방사선조사가 Porphyromonas gingivalis에 미치는 영향

이창환,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.1

Purpose : The aim of this study was to observe a direct effect of irradiation on the periodontopathic Porphyromonas gingivalis (P. gingivalis). Materials and Methods : P. gingivalis 2561 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Changes in viability and antibiotic sensitivity, morphology, transcription, and protein profile of the bacterium after irradiation were examined by pour plating method, disc diffusion method, transmission electron microscopy, RT-PCR, and immunoblot, respectively. Results : Viability of irradiated P. gingivalis drastically reduced as irradiation dose was increased. Irradiated P. gingivalis was found to have become more sensitive to antibiotics as radiation dose was increased. With observation under the transmission electron microscope, the number of morphologically abnormal cells was increased with increasing of irradiation dose. In RT-PCR, decrease in the expression of fimA and sod was observed in irradiated P. gingivalis. In immunoblot, change of profile in irradiated P. gingivalis was found in a number of proteins including 43-kDa fimbrillin. Conclusion : These results suggest that irradiation may affect the cell integrity of P. gingivalis, which is manifested by the change in cell morphology and antibiotic sensitivity, affecting viability of the bacterium.

활성탄에서 할로카본의 흡착 평형

장원철,임진규,이태진 嶺南大學校 環境問題硏究所 1994 環境硏究 Vol.13 No.2

두가지 활성탄에 대한 4가지 할로카본(CFC-113, CFC-11, Methylene Chloride, 1,1,1-TCE)의 흡착평형을 용량법으로 473K의 진공에서 밤새 처리한 후에 298-473K에서 측정하였다. Clausius-Clapeyron식으로 구해진 흡착열은 Henry's law constants로 구한 흡착열과 같은 크기의 정도(order of magnitude)를 보였으며 표면점유율에 상관없이 거의 일정하였다. 실험측정치를 BET상관식, Langmuir식, Dubinin-Astakhov식으로 해석하였으며 흡착제의 변수를 결정하였다. Dubinin-Astakhov식의 지수 n은 1.2∼2.7의 범위를 보였으며 이 값들은 흡착질과 흡착제간의 상호 작용의 의존도를 보여주었다. 흡착특성에너지 E와 지수 n은 흡착질의 분자직경 d에 의해 상관 관계를 맺을 수 있었다. Adsorption equilibria of four kinds of Halocarbons(CFC-113, CFC-11, Methylene Chloride, 1,1,1-TCE) on two activated carbons were measured at 298-473 K by using a static adsorption apparatus. The adsorbents were regenerated overnight at 473K under vacuum condition. The heat of adsorption calculated from Clausius-Clapeyron equation and that obtained from Henry's law constants showed the same order of magnitude. And it remained nearly constant irrespective of the surface coverage. Experimental data were correlated by BET, Langmuir, and Dubinin-Astakhov equations with the parameters of the adsorbents. The exponent n in Dubinin-Astakhov equation ranged from 1.2 to 2.7 depending on the adsorbate-adsorbent system. The characteristic energy of adsorption E and the exponent n were correlated by the molecular diameter d of the adsorbate.

텔레스코픽 크라운 임플란트 지지 피개의치와 치아 지지 피개의치의 하악골내 응력분포에 관한 유한요소분석

이창규,백장현,김태훈,김민정,김형섭,권긍록,우이형 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

