• Elastomers and Composites
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• v.49 no.4
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• pp.293-304
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• 2014

Rubber air spring (RAS) is a special suspension device for the industries of automobile, railroad car and other transportation. A RAS serves as a spring component with the elastic effect of compression and expansion of air in a composite rubber bag. The main component of RAS is the rubber sleeve. Rubber sleeve is the composite which is made up of combination of chloroprene rubber (CR) and nylon 6 cord, and the adhesive strength between CR and nylon 6 cord is very important. In this study, considering the effects of additives in rubber sleeve, various physical properties were tested to find the optimal combination of composition and conditions. Further, in order to select the optimum orientation of the reinforcing fibers, numerical analysis was performed using the finite elements method. After assembling all components of RAS, it was mounted on an actual vehicle, and then it was tested air leakage, fatigue life and fundamental properties.

• Membrane Journal
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• v.31 no.6
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• pp.393-403
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• 2021

Enzymes are important class of catalyst for biotransformation. Stability and reusability of enzymes during the catalysis process is a key issue. Activity of enzyme can be enhanced by its immobilization on a suitable substrate by creation of specific microenvironment. A variety of membranes has been used as substrate due to the biocompatibility and simpler method to tune hydrophilicity/hydrophobicity property of the membrane surface. In this review, polymer membranes including cellulose, polyacrylonitrile (PAN), polydimethylsiloxane (PDMS), polyvinylidene fluoride (PVDF), polyethersulfone (PES) are introduced and discussed in detail. Biodegradation of organic contaminants by immobilized enzyme is an environmental friendly process to reduce the contamination of environment in pharmaceutical company and textile industries. The controlled hydrolysis of oil can be performed in enzyme immobilized membrane bioreactor (EMBR), resulting in reducing carbon emission and reduced environmental pollution. Bioethanol and biodiesel are considered alternative fossil fuels that can be prepared in EMBR.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.749-760
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• 2022

Omics-driven synthetic biology is a multidisciplinary research field that creates new artificial life by employing genetic components, biological devices, and engineering technique based on genetic knowledge and technological expertise. It is also utilized to make valuable biomaterials with limited production via current organisms faster, more efficient, and in huge quantities. As the bioeconomic age begins, and the global synthetic biology market becomes more competitive, investment in research and development (R&D) and associated sectors has grown considerably. By overcoming the constraints of present biotechnologies through the merging of big data and artificial intelligence technologies, huge ripple effects are envisaged in the pharmaceutical, chemical, and energy industries. In agriculture, synthetic biology is being used to solve current agricultural problems and develop sustainable agricultural systems by increasing crop productivity, implementing low-carbon agriculture, and developing plant-based, high-value-added bio-materials such as vaccines for diagnosing and preventing livestock diseases. As international regulatory debates on synthetic biology are now underway, discussions should also take place in our country for the growth of bioindustries and the dissemination of research findings. Furthermore, the system must be improved to facilitate practical application and to enhance the risk evaluation technology and management system.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.38-47
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• 2018

In this study, the antioxidant activities of hot water extracts of Rugosa rose (Rosa rugosa Thunb.) were evaluated. Total phenolic compounds (TPC) and total flavonoid compounds (TFC) were the highest in the leaf extracts at 107.29 mg/g and 24.28 mg/g, respectively. The DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging activity was in the following order: flower extract > leaf extract > seed extract > fruit extract. The $IC_{50}$ values for DPPH and ABTS of the flower extract were $0.87mg/m{\ell}$ and $0.27mg/m{\ell}$, respectively. The amount of gallic acid was higher in the flower (4.51 mg/g) and leaf extracts (0.97 mg/g) than in the other extracts. Among the fraction (A-F) of each extract, antioxidant activity was the highest in the C fraction of flower extract. It is due to high TPC (3305.43 mg/g) and TFC (878.42 mg/g). Statistical analysis revealed a strong correlation between TFC (or TPC) and radical scavenging activity at p-value < 0.001. Collectively, these results suggest that the hot water extracts of rugosa rose have potential antioxidant effects, and can be used in food, cosmetics, and the pharmaceutical industries.

