CuZn36 합금의 입자 미세화에 미치는 Zr , B , P 첨가의 영향

김정근,이동우 ( Chung Keun Kim,Dong Woo Lee ) 한국주조공학회 1993 한국주조공학회지 Vol.13 No.2

N/A It has been known that the grain refinement of Cu base alloys greatly improved mechanical properties, castability, workability and hot shortness resistance etc. In this study CuZr50, CuP7, CuFe7, CuMg10 binary alloys were added as grain refiners in CuZn36 alloy. The alloys melted in vacuum and controlled in mixed gas conditions and casted at 1050℃. Zr-P-X compound has significantly grain refined but oxygen has been found detrimental to grain refinement. In the case of Zr/B ratio below 4, B acted as grain growth element in this alloy.

Shaw 의 Diabolonian

김정근 ( Chung Keun Kim ) 한국영어영문학회 1963 영어 영문학 Vol.14 No.-

Platelet-derived growth factor가 조골세포의 활성에 미치는 영향

최형호,김정근,임성빈,정진형,Choi, Hyoung-Ho,Kim, Jung-Keun,Lim, Sung-Bin,Chung, Chin-Hyung 대한치주과학회 1999 Journal of Periodontal & Implant Science Vol.29 No.4

The cell activities of bone metabolism is affected by growth factor rather than by hormone. The affects of growth factors on the bone activity were observed using various culture methods. Platelet-derived growth factor(PDGF) is produced from the well differentiated bone cell. It stimulates cell mitosis, synthesizes collagen in bone tissue and plays a role in healing response. The purpose of this study is to evaluate the effects that PDGF has on the activity and the proliferation of osteoblast by measuring the activity of alkaline phosphatase, the growth formation of calcified nodules, and osteocalcin production. In this study, HOS and ROS 17/2.8 osteoblastic cell line was used, along with variable concentrations of PDGF the were measured with osteoblastic proliferation. The cell proliferation of HOS and ROS 17/2.8 cells was stimulated dose- depentdently. Alakline phosphatase activity was significantly decreased by PDGF in osteoblastic cells. A number of small calcified nodules were observed in HOS cell treated with low concentrations(0.1, 0.4 ng/ml) of PDGF-BB and no significant difference from control group was found. High concentrations(10, 50 ng/ml) of PDGF suppressed calcified nodule formation. And osteocalcin production was inhibited with PDGF. These results suggest that PDGF stimulates the osteoblastic proliferation, whereas suppresses the individual cellular functions.

THE RESPONSES OF GINGIVAL AND PERIODONTAL LIGAMENT FIBROBLASTS OT VARIOUS DENTIN CONDITIONED SPECIMENS IN VITRO

임재형,김정근,정진형,Lim, Jae-Hyung,Kim, Jung-Keun,Chung, Chin-Hyung The Korean Academy of Periodontoloy 1995 Journal of Periodontal & Implant Science Vol.25 No.1

치주치료의 궁극적 목표인 치주조직 재생에 대한 관심이 높아지는 가운데 치주조직 재생에 주된 역할을 하는 치주인대세포와 치근면 탈회에 의한 신부착 효과에 관한 많은 연구가 시도되고 있다. 그러나 광범위한 연구에도 불구하고 어떤 치근면 처리가 신부착 형성에 가장 효과적인지는 아직 논란의 대상으로 남아있다. 이에 저자는 결합조직 부착에 의한 재생에 필수적인 치은 및 치주인대 섬유아세포의 부착 및 증식을 tetracycline-HCL(TC)과 citric acid(CA)로 각각 처리된 상아질 표면에서 비교관찰하여 치주조직 재생에의 기여도를 추정하기 위해 본 연구를 시행하였다. 교정치료를 위하여 본원에 내원한 환자의 제일 소구치의 건강한 치은조직을 채취하고, 발치 후 효소처리에 의한 치주인대세포를 얻은 후 각각 세포배양하였다. 상아질 절편은 $3{\times}3{\times}0.2mm^3$로 준비하고 TC과 CA처리군으로 나눈 후 각각 치은 및 치주인대 섬유아세포를 부착시키고 초기부착은 8시간까지, 증식은 7일까지 고나찰하여 다음의 결과를 얻었다. 1. 각 군의 세포 부착은 시간이 지남에 따라 증가되었다. 2. 모든 군에서 7일째 빠른 증식상을 보였다. 3. 초기 부착시 치은과 치주인대 섬유아세포의 반응에는 유의한 차이가 없었다. 4. 반면에 치은과 치주인대 섬유아세포는 증식속도에서 차이를 나타내었으며 치은 섬유아세포가 좀 더 빠른 성장을 보였다. 5. 치근면 탈회에 따라 초기부착과 증식상에서 모두 유의성 있는 증가를 보였다. 6. CA는 초기부착에서, TC는 증식장에서 더욱 효과적으로 작용했다.

