• Journal of Life Science
• /
• v.22 no.4
• /
• pp.508-515
• /
• 2012

In this study, DEAE-cotton [derivatized by 2-(diethylamino)ethyl chloride hydrochloride (DEAE HCl)] was prepared as a carrier for immobilized $Pichia$ $stipitis$ for ethanol production. When cotton was derivatized with 0.5 M DEAE HCl, the yeast cell suspension was adsorbed at 100% of the initial cell $OD_{600}$. The adsorbed yeast cells were estimated to be 101.8 mg-dry cells/g-DEAE-cotton. In particular, when a flask culture using the immobilized yeast cells was conducted in a glucose and xylose-containing medium, the yeast cells on the DEAE-cotton gradually produced ethanol, according to glucose and xylose consumption; the ethanol yield was approximately 0.33 g-ethanol/g-monosaccharide. Because DEAE-cotton was successfully used as a carrier for ethanol production from a glucose and xylose-containing medium, we expect that this bioethanol production process may be used for the bioethanol production process from the hydrolysate of lignocellulosic biomass. All the results of DEAE-cotton were compared with those of DEAE-cellulose as a carrier for immobilization.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.5
• /
• pp.46-55
• /
• 2012

This study proposes an estimate method of willingness to pay(WTP) for real-time route guidance systems using contingent valuation method(CVM) under double bounded dichotomous choice question(DBDCQ) and analysis for impact factors of WTP estimation. This study assumed that provided real-time traffic information service is optimal route concepts dealing with traffic conditions on origin-destination. Analysis targets were classified into two groups as short distance path and middle distance path for estimating WTP for realtime route guidance system in a year using the survival analysis method and the regression model with personal information, actual condition and satisfaction of information usage and users' awareness and usage of facilities. As a result, mean WTP of realtime route guidance system is 4,034won/year in short distance path, and 4,884won/year in middle distance path. Therefore real-time route guidance system for longer distance path is recognized as more valuable than shorter distance path. Moreover, the necessity of information was required on a higher income group and higher WTP was estimated on owners of vehicle group and lower awareness of a route group.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.12
• /
• pp.1740-1746
• /
• 2016

In this study, we investigated the nutritional and functional constituents as well as quality characteristics and antioxidant activity of Korean cultivated wild ginseng (KG). The chemical compositions and amino acid content of KG were 7.56% water, 73.01% carbohydrates, 12.58% protein, 1.99% lipids, and 5.54% ash as well as 16.17 mg/g of amino acids, respectively. The major ginsenoside and minor ginsenoside contents of KG were 15.94 mg/g and 0.04 mg/g, respectively. The total polyphenol and flavonoid contents of KGE (Korean cultivated wild ginseng with 70% ethanol extract) were 8.93 mg GAE/g and 3.96 mg RHE/g, respectively. KGE also showed higher antioxidant activity than the other extracts (KGW, Korean cultivated wild ginseng with water extract) with regard to DPPH and ABTS radical scavenging activities (57.75% and 70.73%, respectively), nitrite oxide scavenging activity (44.01%), SOD-like activity (78.05%), reducing power activity ($1.08OD_{700nm}$), and ferrous ion-chelating activity (65.33%). Additionally, KGE had higher elastase, collagenase, and tyrosinase inhibition activities than KGW. These results suggest that KGE can be used as a bioactive and functional material in the food industry.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.11 no.1
• /
• pp.53-62
• /
• 1987

High power lasers provide a controllable and precise energy source in surface transformation hardening. A careful control of the process is needed in order that the surface layer of the material reaches the austenizing temperature, but that it does not melt. In order to achieve this the results of theoretical and experimental studies on the laser surface hardening of a medium carbon steel are described. A two-dimensional computer program, which can be used generally for the determination of transient temperature distributions in welding and heat treatment, was established on the basis of the finite element method. For the confirmation of the accuracy of the numerical analysis, a medium carbon steel (SM 45C) of 5mm thickness was heat-treated with a 1kW CW CO$_{2}$ laser machine, while the traverse speed and the distance from the focal point (defocused distance) were varied. Experimental and numerical results showed a similar tendency in correlations between the hardened zone shape and the process parameters. With increasing beam spot diameter the width and depth of the hardened zone increased for relatively small beam spot diameters, but decreased rapidly after reaching the maximum value, while with increasing traverse speed the width and depth of the hardened zone decreased monotonously. Too small beam spot diameters are to be avoided, since the surface melting would lower the surface hardness and produce an uneven surface which may be unacceptable because of the possible requirement for subsequent machining. It could be observed that for a given traverse speed and laser power input there exists a optimal range of the beam spot diameter, which produce a large width of the hardened zone but no melting on the surface.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.96-105
• /
• 2019

