Cone beam형 전산화단층영상을 이용한 하악과두 위치의 연구

황형주,김규태,최용석,황의환 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.36 No.2

Purpose : To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Materials and Methods : Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or prosthodontic treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. Results : In the sagittal views, mandibular condyle within articular fossa was posteriorly located at medial and central sections. In the coronal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Conclusion : Mandibular condyle within articular fossa in an asymptomatic population was observed nonconcentric position in the sagittal and coronal views.

중합효소연쇄 반응법에 의한 인형거대세포바이러스(human cytomegalovirus)의 신속한 검출

김의종,오명돈,박기호,신형식,이환종,김남중,최강원 대한감염학회 1996 감염 Vol.28 No.4

목 적 : 인형거대세포바이러스(HCMV)는 면역 저하 환자에서 폐렴, 망막염, 간염 등 치명적인 감염증의 원인이다. 전통적인 세포 배양법으로 HCMV를 분리하기까지는 1주에서 4주가 걸리므로 이 바이러스에 의한 질환이 의심되는 경우 신속한 진단법을 이용한 진단이 바람직하다. 저자들은 한국에서 분리되는 야생주 HCMV를 검출하는데 중합효소 연쇄 반응법을 이용할 경우의 진단적 유용성을 알기 위하여, 전통적인 세포배양법으로 HCMV가 분리된 검체를 이용하여 중합효소 연쇄 반응법의 특이도와 민감도를 평가하였다. 방 법 : 국내 야생주 HCMV 15주, 그리고 전통적인 바이러스 배양법으로 HCMV가 분리된 소변 15검체를 대상으로 중합효소 연쇄 반응을 실시하였다. 중합효소 연쇄 반응은 Towne주의 immediate early antigen의 유전자에서 유리된 primer MIE와 AD169주의 immediate early antigen의 유전자에서 유리된 primer IE를 이용하였다. 증폭 산물은 겔 전기영동 후 EtBR으로 염색하여 자외선 하에서 관찰하였다. Primer IE에 의한 증폭산물은 또한, DNA blot hybridization 방법으로 확인하였다. 결 과 : 1) 국내 HCMV 야생주 15주를 대상으로 중합효소 연쇄 반응을 한 결과 primer IE를 이용한 경우에는 100%(15/15)에서 177bp의 증폭 산물이 관찰되었고, 이들 증폭 산물은 모두 probe IE와 보합 결합되었다. primer MIE를 이용한 경우에는 93%(14/15)에서 435bp의 증폭 산물이 관찰되었다. 2) 세포 배양법으로 HCMV가 분리된 소변 15검체를 대상으로 primer IE를 이용하여 중합효소 연쇄 반응을 한 결과 direct gel analysis 법으로는 73%(11/15)에서, 보합 결합법으로는 87%(13/15)에서 관찰되었다. Primer MIE를 이용한 경우에는 direct gel analysis법으로 87%(13/15)에서 435bp의 증폭 산물이 검출되었다. 결 론 : Primer IE와 MIE를 이용한 중합효소 연쇄 반응법은 국내 야생주 HCMV를 신속히 검출하는데 유용한 검사법이다. Background : Human cytomegalovirus(HCMV) can cause pneumonitis, hepatitis, retinitis and other serious diseases in the immunocompromised patients. It takes 1 to 4 weeks to diagnose HCMV infection by conventional virus culture. Therefore, when HCMV diseases are suspected, a rapid diagnostic method such as polymerase chain reaction(PCR), antigen assay or shell vial culture is desirable. We evaluate the sensitivity and specificity of a PCR for the rapid detection of HCMV wild strains in Korea. Methods : We used 2 sets of primers ; primer IE and primer MIE derived from the sequence for immediate early gene of AD169 strain and Towne strain, respectively. Fifteen clinical isolates of HCMV, suspended in MRC-5 cells, were amplified by PCR. Fifteen urine specimens which were positive for HCMV by conventional virus culture were also amplified. Amplification products were analyzed by polyacrylamide gel electrophoresis. The products from PCR with primer IE were also identified by DNA blot hybridization. Results : PCR using primer IE gave the PCR products in all of the 15 HCMV wild strains. All of these were hybridized with probe IE. When primer MIE were used, 93%(14/15) of the wild strains showed amplified bands by direct gel analysis. When the urine specimens were amplified by PCR with primer IE, amplified bands were seen in 73%(11/15) by direct gel analysis ; 87%(13/15) by hybridization method. When primer MIE were used, 87%(13/15) of the urine specimens showed the PCR products by direct gel analysis. Conclusion : Polymerase chain reaction with primer IE and MIE may be a specific and sensitive diagnostic method for rapid detection of HCMV wild strains in Korea.