Al-Si-Mg (A356) 주조합금의 파괴인성 및 피로균열전파에 미치는 응고속도의 영향

김창주,김정근 ( Chang Joo Kim,Chung Keun Kim ) 한국주조공학회 1991 한국주조공학회지 Vol.11 No.1

N/A Aluminium alloy castings, which can be not only manufactured in larger geometrically complex shapes, but also show good mechanical properties in addition to light weight, have kept their potential use as structures in the field of automotives, industrial machines and aircrafts. The variations of eutectic Si size a great effect on the elongation, impact value, fracture toughness and fatigue crack propagation rate without changes in the tensile strength or yield strength. The cooling curves with the solidification rate between 1.4℃/min and 19.1℃/min were obtained. With the increase of solidification rate, DAS, eutectic Si size and grain size were all decreased, which enhanced the mechanical properties. The tensile strength and yield strength were the most greatly influenced by DAS, and the elongation and impact value by eutectic Si size.

음식물쓰레기의 퇴비화시 하수슬러지의 최적 혼합비율

이영세,최현국,김정근,이용희,정경태,노종수,서명교,Lee Young Sei,Choi Hyun Kuk,Kim Jung Keun,Lee Yong Hee,Chung Kyung Tae,Roh Jong Su,Suh Myung Gyo 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.5

Food waste is becoming by environmental problem nowdays increasing festinately in Korea during past 10 years. Food waste collected from garbage trucks that is offered in S municipal government that food waste mixs enough, and sewage sludge collected in the country. Composting experiment conditions achieved in the mixture ratio rate that food waste and sewage sludge are each 10:90, 30:70, 50:50, 60:40, 70:30 and 90:10 $wt\%$. The fermentation temperature was $18{\sim}22^{\circ}C$ at the beginning, and then it was sharply increased to $44{\sim}66^{\circ}C$ up to 1 day after fermentation, which was maintained for more than 3 days. Then, it was slowly decreased to $18{\sim}25^{\circ}C$ up to 8 days after fermentation, which was maintained all the time. It could be known from examiation of various conditions, including reaction rate, salinity. carbon/nitrogen(C/N) ratio, temperature, organic substance, etc.. Optimum mixture ratio rate of composting using food waste and sewage sludge was 60:40 $wt\%$.

혈소판 농축혈장이 조골세포의 초기부착과 증식 및 활성에 미치는 생물학적 영향

박상일,임성빈,김정근,정진형,Park, Sang-Il,Lim, Sung-Bin,Kim, Jung-Keun,Chung, Chin-Hyung 대한치주과학회 2001 Journal of Periodontal & Implant Science Vol.31 No.3

