• Kyungpook Mathematical Journal
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• v.56 no.4
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• pp.1115-1123
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• 2016

Let $D{\subseteq}E$ be an extension of integral domains with characteristic zero, I be a nonzero proper ideal of D and let H(D, E) and H(D, I) (resp., h(D, E) and h(D, I)) be composite Hurwitz series rings (resp., composite Hurwitz polynomial rings). In this paper, we show that H(D, E) satisfies the ascending chain condition on principal ideals if and only if h(D, E) satisfies the ascending chain condition on principal ideals, if and only if ${\bigcap}_{n{\geq}1}a_1{\cdots}a_nE=(0)$ for each infinite sequence $(a_n)_{n{\geq}1}$ consisting of nonzero nonunits of We also prove that H(D, I) satisfies the ascending chain condition on principal ideals if and only if h(D, I) satisfies the ascending chain condition on principal ideals, if and only if D satisfies the ascending chain condition on principal ideals.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.668-674
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• 2020

Manuka honey (MH) has been shown anti-bacterial activity against several pathogenic bacteria. However, the inhibitory effect of MH on biofilm formation by Escherichia coli O157:H7 has not yet been examined. In this study, MH significantly reduced E. coli O157:H7 biofilm. Moreover, pre- and post-treatment with MH also significantly reduced E. coli O157:H7 biofilm. Cellular metabolic activities exhibited that the viability of E. coli O157:H7 biofilm cells was reduced in the presence of MH. Further, colony forming unit of MH-treated E. coli O157:H7 biofilm was significantly reduced by over 70%. Collectively, this study suggests the potential of anti-biofilm properties of MH which could be applied to control E. coli O157:H7.

• East Asian mathematical journal
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• v.33 no.3
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• pp.317-322
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• 2017

Let $D{\subseteq}E$ be an extension of integral domains with characteristic zero, I be a nonzero proper ideal of D, and let H(D, E) and H(D, I) (resp., h(D, E) and h(D, I)) be composite Hurwitz series rings (resp., composite Hurwitz polynomial rings). In this article, we show that H(D, E) is an Archimedean ring if and only if h(D, E) is an Archimedean ring, if and only if ${\bigcap}_{n{\geq}1}d^nE=(0)$ for each nonzero nonunit d in D. We also prove that H(D, I) is an Archimedean ring if and only if h(D, I) is an Archimedean ring, if and only if D is an Archimedean ring.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.118-124
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• 2003

For the rapid detection of various pathogenic microorganisms from food sample, various kinds of kits have been developed and commercially available in the markets. With the advantages of speed, accuracy and easiness, the market of these kits has gradually increased for the QC and QA field of food company as well as testing facilities or laboratories. In this study, the characteristics such as the detection limit and the sensitivity of immunochromatographic type of rapid detection kit (Donga Co, Korea, D-kit) for E. coli 0157:H7 developed by monoclonal antibody were examined and also the possibility of application of the kit to food samples was evaluated. The reference kits used for comparison study were Reveal E. coli 0157:H7 (Neogen Co., USA, R-kit) and VIP EHEC kit (Biocontrol Inc., USA, V-kit) occupying major market share. In the detection limit test with the E. coli 0157:H7 reference, both R-kit and D-kit showed a distinct positive reaction in $10^4$/ml and weak positive reaction in $10^3$/ml, whereas V-kit showed a same reaction in 105/ml. Also, it was identified that the culture treated with heat showed more sensitivity than no heat treated culture. The sensitivity test was conducted against 22 isolates of E. coli 0157:H7, 7 strains of non-O157:H7 verotoxin-producing E. coli, 40 strains of E. coli with different O and H antigen type, and 38 strains of non-E. coli Enterobacteriaceae, and all of the test strains except three were showed exactly three were showed exactly the same reaction against three kinds of the tested kits. All the three kinds of kits showed a positive reaction against E. coli O157:H19, E. coli O148:H18 and Salmonella galinarium. We suppose that there might be a similarity in serological property between these three strains and O157:H7. From the test results, it can be concluded that there is (was) no difference between the D-kit developed in this study and R-kit or V-kit based on the detection limit and sensitivity.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.217-224
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• 1999

