• Communications of Mathematical Education
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• v.25 no.2
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• pp.341-360
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• 2011

This paper deals with contents that Sang-Seol Lee contributed to the natural science in the 19th century Korea. Prof. Sung-Rae Park, the science historian, called Sang-Seol Lee Father of the Modern Mathematics education of Korea. Sang-Seol Lee wrote a manuscript Botany with a brush in late 19th century. Botany was transcribed from Science Primers: Botany (written by J. D. Hooker), which is translated into Chinese by Joseph Edkins in 1886. The existence of Sang-Seol Lee's book Botany was not known to Korean scientists before. In this paper, we study the contents of Botany and its original text. Also we analyze people's level of understanding Western sciences, especially botany at that time. In addition, we study authors of 16 Primers jar Western Knowledge. We study the contribution of mathematician Sang-Seol Lee to science education in the 19th century Korea.

• Journal of Ecology and Environment
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• v.41 no.4
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• pp.120-124
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• 2017

We report the species of medicinal plants collected in Khuvsgul and Khangai Mountain regions of Mongolia. Of the vascular plants that occur in the study region, a total of 280 medicinal plant species belonging to 164 genera from 51 families are reported. Of these, we collected voucher specimen for 123 species between June and August in the years 2015 and 2016. The families Asteraceae (46 species), Fabaceae (37 species), and Ranunculaceae (37 species) were represented most in the study area, while Astragalus (21 species), Taraxacum (20 species), and Potentilla (17 species) were the most common genera found.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.179-185
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• 2001

Nitrate grown cells of cyanobacterium Plectonema boryanum, transferred to nitrogen stress, evolved nitrogenase catalyzed $H_2$ under microaerophilic condition. Nitrogen ($N_2$) in gs phase, low light intensity, and reducing substances in incubation phase stimulated $N_2$fixation ($H_2\;evolution$). Cyanobacterium grew slowly under microaerobic condition with a low intracellular ammonia pool. Nitrogen sources (${NO_3}^-,{NH_4}^+,\;and\;CH_3NH_3$) inhibited nitrogenase and glutamine synthetase (GS) transferase activity, and methylamine behaved like an ammonical nitrogen source. Depletion of molybdenum (Mo) and addition of tungsten (W) in the incubation medium inhibited $H_2$ evolution, Cyanobacterium was able to take up nitrate and expressed nitrate reductase (NR) activity under microaerophilic condition at an extremely slow rate.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2211-2214
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• 2010

The whole plant of Euphorbia helioscopia is an important traditional Chinese medicine. Fom its BuOH soluble extract, one new lactam (1), three new terpenoids (2-4) including a new naturally occurring compound, and three known compounds were isolated. Their structures were identified by spectroscopic evidences. In particular, the absolute configurations of side chain of compounds 1 and 2 were determined using computational methods.

• Mycobiology
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• v.47 no.4
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• pp.401-407
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• 2019

Two new species of the lichen genus Placolecis are discovered in China, namely P. kunmingensis An. C. Yin & Li S. Wang and P. sublaevis An. C. Yin & Li S. Wang. The new combination P. loekoesiana (S.Y. Kondr., Farkas, J.J. Woo & Hur) An. C. Yin is proposed. Placolecis kunmingensis is characterized by having simple, spherical or ellipsoid, hyaline spores, and pear-shaped pycnidia; while P. sublaevis can be distinguished by its thallus forming larger aggregations with slightly flattened lobes at the thallus margin, and urn-shaped pycnidia. Descriptions, a phylogenetic tree and a key are provided for all the known Placolecis species in China.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.127-130
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• 2011

One new tirucallane-type triterpenoid, alianthusaltinin A (1), one new $C_{29}$ sterone, alianthaltone A (2), and 12 known compounds have been isolated from the stem bark of Ailanthus altissima. The structures of new compounds were identified by means of spectroscopic methods. Compound 3 was isolated from natural sources for the first time, and compounds 4, 5, and 9 were isolated from this plant for the first time.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2247-2250
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• 2012

Two new bibenzyl glucosides, 3,3',4',5-tetramethoxybibenzyl-4-O-${\beta}$-D-glucopyranoside (1) and 3,4,4',5-tetramethoxybibenzyl-3'-O-${\beta}$-D-glucopyranoside (2), together with five known ones, chrysotobibenzyl (3), erianin (4), chrysotoxine (5), gigantol (6) and tristin (7) were isolated from the stems of Dendrobium chrysotoxum. The structures of those compounds were elucidated by extensive spectroscopic analysis. Moreover, compounds 1-7 were assessed for inhibitory activity of two enzymes-AChE (acetylcholine esterase) and BChE (butyrylcholine esterase).

• The Korean Journal of Ecology
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• v.24 no.4
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• pp.227-232
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• 2001

The biomass structure for three major components viz., the dominant grass, Chrysopogon zeylanicus Thw., the 'other grasses' and the'remaining species'and dry matter dynamics for total community were studied over a period of one year in an annual fire influenced subtropical humid grassland community in Western Ghats, India. The biomass of aboveground, belowground and litter compartments were high as in other humid grasslands and generally have positive correlation with rainfall, rainy days and relative humidity with the exception of litter parts. The above and belowground net primary productions (4,561 and 722 g/㎡, respectively) were also higher and were comparable with other humid tropical grasslands. The turnover of organic matter was rapid, Of the total input of 14.47 g/㎡ into the system, about 86.3% was allocated to above ground parts and 13.7% to below ground parts. The total disappearance was 2.56 g/㎡ and it was accounted to be 17.68% of the total output. The net surplus of dry matter (82.32%) in the post fire community indicates that the grassland was maintained in a seral stage. Hence it is suggested that prescribed burning may keep this ecosystem in a highly productive and seral stage.

• Molecules and Cells
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• v.27 no.4
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• pp.443-447
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• 2009

This paper reports on the structural rearrangement of satellite DNA type I repeats and heterochromatin during the dedifferentiation and cell cycling of mesophyll protoplasts of cucumber (Cucumis sativus). These repeats were localized in the telomeric heterochromatin of cucumber chromosomes and in the chromocenters of interphase nuclei. The dramatic reduction of heterochromatin involves decondensation of subtelomeric repeats in freshly isolated protoplasts; however, there are not a great many remarkable changes in the expression profile. In spite of that, reformation of the chromocenters, occurring 48 h after protoplast isolation, is accompanied by recondensation of satellite DNA type I; however, only partial reassembly of these repeats was revealed. In this study, FISH and a flow cytometry assay show a correlation between the partial chromocenter and the repeats reassembly, and with the reentry of cultivated protoplasts into the cell cycle and first cell division. After that, divided cells displayed a higher variability in the expression profile than did leaves' mesophyll cells and protoplasts.

• Natural Product Sciences
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• v.4 no.1
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• pp.38-41
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• 1998

From the dried leaves of Isodon eriocalyx (Labiatae) six flavonoids were isolated and two of them were elucidated to be novel ones named 5,7,8,4'-tetrahydroxy-6-methoxyflavone (1), and $isothymusin-8-O-{\beta}-D-glucoside$ (2).