Coronal flaring 전, 후 초기근관장 파일크기의 분석

황호길,박찬호,배성철 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.1

The purpose of this study was to compare the inital apical file(IAF) first file that fits to the apex in each canal before and after early flaring to analyze if the size of file to fit to the apex would increase after flaring. Eighty anterior teeth with complete apical formation and patent foramens were selected. The samples were randomly divided into 4 groups(GG, OS, GT, PT Group) of 20 teeth each. A file was fit to the apex in each canal and that size recorded. Radicular flaring were completed using different types of instruments. After flaring a file was again fit to the apex in the same manner as before and its size recorded. The results of this study were as follows: 1. The mean diameter of IAF before flaring(file diameters in mm ×10^-2) was 19.81±8.32 before and 25.94±9.21 after(p<0.05). 2. The increase in diameter of IAF was approximately one file size for all groups. 3. Ranking of increasing diameter of IAF were GG>GT>OS>PT Group. There was a statistically significant difference between before and after flaring(p<0.05). 4. Ranking of the time for flaring were GG>GT>OS>PT group. There was a statistically significant difference between GG group and other groups(p<0.05). 5. In the case without change of IAF diameter, they showed decrease in force after flaring when IAF was pulled out from root canal(p<0.05). This study suggested that early radicular flaring increases the file size that is snug at the apex, and awareness of that difference gives the clinical a better sense of canal size. Early flaring of the canal provides better apical size information and with this awareness, a better decision can be made concerning the appropriate final diameter needed for complete apical shaping.

정신과 환자들의 의료서비스 이용에 관한 연구 : 경기도 연천 지역에서 In Yonchon Area of Kyunggi Province

황성혜,홍진표,권준수,우종인,김중술,조두영,이부영,조맹제,양병국,배재남 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.4

본 연구는 농촌지역 정신과 환자들의 의료서비스 이용 형태를 알아보고자 하여 행하여졌다. 경기도 연천군 주민중 1993년 1년간 지역 의료보험과 의료보호자료에서 정신과적 진단을 받은 사람들 1295명 중 209명을 대상으로 하였다. 연구자들이 제작한 반구조화된 면담도구를 사용하여 13명의 훈련된 면담자에 의해 증상을 처음 느낀 후 이용한 의료서비스를 차례대로 조사하였다. 결과는 다음과 같다. 정신증적 장애 환자들은 정신과 치료만을 받은 경우가 28.8%이며 처음 방문한 의료서비스는 정신과 45%, 일반의 28%, 약국 6%, 한방치료 5%, 요양원 6%, 기타 10%였다. 비정신증적 장애 환자들은 정신과를 한번이라도 이용한 경우는 32.1%였고 처음 방문한 의료서비스는 정신과 15%, 일반의59%,약국 17%, 한방치료8%, 기타1%였다. 진단에 따라서는, 정신분열병의 경우 64.5%가 처음에 정신과를 방문하였고 정동형 정신병의 경우는 20.8%에 불과했고 64.1%가 일반이나 약국을 처음에 방문하였다. 신경증적 장애(ICD-9 300)는 40.0%가 일반의만을 방문했다. 이상의 결과로 정신분열병 환자들은 대다수가 정신과 치료를 받는 것으로 나타났으나 정동형 정신병과 신경증적 장애는 다수가 일반의를 이용하는 것으로 나타났다. 지역사회 정신보건에서 일반의의 역할이 매우 중요하며 일반의에 대한 정신과 교육이 절실하고, 보다 전문적인 치료환경과 기술을 요하는 경우에는 정신과와의 연계 체계의 필요성도 요구된다. The purpose of this study was to investigate the pathways of health care seeking by the psychiatric patients at a well - defined rural area in Korea. Among 1,295 patients diagnosed to have mental disorders by ICD-9 in a year, all the psychotic patients(184 in number) and randomly selected 15% of nonpsychotic patients(162 in number) were selected as subjects of this study. Thirteen well - trained interviewers collected the data using semi-structurd inter-view instrument developed by the authors. Two hundred nine patients(60.4%) fully responded to the interviews. As for psychotic patients, 28.8% used only psychiatric services, and the first visits for help were psychiatrists, general practitioners, pharmacists, asylums and oriental herb medicine in the order of decreasing frequency. Only 32.1% of nonpsychotic patients used mental health specialties during the course of their illness, and their most common first visits for care were general practitioners(59%) followed by pharmacists(17%) and psychiatrists(15%). Majority(64%) of schizophrenic patient visited psychiatrist first, while 64.1% of affective psychosis patients visited general practitioners and pharmacists first. The forty percent of neurotic patients(ICD-9 300) visited general practitioners only for their health care.

