• Journal of Marine Bioscience and Biotechnology
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• v.1 no.1
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• pp.9-21
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• 2006

Foods and related substances from diverse sources known to have a potential for disease risk reduction are called functional foods, while nutraceuticals are bioactive compounds isolated from food and sold in dosage form. Nutraceutical and functional food industries are rapidly growing in recent years and most of the cases development of these functional materials involves certain biotransformation processes. A number of bioactive compounds has been identified up to date and isolated from seafood related products through enzyme-mediated hydrolysis. The enzymatic bioconversion process require suitable biocatalysts and appropriate bioreactor systems to incubate byproducts with digestive enzymes. Membrane bioreactor technology is recently emerging for the development of bioactive compounds from seafood processing byproducts.

• Ocean Science Journal
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• v.41 no.4
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• pp.221-226
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• 2006

More attention has been paid to the research on decolorization of dyeing wastewater nowadays. In this study, an investigation into the decolorization of dyeing wastewater was conducted using a combination of coagulant, carboxymethyl chitosan (NOCC) and coagulant aid, polyscrylamide (PAM). The factors influencing the decolorization efficiency, such as pH value, coagulant and the dosages of coagulant, were discussed. The results showed that using PAM as coagulant aid could reach a high decolorization efficiency compared with using NOCC alone. The optimal conditions were pH 2.3, 480 mg/L for NOCC, and 4-8 mg/L for PAM. Under the optimum conditions, the rate of decolorization could achieve 99%, and the removal of chemical oxygen demand (COD) could achieve 90%. In addition, the membrane processes with chitosan/rare-earth-metals could enhance the decolorization rate of Direct Black FF to 94.7%, and Indanthren Red F3B to 98.2%, respectively.

• Macromolecular Research
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• v.12 no.2
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• pp.145-155
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• 2004

Facilitated transport membranes for the separation of olefin/paraffin mixtures have long been of interest in separation membrane science because olefins, such as propylene and ethylene, which are important chemicals in petrochemical industries, are currently separated by energy-intensive cryogenic distillation processes. Recently, solid polymer electrolyte membranes containing silver ions have demonstrated remarkable performance in the separation of olefin/paraffin mixtures in the solid state and, thus, they can be considered as alternatives to cryogenic distillation. Here, we review recent progress, and critical issues affecting in the use of facilitated olefin transport membranes; in particular, we provide a general overview with reference to carrier properties, transport mechanisms, and separation performance.

• Biomolecules & Therapeutics
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• v.25 no.1
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• pp.26-43
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• 2017

Endocytosis is a process by which cells absorb extracellular materials via the inward budding of vesicles formed from the plasma membrane. Receptor-mediated endocytosis is a highly selective process where receptors with specific binding sites for extracellular molecules internalize via vesicles. G protein-coupled receptors (GPCRs) are the largest single family of plasma-membrane receptors with more than 1000 family members. But the molecular mechanisms involved in the regulation of GPCRs are believed to be highly conserved. For example, receptor phosphorylation in collaboration with ${\beta}$-arrestins plays major roles in desensitization and endocytosis of most GPCRs. Nevertheless, a number of subsequent studies showed that GPCR regulation, such as that by endocytosis, occurs through various pathways with a multitude of cellular components and processes. This review focused on i) functional interactions between homologous and heterologous pathways, ii) methodologies applied for determining receptor endocytosis, iii) experimental tools to determine specific endocytic routes, iv) roles of small guanosine triphosphate-binding proteins in GPCR endocytosis, and v) role of post-translational modification of the receptors in endocytosis.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.113-116
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• 2007

The fuel cell which converts directly chemical energy of fuel into electric energy has higher efficiency than the conventional power generation which involves several additional processes. Especially, polymer electrolyte membrane fuel cell (PEMFC) of which the electrolyte is a thin proton conductive polymer membrane is affordable for portable power applications and small-scale distributed power generation including household and small building. It is very important to not only increase the efficiency of FC itself but determine the optimal operation mode. The optimal operational planning of lkW household PEMFC system based on the daily electricity and heat demand patterns was performed. The estimated economic gain was up to 20% by adoption of PEMFC system.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.27-30
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• 1997

