• YAKHAK HOEJI
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• v.27 no.3
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• pp.215-220
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• 1983

To elucidate the effect of ginseng butanol fraction on streptozotocin-induced hyperglycemia, ginseng butanol fraction was administered before and after injection of streptozotocin(50mg/kg, i.v.), and glucose, insulin, and cholesterol levels in serum were determined at 96 hours after streptozotocin injection. Serum glucose, insulin levels were significantly decreased by administration of ginseng butanol fraction (100mg/kg, p.o.) at 7 hour and 7, 4, 1, hour(three times) before streptozotocin injection. The glucose levels were significantly decresed by administration of ginseng butanol fraction at 1 hour (100mg/kg) after strcptozotocin injection, and also serum glucose levels in groups of continuous administration of ginseng butanal fraction(100mg/kg) for 3 days after streptozotocin injection were markedly decreased than in group of single dose of ginseng butanol fraction. Ginseng butanol fraction has the protective and relieving action against streptozotocin-induced hyperglycemia.

• YAKHAK HOEJI
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• v.25 no.4
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• pp.199-204
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• 1981

The methanol extract of Thalictrum uchiyamai Nakai was fractionatedi nto four parts; (1) ether soluble nonphenolic fraction (2) phenolic tertiary bases fraction, (3) chloroform soluble tertiary bases fraction and (4) aqueous quaternary bases fraction. The fractions of this plant showed a total of twenty-four spots on the silica gel TLC. Ether soluble nonphenolic fraction and ether soluble phenolic fraction showed nine alkaloid spots respectively, chloroform soluble fraction showed three alkaloid spots and quaternary bases fraction showed three alkaloid spots. The antimicrobial activity of the four extracts was shown as follows; nonphenolic tertiary bases inhibited the growth of Micrococcus dutica at the concentration of $50\mu$g/ml, in phenolic tertiary bases $500\mu$g/ml concentration was inhibitory to Micrococcus dutica and to Staphyloccus aureus. In aqueous quaternary bases, $500\mu$g/ml concentration was inhibitory to Klebsiella pneumonae. Chloroform soluble tertiary fraction showed slight activity. All of bases showed reproducible activity against tested microorganisms.

• East Asian mathematical journal
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• v.38 no.4
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• pp.379-396
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• 2022

In this paper, we investigate distribution strategies in the Egyptian fraction, and through this, we examine the distribution strategies of (fraction)÷(fraction) and then provide some educational implications. The (natural number)÷(natural number) of the sharing situation has the meaning of 'share' per unit, which can be seen as a situation where the unit ratio is determined. These concepts can also naturally be extended to the case of (fraction)÷(fraction) by some problem posing situations. That is to say, the case of (fraction)÷(fraction) can be deduced the case (natural number)÷(natural number) by the re-statement of the problem.

• Biomolecules & Therapeutics
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• v.5 no.4
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• pp.331-335
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• 1997

In a preliminary screening of plant extracts for the antigastritic and antiulcer actions in rats, the methanol extracts of Taheebo showed positive activity in HCI . ethanol-induced gastric lesion. Among the systematic fractions of hexane, chloroform, butanol and water, the most potent $H_2O$ fraction reduced significantly HCI . ethanol-induced gastric lesion at the oral dose of 300 mg/kg. In pylorus ligated rats chloroform and butanol fraction showed decreases in the volume of gastric secretion and acid output of which effects were stronger in chloroform fraction. Further assays with hexane butanol and $H_2O$ fraction disclosed that it significantly suppressed the aspirin-induced ulcer. The butanol fraction reduced significantly acetic acid induced ulcer at the dose of 400 mg/kg. The butanol and $H_2O$ fraction reduced the malondialdehyde level in HCI . ethanol-induced gastric lesion. In pylorus ligated rats, chloroform and butanol fraction reduced the malondialdehyde level and in aspirin-induced ulcer, chloroform fraction reduced that levle. These results might suggest that the butanol and $H_2O$ fraction of Taheebo had inhibitory action in gastric lesion and ulceration through inhibition of gastric acid secretion and the decrease malondialdehyde level.

