• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.3.1-3.6
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• 2009

Introduction: GTPases known as translation factor play a vital role as ribosomal subunit assembly chaperone. The bacterial Obg proteins ($Spo{\underline{0B}}$-associated ${\underline{G}}TP$-binding protein) belong to the subfamily of P-loop GTPase proteins and now it is considered as one of the new target for antibacterial drug. The majority of bacterial Obgs have been commonly found to be associated with ribosome, implying that these proteins may play a fundamental role in ribosome assembly or maturation. In addition, one of the experimental evidences suggested that Bacillus subtilis Obg (BsObg) protein binds to the L13 ribosomal protein (BsL13) which is known to be one of the early assembly proteins of the 50S ribosomal subunit in Escherichia coli. In order to investigate binding mode between the BsObg and the BsL13, protein-protein docking simulation was carried out after generating 3D structure of the BsL13 structure using homology modeling method. Materials and Methods: Homology model structure of BsL13 was generated using the EcL13 crystal structure as a template. Protein-protein docking of BsObg protein with ribosomal protein BsL13 was performed by DOT, a macro-molecular docking software, in order to predict a reasonable binding mode. The solvated energy minimization calculation of the docked conformation was carried out to refine the structure. Results and Discussion: The possible binding conformation of BsL13 along with activated Obg fold in BsObg was predicted by computational docking study. The final structure is obtained from the solvated energy minimization. From the analysis, three important H-bond interactions between the Obg fold and the L13 were detected: Obg:Tyr27-L13:Glu32, Obg:Asn76-L13:Glu139, and Obg:Ala136-L13:Glu142. The interaction between the BsObg and BsL13 structures were also analyzed by electrostatic potential calculations to examine the interface surfaces. From the results, the key residues for hydrogen bonding and hydrophobic interaction between the two proteins were predicted. Conclusion and Prospects: In this study, we have focused on the binding mode of the BsObg protein with the ribosomal BsL13 protein. The interaction between the activated Obg and target protein was investigated with protein-protein docking calculations. The binding pattern can be further used as a base for structure-based drug design to find a novel antibacterial drug.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.48-52
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• 2013

Purpose: The Molybdenum which is the raw material of $^{99}Mo-^{99m}Tc$ generator is produced from the nuclear reactor. However, output has dwindled as the two nuclear reactors supplying the bulk of radioactive material-one in Chalk River, Ontario and the other in Petten, the Netherlands-have been closed for repairs or maintenance. This resulted in the enhancement of its price. So $^{99}Mo-^{99m}Tc$ generator using$(n,{\gamma})^{99}Mo$ is developed by Korea Atomic Energy Research Institute (KAERI). Medicinal availability of this generator is evaluated in this study. Materials and Methods: The radioactivity of $^{99m}Tc$ eluted in generator 1, 2 and 3 unit developed by KAERI was measured. The quality control test of generator such as appearance test, pH test, LAL test, sterility test, chemical impurity (Al) test and radiochemical purity test were performed. Planar and SPECT/CT image sof SD rat (6 weeks, Female) at 2 hr after injection of $^{99m}Tc-HDP$ (hydroxymethylenediphosphonate) (TechneScan HDP, Malinckrodt Medical, Dutch) and $^{99m}Tc-DPD$ (diphosphono-1, 2-propanedicarboxylicacid) (TECEOS, CIS bio international, France) which were labeled with $^{99m}Tc$ eluted in KAERI and commercial generator (40.5 GBq, Malinckrodt Medical, Dutch) using SPECT/CT camera (Symbia, Siemense, Germany) were obtained respectively. Results: The mean radioactivity of $^{99m}Tc$ elution generator 1unit was 4.18 GBq (113 mCi), generator 2 unit was 4.73 GBq (128 mCi) and generator 3 unit was 3.33 GBq (90 mCi). All quality control tests were within normal limit except pyrogentest. Pyrogen test was positive. Planar and SPECT/CT images of rat injected $^{99m}Tc-HDP$ which was labeled with $^{99m}Tc$ eluted in commercial generator show increased uptake in bone, stomach and bowl. Planar images show increased uptake in liver and bone in case of $^{99m}Tc-DPD$. However, images of rat injected $^{99m}Tc-HDP$ and $^{99m}Tc-DPD$ which were labelled $^{99m}Tc$ eluted in KAERI generator show increased uptake in bone, liver and spleen. Conclusion: If shortcoming is removed such as pyrogen and liver appearance, domestic role as an alternative generator is thought to be able to fill and to secure the national medical service by supplying $^{99m}Tc$ when the supply of $^{99m}Tc$ be comes short.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.392-399
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• 2006

