• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.305-310
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• 1986

To improve the starch fermentation ability of yeast, hybrids were introduced by protoplast fusion of S. cerevisiae and S. diastaticus. The protoplasts of parental auxotrophic cells were fused in the presence of 10 mM CaCl$_2$and 30% of polyethyleneglycol (M.W 4, 000). The frequencies of fusant formation varied depending upon the strains used and were 3.51$\times$10$^{-4}$ to 5.04$\times$10$^{-4}$ for the regenerated protoplasts. The strains capable of extensive starch hydrolysis produce only 10% to total fusants. The 4 strains were finally selected by the results of starch fermentation and genetic stability test. The DNA content and cell volume of the fusants were greater than those of the parental strains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.885-891
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• 1996

Various problems in fermented fish products have been a major obstacle to manufacture the product in large scale, which is mainly concerned with the food safety. In this review, salt-fermented anchovy was selected to elucidate the characteristics of microorganisms involved in fermentation; thereby, it is suggested for research areas to achieve the quality improvement of tile product. Different microorganisms were involved in fermentation of anchovy. Dominant species were reported to be Bacillus sp., Pseudomonas sp., and Micrococcus sp., other microorganisms were Vibro sp., Clostridim sp., Serratia sp., Achromobacter sp., Streptococcus sp., Breuibacterium sp., Halobacterium sp., Flavobacterium sp., Corynebacterium sp., Acinetobacter sp., Sarcina sp., Staphylococcus sp., Torulopsis sp., and Saccharomyces sp. To standardize the quality of fermented fish products, screening and isolation of promising microorganisms should be carried out to develop different types of products; at the same time, proper sanitation control should be employed to keep the commercial value of the product by prolonging the shelf life.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.70-77
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• 2008

Conventional PDP power system, which commonly uses two isolation transformer, consists of sustaining power ($V_S$), addressing power($V_A$), and Multi power($V_M$). Because each of these power conversion circuits use transformer and control IC, there are several defects: decrease of efficiency, rise of cost, and parts stress. This paper is proposed the method which operates PDP power system only with one transformer. The proposed method contributes not only to high-efficient performance of the DC/DC power stage and improvement of reliability but also to reduction of cost by reducing volume and size. Also, proposed method is proper to Address Display-period Separation(ADS) which is one of the driving methods of PDP. Superiority of the proposed method is proved by comparison with conventional method and theoretical, experimental analysis.

• Journal of People, Plants, and Environment
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• v.21 no.6
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• pp.557-564
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• 2018

Along with the aging society, the prevalence of dementia is also increasing. Dementia causes short-term memory loss as well as difficulties of performing daily activities and gradually causes suffering of the patients and their family. In spite of various programs for prevention of dementia of older people are being implemented, there is a lack of developing natural-based program for physical and mental health promotion. Therefore, it is necessary to develop programs for the elderly living alone who are more vulnerable to dementia because of their social and economic isolation. The purpose of this study was to develop a natural-based program and investigate the effects of 10 weeks forest therapy program for dementia prevention to improve the psychological and physical health of the elderly living alone. The experimental subjects were 30 elderly (aged 65 or older) and 31 elderly participated in control group. The Stress response, depressive symptoms, weight, body mass index (BMI), fat mass and muscle mass were measured for pre and post test. The results showed that the experimental group showed subjective stress relief (t=5.249, p=.000), improvement in symptoms of depression (t=4.152, p=.000), and decreases in weight (t=2.686, p=.012), BMI (t=2.629, p=.014) and fat mass (t=2.918, p=.007) after the forest therapy program. The experimental group showed lower stress reactions(t=-7.185, p=.000) and less depressive symptoms (t=-5.303, p=.000) than control group after participating the program. These results suggest that periodic forest exposure can help having less stressful and depressive status than non-forest exposure and the forest therapy program can reduce participants' psychological and physical risk factors of dementia.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.381-389
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• 2019

Chlorella vulgaris was isolated from the Nile River, Qalubia Governorate, Egypt, for possible use in biodiesel production. BG-II nutrient growth media was used for isolation and laboratory growth. Identification was performed via 18S rRNA gene amplification, followed by sequencing. The alga was exposed to UV-C (254 nm) for 15, 30, and 45 s to improve dry weight accumulation and to increase the oil production. Daily measurements of dry weight ($g{\cdot}l^{-1}$) were performed; oil content and volumetric lipid productivity were also determined. UV-C exposure led to an increase in the volumetric lipid productivity by 27, 27.3, and $32.4mg{\cdot}l^{-1}{\cdot}d^{-1}$ with 15, 30, and 45 s, respectively, as compared with the control, which resulted in $18mg{\cdot}l^{-1}{\cdot}d^{-1}$. Of the examined mutants, the one with the highest productivity was re-irradiated by UV-C (254 nm) for 15, 30, 45, and 60 s. For 15 s of exposure time, the oil content increased to 34%, while it was 31% at 30 s; further, it decreased to 22% at 45 and 60 s exposures. The fatty acid methyl ester profile was 82.22% in the first mutant at 45 s, compared with the wild strain that contained a total of 66.01% of FAs. Furthermore, the highest levels of polyunsaturated fatty acid methyl ester were observed in the mutant exposed for 45 s, and it reached 11.41%, which reduced the cetane number to 71.3.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.22-38
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• 2022

Recently, due to the temporary closure and isolation of facilities for developmental disabilities due to the prolonged COVID-19, the pain suffered by consumers is getting worse, and there is no clear solution due to the lack of information on inpatient services. Therefore, there is a need for a service system that can prevent institutional and psychological problems for consumers. The purpose of this study is to provide systematic inpatient treatment guides, post-discharge management, and correct education for children with developmental disabilities and their guardians. After deriving the needs and improvement factors of consumers through domestic service case analysis, we conducted co-creation with end-users using the double diamond methodology. A possible service concept was derived. Accordingly, a collaborative sharing app service was proposed, and the usefulness of the service was confirmed through the usability evaluation and verification of various stakeholders. It is expected that the results of this study will be utilized in the development of an assistance system for the developmental disability ward based on user experience.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.298-308
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• 2020

