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.

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 인산칼슘계 충전 및 재생재료 개발(Ⅰ)

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

Because calcium phosphate materials including hydroxyapatite are bioactive and exhibit good biocompatibility, these compositions are actively tried as the hard substituting materials. At the beginning of the development of the calcium phosphate materials, these materials were used as sintered ceramics. After then, plastic calcium phosphate cements were developed to make the shape of the material directly at the site of application. Reports on the dental calcium phosphate materials can be assorted into some categories; development of root apex sealing material or canal sealer, development of pulp capping material or cavity liner, or the reinforcement through addition of resin materials. Studies on the biocompatibility and drug delivery system may be other categories. The final purpose of this study is the development of dentine substituting materials based on calcium phosphate, which is highly biocompatible with the tooth pulp and additionally can stimulate or accelerate the dentine formation. In this preliminary study, PMVE-Ma (polymethy1 viny1 ether-maleic anhydride), HPMC (hydroxypropy1 methy1 cellulose), acrylic resin and acrylic-maleic copolymer was added into the PBS (phosphate buffered solution) to optimize the mechanical and chemical properties of calcium phosphate cement. From this study, AC-1 (4:1 mixture of cement powder and resin powder mixed chemical cure acrylic resin solution) showed the highest diametral tensile strength after storage in 100 % relative humidity for 24 hours, and AM-3, AM-2 (4:1 mixture of cement powder and resin powder mixed with 40 or 30 % acrylic-maleic copolymer) followed. The ranking of compressive strength from the highest in the same condition was AC-1, AM-2 and HP-4 (cement powder mixed with 15 % PMVE-Ma in DW). HP-4 showed the highest diametral tensile strength after storage in normal saline for 24 hours, and AC-1 and AC-2 (9:1 mixture of cement powder and resin powder mixed chemical cure acrylic resin solution) followed. The ranking of compressive strength from the highest in this condition was AC-1, HP-4 and HP-6 (cement powder mixed with the 1:1 mixture of 2 % HPMC in DW and 15 % PMVE in DW). From the point of the mechanical properties, AC-1, HP-4, AM-3 and AM-2 seemed proper for dentine filling material. Addition of resin materials did not influence on the speed and ratio of hydroxyapatite formation. From this study, appropriate compositions based on calcium phosphate for dentine filling materials can be found.

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.

광원 및 광조사 방법에 따른 심미충전재의 중합수축

이용근,윤태호,임범순,김철위 대한치과기재학회 2000 대한치과재료학회지 Vol.27 No.4

The polymerization shrinkage of dental esthetic filling materials of five kinds of resin composite and three kinds of compomer was measured with a thermal dilatometer (Thermal Dilatometer, DIL 402C, TASC 414/3A Controller, Netzche, Germany) during polymerization with a halogen lamp curing unit (VIP, Bisco, U.S.A.) or a plasma arc curing unit (Flipo, Serial No. P03G02221, Lokki, France). The irradiation time of the halogen lamp was 40, 80 and 120 s with the intensity of 400 ㎽/㎠, and that of the plasma arc was 9 s. The pulse-cure mode with a halogen lamp was 5 s pre-polymerization at 200 ㎽/㎠, 3 minutes wait and then 120 s irradiation at 400 ㎽/㎠. From this experiment, the following results were obtained : 1.Depending on the irradiation source and mode, the amount of polymerization shrinkage after 14 minutes from the start of irradiation was significantly different in some materials. However, there was no significant difference in most of materials (p>0.05). 2.Most of the polymerization shrinkage occurred within two minutes from the start of irradiation except for pulse-cure. 3.In all the materials studied, the amount of polymerization shrinkage after 14 minutes from the start of irradiation was not different between the results from 120 seconds irradiation with the halogen lamp and these from pulse-cure (p> 0.05), and the amounts of shrinkage from a plasma arc was generally lower than those from other curing modes. 4.The amount of polymerization shrinkage after 14 minutes from the start of irradiation was not different between the results from 120 seconds irradiation with a halogen lamp and those from plasma arc (p>0.05) in all the eight materials studied.

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.

치과용 저채도, 고투명도 콤포짓트레진의 색상특성에 관한 연구

이용근,임범순,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.1

최근 개발된 저채도 및 고투명도 색상의 콤포짓트레진을 대상으로 미중합 상태, 중합후 및 열순환 후의 색상을 측정하여 중합 과정과 열순환 후의 변색도를 기존 색상의 콤포짓트레진과 비교하였고, Vita 색조가이드 및 Bioform 색조가이드의 색상과의 관계를 보았다. 또한 색측정 방법 및 색상을 측정할 때 사용하는 표준광원의 종류에 따른 색상의 차이를 분석하였다. 2종의 콤포짓트레진을 대상으로 분광광도계(CM-3500d, Minolta, Japan) 로 정반사광 제거방식 (SCE) 및 정반사광 포함방식 (SCI) 등 두 종의 측정방법과 색상측정용 광원으로 표준광원 C, A 및 D65 를 이용하여 색상을 측정하였다. 시편의 열순환은 5~55 ℃에서 3,000 회 실시하였다. 색조가이드의 색상은 색조 탭의 순면을 2,400 번까지 사포로 연마하여 분광광도계의 측정광의 직경인 3mm 이상의 평평한 면을 만든 후 측정한 바, 다음과 같은 결과를 얻었다. 1.표준광원의 차이에 의한 색차(ΔE*)는 저채도 색상이 기존 색상의 콤포짓트레진보다 중합전, 중합후 및 열순환 후 조건에서 모두 크게 나타났으며, 표준광원 A는 C와 D65 와 차이가 큰 것으로 나타났다. 또한 SCE 방식과 SCI 방식으로 측정한 색차는 유사하였다. 2.중합전과 중합후의 색차 및 열순환 후의 변색도는 저채도 색상군의 경우가 표준광원의 종류와 무관하게 기존 색상군의 콤포짓트레진보다 유의하게 높았으며 (p〈0.05), SCE 방식으로 측정한 색차는 SCI 방식으로 측정한 색차보다 높았다. 3.색조가이드의 색좌표중 CIE L*과 CIE b* 는 표준광원 A로 측정한 값은 다른 광원을 사용하였을 때보다 높았고, CIE a* 는 표준광원 A와 D65로 측정한 값이 C로 측정한 경우보다 높았다. 4.Vita 색조가이드의 색상계열(A, B, C, D)은 SCE 방식으로 측정한 L* 값 및 a* 값과 음의 상관관계가 있었으며 다중회귀계수는 0.87이었다. 또한 Chromascop 색조가이드의 색상계열 (100, 200 등) 은 SCI 방식으로 측정한 L* 값과 음의 상관관계를 보였다. 5.저채도 및 고투명도 색상을 포함하는 체계적인 색조가이드의 개발이 필요하다.

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.

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.