In order to develop a new persimmon pickle with a low salt concentration, changes in physicochemical characteristics during soaking of persimmon pickles treated with different organic acids and sugars were investigated at $15^{\circ}C$ for 70 days. The pH of persimmon pickles decreased from pH 6.64 at initial stage to pH 3.99 (control group), pH 2.76-3.33 (citric acid treatment, CT), and pH 3.08-3.34 (acetic acid treatment, AT) after 70-days of soaking. Titratable acidity of AT was higher (0.86-1.18%) than that of CT (0.61-0.78%). After 70-days of soaking, salinity of persimmon pickles treated with stevia leaf powder, sodium saccharin, sucrose, and isomalto-oligosaccharide were 4.94-4.96, 4.00-5.15, 2.99-3.31, and 3.03-3.30%, respectively, and 1.54-3.70% lower than that of the control group (6.69%). The hardness of persimmon pickles in all cases was increased up to 20-40-days of soaking and then decreased. L (lightness), a (redness), and b (yellowness) value of persimmon pickles treated with citric acid were higher than those of AT and the control group. Sensory evaluation of persimmon pickles after 70-days of soaking revealed that CT had the highest scores for color, texture, and overall acceptability. These results indicate that the salt concentration of persimmon pickles could be lowered by the addition of citric acid and various sugars during soaking.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.438-443
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• 2006

Antibacterial effects of six volatile essential oils against Vibrio sp. were evaluated. Volatile components of essential oil were analyzed by gas chromatography and gas chromatography mass spectrometry. Ginger oil treatment inhibited growth of V. parahaemolyticus by 22.5-85.7%. Main volatile compounds of ginger oil were ${\beta}-bisabolene$ (35.19%, peak area) and ${\beta}-sesquiphellandrene$ (12.22%). V. parahaemolyticus was completely inhibited at 1,000 ppm by treatment with mustard oil. Tolerances of V. vulnificus 01 and 02 were twice higher than that of V. parahaemolyticus. Main volatile compound of mustard oil was allyl isothiocyanate (92.55%). Garlic oil treatment of 1,000 ppm inhibited growths of V. parahaemolyticus, V. vulnificus 01, and V. vulnificus 02 by 22.8, 14.6, and 32.9%, respectively. Main volatile compounds of garlic oil were dimethyl sulfide (49.39%) and methyl 2-propenyl disulfide (10.09%). Growth of V. vulnificus 02 was inhibited by 60.6-80.3% via treatment with bud, leaf, and whole oil of clove. Antibacterial activity of whole clove oil on V. vulnificus 02 was stronger than those of ginger, mustard, and garlic oil. Main volatile compounds were eugenol (83.33%) and ${\beta}-caryophyllene$ (7.47%) in clove bud, eugenol (87.46%) and ${\beta}-caryophyllene$ (10.03%) in clove leaf, and eugenol (86.04%) and ${\beta}-caryophyllene$ (9.71%) in whole clove. These results revealed essential oils from spices could be used as potential agents to inhibit Vibrio sp.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.642-647
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• 2006

Yeast selection and the sterilization methods of strawberry juice were optimized for making strawberry wine. In addition, changes in the physicochemical characteristics of the wine during its fermentation were estimated. Maehyang and Yukbo cultivars of strawberry were tested for wine making; they contained 9.8 and 9.3% soluble solids and 0.59 and 0.58% titratable acidities, respectively. Among six yeasts tested, the Wg-15 and Sc-51 strains were selected based on the alcohol yield in the strawberry wine. Alcohol and soluble solid contents following heat treatment ($85^{\circ}C$, 10 min) or $K_2S_2O_5$ (200 ppm) treatment for sterilization were 7.10-7.20% and 5.60-5.80%, respectively, and no differences were observed between the Wg-15 and the Sc-51 strains. However, the flavor of wine produced following heat treatment was slightly better than that following $K_2S_2O_5$ treatment. The greatest amounts of alcohol were produced after 2 days of fermentation at $26^{\circ}C$. The alcohol content in wines produced with 12, 14, and 16% sugar content in the initial stages were 5.1, 6.0-6.2, and 7.5-7.7%, and the soluble solid contents were 3.9-4.3, 4.1-4.3, and 5.0-5.3%, respectively; no significant differences were observed between the Wg-15 and the Sc-51 yeast strains. For making strawberry wine, we proposed that the sugar content of Maehyang or Yukbo cultivars be adjusted to 16% soluble solids in the initial stages with heat treated at $85^{\circ}C$ for 10 min and fermentation with the Wg-15 or Sc-51 yeast strains at $26^{\circ}C$ for 8 days.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.469-474
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• 2006