1. Introduction : Molecular diffusion of small molecules in polymers plays an important role in many areas where polymers are acting as barriers, and in separation processes, such as selective diffusion. Different applications of polymers have different requirements on their transport properties. Therefore, reliable predictions of diffusion coefficients for small molecules in polymeric materials could be a useful tool to design appropriate materials. For many years, the theories based on free-volume concepts have been widely used to correlate and predict diffusion behavior in polymer/solvent systems. In the theory derived by Vrentas and Duda, the empty space between molecules that is available for molecular transport, referred to as hole free-volume, is being redistributed. Molecular transport will occur only when a free-volume of sufficient size appears adjacent to a molecule and the molecule has enough energy to jump into this void. The diffusive jump is considered complete when the void left behind is closed before the molecule returns to its original position. In this paper, the Vrentas-Duda free-volume theory is presented and the methods to estimate free-volume parameters for predicting polymer/ solvent diffusion coefficients are described in detail.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.21-27
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• 2014

Recently, various biochip environments have been presented. In this study, a novel transparent film with porous membrane windows, which is an essential component in a co-cultured biochip environment, is fabricated using spin-coating, 3D printing, and electrospinning processes. In detail, a transparent polystyrene film was fabricated by means of the spin-coating process followed bywindow cutting, after which apolycaprolactone-chloroform solution was deposited along the window edge to introduce an adhesion layer between the PS film and the PCL nanofibers. Nanofibers were electrospun into the window region using a direct-write electrospinning method. Consequently, it was demonstrated that the fabricated window film could be used in a co-culture biochip environment.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.106-122
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• 1995

Industrialization has given humanity many benefits, such as material abundance and conveniences. However, it has also caused detrimental side effects to the environment which are becoming a global problem. During the 1960's, the national economic scale in Korea was expanded and personal lifestyles rapidly improved. These improvements also caused environmental problems such as water contamination. Water contamination caused by old, worn water pipes, harmful materials and deposits from the water purification processes decreased the tap water quality, causing unpleasant odors and tastes. Due to poor maintenance of the reservoir facilities of tap water quality, citizens lost their faith in the water quality. In the long term, it made us worry about the health of our nation's citizens (6,16).

• Korean Journal of Microbiology
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• v.28 no.4
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• pp.297-303
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• 1990

Secretion of Serratia marcescens nuclease by E. coli harboring pNUC4 was investigated. 29.2, 54.2 and 16.6% of total nuclease were observed in culture medium, periplasm, and cytoplasm of E. coli, respectively. To investigate the secretion mechanism of Serratia nuclease by E. coli, secretion kinetics of nuclease was examined in the presences of sodium azide, and energy metabolism inhibitor; procaine, an exoprotein processing inhibitor; and chloramphenicol, a protein synthesis inhibitor. In the presence of sodium azide, periplasmic unclease was gradually decreased and the extracellular nyclease was linearly increased according to the incubation time. Similar results were obtained in presences of procaine and chloramphenicol. From these results, we concluded that two transport processes are involved in nuclease secretion: secretion of nuclease through the inner membrane is occurred by an energy-dependent process and probably requiring precusor processing: secretion of nuclease through outer membrane does not require energy, de novo protein synthesis, and precursor processing.

• Archives of Pharmacal Research
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• v.3 no.1
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• pp.51-55
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• 1980

Thiamine, in the form of its diphosphate (TDP), is well known to act as a coenzyme, and during the early stage in the study of thiamine it had been believed that the symptoms of thiamine-deficiency were resulted secondarily from the disturbance of metabolic processes in which TDP participated as a coenzyme. However, the neurological symptoms in thiamine deficiency are now separated from the metabolic disturbances in thiamine deficiency. On the other hand, the specific involvement of phosphorylated thiamine in nerve conduction has been suggested by von Muralt, but nature of this involvement has not been elucidated at a molecular level. Recently the possible significance of thiamine triphosphate (TTP) in nervous tissue was suggested by the demonstration that TTP is not present in the brain of patients with subacute necrotizing encephalomyelitis, a fatal disease associated with an abnormality in thiamine metabolism. Furthermore, the studies using membrane fragments of rat brain strongly indicated that ion movement across the nerve membrane is associated with dephosphorylation of phosphorylated thiamine.