제2형 근관의 확대에 따른 최종근관장파일 크기의 비교

정은주,이동균,백신영,황호길 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.5

제2형의 근관형태를 갖는 치아에서 각각의 근관을 모두 근관장까지 확대한 경우,여러 확대기구에 따른 최종근관장파일의 크기를 상호 비교하여 얼마나 많은 변화가 있었는지를 분석하고자 치근 우식이 없고 치근단공 형성이 완료되었으며 2개의 근관 입구에서 시작하여 하나의 치근단공을 갖는 제 2형의 근관형태를 보이는 상악 소구치,상악 대구치의 근심협측 치근 및 하악 대구치의 근심 치근을 선택하여 확대기구에 따라 KF 군, PT 군,HS 군, K3 군으로 분류하고 치경부 조기 확대를 시행하였다. 초기근관장파일이 15번 크기인 지아를 각 군당 20개씩 무작위로 선택하였고,모든 근관을 각 군에 해당되는 30번 크기의 파일까지 제조회사의 지시에 따라 확대를 시행한 후,촉감과 universal testing machine을 이용하여 최종근관장파일의 크기를 결정하였다. 각 군의 최종근관장파일의 크기와 제거 시 요구되는 힘의 크기에 대한 유의성 검증은 one-way ANOVA를 이용하여 비교 분석하였으며,사후검정은 Tukey HSD test를 이용하여 0.05의 유의수준에서 분석하였다. 본 연구의 결과 제2형의 근관형태를 갖는 치아의 근관확대 시,모든 근관을 각각의 근관장으로 확대하는 방법은 확대에 마지막으로 이용된 기구의 크기보다 한,두 단계 정도 증가된 최종근관장파일을 나타냈다. 그러므로 제2형 근관형태를 나타내는 치아의 근관치료 시 임상가들은 근관충전에 앞서 치근단 받침을 다시 확인하고 형성하는 과정이 필요하리라 사료된다. Type II root canal was defined that two canals leave the chamber and merge to form a single canal at short of the apex. The aim of this study was to analyse the master apical file (MAF) size according to various instrumentation techniques in the type II root canal when each canal was enlarged to working length. Eighty mesial roots of molar with ISO #15 initial apical file (IAF) size in type II root canals were randomly divided into four experimental groups with 20 teeth each. According to enlarging instruments, four groups are: K-FLEXOFILE^(?) (KF), engine-driven Ni-Ti PRoT_(APER)^(?)(PT), HERO Shaper^(?)(HS), K³™ (K3). All canals were enlarged to each working length with ISO #30 size: #30 in KF, F3 in PT, .04/30 in HS, and .06/30 in K3. The master apical file (MAF) size was confirmed by tactile sensation and universal testing machine (EZ test, Shimadzu Co., Kyoto, Japan). The mean MAF size was statistically compared using one-way ANOVA and Tukey HSD test at the 0.05 probability level. These results show that the MAF size was appeared one or two sizes larger than the final enlarging instrument when all canal in type II configuration were enlarged to each working length. Therefore, the clinician have to confirm the apical stop once more after instrumentation of type II root canal.

Sn-xAg-0.5Cu 무연 솔더 볼의 파단특성 연구

정종설,이용성,신기훈,정성균,장동영 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

This paper presents a study on the failure characteristics of SnAgCu lead-free solder balls. To estimate the effect of Ag, three types of SnAgCu balls are first prepared by varying the weight percent of Ag (1.0, 3.0, 4.0 wt%) and then analyzed by reliability tests such as thermal shock, high speed ball shear, and drop tests. Thermal shock test reveals that the higher the weight percent of Ag is, the longer the fatigue life becomes. To the contrary, high speed ball-shear test and drop test show that the shear strength and the fracture toughness of solder balls are inversely proportional to the weight percent of Ag, respectively. Reasons for these observations will be further investigated in the future work.

