유치와 영구치에서 치과용 접착제의 전단결합강도

최진영,최남기,박영준,최충호,양규호 大韓小兒齒科學會 2007 大韓小兒齒科學會誌 Vol.34 No.4

The objective of this study was to compare the shear bond strengths of five adhesive systems to the enamel and dentin of primary and permanent teeth. Fifty noncarious primary and fifty permanent teeth were collected and stored in an 0.1% thymol solution at room temperature after extraction. The tested adhesives were: Adper Scotchbond Multi-purpose Plus Adhesive (SM) Adper Single bond 2 (SB), Clearfil SE Bond (SE), Adper Prompt L-Pop (PL), G-Bond (GB). For the shear bonding test, the labial and lingual surfaces of primary and permanent teeth were used. To obtain a flat surface, the labial and lingual surfaces of the teeth were sanded on SiO₂with number 600 grit and then divided into 20 groups of 10 surfaces each. All samples were theromocycled in water 5℃ and 55℃ for 1000 cycles. The results were as follows: 1. For primary enamel, shear bond strengths of SM and SB were significantly higher than that of SE and also SM, SB, and PL were higher than GB(p<0.05). 2. For primary dentin, there were no significant differences among the shear bond strengths of any other bonding systems except differnece between SE and GB. 3. For permanent enamel, SB showed significantly higher mean shear bond strength than those of any other bonding systems(p<0.05). 4. For permanent dentin, SM showed significantly higher mean shear bond strength than that of PL and GB(p<0.05). 5. Between the primary enamel and dentin, there were significant differences in SM, SB, and GB, whereas there was statistically significant difference in PL between the permanent enamel and dentin(p<0.05). 6. Between the primary and permanent teeth on enamel, there were no significant differences among all bonding systems, whereas there were statistically significant differences in SM and SB between the primary and permanent teeth on dentin(p<0.05). 본 연구에서는 최근에 개발된 치과용 접착제를 대상으로 유치와 영구치의 법랑질과 상아질에 대한 결합력을 비교 평가하여 입상에서 상아질 접착제를 적절하게 선택하는데 도움을 주고자 시행하였다. 실험재료로 Adper Scotchbond Multi-purpose Plus Adhesive (SM; 3M ESPE,USA),Adper Single bond 2 (SB; 3M ESPE,USA),Clearfil SE Bond (SE; Kuraray Medical Inc.,Japan),Adper Prompt L-Pop (PL; 3M ESPE,USA),G-Bond (GB:GC Cooperation Toyko,Japan)를 이용하여 전단결합강도를 평가하여 다음과 같은 결과를 얻었다. 1. 유치 법랑질에서 전단결합강도는 SM이 28.47±7.93 MPa로 가장 높았고 SB (28.18±6.84),PL (24.02± 6.14),SE (21.70±6.56),GB (17.70±6.68) 순이었다. SM과 SB는 SE보다 통계적으로 유의하게 높은 결합 강도를 보였으며,SM,SB,PL은 GB보다 높았다(p<0.05). 2. 유치 상아질에서 전단결합강도는 SE가 28.72±14.44MPa로 가장 높았고,PL (20.10±6.13),SM 07.72± 10.65),SB (15.48±2.66),GB (10.10±5.45) 순이었으며 SE와 GB간 에는 유의한 차이가 있었으나,다른 군 들 간에는 유의한 차이가 없었다. 3. 영구치 법랑질에서의 전단결합강도는 SB가 28.36±5.68 MPa로 가장 높았고 SM (22.77±4.63), PL(22.05 士6.57),SE (21.74±4.62),GB (15.60±6.75)순이었다. SB는 다른 접착제보다 통계적으로 유의하게 높은 결합력을 나타냈으며,GB는 가장 낮은 결합력을 보였다(p(0.05). 4. 영구치 상아질에서의 전단결합강도는 SM이 28.22±5.56 MPa로 가장 높았고,SB (21.68±7.44),SE (20.13 ±9.88),GB (14.30±6.81),PL (14.18±5.88)순이었으며,SM은 PL,GB와 유의한 차이가 있었다(p<0.05). 5. 유치의 법랑질과 상아질 간에는 SM,SB,GB에서 유의한 차이가 있었고,영구치 법랑질과 상아질 간에는 PL에서 유의한 차이가 있었다(p<0.05). 6. 유치 법랑질과 영구치 법랑질 간에는 모든 접착제에서 유의한 차이가 없었으나,유치 상아질과 영구치 상아질 간에는 SM과 SB에서 유의한 차이가 있었다(p<0.05).

