• Applied Microscopy
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• v.33 no.2
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• pp.105-116
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• 2003

In Vitro fertilization of U. unicinctus eggs observed by immunofluorescence and electron microscopes revealed an overview of the meiotic pattern of the tide animals. The eggs have been fertilized early at germinal vesicle stage, followed by germinal vesicle break down (GVBD), but pre-mitotic aster like structure could not be resolved by the methods employed in this work. The meiotic features, such as rotation-shift movement of spindle fibers, behavior of spermatozoonmonaster in the egg cytoplasm and active spindle fiber of the 1st polar body, have been observed. The antitubulin-FITC fluorescence show the 2nd meiotic apparatus appeared firstly parallel to the tangential line of the oolemma, proceeding the meiosis, its bipolarity is rotated and shifted towards the oolemma. The polar bodysite of the oolemma was not amorphous, but active in a sense of anti-tubulin-FITC reactions during the extrusions of the polar bodies. The immunofluorescence reactions of the spermatozoon centriole appeared at a later stage of the 2nd meiosis. During the time periods, the fertilized spermatozoon resided in the egg cytoplasm. Activating the centrioles, spermatozoon approaches towards the chromosomal materials of the 2nd oocyte. This suggests that spermatozoon centrioles initiate and play a roll to fuse male and female pronuclei.

• Journal of Radiation Protection and Research
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• v.23 no.3
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• pp.159-174
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• 1998

Personal dosimetry system is required to measure the personal dose equivalent accurately in a wide range of radiation fields, but the dose evaluation algorithms have been developed with the X-ray fields described in MOST Ordinance (equivalent to the ANSI N13.11) from which the actual fields to be monitored may be significantly different. To evaluate the dose more accurately when workers are exposed to the non-ANSI N13.11 radiation fields, two algorithms for monochromatic radiations (one algorithm was used for various ratios of TL dosimeter and the other for matrix approximation) were developed with the experimental data of the energy responses of the $CaSO_4:Dy$ TL materials irradiated by monochromatic X-ray fields recently established in KAERI, and compared with the another algorithm developed on the basis of the ANSI N13.11 continuous spectrum X-ray fields. Then it follows the discussions for some results of the algorithm testing including mixed fields irradiations and angular response conducted in IAEA/RCA intercomparison as well as ANSI and ISO continuous spectrum X-ray and monochromatic radiation fields. The developed algorithms were successfully performed the test not only in the continuous spectrum X-ray fields given by MOST Ordinance but also in the several non-MOST Ordinance radiation fields which could be encountered in the practical working environments.

• Journal of Genetic Medicine
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• v.12 no.1
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• pp.38-43
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• 2015

Purpose: Spinocerebellar ataxias (SCAs) are progressive neurodegenerative disorders with diverse modes of inheritance. There are several subtypes of SCAs. SCA 8, SCA 12, and SCA 17 are the less common forms of SCAs with limited information available on their epidemiological profiles in Korea. The purpose of this study was to investigate the prevalence of SCA8, SCA12, and SCA17 in Korea. Materials and Methods: Ninety-six unrelated Korean patients were enrolled and showed normal trinucleotide repeats through polymerase-chain reaction (PCR) for the genes ATXN1, ATXN2, ATXN3, CACNA1A, and ATXN7, which correspond to SCA1, SCA2, SCA3, SCA6, and SCA7, respectively. PCR products from patients were further analyzed by capillary electrophoresis using fluorescence labeled primers for the genes ATXN8OS, PPP2R2B, and TBP, which correspond to SCA8, SCA12, and SCA17. Results: Three patients had 104, 97, and 75 abnormal expanded repeats in the ATXN8OS gene, the causative gene for SCA8. None of the patients exhibited abnormal repeats in SCA12 and SCA17. Normal trinucleotide repeat ranges of the cohort in this study were estimated to be 17-34 copies (average, $24{\pm}4copies$) for SCA8, 7-18 copies (average, $13{\pm}3copies$) for SCA12, and 26-43 copies (average, $35{\pm}2copies$) for SCA17. Conclusion: This study demonstrated that SCA8, SCA12, and SCA17 are rare in Korean patients with SCA, and further genetic studies are warranted to enhance the mutation detection rate in the Korean SCA population.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1229-1234
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• 2007

Antioxidant activities of extracts from anglerfish (Lophiiu Zitulon) were evaluated. Each part of fresh (skin, flesh, stomach, and liver) or dried (skin and flesh) anglerfish was extracted by four different solvents (methanol, ethanol, acetone, and distilled water). Antioxidant activities of the extracts were determined by radical scavenging activity (RSA) and reducing power (RP). Relatively higher RSA and RP were found in methanol and water extract of fresh anglerfish liver. Antigenotoxic effect of the extracts, which was measured by Comet assay, was shown in most of the extracts except methanol, acetone and distilled water extracts of fresh stomach sample. These results indicated that antioxidant and antigenotoxic properties of extracts from angler fish were variable depending on parts, solvent, and/or physicochemical state. The appropriate extraction process could provide some valuable bioactive materials from anglerfish.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.1-12
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• 1978