蜂毒藥鍼이 脊髓內 痛症關聯 神經細胞의 活性에 미치는 影響

鄭善喜,李栽東,高炯均,安秉哲,崔道永,朴東錫 경희대학교 동서의학연구소 2001 東西醫學硏究所 論文集 Vol.2000 No.-

In spite of the use of Bee Venom aqua-acupuncture in the clinics, the scientific evaluation of effects is not enough. Bee Venom aqua-acupuncture is used according to the stimulation of acupuncture point and the chemical effects of Bee Venom. The aims of this study is to investigate the analgegic effects of the Bee Venom aqua-acupuncture, through the change of writhing reflex and the change of c-fos in secondary neurons in the spinal cord. Materials and Methods : Pain animal model was used acetic acid method. The changes of writhing reflex of the mice which were derived pain by injecting acetic acid into the abdomen, after stimulating Bee Venom aqua-acupuncture on Chungwan(CV12) were measured. We used Fos immunohistochemical technique to study the neuronal activity in the spinal cord. Results : 1.Expression of c-fos in superficial dosal horn(SDH), nucleus proprius(NP) and neck of dorsal horn(N) on 6~9th thoracic spine decreased significantly at 2.5×10-4g/kg Bee Venom aqua-acupuncture, compared with saline-acetic acid group. 2.The numeral change of Fos-LI neurons on the NP, N, and ventral gray(V) on 6~9th thoracic spine, SDH on 9~11th thoracic spine, and SDH and V on 11~13th thoracic spine decreased significantly at Chungwan(CV12) Bee Venom aqua-acupuncture, compared with saline-acetic acid group. 3.The correlation between the numbers of writhing reflex and Fos-LI neurons in T6-13 segment was statistically statistically significant at Chungwan(CV12) Bee Venom aqua-acupuncture. Conclusion : This study shows that the Bee Venom aqua-acupuncture on Chungwan(CV12) decreases the numbers of Fos-LI neurons. As the analgegic effects of Bee Venom aqua-acupuncture is recognized. Bee Venom aqua-acupuncture treatment is expected for pain modulation. In order to use it in many ways. more researches are needed for the dose and stability of Bee Venom aqua-acupuncture.

급성 림프구성 백혈병 환자에서 아스페르길루스 감염을 동반한 호중구감소성 소장결장염에 의한 작은창자 천공

강동백,임태수,박원철,윤기중,이정균 圓光大學校 醫科學硏究所 2008 圓光醫科學 Vol.23 No.2

저자들은 급성 림프구성 백혈병 치료 도중 아스페르길루스 감염을 동반한 호중구감소성 소장결장염에 의한 작은창자 천공을 경험하였다. 급성 림프구성 백혈병의 항암화학치료 중 발생 할 수 있는 호중구감소성 소장결장염은 다양한 위장관 증상을 보일 수 있으며, 이에 대한 발생 가능성을 고려하여 적극적인 조 기진단과 이에 대한 적극적 치료가 필요하며, 면역기능의 저하로 아스페르길루스 등의 진균 감염이 발생할 수 있으므로 호중구감소성 소장결장염의 치료에 증상의 호전이 없을 때 항진균제를 포함한 광범위한 치료가 고려되어야 한다. Though advancesin imumosuppressive therapy or chemotherapy which have lead to increased survival of leukemia and transplant patient, but the risk of infectious complication has been increasing. Neutropenic enterocolitis is a life threatening complication of chemotherapy for malignancies such as leukemia or lymphoma. Symptoms of neutropenic enterocolitis are nonspecific and it may rapidly lead to intestinal peforation. Aspergilus infection could involve the gastrointestinal tract as a result of neutropenia and mucosal injury after imumosuppressive therapy, chemoetherapy, or antibiotics use, but rarely reported a small bowel perforation combined aspergillus and neutropenic enterocolitis. We present a rare case of ileal perforation caused by neutropenic enterocolitis combined with aspergillus infection during chemotherapy for acute lymphocytic leukemia with a review of the literature.

