고령자 급성 췌장염의 임상적 고찰

백용한,서정훈,송건훈,이진헌,송시영,정재복,강진경,박인서,이수진 大韓消化器病學會 1998 大韓消化器病學會誌 Vol.32 No.3

New method for an evaluation of the esthetical improvements resulting from a mandibular angle reduction

Joo-Hwan Kim,Se-Jin Han,Moon-Young Kim 대한구강악안면외과학회 2017 대한구강악안면외과학회지 Vol.43 No.4

Objectives: This paper proposes Han’s ratio as an objective and quantitative comparative result obtained from pre and postoperative data in patients with a mandibular angle reduction. Materials and Methods: Thirty patients, 12 men and 18 women, who visited the Department of Oral and Maxillofacial Surgery with the chief com-plaints of skeletal mandibular prognathism and prominent mandibular angle were selected. The subjects were classified into 3 groups according to the types of surgical procedures involved. Group A consisted of patients who underwent mandibular angle resection and mandibular setback. Group B was comprised of patients with mandibular angle resection, mandibular setback and genioplasty. Group C consisted of patients with mandibular angle resection, mandibular setback, Le Fort I osteotomy, and genioplasty. The landmarks placed in pre and postoperative frontal photographs were used to obtain the Han’s ratio in each group. The Han’s ratios were compared pre- and postoperation and according to the surgical techniques applied. Results: Of the 3 groups who had undergone a mandibular angle resection, all showed a statistically significant increase in Han’s ratio. On the other hand, there was no statistically significant difference based on the surgical techniques used. Conclusion: The ratio of the lateral lower face proposed in this study is a potential indicator of postoperative esthetic enhancement in mandibular angle reduction surgery.

Crystal Structure of a Methanol Sorption Complex of Dehydrated Partially Cobalt(Ⅱ)-Exchanged Zeoite A

韓榮旭,張世福,金洋 부산교육대학교 과학교육연구소 1993 科學敎育硏究 Vol.18 No.-

부분적으로 Co^2+ 이온으로 치환한 제올라이트 A를 탈수한 후 메탄올을 흡착한 결정구조(a=12.169(1) A)를 입방공간군 Pm3m를 사용하여 단결정 X-선 회절법으로 해석하고 정립화하였다. 이 결정은 360˚C에서 2±10^+Torr 하에서 2일간 진공 탈수한 후 22(1)˚C에서 약 104Torr의 메탄올 증기로 약 1시간동안 흡착시켰다. Full-matrix 최소자승법 정밀화 계산에서 1>3α(1)인 147개의 독립 반사를 사용하여 최종 오차 인자를 R1=0.061, R2=0.062까지 정밀화시켰다. 단위세포당 4개의 Co^2+ 이온과 1.5개의 Na^+ 이온은 6-링 산소와 결합하고 있었다. 4개의 Co^2+ 이온은 0(3)의 (111) 평면에서 큰 동공 쪽으로 약 0.44 (18)A 들어가 위치하고 1.5개의 Na^+ 이온은 0(3) (111)평면에서 소다라이트 동공 깊숙히 약 0.55A 들어간 자리에 이치하고 있다. 단위세포당 약 6.5개의 메탄올 분자가 흡착되었다. 단위세포당 약 6.5개의 메탄올 분자는 큰 동공 내에 위치하였고 4개의 Co^2+ 이온과 2.5개의 Na^+ 이온과 결합하고 있다.. 4개의 산소는 6-링에 위치한 Co^2+ 이온과 결합하고 나머지 2개의 산소는 6-링에 위치한 Na^+ 이온과 결합하고 있다. The crystal structure of a methanol sorption complex of dehydrated partially Co(Ⅱ)-exchanged zeolite A, Co_4Na_4-A 6.5CH_3OH(a=12.169(1) A˚), has been determined by singlecrustal x-ray diffraction techniques in the cubic space group Pm3m at 21(1)℃. Co_4Na_4-A was dehydrated at 360℃ and 2×10^-6 Torr for 2 days, followed by exposure to about 105 Torr of methanol vapor at 22(1)℃ for 1 hr. The structure was refined to fina error indices, R_1=0.061 and R_3=0.060 with 147 reflections, for which Ⅰ > 3σ(Ⅰ). In this structure, four Co^2+ ions and 1.5 Na^+ ions per unit cell lie at 6-ring positions:the Na^+ ions are recessed 0.444(18)A˚ into the sodalite unit and the Co(Ⅱ) ions extend ca. 0.55A˚ into the large cavity. 2.5 Na^+ ions lie in an 8-oxygen ring plane. The 6.5 methanol molecules are sorbed per unit cell. The 6.5 methanol oxygens, all in the large cavity, associate with the 4 Co^2+ ions and 2.5 Na^+ ions in two ways:four oxygens coodinate to 6-ring Co^2+ ions, and two coordinate to 8-ring.

