유한요소법에 의한 골강도와 micro-CT 지표 및 골밀도간의 상관관계

윤영남,이완,이병도 대한구강악안면방사선학회 2007 Imaging Science in Dentistry Vol.36 No.1

Purpose : Bone mineral density (BMD) and bone microarchitecture are important determinants for bone strength. Recently micro-CT have provided possibilities for measuring a variety of structural indices to characterize bone microarchitecture. The objective of this study was to compare the BMD and micro-CT parameters with Young's modulus calculated by finite element analysis(FEA) for the evaluation of bone strength. Materials and Methods : Bone specimens were obtained from the 18 female rabbits aged 16 weeks. Of those, 36 samples (right and left femur) were selected for 3D micro-CT analysis (ANT^(TM), SKYSCAN, Belgium) and BMD by PIXImus 2 (GE Lunar Co. USA). Five microstructural parameters of micro-CT, such as trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DOA) were studied. Young's modulus was obtained by software program (ANSYS 9.0, ANSYS Inc, Canonsburg, PA) based on micro-CT three dimensional images. Results : Young's modulus assessed by FEA correlated significantly with Tb.Th, BV/TV, BS/BV and SMI respectively. Young's modulus showed higher correlation with these microstructural parameters of micro-CT than BMD. Microstructural parameters except DOA showed significant correlations within the examined group. Conclusion : The microarchitectural parameters of micro-CT and BMD represented some informations in the evaluation of bone strength assessed by FEA. (Korean J Oral Maxillofac Radiol 2007; 37: 53-9)

IL-1 수용체를 통한 T세포 활성화에 Genistein 과 Staurosporin이 미치는 영향

한미영,윤도영,오은숙,고우석,윤선영,정태화 大韓免疫學會 1996 大韓免疫學會誌 Vol.18 No.4

Stimulation of T-cells through TCR/CD3 complex alone is known to be not enough but also require a costimulatory signal, such as IL-1 stimulation. to induce IL-2 production. In this report, we studied the differential effects of staurosporin (a PKC inhibitor) and genistein (a PTK inhibitor) on the IL-2 production by EL-4 and A2.5 cells, to determine which pathway is responsible for IL-1 receptor signal transduction. While staurosporin suppressed the IL-2 production induced in EL-4 cells upon PMA stimulation but not upon PHA plus IL-1, genistein inhibited the IL-2 production induced by PHA plus IL-1 but not by PMA. Genistein also completey abrogated the IL-2 production by A2.5 cell when stimulated with PHA and IL-1. These results suggest that the costimulatory signal by IL-1, which leads to IL-2 production and proliferation, is closely linked to the PTK activity in T cells.

유한요소법에 의한 골강도와 micro-CT 지표 및 골밀도간의 상관관계

윤영남,이완,이병도,Yoon, Young-Nam,Lee, Wan,Lee, Byung-Do 대한영상치의학회 2007 Imaging Science in Dentistry Vol.37 No.1

Purpose : Bone mineral density (BMD) and bone microarchitecture are important determinants for bone strength. Recently micro-CT have provided possibilities for measuring a variety of structural indices to characterize bone microarchitecture. The objective of this study was to compare the BMD and micro-CT parameters with Young's modulus calculated by finite element analysis (FEA) for the evaluation of bone strength. Materials and Methods Bone specimens were obtained from the 18 female rabbits aged 16 weeks. Of those, 36 samples (right and left femur) were selected for 3D micro-CT analysis $(ANT^{TM},\;SKYSCAN,\;Belgium)$ and BMD by PIXlmus 2 (GE Lunar Co. USA). Five microstructural parameters of micro-CT, such as trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DOA) were studied. Young's modulus was obtained by software program (ANSYS 9.0, ANSYS Inc, Canonsburg, PA) based on micro-CT three dimensional images. Results : Young's modulus assessed by FEA correlated significantly with Tb.Th, BV/TV, BS/BV and SMI respectively. Young's modulus showed higher correlation with these rnicrostructural parameters of micro-CT than BMD. Microstructural parameters except DOA showed significant correlations within the examined group. Conclusion The microarchitectural parameters o( micro-CT and BMD represented some informations in the evaluation of bone strength assessed by FEA.