This study analyzed the correlation of work values, career attitude maturity and employment preparation behavior by determining the sociodemographic characteristics, and the study confirmed the validity of the influence of work values and career attitude maturity on employment preparation behavior. The subjects of this study were 218 nursing students at a university located in Geonggi-do. The data was collected from June 4th to August 27th, 2019 by using structured questionnaires. As a result, female students scored significantly higher in work values and career attitude maturity than did the male students, and the students who had better grades showed higher employment preparation behavior. In addition, the result showed positive correlation between work values and employment preparation behavior, and the study showed correlation between career attitude maturity and employment preparation behavior. Greater independence, readiness, certainty, and decisiveness were higher and were sub-factors of career attitude maturity and employment preparation behavior. Moreover, the higher the students' patriotism and indoor activities, the higher was their employment preparation behavior. In conclusion, the employment preparation behavior was higher according to greater work values, while the influence of career attitude maturity on employment preparation behavior was not statistically significant.

• Microbiology and Biotechnology Letters
• /
• v.44 no.3
• /
• pp.341-348
• /
• 2016

This study aimed to develop a microbial process for producing aminolevulinic acid (ALA) using crude glycerol. In the culture of ALA-producing cells (Escherichia coli/pH-hemA) in a medium containing crude glycerol, the cell density and production were 1.8-fold and 1.2-fold lower than those obtained from pure glycerol, respectively. However, the cell growth and production were improved by supplementing the medium with trehalose (30 or 100 g/l). Engineered cells (E. coli/pH-hemA/pS-otsBA) were constructed to express otsBA and their culture performance was compared with that of control cells (E. coli/pH-hemA/ pSTV28). The effects of isopropyl β-D-1-thiogalactopyranoside (IPTG) concentration and the time of induction were examined to improve the cell growth and ALA production in engineered cells cultured using crude glycerol. When 0.6 mM of IPTG was added at the beginning of the exponential growth phase, the ALA produced by cells was 2,121 mg/l, which was comparable to that from pure glycerol. The results demonstrate that otsBA expression endowed cells with the capacity to tolerate the toxicity of crude glycerol for direct use.

• Journal of Navigation and Port Research
• /
• v.30 no.6 s.112
• /
• pp.471-481
• /
• 2006

This paper aims to provide strategies to attract container cargoes for the Incheon port by analysing O/D of the container cargoes with the year-2004 export and import data from. The Korean customs service. O/D analysis was carried out with establishing optimal zones, which are defined as City, Gun, Gu(Korean administrative districts) to which the export-import service can be provided from a certain port with minimized freight(or transport) cost and stevedoring fee. For the Incheon port, 35 administrative districts including Seoul and Incheon in Kyunggi-Do and Kangwon-Do are recognized as the optimal zones, and approximately 25.50% of around 2.02-million-TEU per year of the cargoes from the zones are exported and imported through the port. The strategies to attract container cargoes was suggested by comparing the Incheon port to supposed-competitive ports. The Busan port(64.89%), Guangyang port(4.46%) and Pyeongtaeck port(3.35%) are supposed as the competitive ports which have a large proportion of handling the cargoes from the optimal zones. When comparing the Incheon port to these ports. The Incheon port requires a distinctive cost strategy, providing incentives to attract shipping companies and cargoes, improving efficiency related to loading-unloading at the port, and reinforcing Feeder-Network and advertisements about cost-saving to the shippers(the owners of goods) in the national capital region Consequently, the mentioned requirements are suggested as the strategies to attract cargoes for the Incheon port.