This study was carried out to investigate the changes of physicochemical characteristics of Schizandra chinensis during postharvest ripening for 8 days at various temperatures. The juice yield of S. chinensis, which was 55.7% before postharvest ripening, was unchanged $(55.3{\pm}0.6-56.3{\pm}0.6%)$ at $4^{\circ}C$ storage, but was decreased at the level of 6 and 7% at $25^{\circ}C$ and room temperature (RT), respectively. During storage at $25^{\circ}C$ and RT, the titratable acidities of S. chinensis were the highest at $7.49{\pm}0.03$ and $7.20{\pm}0.03%$ after 6 days of postharvest ripening, respectively. During storage at $25^{\circ}C$ and RT, the soluble solid content of S. chinensis was increased from $8.2{\pm}0.1%$ at initial stage to a peak of $12.2{\pm}0.15%$ at 6-day storage, after which it decreased. L values (lightness) of S. chinensis were increased in all treatments during storage, and a values (redness) of $25^{\circ}C$ and RT treatments were increased from 5.04 initially to 6.77 and 7.65 at 8-day storage, respectively. The major free sugars of S. chinensis were fructose (0.55%), glucose (0.56%), and sucrose (0.50%). During storage at $25^{\circ}C$ and RT, the fructose and glucose contents were continually increased with increasing storage period, while the sucrose contents decreased after 6-day storage. Major non-volatile organic acids of S. chinensis were succinic (1.21%), citric (0.17%), and malic (0.07%) acids. Changes in the organic acids contents of S. chinensis at various temperatures showed a similar tendency to that of the free sugars. We estimated that the best conditions for the postharvest ripening of S. chinensis were 8 days at $4^{\circ}C$ storage, and 6 days at $25^{\circ}C$ and RT.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.122-126
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• 2010

Purpose: F-18-FPCIT that shows strong familiarity with DAT located at a neural terminal site offers diagnostic information about DAT density state in the region of the striatum especially Parkinson's disease. In this study, we altered the iteration and subset and measured SUV${\pm}$SD and Contrasts from phantom images which set up to specific iteration and subset. So, we are going to suggest the appropriate range of the iteration and subset. Materials and Methods: This study has been performed with 10 normal volunteers who don't have any history of Parkinson's disease or cerebral disease and Flangeless Esser PET Phantom from Data Spectrum Corporation. $5.3{\pm}0.2$ mCi of F-18-FPCIT was injected to the normal group and PET Phantom was assembled by ACR PET Phantom Instructions and it's actual ratio between hot spheres and background was 2.35 to 1. Brain and Phantom images were acquired after 3 hours from the time of the injection and images were acquired for ten minutes. Basically, SIEMENS Bio graph 40 True-point was used and True-X method was applied for image reconstruction method. The iteration and Subset were set to 2 iterations, 8 subsets, 3 iterations, 16 subsets, 6 iterations, 16 subsets, 8 iterations, 16 subsets and 8 iterations, 21 subsets respectively. To measure SUVs on the brain images, ROIs were drawn on the right Putamen. Also, Coefficient of variance (CV) was calculated to indicate the uniformity at each iteration and subset combinations. On the phantom study, we measured the actual ratio between hot spheres and back ground at each combinations. Same size's ROIs were drawn on the same slide and location. Results: Mean SUVs were 10.60, 12.83, 13.87, 13.98 and 13.5 at each combination. The range of fluctuation by sets were 22.36%, 10.34%, 1.1%, and 4.8% respectively. The range of fluctuation of mean SUV was lowest between 6 iterations 16 subsets and 8 iterations 16 subsets. CV showed 9.07%, 11.46%, 13.56%, 14.91% and 19.47% respectively. This means that the numerical value of the iteration and subset gets higher the image's uniformity gets worse. The range of fluctuation of CV by sets were 2.39, 2.1, 1.35, and 4.56. The range of fluctuation of uniformity was lowest between 6 iterations, 16 subsets and 8 iterations, 16 subsets. In the contrast test, it showed 1.92:1, 2.12:1, 2.10:1, 2.13:1 and 2.11:1 at each iteration and subset combinations. A Setting of 8 iterations and 16 subsets reappeared most close ratio between hot spheres and background. Conclusion: Findings on this study, SUVs and uniformity might be calculated differently caused by variable reconstruction parameters like filter or FWHM. Mean SUV and uniformity showed the lowest range of fluctuation at 6 iterations 16 subsets and 8 iterations 16 subsets. Also, 8 iterations 16 subsets showed the nearest hot sphere to background ratio compared with others. But it can not be concluded that only 6 iterations 16 subsets and 8 iterations 16 subsets can make right images for the clinical diagnosis. There might be more factors that can make better images. For more exact clinical diagnosis through the quantitative analysis of DAT density in the region of striatum we need to secure healthy people's quantitative values.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.85-97
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• 2012

