• Journal of Mushroom
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• v.19 no.1
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• pp.51-55
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• 2021

The mineral contents of domestic and Chinese Sarcodon aspratus were analyzed for comparing the differences in the mineral contents according to the production sites. The mineral contents of 10 domestic and 10 Chinese S. aspratus were analyzed by using an atomic absorption spectrophotometer and an inductively coupled plasma mass spectrometer. The sodium, magnesium, potassium, and calcium contents of domestic S. aspratus were 170.3±44.0 mg/kg, 81.3±20.8 mg/kg, 1,123.8±274.3 mg/kg, and 12.1±4.1 mg/kg, respectively, while those of Chinese S. aspratus were 112.2±40.8 mg/kg, 297.8±20.9 mg/kg, 10,938.4±2,914.1 mg/kg, and 52.5±27.7 mg/kg, respectively. There were no significant differences in the micro mineral contents and hazardous heavy metal contents between domestic and Chinese S. aspratus, while there was a significant difference in the macro mineral contents between domestic and Chinese S. aspratus. Thus, the comparative analyses of the sodium, magnesium, potassium, and calcium contents of many domestic and Chinese S. aspratus are required to determine their production sites in the future.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.655-666
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• 2020

Objectives: The purpose of this study was to evaluate urinary arsenic concentrations by arsenic species and to identify related factors among local residents near abandoned metal mines in Korea. Methods: Among the subjects of the Health Survey of Residents Near Abandoned Metal Mines for 2013-2017, 664 people were enrolled in this study. Urinary arsenic species analysis was performed using ICP/MS. Result: The geometric means (95% Confidence Interval) by urinary arsenic species were 0.15 (0.13-0.17) ㎍/L for AsIII, 0.64 (0.55-0.75) ㎍/L for AsV, and 1.21 (1.05-1.40) ㎍/L for inorganic arsenic. The geometric means of urinary MMA and DMA were 1.58 (1.35-1.86) ㎍/L and 77.93 (72.61-83.63) ㎍/L, respectively, and that of organic arsenic was 83.15 (77.80-88.88) ㎍/L. The concentration of inorganic arsenic in the group using groundwater as drinking water was 1.36 (1.13-1.64) ㎍/L, which was statistically significantly higher than the 1.00 (0.80-1.25) ㎍/L in the other drinking water groups. Regarding rice consumption, the concentration of inorganic arsenic in urine in the group whose consumption was more than half rice produced in the residential area was 1.32 ㎍/L, which was statistically significantly higher than that of the 1.12 ㎍/L for the group whose consumption was less than half. Conclusion: In the analysis of the factors affecting the urinary inorganic arsenic concentration of the residents of the abandoned metal mine area, the use of groundwater as drinking water and consumption of rice produced in the residential area were considered related factors.

• Clean Technology
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• v.26 no.4
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• pp.270-278
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• 2020

Palladium (Pd) has been widely used in various industrial applications such as jewelry, catalyst, and dental materials despite its limited resources. It has been gaining attention to recover Pd with high purity from the spent materials. This study investigated the optimum conditions for the leaching and recovery of metallic Pd. The leaching parameters are HCl concentration, temperature, time, concentration of oxidants, and pulp density. 97.2% of Pd leaching efficiency was obtained in 3 M HCl with 3 vol% oxidants at 80℃ for 60 min. The ratio of hydrogen peroxide to sodium hypochlorite played a critical role in the leaching efficiency due to the supply of Cl- ions in the leachate. Moreover, the complete recovery of Pd in the leachate was achieved at 80℃ with 0.3 formic acid/leachate after adjusting the pH value of 7. This situation was ascribed to the decomposition of formic acid into hydrogen gas and carbon dioxide at 80℃. ICP-AES and XRD characterized the recovered Pd powder, and the purity of the recovered powder was found to be 99.6%. Consequently, the recovered Pd powder with high purity could be used in circuits, catalyst precursors, and surgical instruments.

• Journal of the Korean earth science society
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• v.42 no.1
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• pp.1-10
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• 2021

Silicon (Si) is the second most abundant element in the crust and consists of three stable isotopes, 28Si (92.23%), 29Si (4.67%), and 30Si (3.10%). Si isotopes are widely studied worldwide as a proxy for the biogeochemical cycle of Si to reconstruct the paleoenvironment and paleoclimate. However, in Korea, there have been no studies on biogenic silica using Si isotopes. In this study, we carried out Si isotope measurements of giant diatoms, summarizing the previously reported alkali fusion methods and establishing the best Si separation method for biogenic silica. Samples were completely digested using alkali fusion at high temperatures, effectively separating Si using an AG® 50W-X8 cation exchange resin. To evaluate the precision and accuracy of our measurements, Si isotope standard material (NBS-28) and USGS reference materials (AGV-2, GSP-2, BHVO-2) were analyzed. The results are in excellent agreement with the reported values within the acceptable error. The Si isotope measurement method developed in this study is expected to help in understanding the paleoclimate and paleoenvironment by tracing the Si cycle.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.530-539
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• 2021

