성견에서 표면처리된 교정용 마이크로임플랜트의 골 접촉률 및 동요도

박승현,김성훈,류준하,강윤구,정규림,국윤아 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.6

The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. Methods: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150 - 200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using Periotest. Results: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. Conclusions: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage. 본 연구는 비글견에 식립된 sandblasted, large grit and acid-etched (SLA) 표면처리된 교정용 마이크로임플랜트와 평활면 마이크로임플랜트에 교정력을 가한 후 시간 경과에 따른 동요도와 골접촉률의 차이를 규명하기 위해 시행되었다. 비글 성견 네 마리를 이용하여 상, 하악 협측과 구개측 골에 대해 SLA 표면처리된 표면처리군 48개, 평활면의 비처리군 48개의 마이크로임플랜트 96개를 식립하고 2주의 치유기간 후 교정력(150 - 200 g)을 지속적으로 가했으며 식립 4주 후에 두 마리를 희생시키고, 12주 후에 나머지 2마리를 희생시켰다. 표면처리군과 비처리군 간의 마이크로 임플랜트의 동요도와 골과 임플랜트 간 접촉률을 조직학적인 측면에서 측정 비교하여 다음과 같은 결과를 얻었다. 상악 협측과 구개측에서는 표면처리군과 비처리군의 동요도에서 유의성 있는 차이가 없었으나 하악협측에서는 표면처리군이 유의하게 안정적인 동요도를 보였다. 마이크로임플랜트와 인접골 간 접촉률은 상악 협측에서는 4주와 12주 모두 표면처리군과 비처리군 간에 유의한 차이가 없었으나 하악 협측과 구개측의 경우 4주와 12주 모두 표면처리군이 비처리군에 비해 유의하게 높은 접촉률을 보였다. 표면처리군은 비처리군에 비해 임플랜트 주변에서 활발한 골개조가 관찰되었으며 모든 군에서 이물반응은 관찰되지 않았다. 본 연구를 통해 SLA 표면처리된 마이크로임플랜트는 평활면 마이크로임플랜트에 비하여 식립 초기에는 식립 부위에 따라 유의하게 높은 인접골 간 접촉률과 동요도의 안정성을 보임으로써 다양한 크기와 방향의 교정력의 적용이 가능할 것이라 생각한다.

응급센터에서 기관내 삽관을 시행하지 않은 호흡곤란 환자의 동맥혈 이산화탄소분압과 호기말 이산화탄소분압의 연관성분석

김형국,박승현,오동렬,박규남,이원재,황두영,최승필,이운정,정시경,김세경 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Background: The end-tidal carbon dioxide tension(ETCO₂) is defined as a partial pressure of carbon dioxide at the end of an exhaled breath. The purpose of this study is to determine the correlation between ETCO₂and arterial carbon dioxide tension(PaO₂) in nonintubated patients with respiratory distress in emergency department(ED). Methods: A prospective non-blind study was performed in ED of our university hospitals. Participants included all nonintubated adult patients with respiratory distress requiring arterial blood gas analysis. ETCO₂was measured with a capnography monitor during tidal volume breathing. ETCO₂were recoreded at the time of arterial blood gas sampling. The correlation between ETCO₂and PaCO₂was analyzed in all patients and in subgroups by simple linear regression. Results: Sixty patients were enrolled. In all patients, ETCO₂was 5.72mmHg lower than PaCO₂and correlated well with PaCO₂(r²=0.716). ETCO₂correlated best with PaCO₂in patients who were either acidotic or non-smoking. Conclusion: ETCO₂correlate well with PaCO₂in nonintubated patients with respiratory distress in ED. ETCO₂may be sufficient to reflect PaCO₂in selected patients and obviate the need for repeat arterial blood gas determination.

저속 충격을 받는 적층판의 충격거동과 손상에 관한 연구

안국찬,김규수,박승범,황병선 한국산업안전학회 2002 한국안전학회지 Vol.17 No.1

This paper presents the impact behavior and damage of laminated composite plates subjected to the low-velocity impact. For this purpose, a pendulum impact test for impact behavior and C-scan for impact damage are done. Test materials are carbon/epoxy laminated composite plates and stacking sequences [0/90]_4, [0/45_2/-45]_s, [45_2/-45/90]_s, [0/45/-45/90]_s and [0/26/51/77/-77/-51/-26/0].

