• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.201-207
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• 2016

This study was conducted to produce oligosaccharides from buckwheat hull by using commercial enzymes. Yields of oligosaccharides obtained by enzymatic hydrolysis of the cellulose and hemicellulose fractions were 132.37 and 393.04 g/kg, respectively. Xylose, glucose, fructose, xylobiose, xylotriose, cellobiose, and cellotriose were detected in the hydrolysate produced from buckwheat hull. Antioxidant activity of oligosaccharide from cellulose fraction (OSC) reduced with increasing hydrolysis time; however, the antioxidant activity of oligosaccharide from hemicellulose fraction (OSF) increased as the hydrolysis time was prolonged. OSF and OSC showed higher increase in viable counts compared to the control. As a result, oligosaccharides produced from buckwheat hull by enzymatic hydrolysis showed antioxidant activity and prebiotic effects. It is suggested that utilization of oligosaccharides produced from buckwheat hull as functional food materials may be improved when hydrolysis time and conditions are controlled for this purpose.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.145-149
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• 1997

Lipoxygenase activity from brown rice varieties (Tongjinbyeo, Kumohbyeo and Kanchukbyeo) was investigated using spectrophotometric method. In all three varieties, there was an increase in the enzyme activity with the reaction time. Enzyme activity was tested at different concentration of the substrate. The $V_{max}\;and\;K_m$ values of Tongjin, Kumoh and Kanchukbyeo were 57.89, 19.85 and 31.38 units/mg protein and 0.054, 0.045 and 0.035 mM. The study of lipoxygenase activity at different pH levels showed that all the varieties had maximal activities around $pH\;7.0{\sim}7.6$. The enzyme activity and specific activity on milled fractions of different brown rice varieties, fraction II was superior to the other fractions and fraction IV was inferior to the other fractions. As the result of microwave heating for 0, 30, 60 and 90 sec, the enzyme activity and specific activity of all the varieties were decreased by the elapse of heating time.

• Journal of Educational Research in Mathematics
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• v.14 no.2
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• pp.207-219
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• 2004

There have been studies reporting the increase in student confidence in mathematics when using technology. However, past studies indicating a positive correlation between technology and confidence in mathematics do not explain why they see this positive outcome. With increased availability and easy access to the Internet in schools and the development of free online virtual manipulatives, this research was interested in how the use of virtual manipulatives in mathematics can affect students confidence in their mathematical abilities. Our hypothesis was that the classes using virtual manipulatives which allows students to connecting dynamic visual image with abstract symbols will help students gain a deeper conceptual understanding of math concept thus increasing their confidence and ability in mathematics. The participants in this study were 46 fifth-grade students in three ability groups: one high, one middle and one low. During a two-week unit on fractions, students in three groups interacted with several virtual manipulative applets in a computer lab. Data sources in the project included a pre and posttest of students mathematics content knowledge, Confidence in Learning Mathematics Scale, field notes and student interviews, and classroom videotapes. Our aim was to find evidence for increased level of confidence in mathematics as students strengthened their understanding of fraction concepts. Results from the achievement score indicated an overall main effect showing significant improvement for all ability groups following the treatment and an increase in the confidence level from the preassessment of the Confidence in Learning Mathematics Scale in the middle and high ability groups. An interesting finding was that the confidence level for the low ability group students who had the highest confidence level in the beginning did not change much in the final confidence scale assessment. In the middle and high ability groups, the confidence level did increase according to the improvement of the contest posttest. Through interviews, students expressed how the virtual manipulatives assisted their understanding by verifying their answers as they worked and facilitated their ability to figure out math concept in their mind and visually.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.449-456
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• 1992

Expermient were conducted to determine the effect of phosphorus stress on bacteroid content and energy status of soybean (Glycine max [L.] Merr.) nodules. Plants inoculated with Bradyrhizobium japonicum MN 110 were grown with P-stressed (0.05 mM-P) and control (1 mM-P) treatment in the greenhouse. Phosphorus stress decreased nodule mass per plant and nodule mass to whole plant mass ratio. Phosphorus concentration in leaf, stem and root tissues were reduced by 75% but in nodule tissue was reduced only by 40% under phosphorus stress during 3 week experimental period. The bacteroid content per unit nodule mass and the distribution of total nitrogen and total phosphorus among the bacteroid and plant cell fractions of nodule were not affected significantly by phosphorus stress. Regardless of phosphorus treatment, 22% of the nitrogen and 27% of the phosphorus in whole nodules were associated with the bacteroid fraction. The ATP and total adenylate concentrations in and energy charge of whole nodule were decreased 77%, 46% and 37%, respectively, by phosphorus stress. The ATP concentration in and energy charge of the host plant cell fraction of nodules were decreased 86% and 59%, respectively, but these parametres in bacteroid in nodules were not affected by phosphorus stress. These results indicated that nodule is a strong phosphorus sink and that nodule growth and development are regulated to maintain a high phosphorus and energy content in bacteroid even when the host plant is subjected to phosphorus deficiency.

