• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2757-2760
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• 2003

본 논문에서는 심장 돌연사(sudden cardiac death, SCD)의 주된 원인인 세동(fibrillation)을 낮은 에너지에서 효율적으로 제거할 수 있는 biphasic 자동형 제세동기를 개발하였다. 개발한 제세동기는 고전압 충 방전부와 신호처리부를 포함하는 하드웨어와 세동검출 알고리즘과 시스템 제어 알고리즘의 소프트웨어로 구성하였다. 개발한 시스템의 안정성과 효용성을 검증하기 위하여, 실험실 환경에서 160 번의 연속적인 충 방전 테스트를 통하여 시스템의 안정성을 확인하였으며, ECG simulator 에서 발생되는 6 종의 세동신호를 적용하여 100％의 실시간 검출능력을 확인하였다.

• 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.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.658-664
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• 2006

$\rho$, $\alpha$-dimethyl benzyl alcohol was resolved by the biphasic dynamic kinetic resolution (DKR). Acidic zeolite was used as a racemization catalyst while immobilized enzyme was employed for kinetic resolution. The effects of the process variables including nature of acyl donor, reaction temperature, substrate concentration, ratio of the two catalysts and stirring rate on the conversion and enantiomeric purity of the product were investigated. In DKR of $\rho$, $\alpha$-dimethyl benzyl alcohol, the product of 99% ee was obtained with a maximum yield of 88%. The high performance of the catalyst system was maintained in the condition of higher TON and under repeated use.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.355-362
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• 2008

Purpose: The carrier for the delivery of bone morphogenetic proteins(BMPs) should also serve as a scaffold for new bone growth. In addition, predictable bone formation in terms of the volume and shape should be guaranteed. This study evaluated the ectopic bone formation of recombinant human BMP-2(rhBMP-2) using a micro macroporous biphasic calcium phosphate (MBCP: mixture of ${\beta}TCP$ and HA) block as a carrier in a rat subcutaneous assay model. Materials and Methods: Subcutaneous pockets were created on the back of 40 male Sprague-Dawley rats. In the pockets, rhBMP-2/MBCP and MBCP alone were implanted. The blocks were evaluated by histological and histometric parameters after a healing interval of 2 weeks (each 10 rats; MBCP and rhBMP-2/MBCP) or 8 weeks (each 10 rats; MBCP and rhBMP-2/MBCP). Results: The shape and volume of the block was maintained stable over the healing period. No histological bone forming activity was observed in the MBCP alone sites after 2 weeks and there was minimal new bone formation at 8 weeks. In the rhBMP-2/MBCP sites, new bone formation was evident in the macropores of the block. The new bone area at 8 weeks was greater than at 2 weeks. There was a further increase in the quantity of new bone with the more advanced stage of remodeling. Conclusions: A MBCP block could serve as a carrier system for predictable bone tissue engineering using rhBMPs.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.15-18
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• 1998

Membrane reactors are systems which combine a chemical reactor with a membrane separation process allowing to carry out simultaneously conversion and product separation. The catalyst can be immobilized on the membrane or simply compartmentalized in a reaction space by the membrane. Membrane reactors are today investigated to produce optically pure isomers and/or resolve racemic mixture of enantiomers. The interest towards these systems is due to the increasing demand of enantiomerically pure compounds to be used in the pharmaceutical, food, and agrochemical industries. In fact, enantiomers can have different biological activities, which often influence the efficacy or toxicity of the compound. On the basis of current literature there are basically two schemes on the use of membrane technology to produce enantiomers. In one case, the membrane itseft is intrinsically enantioselective: the membrane is the chiral system which selectively separates the wanted isomer on the basis of its conformation. In the other, a kinetic resolution using an enantiospecific biocatalyst is combined with a membrane separation process; the membrane separates the product from the substrate on the basis of their relative chemical properties (i.e. solubility). This kind of configuration is widely used to carry out kinetic resolutions of low water soluble substrams in biphasic membrane reactors [Giomo, 1995, 1997; Lopez, 1997]. These are systems where enzyme-loaded membranes promote reactions between two separate phases thanks to the properties of enzymes, such as lipases, to catalyse reactions at the org ic/aqueous interface; the two phases are maintained in contact and separated at the membrane level by operating at appropriate transmembrane pressure. A schematic representation of biphasic membrane reactor is shown in figure 1, while an example of enantiospecific reaction and product separation carried out with these systems is reported in figure 2.

