• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.4
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• pp.362-368
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• 2023

Multilayered actuators using Pb(Mg_1/3Nb_2/3)O₃-Pb(In_1/2Nb_1/2)O₃-PbTiO₃ (PMN-PIN-PT) crystals have demonstrated excellent properties, but are costly and lack mechanical strength. Textured PMN-PIN-PT ceramics exhibit robust mechanical strength and comparable properties to their single crystals form. However, the development of multilayered actuators using textured PMN-PIN-PT ceramics has not been achieved until now. This study presents the development of a multilayered actuator using textured 0.37PMN-0.29PIN-0.34PT ceramics with an Ag_0.9/Pd_0.1 inner electrode, co-fired at 950℃. A random 0.37PMN-0.29PIN-0.34PT ceramics multilayered actuator was also developed for comparison. The multilayered actuator consisted of 9 ceramic layers (36 ㎛ thickness) with an overall actuator thickness of 0.401 mm. The textured and random 0.37PMN-0.29PIN-0.34PT ceramics-based multilayered actuators achieved displacements of 0.61 ㎛ (0.15% strain) and 0.23 ㎛ (0.057% strain) at a low applied peak voltage of 100 V. These results suggest that the developed multilayered actuator using high-performance textured 0.37PMN-0.29PIN-0.34PT ceramics has the potential to replace expensive single crystal-based actuators cost-effectively.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.176-189
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• 2020

Purpose To evaluate the clinical efficacy of real-time sonoelastography (RTS) for the follow-up of congenital muscular torticollis, based on measurements of muscle elasticity. Materials and Methods Thirty-four infants (23 male, 11 female) with congenital sternocleidomastoid (SCM) muscle torticollis underwent ultrasonography and elastography between November 2012 and December 2014. We evaluated the thickness, morphology (mass-like, fusiform, or overall thickened shape), and echogenicity of the SCM muscle on grayscale images and color patterns (homogeneous blue, mixed green < 50% and ≥ 50%, and green to red) on elastography. Strain ratios were measured using Q-lab software. A clinician classified the degree of neck rotation and side flexion deficits using a 5-point grade system based on angles of neck rotation and side flexion. Correlations between the ultrasonography and clinical findings were evaluated by statistical analysis. Results Twenty-two infants had right and 12 had left SCM torticollis, respectively. Linear regression analysis showed that involved/contralateral SCM thickness differences, morphology, elasticity color scores, and strain ratios of the affected SCM muscles were significantly correlated with neck rotation and side flexion deficit scores (p < 0.05). The elasticity color score of the affected SCM muscle was the most significant factor. Conclusion RTS might provide a reliable means for evaluating and monitoring congenital muscular torticollis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.88-96
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• 2009

This study proposes a wireless measurement system that is a new safety management system by using an FBG sensor and a PDA. The sensor part has many advantages of implementing a wireless measurement system, and the study emploies an FBG-LVDT sensor, FBG-STRAIN sensor, FBG-TEMP sensor, and FBG-ACC sensor, using FBG sensors. Also, the study show a configuration of a signal process system for operating a wireless transmission system of FBG sensors applied to the signal process system, and engrafted the cutting edge information technology industry in order to display from a remote distance using a PDA. In order to verify the applicability of the developed FBG sensors and wireless measurement monitoring system to the field, their accuracy, and usability, the study has conducted a static and dynamic test to a bridge in the field. The study made an assessment of service for the vibration of the bridge by applying dynamic data measured by an FBG-LVDT sensor and FBG-ACC sensor to Meister's curve and prepared methods for assessing the vibration of the bridge by proposing a standard of vibration limitation given the service of vibration of the bridge. As a follow up for this study, it would be necessary to set up an overall model for the standard of service assessment established in this study.

• Journal of Korean Neurosurgical Society
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• v.46 no.6
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• pp.532-537
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• 2009

