• Journal of Microbiology
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• v.33 no.3
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• pp.178-183
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• 1995

The recombinant plasmid of pCU103 constructed by cloning pcbCD genes in pBluescript SK(+) was studied for the effect of temperature on its persistence in different waters by the methods of electrophoresis, Southern hybridization, quantification, and transformation. The plasmid was very rapidly degraded out in non-sterile FW water without regards to water temperature, probably due to the effect of biochemical factor such as nucleases. The pCU103 was most persistent at 4$^{\circ}C$ in any water environments, moderately persistant at 15$^{\circ}C$ but least stable at 3$0^{\circ}C$ such results could be explained by the facts that hydrogen bonds in double-stranded plasmid DNAs become unstable and that nucleases are activated by increasing temperature. The intact structure of pCU1-3 was generally observed by gel electrophoresis under the conditions which the plasmid should be 2.0 ng/$\mu\textrm{l}$ or higher in concentration and that about 10$^2$ CFU/ml or more transformant cells should be recovered.

• The Korean Journal of Ecology
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• v.18 no.1
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• pp.109-120
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• 1995

As the genetically modified microorganisms (GMMs) and their recombinant plasmid DNAs could be released into natural environments, their stabilities and impacts to indigenous microorganisls have become very importhant research subjects concerning with environmental and ecological aspects. In this study, the genetically modified E. coli CU103 and its recombinant pCU103 plasmid DNA, in which pcbCD genes involving in degradation of biphenyl and 4-chlorobiphenyl were cloned, were studied for their survival and stability in several different waters established under laboratory conditions. E. coli CU103 and its host E. coli XL1-Blue survived longer in sterile distilled water (SDW) and filtered autoclaved river water (FAW) than in filtered river water (FW). A lot of extracellular DNAs were released from E. coli CU103 by lytic action of phages in FW and the released DNAs were degraded by DNase dissolved in the water. Such effects of the factors in FW on stability of the recombinant pCU103 plasmid were also observed in the results of gel electrophoresis, quantitative analysis with bisbenzimide, and transformation assay. Therefore, the recombinant plasmids of pCU103 were found to be readily liberated from the genetically modified E. coli CU103 into waters by normal metabolic processes and lysis of cells. And the plasmid DNAs were quite stable in waters, but their stabilities could be affected by physicoKDICical and biological factors in non-sterile natural waters.

• Journal of Microbiology
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• v.34 no.3
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• pp.241-247
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• 1996

The stability of the genetically engineered microorganisms and their recombinant plasmids released in natural environments has been regarded as one of the molecular ecological topics. In this study, the recombinant plasmids pCU103 in which the pcbCD genes involved in biodegradation of biphenyl and 4-chlorobiphenyl were cloned in pBluescript SK(+) vector, were examined for their structural and functional stability in different waters at 15 $^{\circ}C$ by the methods of electrophoresis, Southern hybridization, quantification with fluorescent dye, and transformation. The recombinant plamids maintained their stabilities for about 30 days in sterilized distilled water (SDW), 15 days in autoclaved creek water (AW), 25 days in filtered and autoclaved non-sterile creek water (FAW), 4 days in Luria-Bertani (LB) broth, and less than one day in filtered non-sterile creek water (FW). The covalently closed circular (CCC) form of the plasmid was decreased and open circular (OC) form was increased as a function of incubation time, and then linear (L) form was produced to be ultimately degraded out. The degradation rates of the plasmid were proportionally correlated to trophic level of the water, and the biological factor such as DNases was found to be one of the most critical factors affecting structural and functional stability of the plasmid in non-sterile natural water.

• Journal of the Korean institute of surface engineering
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• v.24 no.2
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• pp.103-113
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• 1991

Electroless Ni-Cu-P alloy plating of Al base hard disk was performed to investigate some properties according to the change of composition. It was found that the composition of Ni and Cu in deposits changed linearly with increasing the mole ratio of NiSO4.6H2O/CuSO4.5H2O. The increase in hardness by heat - treatment was confirmed to be associated with small size grained crystallization of the amorphous deposits. Acid resistance of all deposits layer. which had been heated up to 30$0^{\circ}C$, was found to be exellent when immersed in 1N-H2SO4 solution, and it showed more superior acid resistance with decreasing Cu content and with increasing P. The resistivity of the deposits heat treated became smaller at temperature more than 50$0^{\circ}C$, and it became largerly with increasing P content. Cu 44.1wt% alloy(C bath) showed the most superior non-magnetically stable characteristics after heat treatment. It was superiorly with higher temperature and with decreasing P content.

