• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.276-285
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• 2022

This study evaluated the effect of lactic acid bacteria (LAB, a mixture of Enterococcus faecium and Lactobacillus plantarum) supplementation, the storage temperature, and storage period on the fermentation characteristics and in vitro ruminal digestibility of a total mixed ration (TMR). The TMR was prepared into two groups, namely, CON (control TMR without the LAB) and ML (supplementing a mixture of E. faecium and L. plantarum in the ratio of 1% and 2% (v/w), respectively). Both groups were divided and stored at 4℃ or 25℃ for 3, 7, and 14 d fermentation periods. Supplementing LAB to the TMR did not affect the chemical composition of TMR except for the lactate and acetate concentration. Storage temperatures affected (p<0.05) the chemical composition of the TMR, including pH, lactate, and acetate contents. The chemical composition of TMR was also affected (p<0.05) by the storage period. During in vitro rumen fermentation study, the ML treatment showed lower (p<0.05) dry matter digestibility at 24 h incubation with a higher pH compared to the CON. There was no difference in the in vitro dry matter digestibility (IVDMD) of TMR between the CON and ML treatment however, at 24 h, ML treatment showed lower (p<0.05) IVDMD with a higher pH compared to the CON. The effects of storage temperature and period on IVDMD were not apparent at 24 h incubation. In an in vivo study using Holstein steers, supplementing LAB to the basal TMR for 60 d did not differ in the final body weight and average daily gain. Likewise, the fecal microbiota did not differ between CON and ML. However, the TMR used for the present study did include a commercial yeast in CON, whereas ML did not; therefore, results were, to some extent, compromised in examining the effect of LAB. In conclusion, storage temperature and period significantly affected the TMR quality, increasing acetate and lactate concentration. However, the actual effects of LAB supplementation were equivocal.

• Korean Journal of Radiology
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• v.24 no.7
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• pp.647-659
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• 2023

Objective: The study was conducted to investigate the effect of correct occlusion of the left atrial appendage (LAA) on intracardiac blood flow and thrombus formation in patients with atrial fibrillation (AF) using four-dimensional (4D) flow magnetic resonance imaging (MRI) and three-dimensional (3D)-printed phantoms. Materials and Methods: Three life-sized 3D-printed left atrium (LA) phantoms, including a pre-occlusion (i.e., before the occlusion procedure) model and correctly and incorrectly occluded post-procedural models, were constructed based on cardiac computed tomography images from an 86-year-old male with long-standing persistent AF. A custom-made closed-loop flow circuit was set up, and pulsatile simulated pulmonary venous flow was delivered by a pump. 4D flow MRI was performed using a 3T scanner, and the images were analyzed using MATLAB-based software (R2020b; Mathworks). Flow metrics associated with blood stasis and thrombogenicity, such as the volume of stasis defined by the velocity threshold ($\left|\vec{V}\right|$ < 3 cm/s), surface-and-time-averaged wall shear stress (WSS), and endothelial cell activation potential (ECAP), were analyzed and compared among the three LA phantom models. Results: Different spatial distributions, orientations, and magnitudes of LA flow were directly visualized within the three LA phantoms using 4D flow MRI. The time-averaged volume and its ratio to the corresponding entire volume of LA flow stasis were consistently reduced in the correctly occluded model (70.82 mL and 39.0%, respectively), followed by the incorrectly occluded (73.17 mL and 39.0%, respectively) and pre-occlusion (79.11 mL and 39.7%, respectively) models. The surfaceand-time-averaged WSS and ECAP were also lowest in the correctly occluded model (0.048 Pa and 4.004 Pa^-1, respectively), followed by the incorrectly occluded (0.059 Pa and 4.792 Pa^-1, respectively) and pre-occlusion (0.072 Pa and 5.861 Pa^-1, respectively) models. Conclusion: These findings suggest that a correctly occluded LAA leads to the greatest reduction in LA flow stasis and thrombogenicity, presenting a tentative procedural goal to maximize clinical benefits in patients with AF.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.222-222
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• 2012

