• The Mathematical Education
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• v.51 no.1
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• pp.21-45
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• 2012

The purpose of the study was to investigate how students understand each operations with whole numbers and fractions, and the relationship between their knowledge of operations with whole numbers and conceptual understanding of operations on fractions. Researchers categorized students' understanding of operations with whole numbers and fractions based on their semantic structure of these operations, and analyzed the relationship between students' understanding of operations with whole numbers and fractions. As the results, some students who understood multiplications with whole numbers as only situations of "equal groups" did not properly conceptualize multiplications of fractions as they interpreted wrongly multiplying two fractions as adding two fractions. On the other hand, some students who understood multiplications with whole numbers as situations of "multiplicative comparison" appropriately conceptualize multiplications of fractions. They naturally constructed knowledge of fractions as they build on their prior knowledge of whole numbers compared to other students. In the case of division, we found that some students who understood divisions with whole numbers as only situations of "sharing" had difficulty in constructing division knowledge of fractions from previous division knowledge of whole numbers.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.202-206
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• 1997

To develop mil fat fractions with desirable physico-chemical properties, anhydrous milk fat (AMF) was fractionated by one- and two-stage extractions using supercritical $CO_2$(SC-$CO_2$). Tow-stage extraction of AMF was performed by first producing tow fractions, an extract and a residue at 4$0^{\circ}C$/241bar, which were subsequently used as the feed for an extraction at 6$0^{\circ}C$/241bar and 4$0^{\circ}C$/345bar, and separated into five and four fractions, respectively, based one extraction time. These fractions were quantified and analyzed for fatty acids and physico-chemical properties. SHort-chain (C4~C8) fatty acids in extract fractions from an extract were 200~150% compared with those of the original AF. Long-chain (C14~C18) fatty acids in extract fractions from a residue were 118~141%. The ratio of unsaturated fatty acids in the residue fraction was 131%. Melting point ranged from 22 to 43$^{\circ}C$, iodine value 21.8 to 36.9, and saponification value 255 to 221 in the extract and residue fractions. SC-$CO_2$ fractionation of AMF by two-stage extraction offers the possibility of developing ractions with discrete fatty acid compositions and physico-chemical properties such as melting point, iodine value and saponification value.

• YAKHAK HOEJI
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• v.52 no.2
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• pp.117-124
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• 2008

The leaves of Perilla frutescens Britt. var. japonica Hara (Labiatae) are often used in gourmet food in several Asian countries. Two kinds of perilla cultivars, Namcheon (NC) and Bora (BR), have been respectively developed in Korea by the pure line of 'deulkkae' from the local variety and by the cross of 'deulkkae' and 'chajogi'. The present study evaluated and compared antioxidant and neuroprotective effects of the fractions prepared from the leaves of the two cultivars using cell-free bioassay systems and primary cultured rat cortical cells. We found that the spirit, chloroform, hexane and butanol fractions from NC and BR leaves inhibited lipid peroxidation initiated in rat brain homogenates by $Fe^{2+}$ and L-ascorbic acid. In contrast, only the spirit and butanol fractions from both cultivars exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Among the fractions tested, the butanol fractions from NC and BR leaves exhibited the most potent antioxidant properties, and the butanol fraction from BR was more potent than the NC fraction. In consistence with these findings, the butanol fractions from both cultivars protected primary cultured cortical cells from the oxidative damage induced by $H_2O_2$ or xanthine and xanthine oxidase, with the BR butanol fraction being more active. The butanol fractions from NC and BR did not produce cytotoxicity in our cultures treated for 24 h at the concentrations of up to $100\;{\mu}g/ml$. Taken together, these results indicate that the leaves of the two cultivars of Perilla frutescens exert antioxidant and neuroprotective effects, and that the butanol fraction from BR leaves exhibits the most potent antioxidative neuroprotection among the fractions tested in this study.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7167-7170
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• 2015