Coronal flaring 전, 후의 근관세척효과

황호길,배성철,조영린 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.1

The objective of this in vitro study was to evaluate the efficacy of a Ca(OH)_2 removal before and after early coronal flaring using different types of instruments. 100 plastic blocks with 30°artificial curved canals were used in this study and randomly divided into a control group and 4 experimental groups(GG, OS, GT, PT Group) 20 teeth each. The canals were instrumented, and Ca(OH)_2 was temporary filled into the each canal. Irrigation was performed with Max-i-Probe 25-, 30-gauge probes before and after recapitulation. The results of this study were as follows: 1. There were no significant difference among the groups in size of irrigating needle(p<0.05). 2. There was a significant difference between before and after recapitulation regardless size of irrigating needle(p<0.05). 3. Before recapitulation, there was a significant difference between 25- and 30-gauge needle in all groups(p<0.05). 4. After recapitulation, there was a significant difference between 25- and 30-gauge needle in the control group(p<0.05). But there were no significant difference among the experimental groups. It is concluded that the effectiveness of canal irrigation was decided to the depth of irrigating needle into the canal. The effect of canal irrigation tend to facilitate by the early coronal flaring. The recapitulation was the most effective during canal irrigation regardless the size of irrigating needle. Therefore, the recapitulation is a mandatory way to facilitate the effectiveness of canal irrigation during canal enlargement.

슬라이딩 모드 전기-유압 서보 제어기 설계

황이철,김성배 동의대학교 산업기술개발연구소 2001 産業技術硏究誌 Vol.15 No.-

This paper describes the model identification and the discrete-time sliding mode control of electro-hydrauric servo systems which are composed of servo valves, double-rod cylinder and load mass. The controlled plant is identified as a 3th-order discrete-time ARMAX model obtained from the prediction error algorithm, where a nominal model and modeling errors are quantitatively constructed. The discrete sliding mode controller for 3th-order ARMAX model is designed in discrete-time domain, where all states are observed from Kalman filter. The discrete sliding mode controller has better tracking performance than that obtained from continuous-time sliding mode controller, in experiment.

일반인구에서 유전자 다형성이 요중 1-hydroxypyrene 및 2-naphthol의 배설량에 미치는 영향

황문영,조병만,문성배 한국환경과학회 2005 한국환경과학회지 Vol.14 No.5

This study was performed to determine the effects of genetic polymorphisms, such as glutathione S-transferase μl (GSTM1), glutathione S-transferase Φl (GSTT1), glutathione S-transferase π1 (GSTP1), aryl hydrocarbon N-acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), cytochrome P450 IA1 (CYP1AI) on the concentrations of urinary 1-hydroxypyrene (1-OHP) and 2-naphthol in general population with no occupational exposure to polycyclic aromatic hydrocarbons (PAHs). Study subjects were 257 men who visited a health promotion center in Busan. A questionnaire was used to obtain detailed data about age, smoking, drinking, body fat mass, intake of fat etc. Urinary 1-OHP and 2-naphthol concentration were analyzed by HPLC system with a fluorescence detector. A multiplex PCR method was used to identify the genotypes for GSTM1 and GSTT1. The polymorphisms of GSTP1, NAT2, CYP1A1 and CYP2E1 were determined by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. Urinary 1-0HP concentration was higher in deleted genotype of GSTMI, increased as smoking and alcohol drinking increased. Urinary 2-naphthol concentration was also rely on the age and smoking. Neither genetic polymorphism nor drinking-related factors were significantly related to urinary 2-naphthol concentration. No significant relation was found between physical characteristics and concentrations of urinary PAHs metabolites in the subjects, but the geometric mean of urinary 1-OHP and 2-naphthol was higher in the group with higher value compared to median value. These data suggest that in general population occupationally not exposed to PAHs, urinary concentration of PAHs metabolites is influenced by smoking, alcohol drinking and deleted genotype of GSTM1 in 1-OHP and smoking in 2-naphthol.