This study has intended to disclose the change of some chemical compositions of Ginkgo seeds which were acquired the treatment of cold-moist-stratification after collection. As check sample, the room-stored seeds were used. With the reasons that when the seeds not stratified were sown the delay of field germination has usually been resulted, the effectiveness of stratificaation in respect to alteration of chemical composition is to be investigated. The increase and decrease of growth promoting and inhibiting substances were investigated by means of chromatography method followed by rice seedling test or wheat coleoptile straight-growth test. The results obtained are summarized as follows; 1. In the untreated seeds, the zone of growth inhibitors on paper chromatograph were observed without regard to the tissue differences, embryo, endosperm and seedcoat. 2. Due to stratification, the amount of inhibitor has decreased in the embryo and seed coat, but growth promoters was decreased as compared with the check materials 3. The indications of results appear that each portion of the embryo, endosperm, and seedcoats of Ginkgo biloba L. contains the growth in hibitor taking part in germination dormancy. 4. It was presumed that hastening germination was influenced by decreasing of inhibitors in the embryo and seed coats rather than by increasing of promoters. 5. Gibberellin was detected at Rf 0.26 under the UV-lamp and the abscisic acid was detected at Rf 0.62, Rf 0.70, and Rf 0.78 and showed purple, gray, blue fluorescence respectively under the UV-lamp.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.5
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• pp.285-295
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• 1999

Electroluminescent(EL) devices based on organic materials have been of great interest due to their possible applications for large-area flat-panel displays. They are attractive because of their capability of multi-color emission, and low operation voltage. An approach to realize such device characteristics is to use active layers of lanthanide complexes with their inherent extremely sharp emission bands in stead of commonly known organic dyes. In general, organic molecular compounds show emission due to their $\pi$-$\pi*$ transitions resulting in luminescence bandwidths of about 80 to 100nm. Spin statistic estimations lead to an internal quantum efficiency of dye-based EL devices limited to 25%. On the contrary, the fluorescence of lanthanide complexes is based on an intramolecular energy transfer from the triplet of the organic ligand to the 4f energy states of the ion. Therefore, theoretical internal quantum efficiency is principally not limited. In this study, Powders of TPD, $Eu(TTA)_3(phen) and AlQ_3$ in a boat were subsequently heated to their sublimation temperatures to obtain the growth rates of 0.2~0.3nm/s. Organic electrolumnescent devices(OELD) with a structure of $glass substrate/ITO/Eu(TTA)_3(phen)/AI, glass substrate/ITO/TPD/Eu(TTA)_3(phen)/AI and glass substrate/ITO/TPD/Eu(TTA)_3(phen)/AIQ_3AI$ structures were fabricated by vacuum evaporation method, where aromatic diamine(TPD) was used as a hole transporting material, $Eu(TTA)_3(phen)$ as an emitting material, and Tris(8-hydroxyquinoline)Aluminum$(AlQ_3)$ as an electron transporting layer. Electroluminescent(EL) and current density-voltage(J-V) characteristics of these OELDs with various thickness of $Eu(TTA)_3(phen)$ layer were investigated. The triple-layer structure devices show the red EL spectrum at the wavelength of 613nm, which is almost the same as the photoluminescent(PL) spectrum of $Eu(TTA)_3(phen)$.It was found from the J-V characteristics of these devices that the current density is not dependent on the applied field, but on the electric field.

• Korean Journal of Optics and Photonics
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• v.9 no.4
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• pp.221-226
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• 1998

Ternary heavy metal oxide glasses in the $PbO-Bi_2O_3-Ga_2O_3$ system doped with $Er_2O_3$ were prepared and their spectroscopic properties, such as radiative transition probability, calculated and measured radiative lifetimes and cross-sections of 1.5 $\mu\textrm{m}$ and 2.7 $\mu\textrm{m}$ emissions were analyzed. Enhanced quantum efficiencies of some electronic transitions were evident mainly because of the low vibrational phonon energy ($~500cm^{-1}$) inherent in the host glasses. This seems to be the main reason for obtaining the 2.7 $\mu\textrm{m}$ luminescence which is normally quenched in the conventional oxide glasses. In addition, green and red fluorescence emissions were observed through the frequency upconversion processes of the 798 nm excitation. Non-radiative transition due to the multiphonon relaxation is a dominant lifetime-shortening mechanism in the 4f-4f transitions in $Er^{3+}$ ion except for the $^4S_{3/2}{\rightarrow}^4I_{15/2}$ transition where a non-radiative transfer to band-gap excitation of the host glasses is dominant. Melting of glasses under an inert gas atmosphere and (or) addition of the typical glass-network former into glasses is necessary in order to enhance the quantum efficiency of the transition.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.245-257
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• 2016