반도체 레이저의 온도 및 주입전류 의존성에 관한 연구

김의훈,김필수,이제형 漢陽大學校 基礎科學硏究所 1992 基礎科學論文集 Vol.11 No.-

반도체 레이저의 온도와 주입전류 변화에 따른 방출스펙트럼의 특성을 조사하고 파장조정 가능성을 연구하였다. 실온에서 피크파장 780nm를 가지는 Mitsubishi사의 GaAlAs계의 레이저 다이오우드에 대해 주입전류를 일정하게 유지하고 온도를 변화시켰을 때의 방출피크파장은 계단적으로 증가하였으며 파장의 의존도는 0.20nm/℃였다. 온도를 일정하게 유지하고 주입전류를 변화시켰을 때의 방출피크파장 역시 계단적인 변화양상을 보였으며 파장의 전류 의존도는 0.11nm/mA였다. 한편 레이저 다이오우드의 문턱전류는 다이오우드의 온도 증가에 따라 거의 지수함수적으로 증가하였다. 온도와 주입전류 변화로 얻은 최소 방출파장은 770nm이었다. Spectral characteristics and wavelength tunability of a semiconductor diode laser have been studied by examining the wavelength dependence on temperature and injection current. The results show that the output peak wavelength from a Mitsubishi GaAlAs laser diode increases stepwise with increasing temperature at constant injection current, showing the wavelength dependence on temperaure of 0.20nm/℃. On the other hand, the output peak wavelength also varies stepwise with increasing injection current at constant temperature, representing the wevelength dependence on injection current of 0.11nm/mA. The measured threshold currents of the diode laser increase exponentially as a function of temperature. By control of temperature and injection current of laser diode, the output peak wavelength can be attained down to 770nm.

초음파영상을 이용한 정상 교근의 평가

황형주,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.2

Purpose : To assess the internal echo intensity and morphological variability of masseter muscles on ultrasonography and to establish diagnostic criterion of estimation. Materials and Methods : Participants consisted of 50 young adults (male 25, female 25) without pathologic conditions and with full natural dentitions. Sonographic examinations were done with real time ultrasound equipment as Logiq 500 (GE Medical Systems, Seoul, Korea) at 3 parts according to lines paralleling with ala-tragus line as reference line. The thickness and area of masseter muscles according to reference line in cross-sectional images were measured at rest and at maximum contraction. The visibility and width of the internal echogenic intensity of the masseter muscles were also assessed and the muscle appearance was classified into 4 types. Data were statistically analyzed by paired t-test and x²-test. Results : 1. When comparing the thickness and area of masseter muscles concerning with gender, there was few significant difference between right and left sides, however, there were significant differences between males and females except for the greatest thickness of left side. 2. The changes of the greatest thickness and the area between rest and maximum contraction showed that the part of the least thickness manifested more increase at maximum contraction. 3. Each part the manifestations of the internal echogenic intensity of the masseter muscles were different depending on the locations. But there was no statistically significance. Conclusion : Changes of muscles thickness with contraction and internal echogenic intensity with locations showed great disparity within the masseter muscles, which will be diagnostic criteria for pathophysiologic and anatomic changes of masseter muscles.

강산 및 강알칼리 음독에서 냉각 용액을 사용한 희석 요법과 중화 요법의 가능성

이중의,송형곤,김동훈,권운용,곽영호,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: There is no effective treatment modality for caustic agent ingestion. Dilution and neutralization are prohibited because of the risk of secondary thermal injury. This experiment is designed to evaluate the amount of dilution and neutralization heat and to gauge the applicability of dilution and neutralization therapy using cold solutions to suppress the peak temperature. Methods: This is an in-vitro chemical experiment. HCl, CH3COOH, NaOH, and NH4OH are selected as representatives of strong and weak acids and strong and weak alkali, respectively. 20℃, 11.6M, 5.8M, and 2.9M solutions of each acid and alkali are made and mixed using a magnetic stirrer at a room air temperature of 28℃. The peak temperature, the duration above 40℃, and the heat amount are measured or calculated. Results: When a 11.6M HCl or NaOH solution is diluted with same amount of water, 32 or 18cal. per mL of HCl or NaOH is produced, respectively. HCl produces a significant peak temperature, but NaOH does not. The lower the concentration, the lower the amount of heat production. 11.6M CH3COOH and NH4OH solutions don't produce dilution heat.11.6M and 5.8M solutions of all acids and alkali produce destructive neutralization heat. However, 2.9M solutions produce neutralization heat which might be controllable. When a 11.6M HCl or NaOH solution is neutralized with a -10℃ 2.9 M NaOH or HCl solution, respectively, the peak temperature produced is below 40℃ and seems to add little thermal damage to viable tissue. Conclusion: Dilution and neutralization with a cold solution in cases of strong acid or alkali ingestion is a promising method to avoid thermal injury.

