SD Rats를 이용 1-hexene의 흡입독성 연구

김현영,임철홍,정용현,이권섭,이성배,이준연,한정희,전윤석,이용묵 한국환경독성학회 2001 환경독성보건학회지 Vol.16 No.4

The purpose of this study was to investigate the acute (4 hours) and repeated-dose (6 hours a day, 5 days a week, 4 weeks) toxic effects of I -hexene on Sprague- Dawley (SD) rats which were treated by inhalation. The results were as follows; I. The median lethal concentration (LC_(50)) was estimated 52,694 ppm (confidence limit 95%; 49,494~55,447 ppm) in acute inhalation. Abnormal clinical signs related to the l-Hexene were not observed with the acute inhalation dose. Gross findings of necropsy revealed on evidence of specific toxicity related to the 1-hexene, II. By repeated inhalation exposure the body weight of male were more or less reduced by the dose of 2,500 ppm and 5,000 ppm compared with control group. However there were no significant variation hematology and blood biochemistry for the exposed rats compared with the control rats. Abnormal clinical signs and gross findings of necropsy related to the 1-hexene were not shown. In conclusion when we exposed I-hexene to SD rats for 4 weeks, 5 days per week, 6 hours per day, the Lowest observed effect level (LOEL) was over 2,500 ppm and Non observed effect level (NOEL) was below 500 ppm.

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.

위에 발생한 유암종 (Carcinoid Tumor) : 1예 보고

김남재,김진희,이경태,서광식,정현용,이승민,김석현,이병석,이헌영 대한소화기내시경학회 1999 Clinical Endoscopy Vol.19 No.3

A carcinoid tumor of the stomach is uncommon, has no clinical symptoms, and is regarded as a benign. It is also incidentally found in most cases. 48-year-old woman with gastric carcinoid tumor was admitted. She had suffered from a anorexia and a dry mouth for 4-months. A gastroscopy revealed a polypoid mass on the greater curvature of the mid-body of the stomach which was subsequently thought to be an adenocarcinoma. An endoscopic mucosectomy revealed however, that it was a carcinoid tumor. A case of carcinoid tumor of the stomach is here by presented with a brief literature review.

올레산의 비율에 따른 아데노신의 경피 투과의 영향

남현빈,정세진,구민석,오예진,김용민,이훈희,윤수정,임정균 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

In addition to the development of functional cosmetics, technology to increase percutaneous absorption rate when applied to the skin is an important task. In this experiment, oleic acid was used as a skin absorption promoter, and its effect on transdermal permeability of adenosine was studied and analyzed using a skin-like membrane. As a result of the experiment, it was investigated that the permeability coefficient and concentration of adenosine are proportional to the content of oleic acid. This indicates that a high proportion of oleic acid is effective as a skin absorption promoter.

열린 교육과 미술 교육 : 그 상관성에 관하여

이쌍재,이현석 晋州敎育大學校 初等敎育硏究所 1997 初等敎育硏究 Vol.7 No.-

綠豆品種集團에 있어서 量的形質에 대한 遺傳分析

李相昊,高美錫,金碩鉉 慶尙大學校 1985 論文集 Vol.24 No.2

多收性 綠豆品種 育成을 위한 基礎資料를 얻기 위하여 21個 品種을 材料로 各 形質에 대한 遺傳力 및 遺傳相關等을 推定한 바, 그 結果는 다음과 같다. 1. 遺傳力은 100 粒重 및 傳長, 그리고 開花日數는 높았으나 成熟日數와 粒重은 낮았고 其他 形質들은 中間程度였다. 2. 形質相互間의 相關關係에서 開花日數와 莖長은 莖長과 100 粒重을 제외한 全 形質間과 正외 相關이 있었고, 100 粒重은 成熟日數와 萊長과는 표의 相關으로 其他 全 形質과는 負의 相關을 보였다. 3. 收量, 즉 粒重은 開花日數, 莖長, 莖直徑, 分枝數 및 樣當萊數等과 高度의 正의 相關을 보여 이 形質 들이 綠豆의 收量을 增大시킬 것으로 推定되었다. This experiment was conducted to estimate genetic parameters, such as heritabilities, genotypic and phenotypic correlation coefficients of some agronomic characters in mungbean. Twenty one varieties were planted in a randomized block design with three replications and 10 quantitative characters, i. e., days to flowering, days from flowering to maturity, days to maturity, plant height, stem diameter, branch numbers per plant, pod length, pod numbers per plant, 100 grain weight and grain weight per plot were observed. The results obtained are summarized as follows: 1. The highest heritability value was found for 100 grain weight, and those of days lo flowering and pod length were higher than other characters. But the lower values were found with days from flowering t9 maturity and grain weight per plot. 2. The genotypic correlations among all pairs were slightly higher than the corresponding phenotypic correlations. 3. The phenotypic and genotypic correlations between grain weight and other characters indicated that high grain yield was genetically correlated with days to flowering, plant height, stem diameter, branch numbers per plant and pod numbers per plant. Therefore, these characters were suggested that selection for high yield may be more effective than the other agronomic characters.