For reconstruction of the bony defect, various artificial substitutes were developed. Among them, there has been a study of calcium phosphate coated bone substitutes for increasing attachment of osteoblasts in vivo. The purpose of this study was to evaluate the effects of serum and platelet-rich plasma (PRP) on calcium phosphate coated culture plate for the initial attachment, proliferation and activity of osteoblasts. After sampling the blood from white rats and concentrating by centrifugation, the amount of attachment of PDGF-BB and $TGF-{\beta}$ on the calcium phosphate coated culture plate was measured. Cultured HOS and ROS 17/2.8 cell was measured on attachment level and proliferation rate of osteoblasts. Alkaline phosphatase activity of HOS and ROS 17/2.8 cell was measured for studying on the activating rate of osteoblast. 1. Counting the amount of platelets of seperated plasma and PRP, the average number of platelets was 177,003 $cell/{\mu}l$ in plasma, and 1,656,062 $cell/{\mu}l$ in PRP, which was about 9 times as high as in plasma. 2. Amount of PDGF-BB deposited at calcium phosphate coated plate had increased by the total amount of plasma and PRP on the culture plate, whereas $TGF-{\beta}$had been deposited on the plate only when treated by $50{\mu}{\ell}$ of PRP(p<0.01). 3. After plating serum and PRP for 3 hours, we attached with HOS and ROS17/2.8 cell for 1 hour and 4 hours. There were no significant difference of the attachment between serum and control group, whereas there were significantly difference of the attachment between depositioning of PRP and control group. 4. After attaching plasma and PRP for 3 hours, cell number has much increased when HOS and ROS17/2.8 cell had been cultured for 48 hours(p<0.05). 5. After attaching plasma and PRP for 3 hours, concentration of alkaline-phosphatase has increased when HOS and ROS17/2.8 cell had been cultured for 48 hours(p<0.01). These results suggested that PRP affected on initial cell attachment rather than proliferation and activation of osteoblasts at calcium phosphate coated plate.

백두옹 추출물의 치주 병인균에 대한 항균효과

정성화,정진형,임성빈,김정근,소은희,Chung, Sung-Wha,Chung, Chin-Hyung,Lim, Sung-Bin,Kim, Jung-Keun,So, Eun-Hee 대한치주과학회 2000 Journal of Periodontal & Implant Science Vol.30 No.3

Gingivitis and periodontitis are infectious diseases in that microorganisms are the primary extrinsic cause of the diseases. the occurrence of gingivitis has been associated clearly with the presence of microorganisms at the disease site, and the histologic nature of the tissue involved is indicative of an inflammatory response induced by microorganisms. additional evidence for the microbial etiology of periodontal disease is that numerous antimicrobial agents are effective in reducing plaque accumulation and periodontal diseases. the purpose of this article is to analyze the antimicrobial effects of Pulsatilla koreana. Well-dried Pulsatilla koreana purchased from herbs distributor was ground and extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH). we have then applied each solution to the bacteria samples(Bacteroides forsythus, Streptococcus mutans, Streptococcus sanguis, Porphylomonas gingivalis, Actinobacillus actinomycetemcomitans, Eikenella corrodens, Prevotella intermedia, Actinomyces viscosus, Prevotella nigrescens , Rothia dentocariosa, Fusobacterium nucleatum, Pseudomonas aeruginosa, Staphylococcus aureus) collected from several organizations. To conduct susceptibility test(Kirby-Bauer method), plate contained each periodontopathic bacteria is spread extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH) and to measure the minimum inhibition concentration(MIC) of the bacteria against the solutions to ultimately determine antimicrobial effects of the solutions, insert bacteria sample into $20{\mu\ell}/{m\ell}$, $10{\mu\ell}/{m\ell}$, $5{\mu\ell}/{m\ell}$, $2.5{\mu\ell}/{m\ell}$ of each solution and control group(not contained solution) 1. Solution extracted into methanol did not show clear zone against all bacteria samples. Only P.nigrescens, S. mutans and S. sanguis in solution extracted into ethylacetate, S. mutans and S. anguis in solutions extracted into chlorform and Butyl alcohol showed clear zone against all bacteria samples. Solution extracted into Butyl alcohol showed clear zone against 13 types of bacteria, excluding P. gingivalis. 2. In Solution extracted into methanol, the bacteria samples grew in the highest concentrated plate, showing minimal variation from control group. 3. In Solution extracted into Butyl alcohol, S. aureus, P. intermedia, E. corrodens, A. actinomycetemcomitans, B. forsythus, P. gingivalis et al. showed decreased growth in the highest concentrated plate. P. auruginosa, R. dentocariosa, A. viscosus, P. nigrescens, S. mutans et al. showed decreased growth at MIC $20{\mu\ell}/{m\ell}$ and S. sanguis showed decreased growth at MIC $10{\mu\ell}/{m\ell}$. 4. By analyzing the MIC level through considering the results from Kirby-Bauer method, Solution extracted into methanol did not reveal any antimicrobial effects and Solution extracted into Butyl alcohol showed the highest antimicrobial effects In conclusion, it can be used the extracts of Pulsatilla koreana as wide spectrum antimicrobial agent.