Metal oxide gas sensors based on semiconductor type have attracted a great deal of attention due to their low cost, flexible production and simple usability. However, most works have been focused on n-type oxides, while the characteristics of p-type oxide gas sensors have been barely studied. An investigation on p-type oxides is very important in that the use of them makes possible the novel sensors such as p-n diode and tandem devices. Monoclinic cupric oxide (CuO) is p-type semiconductor with narrow band gap (~1.2 eV). This is composed of abundant, nontoxic elements on earth, and thus low-cost, environment-friendly devices can be realized. However, gas sensing properties of neat CuO were rarely explored and the mechanism still remains unclear. In this work, the neat CuO layers with highly ordered mesoporous structures were prepared by a template-free, one-pot solution-based method using novel ink solutions, formulated with copper formate tetrahydrate, hexylamine and ethyl cellulose. The shear viscosity of the formulated solutions was 5.79 Pa s at a shear rate of 1 s-1. The solutions were coated on SiO2/Si substrates by spin-coating (ink) and calcined for 1 h at the temperature of $200{\sim}600^{\circ}C$ in air. The surface and cross-sectional morphologies of the formed CuO layers were observed by a focused ion beam scanning electron microscopy (FIB-SEM) and porosity was determined by image analysis using simple computer-programming. XRD analysis showed phase evolutions of the layers, depending on the calcination temperature, and thermal decompositions of the neat precursor and the formulated ink were investigated by TGA and DSC. As a result, the formation of the porous structures was attributed to the vaporization of ethyl cellulose contained in the solutions. Mesoporous CuO, formed with the ink solution, consisted of grains and pores with nano-meter size. All of them were strongly dependent on calcination temperature. Sensing properties toward H2 and C2H5OH gases were examined as a function of operating temperature. High and fast responses toward H2 and C2H5OH gases were discussed in terms of crystallinity, nonstoichiometry and morphological factors such as porosity, grain size and surface-to-volume ratio. To our knowledge, the responses toward H2 and C2H5OH gases of these CuO gas sensors are comparable to previously reported values.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• Korean Journal of Optics and Photonics
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• v.25 no.6
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• pp.334-339
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• 2014

In this paper, the optical properties of a miniature telecentric camera are studied analytically and experimentally. By means of optical properties, the luminous intensity of retro-reflection of a miniature telecentric optical system is investigated. First, from a simulation the theoretical value of the coefficient of luminous intensity of retro-reflection of a miniature telecentric system is estimated. Second, a miniature telecentric camera device is designed, and the value of the coefficient of luminous intensity of retro-reflection of the actual device is measured through experiment. From simulation and experiment, we found that both the estimated and observed values of the coefficient of luminous intensity of retro-reflection range from 0.002 to $0.03m^2/sr$ (P384200CPH: $0.0042-0.018m^2/sr$, P285200CPH: $0.0045-0.0297m^2/sr$, P321450S: $0.0021-0.00963m^2/sr$) at 1.4 to 4.9 arcminute. The results prove the significance of the mechanisms used to design the miniature telecentric camera, and the experimental method. Accordingly, with these significant results, this study contributes to the development of theory and practice in optical engineering science.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.58-66
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• 2007

Isolation, expression, and characterization of a novel $endo-{\beta}-1,3(4)-D-glucanase$ with high specific activity and homology to Bacillus lichenases is described. One clone was screened from a genomic library of Paenibacillus sp. F-40, using lichenan-containing plates. The nucleotide sequence of the clone contains an ORF consisting of 717 nucleotides, encoding a ${\beta}-glucanase$ protein of 238 amino acids and 26 residues of a putative signal peptide at its N-terminus. The amino acid sequence showed the highest similarity of 87% to other ${\beta}-1,3-1,4-glucanases$ of Bacillus. The gene fragment Bg1 containing the mature glucanase protein was expressed in Pichia pastoris at high expression level in a 3-1 high-cell-density fermenter. The purified recombinant enzyme Bg1 showed activity against barley ${\beta}-glucan$, lichenan, and laminarin. The gene encodes an $endo-{\beta}-1,3(4)-D-glucanase$ (E. C. 3.2.1.6). When lichenan was used as substrate, the optimal pH was 6.5, and the optimal temperature was $60^{\circ}C$. The $K_m,\;V_{max},\;and\;k_{cat}$ values for lichenan are 2.96mg/ml, $6,951{\mu}mol/min{\cdot}mg,\;and\;3,131s^{-1}$, respectively. For barley ${\beta}-glucan$ the values are 3.73mg/ml, $8,939{\mu}mol/min{\cdot}mg,\;and\;4,026s^{-1}$, respectively. The recombinant Bg1 had resistance to pepsin and trypsin. Other features of recombinant Bg1 including temperature and pH stability, and sensitivity to some metal ions and chemical reagents were also characterized.

