• Journal of Food Hygiene and Safety
• /
• v.27 no.3
• /
• pp.224-232
• /
• 2012

This study was performed to investigate the pesticide residue of commercial medicinal plants used for food materials in the Seoul area. Multi class pesticide multiresidue methods in Korea Food Code was used to analyze 100 pesticides. Analyzed samples were 261 cases(domestic 201, imported 60), detection rate was 19.2%(domestic 20.9%, imports 13.3%). 17 pesticides were detected in fruit(chinese matrimony vine, jujube, rubus coreanus, japanese cornlian cherry, schizandra, tangerine peel), and root(cnidium, licorice, astragalus). Pesticide over Maximum Residue Limits were detected in jujube, cnidium. Frequently detected pesticides were cypermethrin, chlorpyrifos, cyhalothrin, fenvalerate, bifenthrin. More than 50% of the sample were detected two or more pesticides at the same time. Because of the variety and increase of pesticide detection in medicinal roots and fruits, continued monitoring and safety management is required.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.5
• /
• pp.605-612
• /
• 2005

In previous studies, we evaluated the effect of the 6 energy-tonic or blood-building prescriptions of traditional oriental medicine, and observed that Si-Wu-Tang and Bu-Zhong-Yi-Qi-Tang showed high activity in the protection of the gastrointestinal and hematopoietic organs in irradiated mice. But any of these prescriptions did not show a high activity in the activation of the immune cells. We performed this study to design an herb mixture which protects the self-renewal tissues and also promotes recovery of the immune system against radiation damage. In order to meet all the requirements, we designed a new mixture of 3 edible herbs listed in Korean Food Code. The mixture of Angelim gigas radix, Cnidium officinale rhizoma and Paeonia japonica radix was decocted with hot water, and the activities of the water extract (HIM-I) were evaluated. HIM-1 stimulated the immune cells in a much higher extent than the traditional prescriptions, and promoted dramatically the growth of bone marrow stem cells in vitro. Also, HIM-1 protected digestive and hematopoietic organs against radiation as effectively as the 2 prescriptions, Si-Wu-Tang and Bu-Zhong-Yi-Qi-Tang. On the other hand, it showed high in vitro antioxidative activity that might be considered as a mechanism of the protective effects against radiation. Although the detailed mechanisms of those effects remain to be elucidated, these results indicated that HIM-I might be a useful agent for protection and recovery of body from various risk factor as well as radiation, especially since it is a relatively nontoxic natural product.

• The Korean Journal of Nuclear Medicine
• /
• v.39 no.3
• /
• pp.191-199
• /
• 2005

Purpose: In order to obtain better quantitation of kidney uptake, this study is to evaluate a conjugate view method (CVM) using a geometric mean attenuation correction for kidney uptake and to compare it to Gate's method. Materials & Methods: We used a Monte Carlo code, SIMIND and a Zubal phantom, to simulate kidney uptake. SIMIND was both simulated with or without scatter for the Zubal phantom. Also, a real phantom test was carried out using a dual-head gamma camera. The activity of 0.5 mCi was infused into two small cylinder phantoms of 5 cm diameter, and then, they were inserted into a cylinder phantom of 20 cm diameter. The results by the CVM method were compared with ideal data without both of attenuation and scatter and with Gate's method. The CVM was performed with or without scatter correction. The Gate's method was performed without scatter correction and it was evaluated with regards to $0.12cm^{-1}\;and\;0.15cm^{-1}$ attenuation coefficients. Data were analyzed with comparisons of mean counts in the legions of interest (ROI), profiles drawn over kidney images and linear regression. Correlation coefficients were calculated with ideal data, as well. Results: In the case of the computer simulation, mean counts measured from ideal data, the CVM and the Gate's method were (right $998{\pm}209$, left: $896{\pm}249$), (right: $911{\pm}207$, left: $815{\pm}265$), and (right: $1065{\pm}267$, left: $1546{\pm}267$), respectively. The ideal data showed good correlation with the CVM and the correlation coefficients of the CVM, Gate's method were (right: 0.91, left: 0.93) and (right: 0.85, left: 0.90), respectively. Conclusion: The conjugate view method using geometric mean attenuation correction resulted in better accuracy than the Gate's method. In conclusion, the conjugate view method independent of renal depths may provide more accurate kidney uptake.