To investigate the usefulness of freshwater alga Water-net (Hydrodictyon reticulatum, HR) as resources for production of fermentable sugars, the easiness of enzymatic saccharification was evaluated at first. When 6 plant materials (HR, Spirulina, Chlorella, Scenedesmus, Cladophora, Corn stover) were enzymatically hydrolyzed with 2% solid loading at the same condition, HR showed the highest ratio of saccharification based on glucose production. No milled HR was also completely saccharified at the amounts of optimal enzyme mixture. Glucose yield was not changed though the citrate buffer strength for saccharification was decreased from 0.1 M to 0.1 mM. Only about 10% yield reduction was observed compared to that of $120^{\circ}C$ treatment when HR was enzymatically hydrolyzed at room temperature. The saccharification was normally occurred at $37^{\circ}C$ and pH 6.5 which is general growth condition of fermentable microrganisms, suggesting that HR have a biomass characteristics applicable for the simultaneous saccharification and fermentation. The saccharification was occurred by more than 70~80% of one of the best condition although the supplied enzyme amounts was reduced to 1/10 volume. And the glucose yield by enzymatic hydrolysis was not decreased by 10% HR solid loading and began to decrease at more than 15% solid contents. Above these results show that HR is an interesting algal biomass which is relatively easy to be saccharified by hydrolyzing enzymes. In addition, HR is a flilamentous alga and very easy to be collected. Therefore, HR seems to be an useful and valuable resources in the economical production of fermentable sugars for manufacture of bio-chemical products.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.325-331
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• 2014

The purpose of this study was to establish the proper sowing time and planting density of cowpeas for labor-saving cultivation. Experiments were carried out in Naju, Jeonnam Province (Latitude $35^{\circ}$ 04' N, Longitude $126^{\circ}$ 54' E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed five times between June 25 and August 5 at approximately 10-day intervals in order to establish proper sowing time, and sowed at 5,000, 10,000, 15,000, and 20,000 plants per 10a to establish proper planting density. The days from sowing to first flowering was shortest (32 days) in plants sowed on July 25 and became longer for plants sowed on or around July 25. The days from sowing to first flowering was longest (41 days) in plants sowed on June 25. The days from first flowering to first maturing was shortest (8 days) in plants sowed on June 25 and, became considerably longer at later sowing dates. The days from first maturing to first harvesting ranged from 8 to 10 days, with little difference among the sowing periods. Plants sowed on August 5 harvested at the same time, and plants sowed between June 25 and July 25 were harvested either three or two times. The yield was highest in plants sowed on July 25: 209 kg/10a was harvested for Jeonnam1 and 221 kg/10a for Jeonnam2. Furthermore, harvested at the same time enabled when the harvesting was delayed for around 15 days because the share of the seeds first harvested was highest (91%). The proper planting density was estimated to be 15,000 plants/10a, showing the highest yields of 199 kg/10a for Jeonnam1 and 224 kg/10a for Jeonnam2.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.494-501
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• 2010

The purpose of this study was to examine the presence of Bacillus cereus, aerobic bacteria and coliforms in the raw material of infant formulas and investigate the manufacturing process in terms of microbial safety. Among ten kinds of raw infant formula material samples (n=20), Bacillus cereus appeared in two (n=4). Aerobic bacteria were not detected in raw infant formula material or maximum 4.15 log CFU/g. Eleven species of aerobic bacteria were isolated and 76% of them were Sphingomonas paucimobilis, Pseudomonas fluorescens, Rhizobium radiobactor, or Stenotrophomonas maltophilia. A Pearson's correlation analysis revealed that the most influential factors for detecting Bacillus cereus were aerobic bacteria and coliforms. In other words, when the measured values of aerobic bacteria and coliforms were higher, the possibility that Bacillus cereus would appear increased. In a regression model to predict Bacillus cereus, the rate of appearance was correlated with aerobic bacteria and coliforms, and its contribution rate for effectiveness was 86%. Improving microbial quality control by pasteurization, spray dry, popping and extrusion resulted in a decrease in the numbers of Bacillus cereus, aerobic bacteria and coliforms in the raw materials. The results suggest that a hazard analysis and critical control point system might be effective for reducing microbiological contamination.