• Applied Biological Chemistry
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• v.22 no.4
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• pp.221-226
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• 1979

The soils and plants were sampled from 26 sites of Deogpyeongri, Goisangun, which had been found to be one of the uranium deposit areas. Uranium levels of the samples were determined and the amount of uranium intake by the residents through the food-chains was estimated. The average uranium concentration of Deogpyeongri soils was 15.5ppm with a range of from 4.9 to 43.6ppm showing rather higher values than those of control area, Yangjugun and Icheongun, Gyeonggi-do. The average uranium content of the plant samples from Deogpyeongri was 0.69ppm, about twice the uranium concentration of the control samples. The daily intake of uranium by an adult lived on the agricultural food stuffs produced in Deogpyeongri, was estimated to be about $247{\mu}g$, eqivalent to $0.83{\times}10^{-4}{\mu}Ci$, which is much higher activity compared to the daily intake of uranium by New York citizen, $1.3{\mu}g$. However the calculated uranium level accumulated in the human body of Deogpyeong area was $2.03{\times}10^{-4}{\mu}Ci$ which is still lower than $0.2{\mu}Ci$, the maximum permissible burden in total body recommended by the ICRP.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.41-44
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• 2002

During the phloem development from parenchyma cells in a suspension culture of Streptanthus induced sucrose carrier and glucose carrier disappeared. Sieve element area and sieve pore induced suspension culture of Streptanthus were formed almost at the last period of the synthesis of sieve endoplasmic reticulum (SER) and p-protein. The new synthesized cell wall begann to digeste only after the new cell wall was surrounded by SER. The digested region of the cell wall and the formed region of sieve pore were regular comparatively. The completed sieve pore was an oval form, and the outer portion of sieve pore varied, ca 1.2 ${\mu}{\textrm}{m}$~1.6 ${\mu}{\textrm}{m}$ in longitudinal, 0.8 ${\mu}{\textrm}{m}$~1.3 ${\mu}{\textrm}{m}$ in tangential, and the inner size of sieve pore was irregular form of a star-like shape. The number of sieve pore between sieve cells was ca 2~7 per ${\mu}{\textrm}{m}$$^2$ and the sieve pore wall with callose was 0.05 ${\mu}{\textrm}{m}$~0.07 ${\mu}{\textrm}{m}$ in thickness. The energy for the formation of sieve element area and sieve pore might be supplied by mitochondria near the new cell wall and the role of SER remains to be illucidated.

• Journal of Nutrition and Health
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• v.38 no.7
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• pp.544-552
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• 2005

This study was conducted to examine the correlation among bone mineral density (BMD), hair and nail calcium and magnesium contents, and nutrient intakes in preschool children in Chungnam district. A total of 111 preschool children (61 boys, 50 girls) measured the anthropometric characteristics, the bone mineral density of carpus using DEXA and hair and nail calcium and magnesium contents were analyzed by ICP spectrometer. The average ages of the study subjects were 55.7 months in boys and 53.0 months in girls (3.8${\~}$7 years). The birth height and weight of subjects were 51.0 cm and 3.3 kg in boys and 50.3cm and 3.2kg in girls, respectively. The average height, weight, $\%$ body fat, and obesity index were 111.6 cm, 19.6 kg, $15.0\%,\;96.1\%$ in boys and 108.6 cm, 18.5 kg, $17.5\%,\;98.1\%$ in girls, respectively. The bone mineral density in carpus was $0.25 g/cm^2$ in boys and $0.24 g/cm^2$ in girls. The hair calcium and magnesium contents were 440.9 ppm, 16.4 ppm in boys and 373.2 ppm, 28.9 ppm in girls. The nail calcium and magnesium contents were 9.4 ppm, 2.1 ppm in boys and 10.4 ppm, 2.4 ppm in girls. The intakes of energy, calcium, iron, zinc, vitamin A. niacin, and vitamin C did not meet the Korean RDAs. The ultradis and average carpus BMD were positively correlated to the plant calcium intake (p < 0.05, p < 0.05). And the ultradis, distal, and average carpus BMD were positively correlated to the plant iron intake (p < 0.05, p < 0.05, p < 0.05). The average bone mineral density in the carpus was positively correlated to the nail magnesium content (p < 0.05). Therefore, more systematic studies to investigate the roles of iron and calcium intakes, nail magnesium content in bone development of preschool children were required.

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.162-170
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• 2000

This study quantified the effects of urban greenspace on microclimate amelioration and atmospheric $CO_2$ reduction for several residential districts selected in Korea and Japan. The study also explored fire obstruction by urban trees to develop systematic planting guidelines. Transpiration by a Zelkova serrata tree (diameter at breast height: 15 cm) in a day of August equaled cooling effect of about 3 air conditioners running for 12 hours. Average air temperature for the growing season was 0.5$^{\circ}C$ and 1.2$^{\circ}C$ cooler, respectively, in districts with 12% and 22% cover of woody plants than in a district with no vegetation. Annual $CO_2$ uptake and $O_2$ production by woody plants were 3 times greater in a district which was 2 times higher in their cover. Woody plants played, in a district with their 22% cover, an important role through offsetting total $CO_2$ emission from the district by about 3% annually, and through producing 10% of annual $O_2$ requirement by all residents within the district. Appropriate planning strategies of residential greenspace, including species selection, planting layout, greenspace enlargement, and maintenance were suggested to improve microclimate amelioration, air purification, and fire obstruction.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.341-357
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• 2019

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hotspring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.2
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• pp.97-109
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• 2019