• Journal of Food Hygiene and Safety
• /
• v.33 no.2
• /
• pp.124-130
• /
• 2018

The Ministry of Food and Drug Safety (MFDS) is amending its test methods for the use of health functional foods (dietary food supplement), in order to establish regulatory standards and specifications in Korea. In this regard, we continue to pursue and perform our research on the analytical method development for the items being researched and reviewed. In this study, we have developed a sensitive and selective test method that could simultaneously separate and determinate six major bioactive flavonolignans in silymarin, which are based on the use of a liquid chromatographic-tandem mass spectrometry (LC-MS/MS). The standard calibration curves presented a linearity effect with the correlation coefficient ($r^2$) > 0.999. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of $0.3{\sim}9.0{\mu}g/L$ and $0.8{\sim}27.3{\mu}g/L$, respectively. The recovery results ranged between 96.2~98.6% at 3 different concentration levels, and its relative standard deviations (RSDs) were less than 5% as noted in this study. The proposed analytical method was characterized with a noted high resolution of the individual silymarin constituents, and the assay was fully validated as well. Our research can provide a significant scientific evidence that can be useful to amend the silymarin test method for the Health Functional Food Code.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.21 no.1
• /
• pp.65-73
• /
• 2019

The MODIS (Moderate Resolution Imaging Spectroradiometer) data in Hierarchical Data Format (HDF) have been processed using the Geospatial Data Abstraction Library (GDAL). Because of a relatively large data size, it would be preferable to build and install the data analysis tool with greater computing performance, which would differ by operating system and the form of distribution, e.g., source code or binary package. The objective of this study was to examine the performance of the GDAL for processing the HDF files, which would guide construction of a computer system for remote sensing data analysis. The differences in execution time were compared between environments under which the GDAL was installed. The wall clock time was measured after extracting data for each variable in the MODIS data file using a tool built lining against GDAL under a combination of operating systems (Ubuntu and openSUSE), compilers (GNU and Intel), and distribution forms. The MOD07 product, which contains atmosphere data, were processed for eight 2-D variables and two 3-D variables. The GDAL compiled with Intel compiler under Ubuntu had the shortest computation time. For openSUSE, the GDAL compiled using GNU and intel compilers had greater performance for 2-D and 3-D variables, respectively. It was found that the wall clock time was considerably long for the GDAL complied with "--with-hdf4=no" configuration option or RPM package manager under openSUSE. These results indicated that the choice of the environments under which the GDAL is installed, e.g., operation system or compiler, would have a considerable impact on the performance of a system for processing remote sensing data. Application of parallel computing approaches would improve the performance of the data processing for the HDF files, which merits further evaluation of these computational methods.

• (The)Study of the Eastern Classic
• /
• no.37
• /
• pp.63-91
• /
• 2009

This study presents an investigation into the Sahyang process and activities of the individuals whose Sahyang(receiving Gwanhyang from the king) was confirmed in the Shilrok documents of early Chosun among naturalized citizens(Hyanghwains). In early Chosun, there were four Chinese(Oh Jin, Lee Min-do, Dang Seong, and Mae Woo) in the Sahyang cases with more of those cases found among Hoigol-in(Seol Jang-soo, an Uighur) and Oioa-guk nationality(Lee Hyeon) from the countries bordering on Western China and two Japanese(Pyeong Sun and Pi Sang-ui). They were naturalized from the reign of King Chungryeol of Goryeo to the first year of King Jeongjong's reign of Chosun. They were diverse to include the great grandfather, grandfather, and father of the individual that received Gwanhyang and himself. There were one case of Sahyang during the reign of King Taejo, four during the reign of King Taejong, one during the reign of King Sejong, and three during the reign of King Sejo. The Gwanhyang they received was wide spread across the nation including Gyerim, Imju, Haeju, Sangju, Milyang, Chungju, Changwon, Dongrae, and Taean. It's very likely that the place of Sahyang was Cheohyang. Many of those who received Gwanhyang were translators and achieved great feats in Chosun's diplomacy with Ming Dynasty and Japan. There were also those who worked in medicine, art of divination, and articles of a criminal code. Seol Jang-su, who passed the state exam of Chosun, was in charge of Jigonggeo, and Lee Min-do and Dang Seong made a contribution to the establishment of Chosun and became big or small meritorious retainers at the founding of Chosun. It's all thanks to those performances that they had the honor of Sahyang of receiving Gwanhyang. Although they were the Gwanhyang with the honor of Sahyang, there is no confirmation of the descendents of the Lee family of Imju, the Pyeong family of Changwon, and the Pi family of Dongrae. While the descendents of the naturalized Chinese still remain in the nation, those of naturalized Japanese ceased to exist, which must be closely related to Chosun's perceptions of other nations those days.

• Journal of Food Hygiene and Safety
• /
• v.37 no.2
• /
• pp.69-79
• /
• 2022

The purpose of this study is to monitor the pesticide residues in frozen fruits and vegetables distributed and sold in online and offline markets in Korea. For the study, 107 samples of 34 types of frozen fruits and vegetables were examined, and a total of 341 pesticide residues were analyzed by using multiclass pesticide multi-residue methods of the Korean Food Code. As a result, pesticide residues were detected from 16 of 64 frozen fruits samples and 15 of 43 frozen vegetables samples. Conclusively, residues were detected from 31 samples in total, showing a detection rate of 29.0%. Specifically, pyridaben exceeded the Maximum Residue Limits (MRLs) based on the Positive list system (PLS) in one of the frozen radish leaves, and the violation rate was 0.9%. Detection on frozen fruits and vegetables was made 23 times for 11 types and 36 times for 21 types. In total, 28 types of pesticide residues were detected 59 times. Fungicides were detected the most in frozen fruits, while insecticides were detected the most in frozen vegetables. The most detected pesticides were the insecticide, acaricide chlorfenapyr (5) and the fungicide boscalid (5). Chlorfenapyr was detected only in frozen vegetables, and boscalid was detected in frozen fruits except one.