PURPOSE. The purpose of this study was to investigate the stress distribution in mandibular implant-supported overdentures and tooth-supported overdentures with telescopic crowns. MATERIALS AND METHODS. The assumption of this study was that there were 2, 3, 4 natural teeth and implants which are located in the second premolar and canine regions in various distributed conditions. The mandible, teeth (or implants and abutments), and connectors are modeled, and analyzed with the commercial software, ANSYS Version 10.1. Stress distribution was evaluated under 150 N vertical load bilaterally on 3 experimental conditions - between canine areas, canine and 2nd premolars, 10 mm posterior to 2nd premolars. RESULTS. Overall, the case of the implant group showed more stress than the case of the teeth group in stress distribution to bone. In stress distribution to superstructures of tooth and implants, there was no significant difference between TH group and IM group and the highest stress appeared in TH-IV and IM-IV. The stress caused from bar was much higher than those of implant and tooth. TH group showed less stress than IM group in stress distribution to abutment teeth and implant. CONCLUSION. The results shows that it is crucial to make sure that distance between impact loading point and abutment tooth does not get too far apart, and if it does, it is at best to set abutment tooth on premolar tooth region. It will be necessary to conduct more experiments on effects on implants, natural teeth and bone, in order to apply these results to a clinical treatment. 연구 목적: 이 연구의 목적은 텔레스코픽 크라운 하악 임플란트 지지 피개의치와 치아 지지 피개의치에서 지대치의 수와 위치에 따른 응력 분산을 비교하기 위함이다. 연구 재료 및 방법: 본 연구에서는 임플란트를 4개 식립하고 임플란트 지지 피개의치로 설계하였고, 식립 위치를 견치와 소구치 부위에 위치 별로 3개 또는 2개 존재시를 실험군으로 설정하였다. 자연치아를 갖는 경우도 견치와 제2소구치 4개를 가진 경우를 대조군으로 설정하고 부위별로 3개 또는 2개를 가지는 경우를 실험군으로 설정하였다. ANSYS Version 10.1 (Swanson, Inc., USA)로 분석하였다. 결과: 악골내 응력의 경우, 전반적으로 임플란트(IM)로만 구성된 경우가 치아(TH)로만 구성된 경우에 비해 응력이 크게 발생하였다. 상부구조의 경우, 치아군(TH)과 임플란트군(IM) 사이의 차이는 크게 없었으며 편측 견치와 제2소구치에 지대치 또는 임플란트가 위치하는 경우 가장 큰 응력이 나타났고 바(bar)에서 발생된 응력이 임플란트와 치아에서 발생되는 응력에 비해 상대적으로 훨씬 크게 발생하였다. 지대치와 임플란트의 경우, 치아군(TH)이 임플란트군(IM)보다 응력이 작게 발생하였다. 결론: 본 연구의 결과로부터 지대치(임플란트 또는 치아)를 설정할 때는 하중작용점과 지대치 사이의 거리가 너무 길어지지 않도록 지대치의 수와 위치를 확보해야 하며 소구치 자리에 지대치를 확보하는 것이 유리하다. 앞으로, 실제 임상에 적용하였을 경우, 임플란트 및 자연치아와 악골에 미치는 결과에 대한 연구가 더 필요할 것으로 생각된다.

DS-CDMA 시스템 적용을 위한 Smart Antenna 기술

장태규,김종윤,김재화 중앙대학교 정보통신연구소 1999 정보통신연구소논문집 Vol.1 No.1

본 연구에서는 fading 및 공간적인 scatter를 고려한 전파환경 모델을 제시하고, CDMA 수신기능 블록들을 포함한 beamforming 알고리즘의 동작 시뮬레이션을 수행하였다. MVDR 및 steering-only beamforming 알고리즘을 적용하여 위치추정 기능 및 계수 최적화기능에 대한 성능 및 오차영향을 개별적으로 분석하도록 하였다. Beamforming의 성능 지표인 SINR에 대한 해석식을 유도하고 이를 동작시뮬레이션을 통하여 얻은 SINR 결과와 비교 제시함으로서 본 연구에서 구현한 beamforming 안테나 동작 시뮬레이션과 해석의 타당성을 확인하였다.

한국인 쯔쯔가무시병 환자에서 사이토카인 유전자의 다양성 조사

장우임,김수연,위성헌,김태규 대한감염학회 2010 감염과 화학요법 Vol.42 No.1

Background: Scrub typhus is caused by Orientia tsutsugamushi and can become severe and potentially life-threatening. It is suggested that specific host factors can modify the host response during O. tsutsugamushi infection. It is known that susceptibility and outcome of infectious disease are associated with genetic polymorphisms of some cytokines. Materials and Methods: Peripheral blood of 144 patients who were diagnosed with scrub typhus and of 311 unrelated healthy subjects were collected. A diagnosis of scrub typhus was made upon demonstration of a fourfold rise in antibody titer to O. tsutsugamushi in paired serum specimens in an indirect immunofluorescent (IFA) test. Genomic DNAs were extracted from peripheral mononuclear cells and genotypings for IL-1 (-511C/T), IL-1β (+3953T/C), IL-2 (-330T/G), IL-4 (-590C/T), IL-4R(-1902G/A), IL-10 (-1082G/A), IL-10 (-819C/T), TNF-α (-238G/A) and TNF-α (-308G/A) were performed simultaneously using PCR-SSP (sequence specific polymorphisms) assay. Results: The frequency of IL-1 (-511T/T) (OR=0.53, P<0.01) and IL-2 (-330T/T) (OR=0.56, P<0.01) were significantly decreased, but that of IL-2(-330G/G) (OR=4.49, P<0.01) was increased, in the scrub typhus patients compared to the healthy controls. And, there were no statistically significant differences in the genetic polymorphisms of IL-4 (-590C/T), IL-4Rα (-1902G/A), IL-10 (-1082G/A), IL-10 (-819C/T), TNF-α (-238G/A), TNF-α (-308G/A) genes, in the scrub typhus patients compared to the unrelated healthy controls. Conclusions: Cytokine polymorphisms in the IL-1 (-511T/T) and the IL-2 genes may influence the host response to O. tsutsugamushi.