전기도금을 이용한 스테인레스 스틸 각형 선재의 굵기 증가 후 물성 변화

이정석,이기헌,황현식 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.2

본 연구는 전기도금을 이용하여 각형 선재의 굵기를 증가시킨 후 기존의 선재와 물성을 비교함으로서 이의 임상적 적용 가능성을 알아보고자 시행되었다. 한 변의 길이가 0.016 인치인 정사각형 스테인레스 스틸 교정용 선재에 니켈 전기도금을 시행하여 굵기를 0.01 인치 증가시켜 한 변의 길이가 0.017 인치인 정사각형 선재로 만들었고 도금층의 밀착성을 증진시키기 위해 400℃의 전기로 에서 10분간 열처리를 시행하였다. 시편의 물성변화를 알아보기 위하여 전기도금을 이용하여 제작된 15개의 시편을 실험군(016P군)으로, 기존의 0.016인치(016), 0.017 인치(017군) 스테인레스 스틸 교정용 선재를 대조군으로 설정한 후 3점 굴곡 시험과 비틀림 시험을 시행하여 다음과 같은 결과를 얻었다. 1. 3점 굴곡 시험 결과 016P군에 비해 강성과 항복강도, 국한강도 모두 증가하는 경향을 보였으며, 강성과 극한강도는 통계적으로 유의한 차이가 있었다(p<0.05). 2. 3점 굴곡 시험 결과016P군이 017보다 강성과 항복강도, 극한강도 모두 낮은 경향을 보였으며, 강성은 통계적으로 유의한 차이가 있었다(p<0.05). 3. 비틀림 시험 결과 016P군이 016군에 비해 비틀림 모멘트, 최대 비틀림 모멘트 모두 높았으며, 통계적으로 유의한 차이가 있었다(p<0.05). 4. 비틀림 시험 결과 016P군이 017군에 비해 비틀림 강성과 항복 비틀림 모멘트, 최대 비틀림 모멘트 모두 낮은 경향을 보였으며, 이 중 항복 비틀림 모멘트와 최대 비틀림 모멘트에서 통계적으로 유의한 차이가 있었다(p<0.05). 이상의 결과를 요약해 보면 각형 선재에 도금을 시행하여 굵기를 증가시키고 물성이 증가될 수 있음을 알았다. 비록 도금을 시행한 016P군이 기존의 017군보다 강성이 낮았으나 이는 반대로 016P군이 017군보다 탄성이 높음을 나타내며 토크조절이 부족한 경우 브라켓 슬롯에 쉽게 삽입되어 교정력을 발휘할 것으로 기대된다. The purpose of this study was to evaluate clinical applications of electroplating method through investigation of the physical properties of orthodontic rectangular wires according to varying their cross section. For the study, it was accomplished to electroplate the 0.016-inched orthodontic rectangular stainless steel wire. The cross section of stainless steel orthodontic rectangular wire increased from 0.016 x 0.016 inch to 0.017 x 0.017 inch by electroplating. The wire was heat treated to improve an adhesion between the wire and electroplated metal. A three=point bending test and torsion test were conducted in order to compare physical properties among three wire groups; 0.016 X 0.016 wires (group 016), electroplated 0.016 x 0.016 wires (group 016P) and 0.017 x 0.017 wires (group 017). Through the investigation of each wire group, following results were obtained. 1. At three-point bending test, the group 016P showed higher tendency in the degree of stiffness, yield strength and ultimate tensile strength than the group 016. Stiffness and ultimate tensile strength showed statistically significant differences between two groups at three-point bending test (p<0.05). 2. Stiffness, yield strength, and ultimate tensile strength of the group 016P showed lower tendency than those of the group 017. Stiffness showed statistically significant differenced between two groups at three-point bending test (p<0.05). 3. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed higher tendency than those of the group 016. All measurements showed statistically significant differences between two groups after torsion test (p<0.05). 4. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed lower tendency than those of the group 017. Yield torsional moment, and ultimate torsional moment showed statistically significant differences between two groups after torsion test(p<0.05)

