• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.1
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• pp.1-14
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• 2009

Purpose: Oxidative stress was thought to play a critical role in neurodegenerative disease. Many in vivo and in vitro reports explained the possible pathway of human aging. But in therapeutic aspects, there was no clear answers to prevent aging associated with neural diseases. In this study, we investigated the antioxidant and neuroprotective effects of the Insamyangyung-tang (IYT). Methods: To estimate the antioxidant effects, we carried out 1.1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azinobis-(3- ethylbenzothiazoline-6- sulfonic acid (ABTS) radical cation decolorization assay, and measurement of total polyphenolic content. To evaluate neuroprotective effect of IYT in vitro. We performed thiazolyl blue tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) creation in SH-SY5Y. Tyrosine hydroxylase (TH) immunocytochemistry, nitric oxide (NO) assay, and TNF-${\alpha}$ assay in primary rat mesencephalic dopaminergic neurons. Results: The $IC_{50}$ values were $571.6{\mu}g/m{\ell}$ and $202.3{\mu}g/m{\ell}$ in DPPH and ABTS assay respectively. Total polyphenolic content was 1.05%. In SH-SY5Y culture, IYT significantly increased the decreased cell viability by 6-OHDA at the concentrations of $10{\mu}g/m{\ell}$ in pre-treatment group, $10-100{\mu}g/m{\ell}$ in post-treatment group, and $100{\mu}g/m{\ell}$ in co-treatment group. The production of ROS induced by 6-OHDA was significantly inhibited in IYT treated group. In mesencephalic dopaminergic cell culture, the IYT group reduced the dopaminergic cell loss against 6-OHDA toxicity and the production of No and TNF-${\alpha}$ at the concentration of $0.2{\mu}g/m{\ell}$. Conclusion: These results showed that IYT has antioxidant and neuroprotectctive effects in the dopaminergic cells through decreasing the production of ROS, NO and TNF-${\alpha}$ which can cause many neurodegenerative changes in brain cell.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.90-96
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• 2019

Natural gas has been regarded as one of major alternative fuels, because of the increment of mining shale gas and supplying PNG(Pipeline Natural Gas) from Russia. Thus, it needs to broaden the usage of natural gas as the increasing its supplement. In this situation, application of natural gas on the transport area is a good suggestion to reduce exhaust emissions such as CO₂(carbon dioxides) and soot from vehicles. For this reason, natural gas can be applied to SI(spark ignition) engines due to its anti-knocking and low auto-ignitibility characteristics. Recently, since turbocharged SI engine has been widely used, it needs to apply natural gas on the turbocharged SI engine. However, there is a major challenge for using natural gas on turbocharged SI engine, because it is hard to make natural gas direct injection in the cylinder, while gasoline is possible. As a result, there is a loss of fresh air when natural gas is injected by MPI (multi-point injection) method under the same intake pressure with gasoline-fueled condition. It brings the power reduction. Therefore, in this research, intake pressure was increased by controling the turbocharger system under natural gas-fueled condition to improve power output. The goal of improved power is the same level with that of gasoline-fueled condition under the maximum torque condition of each engine speed. As a result, the maximum power levels, which are the same with those of gasoline-fueled conditions, with improved brake thermal efficiency could be achieved for each engine speed (from 2,000 to 6,000 rpm) by increasing intake pressure 5-27 % compared to those of gasoline-fueled conditions.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.52-60
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• 2018

This study compares the differences of the fit factor by the order of wearing preference between Particulate filtering facepiece respirators(PFFR) and glasses when participants wore simultaneously and a survey of physical and visual complaint. Recognition level about fit of respirators was investigated and the educational (before- and after-) effect of the fit factor. When participants wore PFFR and glasses, physical complaints were nose pressure, slipping, nose and ear pressure, ear pressure and rim loosen, the most highly physical complaints were nose pressure. Visual complaints were demister, blurry vision, dizziness, visual field, and lens dirty, the most highly visual complaints were demister. But, there was significant difference in physical complaint such as nose pressure(10.3%), slipping (23.0%), nose and ear pressure(14.3%), and rim loosen(16.2%), visual complaint such as visual field(13.8%) and lens dirty(32.4%). For the recognition of fit of respirators, respirators fitness, leak site, an initial point and an object, faulty factor, recognition level was higher. Fit factor was increased after education of proper wearing of respirator. Change of the fit factor was smaller compared to the normal breathing and after 6 actions in case of after education. Questionnaire consisted of general characteristics and physical/visual complaint, recognition of fit. Complaints were measured after the QNFT with multiple choices. Quantitative fit factor was measured by device and compared the result of (before- and after-) educational effect. Also, we selected to 6 actions (Normal breathing, Deep breathing, Bending over, Turning head side to side, Moving head up and down, Normal breathing) among 8 actions OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The fit factor was higher after the training (p=0.000). Descriptive statistics, paired t-test, and Wilcoxon analysis were performed to describe the result of questionnaire and fit test. (P=0.05) Therefore, it is necessary to investigate the quantitative research such as training program and glasses fitting factor about the wearing of PFFR and glasses simultaneously.

