• 한국해양학회지
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• 제21권2호
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• pp.110-117
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• 1986

본 연구 해역에서의 동물성 부유 생물에 의한 NH$_{4}$ 분비율은 0.90에서 2.32$\mu\textrm{g}$ atoms NH $_{4}$ -N.m$^{-3}$.h$^{-1}$의 범위를 보이며, 이에 의해 해 양 기초생산에 필요한 총질소요구량의 3내지 15%을 공급함을 밝혀졌다. 동물성 부 유생물의 습중량 및 단백질량의 정량결과, 외부연안수로 갈수록 그 양이 증가되는 경향을 나타내었다. 동물성 부유생물의 가장 중심적인 생화학적 단위인 GDH의 활 성도를 측정한 결과, 전형적인 Michaelis-Menten 효소기작을 보였다. 단백질 단위 GDH활성도는 본 연구 해역에서 1.5에서 3.2$\mu\textrm{g}$ atoms NH $_{4}$ -N mg$^{-1}$protein h$^{-1}$의 범위를 보였다. 외해수에서 동물성 부유생물의 GDH활성도가 높게 나타난 것은 조사당시의 외해수에서의 높은 기초 생산량을 포식하는 동물성 부유생물의 활발한 질소대사가 이루어지고 있음을 암시 한다. 본 연구를 통하여 한국 동남해역의 동물성 부유생물의 GDH활성도와 NH $_{4}$ 분비율 사이에 매우 높은 상관계가 밝혀졌으며 그 평균 GDH 활성도/ NH $_{4}$ 분비율의 비율은 18.8$\pm$2.6(n=6) 이었다. 차후 GDH활성도 측정등을 통 한 생화학적 효소연구방법은 여러 해양 환경에서 생물활동에 의하여 영향를 받는 비보전적인 해수원소의 동적 변화 및 해양생태계내에서의 각 생물군의 여러 생화학 적 역할을 규명하는데 중요하게 이용될 것으로 판단된다.

• 한국수자원학회논문집
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• 제53권spc1호
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• pp.813-826
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• 2020

본 연구는 2014년부터 2016년까지 경기도 파주시에 도입된 스마트워터시티(Smart Water City, SWC) 사업의 효과를 사업목표 대비 달성도 중심으로 분석한다. SWC란, 상하수도 시설에 ICT를 접목하여 물 관리의 효율화를 도모하는 스마트 물 관리시스템(Smart Water Management System, SWMS)을 바탕으로 건강한 물 공급체계를 구현한 물의 도시를 말한다. 본 연구는 SWC 사업의 효과성을 평가하기 위하여 사업목표에 상응하는 평가 기준을 수립하고, 사업 시행 전후의 값(산출물)을 비교 분석한다. 분석 결과, SWC는 공급과정의 수량 및 수질 관리를 강화하고 수돗물의 신뢰도 및 음용률을 제고하는데 기여하였다. 구체적으로는 평균 유수율 및 누수저감량 향상, 수질감시시스템의 확산, 배수관로의 부유성 입자농도 및 탁도 감소 등을 달성하였다. 이는 명확한 목표 설정과 달성을 위한 구체적인 실행 방안, 그리고 시민들을 위한 적극적이고 집중적인 서비스가 제공되었기에 가능하였다. 수량 및 수질과 관련된 대부분의 수치상에서 SWMS 도입 이전 대비 개선된 성과를 보였다는 점은 스마트워터시티의 긍정적인 효과로 볼 수 있다. 그러나 산출물에 대한 계량화된 분석은 긍정적인 변화에 끼친 다른 외부요인을 밝히는 데는 한계를 보인다. 향후에는 SWC 확산을 위한 가이드라인과 더욱 포괄적이고 구체적인 평가지표가 마련되어야 하며, SWMS은 이용자의 필요를 고려하여 개발되어야 할 것이다.

• Restorative Dentistry and Endodontics
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• 제26권4호
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• pp.296-306
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• 2001

The purpose of this study was to observe the effect of dexamethasone and osteogenic protein-1(BMP-7) on bone, cementum and periodontal tissue regeneration. A total of 60 Sprague-Dawley white female mice were selected and beta-APN was used for five days to extract the maxillary first molar a traumatically. After the extraction of the teeth, the mesiobuccal root canal was filled with Caviton$^{\circledR}$. The teeth were etched with citric acid for 1 min and coated with one of four different experimental solutions : DEX(500nM/ml), DEX(1000nM/ml), OP-1(100$\mu\textrm{g}$/ml) and OP-1(500$\mu\textrm{g}$/ml) for three minutes depending on the group. All teeth were then replanted under microscope. All replantation procedures were done within 30 minutes. Teeth that were replanted after 30 minutes of bench dry only was used as positive control. All animals were sacrificed at 3 weeks following replantation and histologic observtion was done. The results were as follows ; 1. Active root resorption rate was decreased by the order of OP-1(500$\mu\textrm{g}$/ml), DEX(1000nM/ml), OP-1(100$\mu\textrm{g}$/ml), and DEX(500nM/ml). There was statistically less root resorption in OP-1 (500$\mu\textrm{g}$/ml) and DEX(1000nM/ml) group(P<0.05). 2. The group with higher concentration of dexamethasone(1000nM/ml) had statistically more bone union compared to positive control group(P<0.05),but there were no significant differences among four experimental groups. 3. OP-1(500$\mu\textrm{g}$/ml) and DEX(1000nM/ml) groups showed less degree of inflammation compared to the OP-1(100$\mu\textrm{g}$/ml). DEX(500nM/ml), and positive control group (P<0.05). In conclusion, the group with higher concentration of OP-1 had the best results on root resorption, bone ankylosis and anti-inflammatory effects compared to the other experimental groups, but a long-term study is also necessary to evaluate the exact pharmacological effects of the drugs in the future.

