미세 물 흐름 측정장치의 개발과 상아세관액의 수력학에의 응용

이인복,김민호,김선영,장주혜,조병훈,손호현,백승호 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.2

본 연구의 목적은 나노리터 수준의 물 흐름을 계측할 수 있는 장치를 개발하고, 상아질의 물 투과성을 측정하여 치아과민증 치료제와 상아질 접착제의 상아세관 밀폐효과를 알아보고자 하였다. 본 연구에서 제작한 미세흐름 측정장치는 첫째, 물의 흐름을 감지하는 모세관과 광 센서부, 둘째 물의 흐름을 추적하는 서보모터와 구동부, 셋째, 모터의 회전을 측정하여 물의 이동량으로 변화하는 엔코더와 컴퓨터 기록장치 등 세 부분으로 구성되어 잇다. 본 장비를 이용하여 교합면이 절단되어 노출된 상아질의 물 투과도와 치아과민증 치료제인 BisBlock과 자가부식형 상아질접착제인 Clearfil SE bond의 상아질 밀폐효과를 측정하여 다음과 같은 결과를 얻었다. 1. 나노리터 수준의 물 흐름을 측정할 수 있는 장치를 제작하였고, 이를 이용하여 상아질의 물 투과도를 측정할 수 있었다. 2. 삭제 후 노출 연마된 상아질은 0.84 - 15.2 nL/s의 물 투과도를 보였고 Oxalate 제재인 BisBlock 이나 자가부식형 접착제 Clearfil SE bond 적용시 투과도가 39.8 - 89.6% 감소하였다. This study was aimed to develop an instrument for real-time measurement of fluid conductance and to investigate the hydrodynamics of dentinal fluid. The instrument consisted of three parts: (1) a glass capillary and a photo sensor for detection of fluid movement, (2) a servo-motor, a lead screwand a ball nut for tracking of fluid movement, (3) a rotary encoder and software for data processing. To observe the blocking effect of dentinal fluid movement, oxalate gel and self-etch adhesive agent were used. BisBlock (Bisco) and Clearfil SE Bond (Kuraray) were applied to the occlusal dentin surface of extracted human teeth. Using this new device, the fluid movement was measured and compared between before and after each agent was applied. The instrument was able to measure dentinal fluid movement with a high resolution (0.196 nL) and the flow occurred with a rate of 0.84 to 15.2 nL/s before treatment. After BisBlock or Clearfil SE Bond was used, the fluid movement was decreased by 39.8 to 89.6%.

단량체 및 무기질 filler 조성 변화에 따른 복합레진의 유변학적 특성

이인복,이종혁,조병훈,손호현,이상탁,엄정문 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.6

Objectives. The aim of this study was to investigate the effect of monomer and filler compositions on the rheological properties related to the handling characteristics of resin composites. Methods. Resin matrices that Bis-GMA as base monomer was blended with TEGDMA as diluent at various ratio were mixed with the Barium glass (0.7 um and 1.0 um), 0.04 um fumed silica and 0.5 um round silica. All used fillers were silane treated. In order to vary the viscosity of experimental composites, the type and content of incorporated fillers were changed. Using a rheometer, a steady shear test and a dynamic oscillatory shear test were used to evaluate the viscosity (η) of resin matrix, and the storage shear modulus (G′), the loss shear modulus (G″), the loss tangent (tanδ) and the complex viscosity (η*) of the composites as a function of frequency ω= 0.1-100 rad/s. To investigate the effect of temperature on the viscosity of composites, a temperature sweep test was also undertaken. Results. Resin matrices were Newtonian fluid regardless of diluent concentration and all experimental composites exhibited pseudoplastic behavior with increasing shear rate. The viscosity of composites was exponentially increased with increasing filler volume%. In the same filler volume, the smaller the fillers were used, the higher the viscosities were. The effect of filler size on the viscosity was increased with increasing filler content. Increasing filler content reduced tanδby increasing the G′further than the G″. The viscosity of composites was decreased exponentially with increasing temperature.

