• Journal of Life Science
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• v.24 no.9
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• pp.959-966
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• 2014

This study was carried out to develop a functional healthy drink using 60% ethanol of dried Acanthopanax senticosus stem extract (ASE). The preparation, physical activity, anti-oxidant activity, and sensory properties of ASE were investigated. The moisture, crude protein, crude lipid, and ash contents of dried ASE were $6.50{\pm}0.12%$, $5.89{\pm}0.16%$, $1.18{\pm}0.11%$, and $3.03{\pm}0.40%$ respectively. The 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was $87.42{\pm}1.63%$ at 1/10 folds diluted ASE. In total, 40 male ICR mice were divided into five groups including the control (PBS), positive control (Red ginseng 200 mg/kg/day), and ASE-treated groups at doses of 35, 70, and 140 mg/kg/day for five weeks, respectively. ASE was administrated orally one time per day for five weeks before treadmill exercises, and normal and positive controls were fed PBS and red ginseng extract. In the treadmill test, ASE-treated mice (140 mg/kg/day) could run 1.4 times longer than the control mice. Healthy drinks were prepared with the addition of ASE at levels of 0.97% or 0.49% (A, B, and C type). Among the healthy drinks, the B type (ASE, 0.97%) was revealed to have the highest level of taste and overall acceptability through a sensory evaluation. The brix and pH of the ASE health drink (B type) were 14.9 and 4.51, respectively. These results indicated that the dried stem of Acanthopanax senticosus could be used as a functional material in the health drink industry.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.199-212
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• 2014

The physiological responses of three common temperate species, Pinus densiflora, Fraxinus rhynchophylla, Sorbus alnifolia to elevated $CO_2$ was investigated using open top chambers with different $CO_2$ concentrations. Morphological (stomatal size, density and area) and physiological characteristics (maximum rates of photosynthesis, carboxylation and electron transport) were compared among trees grown under ambient, ambient ${\times}1.4$ (~550 ppm) and ambient ${\times}1.8$ (~700 ppm) $CO_2$ concentrations for last four years. Morphological responses were different among species. F. rhynchophyllar increased their stomatal size and S. alnifolia had higher stomatal density under elevated $CO_2$ than ambient. Stomatal area decreased in P. densiflora, whereas it increased in S. alnifolia. However, the maximum photosynthesis rate increased in all species up to 43.5% by S. alnifolia under elevated $CO_2$ and the enhancement increased with time. Even with four years of exposure to elevated $CO_2$, there was no sign of acclimation in the maximum carboxylation rate and the maximum electron transport rates in all species. Especially, S. alnifolia even showed the temporary increase of photosynthetic capacities in spring, when leaf nitrogen concentration was high with new leaf development. There was no significant differences in diameter growth rate in any species due to high variation in their tree sizes, however accumulated diameter and biomass for four years showed significantly increment in all species under elevated $CO_2$. For example, S. alnifolia showed 59% increase in diameter at the ambient ${\times}1.8$ (~700 ppm) compared to ambient.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.219-228
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• 1990

A kanamycin resistance($Km^r$) gene was studied for its transfer in natural freshwater environments by using the natural bacterial isolate(M1) of DK1 and the DKC601 strain, $Km^r$ plasmid of which was genetically engineered from the NI strain. The transfer frequency ofthe $Km^r$ gene and rearrangement of the $Km^r$ plasmid were compared between the gnetically engineered microorganism(GEM) and the NI parental strain by conjugation with the same recipient strain. The transfer frequency of the $Km^r$ gene was about $9.1\times 10^{-12}-1.8\times 10^{-11}$ in both the GEM and NI strains at 5 to $10^{\circ}C$, but the frequency of the NI was about 10 times higher than that of the GEM at 20 to $30^{\circ}C$. The $Km^r$ plasmid in the transconjugants obtained by conjugation of the NI with the MY1 strain as a ricipient showed alot of rearrangement, but the $Km^r$ plasmid transferred from the GEM was stable without alteration of its size. When the MT2 strain was used as a recipient, however, such a rearrangement of the $Km^r$ plamid was observed in the transconjugants obtained from the GEM as well as the NI strain. In those transconjugants obtained from different mating pairs and water environments, the plasmid were appeared to decrease in their number as the period of conjugation time was prolonged, but only the $Km^r$ plasmid transferred from the GEM kept having its size of 52kb. Therefore, the $Km^r$ gene was transferred at the same rate from the GEM and NI strains in natural freshwater environment, but the gene of the GEM strain was more stable than the NIduring conjugation and the $Km^r$ plasmid was rearranged by changing the recipient strain for conjugation in any water environments.

