• Journal of Microbiology
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• v.38 no.4
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• pp.245-249
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• 2000

Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae Bl are intertwined, joining at the level of substituted benzoates, which are further degraded vita ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy.S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae Bl grown on benzoate has both catechol orthoand meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

• The Korean Journal of Emergency Medical Services
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• v.27 no.1
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• pp.101-111
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• 2023

Purpose: This study aimed to provide basic information for university students to improve disaster preparedness by identifying disaster and safety cognition, safety education perception and identifying factors influencing disaster preparedness. Methods: Selected articles were programmed statistically by SPSS to analyze 162 third and fourth-year students in Chungcheong-do, from December 1, 2022 to December 31, 2022. The general characteristics of the subject with the effect of disaster and safety cognition, safety education perception, and disaster preparedness was analyzed by t-test and ANOVA. Results: Disaster preparedness had a positive correlation with Disaster and safety cognition (r=.499, p<.001) and safety education perception (r=.328, p<.001). Furthermore, the influencing factors on disaster preparedness were sex (β=0.17, p<.011), disaster and safety cognition (β=0.39, p<.001), and 28% was explanatory power. Conclusion: Preparing educational method for strengthening safety and disaster cognition requires improving the disaster preparedness of university students, and a new educational approach to program development to elevate disaster and safety cognition at the university level.

• Journal of Korean Vacuum Science & Technology
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• v.4 no.4
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• pp.93-96
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• 2000

Microchannel plates (MCPs) have been developed by introducing new materials and process technologies. Main body was made of alumina by programmable punching, laminating, and firing. The channel walls of pore arrays of an MCP were deposited with thin films by electroless copper plating and sol-gel process. Our MCP has advantages such as easy fabrication, durability, high temperature endurance, and applicability to the large size comparing with the conventional MCPs. Experiments on the brightness of an MCP incorporated FED revealed that the FED with a MCP is three to four times brighter than a conventional FED. Moreover, the focusing in a FED is improved. Incorporating an MCP into a FED is one of promising methods to enhance the characteristics of the FED. In addition, amplification yield of the MCP is measured for varying the aspect ratio and the input current.

• Toxicological Research
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• v.19 no.3
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• pp.173-180
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• 2003

The present study was conducted to investigate the single and 2-week repeated dose toxicity of red ginseng acidic polysaccharide (RGAP) in Sprague-Dawley rats. The test article was administered orally to rats at dose levels of 0, and 2000 mg/kg/day for single dose toxicity study and at dose levels of 0, 250, 500, and 1000 mg/kg/day for repeated dose toxicity study. In both studies, there were no treatment-related effects on mortality, clinical signs, food and water consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, necropsy findings and organ weights of all animals treated RGAP. Based on these results, it was concluded that the 2-week repeated oral dose of RGAP may have no toxic effect in rats at a dose level of 1000 mg/kg/day. In the condition of this study, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day for both sexes.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1124-1131
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• 2020

Techniques used for the regulation of gene expression facilitate studies of gene function and treatment of diseases via gene therapy. Many tools have been developed for the regulation of gene expression in mammalian cells. The Lac operon system induced with isopropyl β-D-1-thiogalactopyranoside (IPTG) is one of the employed inducible systems. IPTG mimics the molecular structure of allolactose and has a strong affinity for the corresponding repressor. IPTG is known to rapidly penetrate into mammalian cells and exhibits low toxicity. In the present study, we developed a new inducible expression system that could regulate the expression of genes in mammalian cells using IPTG. Here we confirm that unlike other vector systems based on the Lac operon, this expression system allows regulation of gene expression with lactose in the mammalian cells upon transfection. The co-treatment with IPTG and lactose could improve the regulatory efficiency of the specific target gene expression. The regulation of gene expression with lactose has several benefits. Lactose is safe in humans as compared to other chemical substances and is easily available, making this technique very cost-effective.

