Self-etching primer를 이용하여 접착된 교정용 브라켓의 전단결합강도

안윤표,김효영,전영미,김정기 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.1

본 연구는 6세대 교정용 접착 시스템인 Transbond Plus Self-Etching Primer(3M/Unitek Dental Products, Monrovia, Calif)를 이용하여 법랑질면에 브라켓을 접착하는 방법과, 통상적인 산부식 방법에 의해 브라켓을 접착한 경우의 전단결합강도 차이를 비교·평가하고, self etching primer를 이용하여 브라켓을 접착할 때 치면에 존재하는 수분이 브라켓의 전단결합강도에 미치는 영향에 관하여 조사하였다. 37% 인산용액과 Self-Etching Primer를 잉용하여 법랑질을 표면 처리하고 Transbond XT를 이용하여 브라켓을 치면에 부착하였다. 또한 수분의 존재에 따른 전단결합강도의 차이를 평가하기 위해 인공타액을 치면에 도포후 Self-Etching Primer를 사용하여 브라켓을 부착한 후 30분과 24시간에 따른 전단결합강도를 비교 평가하여 다음과 같은 결론을 얻었다. 1. Self-etching primer군에서 건조군과 습윤군의 전단결합강도는 37%인산처리군의 결합강도보다 낮았다(p<0.05). 그러나 Self-etching primer군의 전단결합강도는 임상적으로 유용한 수준의 이상이었다. 2. 모든군에서 24시간군의 전단결합강도가 30분군의 전단결합강도보다 높았으며(p<0.05), 이는 브라켓 접착후 일정시간의 경과가 결합강도를 증가시켜 줌을 알 수 있었다. 3. Self-etching primer군에서 습윤군의 전단결합강도는 건조군보다 높은 경향이었으나 통계적 유의성은 인정되지 않았다(p<0.05). 4. ARI 점수의 비교결과 인산처리군에서는 0점과 1점의 빈도가 높았으며, Self-etching primer 건조군과 습윤군에서는 2점과 3점의 빈도가 높아(p<0.05) Self-etching primer군이 인산처리군보다 법랑질-레진 접착계면부위에서의 파절이 많이 일어남을 알 수 있었다. The purpose of this study was to evcaluate the effects of a self-etching primer on the shear bond strength of orthodontic brackets and on the failure pattern of bracket-adhesive interfaces in dry or wet condition. Brackets were bonded to extracted human teeth according to one of three experimental protocols. In the Group P, teeth were etched with 37% phosphoric acid. After the Transbond XT Primer was applied onto the etched surfaces, the brackets were bonded with Transbond XT(3M, Unitek, Monrovia, Calif) and light cured for 40 seconds. In the Group SD, a self-etching primer(3M, Unitek, Monrovia, Calif) was placed on the enamel for 3 seconds and gently evaporated with air, as suggested by the manufacturer. The brackets were then bonded with Transbond XT as in the Group P. In the Group SW, artificial saliva was applied to the enamel surface for 10 seconds to allow complete hydration of the surface before application self-etching primer. The brackets were then bonded following the procedures of Group SD. Each group was divided into 2 sub-groups(0.5h, 24h) according to debonding time shear bond strengths were measured by Instron universal testing machine. After debonding, the teeth and brackets were examined under scanning electron microscope and assessed with the adhesive remnant index. The result obtained were summarized as follows ; 1. The shear bond strengths were high enough to use clinically in all testing groups, but the shear bond strengths of group SD and SW were significantly lower than Group P(p<0.05). 2. With respect to comparison of debonding time, 24h debonding samples exhibited heigher shear bond strength than 0.5h debonding samples in Group P, SD and SW(p<0.05). 3. In the self etching primer groups(Group SD and Group SW), there was no significant difference in mean shear bond stredifference in mean shear bond strength between under dry and wet state(p>0.05). 4. There was a greater frequency of ARI score of 0 and 1 with the Group P. On the other hand, there was a higher frequency of ARI scores of 2 and 3 with Group SD and Group SW(p<0.05).,

횡단보도 보행 잔여시간제공에 의한 보행행태의 변화에 관한 연구

오윤표,안영종,정순현 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.29 No.1

Recently, the countdown signal was introduced to enhance the pedestrian environment of crosswalk. However, research is still insufficient as to how comfortable and safe it is compared to existing signals as well as the most suitable location for installment. The statistical significance of the extent of change of pedestrian moving time on the graph was analyzed through a paired t-test, a before-after study on pedestrian crossing patterns and χ^(2)-test of both groups. Results form the application of the proposed analysis of the study showed that on introduction of the countdown signal, pedestrians will cross more amiably and comfortably than before.

