• Journal of Environmental Science International
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• v.17 no.2
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• pp.211-224
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• 2008

Characteristics of the esterification reaction between free fatty acid in rice bran oil and methanol was investigated in the presence of catalysts, such as PTS(p-toluene sulfonic acid), Amberlyst 15 dry and SCX(silica gel based strong cation exchange resin). While reaction temperature was kept constant at $65^{\circ}C$, initial feed content of free fatty acid was varied from 100% to 1% by addition of pure free fatty acid which was previously made from rice bran oil. Also, the effect of mole ratio of methanol to fatty acid on the final conversion was examined. When esterification of pure free fatty acid was catalyzed by several acids, final conversions were increased in order of Amberlyst 15 dry, SCX and PTS. Using PTS catalyst, initially the reaction proceeded in homogeneous 2nd oder reaction mechanism. However, phase of reaction mixture changed from homogeneous to heterogeneous along the reaction time and then reaction rate was retarded by mass transfer resistance of methanol. Final conversion of free fatty acid in reaction mixture was depended on initial feed content of free fatty acid, and had maximum value at 30% of initial feed free fatty acid content for all kinds of catalysts used. And the final conversion was increased with mole ratio of methanol by the improvement of reaction rate. When initial feed free fatty acid content below 10% and the reaction was catalyzed by PTS, concentration of free fatty acid in reaction mixture was increased in the middle of reaction time by hydrolysis of triglyceride in reaction mixture. Also, if silica gel was added into the reaction mixture which had initial feed free fatty acid content below 50%, final conversion was increased by the adsorption of moisture produced. The SCX catalyst made the esterification reaction of free fatty acid to progress like in case of PTS catalyst. However, when initial feed free fatty acid content below 10%, concentration of free fatty acid in. reaction mixture was decreased monotonically and not increased in the middle of reaction time on the contrary to the case of PTS. Thus, SCX catalyst accomplished more high value of final conversion than PTS catalyst for the initial feed fatty acid content range from 50% to 5% In case of initial feed free fatty acid content of 1% and mole ratio of methanol was 2, concentration of free fatty acid in reaction mixture increased over the initial feed free fatty acid content for all kind of catalysts used. Although SCX catalyst was added into reaction mixture which had 1% of initial feed fatty acid content, final conversion was hardly raised by mole ratio of methanol.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.430-436
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• 2010

The objective of the present studies was to develop and validate a system for isolation, purification and extended culture of pigment-producing cells in alpaca skin (melanocytes) responsible for coat color and to determine the effect of alpha melanocyte stimulating hormone treatment on mRNA expression for the melanocortin 1 receptor, a key gene involved in coat color regulation in other species. Skin punch biopsies were harvested from the dorsal region of 1-3 yr old alpacas and three different enzyme digestion methods were evaluated for effects on yield of viable cells and attachment in vitro. Greatest cell yields and attachment were obtained following dispersion with dispase II relative to trypsin and trypsin-EDTA treatment. Culture of cells in medium supplemented with basic fibroblast growth factor, bovine pituitary extract, hydrocortisone, insulin, 12-O-tetradecanolphorbol-13-acetate and cholera toxin yielded highly pure populations of melanocytes by passage 3 as confirmed by detection of tyrosinase activity and immunocytochemical localization of melanocyte markers including tyrosinase, S-100 and micropthalmia-associated transcription factor. Abundance of mRNA for tyrosinase, a key enzyme in melanocyte pigment production, was maintained through 10 passages showing preservation of melanocyte phenotypic characteristics with extended culture. To determine hormonal responsiveness of cultured melanocytes and investigate regulation of melanocortin 1 receptor expression, cultured melanocytes were treated with increasing concentrations of ${\alpha}$-melanocyte stimulating hormone. Treatment with ${\alpha}$-melanocyte stimulating hormone increased melanocortin receptor 1 mRNA in a dose dependent fashion. The results demonstrated culture of pure populations of alpaca melanocytes to 10 passages and illustrate the potential utility of such cells for studies of intrinsic and extrinsic regulation of genes controlling pigmentation and coat color in fiber-producing species.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.105-109
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• 2011

To determine mixing ratios for mixtures of rapeseed oil and other oils, an electronic nose (E-nose) based on a mass spectrometer system was used. Rapeseed oil was blended with soy bean oil or corn oil at ratios of 100:0, 97:3, 94:6, 91:9, 88:12, 85:15, and 80:20, respectively. The intensities of each fragment from the mixed rapeseed oil by E-nose based on MS were completely different from those of the soy bean oil and corn oil. The obtained data were used for discriminant function analysis (DFA). DFA plots indicated a significant separation of pure rapeseed oil and soy bean oil or corn oil and their mixtures. The added concentration of soy bean oil or corn oil to rapeseed oil was highly correlated to the first discriminant function score (DF1). When soy bean oil was added to rapeseed oil, it was possible to predict the following equation: DF1=-0.170*conc. of soy bean oil+0.431 ($r^2=0.989$). For corn oil the equation was: DF1=-0.1*conc. of corn oil+0.4 ($r^2=0.844$). The use of an E-nose based on a MS system is as an efficient method for the authentication of pure rapeseed oil.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.609-614
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• 2009