• Biomedical Science Letters
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• v.12 no.3
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• pp.289-301
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• 2006

Cardiopulmonary bypass (CPB) for cardiac surgery triggers the production and release of numerous chemotactic substances and cytokines, ensuing systemic inflammatory response that leads to postoperative major organ dysfunction. Traditionally, corticosteroids (steroid) have been administered to patients undergoing cardiac surgery to ward off these detrimental physiologic alterations. However, the majority of the studies have been performed on adult patients with high-dose steroid. We carried out a randomized, prospective, double-blind study to compare the efficacy of low-dose steroid with that of high-dose steroid and to determine the adequate dose of pretreated-steroid for prophylactic effects in pediatric cardiac surgery. Thirty pediatric patients scheduled for elective cardiac surgery were randomly assigned to two groups; fifteen patients received low-dose methylprednisolone (10mg/kg intravenously, n=15, low-dose group) and the others received high-dose methylprednisolone (30mg/kg intravenously, n=15, high-dose group) 1 hour prior to CPB. Arterial blood samples were taken before CPB (Pre-CPB), 10 minutes after start of CPB (CPB-10), and immediately after CPB-end (CPB-OFF) for measuring total leukocyte counts (T-WBC) and diff-counts, platelet counts, interleukin-6 (IL-6), myeloperoxidase (MPO), total antioxidant (TAO), neuron-specific enolase (NSE), troponin I (TNI), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and blood urea nitrogen (BUN) levels. Other parameters such as volumes of urine output, pulmonary index $(PI,\;PaO_2/FiO_2)$, mechanical ventilating period, intensive care unit (ICU)-staying period, postoperative complications (fever, wound problem), postoperative 24 hrs and total volumes in blood loss, and hospitalized days were also assessed. All parameters were compared between two groups. There were no significant differences in T-WBC counts, monocyte fraction, platelet counts, TA levels, NSE levels, creatinine levels, BUN levels, the volumes of total urine output, PI, the incidences of fever and wound problem, postoperative 24hrs- and total-blood loss volumes and ICU-staying period between two groups (P>0.05). At CPB-OFF, neutrophil fraction, MPO level, TNI level, and AST level were higher in the high-dose group than in the low-dose group (P<0.05). IL-6 level at CPB-10 was higher in the high dose-group than in the low-dose group (P<0.05). Furthermore, mechanical ventilating periods and hospitalized days of the high-dose group were significantly longer than those of low-dose group (P<0.05). The high-dose group had significantly low lymphocyte fi-action at CPB-OFF compared with the low-dose group (P<0.001). These findings suggest that pretreatment of high-dose steroid is not superior to that of low-dose steroid regrading its potential benefits in pediatric cardiac surgery. Therefore, the conventional strategy of steroid treatment, high-dose pretreatment, should be modified in the cardiac surgery with CPB. However, further studies must be performed on the larger number of patients in as much as small number of patients in this study.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.69-69
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• 2017

Due to the lack in storage facility, considerable amount of rice is stocked in the open air, which causes increased stale flavor and deteriorates palatability and merchantable quality. Lipoxygenase-3(LOX-3) is involved in the production of volatile constituents in stored rice, and the development of stale flavor is delayed in LOX-3 null rice. LOX activity in the rice grain is localized in bran fraction and the tropical Japonica cultivar 'Dawdam' was reported that the absence of LOX-3 is inherited as a simple recessive trait. Also, it was reported that the peroxidation of unsaturated fatty acids occurs at lower levels in the 'Dawdam' bran fraction during storage than in rice varieties with LOX-3. This study was conducted to develop LOX-3 null rice lines using 'Dawdam' and investigate changes of physicochemical properties of the lines stored at different storage temperatures and periods. So we analyzed texture, toyo glossiness value, germination rate and lipoxygenase activity of 15 LOX-3 null rice lines on the condition of which rough rice had been stored at different temperatures (high temperature condition at $35^{\circ}C$ and low temperature condition at $15^{\circ}C$ for 4months. Hardness and stickiness of the lines tendered to be increased when it was stored at high temperature and adhesiveness, springiness, cohesiveness and chewiness was not considerably different according to storage temperatures and periods. The germination rate of HR29062-B-98-2-1-B among LOX-3 null rice lines was higher than another lines, 99.3, 94.0% after 4months stored at low temperature and high temperature, respectively. The lipoxygenase activity was 3,304, 1,601unit/mg protein after 4months stored at low temperature and high temperatures, respectively. So, it is thought that this line will be useful to breed rice varieties with high storability after tested on agricultural traits.

