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법랑질 표면의 탈회 및 재광화 후 EPMA (electron probe micro-analysis)를 이용한 칼슘, 인, 불소 변화의 정량적 분석
홍경식,허복,이찬영,금기연,Hong, Kyoung-Sik,Hur, Bock,Lee, Chan-Young,Keum, Ki-Yeon 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5
The aim of this in vitro study was to analyze the composition of human tooth enamel in terms of three components, Ca, P, and F after demineralization and remineralization in acid buffer solution. A total of 8 human premolars without any defects and cracks were selected and buccal and lingual sides of the teeth were cleaned with an ultrasonic device and pumice without fluoride 5$\times$5mm windows were opened, and other areas were completely covered with 3-coats of nail varnish to prevent from being in contact with demineralized and remineralized solutions. After demineralization process, each tooth was sectioned into two slices, highly polished one of them with$\gamma$-alumina, and then analyzed the composition of the demineralized tooth with EPMA(electron probe micro-analyzer). The other slices were put into the remineralized solution for 10 days, polished, and analyzed in the same manner. These data were statistically analyzed with one sample t-test(p<0.05). The results were as follows. 1. Normal tooth enamel consists of 49.76% Ca, 39.80% P, and 0.28% F. 2. After demineralization, percentage of Ca and P ratio were decreased by about 5.57 and 5.07% respectively. Percentage of F ratio was also decreased by about 0.01%, which was not statistically significant. 3. After remineralization, percentage of Ca, P increased about by 4.47 and 4.35% respectively Percentage of F decreased by about 0.01%, which was not statistically significant. In conclusion, remineralized solution used in our study has the potential to induce the uptake the Ca and P into the pore sites of the demineralized enamel. But, in the oral cavity. there were rapid temperature change, organic matrix that inhibits the movement of the ions, and limitation of continuous contact with this remineralized solution. Therefore, further in vivo study is necessary.
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법량질 표면의 탈회 및 재광화 후 EPMA (electron probe micro-analysis)를 이용한 칼슘, 인, 불소 변화의 정량적 분석
홍경식,허복,이찬영,금기연 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5
The aim of this in vitro study was to analyze the composition of human tooth enamel in terms of there components, Ca, P, and F after demineralization and remineralization in acid buffer solution. A total of 8 human premolars without any defects and cracks were selected and buccal and lingual sides of the teeth were cleaned with an ultrasonic device and pumice without fluoride. 5×5mm windows were opened, and other areas were completely covered with 3-coats of nail varnish to prevent from being in contact with demineralized and remineralized solutions. After demineralization process, each tooth was sectioned into two slices, highly polished one of them withγ-alumina, and then analyzed the composition of the demineralized tooth with EPMA(electron probe micro-analyzer) . The ocher slices were put into the remineralized solution for 10 days, polished, and analyzed in the same manner. These data were statistically analyzed with one sample t-test(p<0.05) . The results were as follows. 1. Normal tooth enamel consists of 49.76% Ca, 39.80% P, and 0.28% F. 2. After demineralization, percentage of Ca and P ratio were decreased by about 5.57 and 5.07% respectively. Percentage of F ratio was also decreased by about 0.01%, which was not statistically significant. 3. After remineralization, percentage of Ca, P increased about by 4.47 and 4.35% respectively. Percentage of F decreased by about 0.01%, which was not statistically significant. In conclusion, remineralized solution used in our study has the potential to induce the uptake the Ca and P into the pore sites of the demineralized enamel. But, in the oral cavity, there were rapid temperature change, organic matrix that inhibits the movement of the ions, and limitation of continuous contact with this remineralized solution. Therefore, further in vivo study is necessary.