This Paper shows the results of a series of model tests on the behavior of single rigid Pile, which subjected to lateral load, in non-homogeneous Nak-Dong River sands, consisted of two layers, upper and lower layers. The purpose of the present paper is to investigate the effect of ratio of lower layer thickness to embedded pile length ratio of soil modules of upper to lower layer (E$\sub$h1//E$\sub$h2/) and pile head constraint condition on the characteristics of lateral behavior of single pile. These effects can be quantified only by the results of model tests. As a model test result, in non-homogeneous sand, it shows that the lateral behavior depends upon the ratio of soil modules of upper to lower layer more than other factors. And, in respect of deflection, it was found that the reduction ratio of deflection by pile head fixity is the value of 0.5 and 0.6 for E$\sub$h1//E$\sub$h2/=0.18 and E$\sub$h1//E$\sub$h2/=5.56, respectively. The critical thickness of lower layer on the change of deflection is about 25 - 50% of pile embedded length. Also, in respect of maximum bending moment it was found that the reduction ratio of maximum bending moment by pile head fixity is the value of 0.55 and 0.7 for E$\sub$h1//E$\sub$h2/=0.18 and E$\sub$h1//E$\sub$h2/=5.56, respectively.

• Honam Mathematical Journal
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• v.34 no.3
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• pp.409-422
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• 2012

Let $\mathcal{L}$ be a subspace lattice on a Hilbert space $\mathcal{H}$. And let X and Y be operators acting on a Hilbert space $\mathcal{H}$. Let $sp(x)=\{{\alpha}x\;:\;{\alpha}{\in}\mathcal{C}\}$ $x{\in}\mathcal{H}$. Assume that $\mathcal{H}=\overline{range\;X}{\oplus}sp(h)$ for some $h{\in}\mathcal{H}$ and < $h$, $E^{\bot}Xf$ >= 0 for each $f{\in}\mathcal{H}$ and $E{\in}\mathcal{L}$. Then there exists an operator A in Alg$\mathcal{L}$ such that AX = Y if and only if $sup\{\frac{{\parallel}E^{\bot}Yf{\parallel}}{{\parallel}E^{\bot}Yf{\parallel}}\;:\;f{\in}H,\;E{\in}\mathcal{L}\}$ = K < ${\infty}$. Moreover, if the necessary condition holds, then we may choose an operator A such that AX = Y and ${\parallel}||A{\parallel}=K$.

• BMB Reports
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• v.35 no.6
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• pp.547-552
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• 2002

The aim of our study was to investigate the protective effects of intraperitoneally-administrated vitamin E, dl-alpha lipoic acid, and linalool on the level of total lipid and fatty acid in guinea pig brains with oxidative stress that was induced by $H_2O_2$. The total brain lipid content in the $H_2O_2$ group decreased when compared to the $H_2O_2$ + vitamin E (p<0.05), $H_2O_2$ + linalool (p<0.05), ALA (p<0.05), control (p<0.01), linalool (p<0.01), and vitamin E (p<0.01) groups. While the proportion of total saturated fatty acid (${\Sigma}SFA$) in the $H_2O_2$ group significantly increased (p<0.005) when compared to the vitamin E group, it only slightly increased (p<0.01) when compared to the control and $H_2O_2$ + vitamin E groups. The ratio of the total unsaturated fatty acid (${\Sigma}USFA$) in the $H_2O_2$ groups was lower (p<0.05) than the control, vitamin E, and $H_2O_2$ + vitamin E groups. The level of the total polyunsaturated fatty acid (${\Sigma}PUEA$) in the $H_2O_2$ group decreased in when compared to the control, vitamin E, and $H_2O_2$ + vitamin E groups. While the proportion of the total w3 (omega 3), w6 (omega 6), and PUFA were found to be lowest in the $H_2O_2$ group, they were slightly increased (p<0.05) in the lipoic acid group when compared to the control and $H_2O_2$ + lipoic acid groups. However, the level of ${\Sigma}SFA$ in the $H_2O_2$ group was highest; the level of ${\Sigma}USFA$ in same group was lowest. As the proportion of ${\Sigma}USFA$ and ${\Sigma}PUFA$ were found to be highest in the linalool group, they were decreased in the $H_2O_2$ group when compared to the control group. Our results show that linalool has antioxidant properties, much the same as vitamin E and lipoic acid, to prevent lipid peroxidation. Additionally, vitamin E, lipoic acid, and linalool could lead to therapeutic approaches for limiting damage from oxidation reaction in unsaturated fatty acids, as well as for complementing existing therapy for the treatment of complications of oxidative damage.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.283-292
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• 2009