산업부산물인 Fly Ash의 라이닝콘크리트에의 적용에 관한 실험적 연구

최세진,임정열,정우성,김완영,김무한 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

This is an experimental study to analyze the usability of fly ash in the tunnel lining concrete. For this purpose, the mix proportion of plain concrete and concrete using fly ash(the replacement of 15 and 30% by weight of cement) to satisfy slump 15cm, air content 5% and compressive strength 270kgf/cm2, was selected. And then tests for slump, setting time, compressive strength, tensile strength, drying shrinkage and adiabatic temperature rise were performed. According to test results, it was found that the concrete using fly ash 15% (FA 15 concrete) was better than the plain concrete and FA 30 concrete. FA 15 concrete was more useful than the others in reducing the drying shrinkage : the drying shrinkage strains of FA 15 concrete after 20 weeks of air drying was lower about 10% than the plain concrete, and lower 6% than FA 30 concrete. And the highest compressive strength after curing for 28 days of 365kgf/cm2 was obtained from FA 15 concrete. This was almost 10-20% improvement in compressive sterngth, compare to the plain concrete and FA 30 concrete. And the effect of 5~7.5℃ of concrete using fly ash for hydration heat reducing was calculated. Therefore, concrete using fly ash 15% (FA 15) was expected to improve the performance of lining concrete.

아저해농도(亞沮害濃度)의 항균물질이 mutans streptococci의 세포표면성질과 독력인자에 미치는 영향

김영재,한세현,이상훈,장기택,김종철 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.4

아저해농도(亞沮害濃度)란 세포의 성장을 저해하는 최소 저해 농도(minimum inhibitory concentration; MIC)이하의 농도를 말하는데, 적용된 화학물질의 동력학에 따라 항균물질은 반드시 이러한 농도로 존재하는 시기를 거치게 되며, 아저해농도의 항균물질은 세포의 성장을 저해하지는 않지만 세균의 대사와 성장에 스트레스로 작용하게 되어 세포의 성질과 독력인자 발현에 영향을 줄 수 있을 것이다. 본 연구는 여러 항균물질의 최소저해농도를 결정하고 아저해농도의 항균물질이 존재 시 세포 성질과 독력 인자에 미치는 영향을 알아보고, 치아우식증의 예방에 대한 화학적 접근법의 효용성을 조사하기 위해 계획되었다. 연구대상 세균으로는 mutans그룹 streptococci 중 두 가지 대표적인 세균종인 S. mutans (S. mutans Ingbritt)와 S. sobrinus (S. sobrinus 6715-7) 를 사용하였고 화학물질 8종 (Sanguinaria extract; SG, Chlorhexidine digluconate; CHX, Fluoride; F, Propolis; PP, Hydrogen peroxide; HP, Triclosan; TC, Sodium dodecyl sulfate; SDS, Cetylpyridinium chloride; CC) 을 단계 희석하여 배지에 첨가하여 최소저해농도를 구하였으며 아저해농도의 항균물질을 배지에 첨가하여 5% CO₂존재 하에 37℃에서 배양하여 이러한 항균물질을 첨가하지 않은 배지에서 배양한 세균과 성장속도, 산생성능, 체표소수성, 수산화인회석에의 부착능, glucan생성능, 세균응집능 등을 비교 관찰하였다. 아저해농도의 항균물질은 세포의 성장과 체표소수성, 타액 처리한 수산화인회석에 대한 세균의 부착과 glucan합성에 영향을 주는 것이 관찰되었다. 또한 12시간 배양 후 S. mutans와 S. sobrinus 모두에서 대조군에 비해 통계적으로 유의하게 최종 pH가 높게 나타나 산생성능이 억제되는 것이 관찰되었다 (p<0.05). 세균을 proteinase K로 전처리한 경우 처리하지 않았을 때 보다 세균응집역가가 증가하거나 응집이 관찰되지 않았다. 본 연구의 결과에 따르면 각각의 항균물질은 아저해농도에서도 알려진 작용기전과 유사하게 세균의 성질에 영향을 주었고 이러한 농도에서도 지속적으로 세균을 억제할 수 있었다. 따라서 이러한 항균물질의 사용은 치아우식증의 효과적 예방법의 하나가 될 수 있다. Subinhibitory concentrations (sub-MICs) refer to concentrations below minimum inhibitory concentrations (MICs). The antimicrobial agents may be present at relatively high concentration, at least higher than bacterial MIC and thereafter be desorbed off a surface and function at sub-MICs, perhaps by interfering with bacterial metabolism. Consequently, the aim of this study was to determine the effects of growth, in the presence of sub-MICs of antimicrobial agents, on the cell surface properties and virulence factors of mutans streptococci and to investigate the efficacy of a chemical approach in vitro. Streptococcus mutans Ingbritt and Streptococcus sobrinus 6715-7 were used. Eight antimicrobial agents (Sanguinaria extract;SG, Chlorhexidine digluconate;CHX, Fluoride; F, Propolis;PP, Hydrogen peroxide;HP, Triclosan;TC, Sodium dodecyl sulfate;SDS, Cetylpyridinium chloride; CC) were diluted serially in broth to determine MICs and to compare the growth rate, acid production, hydrophobicity, adhesion activity to saliva coated hydroxyapatite, glucan synthesis and cellular aggregation of experiment groups (in the presence of sub-MICs) with those of control (in the absence of antimicrobial agents). Sub-MICs of antimicrobial agents affected the growth of cells, hydrophobicity, and adhesion of bacteria to saliva coated hydroxyapatite and glucan synthesis. They also resulted in a significant reduction in pH after 12 hours (p<0.05). By cells pretreated with proteinase K. either the aggregation induced by antimicrobial agents was completely inhibited or the aggregation titers were markedly increased. According to the results of the present study, each antimicrobial agent at sub-MICs could affect similar as its known action mechanism and could continually inhibit cariogenic bacteria a t such concentrations. Thus, the use of these antimicrobial agents would be one of the effective methods to prevent dental caries.

