• Korean Journal of Remote Sensing
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• v.27 no.4
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• pp.467-480
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• 2011

Spatial and temporal variabilities of NPP(Net Primary Production) retrieved from two satellite instruments, AVHRR(Advanced Very High Resolution Radiometer, 1981-2000) and MODIS(MODerate-resolution Imaging Spectroradiometer, 2000-2006), were investigated. The range of mean NPP from A VHRR and MODIS were estimated to be 894-1068 $g{\cdot}C/m^2$/yr and 610-694.90 $g{\cdot}C/m^2$/yr, respectively. The discrepancy of NPP between the two instruments is about 325 $g{\cdot}C/m^2$/yr, and MODIS product is generally closer to the ground measurement than AVHRR despite the limitation in direct comparison such as spatial resolution and vegetation classification. The higher NPP values over South Korea are related to the regions with higher biomass (e.g., mountains) and higher annual temperature. The interannual NPP trends from the two satellite products were computed, and both mean annual trends show continuous NPP increase; 2.14 $g{\cdot}C/m^2$/yr from AVHRR(1981-2000) and 6.08 $g{\cdot}C/m^2$/yr from MODIS (2000-2006) over South Korea. Specifically, the higher increasing trends over the Southwestern region are likely due to the increasing productivity of crop fields from sufficient irrigation and fertilizer use. The retrieved NPP shows a closer relationship between monthly temperature and precipitation, which results in maximum correlation during summer monsoons. The difference in the detection wavelength and model schemes during the retrieval can make a significant difference in the satellite products, and a better accuracy in the meterological and land use data and modeling applications will be necessary to improve the satellite-based NPP data.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.161-167
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• 2007

Purpose : GFR(glomerular filtration rate) is a fundamental parameter in detecting renal impairment and predicts the progression of renal disease. Because serum creatinine has several disadvantages, serum cystatin C has been recently proposed as a new endogenous marker for GFR. We compared serum cystatin C with creatinine and creatinine clearance to investigate the clinical usefulness of cystatin C. Methods : We retrospectively analyzed 46 patients(60 case numbers) who had various renal diseases and classified them into 3 groups according to creatinine clearance(Group 1 : CrCl <40 mL/min/$1.73m^2$, Group 2 : CrCl 40-60 mL/min/$1.73m^2$, Group 3 CrCl >60 mL/min/$1.73m^2$). We measured serum creatinine, cystatin C and creatinine clearance and also analyzed the correlations among them. Results : Serum cystatin C and creatinine showed a similar correlation to creatinine clearance (r=0.685, r=0.640, respectively) and showed similar diagnostic accuracy in detecting decreased GFR(AUC, cystatin C 0.829 vs. creatinine 0.826, P=0.848). Serum cystatin C showed a greater sensitivity for detecting a decreased GFR than creatinine in Group 2 and 3(Group 1 : 100% vs. 100%, Group 2 : 70% vs. 35%, Group 3 : 46% vs. 15%). Conclusions : Serum cystatin C could be a useful endogenous marker for GFR and would be superior to serum creatinine in early detection of renal impairment in pediatric patients with renal diseases.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.298-305
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• 2017

Benzovindiflupyr is a new pyrazole carboxamide fungicide that inhibits succinate dehydrogenase of mitochondrial respiratory chain. This study was carried out to develop an analytical method for the determination of benzovindiflupyr residues in agricultural commodities using LC-MS/MS. The benzovindiflupyr residues in samples were extracted by using acetonitrile, partitioned with dichloromethane, and then purified with silica solid phase extraction (SPE) cartridge. Correlation coefficient ($r^2$) of benzovindiflupyr standard solution was 0.99 over the calibration ranges ($0.001{\sim}0.5{\mu}g/mL$). Recovery tests were conducted on 5 representative agricultural commodities (mandarin, green pepper, potato, soybean, and hulled rice) to validate the analytical method. The recoveries ranged from 79.3% to 110.0% and then relative standard deviation (RSD) was less than 9.1%. Also the limit of detection (LOD) and limit of quantification (LOQ) were 0.0005 and 0.005 mg/kg, respectively. The recoveries of interlaboratory validation ranged from 83.4% to 117.3% and the coefficient of variation (CV) was 9.0%. All results were followed with Codex guideline (CAC/GL 40) and Ministry of Food and Safety guideline (MFDS, 2016). The proposed new analytical method proved to be accurate, effective, and sensitive for benzovindiflupyr determination and would be used as an official analytical method.

