크롬(Ⅵ)의 체내 흡수와 소실속도에 관한 연구

김현영,이성배,임철홍,이권섭,정용현,이종성,한정희,전윤석,황호순,이용묵 한국산업위생학회 2003 한국산업보건학회지 Vol.13 No.1

The CrO3 mostly used in plating. metal surface disposal, leather, cosmetic manufacturing, as an experiment material by repeatedly inhaling and exposure the male S.D. rats at a 0.00, 0.2., 0.50, 1.25 mg/㎡ concentration(particle size: 0.5-0.5 aerosol)6hours a day, 5day a week in 13weeks comparing with 2weeks, 8weeks of recovery group about the noxiousness of the experiment animal and the reduce scale of the CrO3 in the internal organ especially in blook and respiratory organ with the period of convalescent and clearance. The experiment results which we received are as follows. 1. In blood the RBC, HGB and HCT experiment, rats with 0.20, 0.50 mg/㎡ concentration showed that there were some decreases but not dependent. The kidneys absolute weight compared with control group was reduced intentionally(p〈0.05) and the lungs absolute weight compared with control group showed intentional increase(p〉0.05). 2. After the exposure of the experiment material, the whole blook, l\blood plasma and red blood cell in blood by (x): the period of convalescent, per (y); the decreasing of Cr concentration, was y=66.51 e -0.057x, y=67.2 e-0.101x, y=70.01 e-0.030 in 0.50 mg/㎡ exposure concentration by calculating the clearance coefficient of correlation, and the half life (day)was estimated 12.0, 6086, 23.0 each. 3, After the exposure of the experiment material, the experiment animals lung, liver and kidneys by(x); the period of convalescent, per (y); the decreasing of Cr conentration, was y=1808 e-0.00493x, y=12.02e-0.0297x, y=67.61 e-0.0292x in 0.50mg/㎡ exposure concentration by calculating the clearance coefficient of correlation, and the half life(day)was estimated 140.6, 23.3, 23.7, each, and including lung, liver with all of the experiment internal organs, the Cr clearance decreased as the exposure concentration increased.

온도변화가 교정용 니켈-티타늄 호선의 상-변태에 주는 영향

이유현,임범순,이용근,김철위 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

The purpose of this study was to evaluate the change of phase transformation and mechanical properties of orthodontic Ni-Ti wire by temperatures changes (0 ℃, 20 ℃, 37 ℃ and 60 ℃) using three-point bending tests and to investigate the phase transformation behavior by microstructure analysis and X-ray diffraction in greater detail. The transition temperature range (TTR) of orthodontic Ni-Ti wires was analysed by DSC for the reference of proportion of martensite to austenite matrix. From this study the following results were obtained. In SM group, as the temperature decreased to 20 ℃ and 0 ℃, superelasticity loop showing at 37 ℃ in load-deflection curve disappeared and the critical load of stress induced martensite transformation decreased (p<0.01). In SE group, the load increased as the temperature increased as the temperature increased under certain temperature (p<0.01). From the microscope, the proportion of stripe-shaped martensite plate to austenite matrix was higher in NEO, active martensite alloy, than OPTI, the active austenite alloy. The (002) peak indicating martensite phase clearly appeared when the temperature decreased to -20 ℃ in NEO from the X-ray diffraction spectra. This study indicated that mechanical properties of orthodontic Ni-Ti wires were substantially affected by temperature and we could expect the biological response in periodontal ligament by load fluctuation of wires tied in bracket induced by temperature variation.

TiO₂미세분말 제조에 관한 연구

이광래,안순철,송근호,김종수 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

역마이셀 기법에 의하여 TiO₂ 분말을 제조하였으며, TiO₂ 분말 제조에 미치는 공정변수들인 계면활성제의 종류 및 보조계면활성제가 생성입자의 입도분포에 미치는 영향을 규명하였다. 비이온계면활성제인 Span 80을 사용하였을 경우에는 입도분포가 unimodal형태였으나, 음이온계면활성제인 Aerosol-OT(AOT)를 사용하였을 경우, bimodal형태를 나타내었다. 에탄올(ethanol)을 cosurfactant로 첨가한 계로 부터 생성된 입자는 평균입경이 0.12㎛ 으로서 미세할 뿐아니라 입도분포도 매우 좁은 것을 알 수 있다. Titanium dioxide (TiO₂) fine particles were produced by the reverse micelle technique. The effects of process variables such as surfactant and cosurfactant on particle size distribution were investigated. The particle size distribution curve was unimodal for a nonionic surfactant (Span80), but was bimodal for an anionic surfactant (AOT). The addition of ethanol as a cosurfactant resulted in narrow particle size distribution and 0.12㎛ of smaller average particle diameter.