Degree days have been determined using temperature data measured at nearby weather stations to a site of interest to produce information for supporting decision-making on agricultural production. Alternatively, the data products of Moderate Resolution Imaging Spectroradiometer (MODIS) can be used for estimation of degree days in a given region, e.g., Korean Peninsula. The objective of this study was to develop a simple tool for processing the MODIS product for estimating cooling degree days (CDD), which would help assessment of heat stress conditions for a crop as well as energy requirement for greenhouses. A set of scripts written in R was implemented to obtain temperature profile data for the region of interest. These scripts had functionalities for processing spatial data, which include reprojection, mosaicking, and cropping. A module to extract air temperature at the surface pressure level was also developed using R extension packages such as rgdal and RcppArmadillo. Random forest (RF) models, which estimate mean temperature and CDD with a different set of MODIS data, were trained at 34 sites in South Korea during 2009 - 2018. Then, the values of CDD were calculated over Korean peninsula during the same period using those RF models. It was found that the CDD estimates using the MODIS data explained >74% of the variation in the CDD measurements at the weather stations in North Korea as well as South Korea. These results indicate that temperature data derived from the MODIS atmospheric products would be useful for reliable estimation of CDD. Our results also suggest that the MODIS data can be used for preparation of weather input data for other temperature-based agro-ecological models such as growing degree days or chill units.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.413-416
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• 2019

Alstroemeria (Alstroemeriaceae) is one of the most important cut flowers in international market. Especially, characteristics like long vase-life, various colors, tolerance to low temperature and a low energy requirement during cultivation have stimulated this success. Because of its characteristics such as low multiplication rates, time-consuming process and high risk of carrying viral disease, in vitro propagation techniques based on rhizome meristems culture have been developing nowadays. The callus induction has various cultivation sites compared with the direct plant generation method, and if the callus is maintained well, the plant differentiation can be performed simultaneously while maintaining the callus, so that it can be used for mass proliferation. In this study, we tested various hormones and cultivars for efficient callus induction. As a result of culturing between the nodes and the internodes, the callus began to be formed after 8 weeks, and the calli incidence in the nodes was higher than that between the internodes. Also, in the comparison of 2,4-D and picloram, the callus incidence rate was up to 2 times higher in the medium treated with 2,4-D. Using these results, it is thought that it will help establish the system of mass propagation system of Alstroemeria and cultivate new varieties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.430-439
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• 2019

In this study, a nonlinear impact analysis was performed to evaluate the safety and damage of an eco-pillar debris barrier with a hollow cross-section, which was proposed to improve constructability and economic efficiency. The construction of concrete eco-pillar debris barriers has increased recently. However, there are no design standards concerning debris barriers in Korea, and it is difficult to find a study on performance evaluations in extreme environments. Thus, an analysis of an eco-pillar debris barrier was done using the rock impact speed, which was estimated from the debris flow velocity. The diameters of rocks were determined by ETAG 27. The impact position, angles, and rock diameter were considered as variables. A concrete nonlinear material model was applied, and the estimation of damage was done by ABAQUS software. As a result, the damage ratio was found to be less than 1.0 at rock diameters of 0.3 m and 0.5 m, but it was 1.39 when the diameter was 0.7 m. This study could be used as basic data on impact force in the design of the cross section of an eco-pillar debris barrier.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.1
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• pp.107-120
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• 2019

The decommissioning of one nuclear power plant in a multi-unit nuclear power plant (multi-unit NPP) site may pose radiation exposure risk to decommissioning workers. Thus, it is essentially required to evaluate the exposure dose of decommissioning workers of operating multi-unit NPPs nearby. The ENDOS program is a dose evaluation code developed by the Korea Atomic Energy Research Institute (KAERI). As two sub-programs of ENDOS, ENDOS-ATM to anticipate atmospheric transport and ENDOS-G to calculate exposure dose by gaseous radioactive effluents are used in this study. As a result, the annual maximum individual dose for decommissioning workers is estimated to be $2.31{\times}10^{-3}mSv{\cdot}y^{-1}$, which is insignificant compared with the effective dose limit of $1mSv{\cdot}y^{-1}$ for the public. Although it is revealed that the exposure dose of operating multi-unit NPPs does not result in a significant impact on decommissioning workers, closer examination of the effect of additional exposure due to actual demolition work is required. The calculation method of this study is expected to be utilized in the future for planned decommissioning projects in Korea. Because domestic NPPs are located in multi-unit sites, similar situations may occur.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.368-376
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• 2021

This study was to investigate the Taraxinic acid from Taraxacum coreanum on tyrosinase activity and melanogenesis. In B16BL6 cell, Taraxinic acid did not show cytotoxicity even at concentrations of up to 100 ㎍/mL. In addition, tyrosinase inhibitory activity and melanogenesis inhibitory activity were confirmed by stimulation with α-melanocyte stimulating hormone (α-MSH) in the presence of taraxinic acid. Taraxinic acid was added to cells at concentrations of 10, 50 and 100 ㎍/mL and treated for 48 hours to confirm tyrosinase inhibitory activity and melanin production. The tyrosinase inhibitory activity increased in proportion to the amount of the sample, and showed an inhibitory activity of about 54.5% at a concentration of 50 ㎍/mL. Melanin production decreased in proportion to the sample amount, and it was about 62.2% at the concentration of 10 ㎍/mL. From the above results, it was found that Taraxinic acid had higher tyrosinase activity and melanin synthesis inhibitory activity in melanocyte than arbutin. The results suggest that Taraxinic acid can be utilized in natural whitening cosmetics.