Background: In South Korea, areas around abandoned metal mines are designated as regions with high arsenic (As) contamination. However, studies assessing urinary As exposure, As metabolism, and relevant genetic polymorphisms in residents of these metal mine areas are lacking. Objectives: To identify factors associated with As exposure and evaluate the effects of MTHFR, As3MT, and GSTO1 genetic polymorphisms on As metabolism in residents of abandoned metal mine areas by measuring urinary As species. Methods: Urinary As species (arsenite [As³⁺], arsenate [As⁵⁺], monomethyl arsonic acid, and dimethylarsinic acid) were isolated using high-performance liquid chromatography in combination with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Four genetic polymorphisms (MTHFR A222V, MTHFR E429A, GSTO1 A140D, As3MT M287T) were analyzed in 144 residents of four areas around abandoned metal mines. Results: The study sample was comprised of 34.7% men and 65.3% women, with a mean age of 70.7±10.9 years. The urinary inorganic As concentration was higher among those consuming more than half locally produced rice (0.31 ㎍/L) than those consuming less than half such rice (0.18 ㎍/L). The urinary dimethylarsinic acid concentration was higher in the group that had consumed seafood in the past day (31.68 ㎍/L) than in those who had not (22.37 ㎍/L). Furthermore, individuals heterozygous in the MTHFR A222V and GSTO1 A140D polymorphism had higher urinary arsenic species concentrations than did individuals with a wild type or homozygous for the variant allele. Conclusions: Consumption of locally produced rice was associated with inorganic As exposure, whereas seafood consumption was associated with organic As exposure among residents of abandoned metal mine areas. There was no clear association between MTHFR A222V and GSTO1 A140D polymorphisms and As metabolism.

• Korean Journal of Community Nutrition
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• v.27 no.3
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• pp.245-253
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• 2022

Objectives: This study was conducted to find out if the dietary iron intake of Koreans estimated by 2 different methods (iron content sources) using the food intake data from the Korea National Health and Nutrition Examination Survey (KNHANES) are comparable. One method was based on the KNHANES's Food & Nutrient Database (FND) derived mainly from the Korean Food Composition Table and the other used the iron content (IC) of food samples processed in the Korean Total Diet Study (KTDS). Methods: Dietary intake data from the 2013-2016 KNHANES was used to select representative foods (RFs) in KTDS for iron analysis. Selection of the RFs and cooking methods for each RF (RF × cooking method pair) was performed according to the 'Guidebook for Korean Total Diet Studies' and resulted in a total of 132 RFs and 224 'RF × cooking method' pairs. RFs were collected in 9 metropolitan cities nationwide once or twice (for those with seasonality) in 2018 and made into 6 composites each, based on the origin and season prior to cooking. Then, the RF composites prepared to a 'table ready' state for KTDS were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Dietary iron intake of the Korean population was estimated using only RFs' intake data based on the 2 sources of iron content, namely FND-KNHANES and IC-KTDS. Results: RFs in KTDS covered 92.0% of total food intake of Koreans in the 2016-2018 KNHANES. Mean iron intake of Koreans was 7.77 mg/person/day by IC-KTDS vs 9.73 mg/person/day by FND-KNHANES. The major food groups contributing to iron intake were meats (21.7%), vegetables (20.5%), and grains & cereals (13.4%) as per IC-KTDS. On the other hand, the latter source (FND-KNHANES) resulted in a very different profile: grains & cereals (31.1%), vegetables (16.8%), and meats (15.3%). While the top iron source was beef, accounting for 8.6% in the former, it was polished rice (19.2%) in the latter. There was a 10-fold difference in the iron content of polished rice between 2 sources that iron intakes excluding the contribution by polished rice resulted in very similar values: 7.58 mg/person/day by IC-KTDS and 7.86 mg/person/day by FND-KNHANES. Conclusions: This study revealed that the dietary iron intake estimated by 2 different methods were quite comparable, excluding one RF, namely polished rice. KTDS was thus proven to be a useful tool in estimating a 'closer-to-real' dietary intake of nutrients for Koreans and further research on various nutrients is warranted.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.457-462
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• 2022

Manganese (Mn) exists in various oxidation states and Mn(II) is the most mobile species of Mn, which is toxic to plants and limits their growth. Therefore, the purpose of this study was to reduce Mn toxicity by immobilizing Mn using various adsorbents including iron oxides and calcium compounds. Ferrihydrite, schwertmannite, goethite were synthesized, which was confirmed by X-ray diffraction. Hematite was purchased and used as Mn adsorbent. Calcium compounds such as CaNO₃, CaSO₄, and CaCO₃ were used to increase pH and oxidize Mn. For Mn adsorption, Mn(II) solution was reacted with four iron oxides, CaNO₃, CaSO₄, and CaCO₃ for 24 hours, filtered, and the remaining Mn concentrations in the solution were analyzed by inductively coupled plasma optical emission spectroscopy. The adsorption rate and adsorption isotherm were calculated. Among iron oxides, the adsorption rate was highest for hematite followed by ferrihyrite, but goethite and schwertmannite did not adsorb Mn. In the case of calcium compounds, the adsorption rate was high in the order of CaCO₃>CaNO₃>CaSO₄. In conclusion, treatment of CaCO₃ was the most effective in reducing Mn toxicity by increasing pH.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.2
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• pp.119-125
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• 2021

