• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제19권7호
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• pp.778-784
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• 2008

In this paper, a chip antenna using multi-layer configuration for multi-band operation, such as GSM, DCS, pcs, WCDMA, and Mobile WiMAX for 2.3 GHz is proposed. This proposed antenna is a PIFA structure with multi-layer configuration fabricated on R04003 substrate(${\varepsilon}_r=3.4$) and its size is $22{\times}5.5{\times}4.0\;mm^3$. Multi-layer structure can effectively reduce the size of an antenna from a reuse of air-space and can achieve broad bandwidth due to decrement of parallel capacitances from the insertion air-gap to the middle layer. The proposed antenna has a broadband operation by the high order resonance modes and the resonance at the top layer. The measured bandwidths with over 45 % radiation efficiency are 80 MHz($880{\sim}960\;MHz$) at the lower band and 690 MHz($1,710{\sim}2,400\;MHz$) at the higher band.

• Journal of Life Science
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• 제18권1호
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• pp.136-142
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• 2008

A recombinant Pichia pastoris carrying double expression cassette of Rhodotorula glutinis epoxide hydrolase(RgEH) gene was developed and used for preparing enantiopure (S)-styrene oxide from racemic mixture of styrene oxide. BglII restriction site of original RgEH gene (pPICZ B/RgEH #2) of previous report was mutated using PCR technique for the construction of double expression cassette containing promoter ($P_{AOX1}$), EH gene and transcription terminator ($TT_{AOX1}$) in pPICZ C vector. Double expression cassette with RgEH was inserted into the chromosomal DNA of P. pastoris. $V_{max}$ ($2.2{\mu}mol\;min^{-1}mg\;dcw^{-1}$) on (R)-styrene oxide of P. pastoris with double expression cassette was about 6-fold higher than that ($0.4{\mu}mol\;min^{-1}mg\;dcw^{-1}$) of P. pastoris with single expression cassette. For the determination of the optimal condition, the effects of detergent and temperature on the enantioselective hydrolytic activity and yield of the enantiomer were investigated. When the reaction was performed at $10^{\circ}C$ for 10 min in the presence of 0.5% Tween 20, enantiopure (S)-styrene oxide with 99.9% ee was obtained as the yield 43.4 % from 20 mM racemic sustrate.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1951-1964
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• 2016

1,4-Dioxane-degrading bacterial consortia were enriched from forest soil (FS) and activated sludge (AS) using a defined medium containing 1,4-dioxane as the sole carbon source. These two enrichments cultures appeared to have inducible tetrahydrofuran/dioxane and propane degradation enzymes. According to qPCR results on the 16S rRNA and soluble di-iron monooxygenase genes, the relative abundances of 1,4-dioxane-degrading bacteria to total bacteria in FS and AS were 29.4% and 57.8%, respectively. For FS, the cell growth yields (Y), maximum specific degradation rate ($V_{max}$), and half-saturation concentration ($K_m$) were 0.58 mg-protein/mg-dioxane, $0.037mg-dioxane/mg-protein{\cdot}h$, and 93.9 mg/l, respectively. For AS, Y, $V_{max}$, and $K_m$ were 0.34 mg-protein/mg-dioxane, $0.078mg-dioxane/mg-protein{\cdot}h$, and 181.3 mg/l, respectively. These kinetics data of FS and AS were similar to previously reported values. Based on bacterial community analysis on 16S rRNA gene sequences of the two enrichment cultures, the FS consortium was identified to contain 38.3% of Mycobacterium and 10.6% of Afipia, similar to previously reported literature. Meanwhile, 49.5% of the AS consortium belonged to the candidate division TM7, which has never been reported to be involved in 1,4-dioxane biodegradation. However, recent studies suggested that TM7 bacteria were associated with degradation of non-biodegradable and hazardous materials. Therefore, our results showed that previously unknown 1,4-dioxane-degrading bacteria might play an important role in enriched AS. Although the metabolic capability and ecophysiological significance of the predominant TM7 bacteria in AS enrichment culture remain unclear, our data reveal hidden characteristics of the TM7 phylum and provide a perspective for studying this previously uncultured phylotype.

