• Korean Journal of Microbiology
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• v.27 no.3
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• pp.188-193
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• 1989

Gene for lactose catabolism in Lactobacillus casei SW-M1 was encoded by a 60Kb metabolic plasmid. A derivative of only 10kb, pPlac 15 of recombinant plasmid, was constructed by introducing into pBR322 and was cloned into E. coli using restriction endonuclease Pst I. A 10kb insery DNA in plasmid pBR322 was identified as a gene encoded phospho-$\beta$-galactosidase by the determination of enzyme activity. Phospho-$\beta$-galactosidase was apparently expressed in E. coli. The enzyme activities of cell-free extract from transformant E. coli HB101 carrying pPLac 15 DNA were not different from that of L. casei as a donor strain on the basis of enzyme properites. However, specific activity of phospho-$\beta$-galactosidase in the cloned strain with Lac $Y^{-}$ phenotype of E. coli HB101 was lower than that in L. casei strain.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.04a
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• pp.65-69
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• 1990

The elastic analysis of floor slabs using the p-version of finite element method encounters stress singularities at certain types of reentrant corners, openings and cut-outs. Results obtained using the computer code based on C$\^$o/-hierarchic plate element formulated by Reissner-Mindlin theory are compared with theoretical predictions and with computational results reported in the literature. The convergence rate of h-, p- and hp-version can be estimated on the basis of the energy norm in global sense. If accuracy in terns of the number of degrees-of-freedom is used as a criterion, the solutions presented here are the most efficient that have been published up to date. Examples are the rhombic plate with the obtuse angle of 150o and the square plate with cut-outs.

• Bulletin of the Korean Chemical Society
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• v.16 no.12
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• pp.1176-1179
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• 1995

1H NMR spectra of pyridine, α-, β-, and γ-picoline coordinated to the paramagnetic heteropolyanion [Ni3(PW9O34)2]12- (P2Ni3) are reported. NMR lines are assigned to [Ni3(ptl)n(PW9O34)2]12- (n=1, 2 or 3; ptl=pyridine-type ligand) on the basis of their [P2Ni3]/[ptl] dependence. The formation constants for γ-picoline complexes at 25 ℃ are K1=80, K2=610, and K3=190 L mol-1. The monopicoline complex has greater affinity for γ-picoline than P2Ni3. A degradation product, [Ni2(WO2)(PW9O34)2]12-, was also identified at low pH by measuring the NMR spectrum of pyridine coordinated to it. The isotropic NMR shifts come mainly from the contact interaction due to σ-electron delocalization.

• Bulletin of the Korean Chemical Society
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• v.5 no.5
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• pp.175-178
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• 1984

Two series of membranes have been prepared by postcrosslinking highly syndiotactic and isotactic poly (2-hydroxyethyl methacrylate), P(HEMA). The crosslinker used was hexamethylene diisocyante (HMDIC). The distribution coefficients (K$_{D2}$) of the model solutes such as urea (and thiourea), their derivatives, homologous alcohol series and amide sreies in water-swollen tactic P(HEMA) membranes at $25^{\circ}C$ were mesaured. In addition, the concentration effects of acetamide and butyramid were also measured. On the basis of hydrophobic interaction and the structural factors of tactic P(HEMA) membranes, the hydrophobic adsorption of the solutes in the polymer matrix were discussed. The results showed that the more hydrphobic the solute is, the higher the $K_{D2}$ value is. And the polymer conformation also affects the distribution of solvents.

• Bulletin of the Korean Mathematical Society
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• v.61 no.4
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• pp.907-915
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• 2024

Let f be an integral quadratic form in k variables, F the Gram matrix corresponding to a ℤ-basis of ℤ^k. For r ∈ F^-1ℤ^k, a rational number n with f(r) ≡ n mod ℤ and a positive integer c, set N_f(n, r; c) := #{x ∈ ℤ^k/cℤ^k : f(x + r) ≡ n mod c}. Siegel showed that for each prime p, there is a number w depending on r and n such that N_f(n, r; p^ν+1) = p^k-1N_f(n, r; p^ν) holds for every integer ν > w and gave a rough estimation on the upper bound for such w. In this short note, we give a more explicit estimation on this bound than Siegel's.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.1
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• pp.31-38
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• 2013

