Simvastatin이 골결손부 회복에 미치는 영향

강정호,김규태,최용석,이현우,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.3

Purpose : To observe and evaluate the effects of Simvastatin-induced osteogenesis on the wound healing of defective bone. Materials and Methods : 64 defective bones were created in the parietal bone of 32 New Zealand White rabbits. The defects were grafted with collagen matrix carriers mixed with Simvastatin solution in the experimental group of 16 rabbits and with collagen matrix carriers mixed with water in the controlled group. The rabbits were terminated at an interval of 3, 5, 7, and 9 days, 2, 4, 6, and 8 weeks after the formation of defective bone. The wound healing was evaluated by soft X-ray radiography. The tissues within defective bones were evaluated through the analysis of flow cytometry for the manifestation of Runx2 and Osteocalcin, and observed histopathologically by using H-E stain and Masson’s trichrome stain. Results : 1. In the experimental group, flow cytometry revealed more manifestation of Runx2 at 5, 7, and 9 days and Osteocalcin at 2 weeks than in the controlled groups, but there was few difference in comparison with the controlled group. 2. In the experimental group, flow cytometry revealed considerably more cells and erythrocytes at 5, 7, and 9 days in comparison with the controlled group. 3. In the experimental group, soft x-ray radiography revealed the extended formation of trabeculation at 2, 4, 6, and 8 weeks. 4. Histopathological features of the experimental group showed more fibroblasts and newly formed vessels at 5 and 7 days, and the formation of osteoid tissues at 9 days, and the newly formed trabeculations at 4 and 6 weeks. Conclusion : As the induced osteogenesis by Simvastatin, there was few contrast of the manifestation between Runx2 and Osteocalcin based on the differentiation of osteoblasts. But it was considered that the more formation of cells and erythrocytes depending on newly formed vessels in the experimental group obviously had an effect on the bone regeneration.

삼상 순환 유동층 생물반응기에서 열전달 계수

강태규,송평섭,최길수,조용준,강용,최호석,김상돈 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.5

직경이 0.102m이고 높이가 1.0m인 기체-액체 순환 및 삼상 순환유동층 생물반응기의 상승관에서 열전달 특성을 고찰하였다. 기체 및 액체의 유속 그리고 생물막 담체의 체류량이 상승관 내부의 수직 열원과 반응기 사이의 열전달 계수에 미치는 영향을 결정하였다. 기체-액체 순환 반응기에서 열전달 계수는 기체의 유속이 증가함에 따라 증가하였으나 액체 유속의 증가에 따라서는 약간 증가하였다. 삼상 순환유동층 생물반응기에서 열전달 계수는 기체의 유속과 유동 생물막 매체의 체류량이 증가함에 따라 증가하였으나 액체의 유속이 증가함에 따라서는 약간 증가하였다. 본 연구의 실험 범위에서 이들 열전달 계수는 실험 조작 변수의 상관식으로 잘 나타낼 수 있었다. Heat transfer characteristics have been investigated in the riser of gas-liquid circulation and three-phase circulating fluidized-bed bioreactors whose diameter and height are 0.102m and 1.0m, respectively. Effects of gas and liquid velocities and holdup of fluidized biofilm media on the heat transfer coefficient between the immersed vertical heater and the bed have been determined. The heat transfer coefficient in the gas-liquid circulation reactor increases with increasing gas velocity, but increases only slightly with increasing liquid velocity. The h(heat transfer coefficient) value in the three-phase circulating fluidized-bed bioreactor also increases with increasing gas velocity or holdup of fluidized biofilm media, but it increases only slightly with liquid velocity. The value of heat transfer coefficient has been well correlated in terms of operating variables.

Cone beam형 전산화 단층영상을 이용한 하악전치부 영양관의 연구

강정호,김규태,최용석,황의환 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.36 No.3

Purpose : To evaluate location, distribution, diameter, and length of the nutrient canals on mandibular anterior region using a cone beam computed tomography (CBCT). Materials and Methods : Mandibular CBCT was performed on 33 adults (18 males and 15 females) with no history of systemic disease, and any other dental surgery history. Location, distribution, diameter, and length of the nutrient canals on mandibular anterior region were radiographically evaluated. A statistical comparison was done by SPSS. Results : In the location and distribution of nutrient canals, they were found in 6.8% at labial portion above root apex, in 93.28% at lingual portion above root apex in 46.2% at labial portion below root apex, and in 53.6% at lingual portion below root apex. Nutrient canals at lingual portion above root apex were most frequently observed between central and lateral incisors, and those at labial and lingual portion below root apex were most frequently observed between central incisors. The mean diameters of nutrient canals were 0.54 mm at labial portion above root apex, 0.61 mm at lingual portion above root apex, 0.66 mm at labial portion below root apex, and 0.76 mm at lingual portion below root apex. The mean lengths of nutrient canals were 2.63 mm at labial portion above root apex, 3.74 mm at lingual portion above root apex, 4.51 mm at labial portion below root apex, and 6.77 mm at lingual portion below root apex. Conclusion : CBCT is useful device to evaluate the anatomical structure of nutrient canals on mandibular anterior region.

