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      • SCOPUSKCI등재

        COPA(cuffed oropharyngeal airway)를 이용한 마취 유도 시 근이완제 사용 유무에 따른 반응

        김상태,배진호,김상범,임승운,민병상,신영덕 대한마취과학회 2000 Korean Journal of Anesthesiology Vol.38 No.3

        Background : COPA (cuffed oropharyngeal airway) is a convenient device for airway management in patients undergoing general anesthesia for elective surgery in supine position. It causes less pharyngeal trauma than LMA(Laryngeal mask airway). The purpose of this study was to compare the effect of COPA with and without muscle relaxant. Methods : Forty patients with ASA physical status I and II for elective surgery were randomly assigned to two groups. Anaesthesia was induced with propofol (2 mg/kg) and vecuronium (1.5 mg/kg) and was administered intravenously in Group I but not in Group II. Mask ventilation was done for 5 min with 0: 5 L/min. COPA was placed and heart rate, and systolic, mean, diastolic blood pressure and peak inspiratory pressure were measured at 1 min interval for 5 min. Anaesthesia was maintained with pro- pofol 150 ㎍/kg/min, fentanyl 1 ㎍/kg/hr, O_2 2 L/min and N_2O 2 L/min. Results : There were no significant differences between Group I and Group II in heart rate, systolic, mean and dstolic blood pressure. PIP (Peak inspiratory pressure) was increased and hiccups occurred significantly (p $lt; 0.05) in Group II. Complete airway obstruction occurred in one patient of Group I and severe coughing, body movements and gagging occurred during induction and insertion in Group II. conclusions : With the use of appropriate muscle relaxant, we can use COPA without increased inspiratory pressure or significant complication. (Korean J Anesthesiol 2000; 38: 399~403)

      • KCI등재
      • KCI등재

        Streptococcus salivarius의 요소분해효소 활성에 관한 연구

        정상백,최호영,민병순,박상진,이진용,최기운 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1

        Dental caries is induced by organic acids produced by oral bacteria. In order to prevent dental caries, therefore, it is essential to maintain neutral pH in the oral cavity. Urea plays a major role in oral pH homeostasis. Urea is hydrolyzed by bacterial ureases to ammonia, causing a pH elevation, Streptococcus salivarius has been shown to be a major contribution to oral ureolysis. Synthesis of urease by S. salivarius appears to be constituitive, but can be greatly enhanced by low pH. It is, therefore, conceivable that ureolytic activity of S. salivarius from a carious lesion is greater than that of the bacterium from a healthy tooth. In the present study, urease activity of S. salivarius isolates from dental plaque of carious lesions was compared with that of the isolates from plaques of the teeth and the dorsum of the tongue; 45 S. salivarius strains were isolated from carious lesions(>C2) of 21 individuals with dental caries and 30 strains from 10 individuals without dental caries. The results were as follows: 1. All the 21 individuals with dental caries harbored ureolytic S. salivarius whereas 3 of 13 individuals without dental caries harbored non-ureolytic strains of S. salivarius. 2. All the 45 S. salivarius isolates from carious lesions showed urease activity. In contrast, of 30 isolates from individuals without dental caries, 17 isolates(56.7%) did not demonstrate urease activity, or if any, very little(<5μmol/min/mg). 3. Urease activity of the isolates from carious lesions was greater than that of the isolates from individuals without dental caries:the urease activity ranged from 42 to 381μmol/min/mg and from 0 to 208μmol/min/mg, respectively. 4. At acid pH(5.5), the isolates which showed intermediate urease activity at pH 7.0 demonstrated even higher activity whereas the isolate with no or lower urease activity did not show any significant difference in their activity. However, the isolates with the greatest urease activity from both individuals with and without dental caries, exhibited a rather much lower urease activity at pH 5.5. The overall results suggest that isolates may have their own urease activity but the isolates exposed to chronic acidic environment of the carious lesion might elevate urease activity of S. salivarius, which in turn, might influence on survival of S. salivarius itself and other bacteria establishing a new oral bacterial ecosystem.