• Journal of Pharmaceutical Investigation
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• v.39 no.1
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• pp.65-71
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• 2009

The aim of the present study was to evaluate the bioequivalence of two domperidone maleate tablets, Motilium-$M^{(R)}$ Tablet (Janssen Korea Ltd., reference product) and $Toriem^{(R)}$ Tablet (Daewon Pharm. Co., Ltd., test product). Domperidone was extracted by liquid-liquid extraction using tert-butyl methyl ether and separated in less than 3 min on $C_{18}$ reverse-phase column using an isocratic elution. A tandem mass spectrometer, as detector, was used for quantitative analysis in positive mode by a multiple reaction monitoring mode to monitor the m/z $426.1{\rightarrow}119.1$ and the m/z $837.4{\rightarrow}158.2$ transitions for domperidone and the internal standard (roxithromycin), respectively. Calibration curves, from $0.05{\sim}50$ ng/mL of domperidone, showed correlation coefficients (r) higher than 0.9941. Intra day and inter day precision (C.V. %) for quality control were ranged from 10.04 to 16.09% and from 10.87 to 18.69%, respectively. The lower limit of quantification (LLOQ) of domperidone was 0.05 ng/mL. The method described is precise and sensitive and has been successfully applied to the study of bioequivalence of domperidone in 24 healthy Korean volunteers. Twenty-four healthy male Korean volunteers received a single dose of each medicine ($2{\times}12.72\;mg$ domperidone maleate) in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of domperidone were monitored for over a period of 24 hr after the administration. $AUC_{0-t}$ (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. The 90% confidence intervals for the log transformed data were within acceptable range of log 0.8 to log 1.25 (e.g., $log\;0.92{\sim}log\;1.05$ for $AUC_{0-t}$, $log\;0.81{\sim}log\;1.05$ for $C_{max}$). The major parameters, $AUC_{0-t}$ and $C_{max}$ met the criteria of KFDA for bioequivalence indicating that $Toriem^{(R)}$ tablet is bioequivalent to Motilium-$M^{(R)}$ tablet.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.896-904
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• 2001

Conjugated linoleic acid(CLA) is a group of positional and geometric isomers of linoleic acid(LA) and exhibits anticarcinogenic activity in multiple experimental animal models. Cis-9,trns-11(c9t11) and trans-10,cis-12(t10c12) CLA are the principal isomers found in foods. The present study was performed to determine whether CLA and the two isomers inhibits HT-29 cell proliferation and to assess whether such an effect was related to changes in secretion of eicosanoids. Cells were incubated in serum-free medium with various concentrations(0 to 20$\mu$M) of CLA or LA. CLA inhibited cell proliferation in a dose-dependent manner, with maximal inhibition(70 $\pm$ 1%) observed at 20$\mu$M concentration after 96 hours. However, LA had no effect at the same concentration range. To compare the ability of c9f11 and t10c12 to inhibit cell proliferation, cells were incubated with increasing concentrations(0 to 4$\mu$M) of these isomers. T10c12 inhibited cell proliferation in a dose-dependent manner. A 66 $\pm$ 2% decrease in cell number was observed within 96 hours after addition of 4$\mu$M t10c12. By contrast, c9t11 had no effect. The concentrations of CLA and the two isomers in the plasma membrane were increased when they were added to the incubation medium. However, they did not alter the levels of arachidonic acid in plasma membrane. To assess whether the proliferation inhibiting effect of CLA was related to changes in eicosanoid production, prostaglandin E$_2$(PGE$_2$) and leukotriene B$_4$(LTB$_4$) concentrations in conditioned media were estimated by a competitive enzyme immunoassay. Both CLA and t10c12 increased the production of materials reactive to PGE$_2$ and LTB$_4$ antibodies in a dose-dependent manner. By contrast, c9t11 had no effect. These results indicate that inhibition of HT-29 cell proliferation by CLA is attributed to the effect of the t10v12 isomer. The materials reactive to PGE$_2$ and LTB$_4$ antibodies may inhibit growth stimulatory effect of arachidonic acid-derived eicosanoids on HT-29 cell proliferation.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.606-612
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• 2018