활막육종

김재도,윤영민,손정환,홍영기,손영찬,박정호,Kim, Jae-Do,Yoon, Young-Min,Son, Jeong-Whan,Hong, Young-Gi,Son, Young-Chan,Park, Jeong-Ho 대한근골격종양학회 1996 대한골관절종양학회지 Vol.2 No.1

Synovial sarcoma is an uncommon malignant soft tissue tumor which usually occurs in young-aged person, and frequently involves the lower extremities. Many authors recommended wide excision, adjuvant chemotherapy and radiation therapy. The proposed factors that affect the prognosis are age, size of tumor, site of tumor in the body, depth of tumor, histologic grade and method of treatment. The purpose of the study is to analyze the factors that affect the 5-year survival rate. We retrospectively evaluated 19 cases of synovial sarcoma treated in the Kosin University Medical Center from Jan. 1982 to Dec. 1994. The overall 5-year survival rate was 47.6% and the 5-year survival rates were significantly higher(P<0.05) in the group with smaller size of mass. The significantly lower 5-year survival rates were observed in the patient with deeply located lesion and with higher histologic grade. The 5-year survival rates were higher in the patients treated with wide excision than in the patients treated with amputation. But there was no significant difference between these groups. The adjuvant chemotherapy and radiotherapy were performed. In conclusion, we suggest that the better prognosis will be observed in the patients with smaller size of tumor mass, superficially located and lower histologic grade.

전기도금계에서 유발되는 자연대류에 의한 물질전달 특성

윤도영,조규택,송항옥 光云大學校 1995 論文集 Vol.24 No.-

In the present study, onset conditions and transfer characteristics have been investigated experimentally through electrochemical technique. Cupric sulfate-sulfuric acid solution confined between two horizontal copper electrodes was used. The magnitude of current estimating transfer rate was measured at an adopted constant electrical potential. Due to the change of the polarity of electrodes, the diffusion and natural convection have been induced respectively. The dimensionless onset time and correlation equations were as follows. r=70.57Ra-? Sh=0.04731Fa? Above results have differences comparing with existing data which ignore the electrical migration effects. It is considered that the difference between ours and others comes from the effects of migration which we have applyed quantatively. Also, it is ween that the electrical migration not only retards the onset of natural convection, but reduces the transfer rates.

저압 MOCVD반응기에서 ZnO박막의 화학증착에 대한 CFD해석

윤도영 광운대학교 신기술연구소 1999 신기술연구소논문집 Vol.28 No.-

본 연구에서는 저압 유기금속 화학증착 반응기내에서 DEZ(diethyl zinc)의 증착반응 및 유동현상을 POLYFLOW를 이용한 전산유체역학(CFD)의 해석결과로부터 산출하여 최적의 산화아연박막의 증착조건을 도출하였다. 전제방출디스플레이(FED)로 활용가능한 산화아연박막의 제조공정에서 반응물로는 DEZ, 산화제와 운반가스로는 산소가스와 질소가 각각 적용되었다. 유한요소법에 기초한 POLYFLOW는 화학증착반응기내에서 화학증기와 같은 열유체의 이동현상을 해석하는데 있어 효과적인 것으로 나타났다. 특히 계산결과에 의하면 증착속도에 대하여 기판의 온도영향이 주요한 변수로 작용하고 있었으며, 최적의 증착조건으로부터 비교적 균일한 표면적 두께를 조절할 수 있을 것으로 기대된다. The present study investigates the optimal condition for the deposition of ZnO:Zn thin film using POLYFLOW to solve the deposition reaction and flow phenomenon of diethyl zinc vapor in a M0CVD (Metal Organic Chemical Vapor Deposition) reactor. The manufacturing process of zinc oxide thin film for the use of Field Emission Display involves diethyl zinc(DEZ) as a reactant, oxygen gas as an oxygenic agent and nitrogen gas as a carrier gas. POLYFLOW which is a commercial simulator for Computational Fluid Dynamics based on finite element method was very effective to analyze the transport phenomena of thermal fluids like chemical vapors. The computational results show that the temperature plays an important role in the deposition rate. Therefore it is expected that the optimal condition of temperature controls the uniformity of deposition thickness.