• Journal of Life Science
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• v.19 no.8
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• pp.1003-1008
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• 2009

Abalone (genus Haliotis) is a woody species with a long life span that is primarily distributed throughout the world, including Asia. This species is regarded as a very important marine gastropod mollusk in Korea and China, and also in food industries around the world. We evaluated a representative sample of the five species with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within the genus. Aligned nucleotide sequences of the length of the 5.8S subunit of all taxa of Haliotis were found to constant of 160 bp nucleotides. However, aligned nucleotide sequences of the length of ITS1 were varied within genus Haliotis, varying from 272 in H. diversicolor aquatilis to 292 in H. discus hannai. Aligned nucleotide sequences of the length of ITS2, especially, vary from 722 in H. diversicolor aquatilis to 752 in H. sieboldii. Total alignment length is 763 positions, of which 78 are parsimony-informative, 57 variable but parsimony-uninformative, and 459 constant characters. H. discus hannai was similar to H. discus, while H. diversicolor aquatilis was more distinct. ITS analysis may be useful in germ-plasm classification several taxa of genus Haliotis.

• Journal of Life Science
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• v.28 no.1
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• pp.130-139
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• 2018

In ancient times, horse racing was done in ancient European countries in the form of wagon races or mountain races, and wagon racing was adopted as a regular event at the Greek Olympic Games. Thoroughbred horse has been bred since 17th century by intensive selective breeding for its speed, stamina, and racing ability. Then, in the 18th century, horse racing using the Thoroughbred species began to gain popularity among nobles. Since then, horse racing has developed into various forms in various countries and have developed into flat racing, steeplechasing, and harness racing. Thoroughbred racehorse has excellent racing abilities because of powerful selection breeding strategy for 300 years. It is necessary to maintain and maximize horses' ability to race, because horse industries produce enormous economic benefits through breeding, training, and horse racing. Next-generation sequencing (NGS) methods which process large amounts of genomic data have been developed recently. Based on the remarkable development of these genomic analytical techniques, it is now possible to easily carry out animal breeding strategies with superior traits. In order to select breeding racehorse with superior racing traits, the latest genomic analysis techniques have to be introduced. In this paper, we will review the current efforts to improve race performance for racehorses and to examine the research trends of genomic analysis. Finally, we suggest to utilize genomic analysis in Thoroughbred racehorse and Jeju horse, and propose a strategy for selective breeding for Jeju horse, which contributes job creation of Korea.

• Journal of Life Science
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• v.30 no.10
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• pp.919-929
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• 2020

Aromatic compounds are widely used in the chemical, food, polymer, cosmetic, and pharmaceutical industries and are produced by mainly chemical synthesis using benzene, toluene, and xylene or by plant extraction methods. Due to many rising threats, including the depletion of fossil fuels, global warming, the strengthening of international environmental regulations, and the excessive harvesting of plant resources, the microbial production of aromatic compounds using renewable biomass is regarded as a promising alternative. By integrating metabolic engineering with synthetic and systems biology, artificial biosynthetic pathways have been reconstituted from L-tryptophan biosynthetic pathway in relevant microorganisms, such as Escherichia coli and Corynebacterium glutamicum, enabling the production of a variety of value-added aromatic compounds, such as 5-hydroxytryptophan, serotonin, melatonin, 7-chloro-L-tryptophan, 7-bromo-L-tryptophan, indigo, indirubin, indole-3-acetic acid, violacein, and dexoyviolacein. In this review, we summarize the characteristics, usage, and biosynthetic pathways of these aromatic compounds and highlight the latest metabolic engineering strategies for the microbial production of aromatic compounds and suitable solution strategies to overcome problems in increasing production titers. It is expected that strain development based on systems metabolic engineering and the optimization of media and bioprocesses using renewable biomass will enable the development of commercially viable technologies for the microbial production of many aromatic compounds.