• 디지털융복합연구
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• 제11권11호
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• pp.107-115
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• 2013

대전의 원도심은 인구감소 건물의 공동화 현상으로 옛 중심시가지를 비롯하여 인근 도시공간의 쇠퇴가 현저하게 진행 되어왔다. 이러한 문제를 해결하기 위해서는 개성을 살린 활성화 방안이 필요하지만, 어떤 한 시점을 기준으로 파악할 수 있는 역사와 문화적 자원을 활용하여 지역사회의 재생공간을 만들 수 있는 방안 마련도 중요하다. 대전의 원도심은 일단 그 공간을 지탱 해 온 산업에 대한 건축물 등, 지역의 건축적 문화유산이 다수 존재하고 있으며, 그 대부분은 보편적 가치를 가지고 있음에도 불구하고 아무런 활용방안이 마련하지 못한 채 피폐해져가는 실정이다. 이에 역사적으로 지역의 발전에 초석이 된 역사자원으로써 근대산업유산에 중요성과 가치를 평가하기 위한 기준을 알아보고, 활용사례를 통해 근대도시 대전의 발전에 근간이 되어온 산업유산에 가치와 활용을 재검토하는 의미로 근대 산업유산의 보존 및 대상을 활용한 도시재생 방안에 필요성을 알아보고자 하였다. 또한 행정적인 노력에 한계점을 인식하고, 이에 따른 해결방안을 모색하여 지방자치단체와 민간 등 폭넓은 사람들에 일체적 노력의 필요성을 다루고자하였다. 이는 결과적으로 지역 활성화에 있어서 역사적 근대산업유산을 활용을 통해 도시 사용자 간의 커뮤니케이션과 공동체 문화공간으로 재생되도록 정책의 연구와 산업유산을 포함하는 경관적 범위의 보존, 사회단체나 사회적 기업과 연계된 보존을 전제로 한 능동적이고 개방적인 문화재 활용정책을 마련하고, 이를 위해 소유자간의 조정 등에 노력이 전제한 정책이 필요하다는 것을 제언하고자 한다.

• 전력전자학회논문지
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• 제7권2호
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• pp.205-213
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• 2002

본 논문에서는 직류모선에서 교류모선으로 회생되는 전력을 제어할 수 있는 3상 전압원 인버터 시스템을 구현하였다. 전체 시스템은 선간접압 및 선전류용 센서, d-q 변환방식을 사용한 실제전력 연산기. PI제어기법을 적용한 복소전력 제어기, 수정 ｑ도통방식을 구현하기 위한 게이팅신호 생성기, 주파수를 추종하기 위한 DPLL과 전력회로로 구성된다. 제어보드는 32비트 DSP인 TMS32C32, EFLD 2개, ACD 6개와 DAC로 구성하였다. 제안한 시스템의 성능을 검증하기 위해 교류 220V에서 5kVA 전력용량인 축소모델을 설계, 제작하였다. 실험결과, 회생 유효전력은 명령값으로 잘 제어되며 회생 무효전력은 운전동안 내내 거의 0의 값을 유지함을 확인하였다.

• Journal of Korean Dental Science
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• 제4권1호
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• pp.26-32
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• 2011

Purpose: The quality of implant surface is one of the factors that influence wound healing of implant site and subsequently affect osseointegration. The objective of modification of the surface properties of an implant is to affect the biological consequence. The purpose of this study is to evaluate the biologic response of osseous tissue to anodized implants. Materials and Methods: Two machined titanium implants for control group were installed in a tibia of each rabbit and two anodized implants for test group were installed in the other tibia of each rabbit. At the moment the implants were installed, resonance frequency analysis (RFA) values were measured. After healing periods of 1, 2, 3, and 7 weeks, the implants were uncovered and RFA values were measured again. Removal torque was measured for one implant in the test group and one implant in the control group. Histological evaluation was executed in the other implants. Results: Both of test group and control group have the tendency of greater RFA change rate and removal torque value as healing periods became longer, but were statistically insignificant (P>0.05). However, in the case of the same healing period, the test group tended to have greater RFA change rate and removal torque than the control group (P<0.05). More active new bone formation from endosteal surface was noted on the anodized surface than machined surface in specimen after 1 week. There were no significant differences between the test group and control group in histological evaluations. Conclusion: In summary, the anodized surface showed slightly favorable results and it is postulated that it may facilitate improved stability in bone.