2004년도 도시별 교통문화지수 실태조사

오윤표,안영종 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

부산시 고령자의 통행행태에 관한 연구

오윤표,안영종,김은정 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.29 No.1

The purpose of this study os to analyze the elderly's travel behavior and to measure the factors affecting their travel mode choice. Questionnaire survey was conducted for this study. It is assumed that the elderly is over 65 years old for this study. The major results of this study are as follows:(1) Because driving alone is very expensive travel mode, bus is considered as main travel mode for the elderly over 65 years old. (2) The friendship, recreation, an medical treatment are significant travel purpose. It was showed that the elderly's travel pattern is irregular. (3) Going up and down of stairs are the most important restriction for the elderly's travel.

U-Turn의 적정신호시간 모형구축에 관한 연구

오윤표,안영종,이영빈 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

In metropolitan, main streets manages 60-80% of the whole traffic in Korea even though its limited area and short extension. Main streets in urban has suffered congestion and a falling-off in capability of transportation due to its frequent discontinuity and disconnection. Especially Left-turn traffic mainly generates a shortage of fluidity in intersection although most intersection adopts Left-turn because of the peculiarity of traffic flows. To breakthrough this deterioration, U-turn system goes into effect in intersection of most main streets by reducing Left-turn phase or banning Left-turn at specific intersections to increase the fluidity of main direction. However, U-turn system lacks continuity and reveals security deficits because its legal basis and safety standard are not definitive. Therefore, this study, firstly, investigates the special characteristics of U-turn system, analyzes its effects based on the case of Busan city making the survey of drivers' awareness on U-turn. Then, secondly, This study aims to suggest more efficient and executive operating program for U-turn system by constructing proper Signal time model for U-turn.

Analysis of Polycyclic Aromatic Hydrocarbons in Ambient Aerosols by Using One-Dimensional and Comprehensive Two-Dimensional Gas Chromatography Combined with Mass Spectrometric Method: A Comparative Study

Ahn, Yun Gyong,Jeon, So Hyeon,Lim, Hyung Bae,Choi, Na Rae,Hwang, Geum-Sook,Kim, Yong Pyo,Lee, Ji Yi Hindawi 2018 Journal of analytical methods in chemistry Vol.2018 No.-

<P>Advanced separation technology paired with mass spectrometry is an ideal method for the analysis of atmospheric samples having complex chemical compositions. Due to the huge variety of both natural and anthropogenic sources of organic compounds, simultaneous quantification and identification of organic compounds in aerosol samples represents a demanding analytical challenge. In this regard, comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) has become an effective analytical method. However, verification and validation approaches to quantify these analytes have not been critically evaluated. We compared the performance of gas chromatography with quadrupole mass spectrometry (GC-qMS) and GC×GC-TOFMS for quantitative analysis of eighteen target polycyclic aromatic hydrocarbons (PAHs). The quantitative obtained results such as limits of detection (LODs), limits of quantification (LOQs), and recoveries of target PAHs were approximately equivalent based on both analytical methods. Furthermore, a larger number of analytes were consistently identified from the aerosol samples by GC×GC-TOFMS compared to GC-qMS. Our findings suggest that GC×GC-TOFMS would be widely applicable to the atmospheric and related sciences with simultaneous target and nontarget analysis in a single run.</P>

Molecular cloning and functional characterization of a glucose transporter (CsGLUT) in Clonorchis sinensis

Ahn, Seong Kyu,Cho, Pyo Yun,Na, Byoung-Kuk,Hong, Sung-Jong,Nam, Ho-Woo,Sohn, Woon-Mok,Ardelli, Bernadette F.,Park, Yun-Kyu,Kim, Tong-Soo,Cha, Seok Ho Springer-Verlag 2016 Parasitology research Vol.115 No.1