• YAKHAK HOEJI
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• v.51 no.5
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• pp.301-306
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• 2007

Rosiglitazone ($Avandia^{(R)}$) represents a new class of antidiabetic drugs which are $PPAR{\gamma}$ agonists. The present study was undertaken to determine whether the new antidiabetic rosiglitazone influences on the agonist-induced regulation of vascular smooth muscle contraction as an antihypertensive and, if so, to investigate the related mechanism. Endothelium-denuded arterial rings from male Sprague-Dawley rats were used and isometric contractions were recorded using a computerized data acquisition system. Rosiglitazone decreased Rho-kinase activating agonist (NaF or thromboxane $A_2$ mimetic)-induced contraction but not depolarization- or phorbol ester-induced contraction. Surprisingly, it slightly potentiated the latter contraction possibly opening a voltage-dependent calcium channel by its chemical structure on 50 mM KCI- or $1{\mu}M$ phorbol 12,13-dibutyrate-induced vasoconstriction. In conclusion, this study provides the evidence and possible related mechanism concerning the biphasic effect of an antidiabetic rosiglitazone as a possible antihypertensive on the agonistinduced contraction in rat aortic rings regardless of endothelial function.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.2
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• pp.207-213
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• 2011

Purpose: The purpose of this study was to determine the preventive effect of joint mobilization on biphasic pain response induced formalin test. Methods: Sprague-dawley rats(n=30) were ramdomly divided into the control group without intervention, sham control group with application of hand contact without mobilization, joint mobilization group with application of hand contact with mobilization. Joint mobilization of knee procedure involved an grade III extension mobilization basically with anterior-posterior gliding of the tibia on the femur. Formalin injection caused biphasic pain response which is lated for 60 minute. The first phase result from primary afferent sensory fiber, wheareas the second phase has been proposed to central sensitization in the central nervous system. Behavioral analysis was performed by digital camera after 5% formalin subcutaneous injection into the dorsal foot. Results: Pain response of joint mobilization group show significant lower than control gorup and sham control group. Conclusion: This result suggest that pre-application of joint mobilization may be effective intervention to prevent the formalin induced pain.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.147-148
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• 2009

In this paper, we describe a telemetry stimulation system that controls animal-robots. In our system, we send the main control command from PC to the controller embedded in the pigeon based animal-robots. Once the controller receives the control signal, it makes biphasic stimulation pulses to medial forebrain bundle neurons to control the pigeon behavior as we want. We design the embedded controller using CUBLOC, which is lightweight for attaching on the pigeon.

• Environmental Mutagens and Carcinogens
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• v.23 no.3
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• pp.94-98
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• 2003

Quercetin and naringenin are representative flavonoids that not only exert anti estrogenic, cholesterol-lowering and antioxidant activities but also can modulate the metabolism of many xenobiotics. The activity of the specific form(s) of CYP450 is likely to be a major determinant of susceptibility to chemically induced carcinogenesis between which varies among between individuals due to different dietary habits as well as genetic characteristics. People consume cooked meat or fish together with various vegetables containing substantial amounts of quercetin and naringenin that can modify the enzyme activity of CYP1A2 to stimulate or to inhibit the mutagenic activities of HCAs. Heterocyclic amines (HCAs) produced by cooking meat products at high temperatures are promutagens that are activated by cytochrome P450 (CYP) lA2. Using a newly developed Salmonella typhimurium TA1538/1A2bc-b5 strain, we tested the effect of quercetin and naringenin on the mutagenicity of 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ). TA1538/1A2bc-b5 bears two plasmids, one expressing human CYP1A2 and NADPH-P450 reductase (NPR), and the other plasmid which expresses human cytochrome b5 (cyp b5). TA1538/1A2bc-b5 cells showed high activities of 7-ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD) associated with CYP1A2 and are very sensitive to mutagenesis induced by several HCAs. MeIQ was found to be the strongest mutagen among the HCAs tested in this system. Mutagenicity of MeIQ was enhanced 50 and 42% by quercetin at 0.1 and 1 mM, respectively, but suppressed 82% and 96% at 50 mM and 100 mM. Naringenin also increased the MeIQ-induced mutation about 37% and 22% at 0.1 and 1 mM, but suppressed it 32% and 63% at 50 mM and 100 mM concentrations, respectively, in TA 1538/1A2bc-b5 cells. Thus, they stimulated the MeIQ induced mutation at low concentrations, but strongly suppressed it at high concentrations. This biphasic effect of flavonoids was due to the stimulation or the inhibition of CYP1A2 activity in a dose-dependent manner judging by the activities of EROD or MROD in the Salmonella cells. Collectively, it is likely that the biphasic effects of quercetin and naringenin on the MeIQ-induced mutagenesis in S. typhimurium TA1538/CYP1A2bc-b5 were due to their differential modification of the CYP1A2 activity in these cells.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.523.1-523
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• 1986

To extend the spectrum of enzyme utilization in the organic solvent system, C. rugosal lipase was selected as a model enzyme because its substrate is soluble to organic solvent. One of the serious disadvantages in this system was the deactivation of the lipase. The pattern of lipase deactivation was the biphasic model. The activation energies for the deactivation were 14.05${\times}$10$^4$ KJ/Kg mole in the first phase and 3.59 ${\times}$ 10$^4$ KJ/mole in the second phase. The several factors were studied for their influences on the pattern of deactivation. Iso-octane as organic solvent influenced more on the first phase than the second phase. Urea as the reagent affecting boty hydrophobic interaction and hydrogen bond of enzyme also influencea more on the first phase. And the optimum pH for the activity was not correlated to that of the stability.