Objective: Human embryonic stem cells (hESCs) can proliferate indefinitely and differentiate into all kinds of cell types in vitro. Therefore, hESCs can be used as a cell source for cell-based therapy. Transduction of foreign genes to hESCs could be useful for tracing differentiation processes of hESCs and elucidation of gene function. Thus, we tried to introduce enhanced green fluorescent protein (eGFP) gene to hESCs, XX and XY cell lines in this study. Methods: Lentivirus containing eGFP was packaged in 293T cells and applied to hESCs to transduce eGFP. Expression of transduced eGFP was evaluated under the fluorescence microscope and eGFP positive population was analyzed by FACS. Expression of undifferentiation state markers such as Oct4, Nanog, SSEA4 and Tra-1-81 was examined by RT-PCR and/or immunofluorescence in eGFP-hESCs after transduction. In addition, the ability of eGFP-hESCs to form embryoid bodies (EBs) was tested. Results: eGFP was successfully transduced to hESCs by lentivirus. eGFP expression was stably maintained up to more than 40 passages. eGFP-hESCs retained expression patterns of undifferentiation state markers after transduction. Interestingly, disappearance of transduced eGFP was notably observed during spontaneous differentiation of eGFP-hESCs. Conclusion: We established eGFP expressing hESC lines using lentivirus and showed the maintenance of undifferentiation characteristics of these eGFP-hESCs. This reporter-containing hESCs could be useful for tracing the processes of differentiation of hESCs and other studies.

• Bulletin of the Korean Mathematical Society
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• v.31 no.2
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• pp.193-200
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• 1994

Let x : $M^{n}$ .rarw. $E^{m}$ be an isometric immersion of a manifold $M^{n}$ into the Euclidean space $E^{m}$ and .DELTA. the Laplacian of $M^{n}$ defined by -div.omicron.grad. The family of such immersions satisfying the condition .DELTA.x = .lambda.x, .lambda..mem.R, is characterized by a well known result ot Takahashi (8]): they are either minimal in $E^{m}$ or minimal in some Euclidean hypersphere. As a generalization of Takahashi's result, many authors ([3,6,7]) studied the hypersurfaces $M^{n}$ in $E^{n+1}$ satisfying .DELTA.x = Ax + b, where A is a square matrix and b is a vector in $E^{n+1}$, and they proved independently that such hypersurfaces are either minimal in $E^{n+1}$ or hyperspheres or spherical cylinders. Since .DELTA.x = -nH, the submanifolds mentioned above satisfy .DELTA.H = .lambda.H or .DELTA.H = AH, where H is the mean curvature vector field of M. And the family of hypersurfaces satisfying .DELTA.H = .lambda.H was explored for some cases in [4]. In this paper, we classify space curves x : R .rarw. $E^{3}$ satisfying .DELTA.x = Ax + b or .DELTA.H = AH, and find conditions for such curves to be equivalent.alent.alent.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1665-1670
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• 2006

The objective of this research was to provide the characterization and method for producing anti-E. coli O157:H7 antibodies in egg-laying hens and to determine if the antibody can restrain the proliferation of E. coli O157:H7 in-vitro. Selected antigenic fractions (whole cell, outer membrane protein and lipopolysaccharide (LPS)) from E. coli O157:H7 were injected to hens in order to produce anti-E. coli O157:H7 antibodies. The immune response and the egg yolk antibodies of laying hens against the whole cell, outer membrane protein and LPS antigens were monitored by ELISA. The level of antibodies against whole cell antigen monitored through ELISA sharply increased after the initial immunization, and it was found to be maximum on day 49 however, the level was maintained up to day 70. Antibodies (5 mg/ml) directed against the whole cell inhibited E. coli proliferation 10-13 times more than outer membrane protein or LPS. The antibody response against the whole cell antigens appeared to have higher activity in restraining the proliferation of E. coli O157:H7 than antibody against outer membrane protein or LPS. Results reflected that increasing the IgY's in the egg yolk could prevent greater economic losses due to human and animal health from pathogenic bacteria i.e. E. coli O157:H7.