Flowable 복합레진의 slumping 경향과 유변학적 성질

이인복,민선홍,김선영,조병훈,백승호 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.2

본 연구의 목적은 flowable 복합레진의 조작성과 큰 연관이 있는 slumping 경향을 측정하는 방법을 제시하고 이와 관련이 있는 복합레진의 유변학적 특성을 고찰하였다. 5 종의 flowable 복합레진 (Aelitefil Flow:AF. Filtek flow: FF. DenFil flow: DF, Tetric flow:TF and Revolution: RV)이 사용되였다. 주사기에 담긴 일정량의 복합레진을 일정한 속도로 가압할 수 있는 장치를 이용하여 슬라이드글라스 위에 사출한 후 25℃의 실온에서 10초 동안 slumping이 일어나도록 방치 한 후 광중합 하였다. 복합레진의 slumping 경향을 평가하기 위해 원뿔 형 혹은 돔형으로 경화된 시편의 aspect, ratio (밑면의 지름에 대한 높이의 비)를 구하였다. Slumping 경향과 복합레진의 유변학적 성질과의 관련성을 알아보기 위해 Rheometer를 사용하du 각진동수 ω=0.1-100 rad/s의 범위에서 동적진동전단시험을 시행하여 복합레진의 복소점도를 구하였다. 복합레진의 slumping 경향을 비교하기 위해 일원분산분석 및 Turkey's post test를 시행하였고 (α<0.05) 복소점도와 aspect ratio 사이의 관련성을 알아보기 위해 회귀분석을 시행하였다. 결과는 다음과 같다. 1 Slumping 후 aspect ratio를 측정하여 비교한 flowable 복합레진의 slumping 경향은 제품에 따라 큰 차이를 보였다 (AF <FF < DP< TF <RV, P<0.05) 2. Flowable 복합레진은 전단률이 증가함에 따라 점도는 감소하는 pseudoplasticity를 보였고 그 경향은 AF가 가장 컸고 RV가 가장 낮았다. 3. Slumping 저항성은 복소점도가 증가함에 따라 증가하였다. 4 Aspect ratio에 바탕을 둔 slumping 경향의 측정방법은 임상에서 flowable 복합레진의 선택과 새로 개발된 재료의 평가에 유용할 것으로 사료된다. The aim of this study was to develop a method for measuring the slumping resistance of flowable resin composites and to evaluate the efficacy using rheological methodology. Five commercial flowable composites (Aelitefil flow:AF. Filtek flow:FF .DenFil flow:DF. Tetri flow:TF and Revolution:RV) were used. Same volume of composites in a syringe was extruded on a glass slide using a custom-made loading device. The resin composites were allowed to slump for 10 seconds at 25℃ and light cured. The aspect ratio (height/diameter) of cone or dome shaped specimen was measured for estimating the slumping tendency of composites. The complex viscosity of each composite was measured by a dynamic oscillatory shear test as a function of angular frequency using a rheometer. To compare the slumping tendency of composites one way-AN0VA and Turkey's post hoc test was performed for thc aspect ratio at 95% confidence Ievel. Regression analysis was performed to investigate the relationship between the complex viscosity and the aspect ratio. The results were as follows. 1. Slumping tendencv based on the aspect ratio varied among the five materials (AF <FF < DF<TF<RV). 2. Flowable composites exhibited pseudoplasticity in which the complex viscosity decreased with increasing frequency (shear rate). AF was the most significant. RV the least. 3. The slumping tendency was strongly related with the complex viscosity. Slumping resistance increased with increasing the complex viscosity. The slumping tendency could be quantified by measuring the aspect ratio of slumped flowable composites. This method may be applicable to evaluate the clinical handling characteristics of flowable composites.

수직 진동형 Rheometer를 이용한 복합레진의 유변학적 성질의 측정

이인복,조병훈,손호현,이상탁,엄정문 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.6

Objective: The purpose of this study was to investigate the viscoelastic properties related to handling characteristics of composite resins. Methods: A custom designed vertical oscillation rheometer (VOR) was used for rheological measurements of composites. The VOR consists of three parts: (1) a measuring unit, (2) a deformation induction unit and (3) a force detecting unit. Two medium viscous composites, Z100 and Z250 and two packable composites, P60 and SureFil were tested. The viscoelastic material function, including complex modulus E* and phase angle δ, were measured. A dynamic oscillatory test was used to evaluate the storage modulus (E′), loss modulus (E″) and loss tangent (tanδ) of the composites as a function of frequency (ω) from 0.1 to 20 ㎐ at 23℃. Results: The E′and E″ increased with increasing frequency and showed differences in magnitude between brands. The E*s of composites at ω= 2 ㎐, normalized to that of Z100, were 2.16 (Z250), 4.80 (P60) and 25.21 (SureFil). The magnitudes and patterns of the change of tanδof composites with increasing frequency were significantly different between brands. The relationships between the complex modulus E*, the phase angle δ and the frequency ωwere represented by frequency domain phasor form, E* (ω) = E*e^(iδ)= E*∠δ. Conclusions: The viscoelasticity of composites that influences handling characteristics is significant different between brands. The VOR is a relatively simple device for dynamic, mechanical analysis of high viscous dental composites. The locus of frequency domain phasor plots in a complex plane is a valuable method of representing the viscoelastic properties of composites.