Interleukin-2가 Mouse 간실질세포의 미세구조에 미치는 영향

손승국,백태경,이규식,정호삼 한양대학교 의과대학 1990 한양의대 학술지 Vol.10 No.1

It is well known that interleukin-2, a kind of lymphokine produced by the lymphocytes stimulated by antigen or mitogen, mediates antitumor effects by stimulating the proliferation of helper and cytotoxic T-cells, augmenting the tumorlytic activities of natural killer cell and promoting the differentiation of precusor T-cell into lymphokine activated killer cell in vivo. Thus interleukin-2 has been widely used as immunotherapeutic agent for various sarcoma and carcinoma and also regressed the metastasis of malignant tumors. Although interleukin-2 is beneficial to cancer patient, it also develops many toxic effects such as fever, chillness, general malaise, mental confusion, vomiting, diarrhea, hepatic and renal dysfunction, and capillary leakage syndrome, including the general edema, heavy weight gain, ascites any pulmonary edema, which limits clinical use of interleukin-2. The author undertook this experiment to pursue the effect of interleukin-2 on the ultrastructure of hepatocyte in mice. A total of 75 healthy male DDY mice, weighing about 20gm, were used as experimental animals. The experimental animals were divided into the control and interleukin-2 treated groups, and then interleukin-2 treated mice were subdivided into 6 hours, 12 hours, 24 hours and 48 hours groups by intervals of time after administration and each group allocated 15 mice. Mice of interleukin-2 treated group were administrated with 2 million unit of interleukin-2, per kg of body weight, diluted in intraperitoneally. Animals were sacrificed 6,12,24 and 48 hours after administration. The specimens, left anterior hepatic lobe, were prefixed in 2% glutaraldehyde-2,\.5% paraformaldehyde solution buffered by Millonig's phosphate buffer (pH 7.2) for 2-4 hours and postfixed in 1% osmium tetroxide buffered by same buffer solution for 2 hours at 4℃. After dehydration, the specimens were embedded in Epon 812 and the ultrathin sections, 600-800A inthickness, were made with LKB V ultramicrotome. The preparations were stained with uranyl acetate and lead citrate and observed with JEM 100cx-II electron microscope. The result obtained were as follows; 1. Dilation, sacculation and disruption of cisternae of rough endoplasmic reticulum accompanied with dissociation of membrane bound ribosome were observed but as time goes by, these changes were recovered. 2. Disorganization of mitochondria was observed. 3. Proliferations of smooth endoplasmic reticulum associated with depletion of glycogen particles was recognized. But as time goes by, the glycogen particles were represented. 4. Numerous variously sized autophagic vacupoles and multivesicular bodies were observed. 5. Numerous lipid droplets were observed but they were disappeared as time goes by. Based on the result obtained, it is suggested that interleukin-2 would induce changes of ultrastructures of hepatocyte in mouse but these changes were recovered as time goes by.

유리 성형용 금형의 균열 발생 기구

황규홍,송동환,양권승,이종국 조선대학교 생산기술연구소 2005 生産技術硏究 Vol.27 No.2

Microstructure of glass-forming mold have influence on the mechanical properties such as hardness, and life span of the glass-forming mold is strongly dependent on its microstructure. The glass-forming mold with guaranteed tool life requires fine particle size and homogeneous distribution of Cr precipitates in the matrix. In this study, mechanism on the crack creation of the glass-forming mold made in Korea (K-mold) was compared to the one glass-forming mold made in Japan (J-mold). SEM observation revealed that the particle size of the Cr precipitates in J-mold was smaller than that in K-mold, in addition the size distribution of J-mold was narrower than that of K-mold, resulting in long life of J-mold. Therefore, it was confirmed that the microstructure of the glass-forming mold related to Cr precipitates was one of the important parameters to improve the quality of products.

