• 방사선산업학회지
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• 제9권3호
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• pp.127-130
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• 2015

Since the accident at the Fukushima Daiichi power plant, Prussian blue (PB) has attracted increasing attention as a material for use in decontaminating the environment. We have focused the fundamental mechanism of specific $Cs^+$ adsorption into PB in order to develop high-performance PB-based $Cs^+$ adsorbents. The ability of PB to adsorb Cs varies considerably according to its origin such as what synthesis method was used, and under what conditions the PB was prepared. It has been commonly accepted that the exclusive abilities of PB to adsorb hydrated $Cs^+$ ions are caused by regular lattice spaces surrounded by cyanido-bridged metals. $Cs^+$ ions are trapped by simple physical adsorption in the regular lattice spaces of PB. $Cs^+$ ions are exclusively trapped by chemical adsorption via the hydrophilic lattice defect sites with proton-exchange from the coordination water. Prussian blue are believed to hold great promise for the clean-up of $^{137}Cs$ contaminated water around nuclear facilities and/or after nuclear accidents.

• 한국농공학회논문집
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• 제55권2호
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• pp.9-20
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• 2013

Many studies have reported additional treatment is needed to use wastewater for agricultural purpose. Economic considerations should be taken into account to establish infrastructure for agricultural reuse because of a large amount of water use in irrigation and relatively low water quality requirement. The objective of this study was to conduct economic analysis of wastewater reclamation and reuse systems for agriculture. A system dynamics approach considering complexity and dynamics in the wastewater reuse systems was used for the economic analysis, which are related with social, environmental, and economic problems. Sensitivity and benefit cost analysis for wastewater reuse systems was conducted through the established economic assessment model. The result of sensitivity analysis showed that water resources development and installation cost were the most sensitive for total benefits and costs, respectively. The scenario-based test of the organized economic assessment model shows marginal cost ranges and enables decision-makers to decide reasonable cost for the wastewater reuse systems for agriculture.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.277-281
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• 2006

Spherical micro silica sol-gel immobilized enzyme beads were prepared in an emulsion system using cyclohexanone and Triton-X 114. The beads were used for the in situ immobilization of transaminase, trypsin, and lipase. Immobilization during the sol to gel phase transition was investigated to determine the effect of the emulsifying solvents, surfactants, and mixing process on the formation of spherical micro sol-gel enzyme beads and their catalytic activity. The different combinations of sol-gel precursors affected both activity and the stability of the enzymes, which suggests that each enzyme has a unique preference for the silica gel matrix dependent upon the characteristics of the precursors. The resulting enzyme-entrapped micronsized beads were characterized and utilized for several enzyme reaction cycles. These results indicated improved stability compared to the conventional crushed form silica sol-gel immobilized enzyme systems.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1505-1516
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• 2016

The detection of food pathogens is an important aspect of food safety. A range of detection systems and new analytical materials have been developed to achieve fast, sensitive, and accurate monitoring of target pathogens. In this review, we summarize the characteristics of selected nanomaterials and their applications in food, and place focus on the monitoring of biological and chemical contaminants in food. The unique optical and electrical properties of nanomaterials, such as gold nanoparticles, nanorods, quantum dots, carbon nanotubes, graphenes, nanopores, and polydiacetylene nanovesicles, are closely associated with their dimensions, which are comparable in scale to those of targeted biomolecules. Furthermore, their optical and electrical properties are highly dependent on local environments, which make them promising materials for sensor development. The specificity and selectivity of analytical nanomaterials for target contaminants can be achieved by combining them with various biological entities, such as antibodies, oligonucleotides, aptamers, membrane proteins, and biological ligands. Examples of nanomaterial-based analytical systems are presented together with their limitations and associated developmental issues.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.878-895
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• 2017

Phosphorylation, a critical mechanism in biological systems, is estimated to be indispensable for about 30% of key biological activities, such as cell cycle progression, migration, and division. It is synergistically balanced by kinases and phosphatases, and any deviation from this balance leads to disease conditions. Pathway or biological activity-based abnormalities in phosphorylation and the type of involved phosphatase influence the outcome, and cause diverse diseases ranging from diabetes, rheumatoid arthritis, and numerous cancers. Protein tyrosine phosphatases (PTPs) are of prime importance in the process of dephosphorylation and catalyze several biological functions. Abnormal PTP activities are reported to result in several human diseases. Consequently, there is an increased demand for potential PTP inhibitory small molecules. Several strategies in structure-based drug designing techniques for potential inhibitory small molecules of PTPs have been explored along with traditional drug designing methods in order to overcome the hurdles in PTP inhibitor discovery. In this review, we discuss druggable PTPs and structure-based virtual screening efforts for successful PTP inhibitor design.

