• KSBB Journal
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• v.7 no.2
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• pp.92-95
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• 1992

A model for the role of serum was proposed to develop a low serum medium for the large scale cu1ture of mammalian cell. The strategy of medium development adopted in this study facilitated the understanding of the role being carried out by the serum in the culture of hybridoma KAl12 cell line. In this model, the serum components were divided into two main groups : the first group encompasses the nutrient factors that determine the maximum cell density and the second group includes the growth factors that regulate the cell growth rate, The model prediction was compared with the experimental results. The model enabled us to find out several useful aspects of medium composition for cell growth. 1) One particular component in the basal medium became limiting factor when serum concentration level was more than 7%. 2) The growth regulating factors and nutrient factors limited the cell growth at 3% and 5% serum concentration levels respectively.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.449-456
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• 2018

The purpose of this study was to identify the effects of bicycling exercise by analyzing the changes of inflammation-related factors and growth hormone with obese middle-aged women for 8 weeks to identify the effects of bicycle exercise. In this study, 15 middle aged obese women were divided into exercise group and control group. Changes in inflammation-related factors and growth hormone were analyzed as a measurement variable were analyzed by employing two-way ANOVA with repeated measures. This study finds that $TNF-{\alpha}$ and IL-6 were significantly decreased in the exercise group and increased in the control group. Growth hormone was increased in the exercise group but not in the control group. The results of this study suggest that bicycling exercise is an exercise program to prevent cardiovascular and chronic diseases of obese middle-aged women.

• Journal of Periodontal and Implant Science
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• v.34 no.4
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• pp.781-790
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• 2004

골아세포의 생물학적 기능을 증진시키기 위해 키토산의 표면개질에 대하여 연구하였다. 생체적합성 천연고분자인 키토산은 1차 아미노기를 소유하고 있으므로 적정한 공유결합제를 사용하여 세포성장인자와 같은 생리활성을 지닌 단백질을 키토산의 표면에 고정시킬 수 있다. 본 연구에서는 키토산을 필름형태로 제조하여 세포성장인자 중 형질전환성장인자를 고정하고 골아세포의 부착, 성장 및 분화를 증가시키고자 하였다. 형태전환성장인자의 고정화 효율은 단순한 흡착방법에 비해 높았으며, 표면에 형성된 공유결합은 매우 안정하였다. 골아세포를 배양하여 초기세포부착능에 대한 영향을 연구한 결과, 배양 후 4시간, 1일째, 형질전환성장인자를 고정한 키토산 표면에서 고정하지 않은 키토산의 표면에 비해 더 많은 수의 골아세포가 부착되었고, 더 많이 신장된 부착형태를 보였다. 세포활성정도와 배양 후 4주일째의 칼슘축적량을 측정한 결과, 형질전환성장인자를 고정한 키토산 표면에서 고정하지 않은 키토산의 표면에 비해 더 높았다. 위의 결과는 키토산 표면에 형태전환성장인자의 고정이 성공적으로 이루어졌으며, 또한 실제로 활성이 있는 것이 증명되었다. 위의 연구 결과에서 형질전환성장인자로 고정된 키토산은 골아세포의 초기 부착 및 분화를 촉진시켰음을 알 수 있었던 바 성장인자의 표면고정은 임플란트 및 조직공학용 지지체에도 적용하여 생체적합성과 세포기능을 증진시키는데 이용할 수 있음을 알 수 있었다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.124-129
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• 2001

점 용접부는 응력상태가 복잡하고, 피로균열은 판 두께, 너겟 직경, 용접 타점수, 부하 방식 등의 역학적인 인자와 재질, 화학성분, 표면 상태 등의 재료적인 인자, 그리고 용접전류, 가압력, 통전 시간등의 용접적인 인자의 영향을 동시에 받으며 3차원적으로 성장하므로 균열 성장 모드는 항상 혼합보드이고 균열이 박판 내면에서 발생. 성장하므로 검출이 곤란하여 균열 성장의 해석 및 예측이 어렵다/sup 1)/. 따라서 비접촉, 실시간, Whole-field, 레이저 파장 단위까지 측정이 가능하여 기존의 방법들의 문제점을 극복할 수 있고, 반도체와 같은 소형의 제품뿐만 아니라 기존에 측정하지 못했던 초고온, 대형 구조물의 변형도 정확하게 측정을 할 수 있는 ESPI법을 이용하여 일반가전 제품, 자동차 건축용에 많이 사용되고 있는 아연도금강판(SGCC)을 선택하여 단일 용접조건으로 점용접의 피치를 변화시켜 시험편을 제작하고 면외변위를 다각도로 측정하여 그 가능성을 검증하고자 한다.(중략)

• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.523-527
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• 2008

Purpose : Several cytokines play important roles in the inflammatory process of Henoch-$Sch\ddot{o}lein$ Purpura (HSP). It is likely that transforming growth $factor-{\beta}$ ($TGF-{\beta}$) is involved in the pathogenesis of HSP. The purpose of this study is to investigate whether $TGF-{\beta}$ promoter polymorphism is associated with the renal involvement of childhood HSP. Methods : Thirty-four patients younger than 15 years, who had been diagnosed with HSP, as well as 27 controls, were examined. Patients and controls were genotyped for $TGF-{\beta}$ C-509T by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results : The T allelic frequencies in patients and controls showed no difference (45% vs. 48.8%). No allele or genotype differences between the group of HSP group and control group were observed. The frequencies of $TGF-{\beta}$ 509 genotypes TT, TC, and CC were no different between patients and controls (26% vs. 22%). The TT genotype of polymorphism of the $TGF-{\beta}$ C-509T gene had no relation to the susceptibility of children to HSP and renal involvement in HSP. Conclusion : $TGF-{\beta}$ T allele may not be related to the susceptibility of children to HSP. The TT genotype of polymorphism of the $TGF-{\beta}$ C 509T gene does not appear to have an influence on renal involvement in childhood HSP.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.395-402
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• 2005

In considering the healing process of injured periodontal tissue, healing rate would be influenced by the cellular activity of periodontal fibroblasts(PDLFs). In addition, the reattachment among PDLFs should be induced for healing process. The purpose of this study was to evaluate the effects of epidermal growth factor(EGF) on the proliferation and attachment of PDLFs and to verify the efficacy of EGF as a storage media or a pre-replantation conditioner of traumatically avulsed tooth. Human recombinant epidermal growth factor(hrEGF) and human periodontal fibroblasts from first premolar were prepared. At first, MTT assay was done to evaluate the toxic effect on human periodontal fibroblast and the maximum cellular growth of EGF. Cellular proliferation rate was then compared between control group and 10ng/ml EGF added group. Also, western blot was done to evaluate the expression of fibronectin in both groups. The results were as follows: 1. From MTT assay, EGF showed no toxic effect on PDL fibroblasts. The highest proliferation was shown at 10ng/ml EGF. 2. In 10ng/ml EGF added group, the degree of proliferation of PDLFs was significantly higher than that in control group. 3. Fibronectin expression of EGF added group was also significantly higher than that of control group. From this study we could conclude that EGF enhanced the regeneration rate of periodontal fibroblast, which could be used as a pretreatment agent or a storage media for traumatically avulsed teeth.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.687-694
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• 2003

Purpose : Regeneration and repair after ischemic renal injury appears to be modulated by circulating or locally produced growth factors. This study examined the changes of serum insulin like growth factor(IGF-I) and renal expression of IGF-I and II, vascular endothelial growth factor(VEGF), transforming growth $factor-{\beta}$($TGF-{\beta}$), and connective tissue growth factor(CTGF) during the active regeneration period after acute ischemic injury. Methods : Sera and kidney tissue samples(whole kidney, cortex, outer medullae and inner medullae) were obtained before and after one, three, five and seven days of 40 minutes bilateral renal pedicle clamping. Acute renal failure was assessed by measuring the concentration of serum creatinine. Serum IGF-I level was measured by radioimmunoassay. The mRNA expression in kidney was measured by RT-PCR. The distribution of IGF-I and CTGF was detected by immunohistochemistry. Resuts : Serum IGF-I concentration after one day following acute ischemic renal injury was significantly decreased compared to preischemic value. The mRNA levels of IGF-I, IGF-II, $TGF-{\beta}1$ and VEGF in whole kidney were temporally decreased on day one of ischemic injury. IGF-I and IGF-II expressions in outer medullae were significantly decreased on day one after ischemic injury. $TGF-{\beta}1$, CTGF and VEGF expressions were markedly decreased in medullae after one day of ischemic injury compared to other kidney sections. IGF-I was markedly decreased in cortical tubules on day one of uremic rat. CTGF was markedly increased on tubule within three days of ischemic injury. Conclusion : These findings suggest that IGFs, $TGF-{\beta}1$ and CTGF may involve in the pathogenesis or the recovery from acute ischemic renal injury.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.203-209
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• 2016