Objective : Recently, motion preservation has come to the forefront of emerging technologies in spine surgery. This is the important background information of the emergence of cervical arthroplasty as an alternative to arthrodesis that offers the promise of restoring normal spinal movement and reduces a kinematic strain on adjacent segments. The study was designed to evaluate early surgical outcome and radiological effects of $Bryan^{(R)}$ cervical disc prosthesis. Methods : The authors retrospectively reviewed radiographic and clinical outcomes in 52 patients who received the $Bryan^{(R)}$ Cervical Disc prosthesis, for whom follow-up data were available. Static and dynamic radiographs were measured by computer to determine the angles formed by the endplates of the natural disc preoperatively, those formed by the shells of the implanted prosthesis, the angle of functional spine unit (FSU), and the C2-7 Cobb angle. The range of motion (ROM) was also determined radiographically, whereas clinical outcomes were assessed using Odom's criteria, visual analogue pain scale (VAS) and neck disability index (NDI). Results : A total of 71 $Bryan^{(R)}$ disc were placed in 52 patients. A single-level procedure was performed in 36 patients, a two-level procedure in 13 patients, and a three-level procedure in 3. Radiographic and clinical assessments were made preoperatively. Mean follow-up duration was 29.2 months, ranging from 6 to 36 months. All of the patients were satisfied with the surgical results by Odom's criteria, and showed significant improvement by VAS and NDI score (p < 0.05). The postoperative ROM of the implanted level was preserved without significant difference from preoperative ROM of the operated level (p < 0.05). 97% of patients with a preoperative lordotic sagittal orientation of the FSU were able to maintain lordosis. The overall sagittal alignment of the cervical spine was preserved in 88.5% of cases at the final follow up. Interestingly, preoperatively kyphotic FSU resulted in lordotic FSU in 70% of patients during the late follow up, and preoperatively kyphotic overall cervical alignment resulted in lordosis in 66.6% of the patients postoperatively. Conclusion : Arthroplasty using the $Bryan^{(R)}$ disc seemed to be safe and provided encouraging clinical and radiologic outcome in our study. Although the early results are promising, this is a relatively new approach, therefore long-term follow up studies are required to prove its efficacy and its ability to prevent adjacent segment disease.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.221-228
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• 2004

Basic properties of artificial lightweight aggregate by using waste dusts and strength properties of LWA concrete were studied. Bulk specific gravity and water absorption of artificial lightweight aggregates varied from 1.4 to 1.7 and 13 to 16%, respectively. Crushing ratio of artificial lightweight aggregate was above 10% higher than that of crushed stone or gravel. As a result of TCLP leaching test, the leaching amount of tested heavy metal element was below the leaching standard of hazardous material. Slump, compressive strength and stress-strain properties of LWA concrete made of artificial lightweight aggregate were tested. Concrete samples derived from LWA substitution ratio of 30 vol% and W/C ratio of 45 wt% showed the best properties overall. Thermal insulation and sound insulation characteristics of light weight concrete panel with the optimum concrete proportion were tested. Average overall heat transmission of 3.293W/㎡$^{\circ}C$ was observed. It was higher by about 15% than those of normal concrete made by crushed stone. Sound transmission loss of 50.9 ㏈ in frequency of 500 ㎐ was observed. It was higher by about 13% than standard transmission loss.

• Animal Bioscience
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• v.37 no.5
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• pp.896-907
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• 2024

Objective: The potential of aqueous extract of Christ's thorn jujube (Ziziphus spina-christi) leaves (SLAE) to reduce the negative impacts of heat stress on production performance and physiological traits was investigated in dual-purpose layers under subtropical farming. Methods: A total of 200, 25-week-old laying hens (Inshas strain) were randomly assigned to four dietary treatments including SLAE at 0, 2.5, 5.0, and 7.5 mL/kg, respectively. The average temperature-humidity index value was 26.69 during the experimental period. The SLAE contained saponin (0.045%), total flavonoid content of 17.9 mg of quercetin equivalent/100 g and overall antioxidant capacity concentration of 17.9 mg of ascorbic acid equivalent/100 g. Results: The maximum final body weight (BW), BW gain, egg weight, number, and mass occurred at the level of SLAE7.5 inclusion. The egg quality was significantly higher in SLAE groups than in control, and overall, SLAE7.5 had the most favorable influence at 28 and 32 weeks. Liver and kidney function, as well as lipids profile, improved significantly by SLAE inclusion; the lowest concentrations of these parameters were in SLAE7.5 hens. Treatment with SLAE7.5 increased total antioxidant capacity and endogenous antioxidant enzymes compared to control, whereas no effect on superoxide dismutase was noticed. Conclusion: The addition of SLAE at 7.5 mL/kg diet improved egg laying performance and quality, metabolic profiles, and antioxidant status during hyperthermia conditions.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.339-345
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• 2009