• Journal of Korea Foundry Society
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• v.11 no.6
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• pp.475-481
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• 1991

In this study the fabrication technology and mechanical properties of AC8A/$Al_2O_3$ Composites by squeeze casting process were investigated to develope for application as the piston materials that require good friction, wear resistance, and thermal stability. AC8A/$Al_2O_3$ composistes without a porosity and the break of preform were fabricated at the melt temperature of $740^{\circ}C$, the preform temperature of $500^{\circ}C$, and mold temperature of $400^{\circ}C$ under the applied pressure of $1200kg/cm^2$ as the results of the observation of microstructures. As the results of this study, the tensile strength of AC8A/$Al_2O_3$ composites was not increased linearly with $Al_2O_3$ volume fraction and so it seemed not to agree with the rule of mixture, which had been used often in metal matrix composite. Also the tensile strength after thermal fatigue test was little different from that before the test. Consequently it was thought that AC8A/$Al_2O_3$ composites fabricated under our experimental conditions had a good thermal stability and subsequently a good interface bonding. Wear rate(i.e., volume loss per unit sliding distance) of AC8A/$Al_2O_3$ composites was decreased with $Al_2O_3$ volume fraction and the sliding speed at both room temperature and $250^{\circ}C$ and so there was a good correlation between wear rate and hardness. Also the wear rate of AC/8A20% $Al_2O_3$ composities was obtained the value of $1.65cm^3/cm$ at sliding speed of 1.14m/sec as compared with about $3.0\;{\times}10^{-8}cm^3/cm$ hyereutectie Al-Si alloy(Al-16%Si-2%Cu-1%Fe-1%Ni), which applied presently for piston materials. The wear behavior of $Al_2O_3$ composites was observed to a type of abrasive wear by the SEM view of wear surface.

• Animal Bioscience
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• v.34 no.6
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• pp.1029-1037
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• 2021

Objective: This study was conducted to investigate effects of antifungal substance and carboxylesterase-producing inoculant on fermentation indices and rumen degradation kinetics of whole crop rice (WCR) silage ensiled at different dry matter (DM) contents. Methods: Dual-purpose inoculants, Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1, confirmed both activities of antifungal and carboxylesterase in the previous study. The WCR at mature stage was chopped, and then wilted to obtain three different DM contents consisting of 35.4%, 43.6%, and 51.5%. All WCR forages were applied distilled water (CON) or mixed inoculants with 1:1 ratio at 1×105 colony forming unit/g (INO), and ensiled into 20 L mini silo (5 kg) in quadruplicates for 108 d. Results: The INO silages had lower lactate (p<0.001) and butyrate (p = 0.022) with higher acetate (p<0.001) and propionate (p<0.001) than those of CON silages. Ammonia-N (p<0.001), lactate (tendency; p = 0.068), acetate (p = 0.030), and butyrate (p<0.001) concentrations of INO silages decreased linearly with increasing DM content of WCR forage. The INO silages presented higher lactic acid bacteria (p<0.001) with lower molds (p<0.001) than those of CON silages. Yeasts (p = 0.042) and molds (p = 0.046) of WCR silages decreased linearly with increasing DM content of WCR forage. In the rumen, INO silages had higher the total degradable fraction (p<0.001), total volatile fatty acid (tendency; p = 0.097), and acetate (p = 0.007), but lower the fractional degradation rate (p = 0.011) and propionate (p<0.001) than those of CON silage. The total degradable fraction (p<0.001), total volatile fatty acid (p = 0.001), iso-butyrate (p = 0.036), and valerate (p = 0.008) decreased linearly with increasing DM content of WCR forage, while the lag phase (p<0.001) was increased linearly. Conclusion: This study concluded that application of dual-purpose inoculants on WCR silage confirmed antifungal and carboxylesterase activities by inhibiting mold and improving rumen digestibility, while increase of wilting times decreased organic acids production and rumen digestibility.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.190-196
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• 1994

