혈액 투석 환자에서 중심정맥 협착에 대한 스텐트 삽입술 : Wallstent Placement

임대승,노상필,이유선,정승현,김보영,이정우,강정아,김정희,이민수,정준용,최시완,정진옥,성인환,이강욱,신영태 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

Stenosis of central vein is a common complication arising after percutaneous subclavian vein catheter insertion performed for temporary vascular access in chronic renal failure patients undergoing hemodialysis. There are several treatment methods for the condition like percutaneous angioplasty(PTA), stent insertion, and surgery, but recent trend is toward PTA and stents. Among the patients diagnosed with chronic renal failure from March 1993 to May 2002 and undergoing hemodialysis through AV fistula, the 14 Patients in whom central vein stenosis arose were selected for the study. A total of 28 percutaneous interventions(5 PTA and 23 stent placement) were performed, and restenosis rate and the time taken till the restenosis in de novo lesions and instant lesions were compared. All 28 cases were operated successfully. The 14 cases that received both anigioplasty and stent placement initially. (de novo lesion : 14 cases), Among the 10 cases with de novo lesion that followed up more than 1 year, 3 cases are currently undergoing hemodialysis without restenosis, and the remaining 7 cases have recurred stenosis with the mean time to restenosis of 10.9 months. In the 7 cases in whom stenosis recurred, 11 interventions were done(instent lesion: 11 cases). 4 of these were using only ballon angioplasty with 100% restenosis rate and the mean time of 3 months until restenosis. The remaining 7 cases were using both balloon angioplasty and stent placement, also with 100% restenosis rate but with the mean time of 12 months until restenosis, which was later than the group receiving only balloon angioplasty. In treating the patients with central vein stenosis, stent placement seems to be more advantageous over PTA in terms of restenosis rate and the mean duration of patency. In the case of instent lesion, inserting the stent for the second time after stenosis recurred lengthened the duration of patency compared to performing balloon angioplasty alone.

백서의 실험적 치아이동시 connexin 43의 발현에 관한 연구

임정현,김은철,김상철 원광대학교 생체재료·매식연구소 1998 원광생체재료·매식 Vol.7 No.1

Bone remodeling in response to force requires coordinated actions of osteoblasts, osteoclasts, osteocytes, and periodontal ligament cells. Coordination among these cells may be mediated, in part, by cell-to-cell communication via gap junctions. This study was designed to evaluate the expression of gap junction, connection 43 in periodontal tissue during the experimental movement of rat's incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for connexin 43. Twently seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental group(24 rats) where 75g of force was applied from helical springs across the maxillary incisors. Rats of experimental group were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. And the tissues of a control group and experimental groups were studied immunohistochemically. The results were as follows: 1. In control group, the expression of connexin 43 was rare in gingiva, dentin, cementum, periodontal ligament, and bone cells. 2. In experimental group, the expression of connexin 43 was increased in pulp, periodontal ligament, osteoblasts, and osteoclasts, comparing to that in control. And it was rare in gingiva, dentin, and odontoblasts regardless of the duration of force application, which was not different form that of control group. 3. The expression of connexin 43 in pulp of experimental group began to increase in 4-day after force application and got to the highest degree at 7-day. And it decreased after 14-day to be similar to that of control group at 28-day. 4. The expression of connexin 43 in periodontal ligament was noted in small capillaries adjacent to alveolar bone, showing higher intensity of immunolabelling after 4-day. And it was stronger in the pressure side than in tension side of periodontal ligament. After 7-day, decrease in connexin 43 expression was observed. 5. The expression of connexin 43 in alveolar bone began to increase 1-day, reached to the highest degree at 4-day, and decreased at 7-day. And the expression in osteoclasts was more than that in osteoblasts or osteocyte at 7-day.