      • SCISCIESCOPUS

        Microfluidic generation of Prussian blue-laden magnetic micro-adsorbents for cesium removal

        Kang, Sung-Min,Rethinasabapathy, Muruganantham,Hwang, Seung Kuy,Lee, Go-Woon,Jang, Sung-Chan,Kwak, Cheol Hwan,Choe, Sang-Rak,Huh, Yun Suk Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.341 No.-

        <P><B>Abstract</B></P> <P>Here, we designed and synthesized a recoverable multifunctional adsorbent using a microfluidic reaction system and evaluated the removal performance of the smart adsorbent toward radioactive cesium as a model sample. Prussian blue-laden magnetic micro-adsorbents (PB-MNPs-MAs) with uniform morphology and monodispersity were generated via two-step sequential procedures using a glass capillary microfluidic system, followed by chemical co-precipitation with a high production rate. The cesium removal efficacy of the PB-MNPs-MAs was analyzed based on Langmuir and Freundlich isotherms by controlling adsorption parameters such as adsorbent size, initial cesium concentration, and contact time. The adsorption isotherm of the PB-MNPs-MAs was better fitted to the Langmuir model with a maximum cesium adsorption capacity of 58.73 mg g<SUP>−1</SUP>, which was 40% higher than that of macro-adsorbents in a dynamic magnetic field. This result can be attributed to their large specific area, which increased the kinetic rate of cesium adsorption and achieved saturation within 20 min. Additionally, the PB-MNPs-MAs were recovered from wastewater within 5 s under a static magnetic field, indicating their great potential for magnetic actuation. We believe that our PB-MNPs-MAs can encapsulate nano-functional adsorbents and prevent actuation, making them promising for environmental remediation and especially for removal of radionuclides.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PB-MNPs-MAs were generated in microfluidic device using chemical co-precipitation. </LI> <LI> The prepared PB-MNPs-MAs are monodispersed with uniform morphology. </LI> <LI> PB-MNPs-MAs exhibited high Cs adsorption capacity (58.73 mg g<SUP>−1</SUP>). </LI> <LI> 100% recovery of PB-MNPs-MAs is possible under static magnetic field after Cs adsorption. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

      • SCOPUSKCI등재

        C -11 및 F - 18 표지 콜린의 합성과 체내동태에 관한 연구

        전권수,유국현,김상욱,임상무,홍성운,서용섭,양승대,안순혁,허민구 대한핵의학회 2001 핵의학 분자영상 Vol.35 No.3

        Objectives: Recently, [methyl-(11)^C]-(β-Hydroxyethyl)trimethylammonium ([(11)^C]choline) has been discovered to be a very effective tracer in imaging various human tumors using positron emission tomography. Because of the short half-life of C-11, it is very difficult to use in a routine imaging procedure and needs a frequent synthesis of [(11)^]choline. This can be supplemented by the substitution of [(11)^Ccholine with [methyS-18]fluorocholine. Here, we would like to report cell uptake and biodistribution of [(11)^Ccholine and [(18)^F]fluorocholine as a basic study. Methods [(11)^C]Choline was prepared by the treatment of [(11)^C]CHzI with N,N-dimethylaminoethanol and [18F]fluorocholine was synthesized from reaction of CHzBr[18F]F with N,N-dimethylaminoethanol. The radiochemical purity was checked by high performance liquid chromatography (HPLC). The biodistribution of [(11)^C]choline and [(18)^F]fluorocholine was determined in balb/c mouse at 5 min, 20 min, 40 min and 80 min. The cell uptake wa measured using glioma (9L) and colon adeocarcinoma (SW620). Results: The radiochemical purity was more than 98% after purification. In the liver, uptake did not change over time the uptake was 20/ID/g for [C]choline and 13%ID/g for [(18)^F]fluorocholine. In the kidney, radioactivity decreased over tirne the uptake was 15%1D/g for [(11)^Ccholine and 20%ID/g for [(18)^F]fluorocholine, 80 min post-injection. The cell uptake of [(11)^Ccholine was 4.93% for glioma (9L) and 18.69F for colon adenocarcinoma (SW620). For [(18)^F]fluorocholine, 1.77% for glioma (9L) and 2.77% for colon adenocarcinoma (SW620). Conclusion: [(11)^CCholine and [(18)^F]fluorocholine showed a different cell uptake tendency, depending on cancer cell line. (Korean J Nucl Med 200135:185-191)