상부위장관 출혈의 임상적 고찰

장금석,이승일,박삼규,조건국,장정수 조선의대 1984 The Medical Journal of Chosun University Vol.9 No.1

데페록사민 전처치가 토끼 심근경색 크기의 감소에 미치는 효과

양관모,오동렬,박승현,박규남,이원재,김형국,황두영,최승필,채장성 대한응급의학회 1998 대한응급의학회지 Vol.9 No.4

Background: Reperfusion of ischemic myocardium has been postulated to result in a specific oxygen radical mediated tissue injury. Iron may liberate during ischemia and we hypothesized that administration of the iron chelator, deferoxamine during ischemia would result in improved recovery after postischemic reperfusion. Purpose: To test whether iron-catalyzed processes contribute to myocardial necrosis during ischemia and reperfusion, deferoxamine was administered to block iron catalyzed hydroxyl radical formation in rabbits. Methods: Eleven rabbits were divided into two groups : control group (n=5) and deferoxamine pretreatment group (n=6). The left circumflex coronay artery was ligated for 30 minutes and reperfused for 180 minutes. Area at risk (AR) was measured by non-stained area with methylene blue injection into left atrium after left circumflex coronary artery ligation. Infarct size was measured by weighing after triphenyltetrazolium chloride staining. Heart rate was measured using electrocardiographic recording and systemic blood pressure was monitored by pressure transducer connected to the catheter in the left ventricle. Results: 1. There was no significant difference of heart rate and blood pressure in deferoxamine pretreatment group compared with control group. 2. There was significant decrease of serum iron concentration after continuous infusion of deferoxamine compared with serum iron concentration before ligation of coronary artery(P<0.05). 3. There was no significant difference of area at risk between control and deferoxamine pretreatment group. 4. Area at necrosis to area at risk was significantly reduced in deferoxamine pretreatment group compared with control group(P<0.05). The results suggest that deferoxamine infusion prior to coronary artery occlusion has a significant benefit in reducing infarct size in this model.

분석결과 검증 및 신뢰성 확보를 위한 실험실간 협력 실험

박혜진,고광용,한국탁,김일중,이용재,김성헌,이규승 충남대학교 농업과학연구소 2005 농업과학연구 Vol.32 No.2

The residual study of pesticide has been used in various areas, such as food safety, environmental protection, establishment of tolerance, and explaining the pathway and reaction mode of pesticides, and its importance was expected to increase further more. The aspect of food safety, the pesticide residue survey have been practiced at many organizations, but there were no verification of analytical results at present. In this experiment, we focused on instrumental stability, including response of each instrument and the recovery ratio of each organization's method. As samples for this experiment, we prepared cucumber and sesame, and chose 4 pesticides (bifenthrin, chlorpyrifos, diazinon, and ethoprophos), which were mostly detected from pesticide residue survey and widely used for each crop. The standard deviation of peak areas in the chromatogram of each pesticide were under 1.212 %, so it showed that most instruments were stable. The relationship of recovery ratio of each organization were over 0.996 for every pesticide and each organization. Finally, the analytical results for pesticide residue from each participated organization were not statically significant and we could put confidence in the result from each organization.

응급의료센터에서 신경색의 조기진단

최경호,오동렬,이원재,박규남,박승현,황두영,김형국,정시경,김영민,김세경 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

To evaluate appropriate diagnostic studies for renal infartion in emergency medical center, we analysed 33 patients of renal infarction treated in this hospital for last 8 years. Eleven patients, 4 trauma associated and 7 aortic disease associated patients were excluded. They are 11 males and 11 females with a mean age of 51 years. Fourteen came to the emergency medical center and seven came to the outpatient department, in the other one patient renal infarction was developed during hospitalization with other disease. On their past history they had hypertension in 9, valvular heart disease in 5, and diabetic mellitus in 4 patients. Abdominal or flank pain was noted in 17 of 22(77%). The other symptoms were vomiting, nausea, fever and so on. On microscopic examination of initial urine in hospital, 5 patients showed more than 10 red blood cells by high power field examination. The mean lactic dehydrogenase level was 1,239 I.U/L(normal range 218-472 I.U/L), while the mean aspartate aminotransferase and mean alanine aminotransferase were 51 I.U/L(normal range 13-36 I.U/L) and 44 I.U/L(normal range 5-33 I.U/L). Abdominal ultrasonography showed positive findings in 5 of 16(31%), of which 3 were confirmed by Doppler ultrasonography. In 18, computed tomography was done and all those showed positive findings of renal infarction(100%). In conclusion, it is important that identify the elevated lactic dehdrogenase level in case of any suspicion about renal infarction and confirm by computed tomography.

65세 이상의 노령층에서 고지혈증의 위험요인

김용배,장원기,황보영,김화성,안규동,이병국,이용진,김세훈,김승수,김승훈,김영록,김웅빈,이성수 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.1

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