플루옥세틴 캅셀제의 지원자에 대한 생체이용율 및 대사율 비교

강원구,박용순,조규행,최준식,권광일 충남대학교 약학대학 의약품개발연구소 1998 藥學論文集 Vol.14 No.-

Fluoxetine is a nontricyclic antidepressant which blocks serotonin reuptake selectively. Its N-demethyl metabolite, norfluoxetine is also selective inhibitor of serotonin uptake. This study was carried out to compare the bioavailability of Myung-in fluoxetine (20 ㎎/cap with that of Prozac?. The bioavailability was conducted on 24 healthy volunteers who received a single dose (80 ㎎) of each drug in the fasting state, in a randomized balanced 2-way crossover design. After dosing, serial blood samples were collected for a period of 48 hours. plasma was analyzed for fluoxetine and norfluoxetine by a sensitive and validated HPLC assay. The major pharmacokinetic parameters (AUC_0-48hr, Cmax, Tmax. AUC_inf.. MRT. T_1/2. Vd and Cl) were clculated from the plasma fluoxetine concentration-time data of each volunteer. The microcomputer program. "WinNonlin' was used for compartmental analysis. A two-compartment model with first-order inpot, first-order output and no lag time was chosen as the most appropriate phamacokinetic model. The data were best described by using a weighting factor of 1/y^2. Though the plasma fluoxetine concentrations of Myung-in fluoxetine were higher than those of Prozac® at all observed time from 7.9% to 16.9% (P<0.05 at 6, 7 and 10 hr), the bioavailability of Myung-in fluoxetine appeared to be bioequivalent with that of Prozac®. There were no statistical significant differences between the two drugs in al pharmacokinetic parameters including AUC_0-48hr of norfluoxetine.

골결손부 치유과정에서 cone beam형 전산화단층영상의 정확도

강호덕,김규태,최용석,황의환 대한구강악안면방사선학회 2007 Imaging Science in Dentistry Vol.37 No.2

Purpose : To evaluate the accuracy of the imaging reformation of cone beam computed tomography for the assessment of bone defect healing in rat model. Materials and Methods : Sprague-Dawley strain rats weighing about 350 gms were selected. Then critical size bone defects were done at parietal bone with implantation of collagen sponge. The rats were divided into seven groups of 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks. The healing of surgical defect was assessed by multiplanar reconstruction (MPR) images and three-dimensional (3-D) images of cone beam computed tomography, compared with soft X-ray radiograph and histopathologic examination. Results : MPR images and 3-D images showed similar reformation of the healing amount at 3 days, 1 week, 2 weeks, and 8 weeks, however, lower reformation at 3 weeks, 4 weeks, and 6 weeks. According to imaging-based methodologies, MPR image revealed similar reformation of the healing amount than 3-D images compare with soft X-ray image. Among the four threshold values for 3-D images, 400-500 HU revealed similar reformation of the healing amount. Histopathologic examination confirmed the newly formed trabeculation correspond with imagingbased methologies. Conclusion : MPR images revealed higher accuracy of the imaging reformation of cone beam computed tomography and cone beam computed tomography is a clinically useful diagnostic tool for the assessment of bone defect healing.

표고 버섯 중의 Branched chain amino acid Aminotransferase 의 분리정제 및 그 성질에 관한 연구

배강규,민태진,이수용 동국대학교 자연과학연구소 1987 자연과학연구 논문집 Vol.7 No.-

표고버섯중의 branched chain amino acid aminotransferase〔BCAT(EC 2,6,1,42)〕를(NH₄)₂SO₄ 분별침전, DEAE-cellulose column chromatography 및 sephades G-150겔 여과로 정제하여 그 특성을 조사하였다. 이 효소의 최적 pH는 8.5, 최적 온도는 36℃였고, 20℃이하에서 30분동안 열에 안정하였다. 이효소의 분자량은 69,000dalton이었으며, 산 가수분해하여 아미노산을 분석한 결과 18종의 서로 다른 아미노산들로 구성되어 있었다. 이 효소는 가지달린 아니노산인 L-valine, L-leucine 및 L-isoleucine에 대해서 특이성을 보였으며 phenylamine, potassium cyanide, phenylhydrazine, N-ethylmaleimide 및 p-chloromercuribenzoate에의하여 효소활성이 억제되었다. 또 한, L-leucine, a-ketoglutarate 및pyridoxal-5-phosphate에대한 이 효소의 Km값은 각 각 2.40mM, 2.98mM 및 1.74uM이었다. Branched cnain amino acid aminotransferaase 〔BCAT (EC 2.6.1.42)〕was purified by ammonium sulfate saturation. DEAE-cellulose column chromatography and sephadex G-150 gel filtration in Lentinus edodes(Berk.) Sing. Optimum pH and temperature were found to be 8.5 and 36℃, respectively. Apparent molecular weights of this enzyme was estimated 69.000 dalton by HPLC and SDS-PAGE. It showed activity toward L-leucine, L-isoleucine and L-valine as a substrate. It was ingibited by hydroxylamine, potassium cyanide, phenylgydrazine. N-ehylmaleimide, p-chloromercuribenzoate (CMB). cupric acetate and mercuric chloride. The Km values of this enzyme were determined to be 2.40mM for leucine, 2.98mM for a-ketoglutarate and 1.74μM for pyridexal-5- phospate, respectively.