Effect of Photoperiod, Temperature and True-leaf Stage in Bolting Rate of Chicory (Cichorium intybus L. var. sativus)

Lim,Jung-Dae,Seo,Jeong-Sik,Lee,Hyeon-Yong,Kim,Jong-Dai,Lee,Jin-Ha,Yu,Chang-Yeon 한국자원식물학회 2004 Plant Resources Vol.7 No.1

Root chicory (Cichorium intybus L. var. sativus) is potential alternative medicinal and sugar crop which accumulates a high amount of linear polyfructan, inulin in its roots. A problem in root production is that over-wintered stock plants often flower. Once the plant becomes reproductive, stem elongation and root growth slows and floral buds arise from every node, rendering the plants useless for propagation. The objectives of this research was to examine the effectiveness of manipulating environmental factors containing photoperiod, temperature and number of leaf states. The experiment was performed in growth chamber to create two photoperiods (8 h, and 16 h) with three temperature regimes (5℃/3℃, 10℃/8℃, and 15℃/13℃ day/night temperature) for a total of six treatments on three type of true-leaf stage of plant. Data of bolting rate, shoot and root length, shoot and fresh weight was invetigated in each treatments. This is the first report on changes in bolting rate and shoots and roots production during a whole growing season and differences in the effect of cold and photoperiod treatment depending on the true-leaf stage of plant.

교정용 선재의 TORQUE 효과에 관한 연구

임정현,김상철 대한치과교정학회 1994 대한치과교정학회지 Vol.24 No.1

The purpose of this study was to evaluate the torque effect of orthodontic wires. Ten types of orthodontic wires (five types of materials, two types of cross-sectional dimensions) were selected. Each group of wire type was constituted with five specimens. These specimens were tested on the universal testing machine(Instron) with specially-designed jig. The torque-twist curve of each wire was obtained and the results were analyzed statistically. The results were as follows : 1. 0.017" X 0.025" wire showed more torque effect than 0.016" X 0.022" wire at the same twist. 2. Torque effect was the greatest in stainless steel and the least in Nitinol. 3. The maximum amount of torque was the greatest in heat-treated Blue Elgiloy and the least in Nitinol.