• Journal of the Korean Society of Radiology
• /
• v.16 no.4
• /
• pp.373-379
• /
• 2022

The radiation source used for non-destructive testing have permeability and cause a scattered radiation through collisions of surrounding materials, which causes changes in the surrounding spatial dose. Therefore, this study attempted to evaluate and analyze the distribution of spatial dose by source in the working environment during the non-destructive test using monte carlo simulation. In this study, Using FLUKA, a simulation code, simulates ⁶⁰Co, ¹⁹²Ir, and ⁷⁵Se source used in non-destructive testing, The reliability of the source term was secured by comparing the calculated dose rate with the data of the Health and Physics Association. After that, a non-destructive test in the radiation safety facility(RT-room) was designed to evaluate the spatial dose according to the distance from the source. As a result of the spatial dose evaluation, ⁷⁵Se source showed the lowest dose distribution in the frontal position and ⁶⁰Co source showed a dose rate of about 15 times higher than that of ⁷⁵Se and about 2 times higher than that of ¹⁹²Ir. In addition, the spatial dose according to the distance tends to decrease according to the distance inverse square law as the distance from the source increases. Exceptionally, ⁶⁰Co, ¹⁹²Ir, and ⁷⁵Se sources confirmed a slight increase within 2 m of position. Based on the results of this study, it is believed that it will be used as supplementary data for safety management of workers in radiation safety facilities during non-destructive testing using radioactive isotopes.

• Journal of Food Hygiene and Safety
• /
• v.37 no.4
• /
• pp.249-259
• /
• 2022

This study investigated pesticide residues in 7,069 agricultural products distributed in the city of Incheon from 2019 to 2021. Ingestion of pesticides can cause serious carcinogenic, endocrine, neurological, and reproductive problems. Pesticide residues in the samples were analyzed using various multi-residue methods (GC-MS/MS, GC-ECD/NPD, LC-MS/MS, and HPLC-UVD) on the Korean Food Code. The violation rate of the samples exceeding the maximum residue level (MRL) of pesticide residues for the years 2019, 2020, and 2021 was 1.0%, 1.4%, and 1.1%, respectively. Diazinon, flubendiamide, procymidone, fluxametamide, and fluquinconazole were the most frequently reported violative pesticide residues. Most commonly encountered agricultural products exceeding MRLs were coriander leaves, chamnamul, chwinamul, welsh onion, and crown daisy. Agricultural products and pesticides frequently exceeding MRLs should be continuously inspected for food safety. Continuous monitoring of pesticide residues in agricultural products is indispensable to improve consumer safety by preventing the distribution of agricultural products exceeding MRLs.

• Journal of the Korean Society of Radiology
• /
• v.17 no.4
• /
• pp.489-495
• /
• 2023

Radiation shielding facilities are constructed in locations where diagnostic radiation generators are installed, with the aim of preventing exposure for patients and radiation workers. The purpose of this study is seek to compare and validate the trend of attenuation thickness of lead, the primary material in these radiation shielding facilities, at different maximum tube voltages by Monte Carlo simulations and measurement. We employed the Monte Carlo N-Particle 6 simulation code. Within this simulation, we set a lead shielding arrangement, where the distance between the source and the lead sheet was set at 100 cm and the field of view was set at 10 × 10 cm². Additionally, we varied the tube voltages to encompass 80, 100, 120, and 140 kVp. We calculated energy spectra for each respective tube voltage and applied them in the simulations. Lead thicknesses corresponding to attenuation rates of 50, 70, 90, and 95% were determined for tube voltages of 80, 100, 120, and 140 kVp. For 80 kVp, the calculated thicknesses for these attenuation rates were 0.03, 0.08, 0.21, and 0.33 mm, respectively. For 100 kVp, the values were 0.05, 0.12, 0.30, and 0.50 mm. Similarly, for 120 kVp, they were 0.06, 0.14, 0.38, and 0.56 mm. Lastly, at 140 kVp, the corresponding thicknesses were 0.08, 0.16, 0.42, and 0.61 mm. Measurements were conducted to validate the calculated lead thicknesses. The radiation generator employed was the GE Healthcare Discovery XR 656, and the dosimeter used was the IBA MagicMax. The experimental results showed that at 80 kVp, the attenuation rates for different thicknesses were 43.56, 70.33, 89.85, and 93.05%, respectively. Similarly, at 100 kVp, the rates were 52.49, 72.26, 86.31, and 92.17%. For 120 kVp, the attenuation rates were 48.26, 71.18, 87.30, and 91.56%. Lastly, at 140 kVp, they were measured 50.45, 68.75, 89.95, and 91.65%. Upon comparing the simulation and experimental results, it was confirmed that the differences between the two values were within an average of approximately 3%. These research findings serve to validate the reliability of Monte Carlo simulations and could be employed as fundamental data for future radiation shielding facility construction.