실험계획법을 이용한 대형 사출물의 사출성형 해석과 검증에 관한 연구

이형수,이희관,양균의 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis

골반부 방사선 치료 환자에서 in vivo 선량측정시스템의 임상적용

김보경,지의규,허순녕,이형구,하성환 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.1

방사선치료 시 종양에 정확한 양의 방사선을 조사하는 것은 국소 재발을 방지하고 합병증의 빈도를 낮춰 효과적인 치료를 가능하게 하는 중요한 요소이다. 종양에 조사되는 방사선량의 측정을 통해 치료의 정확성을 확인하기 위한 여러 방법들이 시도되고 있으며, 투과선량을 이용한 측정법도 그 중 한 예로 비침습적이며 매 치료 시 측정이 가능한 장점을 가지고 있다. 본 교실에서는 투과선량을 이용한 in vivo 선량측정시스템과 임의의 치료 조건에서 투과선량을 계산하기 위한 알고리즘을 개발하였다. 본 교실에서 개발한 in vivo 선량측정시스템의 단기간 및 장기간의 재현성을 확인하고, 환자의 방사선치료에서의 이용 시 발생할 수 있는 문제점을 파악하고 알고리즘의 정확성을 확인하기 위하여 본 연구를 시행하였다. 2000년 7월 25일부터 8월 14일 사이에 방사선치료를 시행 받은 환자 66명을 대상으로 투과선량의 측정을 시행하였으며, 이 중 골반부위의 방사선 치료를 3회 이상 시행 받은 11명의 환자를 대상으로 측정선량과 예측선량의 비교 분석을 시행하였다. 측정시스템의 재현성의 확인을 위하여 환자의 치료 전 및 치료 중 매시간 기준 조사조건에서 측정치를 확인하였다. 일별 몇 일 중 변동은 ±2% 이내로 재현성을 확인할 수 있었다. 본 시스템의 사용 시 별다른 문제점은 없었으나, 2명의 흉부 치료환자에서 투과선이 치료용테이블의 측면 금속을 관통하는 문제가 발생하였다. 골반부위 환자에서는 골반부위의 불균질조직에 의한 영향의 확인을 위하여, CT 및 simulation film을 이용하여 골 조직의 두께를 확인하여 보정 전 및 후의 값을 비교하였다. 전후방 및 후방조사야의 경우 골 조직의 보정을 시행하지 않은 경우 평균 오차가 -5.20%내지 +2.20%이었으며, 보정을 시행한 경우 -0.62%내지 +3.32%로 환자에 따라 정도의 차이는 있으나 골 보정이 필요함을 확인할 수 있었다. 측정치와 예측치 간 오차의 표준편차는 1.19%내지 2.46%로서 재현성이 높음을 확인할 수 있었다. 좌우 측방조사야에서 골 보정을 시행하지 않은 경우 평균오차는 -10.80%내지 +3.46%로서 골 조직의 보정이 필요하지 않은 1인의 환자를 제외하면 모두 음수 값을 지녔고, 보정을 시행한 경우 -0.55%내지 +3.50%의 평균오차를 지녀 골 보정의 필요성을 확인할 수 있었다. 측정치와 예측치 간 오차의 표준편차는 1.09%내지 6.98%로 전후방조사야의 경우보다 재현성이 낮음을 알 수 있었다. 복와위로 방사선치료를 시행 받은 환자의 경우를 제외하면, 표준편차는 1.09%내지 3.12%로 1례 외에는 2.57% 이내로 재현성이 높음을 확인할 수 있었다. 본 실험을 통하여 in vivo 선량측정시스템의 안전성과 재현성을 확인할 수 있었다. 정확한 예측치를 얻기 위하여 불균질 조직이 조사야에 포함되는 경우 보정이 요구되며, 골반의 경우 골 조직의 보정이 중요한 요인임을 알 수 있었다. 이를 위하여 불균질 조직에 대한 정확한 정보가 요구되며, 이는 CT 영상을 이용하는 것이 크게 도움이 되리라 생각된다. The accuracy of radiation dose delivery to target volume is one of the most important factors for good local control and less treatment complication. In vivo dosimetry is an essential QA procedure to confirm the radiation dose delivered to the patients. Transmission dose measurement is a useful method of in vivo dosimetry and it's advantages are non-invasiveness, simplicity and no additional efforts needed for dosimetry. In our department, in vivo dosimetry system using measurement of transmission dose was manufactured and algorithms for estimation of transmission dose were developed and tested with phantom in various conditions successfully. This system was applied in clinic to test stability, reproducibility and applicability to daily treatment and the accuracy of the algorithm. Transmission dose measurement was performed over three weeks. To test the reproducibility of this system, X-ray output was measured before daily treatment and then every hour during treatment time in reference condition (field size; 10 cm x 10 cm, 100 MU). Data of 11 patients whose pelvis were treated more than three times were analyzed. The reproducibility of the dosimetry system was acceptable with variations of measurement during each day and over 3 week period within ±2.0%. On anterior- posterior and posterior fields, mean errors were between -5.20% and +2.20% without bone correction and between -0.62% and +3.32% with bone correction. On right and left lateral fields, mean errors were between -10.80% and +3.46% without bone correction and between -0.55% and +3.50% with bone correction. As the results, we could confirm the reproducibility and stability of our dosimetry system and its applicability in daily radiation treatment. We could also find that inhomogeneity correction for bone is essential and the estimated transmission doses are relatively accurate.

