근관충전방법에 따른 치근단부 근관의 미세누출에 관한 연구

유형준,홍찬의 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1

Advisor : Prof. The quality of apical seal obtained with 3 different gutta-percha obturation techniques was compared in 49 recently extracted single rooted teeth. The root canals were instrumented using step-back technique and obturated with laterally condensed gutta-percha, Continuous Wave gutta-percha, and hybrid technique. Teeth were suspended in black India ink for 7 days, cleared, and then examined under a stereomicroscope at x10 magnification. The results were as follows ; 1. All experimental groups produced favorable apical seal. 2. The mean leakage was 0.23±0.25 mm for group 1, 0.17±0.21 mm for group 2, and 0.19± 0.23 mm for froup 3, but there was no statistical difference amoung them. Within the limits of the results of this experiment, the Continuous Wave gutta-percha obturation technique demonstrated relatively favorable apical sealing effect and shorter obturation time. Thus, it is thought that this obturation technique is a acceptable method for clinical use but further studies on this metter should be conducted.

이면성 및 도플러 심초음파도를 이용하여 진단한 선천성 거대 좌회선지-좌심실 관동맥루

진승원,박준철,이영중,유병현,박현옥,김용주,윤호중,김재형,홍순조,최규보,권종범,원용순,박건 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4

Cadmium이 넙치(Paralichthys olivaceus)의 면역 반응에 미치는 영향

변주영,유민호,전려진,이형호,정현도 한국어병학회 2001 한국어병학회지 Vol.14 No.2

어류의 면역반응에 대한 cadmium (Cd)의 영향을 분석하기 위하여 넙치 (Paralichthys olivaceus)를 각기 다른 방향으로 Cd에 노출시킨 후 특이적 면역반응의 변화와 Edrwrdsiella tarda KFE (E. tarda KFE)의 인위감염에 대한 저항성을 분석하였다. E. tarda KFE의 formalin killed cell (FKC)로 면역시키기 2주전부터 계속하여 실험 기간동안 침지법으로 Cd(20ppb)에 노출된 시험구는 노출되지 않은 시험구와 양성 대조구보다 혈청 내 특이 항체가가 빠르게 최고치에 이르렀으나, 감소속도는 노출시키지 않은 양성 대조구에 비하여 빠른 것으로 나타났다. 이러한 경향은 splenocytes를 ELISPOT-assay (enzyme-linked immunospot assay)를 이용하여 특이 항체 생성 세포 (specific antibody secreting cell, SASC) 수를 분석해 보았을 때에도 동일하게 나타났다. 그러나 면역 전 2주 동안만 Cd에 노출시킨 시험구에서는 혈청내 항체생성 결과와는 달리 증가된 SASC의 수를 보여 주었다. 그리고 면역 2주 전부터 실험 전기간동안 계속해서 Cd에 노출시킨 넙치를 대상으로 하여 E. tarda FKC 생균으로 인위 감염시켰을 때 100% 폐사율을 보여 주었다. 이것은 Cd에 지속적으로 노출된 어류에서의 방어 체계는 면역반응뿐만 아니라 독성효과도 함께 고려되어야 하는 복합적인 것임을 확인 할 수 있었다. Olive flounder, Paralichthys olivaceus known as an one of the major aquacultured species in Korea were exposed to cadmium(Cd) with different protocols and analyzed the effects of exposure on the immune response. Antibody levels in sera of the group exposed to Cd(20ppb) by immersion method from 2 weeks before immuniztion with formalinised Edwardsiella tarda(E. tarda) KFE entigen to the end of experiment reached to peak level faster than that of the non-exposed group. After this peaking time the levels decreased much at a faster rate compared to the non-exposed group. This tendency was also appeared in the numbers of specific antibody secreting cells(SASC) analyzed with the enzyme-linked immunospot (ELISPOT)-assay technique in the splenocytes of the experimental groups exposed to Cd with different ways. Interestingly, the group exposed to Cd for 2 weeks before immunization also showed increased numbers of SASC unlikely the antibody production and suggested a more critical influence of cadmium exposure in early stage of immune reaction. Artificial infection with live E. tarda KFE induces 100% mortality in the flounder exposed to cadmium throughout the experimental period from two weeks before the immunization. It may imply that some other factors related to specific immunity are involving in the defence system of flounder exposed to Cd. Taked together. Cd exposure may induce temporaily stimulatory or indhibitory effects on the immune reaction, but suppress the physiological systems for the resistant against the infective agents with other toxic effects.