초등학교장의 변혁적 지도성과 교사 효능감과의 관계

임종철,김현정 부산교육대학교 교육대학원 2004 논문집 Vol.6 No.-

이 연구에서는 초등학교장의 변혁적 지도성과 교사 효능감과의 관계를 규명하고자 하였다. 문헌연구를 통해 지도성의 개념과 변천과정 학교장의 변혁적 지도성 이론, 교사 효능감에 대한 이론을 살펴 보았으며, 이러한 배경 이론에 근거하여 학교장의 변혁적 지도성의 하위요인으로 결속촉진, 카리스마, 지적인 자극, 개별적 관심을, 교사 효능감의 하위요인으로 자신감, 자기조절 효능감, 과제난이도 선호를 파악하였다. 그리고 선행연구를 통해서 두 변인의 관계를 고찰해 보았다. 문헌연구를 토대로 연구문제를 해결하기 위하여 부산시내 36개 초등학교 교사를 대상으로 학교장의 변혁적 지도성 및 교사 효능감 질문지로 측정하여 상관관계를 살펴본 결과 교사가 인식한 학교장의 변혁적 지도성 수준은 보통 수준 이상(M=3.30)으로 나타났으며, 하위요인별로는 다른 요인에 비해 지적인 자극을 많이 인식하고 있는 것으로 나타났다. 교사의 교사 효능감 수준도 보통 수준 이상(M=3.29)으로 나타났으며 하위요인별로는 다른 요인에 비해 자기조절 효능감을 보다 많이 지각하고 있는 것으로 나타났다. 학교장의 변혁적 지도성과 교사 효능감의 상관관계는 r=.294(p<.001)로 유의한 상관이 있기는 하나 얕은 것으로 나타났으며, 하위요인간의 상관관계에서는 학교장의 변혁적 지도성의 하위요인인 결속촉진, 카리스마, 지적인 자극, 개별적 배려가 교사 효능감의 하위요인인 자기조절 효능감과 유의한 상관이 있기는 하나 얕고, 자신감, 과제난이도 선호와는 상관이 거의 없는 것으로 나타났다. The purpose of this study was to find out the relationship between the elementary school principals' transformational leadership and the teacher efficacy. To achieve this goal, several research problems were established as follows: First, what is the elementary school principals' transformational leadership (contribution to cohesion, charisma, intellectual stimulation and individual concern)? Second, what is the teacher efficacy(confidence, self-control and preference for task difficulty)? Third, what is the relationship between the elementary school principals' transformational leadership and the teacher efficacy? To solve these problems, both the literature research and questionnaire surveys were used in this study. Through the literature research, the concept of leadership and the process of its change was examined, and theory of the school principals' transformational leadership and its background of formation, the concept and the specific character of the transformational leadership, the primary factors and the effects of the transformational leadership were examined. And then it's attempted to find out contribution to cohesion, charisma, intellectual stimulation and concern for individual teachers, which were subordinate factors of principal transformational leadership. Concerning the teacher efficacy, self-efficacy, the concept of the teacher efficacy, the features of teachers with good the teacher efficacy and the elements of the teacher efficacy were examined. As for the teacher efficacy subordinate factors, teacher confidence, self-control efficacy and preference for task difficulty were investigated. Finally, earlier studies were reviewed to identify the relationship of the two factors. Based on the results of literature research and to solve the research problems, 36 elementary schools and 524 teachers of the schools in Busan Metropolitan City were selected randomly. The instruments used in this study were Gweon In-tak's transformational leadership questionnaire and Lee Hyeon-jeong's the teacher efficacy questionnaire. As for reliability, the former's Cronbach α coefficient was .98, and the latter's was .85. The collected data were analyzed with SPSSWIN Ver 10.07 program. The statistical data on mean and standard deviation were obtained, and t-test and F-test were conducted. In case there was any intergroup gap, Scheffe´ test was implemented as post-test, and the correlation between the two factors was measured by calculating Pearson'r. The findings of this study were as follows: First, the teachers considered their principals' transformational leadership to be on the average(M=3.30). By subordinate factors, intellectual stimulation were rated better than the others. Second, as for the impact of their background variables on their perception of principal transformational leadership, the principals were thought to exercise more transformational leadership by those who were lead teachers, had more than career of 20 years, in their 40s and worked at the schools of C and D grade. And they felt that the female principals displayed transformational leadership more than the male principals did. Third, the teacher efficacy is to be on the average (M=3.29). By subordinate factors, they put higher value on self-control efficacy than on the other factors. Fourth, as for the impact of their background variables on their the teacher efficacy, those who were male, lead teachers, had more than career of 20 years, in their 40s, and whose principals were male, viewed the teacher efficacy more favorably. Fifth, there was significant but weak correlation between the transformational leadership of their principals and their self-efficacy (r=.294, p<.001). By subordinate factors, contribution to cohesion, charisma, intellectual stimulation and individual concern had significant yet weak correlation to self-control efficacy, and they were scarcely correlated to confidence and preference for task difficulty. Based on the above-mentioned findings, the following conclusion was reached: First, how principals could be encouraged to exert more transformational leadership should be studied, and a variety of programs should be prepared to boost the transformational leadership of male principals. Second, in which way the teacher efficacy could improve should be considered. Especially, it's necessary to instill more confidence in teachers and urge them to make a challenge to difficult tasks. Third, as principal transformational leadership had weak yet significant correlation to the teacher efficacy, the former factor can predict the latter to some extent. Fourth, since questionnaire method was utilized in this study, future research should make a qualitative approach by using ethnography

