• KSBB Journal
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• v.11 no.2
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• pp.140-150
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• 1996

To develop a home-version assay system for plasma lipoprotein cholesterol, variables that can control the assay performance were optimized. The system was constructcd by using two major components: nitrocellulose membrane strip with immobilized enzymes (cholesterol esterase, cholesterol oxidase, and horseradish peroxidase); and sample carrier solution containing non-ionic detergent (Triton X-100) and chromogen (3,3'-diaminobenzidine). Once a sample combined with the carrier was absorbed from the bottom of the strip, cholesterol was delivered by capillary action to the immobilized enzymes and a sequential reactions took place. In the final reaction, the chromogen was oxidized and then generated a color as signal that was proportional to the concentration of cholesterol. The signal intensity was enhanced by optimizing conditions for the immobilization of enzymes and the chemical composition of carriel. Under these conditions, a dose-response curve was obtained and revealed a high sensitivity enough to measure the cholesterol in blood.

• BMB Reports
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• v.42 no.4
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• pp.223-226
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• 2009

We measured the pH-induced spectral changes of yeast iso-1-cytochrome c on silver nanoparticle surfaces using surface-enhanced resonance Raman scattering (SERRS) at 457.9 nm. At a pH of ~3, the Met80 ligand in yeast iso-1-cytochrome c is assumed to dissociate, leading to a marked conformational change as evidenced by the vibrational spectral shifts. The Soret band at ~410 nm in the UV-Vis spectrum shifted to ~396 nm at pH~3, indicating a transition from a low spin state to a high spin state from a weak interaction with a water molecule. Thus, SERRS spectroscopy can measure the pH-induced denaturalization of cyt c adsorbed on metal nanoparticle surfaces at a lower concentration with a better sensitivity than ordinary resonance Raman spectroscopy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.988-1000
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• 1999

An experimental study is presented for the effect of number of terms of a pewee series type stress function on stress analysis around a hole in tensile loaded plate. The hybrid method coupling photoelastsic data inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width tensile plate. In order to measure isochromatic data accurately, actual photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. For qualitative comparison, actual fringes are compared with calculated ones. For quantitative comparison, percentage errors and standard deviations with respect to percentage errors are caculated for all measured points by changing the number of terms of stress function. The experimental results indicate that stress concentration factors analyzed by the hybrid method are accurate within three percent compared with ones obtained by theoretical and finite element analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.11
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• pp.1464-1469
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• 2000

The effects of SiCl$_4$addition on flame structures have been studied in flame hydrolysis deposition (FHD) processes using Coherent anti-Stokes Raman spectroscopy (CARS) and planar laser induced fluorescence (PLIF) to measure temperatures and OH concentrations, respectively. The results demonstrate that even a small amount of SiCl$_4$ addition can change thermal and chemical structures of H$_2$/O$_2$ diffusion flames. When SiCl$_4$ is added to a flame temperature decreases in non-reacting zone due to the increases in both specific heat and density of the gas mixture, while flame temperature increase in particle formation zone due to the heat release through hydrolysis and oxidation reactions of SiCl$_4$. It is also found that OH concentration decreases dramatically in particle formation zone where temperatures increase. This can be attributed to consumption of oxidative species and generation of HCl during silica formation.

• The Journal of Internal Korean Medicine
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• v.39 no.1
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• pp.1-8
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• 2018

Objectives: This study seeks to investigate the effects of Gamidohongsamul-tang (GDT) on the Gene expression levels of eNOS, KLF2, ICAM-1 and VCAM-1 in HUVEC cells. Methods: HUVEC cells were treated at a concentration of 1, 10, 100 (${\mu}g/ml$) of Gamidohongsamul-tang (GDT). To measure the NOS, KLF2, ICAM-1 and VCAM-1 gene expression in HUVEC cells, the synthesized cDNA was subjected to polymerase chain reaction (PCR) and electrophoresis was performed to verify gene expression level. Results: 1. GDT significantly increased eNOS and KLF2 gene expression. 2. GDT significantly reduced ICAM-1 and VCAM-1 gene expression. Conclusions: These experiments suggest that Gamidohongsamul-tang (GDT) regulates gene expression related with anti-dyslipidemic effects in HUVEC cells. In order to clinically apply this to diseases related to dyslipidemia, such as cardiovascular disease, additional in vivo experiments are needed to verify the anti-dyslipidemic effects of GDT.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.1
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• pp.19-23
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• 2020

Al-laminated packaging film incorporating ascorbic acid or tocopherol at inner food contact layer was tested in the potential to improve antioxidative preservation of powdered infant formula under CO₂-enriched atmosphere. Product of 200 g was packaged with the packaging film containing 0.3% antioxidant in sealant layer of low density polyethylene and stored at 30℃ for 286 days with periodic measurement of package atmosphere and product's quality attributes. The CO₂-flushed package resulted in shrinkage of tight contact between the product and the film not allowing gas sampling of package atmosphere after 140 days. Package of tocopherol-incorporated film allowed some ingress of oxygen after 112 days presumably due to its weakening of heat-seal area. The increased oxygen concentration in the tocopherol-added film package led to the concomitant increase of peroxide value, an index of lipid oxidation. On the other hand, packaging of ascorbic acid-added film pouch could suppress lipid oxidation marginally in consistent manner compared to control package without any antioxidant.

• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.91-96
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• 1995

The effects of toluene inhalation on the contents of amino acid neurotransmitters in rat brain were investigated and blood toluene concentrations inducing changes of behavior and amino acid neurotransmitter contents in rat brain were observed. Male wistar rats were exposed to toluene vapor (single dose : 1700, 5000 and 10000 ppm for 2 hrs, repeated dose : 1700 and 5000 ppm for 2 hrs/day$\times$6 days). Toluene concentrations in blood and the inhalation chamber were assayed by GC with headspace sampler. HPLC method following PITC derivatization was used to measure the amino acid contents in brain tissues such as frontal cortex, caudate, hippocampus, cerebellum and brain stem. Glutamic acid and aspartic acid levels were increased by single inhalation of toluene (5000 ppm) in all the brain areas assayed in this experiment. In caudate and cerebellum, taurine levels were decreased by single inhalation of low dose toluene (1700 ppm), but increased by repeated administration. At high blood toluene concentration, GABA levels were increased in all the brain areas assayed in this experiment and the increasing extents of inhibitory amino acid contents measured in caudate and hippocampus were greater than those of excitatory amino acids. These results suggest that the changes of amino acid neurotransmitter contents in brain by exposure to toluene may modulate toluene-induced behaviors.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.373-377
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• 2002

The Measurement of Pollution in the Troposphere (MOPITT) instrument is an eight-channel gas correlation radiometer launched on the Earth Observing System (EOS) Terra spacecraft in 1999. Its main objectives are to measure carbon monoxide (CO) and methane (CH4) concentrations in the troposphere. This work analyzes tropospheric carbon monoxide distributions using MOPITT data in East Asia and compared ozone distributions. In general, seasonal CO variations are characterized by a spring peak and decreased in the summer. Also, this work revealed that the seasonal cycles of CO are spring maximum and summer minimum with averaged concentrations ranging from 118ppbv to 170ppbv. The CO monthly means show a similar profiles to those of O3. This fact clearly indicates that the high concentration of CO in spring is caused by two possible causes: the photochemical CO production in the troposphere, transport of the CO in the northeast Asia. The CO and O3 seasonal cycles in northeast Asia are influenced extensively by the seasonal exchange of the different types of air mass due to the Asian monsoon. The continental air masses contain high concentrations of O3 and CO due to higher continental background concentrations and sometimes due to the contribution of regional pollution. In summer the transport pattern is reversed. The Pacific marine air masses prevail over Korea, so that the marine air masses bring low concentrations of CO and O3, which tend to give the apparent minimum in summer.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.639-646
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• 2005

In this research, we tried to develop the application method to water management and treatment using toxicity test method. When we measure the toxicity of environmental samples, we have to decide whether we take some countermeasures to reduce the toxicity or not. The first issue is how to set these action levels in each bioassays. A new idea was attempted to authorize indirect approach of each bioassays through the response characteristics against mixture of chemicals in water quality standard. The significant response in the cell-growth-inhibition bioassay was detected for standards-mixture(STDs). For acute toxicity assay, STDs-based implicit correlation between risks to humans and bioassay data showed a rational approach to set action levels in practical management. A simple model was proposed to describe and predict the changes in the total toxicity based on the concentrations of toxic-controlling chemicals during the ozonation of landfill leachates. On the basis of this simple model, toxicity reduction was predicted for pre-aggregation treatment before ozonation and ozone concentration during the ozonation. The method proposed in this study would be useful in optimizing water treatment processes and their running conditions in terms of the toxicity reduction efficacy.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.1
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• pp.29-36
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• 2004

Organics may be divided into biodegradable and nonbiodegradable fractions on the basis of biodegradability. Biodegradable organics may be subdivided into readily and slowly biodegradable fractions. As this biodegradability of organics in municipal wastewater has a great influence on the efficiency of a biological nutrient removal process, it has been assessed by respirometry. The respirometer, which consisted of a respiration chamber and a respiration cell, was used to measure the respiration rate of biomass utilizing the readily biodegradable organics. The readily biodegradable organics are about 10% of the COD in municipal wastewater. The adequate ratio of wastewater to sludge volume and the concentration of sludge are required in measuring the respiration rate due to the readily biodegradable organics. By using a biochemical oxygen demand test, the slowly biodegradable organics including biomass are estimated about 66% of COD. The soluble inert organics are about 11% of COD. On the basis of mass balance, the particulate inert organics are estimated about 13% of COD.