• Korean Journal of Radiology
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• 제21권5호
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• pp.588-597
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• 2020

Objective: To investigate the value of combined chemical exchange saturation transfer (CEST) and conventional magnetization transfer imaging (MT) in detecting metabolic and structural changes of renal fibrosis in rats with unilateral ureteral obstruction (UUO) at 3T MRI. Materials and Methods: Thirty-five Sprague-Dawley rats underwent UUO surgery (n = 25) or sham surgery (n = 10). The obstructed and contralateral kidneys were evaluated on days 1, 3, 5, and 7 after surgery. After CEST and MT examinations, ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography was performed to quantify glucose metabolism. Fibrosis was measured by histology and western blots. Correlations were compared between asymmetrical magnetization transfer ratio at 1.2 ppm (MTR_asym(1.2ppm)) derived from CEST and maximum standard uptake value (SUV_max) and between magnetization transfer ratio (MTR) derived from MT and alpha-smooth muscle actin (α-SMA). Results: On days 3 and 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of contralateral kidneys (p < 0.05). On day 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of sham-operated kidneys (p < 0.05). The MTR_asym(1.2ppm) of UUO renal medulla was fairly negatively correlated with SUV_max (r = -0.350, p = 0.021), whereas MTR of UUO renal medulla was strongly negatively correlated with α-SMA (r = -0.744, p < 0.001). Conclusion: CEST and MT could provide metabolic and structural information for comprehensive assessment of renal fibrosis in UUO rats in 3T MRI and may aid in clinical monitoring of renal fibrosis in patients with chronic kidney disease.

• Journal of radiological science and technology
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• 제30권2호
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• pp.139-145
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• 2007

Dose evaluation for small field such as stereotactic radiosurgery was performed using $Gafchromic^{(R)}$ EBT film. Every film which irradiated 6MV photon beam was scanned and obtained the optical density(OD) by flat bed scanner after 24 hours of irradiation. This study compared dose from diode in water and Gafchromic $EBT^{(R)}$ film in acrylic phantom to verify the reliability of the film, and to evaluate the SRS in clinical dose distributions from calculation and measurement in the region of virtual target in humanoid and cylindrical phantoms were compared. The Gafchromic $EBT^{(R)}$ film was found to be linear up to 9Gy. The $D_{max}$ for 6 MV was measured at 1.5 cm from the surface by both of diode and the film. As the depth is deeper, the error was measured within $2{\sim}3%$ at $10{\sim}20\;cm$ depth. Comparing between distribution from calculation and measurement, we found that there is 5% error at 90% isodose line. We found that given dose could be measured accurately by using the phantoms. It was feasible to use the Gafchromic $EBT^{(R)}$ film in quality assurance of SRS.

• Translational and Clinical Pharmacology
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• 제26권4호
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• pp.160-165
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• 2018

Indobufen ($Ibustrin^{(R)}$), a reversible inhibitor of platelet aggregation, exists in two enantiomeric forms in 1:1 ratio. Here, we characterized the anti-platelet effect of S- and R-indobufen using response surface modeling using $NONMEM^{(R)}$ and predicted the therapeutic doses exerting the maximal efficacy of each enantioselective S- and R-indobufen formulation. S- and R-indobufen were added individually or together to 24 plasma samples from drug-naïve healthy subjects, generating 892 samples containing randomly selected concentrations of the drugs of 0-128 mg/L. Collagen-induced platelet aggregation in platelet-rich plasma was determined using a Chrono-log Lumi-Aggregometer. Inhibitory sigmoid $I_{max}$ model adequately described the anti-platelet effect. The S-form was more potent, whereas the R-form showed less inter-individual variation. No significant interaction was observed between the two enantiomers. The anti-platelet effect of multiple treatments with 200 mg indobufen twice daily doses was predicted in the simulation study, and the effect of S- or R-indobufen alone at various doses was predicted to define optimal dosing regimen for each enantiomer. Simulation study predicted that 200 mg twice daily administration of S-indobufen alone will produce more treatment effect than S-and R-mixture formulation. S-indobufen produced treatment effect at lower concentration than R-indobufen. However, inter-individual variation of the pharmacodynamic response was smaller in R-indobufen. The present study suggests the optimal doses of R-and S-enantioselective indobufen formulations in terms of treatment efficacy for patients with thromboembolic problems. The proposed methodology in this study can be applied to the develop novel enantio-selective drugs more efficiently.