조사기간에 다른 유즙 섭취 측정치의 비교

임현숙,이정아 全南大學校家政科學硏究所 1995 生活科學硏究 Vol.5 No.-

This study was conducted to evaluate the validity of lactational performance parameters according to the periods of measurement. The subjects enrolled were 10 breast-fed and 20 formula-fed infants. Ingested volumes of milk per day and per feeding and feeding frequency per day of the infants were measured for 24, 48 and 72 hours, respectively at 1, 2 and 3 months age. For breast-fed infants, ingested volume of milk was estimated by test-weighing method and that for formula-fed infants was tested by direct measurement method. There were no significant differences among the values of ingested milk volume per day and per feeding obtained by 24-, 48- and 72-hour measurement at all 1, 2 and 3 months age in breast-fed as well as formula-fed infants. Also, there were no significant differences among the data of feeding frequency per day obtained by 3 different periods of measurement except for the data estimated in breast-fed infants at 3 months age. The results of this study indicate that the values of lactational performance parameters obtained for 24-hour measurement are valid.

백서의 실험적 치아이동시 connexin 43의 발현에 관한 연구

임정현,강경화,이종진,김은철,김상철 대한치과교정학회 2001 대한치과교정학회지 Vol.31 No.5

치아이동시 골세포간 활성 조화에서 세포간 교통의 중요성이 차츰 인식되고 있으며 세포간 교통을 위한 교통반의 존재가 확인되고 있다. 동물실험 모델에서 실험적 치아이동을 통해 조성된 압박 및 견인측 치주인대에서 교통반 단백의 일종인 connexin 43의 발현을 관찰함으로써 인접 연조직 및 골 조직 내에서 세포 신호 전달 양상의 한 부분을 파악하고자 하였다. Sprague-Dawley계 백서 27마리를 대조군(3마리)과 실험군(24마리)으로 나누었으며, 실험군은 견인력(75g)을 가한 후 12시간, 1일, 4일, 7일, 14일, 28일이 경과한 후 각각 4마리씩 희생시켜, connexin 43의 발현을 면역조직화학적으로 관찰한 바 다음과 같은 결과를 얻었다. 1.대조군에서의 connexin 43 발현은 치은, 상아질, 치주인대, 치수, 골세포에서 경미하였다. 2.교정적 치아이동에 반응하는 치수, 치주인대, 골모세포, 파골세포, 골세포부위에서 connexin 43의 발현이 많았으나 치은, 상아질, 상아모세포에서의 발현은 견인력 적용기간에 관계없이 대조군과 큰 차이가 없었다. 3.치수에서 connexin 43의 발현은 교정력을 가한 4일에서부터 증가하여 7일째까지 크게 증가한 후 14일째부터 감소되었으며 28일째에는 대조군과 차이가 없었다. 4.치주인대에서 connexin 43의 발현은 주로 혈관을 중심으로 치조골 면을 따라 압박측에서 주로 나타났는데 교정력을 가한 12시간에서부터 증가하여 4일에서 가장 많은 발현을 보인 후 7일부터 감소하기 시작하였다. 5.골모세포 및 골세포에서 발현은 실험 1일째부터 출현해 4일째에 가장 많은 발현을 보였고 7일 이후에는 크게 감소하였으며 파골세포에서의 발현은 골모세포와 골세포보다 실험 4일째에 더 많이 관찰할 수 있었다. Bone remodeling in response to force requires coordinated actions of osteoblasts, osteoclasts, osteocytes, and periodontal ligament cells. Coordination among these cells may be mediated, in part, by cell-to-cell communication via gap junctions. This study was designed to evaluate the expression of gap junction, connection 43 in periodontal tissue during the experimental movement of rat's incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining fort connexin 43. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental groups(24 rats) where 75g of force was applied from helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. And the tissues of a control group and experimental groups were studied immunohistochemically. The results were as follows : 1.In control group, the expression of connexin 43 was rare in gingiva, dentin, cementum, periodontal ligament and bone cells. 2.In experimental group, the expression of connexin 43 was increased in pulp, periodontal ligament, osteoblasts, and osteoclasts, comparing to that in control. And it was rare in gingiva, dentin, and odontoblasts regardless of the duration of force application, which was not different from that of control group. 3.The expression of connexin 43 in pulp of experimental group began to increase in 4-day after force application and got to the highest degree at 7-day. And it decreased after 14-day to be similar to that of control group at 28-day. 4.The expression of connexin 43 in periodontal ligament was noted in small capillaries adjacent to alveolar bone, showing higher intensity of immunolabelling after 4-day. And it was stronger in the pressure side than in tension side of periodontal ligament. After 7-day, decrease in connexin 43 expression was observed. 5.The expression of connexin 43 in alveolar bone began to increase 1-day, reached to the highest degree at 4-day, and decreased at 7-day. And the expression in osteoclasts was more than that in osteoblasts or osteocyte at 7-day.