The enzyme xylose isomerase (E.C. 5.3.1.5, XI) is responsible for the conversion of an aldose to ketose, especially xylose to xylulose. Owing to the ability of XI to isomerize glucose to fructose, this enzyme is used in the food industry to prepare high-fructose corn syrup. Therefore, we studied the characteristics of XI from Anoxybacillus kamchatkensis G10, a thermophilic bacterium. First, the gene coding for XI (xylA) was inserted into the pET-21a(+) expression vector and the construct was transformed into the Escherichia coli competent cell BL21 (DE3). The expression of recombinant XI was induced in the absence of isopropyl-thio-${\beta}$-galactopyranoside and purified using Ni-NTA affinity chromatography. The optimum temperature of recombinant XI was $80^{\circ}C$ and measurement of the heat stability indicated that 55% of residual activity was maintained after 2 h incubation at $60^{\circ}C$. The optimum pH was found to be 7.5 in sodium phosphate buffer. Magnesium, manganese, and cobalt ions were found to increase the enzyme activity; manganese was the most effective. Additionally, recombinant XI was resistant to the presence of $Ca^{2+}$ and $Zn^{2+}$ ions. The kinetic properties, $K_m$ and $V_{max}$, were calculated as 81.44 mM and $2.237{\mu}mol/min/mg$, respectively. Through redundancy analysis, XI of A. kamchatkensis G10 was classified into a family containing type II XIs produced by the genera Geobacillus, Bacillus, and Thermotoga. These results suggested that the thermostable nature of XI of A. kamchatkensis G10 may be advantageous in industrial applications and food processing.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.77-90
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• 2009

Near Infrared Reflectance Spectroscopy(NIRS) is a quick, accurate, and non-destructive method to measure multiple nutrient components in plant leaves. This study was to acquire a liner regression equation by evaluating the nutrient contents of 'CY2' creeping bentgrass rapidly and accurately using NIRS. In particular, nitrogen fertility is a primary element to keep maintaining good quality of turfgrass. Nitrogen, moisture, carbohydrate, and starch were assessed and analyzed from 'CY2' creeping bentgrass clippings. A linear regression equation was obtained from accessing NIRS values from NIR spectrophotometer(NIR system, Model XDS, XM-1100 series, FOSS, Sweden) programmed with WinISI III project manager v1.50e and ISIscan(R) (Infrasoft International) and calibrated with laboratory values via chemical analysis from an authorized institute. The equation was formulated as MPLS(modified partial least squares) analyzing laboratory values and mathematically pre-treated spectra. The accuracy of the acquired equation was confirmed with SEP(standard error of prediction), which indicated as correlation coefficient($r^2$) and prediction error of sample unacquainted, followed by the verification of model equation of real values and these monitoring results. As results of monitoring, $r^2$ of nitrogen, moisture, and carbohydrate in 'CY2' creeping bentgrass was 0.840, 0.904, and 0.944, respectively. SEP was 0.066, 1.868, and 0.601, respectively. After outlier treatment, $r^2$ was 0.892, 0.925, and 0.971, while SEP was 0.052, 1.577, and 0.394, respectively, which totally showed a high correlation. However, $r^2$ of starch was 0.464, which appeared a low correlation. Thereof, the verified equation appearing higher $r^2$ of nitrogen, moisture, and carbohydrate showed its higher accuracy of prediction model, which finally could be put into practical use for turf management system.