우라늄 이온의 선택흡착

정종헌,김준수,오원진,유재형,유승곤 한국공업화학회 2002 응용화학 Vol.6 No.1

Uranium-containing aqueous wastes have been treated by electrosorption on a carbon electrode composed of activated carbon fibers(ACFs) in a continuous flow-through cell. Effective uranium (VI) removal is accomplished when a negative potential in the range of -0.3 to -0.9V (vs. Ag/AgCI) is applied to the carbon electrode. For a feed concentration of 350mg/l, the concentration of U(VI) in the cell effluent is reduced to less than lmg/l. Electrosorption capacity over 552 mg_uranium/g_ACF is reached.

고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 박판재 절단시 공정변수의 절단표면특성에 미치는 영향

안동규,김민수,이상훈,유영태,박형준 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

The objective of this research work is to investigate the influence of process parameters, such as power of laser, travel speed of laser and material thickness, on roughness and striation of the cut surface for the case of cutting of CSP IN sheet using high power Nd:YAG laser with continuous wave (CW). In order to find the practical cutting region and the relationship between process parameters on the roughness and the striation, several laser cutting experiments are carried out. From the results of experiments, the allowable cutting region and an optimal cutting speed for each cutting condition have been obtained to improve the quality of the cut surface. In addition, it has been shown that the surface roughness is related to the number of striation and depth of valley of the cut surface.

쿠싱증후군 환자에서 당 대사 이상 정도에 따른 인슐린 감수성과 인슐린 저항성의 변화

정인경,김성훈,정재훈,민용기,이명식,이문규,유형준,안규정,노정현,김동준,김광원 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.4