전기도금을 이용한 스테인레스스틸 각형 선재의 굵기 증가 후 물성 변화

이정석,황현식,최광철,문재동 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.1

The purpose of this study was to evaluate clinical applications of electroplating method through investigation of the physical properties of orthodontic rectangular wires according to varying their cross section. For the study, it was accomplished to electroplate the 0.016-inched orthodontic rectangular stainless steel wire. The cross section of stainless steel orthodontic rectangular wire increased from 0.016 X 0.016 inch to 0.017 X 0.017 inch by electroplating. The wire was heat treated to improve an adhesion between the wire and electroplated metal. A three-point bending test and torsion test were conduced in order to compare physical properties among three wire groups; 0.016 X 0.016 wires(group 016P) and 0.017 X 0.017 wires(group 017). Through the investigations of each wire group, following results were obtained. 1. At three-point bending test, the group 016P showed higher tendency in the degree of stiffness, yield strength and ultimate tensile strength than the group 016. Stiffness and ultimate tensile strength showed statistically significant differences between two groups at three-point bending test(p<0.05). 2. Stiffness, yield strength, and ultimate tensile strength of the group 016P showed lower tendency than those of the group 017. Stiffness showed statistically significant differences between two groups at three-point bending test(p<0.05). 3. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed higher tendency than those of the group 016. All measurements showed statistically significant differences between two groups after torsion test(p<0.05). 4. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed lower tendency than those of the group 017. Yield torsional moment, and ultimate torsional moment showed statistically significant differences between two groups after torsion test(p<0.05). Xylitol is a 5-carbons carbohydrate, which can be replaced with sucrose for preventing caries. The replication of Streptococcus mutans and its formation of artificial plaque were studied in the media containing xylitol. The combined effect of xylitol and other carbohydrates on Streptococcus mutans was also studied. The replication of Streptococcus mutans was inhibited according to the increased concentration of xylitol. Streptococcus mutans replicated at the initial stage of incubation in the media contaning glucose, fructose or lactose, while replication from the beginning of incubation in the media containing fructose as combining with xylitol. The formation of artificial plaque by Streptococcus mutans was significantly reduced in the media containing with xylitol and fructose. These results indicated that the replication of Streptococcus mutans was inhibited according to the increased concentration of xylitol, and the formation of artificial plaque by Streptococcus mutans was significantly inhibited in the media containing xylitol and fructose.

폴리카보네이트 브라켓 부착 시 결합강도 증진을 위한 표면처리 효과

김석필,김년경,이현정,황현식 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.5

본 연구는 폴리카보네이트 브라켓 부착 시 표면처리가 결합강도를 증진시키는지 알아보고자 시행되었다. 소의 하악 중절치를 포매하여 만든 100개의 시편에 광중합형 레진 접착제를 이용하여 폴리카보네이트 브라켓(Alice, 광명 데이콤, 대한민국)을 부착하였다. 대조군의 경우, 표면처리 없이 부착한 반면, 실험군의 경우 샌드블라스팅 처리한 경우, plastic conditioner 처리하여 부착한 경우, 그리고 샌드블라스팅과 함께 plastic conditioner 처리한 경우로 구분하여 접착하였다. 만능시험기를 이용하여 전단결합강도를 측정하고 파절양상을 비교 분석한 결과, plastic conditioner나 샌드블라스팅으로 표면처리를 시행한 경우 표면처리를 시행하지 않은 경우에 비해 높은 결합강도를 보였다 (p<0.001). 샌드블라스팅과 Plastic conditioner를 모두 처리한 경우는 샌드블라스팅만이나 plastic conditioner만 처리한 경우보다 높은 결합강도를 보였으며, 특히 샌드블라스팅만 처리한 경우에 비해서는 통계적 유의차를 보였다 (p<0.05). 이상의 연구결과는 폴리카보네이트 브라켓 부착 시 결합강도 증진을 위해서 베이스의 표면처리가 필요하며 샌드블라스팅 후 plastic conditioner 도포가 가장 효과적임을 보여주었다. Objective: The purpose of this study was to evaluate whether the bond strength of polycarbonate brackets can be increased through surface treatment. Methods: One hundred polycarbonate brackets (Alice) were bonded to bovine incisors with light-cured adhesive. The bracket bases were treated with one of three methods; sandblasting, plastic conditioner application, and combined treatment with sandblasting and plastic conditioner. The brackets without any surface treatment served as the control. The shear bond strength was tested with a universal testing machine, and failure pattern was assessed with the adhesive remnant index. Results: The shear bond strength in all experimental groups was higher than that of the control group (p<0.001). The group treated with plastic conditioner after sandblasting showed statistically higher shear bond strength than the sandblasting only group (p<0.05). The group treated with plastic conditioner after sandblasting showed higher shear bond strength than plastic conditioner only group, but the difference was not statistically significant. Conclusion: The above results suggest that the surface treatments of polycarbonate bracket is mandatory to improve bond strength, and the most effective method is an application of plastic conditioner after sandblasting.