배양조건에 따른 치수세포 RPC-C2A의 특성 : 배양용기 및 BMP 처리 Culture Ware and BMP Treatment

이용근,임범순,김철위 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.4

Odontoblasts are highly differentiated cells aligned at the periphery of the dental pulp. Pulp tissue responds to injury by generating reparative dentine elaborrated by odontoblast-like cells that differentiated from pulp cells. In vitro, dental pulp cells cultured under certain conditions are able to express typical markers of cell differentiation; however, no culture sysem can simulates clinical pulp response. The purpose of this study was to evaluate the effect of culture ware and BMP on the seeding. growth sne differentiation of pulp derived cell line, RPC-C2A. Large pore-sized PET membrane (0.4 ㎛, Cell Culture Insert, BD Science, USA), rhBMP-4 (R & D Systems, USA) and polystyrene modified by vacuum-gas plasma treated culture surface (Primaria, BD Science, USA) were tested. RPC-C2A cells are maxillary incisor pulp cells from male Wistar rats (Kasugai el al., 1988). Cells were cultured on a traditional polystyrene culture ware (PS), transparent PET membrane (MI), Insert + rhBMP-4 (20 ng/ml, MB), and Primaria culture ware (PM) up to 21 days. Culture media was 10% FBS added DMEM with 10 mM β-glycerophosphate, 10^-8 M dexamethasone, 50 ㎍/ml ascorbic acid and 50 mM sodium fluoride. Formation of multilayered cell layer and mineral nodule was determined with a phase contrast microscope and EDXA. There were no differences in cell attachment and growth rate among four culture conditions up to three-days culture. Multilayered cells were observed after six-days culture, and mineral nodules were observed in MB condition after seven-days culture. After nine-days culture, mineral nodules were observed in PS, and new nucleation of mineral nodules was prominest in MI and MB conditions. Exfoliation of cells from the dish was observed in PS after 13-days culture, and vaeuoles were formed in MI after 19-days culture. After 21-days culture, cell death was accompanied by increase of mineral nodules in MB. Growth and development of pulp cells were influenced by the culture ware and BMP. In MB condition, the duration for the formation of multilayered cells and mineral nodule was shortened compared to other conditions.

열탈착 분석법에 의한 Pt(111) 표면위의 NO와 CO의 흡착

이순보,박종윤,곽현태,부진효,강용철 성균관대학교 1992 論文集 Vol.42 No.2

The adsorptions of nitric oxide and carbon monoxide on Pt(111) surfaces have been studied by using LEED, AES, and TDS(Thermal Desorption spectroscopy). The adsorbed species of NO is predominantly molecular on the Pt(111) surface at room temperature. A main desorption peak of TDS is attributed to the molecular adsorption at 360K. With increasing No exposures, a shoulder peak at 480K which may be attributed to the defect site adsorption is appeared. The desorption rate order for No desorption is 1st order and the desorption energy for NO calculated by Redhead equation assuming pre-exponential factor v_1=10^13 sec^-1 is 21.7Kcal/mol. The adsorption of carbon monoxide is also molecular on Pt(111) surface at room temperature. The TDS results showed only a single broad peak at 460K, which is attributed to molecular adsorption. The desorption order for CO desorption is 1st order as well as NO and the desorption energy for CO is 28Kcal/mol.