파라콰트 중독에서의 항산화치료

권운용,조유환,송형곤,김명천,이중의,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Paraquat causes severe tissue toxicity when ingested, but has no effective treatment modality. We have shown that high dose vitamin C has effective antioxidant activities against the paraquat intoxication in a previous animal experiment. This study was designed to evaluate the effect of antioxidant therapy with high dose vitamin C and vitamin E in human cases of paraquat intoxication. Methods: From August 1999 to August 2001, 19 paraquat intoxication patients who visited the emergency department of the Seoul National University Hospital and the Kyounghee University Hospital were enrolled to this study. They were devided into two groups, a control group(9 patients) and a study group(10 patients). The control group received only conservative managements including gastro-intestinal decontaminati-on. The study group received conservative managements plus the antioxidant therapy which was composed of vitamin C 24 gm/day intravenously and 20 gm/day orally, and vitamin E 1.6 gm/day orally. Results: In the study group, 5 of 10 patients(50%) survived, but all patients of the control group died(p=0.003). There were no significant differences in age, sex, and usage of gastric lavage and activated charcoal between the two groups. Difference in ingested amount of paraquat between the two groups could not be analyzed due to the inexact and subjective measuring methods based on patients' histories. Conclusion: Antioxidant therapy with high dose vitamin C and vitamin E is effective in vival rate in paraquat intoxicated patients.

사판식 유압피스톤 펌프ㆍ모터의 해석 및 설계

현동수,이용범,김형의 大田産業大學校 2000 한밭대학교 논문집 Vol.17 No.1

Since the swash plate type axial piston pump/motor utilizes hydrostatic bearings between the surfaces of fixed and moving parts in the design. it becomes not only high pressurized but also high efficient, and it is thus used in many fields that require the high speed and the high power per unit weight - mobility equipments, concrete mixer drums, tractors. military products etc. The swash plate type axial piston pump/motor is characterized by high power per unit weight, power transmission, and easy operation. but relatively big power loss, and sensitivity to contaminated operating oil are taken into consideration disadvantages over others. With the design consisting of very precise and complicated parts its performance truly varies depending on manufacturing and assembly techniques in the production. In this study, analytical approaches and power loss mechanisms are proposed for the in-line integrated Hydrostatic Transmission(HST) with variable hydraulic piston pump and fixed hydraulic piston motor in order to improve performance. To this end, first, analytical model and characteristics on the piston show and shoe plate from basic theories in hydraulic pump/motor are presented, and volumetric and mechanical losses are further investigated.

119구급대를 통한 서울지역 외상환자 진료체계에 대한 통계분석

서길준,이승한,조익준,권운용,송형곤,이중의,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.2

Backgroud: Despite continous efforts to improve the prehospital trauma care system in Korea, the preventable death rate has been reported to be high. The purpose of this study was to evaluate the prehospital trauma care system in Seoul by analyzing 119 rescue databases. Methods: The 119 rescue data bases of 22,275 trauma patients, who were transported to the secondary and tertiary hospital in Seoul by Seoul 119 rescue services from January 1, 2000 to December 31, 2000, were analyzed. Results: The response time(mean 3.7 min.) showed no time, weekly, and regional variations. However, the transport time from field to hospital showed was high in the morning rush hour(7:00 to 10:00 am), and was gradually decreased and the lowest between 10:00 pm and 7:00 am. There was also a regional variation in the transport time, which was short in the central area and long in the peripheral area of Seoul. Prehospital cares were given to the 10,999 trauma patients(49.4%). Of the 464 unresponsive patients(2%), only 236 patients were identified in transported hospitals. The outcomes of these unresponsive patients were DOA(54%), survival(19%), death in ER(14%), transfer to other hospitals(8%), and death after admission(5%) in order. Conclusion: We suggest that this study may be helpful to the establishment and improvement of the prehospital trauma care system as well as the determination of the adequate numbers and locations of trauma center in Seoul.