We evaluated the activity and abundance of the crude-oil-degrading bacterium Nocardia sp. H17-1 during bioremediation of oil-contaminated soil, using real-time PCR. The total petroleum hydrocarbon(TPH) degradation rate constants(k) of the soils treated with and without H17-1 were $0.103\;d^{-1}$ and $0.028\;d^{-1}$ respectively. The degradation rate constant was 3.6 times higher in the soil with H17-1 than in the soil without H17-1. In order to detect and quantify the Nocardia sp. H17-1 in soil samples, we quantified the genes encoding 16S ribosomal RNA(16S rRNA), alkane monooxygenase(alkB4), and catechol 2,3-dioxygenase(23CAT) with real-time PCR using SYBR green. The amounts of H17-1 16S rRNA and alkB4 detected increased rapidly up to 1,000-folds for the first 10 days, and then continued to increase only slightly or leveled off. However, the abundance of the 23CAT gene detected in H17-1-treated soil, where H17-1 had neither the 23CAT gene for the degradation of aromatic hydrocarbons nor the catechol 2,3-dioxygenase activity, did not differ significantly from that of the untreated soil($\alpha$=0.05,p>0.22). These results indicated that H17-1 is a potential candidate for the bioaugmentation of alkane-contaminated soil. Overall, we evaluated the abundance and metabolic activity of the bioremediation strain H17-1 using real-time PCR, independent of cultivation.

• Mycobiology
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• v.40 no.2
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• pp.138-141
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• 2012

We measured physiological functionalities, including antihypertensive angiotensin I-converting enzyme inhibitory activity and immun-stimulating ${\beta}$-glucan content for sixty kinds of Makgeolli that is commercially available from the market. As a result, we selected R-12 commercial raw Makgeolli, with a high content of immuno-stimulating ${\beta}$-glucan, and R-14 commercial raw Makgeolli, exhibiting high antihypertensive activity. Due to the similarities in their overall physicochemical properties and raw materials used for fermentation, we compared the microbial flora in order to investigate the reason for the differences in their functionalities. Nested PCR and denaturing gradient gel electrophoresis for yeasts and bacteria were performed for analysis of microbial diversity of two different kinds of Makgeolli (i.e., R-12, R-14), which showed immuno-stimulating ${\beta}$-glucan content and exhibited a very high level of antihypertensive activity, respectively. Analysis of the 18S rDNA amplicon revealed a major presence of the yeast strain Pichia burtonii in every Makgeolli sample. Analysis of the 16S rDNA amplicon revealed a predominance of lactic acid bacteria, and the most frequent lactic acid bacteria were Lactobacillus ingluviei, L. fermentum, and L. harbinensis, and Lactobacillus sp. Among these, L. harbinensis was detected only in R-12 and L. ingluviei was found only in R-14. Different functionalities from the individual commercially available Makgeolli may be attributed to actions of different microbial flora during fermentation.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.745-752
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• 2015

Tuberculosis (TB) is the most common mycobacterial infection in developing countries, requiring a rapid, accurate, and well-differentiated detection/diagnosis. For the rapid detection and discrimination of Mycobacterium tuberculosis complex (MTC) from non-tuberculous mycobacteria (NTM), a novel, simple, and primer-combined single-step multiplex PCR using three primer pairs (6110F-6110R, 1081F-1081R, and 23SF-23SR; annealing on each of IS6110, IS1081, and 23S rDNA targets), hereafter referred to as a triplex PCR, has been developed and evaluated. The expected product for IS6110 is 416 bp, for IS1081 is 300 bp, and for 23S rDNA is 206 bp by single PCR, which was used to verify the specificity of primers and the identity of MTC using DNA extracted from the M. tuberculosis H37Rv reference strain (ATCC, USA) and other mycobacteria other than tuberculosis (MOTT) templates. The triplex PCR assay showed 100% specificity and 96% sensitivity; the limit of detection for mycobacteria was ~100 fg; and it failed to amplify any target from DNA of MOTT (50 samples tested). Of 307 blinded clinical samples, overall 205 positive M. tuberculosis samples were detected by single PCR, 142 by conventional culture, and 90 by AFB smear methods. Remarkably, the triplex PCR could subsequently detect 55 positive M. tuberculosis from 165 culture-negative and 115 from 217 AFB smear-negative samples. The triplex PCR, targeting three regions in the M. tuberculosis genome, has proved to be an efficient tool for increasing positive detection/discrimination of this bacterium from clinical samples.

• Journal of Mushroom
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• v.13 no.1
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• pp.41-49
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• 2015

In order to breed new strains of oak mushroom, Lentinula edodes, on the sawdust cultivation, we collected 10 from Korea, Taiwan and China respectively and examined somatic incompatibility, morphological features of fruiting body and productivity. Four strains(SANJO701HO, FMRI2534, FMRI2337 and FMRI2613) shown remarkable results, were confirmed with parental strains. 80 monokaryotic strains derived from the selected 4 parental strains, were selected and 117 hybrid strains were made by mono-mono mating. Aslo, Physiological characteristics were investigated. Average of the mycelial growth of hybrid strains of mating combination SANJO701HO-FMRI2337 was approximately 10% lower than other mating combinations. Overall, This study was founded to develop new varieties of L. edodes. The productivity of new 117 strains on sawdust cultivation needs continued research.