Background: Although 3D image based brachytherapy is currently the standard of treatment in cervical cancer, most of the centres in developing countries still practice orthogonal intracavitary brachytherapy due to financial constraints. The quest for optimum dose and fractionation schedule in high dose rate (HDR) intracavitary brachytherapy (ICBT) is still ongoing. While the American Brachytherapy Society recommends four to eight fractions of each less than 7.5 Gy, there are some studies demonstrating similar efficacy and comparable toxicity with higher doses per fraction. Objective: To assess the treatment efficacy and late complications of HDR ICBT with 9 Gy per fraction in two fractions. Materials and Methods: This is a prospective institutional study in Southern India carried on from $1^{st}$ June 2012 to $31^{st}$ July 2014. In this period, 76 patients of cervical cancer satisfying our inclusion criteria were treated with concurrent chemo-radiation following ICBT with 9 Gy per fraction in two fractions, five to seven days apart. Results: The median follow-up period in the study was 24 months (range 10.6 - 31.2 months). The 2 year actuarial local control rate, disease-free survival and overall survival were 88.1%, 84.2% and 81.8% respectively. Although 38.2% patients suffered from late toxicity, only 3 patients had grade III late toxicity. Conclusions: In our experience, HDR brachytherapy with 9 Gy per fraction in two fractions is an effective dose fractionation for the treatment of cervical cancer with acceptable toxicity.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.10-16
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• 2011

We investigated the antimicrobial activity of ether and ethylacetate fractions from Artemisia capillaris and Artemisia iwayomogi used as Injin. The antimicrobial activity of the ethylacetate fractions from Artemisia capillaris and Artemisia iwayomogi for tested microbes were stronger than those of ether fractions of the two Artemisia plants. The antimicrobial activity of fractions of Artemisia iwayomogi was higher than that of fractions of Artemisia capillaris for the tested microbes. The extracts of young shoots and leaves showed stronger antimicrobial activity than those of young leaves. The range of minimum inhibitory concentrations(MICs) of ethylacetate fractions from the part of Artemisia capillaris and Artemisia iwayomogi were 0.25~2.0 mg/ml. The MICs of ether fractions were showed higher concentration than those of ethylacetate fractions. The fractions of Artemisia iwayomogi showed lower MICs than fractions of Artemisia capillaris. The highest total polyphenol content was found in young shoots and leaves of A. capillaris. The young shoots and leaves of the two kinds of Artemisia plants showed higher content of total polyphenol.

• The Korean Journal of Food And Nutrition
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• v.32 no.5
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• pp.553-559
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• 2019

To investigate the effects of antioxidant activities and hair loss prevention of extracts from Platycodon grandiflorum, we've prepared chloroform (CF) and ethylacetate fractions (EA) extracted from P. grandiflorum. In the results of DPPH radical scavenging assay, the two fractions showed dose-dependent antioxidant activities. Furthermore, in the ABTS assay, the two fractions exhibited the inhibitory effect over 90% at 10, 50, 100, 200 mg/mL. To investigate the inflammation inhibitory effect, we used RAW264.7 cells, these extracts were inhibited inflammatory reaction by suppressing the production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) in dose-dependent manner. In the assay of HaCaT cells' proliferation, the 24 hr treatment of the extracts significantly accelerarted cell proliferation in the range of concentrations used. The two fractions inhibited the proliferation of Malssezia furfur, the bacteria induce the dandruff. Finally, the CF could significantly inhibit the DHT production at 1, 10, 50, $100{\mu}g/mL$, but EA showed the inhibitory effect at the concentration over $50{\mu}g/mL$. The overall results of this study suggest that the chloroform (CF) and ethylacetate fractions (EA) from P. grandiflorum could be a useful raw material for the hair loss prevention products.

• The Mathematical Education
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• v.57 no.4
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• pp.453-475
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• 2018

This study examines how elementary students understand fractions with operations conceptually and how they perform procedures in the division of fractions. We attempted to look into students' understanding about fractions with divisions in regard to mathematical proficiency suggested by National Research Council (2001). Mathematical proficiency is identified as an intertwined and interconnected composition of 5 strands- conceptual understanding, procedural fluency, strategic competence, adaptive reasoning, and productive disposition. We developed an instrument to identify students' understanding of fractions with multiplication and division and conducted the survey in which 149 6th-graders participated. The findings from the data analysis suggested that overall, the 6th-graders seemed not to understand fractions conceptually; in particular, their understanding is limited to a particular model of part-whole fraction. The students showed a tendency to use memorized procedure-invert and multiply in a given problem without connecting the procedure to the concept of the division of fractions. The findings also proposed that on a given problem-solving task that suggested a pathway in order for the students to apply or follow the procedures in a new situation, they performed the computation very fluently when dividing two fractions by multiplying by a reciprocal. In doing so, however, they appeared to unable to connect the procedures with the concepts of fractions with division.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7337-7342
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• 2015

