• Food Engineering Progress
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• v.14 no.1
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• pp.35-40
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• 2010

Electronic nose (E-nose) was assessed for grading pungency of powdered red pepper. Complex pretreatments are not required for flavor analysis unlike HPLC or Scoville tests. Mild and pungent taste of powdered red pepper were mixed at various concentrations of 0, 25, 50, 75, and 100%. Those were analyzed using mass spectrometer-based E-nose. Discriminant function analysis (DFA) was conducted on E-nose data. The $R^{2}$ and F-value of dicriminant function first score (DF1) were 0.9946 and 355.65, respectively, when the samples were separated by a relative degree of pungent taste. DF1 value decreased with increasing the amount of powdered red pepper with a pungent taste. It is similar to the increase in the concentration of capsaicin. Increasing the amount of red pepper powder, dicriminant function second score (DF2) values were moved from the negative position into the positive position. The $R^{2}$ and F-value of DF1 were 0.9890, 165.17 and DF2 were 0.9219, 21.64. Also, the results by MS based E-nose agreed to that by HPLC. There is the potential to grade pungent taste of powdered red pepper using the E-nose.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.159.1-159.1
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• 2000

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.194-201
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• 1995

In order to make clear the resistance of bag nets, the resistance R of bag nets with wall area S designed in pyramid shape was measured in a circulating water tank with control of flow velocity v and the coefficient k in $R=kSv^2$ was investigated. The coefficient k showed no change In the nets designed in regular pyramid shape when their mouths were attached alternately to the circular and square frames, because their shape in water became a circular cone in the circular frame and equal to the cone with the exception of the vicinity of frame in the square one. On the other hand, a net designed in right pyramid shape and then attached to a rectangular frame showed an elliptic cone with the exception of the vicinity of frame in water, but produced no significant difference in value of k in comparison with that making a circular cone in water. In the nets making a circular cone in water, k was higher in nets with larger d/l, ratio of diameter d to length I of bars, and decreased as the ratio S/S_m$ of S to the area $S_m$ of net mouth was increased or as the attack angle 9 of net to the water flow was decreased. But the value of ks15m was almost constant in the region of S/S_m=1-4$ or $\theta=15-90^{\circ}$ and in creased linearly in S/S_m>4 or in $\theta<15^{\circ}$ However, these variation of k could be summarized by the equation obtained in the previous paper. That is, the coefficient $k(kg\;\cdot\;sec^2/m^4)$ of bag nets was expressed as $$k=160R_e\;^{-01}(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for the condition of $R_e<100$ and $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for $R_e\geq100$, where $S_n$ is their total area projected to the plane perpendicular to the water flow and $R_e$ the Reynolds' number on which the representative size was taken by the value of $\lambda$ defined as $$\lambda={\frac{\pi d^2}{21\;sin\;2\varphi}$$ where If is the angle between two adjacent bars, d the diameter of bars, and 21 the mesh size. Conclusively, it is clarified that the coefficient k obtained in the previous paper agrees with the experimental results for bag nets.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1529-1534
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• 2003

The effects of dietary vitamin E supplementation (control; 200 IU/head/day, 500 IU/head/day and 1,000 IU/head/day) on color stability, lipid oxidation and total reducing ability in M. longissimus and M. semimembranosus from Hanwoo (Korean cattle) steer during retail display ($3{\pm}1^{\circ}C$, 1,200 lux) were investigated. The $L^{*}$, $a^{*}$, $b^{*}$, $C^{*}$, R630-R580 values and TRA (total reducing ability) of 1,000 IU group were significantly (p<0.05) higher than those of the other groups. The $a^{*}$, $C^{*}$, R630-R580 and TBARS values were significantly (p<0.05) higher in M. longissimus than in M. semimembranosus. The $a^{*}$, $C^{*}$, R630-R580 values and TRA for two beef muscles declined gradually during storage and the decline was more rapid in control and 500 IU groups. Hue angle and metmyoglobin (%) for two beef muscles increased (p<0.05) as display time increased, and 1,000 IU group had a lower rate of metmyoglobin accumulation during retail display. The TBARS values for two beef muscle were significantly (p<0.05) lower in 1,000 IU group than in the other groups over time. Consequently, the meat from 1,000 IU vitamin E-supplemented Hanwoo steer extended retail display life compared to the control and 500 IU/head/day.

• Bulletin of the Korean Mathematical Society
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• v.31 no.1
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• pp.105-113
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• 1994

In the course of study of dendroids, Czuba [3] introduced a notion of $R^{i}$ -continua which is a generalization of R-arc [1]. He showed a new class of non-contractible dendroids, namely of dendroids which contain an $R^{i}$ -continuum. Subsecequently Charatonik [2] attempted to extend the notion into hyperspace C(X) of metric continuum X. In so doing, there were some oversights in extending some of the results relating $R^{i}$ -continua of dendroids for metric continua. In fact, Proposition 1 in [2] is false (see example C below) and his proof of Theorem 6 in [2] is not correct (Take Example 4 in [4] with K = [e,e'] as an $R^{1}$-continuum of X and work it out. Then one seens that K not .mem. K as he claimed otherwise.). The aims of this paper are to introduce a notion of w-regular convergence which is weaker than 0-regular convergence and to prove that the w-regular convergence of a sequence {Xn}$^{\infty}$$_{n=1}$ to $X_{0}$ of subcontinua of a metric continuum X is a necessary and sufficient for the sequence {C( $X_{n}$)}$^{\infty}$$_{n=1}$ to converge to C( $X_{0}$ ), and also to prove that if a metric continuum X contains an $R^{i}$ -continuum with w-regular convergence, then the hyperspace C(X) of X contains $R^{i}$ -continuum.inuum.uum.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.9-12
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• 1985