      • KCI등재
      • KCI등재

        Cao-MgO-SiO₂-P₂O -CaF₂계 생체활성 결정화 유리의 기계적 성질에 미치는 ZrO₂및 Al₂O₃의 분산 강화 효과

        박찬운,강건구,원대희,이민호,배태성 대한치과기재학회 1998 대한치과재료학회지 Vol.25 No.2

        Bioactive glass-ceramics can form tight chemical bonds with bone, however, their poor mechanical properties may limit their clinical applications. Alumina ceramics show good biocompatibility and high strength but can't form chemical bonds with bone. Hydroxyapatite ceramics and bioglass form chemical bonds with bone but their strength and fracture are relatively low. Glass ceramics containing apatite and wollastonite crystals can form tight chemical bonds with bone and show relatively high strength and fracture toughness. Bioactive glass-ceramics toughened by alumina and tetragonal zirconia polycrystals show relatively high mechanical strength. Both bioactive and high strength ceramics will be widely applicable to many clinical applications. In this study, bioactive glass-ceramics toughened by alumina and zirconia polycrystals were fabricated, and crystallization behavior, biaxial flexure strength, fracture toughness, and bioactivity were measured. The results obtained were summarized as follows; 1. The major crystaline phase in the matrix glass were observed to be apatite, wollastonite, and β-TCP. 2. Biaxial flexure strength and fracture toughness values were more improved by the dispersion toughening of alumina and zirconia, and the improvement of mechanical strength was more higher in the dispersion toughening of zirconia than that of alumina. 3. The bioactivity, which was evaluted from apatite formation in the simulated body fluid, was higher in the dispersion toughening of Zr-O₂than that of Al₂O₃.

      • KCI등재

        상아질 접착제 사용 여부에 따른 근관 밀폐효과의 비교

        이민조,박상혁,최기운 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.1

        이 연구의 목적은 상아질 접착제의 사용 여부에 따른 근관 밀폐효과를 비교 평가하기 위해 40개의 단근치를 근관 성형 후 20개씩 두군으로 나누었다. 1군은 근관 충전시에 상아질 접착제를 사용하지 않았으며 2군은 상아질 접착제를 사용하였다. 근첨에서 1.5 mm (Level 1), 2.0 mm (Level 2), 2.5 mm (Level 3) 떨어진 부위의 평균 누출률을 측정하였다. 1. 두군의 평균 누출률은 치경부로 향하면서 감소하였다. 2. Level 1에서 1군과 2군의 평균 누출률은 차이가 없었다 (p > 0.05) .3. Level 2와 3에서 2군의 평균 누출률은 1군보다 낮았으며, 통계학적으로 유의차를 나타내었다 (p < 0.05) .연구결과 상아질 접착제를 사용하여 근관 충전하는 경우 치근단 누출을 감소시킬 수 있을 것으로 판단된다. The purpose of this study was to compare the sealing ability of root canal obturation with or without the use of dentin adhesive system. Forty extracted human teeth with one canal were selected and decoronated. The teeth were divided into two Groups. The obturation procedure of Group 1 was the same as that of Group 2 with the exception of dentin adhesive system. Group 2 were obturated with dentin adhesive system, AH-26, and gutta-percha. After obturation, the teeth were immersed in methylene blue solution for 84 hours. The teeth were sectioned horizontally at 1.5 mm (Level 1), 2.0 mm (Level 2) 2.5 mm (Level 3) from the root apex using a low speed microtome. Distance of dye-penetrated surface and total dentinal surface were measured using SigmaScan Pro 5.0, and the ratio of dye-penetrated distance to the total dentinal distance was analyzed statistically by Mann-Whitney U-test. 1. In both groups, the mean leakage ratio was decreased cervically. 2. At level 1, there was no significant difference between group 1 and group 2 (p > 0.05). 3. At level 2 and 3, group 1 showed significantly higher mean leakage ratio than group 2 (p < 0.05). The results suggest that using dentin adhesive system in root canal obturation procedure reduces the apical microleakage.

      • 문자영상 紬線化에서의 雜音除去 알고리즘에 관한 연구

        전병민,박규태,김상운,이기돈 연세대학교 산업기술연구소 1984 논문집 Vol.16 No.2

        In this paper, we study thinning algorithms which are peeling off successive contours of the character image to be thinned while keeping the connectivity of the skeleton in the process. Noise rejection algorithm is proposed for the purpose of removing the common short-comings of thinning algorithms when applied to hand-printed data. The algorithm consists of the three processings: preprocessing, thinning, and postprocessing. The preprocessing smooths down the originally-thick image and the postprocessing leads to the well-groomed skeleton. The noise rejection algorithm is implemented with FORTRAN language and tested through a CYBER170-825 computer system.

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