치과용 알지네이트 인상재의 국산화 및 개량에 관한 연구 : Ⅰ. 조성이 특성에 주는 영향

이용근,임범순,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.3

Dental alginate impression materials have become widely used to take study impression for orthodontic and other purposes and, to a limited extent, have been applied in inlay, crown and bridge procedures. The alginate impression products have good elastic properties and compare well with the agar materials. The final purpose of this serial study is to develop a domestic dental alginate impression material which is proper for use in Korea. The final purpose of this first year study was to find a proper composition of alginate impression material, which shows appropriate mechanical properties and high biocompatibility. Several kinds of experimental alginate impression materials were prepared by mixing sodium alginate, calcium sulfate dihydrate, diatomaceous earth as filler, borax, magnesium oxide, potassium chloride, sodium acetate, sodium phosphate, zinc fluoride and zinc oxide in varied proportions. Texture of powder and mixture, flexibility, recovery from deformation, setting time, compressive properties, compatibility with dental stone, reproduction of detail and cytotoxicity by MTT assay and neutral red inhibition zone of mixed experimental and commercial alginate impression materials were tested according to the specifications of Korean Food and Drug Administration, Korean Dental Association No. 8, American Dental Association No. 18 and International Standardization Organization 1563 (1990). From this study, proper compositions of experimental alginate impression material which showed flexibility of 5∼20% (in accordance with the specification), and proper setting time of 1.5∼5 minutes was found. Although the property of recovery from deformation was lower than that of the specification, these values were similar to those of commercial alginate impression materials. The compressive strength was in accordance with the specification of more than 0.35 Mpa. Some compositions showed proper detail reproduction. Cytotoxicity was not different regardless of the composition, and was similar to those of commercial materials. From the above results, two promising compositions were determined to be used as the basic composition for making a domestic alginate impression material. On this result, beneficial properties of fluoride release, reduced dust production and sufficient antibacterial effect will be added before marketing.

치과용 알지네이트 인상재의 국산화 및 개량에 관한 연구 : Ⅱ. 불소 화합물 첨가 후 특성 변화 Part Ⅱ. The Effects of Fluoride Incorporation on the Properties

이용근,임범순,김철위 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.3

The goal of this study was to develop dental alginate impression materials that is proper for domestic usage conditions. After incorporation of additional techniques into this material to make multifunctional impression materials, this final product can be commercialized. In the first year of this study, although the characteristics were different by the viscosity of sodium alginate, two formula for dental alginate impression materials were determined, which contain sodium alginate, calcium sulfate, diatomaceous earth, borax, magnesium oxide, potassium chloride, sodium acetate, sodium phosphate, zinc fluoride and zinc oxide (WM₃, WM₄, WH₃ WH₄). New technique tried in the second year was the fluoride incorporation to deliver fluoride on the tooth surface during impression procedure. Four methods of fluoride incorporation were tested. Materials were mixed with distilled water, or 100-ppm fluoride solution. 1 or 2% sodium fluoride, or 1% stannous fluoride was incorporated into the powder. The fluoride-containing materials were mixed with distilled water. Fluoride release, compressive strength, elastic modulus, flexibility, recovery form deformation and setting time were determined. As the results, fluoride release was increased after incorporation of fluoride into water or materials, and the released amount was 0.762~14.76ppm. Sodium fluoride or stannous fluoride incorporation resulted in higher fluoride release than the control group (p<0.05). Incorporation of fluoride into alginate impression materials may be efficient in releasing fluoride without having any deleterious effect on the properties of material. Additional study on the method that can enhance the compatibility with gypsum products was performed. All compositions reproduced 50 ㎛ line for 25 ㎜, and immersion of impression into a 2% potassium chloride solution resulted in better surface quality. From the results, these compositions can be used to make commercial dental alginate impression material, however development of additional commercialization procedure is needed. Domestic sodium alginate should be developed to down the price of ingredient materials.