• Journal of the Korean Geographical Society
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• v.28 no.4
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• pp.285-297
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• 1993

For the application of the diffusion equation, slope height and maximum slope angle are calculated from the plotted slope profile. Using denudation rate as a solution for the diffusion equation, an apparent age index can be calculated, which is the total amount of denudation through total time. Plots of slope angle versus slope height and apparent age index versus slope height are useful for determining relative or absolute ages and denudation rates. Mathematical simulation plots of slope angle versus slope height can generate equal denudation-rate lines for a given age. Mathematical simulations of slope angle versus age for a given slope height, for equal denudation-rate at a particular profile site, and for comparing to other sites having controlled ages.

• Tuberculosis and Respiratory Diseases
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• v.56 no.1
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• pp.40-50
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• 2004

Background : Radiation pneumonitis(RP) is the major serious complication of thoracic irradiation treatment. In this study, we attempted to retrospectively evaluate the long-term prognosis of patients who experienced acute RP and to identify factor that might allow prediction of RP. Methods : Of the 114 lung cancer patients who underwent thoracic radiotherapy between December 2000 and December 2002, We performed analysis using a database of 90 patients who were capable of being evaluated. Results : Of the 44 patients(48.9%) who experienced clinical RP in this study, the RP was mild in 33(36.6%) and severe in 11(12.3%). All of severe RP were treated with corticosteroids. The median starting corticosteroids dose was 34 mg(30~40) and median treatment duration was 68 days(8~97). The median survival time of the 11 patients who experienced severe RP was significantly poorer than the mild RP group. (p=0.046) The higher total radiation dose(${\geq}60Gy$) was significantly associated with developing in RP.(p=0.001) The incidence of RP did not correlate with any of the ECOG performance, pulmonary function test, age, cell type, history of smoking, radiotherapy combined with chemotherapy, once-daily radiotherapy dose fraction. Also, serum albumin level, uric acid level at onset of RP did not influence the risk of severe RP in our study. Conclusion : Only the higher total radiation dose(${\geq}60Gy$) was a significant risk factor predictive of RP. Also severe RP was an adverse prognostic factor.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.650-658
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• 2006

The recycling of TDA from solid waste of TDI plant(TDI-R) by near-critical hydrolysis reaction had been studied by means of a statistical design of experiment. The main and interaction effects of process variables had been defined from the experiments in a batch reactor and the correlation equation with process variables for TDA yield had been obtained from the experiments in a continuous pilot plant. It was confirmed that the effects of reaction temperature, catalyst type and concentration, and the weight ratio of water to TDI-R(WR) on TDA yield were significant. TDA yield decreased with increases in reaction temperature and catalyst concentration, and increased with an increase in WR. As a catalyst, NaOH was more effective than $Na_2CO_3$ for TDA yield. The interaction effects between catalyst concentration and temperature, WR and temperature, catalyst type and reaction time on TDA yield had been defined as significant. Although the effect of catalyst concentration on TDA yield at $300^{\circ}C$ as subcritical water was insignificant, the TDA yield decreased with increasing catalyst concentration at $400^{\circ}C$ as supercritical water. On the other hand, the yield increased with an increase in WR at $300^{\circ}C$ but showed negligible effect with WR at $400^{\circ}C$. The optimization of process variables for TDA yield has been explored with a pilot plant for scale-up. The catalyst concentration and WR were selected as process variables with respect to economic feasibility and efficiency. The effects of process variables on TDA yield had been explored by means of central composite design. The TDA yield increased with an increase in catalyst concentration. It showed maximum value at below 2.5 of WR and then decreased with an increase in WR. However, the ratio at which the TDA yield showed a maximum value increased with increasing catalyst concentration. The correlation equation of a quadratic model with catalyst concentration and WR had been obtained by the regression analysis of experimental results in a pilot plant.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.588-596
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• 2006