• Food Science and Biotechnology
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• 제17권3호
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• pp.679-682
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• 2008

A lactic acid bacterium producing an antimicrobial substance against Escherichia coli O157:H7 was isolated from raw milk and identified as Lactobacillus amylovorus ME-1. In addition to E. coli O157 :H7, the antimicrobial substance also inhibited the growth of Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyrogenes, and Yersinia enterocolitica. The antimicrobial substance was stable at pH 2-12 and $121^{\circ}C$ for 15 min and insensitive to proteinase K, protease, amylase, and catalase. Purification of the antimicrobial substance was conducted through methanol and acetonitrile/ethylacetate extraction, ultrafiltration with a 500 Da cutoff, thin layer chromatography (TLC) with silicagel 60, and high performance liquid chromatography (HPLC) with a $C_{18}$ reverse phase column. The ${\lambda}_{max}$ of the purified antimicrobial substance was determined as 192 nm by ultra violet (UV) scanning, while the molecular weight was estimated as 453 Da based on the mass spectrum. Accordingly, the current results suggest that the antimicrobial substance from the L. amylovorus ME-1 was not a bacteriocin, but rather a new non-proteinaceous substance distinct from acidophilin, acidolin, diacetyl, and reuterin.

• Journal of Marine Bioscience and Biotechnology
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• 제7권1호
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• pp.11-18
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• 2015

An extracellular alkaline ${\alpha}$-D-mannosidase produced by a strain named as MA-01 was produced and its preliminary enzyme activity was characterized. Upon determining the 16S rDNA sequence and its homology search, the strain was identified to be one of species of the Bacillus safensis. Localization of enzyme was elucidated that ${\alpha}$-D-mannosidase can be found in culture medium as an extracellular enzyme. In addition, partial enzyme activity of 63% compared with the extracellular enzyme activity was observed in membrane protein. The optimal pH and temperature of the ${\alpha}$-D-mannosidase were pH 7.5 and $37^{\circ}C$, respectively. The $K_m$ and $V_{max}$ values of the ${\alpha}$-D-mannosidase in crude enzyme toward p-nitrophenyl-${\alpha}$-D-mannopyranoside were determined to be $455.6{\mu}M$ and $10.8{\mu}mole/min/mg$ of protein, respectively. To the best of our knowledge, this is the first report described the alkaline ${\alpha}$-D-mannosidase from the family of B. safensis.

• Journal of Biosystems Engineering
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• 제34권5호
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• pp.331-341
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• 2009

A double-end rod hydraulic cylinder is widely used with a steering valve for the steering control system in large tractors. For the development of automatic steering controller, the feasibility of using a proportional control valve replacing the conventional manual steering valve to control the position of hydraulic steering cylinder was investigated in terms of the max. overshoot, the steady-state error and the rise time. A simulation model for the electrohydraulic steering system with load using AMESim package was developed to be valid so that the proper control algorithm could be chosen through the computer simulation. It could be concluded that the P-control algorithm was sufficient to control the electrohydraulic steering system, where the control frequency should be no greater than 20 Hz at the P-gain of 5. In particular, the performance of the developed steering controller was satisfactory even at the conditions of varying flow rates and loads.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권1호
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• pp.27-31
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• 2003

Infectious flacherie of silkworm Bombyx mori is caused by B. mori infectious flacherie virus (BmIFV) and causes severe crop loss to sericulturists. In the present study, a colloidal textile dye-based dipstick immunoassay is developed for the detection of infectious flacherie in silkworms. Colloidal textile dye (blue D2R) with Aλ$_{max}$ at 620 nm was sensitised with 500 $\mu\textrm{g}$/ml of purified anti-BmIFV IgG. The dye-antibody reagent detects purified antigen up to 10 ng/ml and BmIFV infection in diseased larval extracts $(up to a dilution of {10^-5})$ and faecal matter extracts $(up to a dilution of {10^-2})$ by forming clear blue dot within 30 min. It was observed to be stable for three months period at $4^{\circ}C$. The efficacy of textile dye-based dipstick immunoassay was on pay with HRP-based dipstick immunoassay and fluorescent antibody test, and better than latex agglutination and ouchterlony tests in the detection of BmIFV The dye-based dipstick immunoassay method provides a simple, sensitive and less expensive test for the detection of BmIFV infection in silkworms.s.