• Journal of Pharmaceutical Investigation
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• v.38 no.1
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• pp.15-21
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• 2008

Liposomes as one of the efficient drug carriers have some shortcomings such as their short circulation time, fast clearance from human body by reticuloendothelial system (RES) and limited intracellular uptake to target cell. In this study, polyethylenglycol (PEG)-incorporated cationic liposomes were prepared by ionic complexation of positively charged liposomes with carboxylated polyethyleneglycol (mPEG-COOH). The cationic liposomes had approximately $98.6{\pm}1.0nm$ of mean particle diameter and $42.8{\pm}0.8mV$ of zeta potential value. The PEG-incorporated cationic liposomes had $110.1{\pm}1.2nm$ of mean particle diameter with an increase of about 10 nm compared to the cationic liposomes. Zeta potential value of them was $12.9{\pm}0.6mV$ indicating 30mV decrease of cationic charge compared to the cationic liposomes. The amount of PEG which was incorporated onto the cationic liposomes was assayed by using picrate assay method and the incorporation efficiency was $58.4{\pm}1.1%$. Loading efficiency of model drug, doxorubicin, into cationic liposomes or PEG-incorporated cationic liposomes was about $96.0{\pm}0.7%$. Results of intracellular uptake which were evaluated by flow cytometry analysis of doxorubicin loaded liposomes showed that intracellular uptake of PEG-incorporated cationic liposomes was higher than the cationic liposomes or DSPE-mPEG liposomes. In addition, cytotoxicity of PEG-incorporated cationic liposomes was comparable to cationic liposomes. Consequently, the PEG-incorporated cationic liposomes of which surface was incorporated with PEG by ionic complex may be applicable as anticancer drug carriers that can increase therapeutic efficacy.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.657-672
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• 2008

The purposes of this study are to investigate the hydrogeochemical characteristics of groundwaters around Keumsan municipal landfill, and to evaluate the contaminant dispersion from the landfill and its environmental impact. To achieve these goals, groundwater quality logging, hydrochemical analysis, multivariate statistical analysis, and contaminant transport modeling were performed. The water quality logging indicated a leaking from the landfill at the depth of 4-12m around a leachate sump. Electrical conductivity data indicated that groundwaters within 70-100m from landfill were affected by the landfill leakage. Principal components 1 and 2 obtained from principal components analysis (PCA) reflect the influence of leachate and the characteristics of aquifer media, respectively. The results of principal component analysis also indicated the natural attenuation processes such as cation exchange, sorption, and microbial biodegradation. The modeling results showed that groundwater flow westward along a valley from the landfill and contaminants transport accordingly.

• Journal of Plant Biotechnology
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• v.42 no.1
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• pp.19-24
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• 2015

Glycine betaine (GB) is one of the compatible solutes that accumulate in the chloroplasts of certain halotolerant plants under salt or cold stress. The codA gene for choline oxidase, the enzyme that converts choline into GB, has been cloned from a soil bacterium Arthrobacter globiformis. We generated transgenic sweetpotato plants [Ipomoea batatas (L.) Lam] expressing codA gene in chloroplasts under the control of the SWPA2 promoter (referred to as SC plants) and evaluated SC plants under oxidative and drought stresses. SC plants showed enhanced tolerance to methyl viologen (MV)-mediated oxidative stress and drought stress due to induced expression of codA. At $5{\mu}M$ of MV treatment, all SC plants showed enhanced tolerance to MV-mediated oxidative stress through maintaining low ion leakage and increased GB levels compared to wild type plants. When plants were subjected to drought conditions, SC plants showed enhanced tolerance to drought stress through maintaining high relative water contents and increased codA expression compared to wild type plants. These results suggest that the SC plants generated in this study will be useful for enhanced biomass production on global marginal lands.

• Journal of the Korean Vacuum Society
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• v.21 no.6
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• pp.348-353
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• 2012

We investigated chemical states of a $Sb_2Te_3$ thin film with the polycrystalline phase by using high-resolution x-ray photoelectron spectroscopy with synchrotron radiation. The $Sb_2Te_3$ thin film was formed by sputtering. The rhombohedral phase was confirmed by x-ray diffraction. To remove the surface oxide, we performed $Ne^+$ ion sputtering for 1 hour with the beam energy of 1 kV and post-annealing at $100^{\circ}C$ for 5 min in ultra-high vacuum. We obtained the Te and Sb 4d core-levels spectra with the peaks at the binding energies of 40.4 and 33.0 eV, respectively. The full-width of half maximum of both the Te and Sb $4d_{5/2}$ core-levels is 0.9 eV. The Te and Sb core-levels only show a single chemical state, and we also confirmed the stoichiometry of approximately 2 : 3.

• Journal of Plant Biotechnology
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• v.38 no.2
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• pp.162-168
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• 2011

High salinity is a common stress condition that adversely affects plant growth and crop production. In response to various environmental stresses, plants activate a number of defense genes that function to increase the tolerance. To isolate Arabidopsis genes that are involved in abiotic stress responses, we carried out genetic screening using various mutant lines. Among them, the blh8 ($\b{B}$EL1-$\b{L}$ike $\b{H}$omeodomain $\underline{8}$) mutant specifically shows chlorotic phenotypes to ionic (specifically, $Na^+$ and $K^+$) stresses, but no differences in root growth. In addition, BLH8 is related to plant development and abiotic stress as predicted by a Graphical Gaussian Model (GGM) network program. It implies that BLH8 functions as a putative transcription factor related to abiotic stress responses. Collectively, our results show that gene network analysis is a useful tool for isolating genes involved in stress adaptation in plants.