STRESS DISTRIBUTION OF ENDODONTICALLY TREATED MAXILLARY SECOND PREMOLARS RESTORED WITH DIFFERENT METHODS : THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS

임동열,김현철,허복,김광훈,손권,박정길 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.1

본 연구의 목적은 근관치료 된 치아를 구조와 물성이 다른 post와 core 그리고 전장관으로 수복한 후 과도한 교합하중을 가했을 때 치아에 나타나는 응력분포를 조사하기 위함이다. 발치 된 상악 제2소구치를 micro-CT로 단층촬영하고 3D Doctor로 윤곽선을 추출한 다음 HyperMesh Ver. 6으로 삼차원 치아모형을 만들고 다음과 같은 세 가지 방볍으로 수복한 유한요소모형을 제작하였다. 1) 스테인레스 스틸 포스트와 복합레진 코어 그리고 도재소부전장금관으로 수복한 모형 2) fiber 포스트와 복합레전 코어 그리고 전부도재관으로 수복한 모형 . 3)포스트, 코어와 전장관이 일체형인 간접복합레진 EndoCrown으로 수복한 모형. 형성된 모형의 협측 또는 설측교두에 500N의 하중을 가하였으며 하중의 방향은 치아 장축에 대해 45도 이었다. 치관부와 치근부의 von Mises 응력을 ANSYS 9.0 프로그램으로 분석한 결과 포스트와 코어의 형태보다는 전장관 재료의 탄성계수가 근관치료된 상악 소구치의 응력분포를 좌우하였다. 치관부에서는 재료의 탄성계수가 높은 전장관으로 수복한 모형이 낮은 응력분포를 보였다. 치근부에서는 재료의 탄성계수가 낮은 전장관으로 수복한 모형이 낮은 응력분포를 보였다 The purpose of this study was to evaluate the influence of elastic modulus of restorative materials and the number of interfaces of post and core systems on the stress distribution of three differently restored endodontically treatcd maxillary second premolars using 3D FE analysis Model 1, 2 was restored with a stainless steel or glass fiber post and direct composite resin. A PFG or a sintered alumina crown was considered. Model 3 was restored by EndoCrown. An obliquc 500 N was applied on thc buccal (Load A) and palatal (Load B) cusp. The von Mises stresses in the coronal and root structure of each model were analyzed using ANSYS. The elastic modulus of the definitive restorations rather than the type of post and core system was thc primary factor that influenced the stress distribution of endodontically treated maxillary premolars. The stress concentration at thc coronal structure could be lowered through the use of definitive restoration of high elastic modulus The stress concentration at the root structure could be lowered through the use of definitive restoration of low elastic modulus.

S.D. Rats를 이용 1, 1-Dichloro-1-fluoroethane의 아민성 흡입독성 연구

김현영,이성배,임철홍,김철우,점용현,한정희,전윤석,최수영,강대봉,이용묵 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.1