마이크로그로브 형태에 따른 평활근 세포 운동 측정

유소영,박찬영,정석,김동익,이병붕,허세호,한동철,장준근 대한혈관외과학회 2002 Vascular Specialist International Vol.18 No.2

Purpose: The spreading, orientation, and chemotaxis the gradient of a chemoattractant of smooth muscle cells (SMCs) were studied on the micro-grooved substrata by the light, fluorescence and scanning electron microscopy. Method: Vertical-walled grooves were produced in silicon wafers by the micromachining technique. All grooves were 4~20㎛ deep and 10~80㎛ wide, SMCs were cultured on each microgroove and examined under stereo-microscope. Result: Cell clusters were markedly oriented by all the grooved substrata examined. Tim-lapse images acquired from CCD (Charge Coupled Device) showed that the grooves directed the migration of SMCs. There was no prominent difference in the migration speed of SMCs according to the grooves. All the cytoskeletal fibers were reoragnized in the same direction with grooves. Especially the alignments of microtubule and intermediate filaments were distinguished in the SMCs on the micro grooves. Conclusion: These results could be applied to the analysis of vascular restenosis and the development of artificial blood vessels.

A LONG-TERM FIELD TEST OF A LARGE VOLUME IONIZATION CHAMBER BASED AREA RADIATION MONITORING SYSTEM DEVELOPED AT KAERI

Kim, Han-Soo,Ha, Jang-Ho,Park, Se-Hwan,Kim, Jung-Bok,Kim, Young-Kyun,Jin, Hyung-Ho The Korean Association for Radiation Protection 2009 방사선방어학회지 Vol.34 No.2

An Area Radiation Monitoring System (ARMS) ionization chamber, which had an 11.8 L active volume, was fabricated and performance-tested at KAERI. Low leakage currents, linearities at low and high dose rates were achieved from performance tests. The correlation coefficients between the ionization currents and the dose rates are 1 at high dose rate and 0.99 at low dose rate. In this study, an integration-type ARMS ionization chamber was tested over a year for an evaluation of its long-term stability at a radioisotope (RI) repository of the Young-gwang nuclear power plant. The standard deviation of dose rate of 1 day data and over a 100-days mean value were 6.2 $\mu$R/h and 2.9 $\mu$R/h, respectively. The fabricated ARMS ionization chamber showed stable performance from the results of the long-term tests. Design and performance characteristics of the fabricated ionization chamber for the ARMS from performance-tests are also addressed.

지속적인 직류 자장이 백서의 임의형 피판생존에 미치는 영향에 關한 硏究

백세민,유영준,한흥수,오갑성 大韓成形外科學會 1994 Archives of Plastic Surgery Vol.21 No.3

The present study was undertaken to determine if direct current(DC) electirical fields could improve survival rate of random pattern skin flap in the rat. 20 Sparque- Dawley rats were divided into two groups and caudally based 2cm width and 8cm length random pattern flaps were elevated in all rats. Electrical fields of 9mA were introduced by 1.5V disk button battery. Electrical field was applied for 5days to the stimulation group(B). DC electrical fields shows the enhancement of flap survival by increasing the rate to 33.5%(p<0.01). The enhancement of skin flap survival by application of direct current electrical field has possibility for cover the large skin defect.

활성화 C 단백 내성검사의 정도관리와 한국인의 양성률

이영경,박성섭,이유경,이진숙,함천경,주세익,윤근영,박선양,조한익 대한임상병리학회 1996 대한임상병리학회지 Vol.16 No.6

생체 활성 A-W glass-ceramics에 대한 ZrO₂첨가효과

최세영,김정한 연세대학교 산업기술연구소 1992 논문집 Vol.24 No.1

The effect of the various ZrO₂contents on the mechanical properties and the behavior of densification and crystallization were investigated in the Bio-active Apatite-Wollastonite glass-ceramics in the system of MgO-CaO-P₂O5-SiO₂-CaF₂. The precipitated crystals in thermally treated A-W glass-ceramics were oxy/fluoraptite ?? and β-wollastonite[β-CaO·SiO₂]. Increasing the ZrO₂ contents up to 7Wt%, the mechanical properties were increased, but the bioactivity was decreased. For investigating the bio-activity, A-W glass-ceramics were soaked in the simulated body fluid (SBF solution) for 7 days at 36.5℃, and resulted in the formation of apatite layer of about 5㎛.