연구배경 당질 코르티코이드는 당 대사에 매우 중요한 호르몬으로 내인성 당질 코르티코이드 과다상태인 쿠싱증후군에서는 말초조직에서 인슐린 저항이 증가하고 이를 보상하고자 인슐린 분비의 증가로 고인슐린혈증이 동반된다고 보고되고 있다. 하지만 생체 내에서와 달리 시험관내에서는 췌도세포에 당질 코르티코이드를 장시간 처리하면, 인슐린 분비 및 생합성이직접적으로 억제됨이 확인된 바 있어 쿠싱증후군 환자에서 당뇨병의 원인으로는 아마도 말초조직에서 증가된 인슐린 저항성 뿐 아니라 이를 충분히 보상하지 못하는 췌장에서의 인슐린 분비 저하가 같이 동반되어있지 않을까 하는 가설을 세우게 되었고, 아직까지 당질코르티코이드가 당대사 이상을 일으키는 기전에 대해 쿠싱증후군을 당대사 정도에 따라 인슐린 감수성과 분비능을 분석한 연구는 없었기에 이를 알아보고자 하였다. 방법: 삼성서울병원에서 쿠싱증후군으로 진단 받은 환자 15명을 대상으로 하였다. 이에 대한 대조군으로는 쿠싱증후군 환자와 같은 성별 그리고 체질량지수를 갖은 15명의 건강한 성인을 대상으로 비교 하였다 쿠싱증후군 환자를 대상으로 경구당부하 검사를 통해 당대사 정도를 정상군, 내당능장애군, 그리고 당뇨병군으로 나눈 후 정맥 당부하 검사를 시행하여 각군의 인슐린 저항성과 인슐린 분비능의 지표를 비교하고, 수술 후 쿠싱증후군이 완치된 상태에서 수술 전후의 당대사 지표의 변화를 조사하였다. 결과: 1) 쿠싱증후군 환자 중 정상인은 20%, 내당능 장애는 27%, 그리고 당뇨병은 53%였다. 체질량지수, 나이, 그리고 발병 기간은 세 군간에 의미 있는 차이가 없었으나, 24시간 소변검사의 코르티솔 농도는 당뇨병군에서 의미있게 높았다. 2) 정맥당부하 검사 결과, 인슐린 감수성 지표인 Sl는쿠싱증추린」서 1.58±0.10[×10^(-4)(min^(-1)(μU/mL)^(-1)]로 정상 대조군의 3.37±0.49[×10^(-4)(min^(-1)(μU/mL)^(-1)]에 비해 의미있게 낮았으나(P=0.024), 쿠싱증후군 환자 중 NGT, IGT, DM 군간에 서로 통계적인 차이는 없었다. 3) SG는 정상 대조군과 쿠싱증후군 환자간에는 의미있는 차이가 없었고, 쿠싱 증후군에 있어서 당대사가 악화될수록 감소하는 경향을 보였으나 의미있는 차이는 없었다. 4) 인슐린 분비능의 지표인 AIRg는 정상인에 비해 전체 쿠싱증후군 환자의 경우 증가하는 경향을 보였으나 의미있는 차이는 없었다. 하지만 쿠싱증후군 환자중에서 당대사 상태에 따라 NGT군은 1299 (1297∼1310)(mu/g/min ×10^(-2))로 정상 대조군(368.9±98.6[mu/g/min ×10^(-2)]) 보다도 의미있게 높았고, DM군{202.2 (91.1~371.4) [mu/g/min ×10^(-2)}은 NGT군에 비해 의미있게 낮았다(P=0.0031). 5) 15명중 현재 완치 상태에 있는 6명에 대해 수술전과 후로 비교하였다. 수술 전 당대사 상태가 1명은정상, 1명은 내당능 장애, 그리고 4명은 당뇨병이었으나 수술 후 시행한 경구 당부하 검사상 모두 정상 당대사 상태를 보였다. 6) 수술 후 완치된 환자 6명에 있어 인슐린 감수성지표인 Sl는 수술전에 중앙값이 1.22[×10^(-4)(min^(-1)(μU/mL)^(-1)]로 대조군에 비해 의미있게 감고』어 있었으나(p.0.05), 수술후 10.95 [×10^(-4)(min^(-1)(μU/mL)^(-1)]로 정상 수준으로 회복되었고(P=0.0022), 인슐린 분비능을 나타내는 AIRg [mu/g/min ×10^(-2)] 값도 정상수준으로 회복되었다. 특히 인슐린 분비능의 회복양상은 혈당농도에 따라 판이하게 나타나서, 정상과 내당능장애 상태에 있던 2명은 수술전에 1201 [mu/g/min ×10^(-2)]로 증가되어 있던 AIRg 값이 수술 후 정상 수준으로 감소하였고, 수술 전에 당뇨병 상태에 있던 4명의 경우 245.9 [mu/g/min ×10^(-2)]로 인슐린 분비능이 감고il어 있었는데 이들은 수술 후 모두 정상 수준으로 증가되었다 (P=0.0286). 결론: 쿠싱증후군 환자에서 당대사 이상은 80%로 높은 유병률을 보였다. 모든 쿠싱증후군환자에서 인슐린 감수성은 정상인에 비해 저하되어 있어 말초조직의 인슐린 저항이 선행됨을 시사하며, 인슐린 분비능은 당대사의 정도에 따라 다르게 나타났는데, 정상 당대사군에서는 인슐린의 저항성을 극복할 만큼 정상 대조군보다 더 많은 양의 인슐린 분비를 하다가 고코르티솔혈증이 심할수록 인슐린 분비능의 감소로 당뇨병으로 진행됨을 확인할 수 있었고, 이런 인슐린 저항성과 인슐린 분비장애는 수술 후 다시 회복되는 가역적인변화를 보였다. Background: Glucocorticoid plays an important role in the control of carbohydrate metabolism. Patients with Cushing's syndrome have been reported to have an increased incidence of carbohydrate intolerance due to peripheral insulin resistance and hyperinsulinemia, although the exact incidence and nature of this disorder have remained unclear. Few results have been published about insulin resistance and insulin secretion according to the level of glucose concentration, or about the reversibility of such defects in patients with Cushing's syndrome. Methods: To assess the effect of glucocorticoid on the insulin sensitivity and insulin secretion in Cushing's syndrome, 15 patients with Cushing's syndrome were classified into 3 groups (normal glucose tolerance: NGT, impaired glucose tolerance: IGT, diabetes: DM) according to the degree of glucose tolerance based on the oral glucose tolerance test (OGTT). Insulin modified, frequently sampled, intravenous glucose tolerance test (FSIGT) was performed before and after curative surgery on these patients and on 15 healthy control subjects. Data were evaluated by non-parametric statistical analysis. Results: 1) Among the 15 patients with Cushing's syndrome, 3 (20%) were NGT, 4 (27%) IGT, and 8 (53%) DM, based on OGTT. Twenty-four hour urinary free cortisol (UFC) was significantly higher in the DM group. 2) Insulin sensitivity index (SI) of Cushing's syndrome was significantly lower than that of the control group p=0.0024), but was not significantly different among the three Cushing's syndrome groups of NGT, IGT and DM. 3) Glucose mediated glucose disposal (SG) (Ed- confirm this abbreviation; it does not seem to match the definition) of Cushing's syndrome was not significantly different from that of the control group. 4) Insulin secretion (AIRg) of Cushing's syndrome tended to be high, but it was not significantly different from that of control. However, according to the level of glucose concentration there was significant difference in AlRg among the three Cushing's syndrome groups p=0.0031); AIRg of DM was significantly lower than that of NGT. 5) After surgical treatment, parameters of insulin sensitivity and insulin secretion were normalized in 6 cured patients; 1 with NGT, 1 with IGT, and 4 with DM, preoperatively. Median SI of all 6 patients was significantly improved up to the normal range postoperatively p=0.0022). Median AIRg of these 6 patients was balanced around that of normal control postoperatively p=0.0286). Conclusion: Eighty percent of patients with Cushing's syndrome had abnormality of carbohydrate metabolism. Insulin sensitivity was significantly decreased in Cushing's syndrome. Insulin secretion was significantly higher only in the NGT and IGT groups of Cushing's syndrome. As the hypercortisolemia is exacerbated, insulin secretion is significantly decreased and causes DM, suggesting that glucocorticoid has a direct or indirect toxic effect on the pancreatic beta cell (J Kor SOC Endocrinol 18:392-403, 2003).