• Journal of Life Science
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• v.28 no.12
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• pp.1545-1553
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• 2018

The International Society of Rare Sugars (ISRS) defines rare sugars as monosaccharides and their derivatives that rarely occur in nature. Rare sugars have recently received much attention because of their many uses including low-calorie sweeteners, bulking agents, and antioxidants, and their various applications including as immunosuppressants in allogeneic rat liver transplantation, as potential inhibitors of various glycosidases and microbial growth, in ischemia-reperfusion injury repair in the rat liver, and in segmented neutrophil production without detrimental clinical effects. Because they rarely exist in nature, the production of rare sugars has been regarded as one of the most important research areas and, generally, they are produced by chemical synthesis. However, the production of rare sugars by bioconversion using enzymes from microorganisms has been receiving increased attention as an environmentally friendly alternative production method. In particular, D-allulose, D-allose, and D-tagatose are of interest as low-calorie sweeteners in various industries. To date, D-tagatose 3-epimerase, D-psicose 3-epimerase, and D-allulose 3-epimerase have been reported as D-allulose bioconversion enzymes, and L-rhamnose isomerase, Galactose 6-phosphate isomerase, and Ribose 5-phosphate isomerase have been identified as D-allose production enzymes. Elsewhere, D-tagatose has been produced by L-arabinose isomerase from various microorganisms. In this study, we report the production of D-allulose, D-allose, and D-tagatose by microorganism enzymes.

• Journal of Life Science
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• v.29 no.10
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• pp.1071-1079
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• 2019

In this study, we investigated the antioxidant and anti-aging activities of Schisandra chinensis seed fractions by adding them to UVB-irradiated HaCaT cells and analyzing the suppression of matrix metalloproteinases (MMPs). An electron-donating assay, ABTS radical scavenging assay, and hydrogen peroxide scavenging assay showed that the ethyl acetate fraction of S. chinensis seed (SCEAf) has scavenging activities. A collagenase inhibition activity assay showed that SCEAf had inhibitory effects of over 92.3% at $500{\mu}g/ml$ concentration. An MTT assay was performed to determine the cytotoxicity of SCEAf in HaCaT cells and the results showed that SCEAf increased cellular viability in a concentration-dependent manner. In addition, SCEAf was found to increase the viability of cells irradiatged by UVB $50mJ/cm^2$. To examine the anti-aging effects of SCEAf on HaCaT cells irradiated with UVB $50mJ/cm^2$, the expression of MMP-1 and -3 was analyzed by Western blotting and reverse-transcription polymerase chain reaction. The results showed that MMP-1 and -3 proteins and mRNA levels were downregulated in a concentration-dependent manner in response to SCEAf. These results suggest that SCEAf can prevent aging and alleviate aging symptoms by inhibiting collagenase activity in skin keratinocytes damaged by UVB. Therefore, S. chinensis seeds may have the potential for use as functional ingredients with anti-aging effects in the cosmetic and food industries.

• Journal of Life Science
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• v.29 no.5
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• pp.524-529
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• 2019

Medicinal plants resources are becoming important assets since their usages have been expanded to the development of functional foods for human health, cosmetics and pharmaceutical industries. However, their phylogenetic origins and names are different from each country and quite often they are mixed each other resulting in the confusion for consumers. Particularly when they are very similar based on their morphological characteristics and distributed, it is extremely difficult to differentiate their origins even by specialists. Therefore, identification of each plant species is important for standardizing herbal medicine. Thistle is a medicinal and perennial plant. Obtaining information about the genetic diversity of plant populations is highly important for conservation and germplasm utilization. Although thistle is an important medicinal plant species registered in South Korea, no molecular markers are currently available to distinguish from other similar species from different countries. In this study, we developed single nucleotide polymorphism (SNP) markers derived from chloroplast genomic sequences to identify distinct Korean-specific thistle species via high resolution melting (HRM) curve analyses. We performed molecular authentication of four different kinds of thistle species from different regions using DNA sequences in the trnL-F and matK chloroplast intergenic region. The SNP markers developed in this study are useful for rapidly identifying specific thistle species from different country.