• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.61-62
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• 1993

고분자 분리막의 투과성과 선택성을 향상시키기 위하여 IPN막, 고분자/액정 복합막을 다양한 기능을 가진 재료가 개발되고 있다. 본 연구에서는 알칼리메탈이온을 분리하기 위하여 고분자 지지체에 운반체로써 crown ether(macro-cyclic polyether)류를 분산시킨 고분자/운반체 복합박막을 제조하였다. 고분자/운반체 복합박막은 고분자와 운반체의 혼합용액을 수면에 전개시켜 제조하였다. 고분자는 PVC(M.W 60000, Aldrich), PS(M.W 280000, Aldrich)와 CA(M.W 30000, Sigma)를 사용하였고, 운반체로는 crown ether 중 $K^+$이온과 선택성을 가지는 18-Crown-6(Sigma)를 사용, 고분자와 18-Crown-6의 증량분을 달리하는 혼합용액을 제조하였다. 이때 용매는 Tetrahydrofuran를 사용하였다. 수면에 생성된 박막을 다공성 지지막에 적층시킨 후 감압 건조시켜 복합막을 제조하였다. 고분자와 운반체가 혼합되어 있는 용액의 점도와 표면장력을 각각 fluid spectrometer와 tensionmeter를 사용, 용액이 수면위에서 완전한 막을 형성하면서 분산될 수 있는지 조사하였으며, 고분자 지지체에 분산 고정된 운반체의 분산형태와 표면농도를 조사하기 위하여 ESCA를 이용하였다.

• Journal of Life Science
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• v.27 no.7
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• pp.840-848
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• 2017

Proper intracellular transport is essential for normal cell function. Intracellular transport is mediated by microtubule-dependent molecular motor proteins, as well as kinesin and cytoplasmic dynein, which move their cargo along long, microtubule tracks in cells. Kinesins are ATP-dependent plus-end-directed motor proteins in the intracellular transport of organelles, vesicles, RNA complexes, and protein complexes. The mislocalization of these different types of cargo has been linked to cell dysfunction and degeneration. The cargo transport of kinesins can be described by the following steps: binding to the appropriate cargo and/or adaptor proteins, activation of the kinesin's motility and movement along the microtubule, and the release of the cargo at the correct destination. Recently, several studies have revealed the mechanisms for the regulation of kinesin motor activity, including cargo loading and unloading. Intracellular cargo transport is also modulated by adaptor proteins, which link the kinesins to their cargo. The regulatory proteins, which include protein kinases and phosphatases, regulate kinesin motor activity directly through the phosphorylation or dephosphorylation of kinesins and indirectly through the modification of adaptor proteins, such as c-Jun NH-terminal kinase-interacting proteins, or of the microtubule network. These findings lay the groundwork for understanding how kinesins are differentially engaged in intracellular cargo transport. In addition, understanding the regulatory mechanisms of each kinesin is an area of key interest within cell biology and neurophysiology. In this study, we reviewed kinesins' regulation proteins and discuss how their regulation affects cargo recognition and transport.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.476-483
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• 1988

Yeat-Escherichia coli shuttle vectors were constructed by combination of various functional segments such as autonomous replicating sequence (ARS1), centromere region (CEN3), origin of replication of 2 $\mu$m plasmid (2 $\mu$m OR). Transformation efficiency, stability and copy number of constructed vectors were analyzed in yeast strains, SHY4(cir$^+$) containing 2 $\mu$m plasmid and NNY1(cir$^{\circ}$) without it. The results showed that centromere containing plasmids were very stable and existed at one copy per cell; fused replication system (2$\mu$m OR and ARS1) containing Plasmids were more stable and higher copy number than one replicon containing plasmids ; presence of endogenous 2$\mu$m plasmid influenced on stability and copy number of 2 $\mu$m based plasmids.

• Journal of Periodontal and Implant Science
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• v.37 no.sup2
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• pp.397-407
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• 2007

골형성 유도 단백질(bone morphogenetic protein, BMP)은 성장이나, 골형성과정에서 중용한 역할을 한다고 입증되었고 그것의 운반체에 대한 연구가 이뤄져 왔다. 하지만 수직압이 존재하는 곳에서 골증대술에 적용할 수 있을 만큼 강한 공간유지능력이 있는 운반체에 대한 연구는 그리 많지 않았다. Macroporous biphasic calcium phosphate block (MBCP block)은 공간유지능력이 뛰어나며 강한 수직압을 견딜수 있는 골대체물질이다. 이 연구의 목적은 MBCP block을 골형성유도 단백질(rhBMP-2)의 운반체로 사용하여 백서 두개골 결손부에 적용하였을 때, 골 형성 효과를 평가하는 것이다. 36마리의 웅성백서에서 8mm 지름을 갖는 임계크기의 두 개부 결손을 형성하였다. 20마리씩 2개의 군으로 나누어 MBCP block만 이식한 군, MBCP block을 운반체로 사용하여 농도 0.025mg/ml rhBMP-2를 이식한 군으로 나누어 술 후 2주와 8주에 치유결과를 조직학적, 조직계측학적으로 비교 관찰 하였다. 조직계측학적 관찰 결과, rhBMP-2/MBCP block 군에서 MBCP block군에서 보다 2, 8주 모두 골밀도(bone density)가 유의성있게 증가하였다 (P<0.01). 각 군에서도 8주째가 2주째보다 골밀도가 유의성있게 증가하였다(P<0.01). 총조직 형성량 (augmented area)에서는 변화가 없었다. 이 연구 결과, 백서 두개골 결손부에서 MBCP block은 rhBMP의 운반체로 사용하였을 때 신생골 형성에 유의한 효과가 있을뿐 아니라 공간유지능력이 우수해서 수직압이 존재하는 골증대술(bone augmentation)시 rhBMP의 운반체로 가능성이 있다고 사료된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1770-1774
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• 2011