열처리 개선을 통한 전동 공구 Gear류의 수명 향상에 관한 연구

이창순,임태환,박인규 선문대학교 중소기업기술지원연구소 1997 선문공대 연구/기술 논문집 Vol.2 No.1

다물체 동역학 모델을 이용한 밸런싱 방법에 관한 연구

지창진,유태규,홍성욱 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

Aysmmetric rotors are often employed in a variety of machines. A large amount of asymmetry in rotors makes the conventional balancing schemes very difficult in implementation. In this paper, a balancing scheme which systematically adjusts principal inertial axes by adding balancing weights is applied. A multi-body dynamic model using commercial codes, ADAMS and SIMULINK, is developed to prove the effect of balancing in a heavily unbalanced rotor.

한랭노출과 고혈압의 연관성

장태원,김윤규,윤동영,이창희,홍영습,신해림,정갑열,김준연 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.4

Objectives : This study was carried out to suggest preventive methods for hypertension in cold-exposed workers. Methods : In 11 refs·iteration industries, 68 workers working in refrigerated areas more than one time per day were selected as the exposed group, and 68 workers not exposed to cold were selected as the control group. We interviewed the subjects with a questionnaire covering occupational history, and conducted clinical and laboratory tests including measurements of blood pressure and core temperature. Results : The systolic blood pressure in the exposed group(130.0±13.3 mmHg) was significantly higher than that recorded In the control group(118.3±12.1 mmHg), as was the diastolic blood pressure in the exposed group(82.7±8.5 mmHg) versus the control group(77.4±8.7 mmHg). The core temperature in the exposed group(36.1±0.7℃) was significantly lower than that experienced in the control group (36.4±0.5℃). In logistic regression analysis, age, cold exposure severity and milk intake were significant variables, with odds ratios of 5.204(95 % CI 1.440∼18.812), 2.674(95 % CI 1.080∼6.618), and 0.364(95 % Cl 0.141∼0.942) , respectively. Conclusions : Our study suggests that cold-exposed workers have higher a higher risk of hypertension, and that their core temperature is lower. Risk factors affecting hyper-tension of cold-exposed workers include age, cold exposure severity and milk intake. For the prevention of hypertension, cold-exposed workers should minimize cold-exposure time as much as possible.

中風 動物 모델의 運動機能失調에 對한 硏究

洪茂昌,申玟圭,禹太律 慶熙大學校韓醫科大學韓醫學硏究所 1999 慶熙韓醫大論文集 Vol.22 No.1

We induced brain ischemia using middle cerebral artery occlusion(MCAo) and studied the results of walking initiation and circling test, posture reflex test, water bath swimming test to characterize the motor dysfunction and establish the model of stroke by MCAo for oriental medicine. Analysis of total rotation angle during 1 min. swimming showed significant motor dysfunction in occlusion group(3hrs, 6hrs, 9hrs, 24hrs after MCAo). Analysis of rectal rotation number during 1 min. swimming showed significant difference between control group and occlusion group(3hrs, 6hrs, 9hrs, 24hrs after MCAo). Analysis of posture reflex test showed significant difference between control group and occlusion group(3hrs, 6hrs, 9hrs, 24hrs, after MCAo). Significant motor dysfunctions are shown at start time in 24hrs, at inner circle time and outer circle time in 9hrs, 24hrs, at contalaterl or ipsilateral circling number or 180°turn in 3hrs, 6hrs, 9hrs, 24hrs during walking initiation and circling test. Results revealed that brain ischemia by intraluminal method was good at stroke model for oriental medicine which chiefly reveals motor dysfunction by paralysis of one side and behavior index suggested in this article could be used as a useful index for assessment of motor dysfunction.

분말야금법에 의해 제조된 소결 GEAR 및 RATCHET의 조직 특성

임태환,이창순,박인규 선문대학교 중소기업기술지원연구소 1997 선문공대 연구/기술 논문집 Vol.2 No.1