Sesame oil was sometimes replaced by mixed oil due to high price in Korean market. To find out authentic sesame oil, electronic nose (E-nose) based on mass spectrometer system was used. Sesame oil was blended with perilla oil at the ratio of 97:3, 94:6, 91:9, 88:12 and 85:15, respectively. Intensities of each fragment from sesame oil by E-nose based on MS were completely different from those of perilla oil. The obtained data was used for discriminant function analysis. For quantitative analysis, the partial least square algorithm was used. The added concentration of perilla oil to sesame oil was correlated with discriminant function first score (DF1) and second score (DF2). From this relationship it could be found out how much perilla oil added. DFA plot indicated a significant separation of pure sesame oil and pure perilla oil. The different geographical origin of sesame oil was used for blending with perilla oil were closed to that of sesame oil. Korean sesame oil mixture and Indian sesame oil one were well separated. And the correlation between mixing ratios and DF1 values was found at the ratio of 97:3, 91:9, and 85:15 (SE vs PE oil), respectively. But the added concentration of perilla oil to sesame oil was correlated with discriminant function first score (DF1). E-nose based on MS system could be used as an efficient method for purity of oil quality.

• Journal of Animal Science and Technology
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• v.59 no.11
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• pp.27.1-27.7
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• 2017

Background: Cashew nut shell liquid (CNSL) is an agricultural byproduct containing alkylphenols that has been shown to favorably change the rumen fermentation pattern only under experimentally fixed feeding conditions. Investigation of CNSL potency in rumen modulation under a variety of feeding regimens, and evidence leading to the understanding of CNSL action are obviously necessary for further CNSL applications. The objective of this study was to evaluate the potency of CNSL for rumen modulation under different dietary conditions, and to visually demonstrate its surfactant action against selected rumen bacteria. Methods: Batch culture studies were carried out using various diets with 5 different forage to concentrate (F:C) ratios (9:1, 7:3, 5:5. 3:7 and 1:9). Strained rumen fluid was diluted with a buffer and incubated with each diet. Gas and short chain fatty acid (SCFA) profiles were characterized after 18 h incubation at $39^{\circ}C$. Monensin was also evaluated as a reference additive under the same conditions. Four species of rumen bacteria were grown in pure culture and exposed to CNSL to determine their morphological sensitivity to the surfactant action of CNSL. Results: CNSL supplementation decreased total gas production in diets with 5:5 and 3:7 F:C ratios, whereas the F:C ratio alone did not affect any gas production. Methane decrease by CNSL addition was more apparent in diets with 5:5, 3:7, and 1:9 F:C ratios. An interactive effect of CNSL and the F:C ratio was also observed for methane production. CNSL supplementation enhanced propionate production, while total SCFA production was not affected. Monensin decreased methane production but only in a diet with a 1:9 F:C ratio with increased propionate. Studies of pure cultures indicated that CNSL damaged the cell surface of hydrogen- and formate-producing bacteria, but did not change that of propionate-producing bacteria. Conclusion: CNSL can selectively inhibit rumen bacteria through its surfactant action to lead fermentation toward less methane and more propionate production. As CNSL is effective over a wider range of dietary conditions for such modulation of rumen fermentation in comparison with monensin, this new additive candidate might be applied to ruminant animals for various production purposes and at various stages.

• Journal of Science and Technology Studies
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• v.7 no.1
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• pp.67-90
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• 2007

Could STS throw another-colored light on the Hwang's Affair, the scientific fraud committed by Hwang Woo-Suk and his research team in Korea? And could analytic tools of STS unfold another meanings which have been overlooked in most of the traditionally social-sciences-oriented analyses? In this essay, I try to answer these questions by analyzing the Hwang's Affair in the view of STS, especially by using some concepts of actor-network theory(ANT): movement, translation and displacement. I want to say that the Hwang's Affair seems to be a part of normal scientific activity, not an abnormal phenomenon, and as an evidence, focus on the similarities of their life styles between "pure/real scientist" Louis Pasteur and "impure/political scientist" Hwang Woo-Suk. I try to mobilize some concepts of ANT, especially movement, and find out why scientists came to move toward the opposed direction on the pure/real-impure/political line. I suggest that there exists "laboratory politics" as the key factor in this bifurcation. My tentative conclusion is that Pasteur can take a position to make his great world, so-called the Pasteurian world, owing to the success of "double movement" in which he treated his laboratory as a fulcrum to lift up the world, but Hwang degrades himself to "ugly scientific politician" due to the loss of the momentum of his movement; Hwang treated his laboratory only as the symbolic resources and in turn failed to solidify material entities, his real political resources, even though he knew the importance of laboratory.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.279-284
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• 2001

