Isolation and In Vitro Culture of Vascular Endothelial Cells from Mice

최신규,김지예,김관창,서석효 대한약리학회 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.1

In cardiovascular disorders, understanding of endothelial cell (EC) function is essential to elucidatethe disease mechanism. Although the mouse model has many advantages for in vivo and in vitroresearch, efficient procedures for the isolation and propagation of primary mouse EC have beenproblematic. We describe a high yield process for isolation and in vitro culture of primary EC frommouse arteries (aorta, braches of superior mesenteric artery, and cerebral arteries from the circle ofWillis). Mouse arteries were carefully dissected without damage under a light microscope, and smallpieces of the vessels were transferred on/in a Matrigel matrix enriched with endothelial growthsupplement. Primary cells that proliferated in Matrigel were propagated in advanced DMEM with fetalcalf serum or platelet-derived serum, EC growth supplement, and heparin. To improve the purity ofthe cell culture, we applied shearing stress and anti-fibroblast antibody. EC were characterized bya monolayer cobble stone appearance, positive staining with acetylated low density lipoprotein labeledwith 1,1’-dioctadecyl-3,3,3’,3’-tetramethyl-indocarbocyanine perchlorate, RT-PCR using primers forvon-Willebrand factor, and determination of the protein level endothelial nitric oxide synthase. Oursimple, efficient method would facilitate in vitro functional investigations of EC from mouse vessels.

슬릿트형 사방댐의 배치에 따른 토석류 흐름에 대한 영향: 축소모형실험 연구

최신규,이정민,정한범,김지헌,권태혁 한국방재학회 2015 한국방재학회논문집 Vol.15 No.3

토석류는 집중호우 시 경사가 급한 비탈면에서 자연사면의 붕괴로 인한 토사가 강우와 혼합되어 빠르게 흐르는 현상이다. 중력에 의해발생되는 이러한 현상은 빠른 이동 형태를 보이고 경사가 낮은 지역을 만나면서 퇴적되는데, 이 과정에서 인명과 재산에 막대한 피해를 입히게 된다. 이러한 이유로 토석류를 막기 위한 구조물이 많이 건설되고 있다. 그 중, 슬릿트형 사방댐은 환경훼손을 최소화하기때문에 많이 사용되고 있는 추세이다. 그러나, 슬릿트형 사방댐의 배치에 따른 효율성에 관한 연구는 아직 미비한 상황이다. 본 연구에서는 슬릿트형 사방댐의 배치형태가 토석류 흐름에 미치는 영향을 토석류의 속도 감소와 포착율을 통해 분석하였다. 축소된 실내모형실험을 통해 토석류의 속도 변화와 포착율을 측정하였고, 이를 토대로 슬릿트형 사방댐의 성능 평가를 하였다. 축소모형 실험 결과는슬릿트형 사방댐 사이의 간격과 배치 각도가 슬릿트형 사방댐의 성능에 큰 영향을 주는 것으로 나타났다. Debris flows caused by heavy rainfall occur along long watersheds and travel at extremely rapid velocity. This phenomenon involves fast moving fluids induced by gravity and causes economic and societal damages when debris flows overflow to urban area. For this reason, barriers against debris flows have been widely employed. In particular, slit-type barriers are popularly used because of the minimum disturbance to surrounding environments. However, the performance of such slit-type barriers is not fully understood. This paper explores roles of spacing and angle of slit-type barriers on velocity reduction and trap ratio of the debris flows. The scaled physical modeling experiments were performed to examine the reduction of debris velocity and trap ratio and to assess the performance of debris flow barriers. The results indicate that the performance of barriers is heavily affected by spacing between slit-type barriers and angle of barriers from flow direction.

터널 및 지중매설물 시공에 따른 지반함몰 발생 원인 및 대책에 대한 지반공학적 조사 연구

최신규,백승훈,안준범,권태혁,Choi, Shin-Kyu,Back, Seung-Hun,An, Jun-Beom,Kwon, Tae-Hyuk 한국터널지하공간학회 2016 한국터널지하공간학회논문집 Vol.18 No.2