• Microbiology and Biotechnology Letters
• /
• v.48 no.3
• /
• pp.287-295
• /
• 2020

Lactobacillus zymae GU240 was previously isolated from Kimchi, a Korean fermented vegetable, as a strong GABA producer. The strain showed β-galactosidase (β-Gal) activity on MRS agar plates with X-gal. When growth and β-Gal activities of GU240 were measured using MRS (glucose, 2%, w/v) and MRSL (lactose, 2%, w/v) broths, cells were found to grow slowly in MRSL, and the β-Gal activity (36 units at 4 h) was lower than that of cells grown in MRS (94 units at 16 h). The highest OD₆₀₀ value of the culture in MRS was 1.6 at 24 h at 37℃, whereas that of the culture in MRSL was 0.6 at 16 h. β-Gal activity of the culture in MRS reached the maximum (95.6 u/ml) at 16 h, decreased thereafter, and was not detected at 48 h. β-Gal activity for culture in MRSL reached its highest (36 u/ml) at 4 h and decreased gradually, but some activity (11.05 u/ml) still remained at 72 h. The structural gene encoding β-Gal in L. zymae GU240 was cloned as a 3.1 kb fragment, and DNA sequencing confirmed the presence of complete lacLM genes. lacLM genes from L. zymae GU240 showed 98-99% homologies in nucleotide sequences with other lacLM genes from L. brevis. Reverse transcription (RT)-PCR confirmed the operon structure of lacLM. The results indicated that L. zymae GU240 might be in the process of losing the ability to grow rapidly on lactose-containing medium, such as milk, due to adaptations to plant environments, including kimchi.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.24 no.1
• /
• pp.121-141
• /
• 2011

Objective : This Experimental study was done to investigate the Effect of Taklisodok-um and Hwangryunhaedok-tang(TH) on Atopic Dermatitis. Methods : We assessed effects of TH on the IgE, IL-4, IL-5, IL-6, IgM, IgG1, IFN-${\gamma}$ in vivo, on the IL-4, IL-5, CCR3 in the skin tissues of ear and dorsum with NC/Nga mice. And we assessed effects of TH on the COX-2, IL-$1{\beta}$, TNF-${\alpha}$, IL-6 with RAW 264.7 cell. Results and Conclusion : 1. IgE, IL-4, IL-5, IL-6, IgM, IgGl levels in the serum of TH treated NC/Nga mouse group were decreased compared to the untreated control mice. IFN-r showed a increase in the experimental group compared to the untreated control group. The spleen weight of TH treated NC/Nga mice was decreased compared to the untreated control group. 2. mRNA expression levels of IL-4, IL-5 and CCR3 in the skin tissues of TH treated NC/Nga mice were decreased, and expression levels of IL-6 in the skin tissues of TH treated NC/Nga mice were decreased compared to the untreated control group. IFN-${\gamma}$ mRNA expression levels were increased compared to the untreated control group. 3. Judged from that IL-$1{\beta}$, TNF-${\alpha}$, IL-6 express of gene, effect of inflammatory Cytokines revelation were decreased compared to the untreated control group. 4. Depend on the strength of TH, inflammatory RAW 264.7 in the serum of TH were inhibited compared to the untreated control serum that leaded a COX-2 activity model. 5. Histological observation of the ear and skin tissues showed that the extents of inflammation and infiltrated immune cells in the epidermis and dermis of TH treated NC/Nga mice were highly reduced compared to the untreated control group.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.1
• /
• pp.429-433
• /
• 2013

Objectives: To explore the correlation between multi-slice spiral CT (MSCT) perfusion parameters and the expression of vascular endothelial growth factor (VEGF) as well as matrix metalloproteinase-2 (MMP-2) in breast cancer. Methods: Forty five breast cancer patients and 16 patients with benign breast tumor, both confirmed by pathology examination, were enrolled. All underwent MSCT perfusion imaging to obtain perfusion maps and data for parameters including blood flow (BF), blood volume (BV) and permeability surface (PS). Cancer patients did not receive treatment prior to surgery. The expression of VEGF and MMP-2 were examined with both immunohistochemistry and Western blotting. Results: The levels of VEGF and MMP-2 by immunohistochemistry were significantly higher in the breast cancer group (P < 0.01) than the benign tumor group. Relative OD values from Western blotting were also higher in cancer cases (P < 0.05). Similarly, the mean MSCT perfusion parameters (BF, BV, PS) were significantly higher in the breast cancer group (P < 0.01), BF and BV positively correlating with VEGF expression (r = 0.878 and 0.809 respectively, P < 0.01); PS and VEGF and MMP-2 expression were also positively correlated (r= 0.860, 0.786 respectively, P < 0.01). Conclusion: There is a correlation between breast cancer MSCT perfusion parameters and VEGF andMMP-2 expression, which might be useful for detection of breast lesions, qualitative diagnosis of breast cancer, and evaluation of breast cancer treatment.