<P>A complementary DNA (cDNA) encoding a glucose transporter of Clonorchis sinensis (CsGLUT) was isolated from the adult C. sinensis cDNA library. The open reading frame of CsGLUT cDNA consists of 1653 base pairs that encode a 550-amino acid residue protein. Hydropathy analysis suggested that CsGLUT possess 12 putative membrane-spanning domains. The Northern blot analysis result using poly(A)(+)RNA showed a strong band at similar to 2.1 kb for CsGLUT. When expressed in Xenopus oocytes, CsGLUT mediated the transport of radiolabeled deoxy-D-glucose in a time-dependent but sodium-independent manner. Concentration-dependency results showed saturable kinetics and followed the Michaelis-Menten equation. Nonlinear regression analyses yielded a Km value of 588.5 +/- 53.0 mu M and a Vmax value of 1500.0 +/- 67.5 pmol/oocyte/30 min for [1,2-H-3]2-deoxy-D-glucose. No trans-uptakes of bile acid (taurocholic acid), amino acids (tryptophan and arginine), or p-aminohippuric acid were observed. CsGLUT-mediated transport of deoxyglucose was significantly and concentration-dependently inhibited by radio-unlabeled deoxyglucose and D-glucose. 3-O-Methylglucose at 10 and 100 mu M inhibited deoxyglucose uptake by similar to 50 % without concentration dependence. No inhibitory effects by galactose, mannose, and fructose were observed. This work may contribute to the molecular biological study of carbohydrate metabolism and new drug development of C. sinensis.</P>

Inhibition of PDGF-BB-lnduced MAP Kinase (ERK1/2) Activation in Rat Aortic Vascular Smooth Muscle Cells by NQ12

Yun YeoPyo,Ahn HeeYul,Pyo HyungBea,Jeon JinSeon 대한약학회 2002 大韓藥學會 總會 및 學術大會 Vol.2002 No.1

Excess mortality among patients on dialysis: Comparison with the general population in Korea

( Hyung Yun Choi ),( Myoung Hee Kim ),( Hyun Wook Kim ),( Jung Pyo Lee ),( Jeong Hwan Lee ),( Jung Tak Park ),( Kyoung Hoon Kim ),( Hyeong Sik Ahn ),( Hoo Jae Hann ),( Dong Ryeol Ryu ) 대한신장학회 2014 Kidney Research and Clinical Practice Vol.33 No.2

Background: Although patients with end-stage renal disease (ESRD) experienceexcess mortality compared with the general population, the standardized mortalityratio (SMR) for Korean patients on dialysis has not yet been investigated. In thisstudy, we evaluated the SMR among all Korean ESRD patients on maintenancedialysis in 2009 and 2010, and compared it according to age categories, sex, anddialysis modality. Methods: We used data from all patients on maintenance dialysis between January 1,2009 and December 31, 2010 in Korea using the database of the Korean HealthInsurance Review and Assessment Service, and the SMR was determined by calculatingof the ratio between the number of actual deaths and expected deaths. Results: A total of 45,568 patients in 2009 and 48,170 patients in 2010 were includedin the analysis. The overall age- and sex-adjusted SMR was 10.3 [95% confidenceinterval (CI), 10.0-10.6] in 2009 and 10.9 (95% CI, 10.7-11.2) in 2010. The SMR forfemales was much higher than for males. The SMR gradually decreased withincreasing age groups. The overall SMR for maintenance hemodialysis patients waslower than that of peritoneal dialysis patients. Conclusion: The SMR among Korean ESRD patients is likely to be higher than in othercountries. Further evaluation is needed to attempt to improve the outcomes.

Effects of local wall thinning on plastic limit loads of elbows using geometrically linear FE limit analyses

Kim, Yun-Jae,Kim, Jonghyun,Ahn, Joonghyuk,Hong, Seok-Pyo,Park, Chi-Yong Elsevier 2008 Engineering fracture mechanics Vol.75 No.8

<P><B>Abstract</B></P><P>This paper provides closed-form plastic limit load solutions for elbows under in-plane bending and internal pressure, via three-dimensional (3D), geometrically linear FE limit analyses using elastic-perfectly plastic materials. Wide ranges of elbow and thinning geometries are considered. To investigate the effect of the axial thinning length on limit loads systematically, two limiting cases are considered; a sufficiently long thinning, and the circumferential part-through surface crack. Closed-form plastic limit load solutions for wall thinning with intermediate longitudinal extents are then obtained from these two limiting cases. The effect of the axial extent of wall thinning on plastic limit loads for elbows is highlighted by comparing that for straight pipes. Although the proposed solutions are developed for the case when wall thinning exists in the center of elbows, it is also shown that they can be applied to the case when thinning exists anywhere within the elbow.</P>