• Food Engineering Progress
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• v.13 no.1
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• pp.44-49
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• 2009

Angelicae gigantis Radix (dried root of Angelica gigas) including major bioactives such as decursin and decursinol angelate provides rich flavors and several healthy benefits. Recent studies have shown that ultrafine powders of herbal medicines provide better physical properties and biological activities. Thus, ultrafine Angelica powder was added into the oligosaccharide syrup to provide flavors and healthy benefits in this study. Angelicae gigantis Radix was pulverized into d(0.1) = 3.220, d(0.5) = 7.822, and d(0.9) = 7.817 $\mu$m respectively using an air-flow mill. The ultrafine Angelica powder was added into the oligosaccharide syrup process with different ratios of water to oligosaccharide syrup at 1:5, 1:8, 1:11, and 1:14. The physicochemical properties such as viscosity and bulk density were measured. The Stokes' law was applied to predict the sedimentation velocity of the added Angelica powder in the syrup. The Angelica syrup prepared in this experiment showed good stability since the Angelica particles precipitated down slowly. The ratio of water to oligosaccharide syrup at 1:11 showed the optimal preparation in terms of the stability and the viscosity. The ultrafine-sized herbal powders such as Angelicae gigantis Radix have potentials for various food and pharmaceutical applications.

• Advances in nano research
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• v.10 no.4
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• pp.359-371
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• 2021

A tumor immune interaction is a main topic of interest in the last couple of decades because majority of human population suffered by tumor, formed by the abnormal growth of cells and is continuously interacted with the immune system. Because of its wide range of applications, many researchers have modeled this tumor immune interaction in the form of ordinary, delay and fractional order differential equations as the majority of biological models have a long range temporal memory. So in the present work, tumor immune interaction in fractional form provides an excellent tool for the description of memory and hereditary properties of inter and intra cells. So the interaction between effector-cells, tumor cells and interleukin-2 (IL-2) are modeled by using the definition of Caputo fractional order derivative that provides the system with long-time memory and gives extra degree of freedom. Moreover, in order to achieve more efficient computational results of fractional-order system, a discretization process is performed to obtain its discrete counterpart. Furthermore, existence and local stability of fixed points are investigated for discrete model. Moreover, it is proved that two types of bifurcations such as Neimark-Sacker and flip bifurcations are studied. Finally, numerical examples are presented to support our analytical results.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.137-150
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• 2021

The rock-carved standing Buddha triad in Seoak-dong is a large stone Buddha statue of the Unified Silla era (AD 676 to 935) in ancient Korea, built near the top of the southeastern side of mountain Seondosan in Gyeongju, is characterized by its locational importance, the powerful Amitabha and the gentle sculptural technique of the Bodhisattva. In particular, Amitabha Buddha in andesite rock slope with biotite granite pedestal and two Bodhisattva parallel made by alkali granites seems to express the dignity through the color and texture of the stones. In the Amitabha Buddha, deterioration characteristics are accelerating due to the combination of various joint systems, instability of the slopes and relaxation by the root pressure of plants occurring at the top. In addition, physical properties have deteriorated owing to the increase of discontinuous surfaces as joints, cracks and scalings, and the coverage of algae and lichen is also high. Therefore, deterioration degree in Buddha triad is accelerated due to the physical weathering characteristics from natural rock mass and various biological invasion.

• Animal cells and systems
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• v.8 no.3
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• pp.213-220
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• 2004

MicroRNA and siRNA (small interfering RNA), representative members of small RNA, exert their effects on target gene expression through association with protein complexes called miRNP (microRNA associated ribonucleoproteins) and RISC (RNA induced silencing complex), respectively. Although the protein complexes are yet to be fully characterized, human EIF2C2 protein has been identified as a component of both miRNP and RISC. In this report, we raised antiserum against EIF2C2 in order to begin understanding the protein complexes. An immunoblot result indicates that EIF2C2 protein is ubiquitously expressed in a variety of cell lines from human and mouse. EIF2C2 protein exists in both cellular compartments, as indicated by an immunoblot assay with a nuclear extract and a cytosolic fraction (S100 fraction) from HeLa S3 lysate. Depletion of EIF2C1 or EIF2C2 protein resulted in a decrease of microRNA, suggesting a possible role of these proteins in microRNA stability or biogenesis. We also prepared antiserum against dsRNA binding protein PACT, whose homologs in C. elegans and Drosophila are known to have a role in the RNAi (RNA interference) pathway. The expression of PACT protein was also observed in a wide range of cell lines.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.662-671
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• 2015

To enrich the genetic resource of microbial xylanases with high activity and stability under alkaline conditions, a xylanase gene (xynSL4) was cloned from Planococcus sp. SL4, an alkaline xylanase-producing strain isolated from the sediment of soda lake Dabusu. Deduced XynSL4 consists of a putative signal peptide of 29 residues and a catalytic domain (30-380 residues) of glycosyl hydrolase family 10, and shares the highest identity of 77% with a hypothetical protein from Planomicrobium glaciei CHR43. Phylogenetic analysis indicated that deduced XynSL4 is closely related with thermophilic and alkaline xylanases from Geobacillus and Bacillus species. The gene xynSL4 was expressed heterologously in Escherichia coli and the recombinant enzyme showed some superior properties. Purified recombinant XynSL4 (rXynSL4) was highly active and stable over the neutral and alkaline pH range from 6 to 11, with maximum activity at pH 7 and more than 60% activity at pH 11. It had an apparent temperature optimum of 70℃ and retained stable at this temperature in the presence of substrate. rXynSL4 was highly halotolerant, retaining more than 55% activity with 0.25-3.0 M NaCl and was stable at the concentration of NaCl up to 4M. The enzyme activity was significantly enhanced by β-mercaptoethanol and Ca²⁺ but strongly inhibited by heavy-metal ions and SDS. This thermophilic and alkaline- and salt-tolerant enzyme has great potential for basic research and industrial applications.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.320-323
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• 2003