olanzapin과 Risperidone의 급성 및 만성 투여기가 흰쥐 전전두피질의 Dopamine 농도에 미치는 영향

문선근,정영철,은홍배,황익근,박태원 大韓神經精神醫學會 2002 신경정신의학 Vol.41 No.1

항정신병약물들이 전전두피질의 세포외 dopamine 농도에 미치는 영향은 이 약물들의 음성 증상에 대한 효과와 관련이 있는 것으로 보고 되고 있다. 따라서 본 연구에서는 최근 국내에서 많이 사용되고 있는 olanzapine과 risperidone을 흰쥐에 급성 및 만성 투여를 한 후, 이들 약물들이 전전두피질의 세포외 dopamine 농도에 미치는 영향을 알아보고자 하였다. 샘플은 생체 내 뇌 미세투석법(in vivo brain microdialysis)을 이용하여 얻었고 샘플내 dopamine의 농도는 전기화학적 검출법(electrochemical detection : ECD)을 사용하는 고압액체크로마토그라피(high pressure liquid chromatography : HPLC)로 측정하였다. 그 결과는 다음과 같다. 1) Olanzapine과 risperidone의 급성 투여는 전전두피질 부취의 세포외 dopamine 농도를 증가시켰으며 증가의 정도는 용량 의존적이었다. 2) Olanzapine과 risperidone의 급성 투여에 의해 전전두피질 부위에 나타난 세포외 dopamine 농도의 최고치는 두 약물간에 유의한 차이가 없었다. 3) Olanzapine과 risperidone의 만성 투여는 전전두피질 부위의 세포외 dopamine 농도를 증가시켰으나 그 증가의 정도가 급성 투여에 비해 모두 감소하는 내성 현상이 보였다. 4) Olanzapine과 risperidone의 만성 투여에 의해 전전두피질 부위에 나타나는 세포외 dopamine 농도의 최고치는 olanzapine과 risperidone에 비해 유의하게 높았다. 이상의 결과들은 Olanzapine과 risperidone의 음성 증상에 대한 임상적 효과가 이들 약물이 전전두피질의 세포외 dopamine 농도를 증가시키는 효과와 관견이 있음을 제시한다. Object : It is reported that the effect of antipsychotics on the extracellular dopamine levels in the prefrontal cortex is related to the their effect on the negative symptoms. Therefore, we investigated the acute and chronic effects of olanzapine and risperidone on the extracellular dopamine concentrations in the prefrontal cortex of rat. Samples were obtained using in vivo brain microdialysis. Method : Dopamine levels in the samples were measured by high pressure liquid chromatography with electrochemical detection. Results : 1) Both the acute treatment of olanzapine and risperidone increased the extracellular dopamine concentrations in the prefrontal cortex, dose-dependently. 2) There was a no significant difference in the maximal change of the extracellular dopamine concentrations in the prefrontal cortex induced by the acute treatment of olanzapine and risperidone. 3) Both the chronic treatment of olanzapine and risperidone also increased the extracellular dopamine concentrations in the prefrontal cortex, but they showed the tolerance effect that the degree of increase was smaller than that of the acute treatment. 4) As for the maximal changes of the extracellular dopamine concentrations in the prefrontal cortex induced by the chronic treatment of planzapine and risperidone, the effect of the former was greater than that of the latter. Conclusion : These results suggest that the effects of olanzapine and risperdone on the negative symptoms are related to the increased extracellular dopamine concentrations in the prefrontal cortex induced by these drugs.

ILQ 제어를 이용한 열간압연 폭 제어시스템 개발에 관한 연구

김성배,황이철 동의대학교 산업기술개발연구소 2001 産業技術硏究誌 Vol.15 No.-

This paper studies on the design of a ILQ(Inverse Linear Quadratic optimal control) looper control system for hot strip mills. The looper which is placed between each stand plays an important role in controlling strip width by regulating strip tension variation generated from the velocity difference of main work rolls. The mathematical model for looper is firstly obtained by Taylor's linearization of nonlinear differential equations, where it is given as a linear and time invariant state-space equation. Secondly, a looper servo controller is designed by ILQ control algorithm, which is an inverse problem of LQ(Linear Quadratic optimal control) control. By tunning control gain arbitration parameters and time constants, it is shown that the ILQ looper servo controller has the performance that makes well to follow desired trajectories of both strip tension and looper angle.

인적오류에 의한 항공사고 분석

장성록,황진태,배동철 釜慶大學校 2001 釜慶大學校 論文集 Vol.6 No.-

This study aimed to investigate the human-related causes of aircraft accidents and present the basic data for developing human-error prevention program. Peterson's model of accident causation and Cooper's model of safety culture were applied to analyze the severe causes of aircraft accidents for last 10 years. For analyzing the causes of aircraft accidents, expert's opinion method was adopted. The analyses showed that the overload and decision error were major causes of aircraft accidents. The causes and backgrounds of human error were found with respect to human, tasks, organization.

