폐활량검사 결과를 검토하였다. 외삽용적, 보정오차, FIVC 등의 평가기준을 더 엄격하게 적용하였음에도 검사의 신뢰성 점수가 상승한 기관이 더 많았다. 주요원인은 FEV1, FVC의 적합성과 재현성을 분리하여 판단함과 동시에 점수를 ATS 등급에 따라 차별 부여하므로 감점 폭이 감소했기 때문으로 파악된다. 새로운 기준을 적용하면 현재 부적합하다고 판단하는 자료의 활용이 가능하므로 검사자와 판정의사의 결과선별과 해석에 대한 이해도를 높인다면 검사자와 수검자 모두가 검사에 대한 부담감을 줄이면서 신뢰성 있는 결과를 얻을 수 있을 것으로 기대한다.

• The Korean Journal of Physiology and Pharmacology
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• 제28권2호
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• pp.129-143
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• 2024

Sulfur dioxide (SO₂), a novel endogenous gas signaling molecule, is involved in the regulation of cardiac function. Exerting a key role in progression of hyperthyroidism-induced cardiomyopathy (HTC), myocardial fibrosis is mainly caused by myocardial apoptosis, leading to poor treatment outcomes and prognoses. This study aimed to investigate the effect of SO₂ on the hyperthyroidism-induced myocardial fibrosis and the underlying regulatory mechanisms. Elisa, Masson staining, Western-Blot, transmission electron microscope, and immunofluorescence were employed to evaluate the myocardial interstitial collagen deposition, endoplasmic reticulum stress (ERS), apoptosis, changes in endogenous SO₂, and Hippo pathways from in vitro and in vivo experiments. The study results indicated that the hyperthyroidism-induced myocardial fibrosis was accompanied by decreased cardiac function, and down-regulated ERS, apoptosis, and endogenous SO₂-producing enzyme aspartate aminotransferase (AAT)1/2 in cardiac myocytes. In contrast, exogenous SO₂ donors improved cardiac function, reduced myocardial interstitial collagen deposition, up-regulated AAT1/2, antagonized ERS and apoptosis, and inhibited excessive activation of Hippo pathway in hyperthyroid rats. In conclusion, the results herein suggested that SO₂ inhibited the overactivation of the Hippo pathway, antagonized ERS and apoptosis, and alleviated myocardial fibrosis in hyperthyroid rats. Therefore, this study was expected to identify intervention targets and new strategies for prevention and treatment of HTC.

• 농약과학회지
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• 제17권4호
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• pp.264-270
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• 2013

Imidacloprid는 곤충의 신경 독으로 작용하는 침투성 살충제이며, 과일과 채소에 진딧물 등의 해충 방제에 이용되고 있다. 침투성 농약은 작물체 내부로 흡수 이동되어 다양한 대사산물들이 생성되며 이중 일부 대사산물들은 농산물의 안전성에 문제가 되기도 한다. 따라서 농약과 대사산물의 동시분석법은 작물체 내에서 농약의 동태연구 및 농산물의 안전성을 확인하기 위해 필요하다. 본 연구의 목적은 고추 식물체 내에서 imidacloprid와 그 대사산물 4종, imidacloprid urea, imidacloprid olefin, idmidalcoprid guanidine, 그리고 6-chloronicotininic acid의 QuEChERS 법과 LC-MS/MS 시스템을 사용한 동시 분석법을 개발하고자 하였다. 실험방법은 고추 식물체 시료에 1% glacial acetic acid와 아세토니트릴 첨가한 후 추출하였고 그 추출물을 일정량 분취한 후 PSA와 $C_{18}$을 이용하여 정제하였다. 정제된 추출물은 LC-MS/MS로 분석하였으며, 표준정량곡선은 혼합표준용액(Matrix matched standard)를 제조하여 작성하였다. 표준정량곡선의 상관계수는 0.998 이상이었으며, LOQ도 0.05 mg/kg 이하였다. 0.01, 0.04, 0.1, 0.4 mg/kg 4개 수준으로 회수율시험을 수행하였으며, 그 결과 imidacloprid와 그 대사산물의 회수율은 70~120%이었고, RSD는 20%이하였다. 이러한 결과는 본 시험방법이 고추 식물체에서 imidacloprid 및 그 대사산물을 분석하는데 적합하다는 것을 보여준다.