• Journal of the Korean School Mathematics Society
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• v.12 no.2
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• pp.151-170
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• 2009

The purpose of the study is to analyze the sixth graders' understanding of concepts and operation about fraction. The test was administered and analyzed to 707 sixth graders' performance on fractions after the fraction instructions in elementary schools in Seoul, Korea. The participants are asked to answer two sets of questions for 40 minutes. First, they are asked to answer to 16 problems about the concepts of fraction with respect to part-whole, ratio, operator, measure, quotient, equivalent, and operations. Second, specially, to investigate sixth graders' ability of drawing and describing the situation of division including fraction, the descriptive problem asked students (1) to describe $3\;{\div}\;\frac{1}{2}$ into pictorial representation and (2) to write the solving process. The participants of this study didn't show deep understandings about the concepts and operation of fraction. The degree of understanding of subconstructs of fraction shows that their knowledge of ratio concept with respect to fraction was highest while their understanding of measure with respect to fraction was lowest. Considering their wrong answers, about 59% of participants showed misconception to the question of naming one fraction that appears between $\frac{1}{5}$ and $\frac{1}{6}$. Further, they didn't explain their understanding with drawing about the division of fraction ($3\;{\div}\;\frac{1}{2}$).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.498-503
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• 2015

This study was conducted to evaluate the cytotoxicity and ${\alpha}-Amylase$, ${\alpha}-Glucosidase$, pancreatic lipase inhibition in vitro by different solvent fractions from the roots of Codonopsis lanceolata. The values of $IC_{50}$ against Calu-6 cell showed a high effect in n-hexane fraction ($10.13{\mu}g/mL$) whereas DW fraction exhibited the weakest inhibition on cell viability, having an $IC_{50}$ value of over $1,000{\mu}g/mL$. The values of $IC_{50}$ against HCT-116 cell showed the highest activity in n-BuOH fraction ($102.01{\mu}g/mL$), followed by n-hexane fraction ($145.85{\mu}g/mL$), methylene chloride fraction ($332.02{\mu}g/mL$), ethyl acetate fraction ($462.93{\mu}g/mL$) and DW fracion ($>1,000{\mu}g/mL$). ${\alpha}-Amylase$ inhibitory activity in methylene chloride fraction and ethyl acetate fraction was found to have a higher inhibitory effect with 24.5% and 25.6% than the other fractions. The highest ${\alpha}-Glucosidase$ inhibitory activity was observed from the ethyl acetate fraction extract, while the extract of DW fraction showed the lowest level of inhibitory activity at given experiment concentration. The pancreatic lipase inhibitory activity of C. lanceolata was found to have a higher the effect in ethyl acetate fraction. Inhibition of lipase activity of the ethyl acetate fraction and n-hexane fraction showed a relatively high, while the extract of DW fraction showed the lowest level at given experiment concentration. These results suggested that the roots of C. lanceolata may assist in the potential biological activity on carbohydrate, lipid Inhibitory activity and anticancer activity.

• Journal of Pharmaceutical Investigation
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• v.8 no.1
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• pp.6-16
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• 1978

We obtained 4 kinds of extract fraction from Acanthopanacis Radicis Cortex and studied on the influence to the blood pressure of rabbit. These 4 fractions were obtained as follows; Fraction I was insoluble fraction by 99% ethanol from 80% methanol extract of Acanthopanacis Radicis Cortex, fraction II, precipitated fraction by ether from 99% ethanol soluble fraction of 80% methanol extract of Acanthopanaacis Radicis Cortex, fraction III, no precipitated fraction by ether from 99% ethanol soluble fraction of above 80% methanol extract and fraction IV, water extract of Acanthopanacis Radicis Cortex. All of fractions, when administered into ear-vein of rabbit, produced fall of blood pressure. Among these 4 fractions, although fraction III was not only the most potent but had the greatest efficacy, we observed the mechanism of hypotensive action of Acanthopanacis Radicis Cortex, making use of fraction II which was thought as a comparatively pure fraction. Hypotensive action of fraction II (APF II) was not affected by vagotominization but markedly inhibited by atropine. Pretreatment of bethanidine showed a tendency to weaken the depressor action of APF II, although it was not a significant result, but diphenhydramine did not influence APF II action. Phentolamine, guanethidine and chlorisondamine inhibited significantly the hypotensive action of APF II. APF II elicited the potentiation of norepinphrine pressor action dependent on the time-factor whereas it did not influence angiotesin pressor action. It is seemed that APF II exhibited hypotensive action, causing peripheral muscarinic-effect and centrally induced sympatholytic action.