충수염의 임상적 고찰과 초음파의 유용성

박정배,양혁준,김형수,황성연,박철완,이근 대한응급의학회 1995 대한응급의학회지 Vol.6 No.2

Appendicitis is the most common acute abdomen in Emergency Medical Center & outpatient department. But sometimes, it is difficult for us to diagnose because of clinically variable symptoms. We reviewed the ultrasonographic findings and analyse 521 cases of appendectomy patients about its distribution of sex and age, seasonal prevalence, clinical symptom and signs, laboratory findings, duration from onset of symptom to arrival at hospital, duration from arrival at hospital to operation, vital signs, operative results, and associated diseases, which were treated at the department of General Surgery & Emergency Medical Center in Chung Ang Gil Hospital from July, 1994 to June, 1995. The results were as follows : 1. The most common age group was second decade. And male to female ratio was 1.43:1. Seasonal variation was not significant. 2. Of 521 cases, 141 cases(27.1%) visited the hospital within 24 hours from the onset of symptom, and 259 cases(49.7%) visited between 24 to 48 hours. 3. In duration from arrival to operation, the cases within 6 hours were 263 (50.5%), the cases between 6 and 12 hours were 131(25..1%). 4. In systolic blood pressure, cases below 90mmHg were 19(3.6%), cases above 160mmHg were 23(4.4%). Below 60mmHg diastolic pressure were 55 cases(10.6%), cases above 110mmHg were 9(1.7%). In pulse rate, above 90 rate/min were 171(32.8%). 5. On admission leukocytosis was found in 413 cases(79.3%) and 342 cases of them were pathologic appendicitis. 6. Ultrasoundgraphy was performed in the 87 cases, but 23 cases were suggested appendicitis. Among 23 cases, 22(95.7%) revealed pathologic appendicitis at ooperation and labortatory examination. Of the 64 cases which were normal on ultrasonography, only 2 cases(3.1%) were proved to be appendicitis. 7. The results of 496 operations without ultrasonography were appendicitis in 390 cases(78.6%), mesenteric lymphadenopathy 36(7.3%), pelvic inflammatory disease 28(5.6%), fecalith 15(3.0%), terminal ileitis 8(1.6%), diverticulitis 7(1.4%), urinary tract stones 5(1.0%), cecal cancer 2 cases, right ovarian tumor 2 cases, tubo-ovarian abscess 2 cases, grater omentum internal hernia 1 case. Our results showed that the sensitivity of ultrasonohraphy was 95.8% and the specificity 98.4% in the diagnosis of appendicitis, It suggests that the ultrasonography is very helpful in the diagnosis & differential diagnosis of acute appeendiditis.

외상환자의 중증도분류를 위한 Triage Score와 Triage-Revised Trauma Score의 비교

조광원,황성연,배성만 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: The triage-revised trauma score(t-RTS) is used for triage in trauma patients in many countries. Recently, the triage score was developed as a new triage method for trauma patients in Korea. The objective of this study was to assess the accuracy of triage for the t-RTS and the triage score. Methods: The medical records of 1575 consecutive trauma patients visiting the Emergency Center, Masan Samsung Hospital, from March to August 1999 were retrospectively analyzed. The triage score and the t-RTS were taken from the charts completed by the emrgency room doctors and nurses. The accuracies of the two triage methods were compared by using the undertriage and the overtriage rates, receiver operating characteristic(ROC) curve analysis, and a correlation analysis with many physiologic, anatomical, biochemical, and mixed scores(Glasgow coma scale, injury severity score, TRISS, APACHE II and III scores, operation, survival, etc.). Results: The undertriage rates for the triage score and the t-RTS were 22.8% and 38.2%, respectively(p≤0.001), the overtriage rates were 6.3% and 3.1%, respectively,(p≤0.001), and the accurate triage rates were 91.3% and 91.7%, respectively. The areas under ROC curves for the triage score and the t-RTS were 0.871±0.033 and 0.800±0.039, respectively(95% confidence interval, p<0.001). In general, the correlations of the two triage methods with many physiologic, anatomical, biochemical, and mixed scores were moderately high, but there were no statistical differences between the correlation coefficients of the two triage methods for those scores. Conclusion: The triage score was equal or superior to the t-RTS for triage in trauma patients. The former was simpler and could be used easily by emergency medical personnel. Therefore, the authors conclude that the triage score can be used instead of the t-RTS for triage in trauma patients.