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신생 흰쥐 해마 절편 배양에서 산소-포도당 박탈에 의한 신경 세포 사망에 대한 성장호르몬의 효과
홍경식,강지희,김명주,유지숙,장영표 대한소아청소년과학회 2009 Clinical and Experimental Pediatrics (CEP) Vol.52 No.5
Purpose : To investigate whether growth hormone (GH) has a protective effect on neurons in hippocampal slice cultures of neonatal rats exposed to oxygen-glucose deprivation (OGD). Methods : Cultured hippocampal slices of 7-day-old rats were exposed to OGD for 60 min. Then, the slices were immediately treated with three doses of GH (5, 50, or 500 µM) in media. The relative fluorescent densities of propidium iodide (PI) uptake in the slices and relative lactate dehydrogenase (LDH) activities in the media were determined and compared between each GH- treated group of slices and untreated slices (control) at 12 and 24 h after OGD. Immunofluorescent staining for caspase-3 and TUNEL staining were performed to observe the effect of GH on apoptotic neuronal death. Results : The relative fluorescent densities of PI uptake in CA1 and dentate gyrus (DG) of the hippocampal slices in each GH-treated group were not significantly different from those in the untreated slices at 12 and 24 h after OGD (P>0.05). Treatment with GH could reduce the relative LDH activities in the media of the GH-treated groups only at 12 h after OGD (P<0.05). Expression of caspase-3 and TUNEL positivity in CA1 and DG of the slices treated with 50-ìM GH were not different from those of the untreated slices at 12 and 24 h after OGD. Conclusion : Treatment of hippocampal slice cultures with GH after OGD does not show a definitive protective effect on neuronal death but can reduce the LDH efflux of the slices in media at 12 h after OGD. 목 적 : 산소-포도당 박탈(oxygen-glucose deprivation, OGD)에 노출된 신생 흰쥐 해마 절편에서 성장호르몬이 신경 세포 보호 효과가 있는지를 연구하고자 하였다. 방 법 : 배양된 생후 7일된 신생 흰쥐의 해마 절편을 OGD에 60분간 노출 시켰다. 이후 각기 다른 세 용량의 성장 호르몬(5, 50, 500 µM)을 배양액에 투여하고 OGD 노출 후 12 와 24시간에 해마 절편의 상대적 propidium iodide (PI) uptake와 배양액의 상대적 lactate dehydrogenase (LDH) 활성도를 측정하여 성장 호르몬 처치군과 성장 호르몬 처치하지 않은 대조군 사이에 비교하였다. 신경 세포의 세포 사멸에 대한 성장호르몬의 효과를 관찰하고자 caspase-3의 면역 형광 염색과 TUNEL 염색을 시행하였다. 결 과 : 1) 각기 다른 세 용량의 성장호르몬을 처치한 해마 절편의 CA1과 DG에서 상대적 PI uptake는 처치하지 않은 대조군에 비해 OGD 노출 후 12시간과 24시간에 의미 있는 차이를 보이지 않았다(P>0.05). 2) 상대적 LDH 활성도는 OGD 노출 후 12시간에만 성장 호르몬을 투여한 군의 배양액에서 대조군에 비해 통계적으로 의미 있게 감소하였다(P<0.05). 3) 성장 호르몬(50 µM)으로 처치한 해마 절편의 CA1과 DG에서 caspase-3 발현과 TUNEL 양성의 발현은 OGD 노출 후 12와 24시간에 대조군과 차이를 보이지 않았다. 결 론 : OGD에 노출된 해마 절편에서 성장호르몬 처치는 확실한 신경세포 보호 효과를 보이지 않았으나 OGD 노출 후 12시간에 배양액으로 LDH 유출을 감소시킬 수 있었다.