광도 및 광원 차이가 치과용 광중합 콤포짓트레진의 중합깊이에 주는 영향

이용근,임범순,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.2

Inadequately polymerized resin has greater water sorption and solubility, possibly manifested clinically with early color instability and degradation. The purpose of this study was to determine the influence of total light energy (light intensity X irradiation time) of halogen and plasma arc curing units on the polymerization deth of five universal resin composites by measuring the Vickers hardness number (VHN/0.1, 10) at the surface and 0.5, 1.0, 1.5, 2.0, 2.5and 3.0㎜ under the surface. The total light energy for the halogen light curing unit (VIP, Bisco, U.S.A.) was 4,000, 8,000, 16,000 mJ/㎠, and VHN was measured immediately after curing and after 24-hours storage in 37℃ distilled water. Polymerization behavior of plasma arc curing unit (Flipo, Serial No. P03G02221, Lokki, France) was also determined, and the irradiation time was 3 and 9 seconds. From this experiment, the following results were obtained. 1.VHN immediately after light curing was 33.2∼123.3, and showed a great variation depending on the brand of the materials. The curing depth was different depending on the brand of the materials by the variables of light source, total light energy and light intensity. 2.VHN after 24 hours was 36.3∼115.1, and in almost all cases, these values increased in comparison to those immediately after light curing. However, when the total light energy was absolutely insfficient for curing, these values decreased. 3.When the same total light energy was irradiated with different light intensity, the differences in curing depth and VHN were depended on the brand of the materials. 4.In some brand of the materials, the curing depth and VHN were similar regardless of the light source (halogen or plasma arc) when the total light energy was the same.

계면활성제의 분리막에 대한 투과거동

이광래,안순철,김기창 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

The molecular weights of surfactant SDS(M.W. 288) and SLS(M.W. 420) are smaller than the molecular weigh cur-off of cellulose acetate membrane used in this study. However, 20% of SDS and 67% of SLS were rejected by cellulose acetate membrane. The higher rejection rate of SLS than that of SDS is due to the longer hydrophobic chain and greater molecular weight. There was no resistance to permeation rate by membrane fouling. Most of permeation resistance was due to the concentration polarization. Permeation rate was declined with operating time and with increase in concentration of surfactant due to concentration polarization.

레진기질과 생체활성 필러에 따른 콤포짓트레진의 특성

이용근,임범순,김철위 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

In dentistry, since composite resins are used to restore teeth, their chemical and physico-mechanical characteristics should be similar to those of natural tooth. The mineral phase of bone and teeth is mainly hydroxyapatite. Therefore, synthetic hydroxyapatite would seem a good choice as an inorganic filler to he used in dental restoration or bone implant. The purpose of this study was to gain more insight into the possibility of the bioactive filler incorporated composite resin as restorative material, limns; material or pulp capping material through the evaluation of mechanical properties and cytotoxicity. Bioactive fillers such as apatite-wollastonite (AW) glass ceramic, bioglass (BG) and hydroxyapatite (HA) powders, and conventional glass fillers were incorporated into light-curing resin matrices composed of Bis-GMA and TEGDMA (6:4 by wt.), Bis-GMA and HEMA (6:4 by wt.), Bis-GMA, HEMA and TEGDMA (3:4:3 by wt.). and UDMA and TEGDMA (6:4 by wt.). Compressive, diametral tensile and flexural strength of light-cured specimens immersed in 37℃ DW for 24 hours was measured. Cytotoxicity by MTT method was also evaluated. When Bis-GMA and TEGDMA mixture was used as the resin matrix, compressive, diametral tensile and flexural strength of bioactive filler incorporated composite resin was 17.72∼128.22 ㎫. 39.57∼84.46 ㎫ and 21.35∼57.36 ㎫, respectively. When Bis-GMA and HEMA mixture was used as the resin matrix, BG filler incorporated composite resin did not cure, and the highest compressive and diametral tensile strength of bioactive filler incorporated composite resins was 40.24 ㎫ and 35.30 ㎫, respectively. When Bis-GMA, HEMA and TEGDMA mixture was used as the resin matrix, BG filler incorporated composite resin did not cure, and three strength values were highest after incorporating HA filler. When UDMA and TEGDMA mixture was used as the resin matrix, compressive, diametral tensile and flexural strength of bioactive filler incorporated composite resin was 38.61∼137.31 ㎫, 32.59∼110.47 ㎫ and 17.10∼48.70 ㎫, respectively. Generally, cytotoxicity of bioactive filler incorporated composite resin was higher than those of conventional glass filler incorporated resins. From the above result, mechanical properties of bioactive filler incorporated composite resins made of conventional Bis-GMA, UDMA and TEGDMA matrices were moderate; however, those of HEMA-incorporated matrices were low.