ATM 교환망에서 ADSL 기반 가입자 선로의 성능분석

김중규,김용진,강각흠 大邱大學校 科學技術硏究所 1998 科學技術硏究 Vol.5 No.4

In this paper, ADSL function of ATM switching system has been examined and ADSL service test has been performed in real enviroment. The customer service loop range and its performance evaluation of 10^(-7) cell losses specification has also been tested in order to provide general customers with ADSL service using pair line that can be operated via already established voice telephone subscriber line on ATM. In addition, it can be thought that, with careful consideration, there is no trouble to apply ADSL technique nationally. The test results show that very high speed information telecommunication network of over 2Mbps can be worked with fair line condition of 3.7km, representative line noise condition of 3.4km, and 3.35km in the worst case(each cases the diameter of line is 0.4mm). Therefore ADSL technique with ATM can be applied to national subscriber line, and further more this technique will be appropriate service medium that can reduce the enormous investment and the construction term of national very high speed information telecommunication network.

기계학습기법을 통한 불임환자 데이터의 종속성 분석

정용규,강희규,박원일 凡石學術奬學財團 2002 凡石學術論文集 Vol.6 No.1

A large amount of data is obtained from patients seeking to achieve pregnancy through medical treatment. The data evolved from infertility treatment must be considered in many aspects about their characteristics and it is often difficult to find the cause of the problem due to many unexplained factors involved with infertility. The complexity of data makes it difficult for specialists to decide the correct therapy to approach. This paper presents our empirical research in Bayesian network. We constructed a Bayesian network and intestigated the utiity of the Bayesian network in identifying the relations between the factors affecting medically assisted conception. The Bayesian network classifier derived from the field data corresponds to confirms the domain knowledge that the age of female partner and the total number of embryo transferred play the key role in pregnancy. Applied to test cases for predicting target value of pregnancy, the Bayesian network shows the highest accuracy rate compared to heuristic and Naive-Bayes network classifiers.

위절제술 환자의 표준진료지침 개발 및 적용 효과

김은희,김철규,이순교,김순덕,이혜옥,권정순,이경미,이민미,심순미,유용만,신종식,강은희,이상일,김병식,오성태,육정환,박수길 한국의료QA학회 2003 한국의료질향상학회지 Vol.10 No.2

Background : Gastric cancer is the most common malignant tumor in Korea. surgical operation is one of the major treatment modalities for gastric cancer patients. Therefore, gastrectomy is one of the most common procedures in General Surgery. There were variation in length of hospital stay and medical treatment for gastrectomy between three surgeons at Asan Medical Center. Clinical pathways have received considerable attention as a tool for recucing the medical practice variation, increasing the efficiency of care process, and improving the quality of care. The aim of this study was to evaluate the effect of a clinical pathway for gastrectomy in gastric cancer patients. Methods : The clinical pathway for gastrectomy was developed and implemented by a multidisciplinary group in Asan Medical Center. A computerized clinical pathway program was developed and revised after a pilot test. A total of 145 patients underwent gastrectomy by three surgeons at Asan Medical Center. We compared the length of hospital stay, patient satisfaction, and unplanned readmission rate between the pre-pathway group(n=67) and the post-pathway group(n=78). We also investigated the degree of satisfaction among the physicians and nurses who were main end-users of the clinical pathway. Results : The clinical pathway was applied to all target patients. The average length of hospital stay was shortened from 12.7days to 10.6days(p<0.01). The degree of patient satisfaction with the care process changed from 90.3% to 89.2% after the implementation of the clinical pathway, but the difference was of satistically significant(p=0.761). Unplanned readmission rate was 2.9% in the pre-pathway group. More than 90% of physicians and nurses answered that the clinical pathway had been a useful tool in their medical practice. Conclusions : The findings of the study demonstrated that implementation of the clinical pathway for gastrectomy produced substantial reduction in the length of hospital stay while improving the quality of patient outcomes. The computerized clinical pathway program can be used as one of the powerful patient management tools for reducing the practice variations and increasing the efficiency of care process in Korea hospital settings.

비집속빔을 이용한 CO_2 레이저 빔 조사강화

서정,이제훈,강희신,김정오,이문용,오상진,이규현 한국레이저가공학회 2003 한국레이저가공학회지 Vol.6 No.2

Defocused CO_2 laser beam irradiation strengthening of 60kgf/㎟ grade steel sheet was investigated to obtain the tensile strength similar to that of fully penetrated one by the focused beam. The melted line width by the defocused beam was 3∼4 times larger compared to that of the focused beam. However, the increase of tensile strength with 1 line irradiation by the defocused beam was similar to that of 2∼3 lines by the focused beam. The increase(37.6%) of bending strength with 1 line by the defocused beam was higher than the increase(12.9%) of tensile strength. Also, the effect of cooling gas to strengthening was observed.