• Journal of Educational Research in Mathematics
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• v.15 no.3
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• pp.287-313
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• 2005

The decimal fraction concept plays an important role in understanding the real number which is one of the major concepts in school mathematics. In the school mathematics of Korea, the decimal fraction is treated merely as a sort of name of the common fraction, while many other important aspects of the decimal fraction concept are ignored. In consequence students fail to understand the decimal fraction concept properly, and merely consider it as a kind of number for formal computation. Preceding studies also identified students' narrow understanding of the decimal fraction concept. But none of them succeeded in clarifying the essences of the decimal fraction concept, which are crucial for discussing the didactical problems of it. In this study we attempted a didactical analysis of the decimal fraction concept and disclosed the roots of didactical problems and presented measures for its improvement. First, we attempted a phenomenological analysis of the decimal fraction concept and extracted 9 elements of the decimal fraction concept. Second, we has analyzed of the essence of the decimal fraction concept more clearly by relating it to the situations where it functions and its representations. For this we tried to construct the conceptual field of the decimal fraction. Third, we categorized he developmental levels of the decimal fraction concept from the aspect of external manifestation of the internal order. On the basis of these results, we attempted hierarchical structuring of the elements of the decimal fraction concept. And using the results of such a didactical analysis on the decimal number concept we analyzed the mathematics curriculum and textbooks of our country, investigated levels of students' understanding of the decimal fraction concept, and disclosed related problems. Finally we suggested directions and measures for the improvement of teaching decimal fraction concept.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.14-14
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• 2018

This Camptotheca acuminata Decne. (CA), belonging to Nyssaceae, is a deciduous tree. and has been used as Traditional Chinese medicine since ancient times. The CA produces camptothecin a natural indole alkaloid, and reported to have anti-cancer effects. But the studies on biological activities of CA leaves are insufficient. Therefore, this study confirmed various biological activities such as antioxidant, antidiabetic, anticancer, antiinflammatory and metabolism analysis by HPLC-MS/MS of CA leaves. The $RC_{50}$ values of DPPH radical scavenging activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, water fraction and n-Hexane fraction were $12.23{\pm}0.01$, $15.93{\pm}0.42$, $55.12{\pm}0.45$, $56.29{\pm}4.15$ and $427.29{\pm}6.13ug/mL$, respectively. The $IC_{50}$ values of ${\alpha}$-glucosidase inhibitory activity of ethyl acetate fraction, n-Butanol fraction, methanol extraction, n-Hexane fraction and water fraction were $24.29{\pm}0.14$, $47.86{\pm}0.45$, $54.23{\pm}1.21$ $466.76{\pm}2.21$ and $623.91{\pm}9.67ug/mL$, respectively. The nitric oxide release activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The anti-cancer activity of n-Hexane fraction, methanol extraction, ethyl acetate fraction, water fraction and n-Butanol fraction were $31.49{\pm}5.74$, $29.79{\pm}0.71$, $26.89{\pm}0.71$, $8.24{\pm}5.83$ and $7.75{\pm}4.08%$ at 25 ug/mL, respectively. The ethyl acetate fraction activities showed higher biological activities than other fractions. Thus, Additional studies were conducted using ethyl acetate fraction. Metabolite analysis was performed using a LCMS-8040 triple quadrupole mass spectrometer. As a result, Five compounds (1-5) were identified in the ethyl acetate fraction of the CA leave. The identification of these compounds was generated by the analysis of fragmentation methods of the negative and positive ion modes. Five compounds were identified as gallic acid (1), chlorogenic acid (2), isoquercetin (3), astragalin (4) and camptothecin (5). These results suggest that the CA leave can be used for functional materials.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.400-406
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• 1997

Chemical composition and antimicrobial activity of Houttuynia cordata Thunb. were investigated to develop a natural food preservative from it. Aspartic acid, glutamic acid, glycine and arginine were major amino acids of Houttuynia cordata Thunb., but were present in a trace amount. Free sugars were composed of glucose, fructose, sucrose and maltose and major fatty acids were linolenic acid, linoleic acid, oleic acid, and palmitic acid. Mineral elements were potassium, calcium, magnesium, iron, zinc, and copper. Antimicrobial activities were shown in acidic, neutral and phenolic fraction of Houttuynia cordata Thunb., but not in basic fraction. Among the four fractions, neutral fraction showed the strongest antimicrobial activities against microorganisms tested, such as Pseudomnas aeruginosa, Micrococcus luteus, Bacillus subtilis, Aspergillus parasiticus and Aspergillus flavus. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the neutral fraction varied according to microoganisms tested. The lowest values of MIC (0.0075 g eq./mL) and MLC (0.10 g eq./mL) were obtained from Pseudomonas aeruginosa.