• Biomedical Science Letters
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• v.26 no.3
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• pp.149-156
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• 2020

We developed a simple and rapid method for detecting vancomycin resistance genes, such as vanA and vanB, using loop-mediated isothermal amplification (LAMP). To identify not only vancomycin resistance genes, but also the genus Enterococcus, primers were designed for vanA, vanB, and 16S rRNA. Screening for vancomycin susceptibility in Enterococcus was performed using Etest (bioMérieux Inc). The results of the LAMP assay were compared to those of real-time RT-PCR. The optimal conditions for the LAMP assay were 65℃ for 60 min. The detection limits of the LAMP assay for vanA, and vanB were 2 × 10² copies/reaction. Compared to RT-PCR, the sensitivities and specificities of LAMP for 16S rRNA, vanA, and vanB were 100/100%, 100/100%, and 100/100%, respectively. The vanA genotype-vanB phenotype accounted for 57.5% (46/80) of the vancomycin-resistant Enterococci samples collected from 2016 to 2019. In conclusion, the LAMP assay developed in this study showed high sensitivity and specificity for vancomycin-resistant genes. Moreover, due to the simplicity and rapidity of the LAMP assay, its use can be very useful in clinical microbiology laboratories.

• YAKHAK HOEJI
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• v.55 no.1
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• pp.11-15
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• 2011

Zabofloxacin is a novel broad spectrum fluoroquinolone with excellent anti-pneumococcal activity. We investigated the in vitro activity of zabofloxacin against clinical isolates of gram-positive bacteria and the in vivo activity against systemic infection in mice. Zabofloxacin was very active against gram-positive bacteria except QRSA (Quinolone-resistant S. aureus) and VRE(Vancomycin-resistant Enterococci). Especially, zabofloxacin was extremely potent against clinical isolates of Streptococci. Zabofloxacin was as active as gemifloxacin against systemic infection in mice. In view of its improved antibacterial activities against gram-positive bacteria and good pharmacokinetic profiles in animals, the clinical usefulness of zabofloxacin should be established by further studies.

• Biomedical Science Letters
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• v.18 no.1
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• pp.83-85
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• 2012

Vancomycin-resistant (VR)-E. faecium and VR-E. faecalis were isolated simultaneously from a rectal swab of a patient diagnosed with pneumonia in an intensive care unit (ICU). The patient was treated with various antibiotics including vancomycin. Only VR-E. faecium was continually isolated from the rectal swab at one and two weeks of the treatment. Identical vanA, IS1216V, and IS1542 genes were detected in both VR-E. faecium and VR-E. faecalis isolates which showed equal resistance against vancomycin and teicoplanin, but IS1251 was not detected. VR-E. faecium showed stronger multi-drug resistance than VE-E. faecalis. This result supports the reason why VR-E. faecium is one of the major pathogens in nosocomial infections.

• Journal of Integrative Natural Science
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• v.10 no.3
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• pp.154-161
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• 2017

An antimicrobial peptides-producing Bacillus strain CBS73 was isolated from fermented food (kimchi) that produces low-molecular-weight proteins with broad-spectrum antimicrobial activity. Our goal was to explore the therapeutic potential of antimicrobial substances produced by Bacillus species. Peptide CBS73 was purified from Bacillus subtilis subsp. subtilis with identity of 99.79%. It was found to be stable at pH 4.0-10.0 and temp $20-60^{\circ}C$. A protein band around 5.2 kDa was detected in tricine-SDS-PAGE and band was confirmed by MALDI-TOF test. Peptide CBS73 showed antimicrobial activity against MDR bacteria. The minimal inhibitory concentration (MIC) of peptide CBS73 for vancomycin-resistant S. aureus (VRSA), vancomycin resistant Enterococci (VRE) and Salmonella typhimurium ranged from $10-40{\mu}g/mL$. The antioxidant activity of peptide CBS73 was measured by DPPH scavenging, reducing power activity and total phenolic content. Cell viability and NO production result showed less cytotoxic effect upto $12{\mu}g/mL$. Peptide CBS73 could be a promising antimicrobial agent for clinical application.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.3
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• pp.268-276
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• 2015

Purpose: The purpose of this study was to identify factors which influence the management of MultiDrug -Resistant Organisms (MDROs) by nurses in Intensive Care Units (ICUs). Methods: Data were collected from December 8 to 20, 2013 and participants were 163 ICU nurses working in one general hospital. The Health Belief Model tool and knowledge and management of MDROs infection tools were used in the study. Descriptive statistics, t-test, analysis of variances, Pearson correlation coefficients and multiple regression were used to analyze the data. Results: Knowledge, perceived susceptibility, and perceived benefits had a significant influence on MRSA (Methicillin Resistant Staphylococcus Aureus,) and MDRAB (Multidrug Resistant Acinetobacter Baumannii) infection management when all the other variables were considered. Significant variable which had influence on VRE (Vancomycin Resistant Eenterococci) infection management were perceived susceptibility and perceived benefits. Conclusion: Perceived susceptibility and perceived benefits had significant influence on MDROs infection management. Emphasis needs to be on the perceived susceptibility and perceived benefits of MDROs infection management when providing an educational program for ICU nurses.