GMAHN 환경에 적응하는 에러 복구기능을 이용한 AODV 라우팅 프로토콜

정찬혁,오세덕,배진승,이기원,장양근,이광배,김현욱,유충렬,하재승 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

Mobile nodes in ad hoc mobile networks typically communicate over wireless channels and are capable of movement. These are networks that support multihop communication and can be formed on a temporary basis. This paper proposes a solution that allows mobile nodes to access the wired Internet and to roam from base station to base station. And we also develop the efficient method that adapts in Global MANET which can be changed over time. It is observed that we can reduce not only error detection time but also network load, thus increasing the data reception rate in Global MANET Environment.

부산, 울산, 경남지역 직업병감시체계에서 나타난 수지진동증후근의 역학적 특성

최영희,유철인,이지호,이충렬,이헌,김영욱,채창호,고상백,김은아,이유진,김양호 大韓産業醫學會 2003 대한직업환경의학회지 Vol.15 No.3

목적: 국내에서도 국소진동에 의한 수지진동증후군이 다수 있을 것으로 추정하나 최근에 이에 대한 보고가 적어 부·울·경 직업병감시체계를 통하여 수지진동증후군에 대한 환례를 수집하여 이의 역학적 특성을 밝히고자 본 연구를 실시하였다. 방법: 2001년 44월부터 2002년 12월까지 부산, 울산, 경남지역에 있는 종합병원 9곳을 통하여 특수 건강진단과 산업의학과 외래를 방문한 근로자를 대상으로 진동폭로에 대한 설문조사를 실시하고 이들중에서 수지진동으로 인한 증상을 호소하는 근로자는 이학적 검사와 Stockholm workshop scale을 이용하여 수지진동증후군이 있는지 평가하였다. 결과: 남자 188명, 여자 4명 등 총 192례의 수진진동증후군이 의심되는 환례를 수집하였으며, 업종별로는 조선업에 종사하는 근로자들이 가장 많았다. 국소진동의 주된 폭로원은 그라인더가 가장 많았으며, 혈관장해로 인한 증상보다 감각신경성 장해로 인한 증상을 많이 호소하였다. 결론: 전국적으로 조선업종의 그라인더 사용자를 중심으로 많은 수의 수지진동증후군의 환자가 있을 것으로 추정되며, 이들에 대한 예방대책을 마련하기 위하여 전국규모의 정확한 유병률 조사 및 실태파악이 필요한 것으로 판단된다. Objects: The objectives of this study were to estimate the epidemiologic characteristics of hand-arm vibration syndrome (HAVS) due to occupational exposure of hand transmitted vibration and to identify the occupations and industries where such exposures arises, and the main sources of exposure. Methods: In April 2001 the Busan, Ulsan, and Kyung-Nam Province occupational disease surveillance system was established to measure the incidence and prevalence of work-relatd HAVS and other occipational diseases in these Korean provinces. Occupational physicians of nine hospitals in Busan, Ulsan, and Kyung-nam Province were involved in this project between April 2001 and November 2002. Physicians collected information through questionnaires and interviews. Information gathered included age, occupation, types of vibration tools used and presence of subkective symptoms such as vibration-induced white finger (VWF), numbness and tingling. Results: A total 192 cases were reported with 188 males and 4 females. The shipbuilding industry was the most common type of industry and grinders were the most common source of exposire. Symptoms of neurological disorder were more common than those of vascular disprder. Conclusions: The authors concluded that exposure to hand transmitted vibration is common and that HAVS is one of the most common occupational diseases in Korea. However, the range and extent of hand transmitted vibration and the overall prevalence of HAVS in Korea is still unknown. More extensive research on this syndrome in order to priorite necessary preventive measures is required.