개 대뇌겉질에서 Platelet-Derived Growth Factor α-Receptor의 출생 후 발달에 관한 면역조직화학적 연구

윤영,안병수,김인정,양경철,박선홍,김기훈,박도영,김장만,문정석,장인엽,조하영 조선대학교 부설 의학연구소 2002 The Medical Journal of Chosun University Vol.27 No.1

Background and Objectives : The localization of platelet-derived growth factor-α receptor (PDGF-α R) was commonly restricted to oligodendrocyte progenitors during late embryonic and postnatal development. However, several studies recently demonstrated that mature neurons could also synthesize PDGF-α, Materials and Methods : In the present study, to analyze the distributional pattern of PDGF-αR during postnatal development of the canine cerebral cortex, we used immunohistochemistry on sections of canine brain tissue. Results : We found that neurons of various regions of cerebral cortex exhibited the immunoreactivity to PDGF-αR as early as postnatal day 0, and slightly decreased after postnatal day 14. Whereas neuronal PDGF-αR were maintained at all ages, the oligodendroglia-like expression of PDGF-αR could not be confirmed. Conclusion : The localization of PDGF-αR in immature and mature neurons supports the several roles of PDGF during development, protection and survival of neurons.

동시에 진단된 대장암·위암 중복암 2예

신영도,이상목,이기형,윤충 대한대장항문학회 1996 Annals of Coloproctolgy Vol.12 No.3

마이크로 프로세서에 의한 自己制御형 永久磁石 同期 電動機의 驅動 및 運轉 特性의 改善

윤병도,김윤호,김일환,이용석 중앙대학교 기술과학연구소 1989 기술과학연구소 논문집 Vol.19 No.-

전력 전자 공학의 발달에 의해 영구자석 동기전동기의 운전 분야가 대단히 진보되고 있음이 최근 논문을 통해서 보고 되고 있다. 영구자석 동기전동기는 크기와 중량의 감소로 인한 장점, 회전자의 동손이 없으므로 효율이 높다는 장점이 있어 각종 분야의 응용에 유리하다. 본 연구는 마이크로프로세서와 전압원 인버터를 사용한 자기제어형 영구자석 동기전동기의 구동장치를 제안한다. 영구자석 동기전동기의 운전은 고정자 전류와 역기전력을 동기화 시킴으로서 가능하게 한다. 고 분해능의 인크리멘탈 엔코더를 사용하여 영구자석 동기전동기에 적합한 자기제어형 PWM. 인버터 설계를 가능하게 하였다. 저속 영역에서 토오크 리플을 감소 시키기 위해 펄스 수를 제어하였으며 운전중 최적 부하각의 제어는 토오크-속도 특성을 개선시킴을 검토 하였다. Recent research has indicated that the permanent magnet synchronous motor(PMSM) drives are considerably improved by the development of power electronics. The PMSMs are favoured in many applications as there are advantages in size and weight reduction, and in efficiency due to elimination of the field copper losses. This paper presents a Self-Controlled PMSM, fed by voltage suource inverter based on the microprocessor. The proper operation of the PMSM can be ensured only if the stator current is always synchronized with is Back-EMF. The use of incremantal encoder with high resolution makes it possible to design a Self-Controlled PWM inverter for a PMSM. The pulse ratios are controlled to reduce the torque ripple in the low-speed drive region. In addition, torque-speed characteristics are improved by the control of optimal load angle.

수면단계 및 체위에 따른 수면무호흡의 빈도 및 정도에 관한 연구

윤인영,정도언,민양기 大韓神經精神醫學會 1995 신경정신의학 Vol.34 No.4

Among the factors determining severity and frequency of obstructive sleep apnea sysdrome(OSAS), sleeping position and sleep stages seem to be crucial ones, supported by patients' & spouses' reports and clinical observations. This study was done to elaborate on the possible differences in the frequency and the severity of OSAS between supine and lateral positions as well as between REM and NREM sleep stages. Fourteen patients with clinical diagnosis of OSAS were studied polysomnographically for one full night using Oxford Medilog SAC 847 system. Standardized procedures were adopted for sleep recording with the body position sensor placed on the chest at the midline. Obtained computer-scored data were manually corrected regarding sleepstages, apnea types and the presence of arousals. IN the lateral position, compared with the supine position, respiratory disturbance index(RDI), O₂ desaturation and the percent arousals all decreased and the mean of lowest O₂ saturations increased significantly. During REM sleep, in comparison with NREM sleep, RD duration was more prolonged with O₂ desaturation more pronounced. The severity and the frequency of respiratory disturbances are more marked in the supine position and REM stage than in the lateral position and NREM stage respectively. Sleeping position training should be encouraged as an adjunctive therapeutic option, in addition to the adoption of other therapeutic maneuvers.