• Analytical Science and Technology
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• v.27 no.5
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• pp.234-242
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• 2014

Imicyafos which is a nematicide for controlling root-knot nematodes has been registered in the Republic of Korea in 2012, and the maximum residue limits of imicyafos are set to watermelon and korean melon as each 0.05 mg/kg. Extremely reliable and sensitive analytical method is required for ensuring food safety on imicyafos residues in agricultural commodities. Imicyafos residues in samples were extracted with acetone, partitioned with hexane and dichloromethane, and then purified with florisil. The purified samples were analyzed by HPLC-UVD and confirmed with LC-MS. Linear range was between 0.1~5 mg/kg with the correlation coefficient ($r^2$) 0.99997. Average recoveries of imicyafos ranged from 77.0 to 115.4% at the spiked levels of 0.02 and 0.05 mg/kg with the relative standard deviations of 2.2~9.6%. Limit of detection and quantification were 0.005 and 0.02 mg/kg, respectively. An inter-laboratory study was conducted to validate the determination method in depth, and the results were satisfactory. All of the validation results revealed that the developed analytical method in this study is relevant for imicyafos determination in agricultural commodities and will be used as an official analytical method.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.365-374
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• 2020

This study was conducted to monitor the residual pesticides on a total of 320 stalk and stem vegetables from January 2019 to December 2019 in the Incheon metropolitan area. Pesticide residues in samples were analyzed by the multi-residue method for 373 pesticides using GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD and HPLC-UVD. Risk assessment was also carried out based on the amount of stalk and stem vegetables consumed. The linearity correlation coefficient for the calibration curve was 0.9951 to 1.0000, LOD 0.002 to 0.022 mg/kg, LOQ 0.005 to 0.066 mg/kg and recovery was 82.0 to 108.0%. According to the monitoring of pesticides, 36 (11.3%) of 320 were detected with pesticide residues and 3 (0.9%) samples exceeded the maximum residual limit. The detection frequency for Chinese chives and Welsh onion was higher than that for other stalk and stem vegetables. The frequently detected pesticides were etofenprox, procymidone, fludioxonil, and pendimethalin. As a tool of risk assessment through the consumption of pesticide detectable agricultural products, the ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was calculated in the range of 0.0062-24.1423%. These results indicate that there is no particular health risk through consumption of commercial stalk and stem vegetables detected with pesticide residues.

• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.774-780
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• 2007

Purpose : The anthracyclines (AC) are widely used chemotherapeutic agents for pediatric cancers. However, the therapeutic use of these agents is limited by their cardiotoxicity. The aim of the present study was to investigate the usefulness of plasma B-type natriuretic peptide (BNP) levels as a marker for AC-induced cardiotoxicity compared to echocardiography in Korean children with cancer. Methods : Fifty-five pediatric cancer patients who had received chemotherapy including AC were enrolled. The cumulative AC doses, clinical symptoms, and two echocardiography parameters, left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF), were studied and compared with plasma BNP levels. Results : In 55 patients, plasma BNP levels were measured 115 times and echocardiographies were performed 64 times. The median cumulative dose of AC was $325mg/m^2$ (range 120-600; mean 345) and the median plasma BNP level was 10 pg/mL (range 5-950; mean 31). The cumulative AC doses correlated significantly with the plasma BNP levels (P=0.002). The plasma BNP levels correlated significantly with LVFS (P=0.018) and LVEF (P=0.025). Dilated cardiomyopathies were identified in three patients. LVFS and LVEF decreased and plasma BNP levels increased in a patient with acute dilated cardiomyopathy and in that with symptomatic chronic dilated cardiomyopathy. However, LVFS, LVEF and plasma BNP levels were normal in a patient with asymptomatic chronic dilated cardiomyopathy. Conclusion : The results of this study demonstrated that plasma BNP levels could be used as a marker for AC-induced cardiotoxicity; they showed good correlation with echocardiography findings in pediatric cancer patients. Plasma BNP levels may be used for the detection and management of AC-induced cardiotoxicity in Korean children with cancer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.646-652
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• 2017

The aim of this study was to investigate method validation for determination of sesamol, sesamin, and sesamolin in non-fermented sesame and fermented sesame by bioconversion. For validation, the specificity, linearity, precision, accuracy, limits of detection (LOD), and quantification (LOQ) of sesamol, sesamin, and sesamolin were measured by HPLC. Linearity tests showed that the coefficients of calibration correlation ($R^2$) for sesamol, sesamin, and sesamolin were 0.9999. Recovery rates of lignan contents in non-fermented and fermented sesame were high in the ranges of 100.27~115.10% and 98.43~114.90%, respectively. The inter-day and intra-day precisions of sesamin and sesamolin analyses for non-fermented and fermented sesame were 0.27~1.94% and 0.25~0.69%, respectively. The LOD and LOQ were $0.23{\sim}0.34{\mu}g/g$ and $0.70{\sim}1.03{\mu}g/g$, respectively. These results indicate that the validated method is appropriate for the determination of sesamol, sesamin, and sesamolin.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.766-775
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• 1998