• Microbiology and Biotechnology Letters
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• v.5 no.4
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• pp.177-184
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• 1977

Arylsulfatase catalyzes the release of SO$\sub$4//sup2/- from sulfate esters of simple phenols. Arylsolfatase occurs widely in animal tissues and in microorganisms including soil bacteria. Its widespread distribution suggests that it has a rather fundamental function and environmental meaning. It has been shown previously that arylsulfatase of Klebsiella was purified and characterized. A condition of arylsulfatase synthesis was tested with several strains of Serratia. Serratia marcescens could not utilize some sugars, such as xylose, rhamnose, glucosamine and arabinose hut glucose and mannitol as a sole carbon source. However, arylsulfatase synthesis was repressed by glucose but not by mannitol. The enzyme synthesis was repressed ob inorganic sulfate and methionine, and this repression was relieved by addition of tyramine. Arylsulfatase of S. marcescen was purified by fractionation with ammonium sulfate and followed by chromatographies on DEAE-Cellulose CM-Cellulose, and DEAE-Sephadex A-25. The molecular weight of arylsulfatase was determined to be 46,000 by SDS-Gel electrophoresis and 49,000 by Sephadex G-100 column chromatography. The enzyme showed some different properties with that of K. aerogenes. The activity was maximum at pH 6.8. The Km and Vmax values for p-nitrophenyl sulfate were 2.5${\times}$10$\^$－4/ M and 20 nmoles/min/mg protein, respectively. The enzyme showed high activities toward phenyl sulfate, ο-and p-nitro phenyl sulfates, and p-nitrocatechol sulfate. The inhibition of enzyme was strongly affected by hydroxylamine, inorganic fluoride, sulfide and phosphate, but by inorganic sulfate. Like Klebsiella arylsulfatase, tyramine, octopamine, and dopamine gave signifcant inhibitory effect.

• Journal of Distribution Science
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• v.12 no.11
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• pp.101-111
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• 2014

Purpose - This study aims to verify the construct of the service quality suitable to the characteristics of the business center, to develop the scale that can measure the service quality objectively, compare the diverse business centers in Korea, and present desirable methods of business center management and operation. Research design, data, and methodology - In the first stage, literature research and focus group interviews with current users and actual business experts of business centers were conducted. In addition, 69 early stage scale items were derived. In the second stage, a Delphi survey was conducted on the experts of business and academic circles. The measurement items in the early stage were supplemented and revised. The content validity rate (CVR) of 69 measures was computed and then the experts' opinions were used. As a result, the business center service quality scale, made up of 9 organizing factors and 36 measurement items, was constructed. In the third stage, a survey was conducted on the occupants who were currently using the business center. It was to confirm if the developed business center service quality scale could be actually utilized. The data of 435 samples collected were used. To refine the scale items, the exploratory factor analysis (EFA) was conducted repeatedly. Results - The business center service quality scale, made up of 8 factors and 33 items, was developed again. The 8 factors are reliability, speed, kindness, specialty, responsibility, appearance, convenience, and public interest. The reliability coefficient (Cronbach's Alpha) of each factor is greater than .7. Thus, it was confirmed that there was reliability in the measurement items. Further, the model suitability was verified using the confirmatory factor analysis (CFA), and the convergent validity and the discriminant validity were verified. This proved the construct validity. Through this process, the Korea Business Center Service Quality Scale was developed. Based on factor analysis, the developed business center service quality (BCSQ) scale consists of 4 aspects, 8 factors, and 33 items, comprising the "process quality" aspect: reliability (3 items), speediness (4 items), kindness (3 items) factors, the outcome quality aspect: expertise (3 items), responsibility (5 items) factors, the environment quality aspect: appearance (5 items), convenience (3 items) factors, and the public interest aspect: public interest (7 items) factor. However, according to CFA, the BCSQ scale consists of a total of 4 aspects, 8 factors, and 33 items, comprising the "process quality" aspect: reliability (3 items), speediness (3 items), kindness (3 items) factors, the outcome quality aspect: expertise (2 items), responsibility (4 items) factors, the environment quality aspect: appearance (3 items), convenience (2 items) factors, and the public interest aspect: public interest (3 items) factor. Conclusions - The BCSQ scale could serve as a diagnostic tool that will allow business center managers to determine service areas that are weak and in need of attention, and to improve the service quality of the business center.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.548-559
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• 2011

3-D Multi-geophysical surveys were carried out around the Hwasan caldera at the Euisung Sub-basin. To overcome the limitations of resolutions in previous studies, dense gravity data and magnetotelluric (MT) data were obtained and analyzed. In this study, the independent inversion models from gravity and MT data were integrated using correlation and classification approaches for 3-D imaging of the geologic structures. A Structure Index (SI) method was proposed and applied to the integration and classification analyses. This method consists of Type Angle (TA) and Type Intensity (TI) values, which are estimated by the spatial correlation and abnormality of the physical properties. The SI method allowed the classification analysis to be effectively performed. Major findings are as follows: 1) pyroclastic rocks around the central area of the Hwasan caldera with lower density and resistivity than those of neighboring regions extended to a depth of around 1 km, 2) intrusive igneous rocks with high resistivity and density were imaged around the ring fault boundary, and 3) a basement structure with low resistivity and high density, at a depth of 3-5 km, was inferred by the SI analysis.