Nano phosphors for PDP RGB and their PL characteristics

Yang, Choong-Jin,Choi, S.D.,Park, E.B.,Park, J.I.,Lee, Y.J. 한국정보디스플레이학회 2007 Journal of information display Vol.7 No.2

RF plasma and aerosol nano process were developedfor a volume production of nanoscale phosphors. R, G, and B PDP phosphors were synthesized and the characteristics were optimized through the proprietary power treatments. PL intensities were confirmed to be enhanced up to 70% of that of present commercial phosphors.

Magnetic simulation of Nd₂Fe₁₄B / α-Fe nanocomposite magnets in 2D and 3D nanoscale

Choong Jin Yang,Jong Soo Han,Eon Byeung Park 한국자기학회 2005 한국자기학회 학술연구발표회 논문개요집 Vol.15 No.2

Pulmonary Toxicity and Recovery from Inhalation of Manual Metal Arc Stainless Steel Welding Fumes in Rats

Yang, Mi-Jin,Kim, Jin-Sung,Yang, Young-Su,Cho, Jae-Woo,Choi, Seong-Bong,Chung, Yong-Hyun,Kim, Yong-Bum,Cho, Kyu-Hyuk,Lim, Chae-Woong,Kim, Choong-Yong,Song, Chang-Woo Korean Society of ToxicologyKorea Environmental Mu 2008 Toxicological Research Vol.25 No.3

The objectives of this study were to examine the lung injury and inflammation caused by manual metal arc stainless steel(MMA-SS) welding fume inhalation and to evaluate the recovery process. Sprague-Dawley rats were exposed to MMA-SS welding fumes for 2 h per day in a whole-body exposure chamber, with a total suspended particulate(TSP) concentration of $51.4{\pm}2.8mg/m^3$(low dose) or $84.6{\pm}2.9mg/m^3$(high dose) for 30 days. The animals were sacrificed after 30 days of exposure as well as after a 30-day recovery period. To assess the inflammatory or injury responses, cellular and biochemical parameters as well as cytokines were assayed in the bronchoalveolar lavage fluid(BALF). MMA-SS welding fume exposure led to a significant elevation in the number of alveolar macrophages(AM) and polymorphonuclear cells(PMN). Additionary, the values of $\beta$-n-acetyl glucosaminidase($\beta$-NAG) and lactate dehydrogenase(LDH) in the BALF were increased in the exposed group when compared to controls. After 30 days of recovery from exposure, a significant reduction in inflammatory parameters of BALF was observed between the exposed and recovered groups. Slight, but significant elevations were noted in the number of AM and PMN in the recovered groups, and AM that had been ingested fume particles still remain in the lungs. In conclusion, these results indicated that welding fumes induced inflammatory responses and cytotoxicity in the lungs of exposed rats. Fume particles were not fully cleared from lungs even after a 30-day recovery period.

Computer Simulated Magnetic Properties of Nd2Fe14B/α-Fe Nanocomposite Magnets

Choong Jin Yang,Jong Soo Han,Eon Byeung Park 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.I

Micromagnetic models of assemblies of randomly oriented, exchanged coupled nanocrystals consisting of magnetically hard Nd2Fe14B and very soft alpha Fe have been simulated. The modeling of two-dimensional chessboard consisted of 50 vol.% hard and 50 vol.% soft nanocrystals with the size varying from 5, 10, 25, to 50 nm. Hysteresis curves of each model system were obtained by solving the Landau-Lifshitz-Gilbert equation by time integration of the stiff differential equations. The simulation was focused on the effect of domain size and distribution in each nano crystal of fixed size. Eventually the simulated results were compared with magnetic properties obtained from experimental results of NdFeNbB based magnetic alloys showing the identical grain sizes to the simulated model. The present study exhibited the important role of soft phase in terms of volume fraction and arrangement of the phase.