• 농약과학회지
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• 제15권4호
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• pp.401-416
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• 2011

최근 농식품 중 잔류농약의 분석을 위해서 전처리를 빠르고 단순하게 하면서 고감도의 정밀기기를 이용하여 정성 및 정량을 동시에 행하는 분석방법의 개발이 확대되고 있다. 따라서 신속한 전처리법으로 빠르게 확산되고 있는 QuEChERS(quick, easy, cheap, effective, rugged and safe)법과 PTV(programmable temperature vaporizer)가 장착된 GC/TOFMS을 이용하여 분석법을 개발하였다. PTV조건을 확립했으며 사과 시료를 대상으로 3농도 수준에서(50, 100, 400 ng/g) QuEChERS법(acetate buffer법)으로 전처리 한 후 PTV-GC/TOFMS로 분석하여 회수율 및 RSD를 조사한 결과 400 ng/g 농도에서는 230성분(97%)이 80-120%의 회수율을 보였으며 5성분(2.1%)을 제외한 모든 성분에서 RSD값이 10%미만으로 양호한 재현성을 보였다. 가장 낮은 농도인 50 ng/g의 경우에서는 검출되지 않은 33성분을 제외한 203성분 중 197성분(97%)에서 70-120%의 회수율을 보였으며, 4성분(2.0%)을 제외한 모든 성분에서 RSD값이 20%미만으로 나타났다. 따라서 본 연구에서 확립된 QuEChERS 전처리법과 PTV-GC/TOFMS 분석조건을 이용하여 과일과 야채중의 잔류농약 분석이 가능할 것으로 보였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.590-593
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• 2004

Extraction of ocean surface current velocity offers important physical oceanographic parameters especially on understanding ocean environment. Although Remote Sensing techniques were highly developed, the investigation of ocean surface current using Synthetic Aperture Radar (SAR) is not an easy task. This paper presents the results of ocean surface current observation using Doppler Centroid of ERS-1 SAR data obtained off the coast of Korea peninsula. We employed the concept, in which Doppler frequency shift and the ocean surface current are closely related, to evaluate ocean surface current. Moving targets cause Doppler frequency shift of the back scattered radar waves of SAR, thus the line-of-sight velocity component of the scatters can be evaluated. The Doppler frequency shift can be measured by estimating the difference between Doppler Centroid of raw SAR data and reference Doppler Centroid. Theoretically, the Doppler Centroid is zero; however, squinted antenna which is affected by several physical factors causes Doppler Centroid to be nonzero. The reference Doppler Centroid can be obtained from measurements of sensor trajectory, attitude and Earth model. The estimated Doppler Centroid was compensated by considering the accurate attitude estimation of ERS-1 SAR. We could verify the correspondence between the estimated ocean surface current and observed in-situ data in the error bound.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.633-633
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• 2002

We investigated the distributions of sea ice using various microwave remote sensing techniques in the part of Drake passage, Antarctica, between the area 45-75$^{\circ}$W and 55-66$^{\circ}$S. We used Topex/Poseidon(T/P) radar altimeter, ERS-1 altimeter, ERS-2 scatterometer, Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), and DMSP Special Sensor Microwave/Imager(SSM/I) data. The sea ice distributions were estimated between May and Jun., 1995 and Oct. and Nov., 1998. The two altimeter measurements (T/P and ERS-1) showed good coherence with the results from the radiometer data in the given period when the ice concentration of 20% and greater was selected. The scatterometer data also showed good correlation with altimetry-implied sea ice surface. The maximum and minimum values of sea ice distribution were appeared in Aug. and Feb., respectively. In general, the sea ice distributions estimated from radar altimeter, radioneter, and scatterometer are well correlated.

• 대한원격탐사학회지
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• 제10권2호
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• pp.49-62
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• 1994

Look direction bias in a single look SAR image can often be misinterpreted in the geological application of radar data. This paper investigates digital processing techniques for SAR image data integration and compensation of the SAR data look direction bias. The two important approaches for reducing look direction bias and integration of multiple SAR data sets are (1) principal component analysis (PCA), and (2) wavelet transform(WT) integration techniques. These two methods were investigated and tested with the ERS-1 (VV-polarization) and CCRS*s airborne (HH-polarization) C-SAR image data sets recorded over the Sudbury test site, Canada. The PCA technique has been very effective for integration of more than two layers of digital image data. When there only two sets of SAR data are available, the PCA thchnique requires at least one more set of auxiliary data for proper rendition of the fine surface features. The WT processing approach of SAR data integration utilizes the property which decomposes images into approximated image ( low frequencies) characterizing the spatially large and relatively distinct structures, and detailed image (high frequencies) in which the information on detailed fine structures are preserved. The test results with the ERS-1and CCRS*s C-SAR data indicate that the new WT approach is more efficient and robust in enhancibng the fine details of the multiple SAR images than the PCA approach.