일부 도시지역 여성의 건강과 가족생활 및 사회생활에 대한 조사

김학균,김정혜,김해연,배철영,신동학 대한가정의학회 1994 Korean Journal of Family Medicine Vol.15 No.6

Soft Agar Assay를 이용한 배양골조직과 골세포의 Transforming Growth Factor-β유리에 관한 연구

백정화,김관식,정동균 대한구강생물학회 1991 International Journal of Oral Biology Vol.15 No.2

To study the effect of PTH, osteotropic hormone, on the TGF-β activity in conditioned medium prepared from bone explants, fetal rat ulnae and radii were removed at 19-day of gestation and organ cultured for 24 hours. Then media were changed with fresh BGJb media for control group or PTH-supplemented media (50 or 200 ng/㎖) for experimental group respectively and conditioned media were prepared by 2-day culture of explants. To study the cellular orgin of matrix-associatied TGF-β and the effect of PTH on the TGF-β activity in conditioned media prepared from bone cells, five bone cell populations were prepared from fetal rat calvaria by sequential enzyme digestion. After primary culture, each bone cell population was collected and resuspended as Ⅰ-Ⅱ, Ⅲ and Ⅳ-Ⅴ groups. After 24 hours, media were changed with fresh minimum essential medium(MEM) or 600 ng/㎖ PTH-supplemented media and conditioned media were prepared by 2-day culture. For activation of latent TGF-β activity in bone cell-conditioned media, media were acidified and then neutralized. TGF-β activities of conditioned media were measured by anchorage-independent growth of NRK fibroblasts using modified Todaro soft agar assay method(1987) and the number of colonies ≥ 50 ㎛ was counted. The observed results were as follows. 1. TGF-β, without 2 ng/㎖ EGF, did not induce colony formation in soft agar suspensions. 2. With 2 ng/㎖ EGF, TGF-β induced NRK cells to form large colonies in soft agar suspensions and colony numbers increased proportionally to TGF-β concentrations from 50 pg/㎖ to 1600 pg/㎖. 3. When ulnae and radii were incubated with 50 ng/㎖ PTH, TGF-β activity in conditioned media was not significantly different from control conditioned media. In contrast, TGF-β activity in conditioned media prepared from culture with supplementation of 200 ng/㎖ PTH, was significantly increased(p < 0.01). 4. TGF-β activity was detectable in all bone cell populations and the amount was not significantly different between cell populations. 5. When bone cell populations were incubated with 600 ng/㎖ PTH. TGF-β activity in conditioned media from each population was not significantly different from control conditioned media. These results suggest that all cell populations isolated from calvaria synthesize TGF-β and PTH has no apparent effects on the TGF-β production of bone cell populations. In addition, increased TGF-β activity in bone explant conditioned media by 200 ng/㎖ PTH appears to be due to the enhanced release of TGF-β from bone matrix secondary to bone resorptive process.

國際 밀 市場의 安定性 分析

최세균,김동민,임정빈 韓國農業政策學會 1992 농업경영정책연구 Vol.19 No.1

강릉 연안에서 어획한 오징어의 간장 중 일반성분 및 지질 조성의 계절변화

조순영,전미정,주동식,전중균,이미희,정인학 강릉대학교동해안지역연구소 1999 東海岸硏究 Vol.10 No.2

연간 어획량으로 볼 때 오징어는 다른 어종 못지않게 중요한 종류이다. 오징어는 몸통뿐 아니라 내장과 간장 또한 이용가치가 매우 뛰어남에도 불구하고 그동안에는 사료용으로만 약간 사용되고 나머지는 대부분 폐기하였다. 본 연구에서는 이들 간장의 이용도를 넓힐수 있는 기초자료를 확보하고자 간장 중 일반성분과 지질 클래스의 변화를 월별로 조사하였다. 우선, 주문진항에서 4월에서 10월까지의 매월 한차례씩 살아있는 오징어를 구입하여 이들의 체중과 체장, 그리고 내장과 간장의 무게를 재고, 간장은 일반성분과 지질분석을 하였는데, 월별 체중 및 체장은 7월을 기점으로 여름철에 증가하며 체중도 같은 경향을 나타내었다. 그리고 간장의 무게도 체중의 증가와 비례하여 증가하였다. 비만도는 체장의 증가율에 비해 체중의 증가율이 높은 5월이 비만도가 가장 높았다. 같은 기간 중 일반성분의 변화를 보면, 수분은 대체로 감소하는 경향이고 단백질은 7월에서 9월 사이에 증가하는 경향을 보였다. 지질은 단백질과는 반대로 7월에서 9월 사이에 감소하는 경향을 보였으며, 회분은 매월 일정한 값을 나타내었다. 이러한 결과로 어체의 성장이 활발한 여름철에 단백질의 양이 증가하고 반면에 지질의 함량은 감소하는 것으로 나타났다. 한편, 지질 클래스에서 단순지질의 경우 NL은 봄철에서 가을로 가면서 점차 증가하는 경향을 보였고, 반면 S, PL은 감소하는 경향을 보였다. PL에서는 대부분 PC만이 검출되었으며, 계절적으로는 봄에서 가을로 갈수록 감소하는 경향을 보였다. Squid is one of the most popular species over the East coast of Korea and sold as raw or processed one at the market. However, the liver and intestine occupied more than 20% of whole body are discarded wastefully at present. At this point of view, we analyzed lipid classes and fatty acid composition of liver, and tried to develop the utilities on the useful components of liver and intestine of squid. Alive squids were collected at the port of Jumunjin, Kangwon-Do, Korea, from April to Oct., 1988, and measured the body length, body weight and liver weight. Chemical composition of liver was analyzed by general method. Moreover, lipid class of total lipid was analysed using Iatroscan. As a results of this study, body weight, body length and liver weight increased after July, and hepatosomatic index(HSI) increased after May. Moreover, condition factor was maintained at moderate level after May. Among chemical components, water content had negative correlation with lipid and concentrations of protein and ash were not changed remarkly. In analysis of lipid class, it was proved that neutral lipid(NL) fraction of total lipid(TL) contained triacylglyceride(TG), sterol ester(SE) and free fatty acid(FFA) while polar lipid (PL) fraction of TL contained phosphatidylcholine(PC) dominantly.