There were no specific effects for test materials on Sprague-Dawley (S.D.) rats in clinical symptoms, amounts of food intakes, weight changes, laboratory findings, and pathology after whole body l, l-Dichloro-1 -fluoroethane (used as coolant, metal cleaner and solvents) exposure(0, 1,500, 3,000, and 6,000 ppm) for 13 weeks (6 hour/day, 5 days/week). However, the loss of capillary vessels in eyeball (pupil) was observed in a female rat among 6,000 ppm group. Though there was a tendency for MCHC (Mean Corpuscular Hemoglobin Concentration) in rat to be decreased (p<0.05), it was not regarded as abnormal because the values were within normal limits. In asthma-stimulation related evaluations, there was also a tendency for inflammatory cell counts in bronchoalveolar lavages to be increased. But it had no statistical significance, and also no dependency on sex and the exposed concentration. Based on this result, the non observed effect level (NOEL) induced by 1, 1-Dichloro-l -fluoroethene inhalation was evaluated in groups with 3,000 ppm below (S .D. Rats, 13 weeks). Finally, it was concluded that the short term exposal of 1, 1-Dichloro-l-fluoroethane is not considered as a asthma stimulant by inhalation despite of some study limitations such as test animals use and short-term exposure .

모조 근관의 크기와 충전 방법이 orthograde MTA apical plug의 미세누출에 미치는 영향

남득림,박정길,허복,김현철 大韓齒科保存學會 2009 Restorative Dentistry & Endodontics Vol.34 No.3

The purpose of this study was to compare the dye leakage of MTA (mineral trioxide aggregate) apical plug produced by two orthograde placement techniques (hand condensation technique and ultrasonically assisted hand condensation technique). To simulate straight canal, 60 transparent acrylic blocks with straight canal were fabricated. These transparent acrylic blocks were divided into 2 groups (Group C: hand condensation technique (HC) and Group U; ultrasonically assisted hand condensation technique(UAHC)) of 30 blocks with each MTA application method. Each group was divided into 2 subgroups (n = 15) with different canal size of #70 (subgroup C70 and subgroup U70) and #120 (subgroup C120 and subgroup U120). After apical plug was created, a wet paper point was placed over the MTA plug and specimen was kept in a humid condition at room temperature to allow MTA to set. After 24 hours, remaining canal space was backfilled using ObturaⅡ. All specimens were transferred to floral form socked by 0.2% rhodamine B solution and stored in 100% humidity at room temperature. After 48 hours, resin block specimens were washed and scanned using a scanner. The maximum length of microleakage was measured from the scanned images of four surfaces of each resin block using Photoshop 6.0. Statistical analysis was performed with Mann-Whitney U test. Group U of UAHC had significantly lower leakage than Group C of HC in #70-size canal (subgroup U70) (p<0.05). 이 연구의 목적은 서로 다른 두 개의 근관 크기(#70, #120)를 가진 레진 모형에 MTA (mineral trioxide aggregate)를 서로 다른 두 가지 방법 (수기구 충전(HC), 초음파 보조 수기구 충전(UAHC))으로 정방위 충전하고 MTA apical plug의 미세누출을 평가하는 것이다. 직선형 근관 형태를 가지며, #70과 #120의 치근단 크기를 갖는 레진 모형을 각각 30개씩 준비하였다. 이 시편들을 MTA의 적용 방법에 따라 각 군을 2개의 아군으로 다음과 같이 분류하였다 (n=15); C70: HC + 치근단 크기 #70, C120: HC + 치근단 크기 #120, U70: UAHC + 치근단 크기 #70, U120: UAHC + 치근단크기 #120. MTA충전을 완료한 후에, 24시간 동안 실온에서 100% 습도를 유지하여 경화시켰다. 근관의 상부는 열연화 충전 시스템(Obtura Ⅱ)을 이용하여 충전하였다. 48시간 동안 100% 습도를 유지하여 실온에서 0.2% rhodamine B 용액을 이용해 미세누출 실험을 하였다. 이 연구결과 #70의 치근단 크기를 갖는 그룹 사이에서 UAHC가 HC에 비해 미세누출이 적은 것으로 나타났다(p<0.05). 이 연구 조건하에서는 초음파 진동을 동반한 정방위 MTA apical plug 형성 방법이, 특히 좁은 근관에서 더 효율적 인 것으로 사료된다.