대도시 지역주민의 흡연실태와 관련요인 분석

김기열,임상규,서인선,강창열,이병직,남철현,위광복 慶山大學校 保健福祉硏究所 1997 保健福祉硏究 Vol.1 No.-

To collect basic data for deveoping education program for quitting smoking, 1200 subjects were selected randomly living in Seoul, Pusan, Taegu and suburban areas and interviewed about their smoking habits and attitudes from June 20 to July 20, 1997. The result of this study was summarized as follows: 1. In the general characterisics of subjects, the proportion of female was the higher(53.8%) than that of male. Among them, the portion of twenties was 46.6%. in level of educational background, the rate of college graduates was 45.2%, that of high school was 35.7%, that of middle school was 11.5%. The highest proportion by occupation was 38.9% of student. The next was 11.7% of technician, 10.1% of unemployed, 9.4% of office worker and 9.3% of salesman. 2. The proportion of the smokers among subjects was 34.3%. The portion of male smokers was 65.7%, that of female smokers was 7.3%, which had tendency to increased. At the rate of smoking by age, 47.6% in over fifties, 43.6% in forties and 38.7% in thirties were showed that the rate of smoking was the higher in the older age. 3. In the quantity of smoking cigarettes, the rate of one park of cigarettes per day was 52.7%, that of a half pack was 31.1% and that of over two 53.2% and that in female was 59.1% which was highest. 4. In smoking period, the rate of smokers for over 20 years was 29.7%, that for 1-4 years was 25.1% and that for 5-9 years was 20.9%. The variables of age, marital status, educational level and occupation were statistically significant(p<0.01). 5. In the intention of quitting smoking, 48.0% of subjects wanted to stop smoking, 33.4% of them wanted to reduce amounts of cigarettes and 82.8% fo them had positive intention to stop smoking, on the other side 18.6% of subjects did not have any intention to stop smoking. 6. The proportion of subjects who tried to stop smoking was 67.9%. By characteristics, the rate of 67.9% in male, 27.3% in female, 90.9% in under nineteens, 73.6% in married group 69.4% in lower social class, 77.8% in high school graduated and 72.3% in Buddist was the higher than that of other groups. 7. The proportion of subjects who succeeded in quitting smoking was 12.0%. By characteristics, the rate of 40.2% in male, 34.8% in over 50 years old, 19.7% in married group, 15.4% in lower social class, 13.9% in apartment resident, 15.7% in high school graduate and 17.1% in Buddist was the higher than that of other group. 8. In the reason of quitting smoking, 81.0% of subjects had quitted smoking for health, 6.0% of them for religion and 13.0% of them for others. By characteristics, the rate of reason for health was 83.5% in male, 100.0% in age of forties, 84.6% in lower social class. 9. In the affecting factors of quitting smoking, 40.7% of subjects was influenced on family which was the highest, 29.6% of them on health education, 14.8% of them on friend's recommandation, 9.9% of them on medical doctor's advice and 4.9% of them on campaign. By age, twenties was affected by friend, thirties by health education and forties by family. 10. The most affecting independent variable of smoking was sexuality (β=0.42055), age(β=0.25285), drinking (β=0.15425), marital status and health condition(R²=44.8%). These results were shown that education program for quitting smoking especially emphasized injurious to health should be continued in the unit of family, school, office and society, particularly education program for female should be strengthened.

Evidence for novel age-dependent network structures as a putative primo vascular network in the dura mater of the rat brain

Lee, Ho-Sung,Kang, Dai-In,Yoon, Seung Zhoo,Ryu, Yeon Hee,Lee, Inhyung,Kim, Hoon-Gi,Lee, Byung-Cheon,Lee, Ki Bog Medknow PublicationsMedia Pvt Ltd 2015 Neural regeneration research Vol.10 No.7

<P>With chromium-hematoxylin staining, we found evidence for the existence of novel age-dependent network structures in the dura mater of rat brains. Under stereomicroscopy, we noticed that chromium-hematoxylin-stained threadlike structures, which were barely observable in 1-week-old rats, were networked in specific areas of the brain, for example, the lateral lobes and the cerebella, in 4-week-old rats. In 7-week-old rats, those structures were found to have become larger and better networked. With phase contrast microscopy, we found that in 1-week-old rats, chromium-hematoxylin-stained granules were scattered in the same areas of the brain in which the network structures would later be observed in the 4- and 7-week-old rats. Such age-dependent network structures were examined by using optical and transmission electron microscopy, and the following results were obtained. The scattered granules fused into networks with increasing age. Cross-sections of the age-dependent network structures demonstrated heavily-stained basophilic substructures. Transmission electron microscopy revealed the basophilic substructures to be clusters with high electron densities consisting of nanosized particles. We report these data as evidence for the existence of age-dependent network structures in the dura mater, we discuss their putative functions of age-dependent network structures beyond the general concept of the dura mater as a supporting matrix.</P>

Design of Service Logic Run-time Environment for Service Control Point in IMT-2000

Byung Bog Lee,Sung H. Kim 대한전자공학회 1998 CDMA International Conference and Exhibition Vol.- No.-

MANAGER SYSTEM FOR THE SHORT MESSAGE SERVICE CENTER

Byung Bog Lee,Sung Hee Kim 한국통신학회 1997 한국통신학회 워크샵 Vol.- No.-

An Implementation of Agent System for the Short Message Service Center

Byung Bog Lee,Sung Hee Kim 대한전자공학회 1997 CDMA International Conference and Exhibition Vol.- No.-

Manager System for the Short Message Service Center

Byung Bog Lee,Sung Hee Kim 대한전자공학회 1997 대한전자공학회 워크샵 Vol.1997 No.-