• Corrosion Science and Technology
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• 제17권2호
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• pp.68-73
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• 2018

Substitution of hip and knee joints by CoCr alloys is in great demand due to their high wear resistance and good biocompatibility. Understanding of tribocorrosion in joint replacements requires study of variables such as coefficient of friction and the choice of a proper corrosive medium in wear-corrosion tests carried out in the lab. The objective of this study was to characterize tribocorrosion behaviour of CoCr alloy with low (LCCoCr) and high carbon (HCCoCr) contents in several corrosive media: NaCl, Phosphate Buffer Solution (PBS), and PBS with hyaluronic acid (PBS-HA). Tribocorrosion tests were carried out on a pin-on-disk tribometer with an integrated electrochemical cell. A normal load of 5N was applied on the alumina ball counterpart at a rotation rate of 120 rpm. Coefficient of friction (COF) was measured and tribocorrosion behaviour was characterized by in situ application of electrochemical techniques. HCCoCr alloy immersed in PBS-HA showed the best tribocorrosion behaviour with the lowest COF. In this case, in situ measurement of corrosion potential and the impedance data under wear corrosion process showed an active state while passive film was continuously destroyed without possibility of regeneration.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.105-109
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• 2015

NgR1, a Nogo receptor, is involved in inhibition of neurite outgrowth and axonal regeneration and regulation of synaptic plasticity. P19 embryonal carcinoma cells were induced to differentiate into neuron-like cells using all trans-retinoic acid and the presence and/or function of cellular molecules, such as NgR1, NMDA receptors and STAT3, were examined. Neuronally differentiated P19 cells expressed the mRNA and protein of NgR1, which could stimulate the phosphorylation of STAT3 when activated by Nogo-P4 peptide, an active segment of Nogo-66. During the whole period of differentiation, mRNAs of all of the NMDA receptor subtypes tested (NR1, NR2A-2D) were consistently expressed, which meant that neuronally differentiated P19 cells maintained some characteristics of neurons, especially central nervous system neurons. Our results suggests that neuronally differentiated P19 cells expressing NgR1 may be an efficient and convenient in vitro model for studying the molecular mechanism of cellular events that involve NgR1 and its binding partners, and for screening compounds that activate or inhibit NgR1.

• 대한치과교정학회지
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• 제22권2호
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• pp.373-388
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• 1992

The purpose of this study was to clarify the histologic changes in the expansion of midpalatal suture by the tensile forces. 39 Sprague-Dawley rats were divided into a control group (3 rats) and three experimental groups (36 rats) -group 1, pressured with a light force(50-75 g), group 2, with a heavy force(250-300 g) and group 3, with a heavy force (250-300 g) plus laser irradiation. Autoradiographic and histopathologic observations were performed in 12, 24, 48 and 96 hours after force delivery. The results were as follows; 1. The anterior portion of midpalatal suture was more separated than the posterior portion in all experimental groups. Group 2 showed more separation than group 1 and no difference to group 3 2. Ligament tearing appeared intensively in 24 hours, but the sutural matrices increased with times. ; Group 2 showed more tearing than group 1, and active regeneration of sutural matrices was observed in group 3. 3. Vascular dilatation appeared intensively in 24 hours and decreased with times. ; The anterior portion of midpalatal suture showed more dilatation than the posterior portion, ; The changes was the greatest in group 3, group 2, group 1, in that order. 4. New bone formation and the new capillary prolieferation began to appear in 12 hours and increased with times, : Group 2 showed more changes than group 1 and no difference to group 3. 5. Infiltration of inflammatory cells was little observed and was the greatest in group 2, group 1, group 3, in that order 6. Positive reaction of cells to $[^3H]$ thymidine was the greatest in 24 hours, and decreased with times ; The reaction was the greatest in group 3, group 2, group 1, in that order.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.621-628
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• 2008

Purpose: Osteopontin is one of the major non-collagenous protein of hard tissue. Use of peptide domain of biologically active protein has some advantages. The objective of this experimental study is evaluation of periodontal regenerative potency of synthetic peptide gel which containing collagen binding domain of osteopontin in the degree III periodontal defect of beagle dogs. Material and Methods: Experimental degree III furcation defect was made in the mandibular third and fourth premolar of beagles. Regenerative material was applied during flap operation. 8 weeks after regenerative surgery, all animals were sacrificed and histomorphometric measurement was performed to calculate the linear percentage of the new cementum formation and the volume percentage of new bone formation. Result: The linear percent of new cementum formation was 41.6% at control group and 67.1% at test group and there was statistically significant difference. The volume percent of new bone formation was 52.1% at control group and 58.9% at test group. Conclusion: As the results of present experiment, synthetic peptide gel containing collagen binding domain of osteopontin significantly increase new bone and cementum formation in the degree III furcation defect of canine mandible.