Although rivers cover only 0.5% of the total land area on the Earth, they are windows that show the integrated effects of watershed biogeochemistry. Studies on the loads and properties of riverine carbon have been conducted because they are directly linked with drinking water quality, and because regional or global net ecosystem production (NEP) can be overestimated, unless riverine carbon loads are subtracted. Globally, ${\sim}0.8-1.5Pg\;yr^{-1}$ and ${\sim}0.62-2.1Pg\;yr^{-1}$ of carbon are transported from terrestrial ecosystems to the ocean via rivers and from inland waters to the atmosphere, respectively. Concentrations, ${\delta}^{13}C$, and fluorescence spectra of riverine carbon have been investigated in South Korea to understand the spatiotemporal changes in the sources. Precipitation as well as land use/land cover can strongly influence the composition of riverine carbon, thus shifting the ratios among DIC, DOC, and POC, which could affect the concentrations, loads, and the degradability of adsorbed organic and inorganic toxic materials. A variety of analyses including $^{14}C$ and high resolution mass spectroscopy need to be employed to precisely define the sources and to quantify the degradability of riverine carbon. Long-term data on concentrations of major ions including alkalinity and daily discharge have been used to show direct evidence of ecosystem changes in the US. The current database managed by the Korean government could be improved further by integrating the data collected by individual researchers, and by adding the major components ions including DIC, DOC, and POC into the database.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.710-718
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• 2017

Contents of water soluble vitamin $B_6$ in a total of 62 agricultural products cultivated in local areas in Korea were analyzed by high performance liquid chromatography with fluorescence detector (HPLC/FLD). To verify the method of vitamin $B_6$ analysis, a quality control chart was formulated with in-house control using a mixture of broccoli and shiitake mushrooms. Among cereals, high content of vitamin $B_6$ measured $234.3{\sim}260.3{\mu}g/100g$ in dried mung bean and soybean. Vitamin $B_6$ content of non-glutinous and glutinous black rice measured $105.0{\mu}g/100g$ and $129.7{\mu}g/100g$, respectively. In vegetables, high content of vitamin $B_6$ were measured in passion fruit ($104.3{\mu}g/100g$), gat ($55.7{\sim}84.3{\mu}g/100g$), gomchwi ($31.3{\sim}88.0{\mu}g/100g$) and garlic ($72.7{\sim}98.3{\mu}g/100g$). Among fruits, gold kiwi 'Zespri' and green kiwi 'Hayward' revealed high vitamin $B_6$ content of $116.3{\mu}g/100g$ and $78.7{\mu}g/100g$, respectively. In persimmons, daebongsi had high vitamin $B_6$ content ($36.0{\sim}72.7{\mu}g/100g$) than bansi and sweet persimmon. Vitamin $B_6$ content in dried jujube and persimmon increased more than $86.7{\mu}g/100g$ compared to fresh materials. Among specialty crops, green tea powder ($64.7{\sim}251.0{\mu}g/100g$) and sansuyu ($172.3{\mu}g/100g$) revealed high content. Of mushrooms, vitamin $B_6$ content of Sparassis crispa ($139.3{\mu}g/100g$) was the highest. Vitamin $B_6$ content information of agricultural products in local areas in Korea collected from this experiment will be used as valuable preliminary data for grasp national nutritional status.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.293-300
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• 2019

As a common side effect of fixed orthodontic treatment, demineralization of the enamel adjacent to the bracket and band occurs in patients with poor oral hygiene. The purpose of this study was to investigate what is the most effective method to prevent demineralization around the fixed orthodontic appliance among various methods using fluoride. 80 extracted bovine incisors with a healthy surface were classified into four groups as experimental materials: (Group I) Control group, (Group II) V $varnish^{TM}$, (Group III) Tooth Mousse $Plus^{(R)}$, (Group IV) $Vanish^{TM}$ XT. After treatment for each group, mineral loss and Vickers surface microhardness were measured at 0, 30, 60 and 90 days after demineralization in artificial carious solution. Mineral loss was the lowest in group IV, followed by group II and group III, which showed a significant difference. The surface microhardness was the lowest in group IV, followed by group II and group III, which showed a significant difference. Through this study, group IV showed the best effect to prevent enamel demineralization around the bracket. Group III showed significant prevention of enamel demineralization compared with the control group, but the effect was less than that of the other groups.