The surface of polystyrene membrane treated by Ar, $O_2$ plasma, and the effects were observed before and after the treatment and permeability of $CO_2$, $N_2$ and selectivity of $CO_2$ relative to $N_2$ was measured using continuous flow gas permeation analyzer (GPA). The mole ratio of O over C in the surface was increased from 0 to 0.179 with Ar plasma treatment and route mean square of surface was increased from $15.86{\AA}$ to $71.64{\AA}$. Therefore the contact angle was decreased from $89.16^{\circ}$ to $18.1^{\circ}$. Thus Plasma treatments made surface of membrane tend to be highly hydrophilic. The optimum condition for the $CO_2$ permeability and ideal selectivity of the plasma treated membrane was as follows: the measurement of Ar (60 W, 2 min, $70^{\circ}C$) plasma treatment was $1.14{\times}10^{-12}[m^3(STP){\cdot}m/m^2{\cdot}sec{\cdot}atm]$ and 4.22. In the case of $O_2$ plasma treatment, the contact angle was decreased at $13.56^{\circ}$ with increase of O/C ratio ($0.189{\AA}$) and route mean square of surface ($57.10{\AA}$). The optimum condition for the $CO_2$ permeability and ideal selectivity of the plasma treated membrane was as follows: the measurement of $O_2$ (90 W, 2 min, $70^{\circ}C$) plasma treatment was $7.1{\times}10^{-12}[m^3(STP){\cdot}m/m^2{\cdot}sec{\cdot}atm]$ and 11.5. After plasma treatment, the changes of membrane surface were all subtly linked with both cross-linking and etching effects. Finally, it was confirmed that the gas permeation capacity and selectivity of the modified membrane with plasma could be improved by an appropriate control of the plasma conditions such as treatment time, the power input and sort of plasma gas.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.115-124
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• 2009

New strain needs to maintain desirable characteristics for long term when it was bred, but in lapse of time it degenerates into a bad condition. Therefore the influence of temperature on the viability and survival rates of Lentinula edodes strains were examined after cryopreservation. Also, liquid nitrogen preservation for L. edodes has been proved to be one of the most reliable method. However, a mechanical damage of strain is inevitable during cryopreservation of the fungus because the fungus is very sensitive to stress of cooling rate in the freezing process. So we tried to find out state change of L. edodes with a programmable freezer. L. edodes strains were preserved at $-20^{\circ}C$, $-80^{\circ}C$ and $-196^{\circ}C$ for 50 days. At $-20^{\circ}C$, its mycelial growth became extinct. When thawed, the growth of mycelia which were preserved at $-80^{\circ}C$ was fastest. Attempts were made to investigate viability of L. edodes strains after freezing at $-80^{\circ}C$ and $-196^{\circ}C$, respectively. As the result, more than 90% showed high survival rate of strains tested at $-80^{\circ}C$ and $-196^{\circ}C$. Mycelial growth between apical and basal parts of colony after freezing preservation for 50 days was compared. At apical and basal parts, the survival rates showed 100% at $-80^{\circ}C$, but 98% and 94% at $-196^{\circ}C$, respectively. We confirmed that the ice crystal formation temperatures of L. edodes strains were $-6.0^{\circ}C$ for Sanlim 1, $-5.5^{\circ}C$ for the Sanlim 2, $-4.0^{\circ}C$ for the Sanlim 3 and $-15.5^{\circ}C$ for the Sanzo 302. These results indicated that L. edodes strains showed completely different responses to the ice crystal formation. We knew the fact that even the same species, especially L. edodes, they displayed completely different responses to the same freezing condition. Also, this has nothing to do with the connection between temperature type and freezing point. And a protocol was tried to minimize state change of L. edodes strains using programmable freezer when they are frozen, but it was not effective on them.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.458-463
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• 2009

To establish and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and accurate quantitation of diarrhetic shellfish poisoning (DSP) toxins, we compared the results from different mobile phases and columns used for their analysis and collision energies for MS/MS experiments. Clear peaks of okadaic acid (OA) and dinophysistoxin-1 (DTX1) were obtained by using a mobile phase comprising aqueous acetonitrile containing 2 mM ammonium formate and 50 mM formic acid. The collision energies were optimized to facilitate the most sensitive detection for each toxin, namely, OA, DTX1, pectenotoxin-2 (PTX2), or yessotoxin (YTX). Further, the maximum ion response was obtained at a collision energy of 48 V for OA and DTX1. We compared the analytical performance of $C_8$ and $C_{18}$ columns. A wide range of toxins namely, OA, DTX1, PTX2, and YTX, except DTX3, were detected by both the columns. Although DTX3 was only detected by the $C_8$ column, we found that the $C_{18}$ column was also suitable for the quantitation of OA and DTX1 the toxins responsible for inducing diarrhea. The limit of detection of OA and DTX1 by the established LC-MS/MS conditions was 1 ng/g, and the limit of quantitation of the toxins under the same conditions was 3 ng/g. The process efficiencies were 91-118% for oysters (Crassostrea gigas) and 96-117% for mussels (Mytilus galloprovincialis) further, we observed no significant effect of matrix during the ionization process in LC-MS/MS. The comparison between mouse bioassay (MBA) and LC-MS/MS yielded varying results because low concentrations of OA and DTX1 were detected by LC-MS/MS in some shellfish samples, which provided positive results on MBA for DSP. The analysis time required by MBA for DSP analysis can be reduced by LC-MS/MS.