Development of an Upper Limb Muscle Synergy-based Rehabilitation Game Interface

Yoo-jin Jun(전유진),Han-gil Lee(이한길),Hyeok-Jun Kwon(권혁준),Hyung-Soon Park(박형순) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Development of an Upper Limb Muscle Synergy-based Rehabilitation Game Interface

Yoo-jin Jun(전유진),Han-gil Lee(이한길),Hyeok-Jun Kwon(권혁준),Hyung-Soon Park(박형순) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Unregulated BUS converter를 사용한 3㎾급 에너지 저장용 양방향 컨버터

채형준(Hyung-Jun Chae),이윤재(Yun-Jae Lee),윤수영(Su-Young Yun),오은태(Eun-Tae Oh),유광민(Kwang-min Yoo),이준영(Jun-Young Lee) 전력전자학회 2009 전력전자학술대회 논문집 Vol.2009 No.1

A concern about renewable energy is elevated, because of global warming to emission carbon dioxide, the drain on fossil fuel and high oil prices. Renewable energy in power systems need some energy storages to get over the characteristic of discontinuously generating. In this paper, the 3kW bi-directional DC-DC converter is proposed using unregulated BUS converter. This proposed converter which has high efficient and high power density is verified by experimental result.

복벽 손상 백서에서 세가지 유형의 유착방지제의 효과

송형준(Hyung Jun Song),김종원(Jong Won Kim),박준석(Jun Seok Park),김용석(Yong Seok Kim),최유신(Yoo Shin Choi),김범규(Beom Gyu Kim),차성재(Sung Jae Cha),박성준(Sung Jun Park),장인택(In Taik Chang),박성일(Sung Il Park),박언섭(Eon Sub P 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.77 No.1

Purpose: Postsurgical adhesion formation is a significant clinical problem within every surgical specialty. Several adhesion barriers have been developed in the form of solution, membrane or film in an attempt to solve these problems. The purpose of the present study is to compare the efficacy of antiadhesive agents in the prevention of postsurgical adhesion formation in a standardized rat adhesion model. Methods: We examined forty Sprague-Dawley rats, which is a cecal abrasion with partial peritonectomy model. Three treatment groups (Group Ⅰ: Film-type Surgiwrap<SUP>ⓡ</SUP>, Group Ⅱ: Solution-type Guardix-sol<SUP>ⓡ</SUP>, Group Ⅲ: Membrane-type Interceed<SUP>ⓡ</SUP>), each consists of 10 rats, and a control group of 10 rats were used by saline. Ten days after surgery, the rats were killed, and the levels of adhesion were graded. Immunohistochemical staining for microvessel density (CD34, MVD) and macrophage (ED1) were performed in adhesion tissue. Results: The peritoneum adhesion mean scores are as follows: control group: 2.2±0.78, Group Ⅰ: 1.0±1.06, Group Ⅱ: 0.9±0.99, Group Ⅲ: 0.6±0.84. All treatment groups showed significantly less peritoneum adhesion (P=0.006), while there was no significant difference in each group. The intraperitoneal organs adhesion mean scores are as follows: control group: 2.8±0.91, Group I: 2.6±1.06, Group Ⅱ: 1.4±0.84, Group Ⅲ: 1.0±0.81. Group Ⅰ had no significant difference about intraperitoneal organs adhesion with control group, but Group Ⅱ and Group Ⅲ showed less intraperitoneal organs adhesion. The mean numbers of microvessel density are as follows: control group: 42.5±4.83, Group Ⅰ: 40.8±6.53, Group Ⅱ: 30.9±6.15, Group Ⅲ: 15.60±4.37, from which there was a significant difference between Group Ⅱ and Group Ⅲ with control group (P<0.001). The mean numbers of macrophage are as follows: control group: 223.3±33.12, Group I: 211.25±10.96, Group Ⅱ: 171.60±23.96, Group Ⅲ: 147.0±12.22, from which there was a significant difference between Group Ⅱ and Group Ⅲ with control group (P<0.001). Conclusion: In our animal model, three different types of antiadhesive agents (Surgiwrap<SUP>ⓡ</SUP>, Guardix-sol<SUP>ⓡ</SUP>, Interceed<SUP>ⓡ</SUP>) were effective in adhesion prevention, but Surgiwrap<SUP>ⓡ</SUP> had less antiadhesive effect for intraperitoneal organs adhesion. Membrane-type Interceed<SUP>ⓡ</SUP> had a better effect for microvessel density (MVD) and macrophage than solution-type Guardix-sol<SUP>ⓡ</SUP>.