• Proceedings of the Zoological Society Korea Conference
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• 1994.10a
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• pp.120.1-120
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• 1994

• Journal of Microbiology
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• v.34 no.3
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• pp.248-254
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• 1996

$cdc103^+$ gene in Schizosaccharomyces pombe which is similar to the CDC3 gene in Saccharomyces cerevisiae was cloned and sequenced. Comparison of the predicted amino acid sequences of $cdc103^+$ and CDC3 revealed that they share significant similarity (43% identity and 56% identity or similarity) to each other. The gene product of CDC3 in S. cerevisiae is known to be a highly ordered ring of filaments that lies just inside the cytoplasmic membrane in the region of the mother-bud neck. In order to characterize the gene product of $cdc103^+$ in Schizosaccharomyces pombe, fusion proteins were used to generate the polyclonal antibodies specific for the gene product (cdc103p). In immunofluorescence experiments, these antibodies decorate the region of the septum formation as a double ring structure late in the cell division cycle.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.161.2-161
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• 1995

No Abstract, See Full Text

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1154-1161
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• 2000

Two experiments were conducted to evaluate the efficacy of cupric citrate (Cu-citrate) relative to cupric sulfate $(CuSO_4)$ as a Cu source for weanling and grow-finish pigs. In addition, the use of liver and bile Cu concentrations as indices of the bioavailability of Cu sources was investigated. Experiment one consisted of a nursery phase (35 d; initial BW=6.4 kg, final BW=21.4 kg) followed by a grow-finish phase (103 d; initial BW=21.5 kg, final BW=111.7 kg). Experiment two only consisted of a nursery phase (35 d; initial BW=6.3 kg, final BW=18.6 kg). Dietary treatments were identical for both experiments and consisted of: control (10 ppm $CuSO_4$); control+66 or 225 ppm $CuSO_4$; control+33, 66, or 100 ppm Cu-citrate. An antibiotic was included in diets for Exp. 1 but not Exp. 2. In both experiments, growth performance variables were similar for pigs receiving Cu-citrate and $CuSO_4$; however, growth performance was not improved by high concentrations of $CuSO_4$. Liver and bile Cu were increased (p<0.05) by 225 ppm $CuSO_4$; however, lower dietary concentrations of Cu from either $CuSO_4$ or Cu-citrate did not affect the Cu concentration of liver or bile relative to that observed in the control pigs. Irrespective of Cu source, there was no linear (p>0.10) increase in plasma Cu with increasing Cu concentrations in the diet for both experiments. However, the plasma Cu concentrations were highest (p<0.10) in pigs receiving diets supplemented with 225 ppm $CuSO_4$. Sixteen randomly chosen pigs per treatment in Exp. 1 were continued through the grow-finish phase. Body weight gain and feed intake were improved (p<0.10) by 66 ppm $CuSO_4$, but other dietary Cu treatments did not alter pig performance compared to the control diet. Plasma Cu concentrations were increased (p<0.10) by 225 ppm $CuSO_4$ in the growing phase and by 225 ppm $CuSO_4$ and 100 ppm Cu-citrate in the finishing phase. These data reveal no consistent effect of $CuSO_4$ on performance; therefore, it is difficult to assess the efficacy of these two Cu sources. In addition, these studies demonstrate that liver and bile Cu are not good indicators of Cu bioavailability in pigs fed adequate to pharmacological concentrations of Cu.

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.132-137
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• 1997

The crystal structure of N,N'-di-tert-butoxycabonyl-2,7-diazabicyclo[3.3.0]oct-4-ene has been determined from single crystal x-ray diffraction study; C16H26N2O4, Triclinic, P1, a=11.119(1) Å, b=13.638(1) Å, c=6.214(1) Å, α=92.14(1)°, β=103.49(1)°, γ=73.35(1)°, V=877.4(2)Å3, T=293(2)K, Z=2, CuKα(λ=1.5418Å). The structure was solved by direct method and refined by full-matrix least squares to a final R=5.38% for 2389 unique observed F0>4σ(F0) reflections and 225 parameters.

• Journal of Magnetics
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• v.15 no.3
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• pp.103-107
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• 2010

We investigated spin-polarized current switching of Pac-man type II (PM-II) nanoelements in Pac-man shaped nanoscale spin-valves (Co/Cu/Py) using micromagnetic simulations. The effects of slot angle and antiferromagnetic (AFM) layer were simulated to obtain optimum switching in less than 2 ns. At a critical slot angle of $105^{\circ}$, the lowest current density for anti-parallel to parallel (AP-P) switching was observed due to no vortex or antivortex formation during the magnetic reversal process. All other slot angles for AP-P formed a vortex or antivortex during the magnetization reversal process. Additionally, a vortex or anti-vortex formed for all slot angles for parallel to anti-parallel (P-AP) switching. The addition of an AFM layer caused the current density to decrease significantly for AP-P and P-AP at slot angles less than $90^{\circ}$. However, at slot angles greater than $90^{\circ}$, the current density tended to decrease by less amounts or actually increased slightly as shape anisotropy became more dominant. This allowed ultra-fast switching with 5.05 and $5.65{\times}10^8\;A/cm^2$ current densities for AP-P and P-AP, respectively, at a slot angle of $105^{\circ}$.