Patients with heart disease need long-term monitoring of the electrocardiogram (ECG) signal using a portable electrocardiograph. This trend requires the miniaturization of data storage and faster transmission to medical doctors for diagnosis. The ECG signal needs to be utilized for efficient storage, processing and transmission, and its data must contain the important components for diagnosis, such as the P wave, QRS-complex, and T wave. In this study, we select the vertex which has a larger curvature value than the threshold value for compression. Then, we reconstruct the compressed signal using by radial basis function interpolation. This technique guarantees a lower percentage of root mean square difference with respect to the extracted sample points and preserves all the important features of the ECG signal. Its effectiveness has been demonstrated in the experiment using the Massachusetts Institute of Technology and Boston's Beth Israel Hospital arrhythmia database.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.9-15
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• 1998

The geometrical parameters, vibrational frequencies, and IR intensities of dimethyldioxirane had been investigated using high level ab initio quantum mechanical methods with various basis sets. The polarization function decreases C-O and C-C bond distances significantly and the electron correlation effect increases those bond lengths slightly, while other bond lengths and bond angles are relatively stable for basis set size and correlation effect. The experimental and other theoretical vibrational frequencies and IR intensities of dimethyldioxirane will be compared and discussed with our high level theoretical predictions.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2806-2808
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• 2010

The structure of 3-aminophenol $(CO_2)_1$ cluster was computationally studied both in the ground and the lowest singlet excited electronic states. The ground state structure and binding energy of the cluster was investigated using the second-order M$\ddoot{o}$ller-Plesset perturbation theory (MP2) at the complete basis set (CBS) limit. The excited state geometry of the cluster was obtained at the second-order approximate coupled cluster (CC2) level with cc-pVDZ basis set, and the $S_0-S_1$ absorption spectrum was simulated by calculating Franck-Condon overlap integral. The ground state geometry of the global minimum with a very high binding energy of 4.3 kcal/mol was found for the cluster, due to the interaction between amino group and $CO_2$ in addition to the strong $\pi-\pi$ interaction between the aromatic ring and $CO_2$. The excited state geometry shows a very big shift in the position of $CO_2$ compared to the ground state geometry, which results in low intensity and broad envelope in the Franck-Condon simulation.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.354-357
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• 2009

Three compounds, vanillic acid, p-hydroxylcinnamic acid, p-hydroxybenzaldehyde have been isolated from the ethylacetate extract of Sparganium stoloniferum Buch.-Ham roots using silica gel open column chromatography, preparative thin-layer chromatography (pTLC) and reverse phase high performance liquid chromatography. The structures of the compounds were established on the basis of IR, extensive 1D NMR, and MS analyses. The ethylacetate (EtOAc) extract, vanillic acid, and p-hydroxybenzaldehyde showed $\alpha$-glucosidase inhibition activity of 72.71%, 20.13%, and 30.42%, at the concentration of 10 ${\mu}g/mL$, respectively. The EtOAc extract exhibited strong antioxidant activity with an $IC_50$ value of 24.37 ${\mu}g/mL$ against DPPH radical scavenging activity, the vanillic acid, p-hydroxylcinnamic acid, and p-hydroxybenzaldehyde with an $IC_50$ value of 2.10 ${\mu}M$, 1.59 ${\mu}M$, and 2.72 ${\mu}M$ against DPPH, respectively.

• Computational Structural Engineering
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• v.6 no.4
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• pp.57-66
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• 1993

The p-version crack model based on integrals of Legendre polynomial and virtual crack extension method is proposed with its potential for application to stress intensity factor computations in linear elastic fracture mechanics. The main advantage of this model is that the data preparation effort is minimal because only a small number of elements are used and high accuracy and the rapid convergence can be achieved in the vicinity of crack tip. There are two important findings from this study. Firstly, the limit value, the strain energy of the exact solution, can be estimated with successive three p-version approximations by ascertaining that the approximations enter the asymptotic range. Secondly, the rate of convergence of p-version model is almost twice that of h-version model on the basis of uniform or quasiuniform mesh refinement for the cracked panel problem subjected to tension.