Background : The prognosis of patients with lung cancer is still poor. Lung cancer exhibits a variable clinical outcome, even in those patients with same stage. Numerous reports suggest that oncogene expression might playa role in explaining the variability of response and survival But many of these reports are still under debate. So we studied the clinical relevance of oncogene expression in Korean lung cancer patients. Immunohistochemistry of p53, erbB-2, CEA expression was performed. Method: From March, 1992 until March, 1997, 120 patients with lung cancer were reviewed. p53, erbB-2, and CEA expression were detected on paraffin-embedded tumor blocks with the use of monoclonal antibodies. The survival and response has correlated with the expressibility of p53, erbB-2, and CEA oncoprotein Results: Overall, the expression rates of p53, erbB-2, and CEA were 33.7%, 59.3%, and 32.6% respectively. Expression rates were not correlated to cell type or stage. Compared with response to chemotherapy, no correlation was found. The expression of p53, erbB-2, or CEA was not correlated with 2-year survival. With simultaneous applications of p53, erbB-2, and CEA, patients with 2 or more expressions also did not show poor response to chemotherapy. Conclusion: We conclude the p53, erbB-2, and CEA expression are clinically less useful in predicting response to chemotherapy or survival.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.658-665
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• 2012

A survey of zearalenone contamination was conducted on cereal-based products by using an immunoaffinity column with LC-MS/MS. The calibration curve showed good lineality, with correlation coefficients ($R^2$) of 0.999 in the concentration range from 1 to 250 ng/mL. The limits of detection and quantification were approximately $0.3{\mu}g/kg$ and $1.0{\mu}g/kg$, respectively. The recoveries in the barley tea, Misutgaru and snack ranged from 73.6-107.8%. Zearalenone was detected in 10 samples (11.2% incidence). The highest zearalenone contamination level was $29.7{\mu}g/kg$ in the Misutgaru. This survey was conducted with uncertainty of measurement. The expanded uncertainty for zearalenone was estimated to be $44.9{\pm}5.0{\mu}g/kg$ (k=2, 95% confidence level) and $128.7{\pm}7.9{\mu}g/kg$ (k=2, 95% confidence level) for barley tea, $30.7{\pm}5.8{\mu}g/kg$ (k=2, 95% confidence level) and $173.7{\pm}14.9{\mu}g/kg$ (k=2.26, 95% confidence level) for Misutgaru, and $37.2{\pm}7.4{\mu}g/kg$ (k=2.31, 95% confidence level) and $151.0{\pm}10.4{\mu}g/kg$ (k=2, 95% confidence level) snack at the level of $41.7{\mu}g/kg$ and $166.7{\mu}g/kg$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1610-1616
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• 2016

This study aimed to establish an optimal extraction process and high performance liquid chromatography-ultraviolet (HPLC-UV) analytical method for determination of 3,5-dicaffeoylquinic acid (3,5-DCQA) as a part of materials standardization for the development of a xanthine oxidase inhibitor as a health functional food. The quantitative determination method of 3,5-DCQA as a marker compound was optimized by HPLC analysis using a Luna RP-18 column, and the correlation coefficient for the calibration curve showed good linearity of more than 0.9999 using a gradient eluent of water (1% acetic acid) and methanol as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 320 nm. The HPLC-UV method was applied successfully to quantification of the marker compound (3,5-DCQA) in Aster glehni extracts after validation of the method with linearity, accuracy, and precision. Ethanolic extracts of A. glehni (AGEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 30, 50, 70, and 80% ethanol for 3, 4, 5, and 6 h, respectively. Among AGEs, 70% AGE at $70^{\circ}C$ showed the highest content of 3,5-DCQA of $52.59{\pm}3.45mg/100g$ A. glehni. Furthermore, AGEs were analyzed for their inhibitory activities on uric acid production by the xanthine/xanthine oxidase system. The 70% AGE at $70^{\circ}C$ showed the most potent inhibitory activity with $IC_{50}$ values of $77.01{\pm}3.13{\sim}89.96{\pm}3.08{\mu}g/mL$. The results suggest that standardization of 3,5-DCQA in AGEs using HPLC-UV analysis would be an acceptable method for the development of health functional foods.