• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.432-436
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• 2014

While searching for healthier diets, people became more attentive to agricultural organic products. However, organic foods may be more susceptible to microbiological contamination because of the use of livestock manure compost and liquid manure, potential sources of pathogenic bacteria. This study was undertaken to investigate the persistence of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes in soil, liquid manure amended soil, and liquid manure. Loamy soil, liquid manure amended soil, and liquid manure were inoculated with S. enterica, E. coli O157:H7, and L. monocytogenes. Samples were incubated in consistent moisture content at $25^{\circ}C$. Samples had been periodically collected during 120 days depending on the given conditions. S. enterica and E. coli O157:H7 survived over 120 days in loamy soil and over 60 days in liquid manure amended soil, respectively. L. monocytogenes decreased faster than other pathogens in soil. S. enterica, E. coli O157:H7, and L. monocytogenes survived for up to 5 days in liquid manure. S. enterica and E. coli O157:H7 in soil decreased by 2 to $2.5log\;CFU\;g^{-1}$ for 120 days. S. enterica and E. coli O157:H7 in liquid manure amended soil decreased slowly for 21 days. However, S. enterica, E. coli O157:H7, and L. monocytogenes sharply decreased after 21 days. S. enterica, E. coli O157:H7, and L. monocytogenes in soil increased by 0.5 to $1.0log\;CFU\;g^{-1}$ for 7 days. Foodborne pathogens in soil and liquid manure amended soil gradually decreased over time.

• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.92-95
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• 1983

The addition products of glutathione to ${\beta}$ -nitrostyrene derivatives were synthesized. ${\beta}$ -Nitrostyrene (1a), p-methyl-${\beta}$-nitrostyrene (1b), 3,4,5-trimethoxy-${\beta}$-nitrostyrene (1c), o-, m- and p-chloro-${\beta}$-nitrostyrene (1e, 1f, 1g) and o-, m- and p-methoxy-${\beta}$-nitrostyrene (1h, 1i, 1j) undergo addition reactions with glutathione to form S-(2-nitro-1-phenylethyl)-L-glutathione (5a), S-[2-nitro-1-(p-methyl)phenylethyl]-L-glutatione (5b), S-[2-nitro-1-(3', 4', 5'-trimethoxy)phenylethyl]-L-glutathione (5c), S-[2-nitro-1-(o-chloro)phenylethyl]-L-glutathione (5e), S-[2-nitro-1-(m-choro)phenylethyl]-L-glutathione (5f), S-[2-nitro-1-(p-chloro)phenylethyl]-L-glutathione (5g), S-[2-nitro-x-(o-methoxy)-phenylethyl]-L-glutathion e(5h), S-[2-nitro-x-(m-methoxy)phenylethyl]-L-glutathion e (5i), and S-[2-nitro-1-(p-methoxy)phenylethy])-L-glutathione (5j), respectively. The structure of adducts were identified by UV and IR-spectra, molecular weight measurement, and elemental analysis.

• Journal of the Korean Ceramic Society
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• v.40 no.11
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• pp.1113-1119
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• 2003

We used isopropanol which has low boiling point to prepare thin films at low temperature and changed mole concentration of zinc acetate from 0.3 to 1.3 mol/l. The structural, optical and electrical properties of ZnO thin films with Zn content were investigated. ZnO thin films highly oriented along the c-axis were obtained at Zn concentration of 0.7 mol/l. ZnO thin films with Zn concentration of 0.7 mol/l showed a homogeneous surface layer of nano structure. The transmittance of ZnO thin films by UV-vis. measurement was about 87% under the Zn concentration of 0.7 mol/l, but rapidly decreased over the 1.0 mol/l. The optical band gap energy was obtained from 3.07 to 3.22 eV which is very close to the band gap of bulk ZnO (3.2 eV). The electrical resistivity of ZnO thin films was about 150 $\Omega$-cm that shows little difference with Zn concentration. I-V curves of ZnO thin films exhibited typical ohmic contact properties.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1721-1724
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• 2011

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.210-213
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• 2002

The blue phosphor, $BaMgAl_{10}O_{17}$:$Eu^{2+}$, showing a blue emission band at about 450 nm were prepared by solid state reaction of BaC $O_3$, A $l_2$ $O_3$, MgO and E $u_2$ $O_3$ with Al $F_3$ as a flux. The thermal quenching of BaMgAl $O_{17}$:E $u^{2+}$ phosphor significantly reduces the intensity of the blue emission. It is reduced by an amount of 50% after heating at around 800$^{\circ}C$ for 1 hr. The red emission in the 580∼720 nm region of $^{5}$ $D_{0}$\longrightarro $w^{7}$ $F_1$ and $^{5}$ $D_{0}$\longrightarro $w^{7}$ $F_2$ transition of $Eu^{3+}$ is produced from the phosphor heated above 1,100$^{\circ}C$. The EPR spectrum also reveals that some part of E $u^{2+}$ ions are oxidized to trivalent ions above 1,100$^{\circ}C$ at around 90 and 140mT. This oxidation evidence is also detected from XANES absorption spectra for $L_{III}$ shell of Eu ions: an absorption peak is at 6,977eV of E $u^{2+}$ and 6,984eV of $Eu^{3+}$. The combined X-ray and neutron data suggests that the new phase of EuMgA $l_{11}$ $O_{19}$ magnetoplumbite structure may be formed by heat treatment.eat treatment.tment.eat treatment.tment.t.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.858-863
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• 2004