⁸²Sr for ⁸²Rb generator was produced through the irradiation of the proton beam on the ^nat.RbCI target at the target irradiation facility installed at the end of the Rl-dedicated beamline of the 100 MeV proton linear accelerator of KOMAC (Korea Multi-purpose Accelerator Complex). The average current of the proton beam was 1.2 µA for irradiation time of 150 min. For the separation and purification of the ⁸²Sr from ^nat.RbCI irradiated, Chelex-100 resin was used. The activities of ⁸²Sr in the irradiated ^nat.RbCI target solution and after purification were 45.29 µCi and 43.4 µCi, respectively. The separation and purification yield was 95.8%. As an adsorbent to be filled in the generator for ⁸²Sr adsorption hydrous tin oxide was selected. The adsorption yield of ⁸²Sr into the generator adsorbent was > 99 %, and the total amount of ⁸²Sr adsorbed to the generator was 21.6 µCi as of the day of the ⁸²Rb elution experiment. When the elution amount was 22 mL, the maximum⁸²Rb elution yield was 93.3%, and the elution yield increased as the flow rate increased. After the eluted ⁸²Rb was filled in the correction phantom of the small PET for animals, a PET image was taken. The image scan time was set to 5 min, and the phantom PET image was successfully obtained. As results of impurity analysis on eluted ⁸²Rb using ICP-MS, ^nat.Rb stable isotopes that compete in vivo of ⁸²Rb were identified as undetected levels and were determined to be No-Carrier-Added (NCA).

• Economic and Environmental Geology
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• v.56 no.4
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• pp.409-419
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• 2023

Acid mine drainage(AMD) treatment is classified as both passive and active treatment. During the treatment, about 5,000 tons of neutralization sludge is generated as a by-product per year in Korea. This study was conducted to evaluate the characteristics of sludge generated from physico·chemical treatment processes as an active treatment from 5 different sources (D, H, S, T, Y) and the possibility of the sludges being recycled. The sludges have a pH range of 5.86 ~ pH 7.89, and a water content range of 51% ~ 82%. Most of particle sizes were less than 25 ㎛. In analysis of inorganic elements, the concentration of Al, Fe, and Mn were between 1,189 mg/kg ~ 129,344 mg/kg, 106,132 mg/kg ~ 338,011 mg/kg, and 3,472 mg/kg ~ 11,743 mg/kg, respectively. The concentration of As and Zn in sludge-T, Cd in sludge-D, Ni in sludge-H, Zn in sludge-S, and Cd in sludge-Y exceeded the soil contamination standards of Korea. The results from 2 separate kinds of leaching test, the Korea Standard Leaching Test(KSLT) and Toxicity Characteristic Leaching Procedure(TCLP), showed that all the sludges met the Korea groundwater standards. From the XRD and SEM-EDS analysis, the peaks of calcite and quartz were found in the sludges. The sludge also had a high proportion of Fe and O, and the majority of the composition was amorphous iron hydroxide.

• The Korea Journal of Herbology
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• v.38 no.5
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• pp.85-95
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• 2023

Objectives : This study was intended to reveal the chemical profiles of aerial(leaf, stem) and underground(rhizome, radix) parts of wild ginseng, and to investigate their anti-aging effects on human skin cells. Methods : Wild ginseng, estimated for over 20 years, was divided into the aerial and underground parts. Total phenolic contents of each extracts were measured using a Folin-ciocalteu method. The contents of 18 amino acids, 8 minerals and 27 ginsenosides were determined by GC-FID, ICP-MS and LC-MS, respectively. The anti-aging effects, including the radical scavenging activity, the activation of mitochondrial function on human fibroblasts, and the proliferation activity on human keratinocyte progenitor cells, for the whole plant and underground part of wild ginseng were evaluated. Results : The total phenolic acids, amino acids, and minerals in the aerial part were more than twice as high as in the underground part. Compared to the cultivated ginseng root, there were various types of ginsenosides in both parts of wild ginseng, and the total amount was more than twice as high. In particular, the aerial part significantly contained ginsenoside F1, F2, C-Mc1, and C-O, and the distinctive patterns that distinguish each parts of wild ginseng from the cultivated ginseng root were derived. The whole plant and underground part of wild ginseng exhibited significant antioxidant effect(14.3-45.6%), activation of mitochondrial membrane potential(105.5-120.1%), and cell proliferation(112.1-125.4%). Conclusions : The entire plant and underground part of wild ginseng are high value-added plants and have beneficial effects on skin anti-aging properties through its abundant metabolites.