최근 국내 빈번하게 발생되고 있는 지반함몰 현상의 원인, 현황, 대책에 대하여 지반공학적인 접근 방법으로 조사하였다. 국내 발생된 지반함몰은 대부분 터널 굴착 공사와 지중매설관의 손상에 의한 것으로 나타났다. 용산역과 석촌 지하차도 지반함몰 사례와 같이, 굴착 공사 중 지반함몰은 지하수와 토사의 과다 유출이 주된 원인으로 나타났다. 특히, 충적층과 같은 연약지반에서의 기계식 굴착 시, TBM 굴착이 멈춘 지점에서 지반함몰 위험이 큰 것으로 나타났다. 서울시에서 발생된 지중매설관 손상으로 인한 지반함몰 사고를 종합하였을 때, 시공 시의 부주의, 노후화, 연약지반에서의 관의 부등침하 등이 지반함몰의 원인으로 나타났다. 터널 굴착 공사에 의한 지반함몰은 공사 시 발생되는 지하수, 토사의 이동에 대한 모니터링을 통해 대비할 수 있다. 지중매설관 손상으로 인한 지반함몰은 지중매설관의 생애주기 분석 및 유지관리 혹은 관 상부의 토압 분산 및 토압 지지력 증대를 통하여 대비할 수 있을 것으로 판단된다. This study investigated the occurrences, causes, and mitigation of the recent ground subsidence and underground cavity generation events in Korea. Two main causes of ground subsidence are (1) the soil erosion by seepage during tunneling and earth excavation and (2) the damage of underground pipes. The main cause of the soil erosion during tunneling was the uncontrolled groundwater flow. Especially, when excavating soft grounds using a tunnel boring machine (TBM), the ground near TBM operation halt points were found to be the most vulnerable to failure. The damage of underground pipes was mainly caused by poor construction, material deterioration, and differential settlement in soft soils. The ground subsidence during tunneling and earth excavation can be managed by monitoring the outflow of groundwater and eroded soils in construction sites. It is expected that the ground subsidence by the underground pipe damage can be managed or mitigated by life cycle analysis and maintenance of the buried pipes, and by controlling the earth pressure distribution or increasing the bearing capacity at the upper ground of the buried pipes.

무인항공기를 이용한 산사태 분석용 데이터 획득 기법 개발

최신규,권태혁 한국지반신소재학회 2021 한국지반신소재학회지 Vol.20 No.3

폐경기 여성에서 여성 호르몬 대체요법이 요추 및 대퇴골 골밀도에 미치는 영향

최신규,윤주혜,김응수,오장균 대한가정의학회 1998 Korean Journal of Family Medicine Vol.19 No.1

Contradictory Effects of Superoxide and Hydrogen Peroxide on KCa3.1 in Human Endothelial Cells

최신규,나혜영,김지애,조성은,서석효 대한약리학회 2013 The Korean Journal of Physiology & Pharmacology Vol.17 No.3

Reactive oxygen species (ROS) are generated in various cells, including vascular smooth muscle and endothelial cells, and regulate ion channel functions. KCa3.1 plays an important role in endothelial functions. However, the effects of superoxide and hydrogen peroxide radicals on the expression of this ion channel in the endothelium remain unclear. In this study, we examined the effects of ROS donors on KCa3.1 expression and the K+ current in primary cultured human umbilical vein endothelial cells (HUVECs). The hydrogen peroxide donor, tert-butyl hydroperoxide (TBHP), upregulated KCa3.1 expression,while the superoxide donors, xanthine/xanthine oxidase mixture (X/XO) and lysophosphatidylcholine (LPC), downregulated its expression, in a concentration-dependent manner. These ROS donor effects were prevented by antioxidants or superoxide dismustase. Phosphorylated extracellular signal-regulated kinase (pERK) was upregulated by TBHP and downregulated by X/XO. In addition, repressor element-1-silencing transcription factor (REST) was downregulated by TBHP, and upregulated by X/XO. Furthermore, KCa3.1 current, which was activated by clamping cells with 1 μM Ca2+ and applying the KCa3.1 activator 1-ethyl-2-benzimidazolinone, was further augmented by TBHP,and inhibited by X/XO. These effects were prevented by antioxidants. The results suggest that hydrogen peroxide increases KCa3.1 expression by upregulating pERK and downregulating REST, and augments the K+ current. On the other hand, superoxide reduces KCa3.1 expression by downregulating pERK and upregulating REST, and inhibits the K+ current. ROS thereby play a key role in both physiological and pathological processes in endothelial cells by regulating KCa3.1 and endothelial function.

무인항공기-라이다를 이용한 산사태 분석을 위한 데이터 획득 및 해석 기법 연구

최신규(Choi, Shin-Kyu),Ryan Ramirez,노동화(Noh, Dong-Hwa),이승래(Lee, Seung-Rae),김윤태(Kim, Yun-Tae),권태혁(Kwon, Tae-Hyuk) 대한토목학회 2020 대한토목학회 학술대회 Vol.2020 No.10

사춘기전 치주염 치료시 공제영상 측정법 이용에 대한 증례보고

최신규,이광희 大韓小兒齒科學會 1993 大韓小兒齒科學會誌 Vol.20 No.2

Subtraction technique has increased detectability of small osseous changes compared with conventional radiograph. We used subtraction technique in analysis and evaluation of the bone density change before and after the treatment of prepubertal periodontitis in an eleven-year-old female patient. The patient was examined clinically, hematologically and radiologically. Clinical examination showed periodontal abscess in maxillary right second premolar and first molar area and gingival swelling in maxillary left premolar area. The result of hematological analysis was within normal limit. Radiological examination showed vertical bone resorption at maxillary right first premolar and first molar and also periapical lesion at maxillary right premolar. The patient was treated by subgingival curettage, endodontic treatment and reconstructive osseous surgery. Hydroxyapatite was filled in mesial and distal area of maxillary right first premolar and mesial area of maxillary first molar. In radiographic view at 6 months after operation, normal bony trabecular pattern was observed in the defect area which was embedded by HA. Apical lesion disappeared and lamina dura has a normal pattern. Daily mechanical removal of plaque by patient was emphasized for the success of treatment. This study revealed that the subtraction technique increased the accuracy of radiograph reading in the treatment of periodontitis.