• Journal of the Korean Ceramic Society
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• v.39 no.5
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• pp.503-510
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• 2002

Silicon carbide candle filters for the pressurized fluidized bed combustion system were fabricated by extrusion process. Carbon black was added to control the porosity. Inorganic additives such as clay and calcium carbonate were added to exhibit appropriate strength. Silicon carbide layer with a finer pore size (mean pore diameter ~$10{\mu}m$) was coated on the silicon carbide support layer (mean pore diameter ~$47{\mu}m$, porosity ∼40%). After that, the filter was sintered at 1400${\circ}C$ in air. We evaluated the filtration performances of the filter at 500${\circ}C$ and $5kgf/cm^2$ of pressure. As a result, high separation efficiency, >99.999% was measured. It is expected that silicon carbide candle filter can be successfully used for the pressurized fluidized bed combustion system.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.151-158
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• 2010

TCM-KWG (tissue culture medium waste after harvest of Korean wild ginseng) (panax ginseng) is left over of tissue culture medium used to grow Korean wild ginseng (KWG). The present study was conducted to investigate the effect of TCM-KWG on meat quality and the possible of application as additives in broiler chickens. A day old broiler chickens randomized in 6 groups (n=60/groups) were administered orally with 2, 4, 8, 16, 32 mL/L TCM-KWG through drinking water with one untreated control group. After administration for five weeks, we analyzed chemical composition and meat quality. Crude ash increased approximately 20% in TCM-KWG treatment groups as compared to control group whereas the concentration of moisture, crude protein and crude fat did not show any significant difference. Crude ash is essential to enhance skeleton formation and physiological function. TCM-KWG treatment gradually decreased the pH value of breast meat whereas it did not change the purge loss and cooking loss. The pH value of meat is important for preservation of meat for longer periods and high durability strength. These results suggest that TCM-KWG treatment may improve the quality of meat and can be apply as food additives in chickens.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.275-280
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• 2005

We propose a new approach to greatly simplify the fabrication of conventional nanoimprint lithography (NIL) by combined nanoimprint and photolithography (CNP). We introduce a hybrid mask mold (HMM) made from UV transparent material with a UV-blocking Cr metal layer placed on top of the mold protrusions. We used a negative tone photo resist (PR) with higher selectivity to substrate the CNP process instead of the UV curable monomer and thermal plastic polymer that has been commonly used in NIL. Self-assembled monolayer (SAM) on HMM plays a reliable role for pattern transfer when the HMM is separated from the transfer layer. Hydrophilic $SiO_2$ thin film was deposited on all parts of the HMM, which improved the formation of SAM. This $SiO_2$ film made a sub-10nm formation without any pattern damage. In the CNP technique with HMM, the 'residual layer' of the PR was chemically removed by the conventional developing process. Thus, it was possible to simplify the process by eliminating the dry etching process, which was essential in the conventional NIL method.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.135-139
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• 1993

Radionuclide cardioangiography has been widely applied and has played major roles in non-invasive assessment of cardiac function. Three techniques, first-pass, gated first and gated equilibrium methods, have commonly been used to evaluate right ventricular ejection fraction which usually abnormal in the patients with cardiopulmonary disease. It has been known that the gated first pass method is the most accurate method among the three techniques in assessment of right ventricular ejection fraction. The radionuclide right ventricular ejection fraction values were determined in 13 normal subjects and in 15 patients with chronic obstructive pulmonary disease by the gated first pass method and compared with those of the first pass method because there ha,j been no published data of right ventricular ejection fraction by the gated first pass method in Korea. The values of right ventricular ejection fraction by the gated first pass method were compared with the detas from the pulmonary function test performed in the patients with chronic obstructive pulmomary disease. The results were as follows: 1) The values of right ventricular ejection fraction by the gated first pass method were $50.1{\pm}6.1%$ in normal subjects and $38.5{\pm}8.5$ in the patients with chronic obstructive pulmonary disease. There was statistically significant difference between the right ventricular ejection fraction of each of the two groups (p < 0.05). 2) The right ventricular ejection fraction by the gated first pass method was not linearly correlated with $FEV_1$, VC, DLCO, and FVC as well as $P_aO_2$ and $P_aCO_2$ of the patients with chronic obstructive pulmonary disease. We concluded that right ventricular ejection fraction by the gated first pass method using radionuclide cardioangiography may be useful in clinical assessment of the right ventricular function.