柏子仁과 側柏葉의 성분인 myricetin이 멜라닌 생성에 미치는 영향

송화영(Hwa Young Song),김정근(Jeong Keun Kim),홍석훈(Seok Hoon Hong),황충연(Chung Yeon Hwang),김남권(Nam Kwen Kim) 한의병리학회 2004 동의생리병리학회지 Vol.18 No.3

백두옹 추출물의 치주조직 세포에 활성도 및 항염 효과에 관한 연구

정진광,정진형,임성빈,김정근,소은희,Jung, Jin-Gwang,Chung, Chin-Hyung,Lim, Sung-Bin,Kim, Jung-Keun,So, Eun-Hee 대한치주과학회 2001 Journal of Periodontal & Implant Science Vol.31 No.1

This study was performed to define the cytotoxicity and the anti-inflammatory action of Pulsatilla koreana extracts. To analyze cytotoxic effects, gingival and periodontal ligament fibroblasts were used, and anti-inflammatory actions related to reduction of $IL-1{\beta}$ and $PGE_2$ production were performed in vitro, for the suggestion of efficacy and safety on periodontal therapeutic use of Pulsatilla koreana extracts. We extracted ethylacetate and butylalcohol from well-dried and ground Pulsatilla koreana throughout multiple processing, then used different concentration solution(0.1 %, 0.2 %, 0.4 %, 0.01 %, 0.02 %, 0.04 %, 1 %, 2 %) of ethylacetate and butylalcohol extracts to examine eytotoxic effects and anti-inflammatory actions Cytotoxic effects were examined by ELISA reader using MTT(Methyl Thiazol-2-YL-2, 5-diphenyl Tetrazolium bromide)solution following culture of human gingival and periodontal ligament fibroblasts. Synthesis of $IL-1{\beta}$was examined by $IL-1{\beta}$ enzyme-immunoassay(EIA)system after separation and culture of monocyte, and $PGE_2$ was examined by $PGE_2EIA$ system after culture of gingival fibroblasts. The results were as follows: 1. In the MTT test of gingival fibroblasts, the change of optical density was decreased significantly at 2 % of butylalcohol extracts and 0.04 %, 0.1 %, 0.2 %, 0.4 %, 1 %, 2 % of ethylacetate extracts.(p<0.05) 2. In the MTT test of periodontal ligament cells, the change of optical density were not differ significantly. but butylalcohol and ethylacetate extracts except from butylalcohol 0.01 % showed high cell cytotoxity. 3. Both ethylacetate and butylalcohol extracts from Pulsatilla koreana inhibited the synthesis of $IL-1{\beta}$and inhibition effect of ethylacetate extracts were higher than butylalcohol extracts. 4. Both ethylacetate and butylalcohol extracts from Pulsatilla koreana inhibited the synthesis of $PGE_2$, and ethylacetate extracts were higher than butylalcohol extracts. In conclusion, ethylacetate and butylalcohol extracts from Pulsatilla koreana showed little cell cytotoxity for gingival and periodontal ligament fibroblasts, and the inhibition of $IL-1{\beta}$ and $PGE_2$ sysnthesis, therefore it is considered that these extracts can be developed as the therapeutics of the periodontal disease.