일부 도시지역 노인들의 우울과 일상생활능력에 관련된 요인

박원규,이태용,정용준,오장균,이동배,조영채 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

This study was performed to provide the basic data and related factors available for the assessment of the degree of ADL and depression among older persons, manifesting their physical and psychological status. The subjects included the old people aged more than 65 years old who reside in urban areas. The interviews were delivered to 693 individuals in Taejon metropolitan city during the two-month period from June to July, 2000, and Zung Self-Rating Depression Scale and IADL developed by Older American Resources and Services of Duke medical college, were employed for the assessment of depression and IADL, respectively. The collected data were statistically processed by SPSSWIN(ver 10.0) and led to the following results. The degree of depression among 635 subjects showed that 26.6% had mild depression, 8.2% moderate and 0.6% severe while 64.6% were normal. In terms of IADL, 6.9% had impossible IADL when not aided by others, 37.0% needed some help, 56.0% possible IADL, and the higher depression scores, the significantly higher IADL scores. Based on general characteristics, depression scores were significantly higher in the female group, the older, the lower educated, the ones without cohabitants, without a spouse, without making expenses of living on their own, and IADL scores were lower, meaning the lower capability for performing daily activities, in the male group, the older, the higher educated, the group without a spouse, without making expenses of living on their own. Based on daily activities and psychological characteristics, depression scores were higher in the group who don't go out, who don't have recreational or friendly gatherings, who aren't satisfied with the lives of the past or present, who have a sense of isolation, and who don't have the will to live, and IADL scores were lower in the group who don't go out, who don't have recreational or friendly gatherings, who aren't satisfied with the lives of the past or present, who have a sense of isolation. and who don't have the will to live. Multiple regression analysis revealed that the explanatory variable having effects on depression symptoms included, with the explanatory power of 57.5%, the confidence in life, the degree of education, the subjective index of health, the sense of isolation, the exercise, the degree of IADL, the gender, the level of satisfaction with life, whether they eat breakfast or not, the concern about life, the smoking, the going out, the presence of spouse or not. The explanatory variables having effects, with the explanatory power of 28.9%, on IADL scores included the degree of depression symptoms, the age, the presence of friends or not, the frequency of outgoing, the level of education, the degree of obesity, the confidence in life, the level of satisfaction with life, the drinking or not. The study results showed that the higher depression scores had a tendency to be associated with the decreased capabilities of performing daily activities, and that the factors related to depression and/or IADL, included the confidence in life, the level of education, and the level of satisfaction with life. However, the more detailed and decisive results on the factors related to depression and IADL of the older persons are considered to require continuing efforts and comparisons among a variety of the older population.

능동 클램프 ZVS 플라이백 컨버터의 역률개선에 관한 연구

최태영,류동균,이우석,안정준,원충연,김수석 성균관대학교 2002 학술회의지원논문목록집 Vol.2002 No.-

본 논문에서는 single-stage, two-stage 두가지 역률보상(PFC)기법을 기존의 능동 클램프 플라이백 컨버터에 적용하여 역률 개선을 하였다. 삽입된 플라이백 컨버터의 능동클램프회로가 주스위치와 보조스위치의 영전압스위칭(ZVS)을 구현하며, 스위칭 손실을 줄임으로써 고효율을 얻을 수 있고, 높은 주파수에서의 스위칭이 가능하다. 하지만 일반적으로 사용되는 다이오드정류기, 평활용커패시터에 의한 낮은 역률의 문제점이 남아있다. 본 논문에서는 300W급 능동 클램프ZVS플라이백 컨버터를 설계하여 single-stage, two-stage방식을 적용, 입력역률개선을 시뮬레이션과 실험에 의해 입증하고자 한다. This paper analyzed PFC of active clamp ZVS flyback converter by adding two method PFC (Power Factor Correction) circuit - two-stage and single-stage. The addition of active clamp circuit also provide a mechanism for achieving ZVS of both the primary and auxiliary switches. ZVS also limits the turn off di/dt of the output rectifier, reducing rectifier switching loss and switching noise, due to diode reverse recovery. As a results, the proposed converters have characteristics of the reduced switching noise and high efficiency in comparison to conventional flyback converter. The simulation and experimental results show that the proposed converters improve the input PF of 300W ZVS flyback converter by adding single-stage, two-stage PFC circuit.