Genetic diversity among Thaumatococcus daniellii populations in the southwestern region of Nigeria were assessed using morphometric and molecular markers to determine the population structure and existing genetic relationship for its improvement, conservation and sustainable utilisation. Populations from five locations in each of the six states were used for the study. Morphometric data were collected on folia characters and analysed for variability. Genome DNA was isolated from the plant leaf and amplified by polymerase chain reaction with inter-simple sequence repeat markers (ISSR) to determine the allelic polymorphism, marker effectiveness and genetic relationship of the population. The results showed significant variations in petiole length and leaf dimensions of the populations within and across the states. These morphometric traits are the major parameters that delimit the populations and they correlated significantly at P≤0.05. Analysis of the electrophoregram showed that the ISSR markers are effective for the diversity study. A total of 136 loci were amplified with an average of 7.16 loci per marker, 63.2% of the loci were polymorphic. The Principal Coordinate Analysis revealed that seven factors accounted for 81.6% of the variation and the dendrogram separated the populations into two major groups at a genetic distance of 10 (about 90% similarity) with sub-groups and clusters. Most populations within the state had a high degree of similarity, nonetheless, strong genetic relationship exists among populations from different states. The close relationship between populations across the states suggests a common progenitor, which are likely separated by ecological or geographical isolation mechanisms.

• Journal of Space Technology and Applications
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• v.2 no.3
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• pp.187-194
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• 2022

Although the magnitude of the disturbance caused by the driving of the motor operated to secure the high-speed and precise directivity of the antenna is small, it acts as a major cause of impairing the image quality of the observation satellite, which requires precision directing performance. In order to acquire high-resolution image information through the improvement of the high-resolution observation satellite, proper vibration isolation and reduction design are required so that jitter generated when the directional antenna motor is driven is not transmitted to the main mission equipment. In this paper, the development process of the directional antenna vibration reduction device applied to real satellites and the effect of micro vibration reduction before and after application will be examined. This device was designed as a way to significantly improve the jitter problem by replacing only one gear in the directional antenna driving unit with a spring damper gear without any additional interface equipment. It was first applied and launched to a high-resolution earth observation satellite, and has been successfully operated so far.

• Animal Bioscience
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• v.36 no.8
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• pp.1209-1220
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• 2023

Objective: The use of probiotics as an alternative to antibiotics in animal feed has received considerable attention in recent decades. Lactic acid bacteria (LAB) have remarkable functional properties promoting host health and are major microorganisms for probiotic purposes. The aim of this study was to characterize LAB strains of the chicken digestive tract and to determine their functional properties for further use as potential probiotics in poultry. Methods: A total of 2,000 colonies were isolated from the ileum and cecal contents of the chickens based on their phenotypic profiles and followed by a preliminary detection for acid and bile tolerance. The selected 200 LAB isolates with exhibited well-tolerance in acid and bile conditions were then identified by sequencing the 16S rDNA gene, followed by acid and bile tolerance, antimicrobial activity, adhesion to epithelial cells and additional characteristics on the removal of cholesterol. Then, the two probiotic strains (L. ingluviei and L. salivarious) which showed the greatest advantage in vitro testing were selected to assess their efficacy in broiler chickens. Results: It was found that 200 LAB isolates that complied with all measurement criteria belonged to five strains, including L. acidophilus (63 colonies), L. ingluviei (2 colonies), L. reuteri (58 colonies), L. salivarius (72 colonies), and L. saerimneri (5 colonies). We found that the L. ingluviei and L. salivarius can increase the population of LAB and Bifidobacterium spp. while reducing Enterobacteria spp. and Escherichia coli in the cecal content of chickens. Additionally, increased concentrations of valeric acid and short chain fatty acids were also observed. Conclusion: This study indicates that all five Lactobacillus strains isolated from gut contents of chickens are safe and possess probiotic properties, especially L. ingluviei and L. salivarius. Future studies should evaluate the potential for growth improvement in broilers.

• Journal of Sensor Science and Technology
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• v.31 no.3
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• pp.175-179
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• 2022

The physical properties of biomaterials are important for their isolation and separation from body fluids. In particular, the precise evaluation of the multi-physical properties of single biomolecules is essential in that the correlation between physical and biological properties of specific biomolecule. However, the majority of scientific equipment, can only determine specific-physical properties of single nanoparticles, making the evaluation of the multi-physical properties difficult. The improvement of analytical techniques for the evaluation of multi-physical properties is therefore required in various research fields. In this study, we developed a motion-tracking algorithm to evaluate the multi-physical properties of single-nanoparticles by analyzing their behavior. We observed the Brownian motion and electric-field-induced drift of fluorescent nanoparticles injected in a microfluidic chip with two electrodes using confocal microscopy. The proposed algorithm is able to determine the size of the nanoparticles by i) removing the background noise from images, ii) tracking the motion of nanoparticles using the circular-Hough transform, iii) extracting the mean squared displacement (MSD) of the tracked nanoparticles, and iv) applying the MSD to the Stokes-Einstein equation. We compared the evaluated size of the nanoparticles with the size measured by SEM. We also determined the zeta-potential and surface-charge density of the nanoparticles using the extracted electrophoretic velocity and the Helmholtz-Smoluchowski equation. The proposed motion-tracking algorithm could be employed in various fields related to biomaterial analysis, such as exosome analysis.