The study aimed to investigate the profile of alkaloids in two ethyl acetate soluble fractions, namely fractions A and B from an ethanolic extract of Ficus septica leaves and cytotoxic effect on T47D breast cancer cells. Preparation of both fractions involved maceration of leaves with 70% (v/v) ethanol, filtration with $Al_2O_3$, precipitation with 0.1 N HCl, Mayer reagent, and 0.1 N NaOH, and also partition with ethyl acetate. Qualitative thin layer chromatography (TLC) was conducted to determine the profile of alkaloids in the two fractions, using alkaloid specific reagents such as Dragendorff, sodium nitrite, and Van Urk-Salkowski. Cytotoxic effects of both fractions on T47D cells were evaluated using MTT assay with a concentration series of 1.56; 3.12; 6.25; 12.5; 25 and $50{\mu}g/mL$. The TLC test showed that fractions A and B contained alkaloids with Rx values of 0.74 and 0.80 for fraction A and 0.74, 0.84, 0.92 for fraction B with regard to yohimbine using the mobile phase of n-buthanol:glacial acetic acid:distilled water (3:1:1 v/v/v). Moreover, an indole alkaloid was detected with Rx values of 0.80 and 0.84, respectively. Fractions A and B exhibited high cytotoxic effects on T47D cells with IC50 values of 2.57 and $2.73{\mu}g/mL$, respectively. In conclusion, overall the results of this study showed that fractions of Ficus septica contain alkaloids including indole alkaloid or its derivatives and possess a cytotoxic effect on T47D cells. This research supports the idea that alkaloids in F. septica have anticancer activity.

• Journal of Life Science
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• v.10 no.6
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• pp.617-620
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• 2000

Methanol extract of Sarcodon aspratus Berk. (S. Ito) was analyzed by thi layer chromatography, gas chromatography and mass spectrophotometer. Nine fractions from primary methanol extract were observed by TLC. Six fractions were observed by the second TLC analysis of the second and the third fractions. 27,28-digydrolanosterol({TEX}$C_{30}H_{52}${/TEX}O), ergost-7-en-3-ol({TEX}$C_{28}H_{48}${/TEX}O) were identified from two fractions of the second TLC analysis by mass spectrophotometer. The molecular weights of 27,28-dihydrolanosterol and ergost-7-en-3-ol were 413 and 400 respectively.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.26-32
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• 1977

The multiple 7S globulins composed of two fractions (A and B) in the electrophoresis with Davis' method were isolated at different stages of the soybean seed development. Electrophoresis of their subunits liberated in PAWU solvent [phenol-acetic acid-water (2 : 1 : 1) solution plus 5M urea] yielded 4 major bands. Observation of both the electrophoretic bands of the multiple 7S fractions(7S-A and 7S-B) and those of their subunits was suggestive of a similarity of the subunit pattern between two 7S fractions. The two fractions in multiple 7S globulins were isolated with DEAE-Sephadex A-50 column$(2.0{\sim}100cm)$ chromatography. They were separated into 2 fractions in a linear gradient concentration of 0.28 to 0.40M NaCl with phosphate buffer (pH 7.8) containing 10mM ${\beta}-mercaptoethanol$(ME). The isolated protein was dissociated into subunits with two different solvent systems; in PAWU solvent and in Tris-HCl buffer(pH 8.0) containing 1% sodium dodecyl sulfate (SDS) and 40mM ME. The dissociated subunits were subjected to electrophoresis in PAWU-treated 7.5% acrylamide gel and in 1% SDS-treated 5.6% acrylamide gel. In PAWU gel electrophoresis, total 7S globulin was separated into 5 major bands, two of which were occupied in common by two 7S fractions(7S-A and 7S-B). In SDS gel electrophoresis, total 7S globulin was separated into 7 major bands, three of which were overlapped with the subunit of the two 7S fractions. The above results alluded us to the presence of a common and/or similar subunit between the multiple 7S globulins.