Purpose: Stimulating the proliferation and migration of periodontal ligament cells (PDLCs) has become the main goal of periodontal regeneration. To accomplish this goal, regeneration procedures have been developed, but results have not been predictable. Recently, tissue engineering using enamel matrix derivatives (EMDs) and growth factors has been applied to periodontal regeneration; however, the mechanism of EMDs is largely unknown. The aim of this study was to investigate the effects of EMDs on the proliferation and release of growth factors from PDLCs. Materials and methods: Human PDLCs were removed from individually extracted 3rd molars of healthy young adults, and cultured in the media containing EMDs (Emdogain, Biora, Malmo, Sweden) at concentration of 0, 12.5, 25, 50, 100, and $200{\mu}g/mL$ each. Cell proliferation and ALP (alkaline phosphatase) activity were measured. The evaluation of growth factors released by PDLCs was also performed by one-way analysis of variance (ANOVA) and Bonferroni's multiple comparison test. Results: Significantly increased proliferation and ALP activity were observed in PDLCs treated with over $25{\mu}g/mL$ and $50{\mu}g/mL$ EMDs, respectively. Additionally, treatment of PDLCs with $50{\mu}g/mL$ resulted in significantly increased release of vascular endothelial growth factor (VEGF) and transforming growth factor $(TGF)-{\beta}$ after 24 h and 48 h, respectively. Conclusion: EMDs enhance the proliferation and ALP activity of PDLCs, and promote the release of growth factors, including VEGF and $TGF-{\beta}$, from PDLCs. Therefore EMDs could be one of the effective methods for periodontal regeneration.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.113-113
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• 1999

최근의 고품질 III-N 화합물 반도체 박막성장과 더불어 청색계열의 LED 및 LD의 성공적인 실현은 본 연구분야에 대한 새롭고 헌신적인 상업적, 학문적/ 기술적 투자환경을 유도해 나가고 있다. 특히, c-축 배향 단결정 사파이어를 기판재료로 사용하고 얇은 GaN buffer의 사용은 고온에서 그 위에 성장되는 성장박막의 특성을 크게 향상시키는 것으로 알려져 있다. 그러나 절연체를 기판으로 사용함에 따른 소자구조 및 제작공정의 복잡성과 기판과 GaN 박막사이의 큰 격자 부정합에 따른 결함센터 등은 소자의 전기, 광학적, 구조적 특성에 부정적인 영향을 미치고 있다. 이러한 문제점을 해결하고 양질의 박막을 성장하기 위한 GaN 혹은 그 대체 기판의 개발에 많은 연구투자가 이루어지고 있는 현실 속에서 Si을 기판으로 이용한 GaN 성장의 가능성이 조심스럽게 점쳐지고 있다. 현재까지의 연구결과를 참조할 때 대체로 복잡한 interlayer를 사용하여 박막성장이 일부 이루어졌으나 그 재현성이나 성장의 중요인자에 대한 해석은 아직 분명하게 밝혀져 있지 않다. 본 연구에서는 원자적 관점에서 Si의 표면에 일부 변화를 유도하고, MOCVD 방법으로 그 위에 성장되는 GaN 박막의 광학적 및 표면 morphology 등에 미치는 영향을 분석하여 핵심적인 성장인자를 추출하고자 시도하였다. 성장된 GaN/Si 박막의 물성은 SEM(AFM), PL, XRD, Auger depth profile 장비등을 이용하여 조사하였으며 사파이어 기판 위에 성장된 GaN 박막의 특성들과 비교 검토하였다.

• KSBB Journal
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• v.18 no.3
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• pp.207-210
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• 2003

The locus coeruleus (LC) contains about half of the total number of noradrenergic neurons in the brain and those noradrenergic neurons from the LC innervate entire brain regions. The LC is a major common target region in several neurodegenerative disorders such as Alzheimer's, Pakinson's and Huntington's diseases. The brain-derived neurotrophic factor (BDNF) regulate neuronal cell survival and differentiation of central nervous system neurons, including LC noradrenergic neurons. In this study, various small molecules and growth factors were tested as candidates to promote the production of BDNF in LC noradrenergic neuronal cells. The molecules tested include neuropeptides, cytokines, growth factors, neurotransmitters, and intracellular signaling agents. Four small molecules or growth factors, FGF8b, BMP-4, forskolin, and dibutyryl cGMP, were found to increase the release of BDNF in LC noradrenergic neurons. Especially, BMP-4 significantly enhanced BDNF production over 2.5-fold in LC noradrenergic neurons.