사방댐 설치에 따른 토석류 흐름에 대한 영향

최신규(Choi Shin Kyu),권태혁(Kwon Tae Hyuk) 한국방재학회 2017 한국방재학회논문집 Vol.17 No.6

집중호우에 의해 발생된 토석류는 매우 빠른 속도로 유역을 따라 흐른다. 이러한 토석류는 막대한 재산 및 인명 피해 등의 사회적, 경제적 피해를 일으킨다. 토석류로 인한 피해를 막기 위해 사방댐 건설이 급격히 증가하고 있지만, 사방댐 설치에 따른 토석류 흐름에 미치는 영향에 대한 충분한 이해가 부족한 상황이다. 본 연구에서는 SPH 기반의 토석류 흐름 예측프로그램인 DAN3D를 이용하여 국내 산지에서 사방댐의 배치에 따른 토석류의 속도와 깊이 변화를 분석하였다. 사방댐을 설치한 경우 토석류는 충돌 직후 속도와 너비가 일시적으로 증가하나, 하류부에 도달하였을 때는 사방댐을 설치하지 않은 경우보다 속도와 깊이가 감소하는 경향을 보였다. 연구를 통해 도출된 결과는 사방댐 설계 및 현장적용을 위한 근본적인 자료로 사용될 것이다. Debris flows caused by heavy rainfall occur along long watersheds and travel at extremely rapid velocities. Such debris flows can impact large areas and often cause economic and social damages. In order to prevent the damages, barriers against debris flows have been widely constructed. However, the effect of barriers on debris flow behavior are not fully understood. This paper presents the numerical modeling results of velocity and volume of debris flows against installation of barriers using the smoothed particle hydrodynamics method. Each time that a simulated debris flow collided with the barriers, its area and velocity increased, although those velocities decreased over time compared to the reference case. These results will be used for design and application of barriers as fundamental data.

슬릿형 사방댐의 토석류 포착 특성

최신규(Choi Shin Kyu),이정민(Lee Jung Min),김윤태(Kim Yun Tae),권태혁(Kwon Tae Hyuk) 한국방재학회 2017 한국방재학회논문집 Vol.17 No.5

사방댐은 집중호우 시 토사와 강우가 혼합되어 발생된 토석류로 인한 피해를 막기 위한 대표적인 방법이다. 이런 사방댐의 최적 설계 및 최적 배치를 위해서 축소모형실험과 수치해석을 이용한 연구를 수행하여 왔으나, 현장 규모의 실험을 통한 사방댐의 토석류 방어 성능에 대한 연구는 미비한 상황이다. 본 연구에서는 파일럿 스케일의 약 70 m 길이의 산지 유역에서 사방댐 설치에 따른 토석류 포착 특성을 연구하였다. 대상 산지 유역에 슬릿형 사방댐, 개비온 사방댐과 모니터링 시스템을 설치한 후, 2016년 7월 4일 오전 국지성 호우에 의해 다량의 물과 토사가 유역을 따라 발생되었다. 실시간 현장 계측 결과, 사후 현장 조사, 입도 분포 분석을 통해 토석류 발생 시점과 사방댐의 토석류 포착 특성을 분석하였다. 중류부에 슬릿형 사방댐은 슬릿의 너비(w = 28 cm)의 0.36 w인 10 cm 크기 자갈부터 최대 지름이 약 18 cm(0.65 w)인 자갈이 주로 포착되었고, 하류부의 불투과형 사방댐은 크기가 작은 모래를 포착하는 것으로 나타났다. Barriers are widely installed as active measures to prevent damages that can be caused by debris flows. Small-scale experiments and numerical modeling have been used to evaluate the performance of the barriers against debris flows; however, field-scale experiments have been rarely conducted. We investigated the effect of slit-type barriers on the characteristics of trapped debris through the pilot-scale application at a ~ 70 m long channel in a mountain valley. The slit- and gabion-type barriers and monitoring sensors were installed along the channel, and large amounts of water and soil debris flowed downstream in July 4th, 2016. The trapping of debris by barriers was examined by using the real-time field monitoring data, site investigation, and sieve analysis. It revealed that our slit-type barrier, of which slit width (w) was 28 cm, mostly trapped the gravels and cobbles of ~10-18 cm (0.36-0.65 w) in size. The finer soil particles were trapped by the closed-type barrier in the downstream.