• 정보저장시스템학회논문집
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• 제9권1호
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• pp.17-21
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• 2013

Optical coherence tomography (OCT) allows non-invasive, cross-sectional optical imaging of biological tissue with high spatial resolution and acquisition speed. In principle, it is analogous to ultrasound imaging, but uses near-infrared light instead of ultrasound, measuring the time-delay of back-scattered light from within biological tissue. Compared to ultrasound imaging, it exhibits superior spatial resolution (1~10 um) and high sensitivity. Therefore, OCT has been applied to a wide range of applications such as cellular imaging, ophthalmology and cardiology. Here, we describe a novel application of OCT technology in visualizing microneedles embedded in tissue that is developed to deliver drugs into the dermis without the injection mark in the human skin. Detailed three-dimensional structural images of microneedles and biological tissues were obtained. Examining structural modification of microneedles and tissues during insertion process would enable to evaluate performance of various types of microneedles in situ.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.166-169
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• 2012

In several biotechnological applications of living bacterial cells with inducible gene expression systems, the extent of overexpression and the specificity to the inducer are key elements. In the present study, we established the concentration ranges of $Zn^{2+}$, $Ni^{2+}$, $Co^{2+}$, ${AsO_2}^-$, and $Cd^{2+}$ ions that caused significant activation of the respective promoters of Synechocystis sp. without concomitant unspecific stress responses. The low expression levels can be increased up to 10-100-fold upon treatments with $Cd^{2+}$, ${AsO_2}^-$, $Zn^{2+}$, and $Co^{2+}$ ions and up to 800-fold upon $Ni^{2+}$ treatment. These results facilitate the development of conditional gene expression systems in cyanobacteria.

• 한국당과학회:학술대회논문집
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• 한국당과학회 2006년도 제1회 연례학술대회
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• pp.31-31
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• 2006

• 한국물환경학회지
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• 제22권5호
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• pp.757-767
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• 2006

Biological assessments are the primary tool for evaluating the biological condition of a water body and makes it possible to understand accumulative and long-term effect of stressors. They also provide reliable biological information for which disturbed systems are to be restored. Sustainable water environment is not enough with attaining only the clean water, but it should sustain healthy and diverse aquatic life. Aquatic organisms are affected by various factors, including not only water quality but also habitat condition and stressors, and thus good condition of both physical and chemical water quality is prerequisite for sustaining healthy organisms. Therefore, biological assessment, along with other physical and chemical assessments, are crucial for evaluating the health of a water body. Overall, sustainability of water environment demands the attainment and maintenance of ecological integrity, which is resulted from the combination of physical, chemical and biological integrity. The biological criteria will play very important role in the water resource management and policy issues, and thus bioassessment program should be fully implemented and supported eventually by the law. To keep ecosystem health of water environment safely from the toxic pollutants and other stressors, the following suggestions need to be considered in environmental quality standards in Korea. For the first step, the biological indicators need to be introduced in evaluating river quality condition; they provide a qualitative description of biological condition of water body. Secondly, the biological water quality standards using biotic indices should be developed and implemented under the consideration of characteristics of Korean river systems. Lastly, the ecological status classification regime (ESCR) should be developed and introduced; it could be used in quality assessment of the water environment in general. In developing ESCR, integration of physico-chemical, biological, and habitat parameters should be taken into account.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2457-2460
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• 2003

There is a great demand to manipulate biological cell autonomously since biologist should spend much time to obtain skillful manipulation techniques. For this purpose, we propose a cell chip to control, carry, fix and locate the cell. In this paper, we focus on the cell rotator to rotate individual biological cell based on a micro fluidics technology. The cell rotator consists of injection hole and rotation well to rotate a biological cell properly. Under the variation of flow rate in injection hole, the angular velocity of a biological cell is evaluated to find the feasibility of the proposed rotation method. As a practical experiment, Zebrafish egg is employed. Based on this research, we find the possibility of non-contact rotation way that can highly reduce the damage of the biological cell during manipulation. To realize an autonomous biological cell manipulation, a cell chip with manipulation well and micro channel in this research will be utilized effectively in near future.