• Journal of Computing Science and Engineering
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• v.9 no.2
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• pp.83-97
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• 2015

IEEE 802.15.4 is a global standard designed for emerging applications in low-rate wireless personal area networks (LR-WPANs). The standard provides beneficial features, such as a beacon-enabled mode and guaranteed time slots for realtime data delivery. However, how to optimally operate those features is still an open issue. For the optimal operation of the features, this paper proposes a holistic optimization method that jointly optimizes three cross-related problems: cluster-tree construction, nodes' power configuration, and duty-cycle scheduling. Our holistic optimization method provides a solution for those problems so that all the real-time packets can be delivered within their deadlines in the most energy-efficient way. Our simulation study shows that compared to existing methods, our holistic optimization can guarantee the on-time delivery of all real-time packets while significantly saving energy, consequently, significantly increasing the lifetime of the network. Furthermore, we show that our holistic optimization can be extended to take advantage of the spatial reuse of a radio frequency resource among long distance nodes and, hence, significantly increase the entire network capacity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1157-1163
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• 2000

In this paper, we present a novel and practical stereo vision system that uses only one camera and four mirrors placed in front of the camera. The equivalent of a stereo pair of images are formed as left and right halves of a single CCD image by using four mirrors placed in front of the ten of a CCD camera. An object arbitrary point in 3D space is transformed into two virtual points by the four mirrors. As in the conventional stereo system, the displacement between the two conjugate image points of the two virtual points is directly related to the depth of the object point. This system has the following advantages over traditional two camera stereo that identical system parameters, easy calibration and easy acquisition of stereo data.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.369-374
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• 2008

A neutered male, 8-year-old, Pekingese, weighing 4.3 kg with a history of anorexia, sneezing, nasal discharge, and epistaxis for one month was referred. Soft tissue swelling around the nasal bone and small defects of the hard palate with a tiny round dark red mass were found on physical examination. The laboratory tests represented mild leukocytosis. On skull radiographs, soft tissue swelling and osteolytic change of the incisor bone, nasal bone, and maxilla were found. On computed tomography scan images, there was soft tissue attenuating opacity with calcified spots in the bilateral nasal cavities and frontal sinuses. Loss of nasal turbinate pattern and nasal septum was found. And destruction of the insicor bone, nasal bone, maxilla, hard palate, perpendicular palatine bone, and cribriform plate were identified. Nasal malignant melanoma was confirmed by nasal biopsy.

• English Language & Literature Teaching
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• v.18 no.2
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• pp.213-246
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• 2012

This study aims to investigate how the EBS English (EBSe) After-School program has been implemented in after-school classrooms. It also aims to examine the needs of the teachers and the students involved in the program, as well as their evaluation of the program itself to date. The EBSe After-School program has recently been launched and used in public school contexts less than a year. Thus, it is necessary to examine ways how the EBSe After-School program has been applied in real after-schools; and how the program has been perceived by the people engaged. The study was conducted in 19 elementary schools and 12 middle schools, which ran their after-school classes utilizing the EBSe program. Questionnaires were given to the 52 teachers and 1,258 students using the program. In addition to the questionnaires, syllabi and lesson plans of the after-school classes have also been inspected. The study finds that, despite overall satisfaction with the program, only a small portion of students participated in the after-school classes. Another finding of the study is that there was much difference in the way of implementing the program between the elementary and middle schools. Finally, the study makes some suggestions for improving the program.

• BMB Reports
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• v.48 no.7
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• pp.371-372
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• 2015

MicroRNAs (miRNAs) can regulate the expression of genes that are involved in multiple cellular pathways. However, their targets and mechanism of action associated with the autophagy pathway are not fully investigated yet. EWSR1 (EWS RNA-Binding Protein 1/Ewing Sarcoma Break Point Region 1) gene encodes a RNA/DNA binding protein that is ubiquitously expressed and plays roles in numerous cellular processes. Recently, our group has shown that EWSR1 deficiency leads to developmental failure and accelerated senescence via processing of miRNAs, but its role in the regulation of autophagy remains elusive. In this context, we further investigated and found that EWSR1 deficiency triggers the activation of the DROSHA-mediated microprocessor complex and increases the levels of miR125a and miR351, which directly target Uvrag. Interestingly, the miR125a- and miR351-targeted reduction of Uvrag led to the inhibition of autophagy in both ewsr1 knockout (KO) MEFs and ewsr1 KO mice. In summary, our study demonstrates that EWSR1 is associated with the posttranscriptional regulation of Uvrag via miRNA processing. The regulation of autophagy pathway in miRNAs-Uvrag-dependent manner provides a novel mechanism of EWSR1 deficiency-related cellular dysfunction. [BMB Reports 2015; 48(7): 371-372]