This paper reports the purification of myomodulin A (MMA) and myomodulin E (MME) from the sea hare. The central nervous systems of 500 sea hare were extracted in an acidified solvent, after which four HPLC column systems were used to obtain pure peptides, The phasic contraction bioassay using a Mytilus edulis anterior byssus retractor muscle (ABRW) was applied to monitor all collected fractions. The pure peptides were submitted to Edman degradation based automated microsequencing. Mass spectrometry and chemical synthesis confirmed the sequence. The primary structures of MMA and MME were Pro-Met-Ser-Met-Leu-Arg-Leu-$NH_2$, (847.41 Da) and Cly-Leu-Gln-Met-Leu-Arg-Leu-$NH_2$, (830.50 Da), respectively. Synthetic peptides showed a modulating activity of phasic contraction in the ABRM of Mrtilus edulis.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.735-742
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• 2004

This study was conducted for the identification of pure Landrace, Large White and Duroc breeds which are mainly maintained in Korea using DNA markers. We used known KIT and MC1R mutations, which were related coat color in pigs, and pig mitochondrial DNA variations. The KIT mutation was used to distinguish white and colored animals. Duroc breed could be discriminated from other colored breeds using the MC1R mutation N121D. Discriminating Landrace and Large White was possible using the l l-bp duplication of D-Ioop region and alternative initiation codon of ND2. In conclusion, identification of Landrace, Large White and Duroc breeds was might be possible using the procedure designed in this study.

• Food Engineering Progress
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• v.13 no.4
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• pp.275-281
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• 2009

Sesame oils are partially mixed with other vegetable oils due to high price in a Korean market. To find out authentic sesame oil, a mass spectrometer-based electronic nose (MS-based E-nose) was used. Sesame oil (Se) was blended with soybean oil (So) or corn oil (Co) at the ratio (Se:So, Se:Co) of 97:3, 94:6, 91:9, 88:12 and 85:15, respectively. Intensities of each fragment from sesame oil by MS-based E-nose were completely different from those of soybean oil or corn oil. The obtained results were used for discriminant function analysis (DFA). Volatile organic components (VOC) of soybean oil or corn oil were similar to those of fresh air and DFA plot indicated a significant separation of pure sesame oil and pure other oil. The group of the mixed oil was seperated with that of sesame oil in DFA plot and the added amount of soybean oil to sesame oil was correlated with discriminant function first score (DF1). MS based E-nose system could be used as an efficient method to investigate the purity of sesame oil.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1161-1171
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• 2018

Objective: The aim of this study was to investigate diffusion tensor (DT) imaging-derived properties of benign oligemia, true "at risk" penumbra (TP), and the infarct core (IC) during the first 3 hours of stroke onset. Materials and Methods: The study was approved by the local animal care and use committee. DT imaging data were obtained from 14 rats after permanent middle cerebral artery occlusion (pMCAO) using a 7T magnetic resonance scanner (Bruker) in room air. Relative cerebral blood flow and apparent diffusion coefficient (ADC) maps were generated to define oligemia, TP, IC, and normal tissue (NT) every 30 minutes up to 3 hours. Relative fractional anisotropy (rFA), pure anisotropy (rq), diffusion magnitude (rL), ADC (rADC), axial diffusivity (rAD), and radial diffusivity (rRD) values were derived by comparison with the contralateral normal brain. Results: The mean volume of oligemia was $24.7{\pm}14.1mm^3$, that of TP was $81.3{\pm}62.6mm^3$, and that of IC was $123.0{\pm}85.2mm^3$ at 30 minutes after pMCAO. rFA showed an initial paradoxical 10% increase in IC and TP, and declined afterward. The rq, rL, rADC, rAD, and rRD showed an initial discrepant decrease in IC (from -24% to -36%) as compared with TP (from -7% to -13%). Significant differences (p < 0.05) in metrics, except rFA, were found between tissue subtypes in the first 2.5 hours. The rq demonstrated the best overall performance in discriminating TP from IC (accuracy = 92.6%, area under curve = 0.93) and the optimal cutoff value was -33.90%. The metric values for oligemia and NT remained similar at all time points. Conclusion: Benign oligemia is small and remains microstructurally normal under pMCAO. TP and IC show a distinct evolution of DT-derived properties within the first 3 hours of stroke onset, and are thus potentially useful in predicting the fate of ischemic brain.