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홍경식,정준하,안계형 한국ITS학회 2012 한국ITS학회논문지 Vol.11 No.2
본 연구에서는 수도권을 중심으로 구축ㆍ운영 중에 있는 ITS 무선통신 인프라인 UTIS를 활용하여 긴급차량 우선신호제어 시스템을 개발하였다. 신호교차로에서 긴급차량의 연속주행과 일반차량의 제어지체를 최소화하는 긴급차량 우선신호제어 시스템 구현을 위해 긴급차량의 진행방향(직/좌)을 사전에 파악이 가능하도록 하였으며, 긴급차량 우선신호 제어 방식을 현시삽입과 현시조정 모드로 구분하여 개발하였다. 또한, 시스템에 대한 현장 적용 가능성을 평가하기 위해 CORSIM 모형의 RTE 기능 활용을 통해 HILS 기반의 평가 시스템을 구성하여 EVP 제어 효과에 대한 검증을 수행하였다. 본 연구를 통해 개발된 긴급차량 우선신호제어 시스템은 기 구축된 ITS 인프라를 활용한 것으로 현장 적용 시 경제적이고 효율적인 구축이 가능할 것으로 기대된다. In this paper, we have developed the system of emergency vehicle preemption signal control based on UTIS(Urban Traffic Information System) which have been deployed and operated in the national capital area. It considered the turning direction(through or left turn) of emergency vehicle at the signalized intersection in order to provide the consecutive progression of emergency vehicle and minimize the control delay of passenger cars. we adopted several EVP control modes such as phase insertion and phase adjustment mode. Also, we evaluated the possibility of field implementation via simulation analysis using CORSIM RTE(Run Time Extension) based HILS(Hardware In the Loop Simulation). We expect that the result of this research contribute to providing the right-of-way to emergency vehicle in this country.
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홍경식,김다예,윤진수 경찰대학 치안정책연구소 2020 치안정책연구 Vol.34 No.2
최근 도시부 단속류 구간에서 과속으로 인한 사고가 지속적으로 발생함에 따라 경찰청에서는 도시부 내에 사고 예방 및 속도 저감 효과가 높은 구간단속시스템을 도입하였다. 도시부의 경우 연속류 도로와는 다르게 설치 시 추가적인 고려사항이 발생하므로 도심형 구간단속시스템의 확대 운영을 위해 이에 대한 검토가 필요한 실정이다. 따라서, 본 연구에서는 기준 검토 및 도심형 구간단속의 설치 효과 분석을 통해 도입방안을 제시하고자 하였다. 2018년 설치된 5개구간을 대상으로 통행속도 감소효과를 분석한 결과, 제한속도 초과율은 최대 49.8%, 최고속도 최대 23.6%, 85%ile 속도 최대 16.1%, 평균속도 최대 20.6%가 감소한 것으로 나타났다. 또한, 차량 매칭률 및 교통류 분석 결과 구간 내 유출입 차량과 신호로 인한 정체 이후 발생하는 과속으로 인해 안전성 및 실효성이 저해될 수 있음을 확인하였다. 분석 결과를 바탕으로 구간단속시스템의 설치 구간은 신호 연동 부여 구간이며, 구간 내의 신호교차로는 시종점을 포함하여 최대 5개 이내, 최소 구간길이 1km 이상, 시종점 통과차량 비율 최소 50% 이상 되는 곳을 선정하도록 제안하였다. 향후 본 연구결과를 토대로 경찰청과의 논의를 거쳐 도심형 구간단속시스템 도입 방안 수립에 활용할 예정이며, 이를 통해 정책 추진에 대한 합리적 근거를 마련할 수 있을 것으로 기대한다. Recently, section speed enforcement system(SSES)s for urban area have been installed to reduce the casualty crashes since 2017. Unlike SSES installed on highways, there are additional considerations when installing SSES for urban area because they are different from the traffic flow patterns. Therefore, this study proposed the recommended criteria of SSES for urban area through the review of criteria and analysis of installation effects. As a result for the installation effect analysis, the rate exceeding the speed limit, maximum speed, average speed and 85%ile speed were reduced by up to 49.8%p, 23.64%, 20.60% and 16.05%. But in some areas, it was found that the speed reduction effect was not significant because of congestion by signalized intersections and interrupted traffic flow. Based on the analysis results, this study suggested four recommended criteria of SSES for urban area. The recommended criteria that coordinated traffic signal is running, the number of signal intersections is 5 or less, the minimum section length is more than 1km and ratio of passing traffic is more than 50%. Based on this study, it will be used for establishing to SSES for urban area after discussion with the National Police Agency, and it is expected that this will provide a reasonable basis for policy implementation.
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