• Korean Journal of Medicinal Crop Science
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• v.10 no.2
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• pp.100-108
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• 2002

This experiment was carried out to investigate the cultivation condition of soil salinity, manure and to find out the cultivation capability of Salicornia herbacea. The optimal growth condition of soil salinity was between 1% and 4%. The growth of groups for fertilization was significantly better than control group. Salicornia herbacea grew very up from 7 kg/l0a to 9 kg/l0a for N, 12 kg/l0a for P and the K-fertilizer group was better than control group but there was not significantly different among the conditions of K-concentration. The germination was good from $0{\textperthousand}\;to\;5{\textperthousand}$ for salinity, from $20^{\circ}C\;to\;30^{\circ}C$ for temperature. On the experiment cultivation, the production by hill seeding was $5.40{\sim}5.90 kg/m^2$ and was significantly higher than the yield by broadcast sowing which was $4.01{\sim}4.20 kg/m^2$. The production by hill seeding was 2.7 times than natural production and the production by broadcast sowing 1.9 times.

• Analytical Science and Technology
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• v.11 no.3
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• pp.189-193
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• 1998

Binary alloys, $MoRu_3$ and $MoRh_3$, have been prepared using arc melting furnace. Mo and the noble metals Ru and Rh are the constituents of metallic insoluble residues, which were found in the early days of the post-irradiation studies on uranium oxide fuels. Detailed structural informations about these alloys have not been reported on JCPDS files of ICDD (International Centre for Diffraction Data). The results of X-ray diffraction study showed that the alloy was crystallized in hexagonal close-packing, well known as ${\varepsilon}$-phase. The X-ray diffraction patterns of these alloys matched well to that of $WRh_3$ with $P6_3/mmc$ of space group. The lattice parameters, a and c, were calculated using the least squares extrapolation. It was found from X-ray photoelectron spectroscopic measurements that Mo on the surface of the alloy was oxidized to Mo(6+), which could be removed by sputtering with Ar ions for approximately 15 minutes. The changes in binding energy of Mo, Ru, and Rh on the surface of the alloy were not observed. Magnetic susceptibility measurements resulted in the typical Pauli-paramagnetic behavior in the temperature range of 2 to 300 K.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.121-128
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• 2005

A study on the selective separation of $^{99}Tc,\;^{94}Nb,\;^{55}Fe,\;^{90}Sr$ and $^{59}Ni(^{63}Ni)$ from various radioactive wastes discharged from the nuclear power plants in Korea is being performed for use in their quantifications which are indispensible for the evaluation of the radionuclide inventory. Separation behaviour of Ce, Ca, Mg, Al, Cr, Ti, Mn and Cu recovered along with Ni during the separation of Re (as a surrogate of $^{99}Tc$), Nb, Fe and Sr by anion exchange and Sr-Spec extraction chromatography was investigated by cation exchange and Ni-Spec extraction chromatography using synthetic radioactive waste dissolved solutions containing matrix elements such as Re, Nb, Fe, Sr, Ni, B, Na, K, Ce, Co, Ca, Mg, Al, Zn, Cr, Pb, Cd, Mo, Mn, Cu, Zr, Ti and U. To purify the Ni fraction recovered and prepare a radionuclide source available for gas proportional counting, an application of the Ni precipitation procedure with dimethylglyoxime in the medium of ammonium citrate and tartaric acid solutions as a masking agent for co-existing metal ions was described in detail.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.381-390
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• 2005

S City depends on the T River as source water for water supply. Arsenic and boron from the hot-spring waste-water discharged from the hot-spring spa resort and emerging from the fractures of bedrock of the river have been prevalent contaminant of the T River water. This research was conducted to propose the simple and quick surrogate parameter for water quality management easily. And through making hexa-diagram of principal ions in the water samples, existing state of the water and influence of the human activity or geological origin can be figured out. As a results of characteristics of the T River water quality using principal component analysis, the contributory percentages of the 1st, 2nd and 3rd principal components were $40.80\%,\;21.40\%\;and\;11.31\%$, respectively. Therefore it was clarified that the quality of the T River water could be explained by these three principal components. Concentration of the chloride ion, which is one of the characteristics of the hot-spring water, was well correlated to both arsenic and boron concentrations. Hence concentrations of the arsenic and boron in the raw water of the water reatment plant can be predicted by the measurement of concentration of the chloride ion.

• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.165-170
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• 2009

The increase in P availability to rice under flooded soil conditions involves the reductive dissolution of iron phosphate and iron (hydr)oxide phosphate. However, since $NO_3^-$ is a more favourable electron acceptor in anaerobic soils than Fe, high$NO_3^-$ loads function as a redox buffer limiting the reduction of Fe. The effect of adding $NO_3^-$ on Fe reduction and P release in paddy soil was investigated. Pot experiment was conducted where $NO_3^-$ was added to flooded soil and changes of redox potential and $Fe_2^+$, $NO_3^-$ and $PO_4^{3-}$ concentrations in soil solution at 10 cm depth were monitored as a function of time. Redox potential decreased with time to -96 mV, but it was temporarily poised at about 330${\sim}$360 mV when $NO_3^-$ was present. Nitrate addition to soil led to reduced release of $Fe_2^+$ and prevented the solubilization of P. Phosphate in pore water began to rise soon after incubation and reached final concentrations about 0.82 mg P/L in the soil without $NO_3^-$ addition. But, in the soil with $NO_3^-$ addition, $PO_4^{3-}$ in pore water was maintained in the range of 0.2${\sim}$0.3 mg P/L. The duration of inhibition in $Fe_2^+$ release was closely related to the presence of $NO_3^-$, and the timing of $PO_4^{3-}$ release was inversely related to the $NO_3^-$ concentration in soil solution. The results suggest that preferential use of $NO_3^-$ as an electron acceptor in anaerobic soil condition can strongly limit Fe reduction and P solubilization.