This paper was to characterize the transfer of diacylglycerol(DAG) from lipophorin to Manduca sexta larval fat bodies. $[^3H]$-DAG-labeled Lp($[^3H]$-DAG-Lp) was incubated with the larval fat bodies under different times and the time of DAG transfer was determined. Incubation of fat bodies with $[^3H]$-DAG-Lp resulted in accumulation of DAG and TAG in the tissue. The transfer of $[^3H]$-DAG was inhibited in the presence of suramin and unlabeled lipophorin, which would be consistent with a lipophorin receptor. The effects of suramin may be complex because it can change membrane properties when bound to the lipophorin receptor and affect the rate of DAG transfer. To investigate the lipid uptake via receptor-mediated endocytosis, we treated with endocytosis inhibitors, ammonium chloride and chloroquine. The results show that the transfer process of lipid by lipophorin and fat bodies is receptor-mediated endocytosis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.958-960
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• 2015

Sickle cells possess a unique combination of traits that may enable their use as models for novel synthetic tumor targeting controlled release drug carriers with the ability to treat disseminated tumors in advanced metastatic disease. In this study, we assess the ability of light-activated release sickle cells to enhance tumor delivery of the fluorescent dye calcein by delayed photolysis controlled release compared to free systemic administration of calcein. Sickle cells from mouse models of the disease were shown to preferentially accumulate in tumors compared to adjacent tissue, in 4T1 tumors in mice on a time scale about 12 hours. Sickle cells photosensitized with protoporphyrin IX achieved delayed release of 50% of contents 8-16 hours after photoactivation, which was deemed useful for in vivo delivery of cargo to tumors given the tumor accumulation time of the sickle cells. Sickle cells may be useful as a model for new synthetic drug carrier particles with delayed photolysis controlled release properties.

• Korean Journal of Plant Tissue Culture
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• v.24 no.5
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• pp.269-272
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• 1997

Cotyledonary petioles of Brassica napus cocultivated with Agrobacterium vectors for 72 h were transferred to MS medium with 0.5 mg/L NAA, 2.0 mg/L BA, 30 mg/L kanamycin, 100 mg/L cefotaxime, 30 g/L sucrose, 3 mg/L $\textrm{AgNO}_{3}$ and 2 g/L Gelrite. The cotyledonary petioles with green shoots were selected at a frequency of 17.5% in a selection medium and then rooted. Southern blot analysis confirmed the rolC and NPT IIgenes were incorporated into the regenerated plants. The stable inheritance of rolC gene was confirmed in progeny test of transgenic plants.

• Journal of the Korean Chemical Society
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• v.28 no.3
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• pp.170-175
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• 1984

The transport rates of $H^+$ ion by DBC and DCC as carrier molecules through organic liquid membranes were determined at 25$^{\circ}$C. The transport rates depend highly on the dielectric constants of membrane solvents and these results were discussed in terms of Born's potential energy barrier methods. The sizes of anions also affect the transport rates and these results were well explained theoreticlly by extended Born's equation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.32-38
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• 1999

An autonomous mobile vehicle for transport system must plan optimal path in work envimnrent without human supervision and obstacle collision. This is to reach a destination without getting lost. In this paper, a genetic algorithm for globaI and local path planning and collision avoidance is proposed. The genetic algorithm searches for a path in the entire and continuous free space and unifies global path planning and local path planning. The sinmulation shows the proposed method is an efficient and effective method when compared with the traditional collision avoidance algorithms.rithms.

• Membrane Journal
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• v.27 no.3
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• pp.205-215
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• 2017

Polymer membranes are cheap and easy in fabrication, and show a high permeability and selectivity, thus play pivotal roles in gas separation as well as water purification. However, polymer membranes typically exhibit the trade-off relation between permeability and selectivity; i.e. when the permeability is high, the selectivity is low and vice versa. Facilitated transport has been considered one of the solutions to address this issue. Over the last decades, facilitated transport concept had played an important role in preparing the membranes and providing ideal and various models for the transport. Understanding the nature of carrier, the mobility of matrix and the physico-chemical properties of polymer composites are crucial for facilitated transport. Depending on the mobility of carrier, facilitated transport membrane is classified into three; mobile carrier membrane, semi-mobile carrier membrane, fixed-site carrier membrane. Also, there are four types of reversible reaction between the carrier and the specific target; proton transfer reaction, nucleophilic addition reaction, p-complexation reaction and electrochemical reaction. The facilitated transport membranes have been applied in the separation of CO2, O2 and olefin (propylene or ethylene). In this review, major challenges surrounding facilitated transport membranes and the strategies to tackle these challenges are given in detail.