Nanoparticle Phosphors Synthesized by Inductively Controlled Plasma Process for Plasma Based Display

Yang, Choong-Jin,Park, Jong-Il,Choi, Seung-Dueg,Park, Eon-Byeong,Lee, Young-Joo The Korean Ceramic Society 2008 한국세라믹학회지 Vol.45 No.7

Optimized volume production of nanoscale phosphor powders synthesized by radio frequency (RF) plasma process was developed for the application to plasma display panels. The nano powders were synthesized by feeding the both solid and liquid type precursors, and nanoparticle phosphors were characterized in terms of particle size, shape, and photoluminescence (PL) intensities. Computer simulation was performed in advance to determine the process parameters, and nano phosphors were evaluated by comparing with current commercial micron-sized phosphor powders. Practical feeding of both solid and liquid type precursor was proved to be effective for volume production.The developed process showed a potential as a production method for red, blue and green phosphor although the PL intensity still needs further improvement.

Tunneling magnetoresistance of Co granulars in AlN

Choong Jin Yang,Min Zhang,Jong Soo Han,Zhi Dong Zhang 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.43 No.51

Magnetic transport phenomena in rf sputtered AlN/Co type ten-layered discontinuous lms of nanoscaled [AlN(3 nm)/Co(t nm)]10 with tCo = 1.0 2.0 nm have been investigated. The nanostructures and tunneling magnetic resistance of the samples are strongly dependent on the thickness of the Co layer. Negative tunneling magneto-resistance due to the spin-dependent transport has been observed along the current-in-plane conguration in the samples having the Co layers below 1.6 nm thick. When the thickness of Co layer was less than 1.2 nm, randomly oriented granular Co particles were completely isolated and embedded in an amorphous AlN matrix, and the lms showed the superparamagnetic behavior with a high MR value of /0 = 3.5 %. As tCo increases, a transition from the regime of co-existence of superparamagnetic and ferromagnetic behaviors to ferromagnetic behavior was observed. The tunneling barrier \decay length for tunneling" for lms having a Co layer thickness from 1.4 to 1. 6 nm was measured to be in the range from 0.004 to 0.021 A..1. An enhanced TMR was observed after annealing which is subscribed to an increase of about 100 % in activation energy for tunneling.

The alteration of components in the fermented Hwangryunhaedok-tang and its neuroprotective activity

Yang, Hye Jin,Weon, Jin Bae,Lee, Bohyoung,Ma, Choong Je Medknow Publications Pvt Ltd 2011 Pharmacognosy magazine Vol.7 No.27

<P><B>Background:</B></P><P>Hwangryunhaedok-tang is a traditional herbal prescription that has sedative activity, hypotensive and anti-bacterial effects.</P><P><B>Objective:</B></P><P>In this study, we investigated the alteration of contents of components in Hwangryunhaedok-tang, antioxidant activity and neuroprotective activity by fermentation with <I>Lactobacillus acidophilus</I> KFRI 128.</P><P><B>Materials and Methods:</B></P><P>Contents of three marker compounds (geniposide, berberine and palmatine) and unknown compounds in the Hwangryunhaedok-tang (HR) and the fermented Hwangryunhaedok-tang (FHR) were measured and compared using the established high-performance liqued chromatograph coupled with a photodiode (HPLC-DAD) method. The antioxidant activity of HR and FHR were determined by DPPH free radical and hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) scavenging assay. Also, the neuroprotective activities of HR and FHR against glutamate-induced oxidative stress in a mouse hippocampal cell line (HT22) were evaluated by MTT assay.</P><P><B>Results:</B></P><P>The contents of geniposide and palmatine were decreased but the content of berberine was increased in the FHR. And the contents of unknown compounds (1), (2), (3), (4) and (5) in the HR were altered by fermentation. Electron donating activity (EDA, %) value of FHR was higher than HR for DPPH radical scavenging activity and H2O2 scavenging activity, respectively. In the MTT assay, FHR showed more potent neuroprotective activity than HR by 513.90%.</P><P><B>Conclusion:</B></P><P>The FHR using microorganism could convert compounds in HR and enhance the antioxidant and neuroprotective activity.</P>