As a part of the host cell development for a amplified recombinant trp operon, $aroP^-$ mutation was introduced in a E. coli host strain. $aroP^-$ mutation was induced by transposon Tn10 and transduced into the E. coli host cell by bacteriophage P1Kc. The effect of $aroP^-$ mutation on the excretion of tryptophan in E. coli $trpR^{-ts}/ColE_1 -trp^+$ cells was investigated. Mutant lacking the general aromatic transport system was resistant to ${\beta}-2-thienylalanine\;(2{\times}10^{-4}\;M)$, p-fluorophenylalanine $(2{\times}10^{-4}M)$, or 5-methyltryptophan $(2{\times}10^{-4}\;M.)[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain was reduced considerably as compared with $aroP^+$ counterpart. The rate of $[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain treated with $NaN_3(3{\times}10^{-2}\;M)$ was much less affected than that of $aroP^+$ counterpart. The $aroP^-$ transductants increased the tryptophan excretion from E. coli $trpR^{-ts}/ColE_1 -trp^+$ four times more than $aroP^+$ counterpart.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.239-245
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• 2009

Translation initiation factor eIF1A performs essential functions in various initiation steps including 43S preinitiation complex formation in eukaryotes, and contains a highly conserved oligonucleotide-binding (OB) fold. In our previous study, we discovered that eIF1A possesses RNA annealing activity and forms a stable complex with double-stranded RNA. In this study, we initiated site-directed mutations in eIF1A to find the active sites for these biochemical activities and to investigate whether they are essential functions for yeast cell growth. A truncated protein, eIF1A($\Delta$T), devoid of both N- and C-terminal domains but containing an intact OB-fold exhibited RNA annealing activity. In contrast, all point mutations in OB-fold domain, except R57D, impaired both RNA annealing and dsRNA binding activities, indicating that the intact OB-fold domain is required for both activities. Viabilities of the mutant yeast cells were not correlated with RNA annealing activity but with the in vivo protein stabilities in the case of R57D and K94D.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.130-138
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• 2005

This experiment was designed to investigate the effect of Phellodendron amurense(PLDA) on the Alzheimer's disease. The effects of PLDA extract on $IL-1{\beta}$, IL-6, amyloid precursor proteins(APP), acetylcholinesterase(AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 cell treated by $A{\beta}$ plus $rIL-1{\beta}$ and AChE activity of PC-12 cell lysate treated by $A{\beta}$ plus $rIL-1{\beta}$ and behavior of memory deficit mice induced by scopolamine and mice glucose, uric acid, AChE activity of memory deficit rats induced by scopolamine were investigated, respectively. PLDA extract suppressed $IL-1{\beta}$, IL-6, APP, AChE, GFAP mRNA in PC-12 cell treated by $A{\beta}$ plus $rIL-1{\beta}$ ; AChE activity in cell lysate of PC-12 cell treated by $A{\beta}$ plus $rIL-1{\beta}$. PLDA extract increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit rats induced by scopolamine. PLDA extract group showed significantly inhibitory effect on the memory deficit of mice induced by scopolamine in the experiment of Morris water maze. According to the above results, it is suggested that PLDA extract might be usefully applied for prevention and treatment of Alzheimer's disease.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2143-2147
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• 2014

Ketene-forming elimination from 2-X-4-nitrophenyl furylacetates (1a-d) promoted by $R_2NH-R_2NH_2{^+}$ in 70 mol % MeCN(aq) has been studied kinetically. When X = Cl and $NO_2$, the reactions exhibited second-order kinetics as well as Br$\ddot{o}$nsted ${\beta}$ = 0.37-0.54 and $|{\beta}_{lg}|$ = 0.31-0.45. The Br$\ddot{o}$nsted ${\beta}$ decreased with a poorer leaving group and $|{\beta}_{lg}|$ increased with a weaker base. The results are consistent with an E2 mechanism. When the leaving group was changed to a poorer one [X= H (1a) and $OCH_3$ (1b)], the reaction mechanism changed to the competing E2 and E1cb mechanisms. A further change to the E1cb mechanism was realized for the reaction of 1a with $i-Pr_2NH/i-Pr_2NH_2{^+}$ in 70 mol % MeCN-30 mol % $D_2O$. By comparing the kinetic results in this study with the existing data for $ArCH_2C(O)OC_6H_3-2-X-4-NO_2$, the effect of the ${\beta}$-aryl group on the ketene-forming elimination was assessed.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.1-6
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• 2004

This study was conducted to investigate novel genetic variations of MCIR^*3 allele. In general, white spotting or white belt on a black backgroud in pigs is determined by the E$^p$ allele at the MCIR/Extention locus. E$^p$ shares a frameshift mutation with the E$^{D2}$ allele for dominant black color. An oligonucleotide primer set was designed to amplify complete coding sequence of the porcine MCIR gene. The MCIR coding sequences obtained from five breeds those were Landrace(white). Yorkshire(white), Hampshire(belt), Berkshire(spot) and Jeju native black pigs(black), were used for this study. A multiple sequence alignment of the MCIR coding region using Clustal W was performed. The total length of the MCIR coding sequence ranged from 963 to 966 base pairs(bp) among the selected breeds. The sequence analysis of the complete coding region of MCIR was revealed that Hampshire and Jeju native black pig have 3 cytosines deletion and Birkshire has 2 cytosines deletion at codon 23(nt68) in Extention loci. Besides the finding, there were three different missense mutations and a frameshift mutation in the MCIR coding region.