• Applied Biological Chemistry
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• v.48 no.3
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• pp.292-295
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• 2005

Synthesis of methyl 3-methyloctanoate, a perfume component isolated from African orchid Aerangis confusa (or Aerangis kirkii) was achieved starting from itaconic acid in 9 steps. Itaconic acid is one of the cheapest organic compounds which is the fermentation product of microorganism Asp. terreus. As the key intermediate, 2-methyl-1,4-butanediol 4-acetate was obtained through the enzymatic regioselective hydrolysis of 2-methyl-1,4-butanediol diacetate with lipase. After Grignard reaction and oxidation, 3-methyloctanoic acid was obtained and converted to the various corresponding scented esters with a variety of alkyl alcohols, and the resulting fragrancy esters are expected to be utilized as the aroma additive materials in cosmetics, drinks and foods.

• Journal of Korean Elementary Science Education
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• v.40 no.1
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• pp.13-21
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• 2021

This study analyzed the effects of 'online biology learning using E-learning system' on elementary school students' science-related attitudes. Samples of the study were composed of 95 sixth-grade students of N elementary school in Seoul, Korea. The learning was conducted for 11 times over a month. The main results of this study are as follows. First, for the paired t-test, a statistically significant difference between the pre and post scores of science-related attitudes was found. After conducting the online biology learning science related attitudes scores of students generally declined. "The boredom caused by simply watching online biology contents" is the decisive cause of the decline in science-related attitude scores analyzed through interviews. Second, in ANCOVA, according to 'levels of meta-cognition'. there was no statistically significant difference in scores of science-related attitudes. but, there was statistically significant difference in science-related attitudes according to 'adoption of scientific attitudes'. Students of high meta-cognition type showed a greater decline in scores than students of low meta-cognition type. Based on the results of this study, implications for research of online biology education and elementary science education are discussed.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.167-179
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• 1994

Recent evidence indicates that glial cells have a wide range of funtions which are critical for maintaining a balanced homeostatic environment in the central nervous system(CNS) peripheral nervous system(PNS). Morever, astrocytes are known to participate in the tissue repair and neuroimmunologic events within the CNS through many kinds of growth factors and cytokines. We investigated the effect of $TGF\;{\beta}_1$, on the growth and biochemical changes of rat glial cells in culture. The proliferative effect was determined by $^3H-thymidine$ uptake and the double immunostain with anti-cell-specific marker and anti-Bromodeoxyuridine(BrdU) antibody. To check the effect of biochemical changes we compared the amounts of glial fibrillar acidic protein(GFAP) and the activity of glutamine synthetase(GS) in astrocyte. And the amounts of myelin basic protein and the activity of 2',3'-cyclic nucleotide phosphohydrolase(CNPase) were measured in oligodendrocyte and the amounts of peripheral myelin in Schwann cell. When $TGF\;{\beta}_1$, was treated for 2 days with cultured glial cell, $TGF\;{\beta}_1$, decreased the $^3H-thymidine$ uptake and proliferation index of double immunostain of astrocytes, which indicates the inhibition of astroglial DNA synthesis, but stimulated the growth of Schwann cell. Also, $TGF\;{\beta}_1$, decrease the GS activity and increased the amounts of GFAP in astrocyte. In the case of Schwann cells the amounts of peripheral myelin was increased when treated with $TGF\;{\beta}_1$. However, $TGF\;{\beta}_1$, didn't show any effect on the proliferation and biochemical changes in oligodendrocyte. These results suggest that $TGF\;{\beta}_1$, might have a critical action in the regulation of proliferation and biochemical changes in glial cells, especially astrocyte.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.131-138
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• 2018

PURPOSE: This study was conducted to compare the muscle activity of the proximal muscles of the lower limb according to the distance between the front and rear foot during lunge and to determine the most effective foot position for activation of the proximal muscle in the limb. METHODS: A total of 49 young adults were enrolled in this study. All subjects performed lunge by positioning the big toe of the back foot and the heel of the front foot at intervals of 40%, 60%, and 80% of the subject's own leg length. Muscle activity of the vastus medialis oblique, rectus femoris (RF), vastus lateralis oblique (VLO), gluteus medius, biceps femoris, and semitendinosus (ST) was then measured during three intervals of lunge operation. Each operation was measured three times for 10 seconds each, after which the average value was calculated and analyzed. RESULTS: There were significant differences in muscle activities of RF, VLO, and ST among the three intervals of the foot (p<.05). Post hoc, comparisons revealed lunge at 40% intervals resulted in higher RF and VLO activity than at 60% and 80% intervals (p<.05). In the semitendinosus muscle, 80% leg length intervals showed higher muscle activity than 40% (p<.05). CONCLUSION: Strengthening of the proximal muscles of the lower extremities during lunge exercise is considered to be most effective when placing the fore- and rear foot at intervals corresponding to 40% of the leg length.

• Journal of Korean Elementary Science Education
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• v.40 no.4
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• pp.545-555
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• 2021

This study aims to analyze research trends by the period of elementary science education journal. A total of 1047 papers were analyzed from Volume 1 No. 1 in 1983 to Volume 39 No. 4 in 2020. The results of the study are as follows: First, the period of elementary science education journals was divided into infancy, settlement, development, and retainment period according to the number of papers. Second, the ratio of research by more than three scholars, pure or funded research was decreasing. Third, the study subjects had a high rate of research on elementary school students and elementary school teachers. Fourth, research methods were mainly research studies and experimental studies, and qualitative analysis and mixed analysis studies were increasing as data analysis methods. Fifth, the occupation of the first author was professor (45.6%), teacher (39.8%), graduate student (10.6%), and researcher (1.7%) in that order. Sixth, the regions of the corresponding author were concentrated in Seoul and Gyeongin, the metropolitan areas. Finally, in order for the "Elementary Science Education" journal to continue to play a pivotal role in leading elementary science education in the future, efforts to improve the overall journal and continuous participation and cooperation of domestic and foreign researchers, academic executives, members, and educational institutions are required.