The effects of pH on the binding of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) expressed from transgenic plant cell suspensions to cationic and anionic exchange resins were investigated. In terms of stability, the optimum pH was found to be 5-7. In the case of using buffer exchange, when CM-sepharose was used as a cationic exchange resin, the best binding pH was 4.8 (77%) and when DEAE-sepharose was used as an anionic exchange resin, the best binding pH was 5.5 (74%). Without using buffer exchange, the optimum pH was 4.6 and the adsorption yield was 84%. From these results, a possibility of overcoming the degradation and instability of secreted protein product by in firm adsorption was found.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.47-52
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• 2015

To improve both the GOD immobilization capability and sensitivity of MWCNTs-based biosensor electrode, the electrode was prepared by adding different quantities of GO. The addition of GO increased hydrophilicity and the surface free energy of electrodes for glucose sensing as well as the dispersion of MWCNTs. In addition, the GOD immobilization capability was enhanced and the sensitivity was improved up to $121{\mu}A\;mM^{-1}$ even though having a high $K_m$ value (0.105) when adding 0.05 g GO to 0.05 g MWCNTs. These experimental results were attributed to the fact that the improvement in dispersion stability for MWCNTs, hydrophilicity, and surface free energy of electrode surface due to the addition of GO affected GOD immobilization capability.

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.399-405
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• 1999

Intergeneric hybrids between Saccharomyccopsis fiburigera KCTC 7393 and Saccharomyces cerevisiae KCTC 7049 (tyr-, ura-) were obtained by nuclear transfer technique. Nuclei isolated from the wild type S. fiburigera strain were transfered into auxotrophic S. cerevisiae mutants and new strains showing an increased starch degrading capability were selected. Maximum production of protoplasts was obtained from the treatment with 0.1 % Novozym 234 at $30^{\circ}C$ for 90 min, and most effective osmotic stabilizer for the isolation of protoplasts was 0.6 M KCl at pH 5.8. The frequency of protoplast regeneration was 14.64% under the conditions. Genectic stability, conidial size, DNA content, and nuclear stain suggested that the fusants were aneuploidy. The specific activity of ${\alpha}-amylase$ was observed to increase about $1.2{\sim}1.9$ folds.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1551-1559
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• 2013

This study was conducted to compare benthic macroinvertebrate communities of urban stream and nature stream in Daegu-si, Gyeongju-si, Gyeongsan-si, Andong-si, and Cheongsong-gun. The survey was carried out with 12 points in total six points for urban stream, six points for nature stream from Sept. 2011 to July 2012. In the urban stream were 33 species belonged to 24 families, 11 orders, 7 classes and 4 phyla while in the nature stream were 73 species belonged to 38 families, 12 orders, 5 classes and 4 phyla. In general, species diversity indices and species richness indices appeared low in urban stream but dominance indices was high. Functional feeding groups and Habitat Oriented Groups appeared comparatively simple in urban stream rather than nature stream. As a result of analysis of community stability, species included to area I and area III equally appeared in nature stream while species included to area I mostly appeared in urban stream. An analysis of the correlation between the population density and the number of species, the population number and biological indicators such as DI, H', RI, and ESB revealed that there was a significant correlativity with the diversity index and a very high correlativity with the number of species, abundance index and the ESB. On the other hand, the population number and the dominance index did not reveal any correlativity. For indicator species, Hydroptila KUa, Physa acuta appeared in urban stream while Paraleptophlebia chocolata, Epeorus pellucidus appeared in nature stream.

• KSBB Journal
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• v.30 no.3
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• pp.103-108
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• 2015

Production of foreign proteins by transgenic plant cell cultures has several advantages such as post-translational modification, low risk of product contamination and low-cost production and purification. However, target proteins are degraded by extracellular proteases existing in the media. A solution to this problem is the use of perfusion culture and ion exchange chromatography for the application of integrated bioprocess using in situ recovery. With this method, production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was investigated in this study. First, optimization of cell concentration during the induction phase for the production of hGM-CSF was examined. As cell concentration increased, the level of hGM-CSF was decreased due to the presence of extracellular proteases. Induction using sugarfree media produced 33% more hGM-CSF. The effects of pH on the binding of hGM-CSF to cationic and anionic exchange resins were also investigated. In terms of stability, optimal pH was found to be 5~7. In the case of using buffer exchange when CM-Sepharose was used as a cationic exchange resin, optimal pH for binding was 4.8 and adsorption yield was 77%. When DEAE-Sepharose was used as an anionic exchange resin, it was 5.5 (74%). Without buffer exchange, optimal pH was 4.6 (84%). From these results, an integrated bioprocess using in situ recovery with simultaneous production and separation of foreign protein in transgenic plant cell suspension cultures was found to be feasible.