The thermoelectric power, dc conductivity and magnetic properties of the cubic L $a_{2}$ 3/Ti $O_{2.84}$ were investigated. The thermoelectric power was negative below 350 K. The measured thermoelectric power of L $a_{2}$ 3/Ti $O_{2.84}$ increased linearly with temperature, in agreement with model proposed by Emin and Wood, and was represented by A+BT. Temperature dependence indicates that the charge carrier in this material is a small polaron. L $a_{2}$ 3/Ti $O_{2.84}$ exhibited a cross over from variable range hopping to small polaron hopping conduction at a characteristic temperature well below room temperature. The low temperature do conduction mechanism in L $a_{2}$ 3/Ti $O_{2.84}$ was analyzed using Mott's approach. Mott parameter analysis gave values for the density of state at Fermi level [N( $E_{F}$)] = 3.18${\times}$10$^{20}$ c $m^{-3}$ e $V^{-1}$ . The disorder energy ( $W_{d}$) was found to be 0.93 eV, However, it was noted that the value of the disorder energy was much higher than the high temperature activation energy. The exist linear relation between log($\sigma$T)와 1/T in the range of 200 to 300 K, the activation energy for small polaron hopping was 0.15 eV.

• Food Science and Preservation
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• v.5 no.4
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• pp.380-385
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• 1998

The sensitivity of various pathogenic bacteria(Aeromonas hydrophila, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus 196E, Salmonella typhimurium) to the ethanol extract of pine needle was tested. Tryptic soy broth containing 0-2%(w/v) of the ethanol extract of pine needle was inoculated with 10$^4$-10$\^$6/ CFU/ml of pathogenic bacteria and incubated at 35$^{\circ}C$ for 48 hours. Gram positive bacteria(L. monocytogenes and S. aureus 196E) and 1 Gram negative bacteria(A. hydrophila) were more sensitive than E. coli O157:H7 and S. typhimurium in the ethanol extract of Pine needle. Gram negative bacteria(E. coli O157:H7 and S. typhimurium) were not inhibited at 1% and they were slightly inhibited at 2% ethanol extract of pine needle. S. aureus was the highest sensitivity, followed by A. hydrophila, L. monocytogenes E. coli O157:H7 in that order. S. typhimurium was the most resistant to the ethanol extract of pine needle.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.604-609
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• 2019

To control pathogenic E. coli in biofilm, bacteriophages were isolated from environmental samples. Seventeen isolates had depolymerase activities by translucent zones at the rims of plaques. To determine biofilm-forming ability, an abiotic plastic surface of polystyrene was used; E. coli O103 showed the highest biofilm formation at 30℃ after 24 h. Moreover, biofilm by E. coli O103 on the biotic surface of lettuce was observed by a scanning electron microscope. The bacteriophage cocktail of ΦNOECP40 and ΦNOECP44 showing depolymerase activities was prepared to eliminate the E. coli inbiofilm. By organic acids, reduction of E. coli in biofilm was insignificant and almost undetectable. However, the abundance of E. coli in biofilm was reduced by 3 log CFU/mL from 7.3 log CFU/mL after 60 min with the bacteriophage cocktail. Therefore, we suggest that bacteriophages with depolymerase could be utilized to effectively control pathogenic E. coli in biofilm.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.196-199
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• 1996

The amplitude LSF(Line spread function, $C_1e^{{o^2}{x^2}}$ or amplitude impulse) of the Gaussian apodized annular pupil is found to be same to that of the full aperture LSF($C_0e^{{o^2}{x^2}}$). $C_0$ and $C_1$ depending on $\sigma$, ${\omega}_0=\frac{2{\pi}}{\lambda}\;\frac{a_0}{l}$ and ${\omega}_0'=\frac{2{\pi}}{\lambda}\;\frac{a_0'}{l}$ which are the geometric parameter and pupil coordinates of the annular pupil. The important inequality relation among ${\omega}_0,\;{\omega}_0'$, a (fraction of diffraction amplitude) and $\sigma$ is obtained. It is $\frac{{\omega}_0}{\sqrt{2}}<{\sigma}{\le}(\frac{1-a}{2a})^{1/2}\;{\omega}_0$, and in the case of $a=e^{-1},\;a_0'{\le}0.34a_0$. The case of λ=0.013${\mu}{\textrm}{m}$, l=20 cm, $a_0=5cm$ and $a_0=0.34a_0=1.7cm$ give a Gaussian apodized superresolution ${\Delta}=\frac{\sqrt{log2}}{\sigma}=0.008{\mu}m$ annular pupil with the intensity signal equal to $e_{-2}$ times the signal obtainable by using the full aperture system(a=1)

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.491-494
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• 2009

Within the secondary metabolite class of flavonoids, which consist of more than 10,000 known structures, flavones define one of the largest subgroups. The diverse function of flavones in plants as well as their various roles in the interaction with other organisms offers many potential applications including in human nutrition and pharmacology. We used two genes, flavone synthase (PFNS-l) that converts naringenin into apigenin and flavone 7-O-methyltransferase (POMT-7) that converts apigenin into 7-O-methyl apigenin, to synthesize 7-O-methyl apigenenin from naringenin. The PFNS-l gene was subcloned into the E. coli expression vector pGEX and POMT-7 was subcloned into the pRSF vector. Since both constructs contain different replication origins and selection markers, they were cotransformed into E. coli. Using E. coli transformants harboring both PFNS-l and POMT-7, naringenin could be converted into 7-O-methyl apigenin, genkwanin.