Alkali soluble(AS) fraction, revealed the highest antitumor activity of the alkali extracted fractions of G. lucidum IY 009, was loaded on DEAE cellulose(OH$^{-}$ form) column. AS-1, AS-2, AS-3, AS-4 and AS-5 were obtained by stepwise elution with H$_{2}$O, 0.1 M NaHCO$_{3}$, 0.3 M NaHCO$_{3}$, 0.5 M NaHCO$_{3}$ and 0.5 N NaOH respectively, and their antitumor activities(I.R. %) against the sarcoma 180 were 97.5%, 68.0%, 73.0%, 81.0% and 66.0% respectively. AS-1 observed highest antitumor activity was appeared as single peak on the Sepharose CL-4B column chromatography, and their molecular weight was about 580,000 dalton. The carbohydrate content of AS-1 was 98.9%, their monosaccharide consisted of 67.5% of mannose, 22.5% of xylose, 5.8% of glucose, 1.8% of galactose and 2.0% of ribose. AS-1 was assumed $\alpha $linkaged xylomannan having infrared absorption at 864.3 cm$^{-1}$. The main alditol acetates of AS-1 were identified as 1,5-Di-O-acetyl1-2,3,4-Tri-O-methylxylitol, 1,4,5-Tro-O-acety1-2,3,6-Tri-O-methylmannitol and 1,3,4,5-Tetra-O-acety1-2,6-Di-O-methylmannitol by methylation analysis, and their molar ratio was 1 : 2 : 1. The core portion of AS-1 might be $\alpha $-(1$\longrightarrow $ 4)mannopyranosyl unit branched with side chain, C1 of xylopyranosyl residue linked to C3 of every 3 mannopyranosyl units, and the degree of polymerization of structural unit in AS-1 was about 835.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.259-273
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• 1998

The hydroacoustic surveys to provide the essential information for the assessment, management and utilization of fishery resources in the southern waters of Korea were carried out during five research cruises between October 1996 and October 1997 by the training ship KAYA of Pukyong National University. These hydroacoustic investigations were designed to obtain more precise estimates of the geographic distribution, absolute abundance and biological characteristics of the fishery resources, and the vertically integrated densities of fish in terms of volume backscattering strength(SV) by survey region and depth bins, such as the entire water column and the 0~ 10 m from bottom fraction, were measured separately. Hydroacoustic data were collected by using a Simrad EK 500 Scientific echo sounder operating at two frequencies of 38kHz and 120kHz and the data stored in field were later processed on a HP PC using a Simrad EP 500 echo integration and target strength analysis system. The biological compositions of echo signal were identified and sampled using a demersal trawl during daylight hours. The mean target strength to scale the echo integration data for hydroacoustic surveys was derived from the relationship between the SV and the weight of trawl catch per unit volume of the water column sampled by demersal trawls. The results obtained can be summarized as follow : 1. The mean volume backscattering strength for the entire water column in the southern waters of Korea between 1996 and 1997 were -67.2 dB and -70.9 dB at two frequencies of 38 kHz and 120 kHz , respectively, and for the bottom layer of the 0-10 m from bottom friction were -68.8 dB, -70.2 dB, respectively. That is, the volume backscattering strength for the entire water column at low frequency was higher than that at high frequency. 2. The relationship between the mean backscattering strength (〈SV〉, dB) for the depth strata of trawl hauls and the weight (C, kg/m3) per cubic meter of the catch sampled by bottom trawling in the southern waters of Korea in January and July 1997 were expressed by the following equations: 38 kHz : 〈SV〉= -28.2 + 10 log(C), 120 kHz : 〈SV〉= -32.4 + 10 log(C). The mean weight -normalized target strengths derived from these equitions were -28.2 dB/ kg, -32.4 dB/ kg at 38 kHz and 120 kHz , respectively. That is, the mean weight -normalized target strength at 38 kHz was 4.2 dB higher than that at 120 kHz. 3. The distribution density of fish in terms of biomass per unit volume in the southern waters of Korea were estimated to be 125.9 $\times$ 10-6 kg/m3 and 141.3 $\times$ 10-6 kg/m3 at 38 kHz and 120 kHz , respectively.