분만 전·후 사료급여 형태가 젖소의 생산성에 미치는 영향

기광석,김현섭,이왕식,이현준,김상범,정하연,은정식,김용국 충남대학교 농업과학연구소 2007 농업과학연구 Vol.34 No.2

This experiment was carried out to protect drops of feed intake should be plural prepartum and postpartum to reduce metabolic diseases after calving to know how feeding systems, which is divided as a low quility, a high quility and total mixed rations(TMR), affects on postpartum productivity of Holistein cows. Three diets (low or high quality forage separately fed with concentrate and TMR containing high quality roughage) were fed to 21 cows from 3 weeks prepartum to 8 weeks postpartum to examine their effects on the productivity of cows. DM intakes was noticed significantly higher with TMR (17.11kg/day) than low- quality (13.48 kg/day) and high-quality forage (13.10kg/day). TDN and CP intakes were also higher with TMR compared to other experimental diets. Mean daily milk yield was non-significant among the cows fed different diets. Blood non-esterified fatty acids(NEFA) content was higher in cows fed low-quality or high-quality forage separately with concentrate compared with those fed TMR. The results concluded that TMR feeding to transitional cows is better than feeding the low or high quality forage separately for their health and productivity. 본 시험은 분만 전 3주부터 분만 후 3주까지 전환기라고 지칭되는 시기의 젖소들에 대한 대사적 변화를 최소화하기 위한 방법으로 사료 섭취량 저하를 방지하고 분만 후 대사성 질병의 발생을 줄이기 위한 목적으로 수행되어졌다. 대사성 질병에 관여하는 주요 요인으로는 건물섭취량, 혈중 glucose 함량, NEFA 함량, 반추위 환경, 면역 등인데, 분만 전·후 Holstein 젖소에 사료급여 형태를 조·농분리(저질 조사료와 양질 조사료 급여구) 및 TMR로 다르게 하였을 때 사료섭취량 변화와 혈중 NEFA 및 glucose 함량 변화를 측정하고 분만 후 젖소의 생산성에 미치는 영향을 구명하기 위하여 수행하였다. 처리별 사료건물 섭취량은 저질 조사료 조·농 분리, 양질조사료 조·농 분리, TMR 급여구에서 각각 13.48, 13.10, 17.11kg으로 TMR 급여구에서 유의성 있게 높았으며(P〈0.05), TDN 섭취량은 처리구별 각각 7.35, 7.19, 5.66kg으로 처리간에 차이가 없었다(P〉0.05). 신체충실지수(BCS)는 저질조사료구에서는 3.03이였으며, 양질 조사료구와 TMR 급여구에서는 각각 3.19, 3.16이었다. 분만후 1주부터 5주까지 측정한 평균 산유량은 저질조사료 조·농 분리, 양질 조사료 조·농 분리, TMR 급여구에서 각각 34.1, 35.1, 35.6kg 였으며, 분만 후 4∼5주에 최고 비유기에 달했다. 처리별 평균 유지율은 저질 조사료 조·농 분리, 양질 조사료 조·농 분리, TMR 급여구에서 각각 3.74, 3.68, 3.95%였다. 혈청내 NEFA 함량은 저질 조사료 조·농 분리, 양질 조사료 조·농 분리, TMR 급여구에서 각각 744.4, 381.8,266.7μEq/L로 처리간에 큰 차이를 보여 양질 조사료 급여와 TMR 급여시 혈중 NEFA 함량이 저질 조사료 급여에 이해 유의성 있게 낮았다(P〈0.05). 혈청내 glucose함량은 저질조사료 및 양질 조사료 조·농 분리, TMR 급여구에서 각각 39.3, 56.3, 62.4mg/dl로 양질 조사료 급여와 TMR 급여시 혈중 glucose 함량이 저질 조사료급여에 비해 유의성 있게 높았다(P〈0.05). 이상의 결과들을 종합해 볼 때, 분만 전 3주부터 분만 후 3주까지의 전환기 동안 사료섭취량 증가와 대사성 질병의 지표로서 혈중 NEFA 및glucose 함량 변화를 살펴 본 결과 분만 전 3주부터는 양질의 조사료나 TMR 형태로 급여하는 것이 사료섭취량 증가와 대사성 질병의 발생을 감소시킬 수 있을 것으로 사료되었다.