• Journal of Wind Energy
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• v.9 no.4
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• pp.47-56
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• 2018

This paper introduces an active power dependent standard characteristic curve, Q(P) to compensate for voltage variations due to the output of distributed generation. This paper presents an efficient control method of grid-connected inverters by comparing and analyzing voltage variation magnitude and line loss according to the compensation method. Voltage variations are caused not only by active power, but also by the change of reactive power flowing in the line. In particular, the system is in a relatively remote place in a coastal area compared with existing power plants, so it is relatively weak and may not be suitable for voltage control. So, since it is very important to keep the voltage below the normal voltage limit within the specified inverter capacity and to minimize line loss due to the reactive power. we describe the active power dependent standard characteristic curve, Q(P) method and verify the magnitude of voltage variation by simulation. Finally, the characteristics of each control method and line loss are compared and analyzed.

• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.81-86
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• 2012

This paper presents a VLSI design for lifting-based discrete wavelet transform (DWT) 9/7 filter using multiplierless multiple constant multiplication (MCM) architecture. This proposed design is based on the lifting scheme using pattern search for folded architecture. Shift-add operation is adopted to optimize the multiplication process. The conventional serial operations of the lifting data flow can be optimized into parallel ones by employing paralleling and pipelining techniques. This optimized design has simple hardware architecture and requires less computation without performance degradation. Furthermore, hardware utilization reaches 100%, and the number of registers required is significantly reduced. To compare our work with previous methods, we implemented the architecture using Verilog HDL. We also executed simulation based on the logic synthesis using $0.18{\mu}m$ CMOS standard cells. The proposed architecture shows hardware reduction of up to 60.1% and 44.1% respectively at 200 MHz clock compared to previous works. This implementation results indicate that the proposed design performs efficiently in hardware cost, area, and power consumption.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.267-280
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• 2017

Objective: The aim of this study is to investigate key user experience factors of interactions for Head Mounted Display (HMD) devices in the Virtual Reality Environment (VRE). Background: Virtual reality interaction research has been conducted steadily, while interaction methods and virtual reality devices have improved. Recently, all of the virtual reality devices are head mounted display based ones. Also, HMD-based interaction types include Remote Controller, Head Tracking, and Hand Gesture. However, there is few study on usability evaluation of virtual reality. Especially, the usability of HMD-based virtual reality was not investigated. Therefore, it is necessary to study the usability of HMD-based virtual reality. Method: HMD-based VR devices released recently have only three interaction types, 'Remote Controller', 'Head Tracking', and 'Hand Gesture'. We search 113 types of research to check the user experience factors or evaluation scales by interaction type. Finally, the key user experience factors or relevant evaluation scales are summarized considering the frequency used in the studies. Results: There are various key user experience factors by each interaction type. First, Remote controller's key user experience factors are 'Ease of learning', 'Ease of use', 'Satisfaction', 'Effectiveness', and 'Efficiency'. Also, Head tracking's key user experience factors are 'Sickness', 'Immersion', 'Intuitiveness', 'Stress', 'Fatigue', and 'Ease of learning'. Finally, Hand gesture's key user experience factors are 'Ease of learning', 'Ease of use', 'Feedback', 'Consistent', 'Simple', 'Natural', 'Efficiency', 'Responsiveness', 'Usefulness', 'Intuitiveness', and 'Adaptability'. Conclusion: We identified key user experience factors for each interaction type through literature review. However, we did not consider objective measures because each study adopted different performance factors. Application: The results of this study can be used when evaluating HMD-based interactions in virtual reality in terms of usability.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.253-258
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• 2007

Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram- positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin-resistant enterococci (VRE), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.

• Biomedical Science Letters
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• v.20 no.2
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• pp.77-84
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• 2014

Periodic analysis of local epidemiologic data of prevalent pathogens of blood culture can provide clinicians with relevant information to guide empirical antibiotic therapy. In this study, we analyzed a pattern of change of causative microorganisms and antimicrobial resistance at a tertiary medical center in Chungcheong province from 2003 to 2012, retrospectively. Of 70,258 blood specimens cultured, 6,063 (8.6%) were positive. Among the positive isolates, 95.9% were aerobic or facultative anaerobic bacteria, 0.1% were anaerobes, and 3.9% were fungi. Coagulase-negative Staphylococci (CoNS) (32.9%), Escherichia coli (16.7%), Staphylococcus aureus (9.1%), Klebsiella pneumoniae (6.4%), and ${\alpha}$-hemolytic Streptococcus (5.9%) were commonly isolated bacteria, and Candida albicans (1.4%) was the most commonly isolated fungi. Enterococcus faecium progressively increased but Streptococcus pneumoniae, Acinetobacter baumannii and Proteus species gradually decreased over a period of 10 years. The multidrug-resistant microorganisms such as methicillin-resistant S. aureus (MRSA), vancomycin-resistant enterococci (VRE), cefotaxime-resistant E. coli, imipenem-resistant Pseudomonas aeruginosa (IRPA) and imipenem-resistant A. baumannii (IRAB), were significantly increased. Therefore, there is a need for a more strict control of antibiotics and a more updated guideline for the treatment of bloodstream infection.