• 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.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.295-300
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• 2011

국내 건축물 외장재의 화재위험성 판단을 위한 기준 설정 및 건축물 외장재 수직확산 방지를 위하여 국내 외 실규모 화재실험을 비교 분석하였다. 현재 미국, 영국 등의 화재안전선진국들에서는 NFPA 285, BS 8414-1 등의 실대형 화재 실험을 통하여 외장재의 화재위험성을 판단하고 있다. 이에 본 연구에서는 국내 외 건축물 외장재의 수직화재확산 성능 평가 방법들의 비교 분석을 통하여 국내 실정에 맞는 실대형의 화재실험 방법을 결정하고자 하였다. 본 결과를 통해 건축물의 단위 공간에서 화재가 발생하여 화재의 성장이 플래시오버에 도달한 후 창문 등의 개구부를 통하여 화염이 출화되었을 때 이러한 화염에 의한 건축물 외장재의 수직화재 확산 성능 평가하는 건축물 외장재 수직확산 실대형 화재실험 장비를 개발하고자 하였다.

• Journal of the Korea Concrete Institute
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• v.16 no.3 s.81
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• pp.311-318
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• 2004

This study was performed to examine engineering properties for planting of porous concrete block containing rice straw ash. Tests for void ratio, compressive and flexural strength, pH by neutralization treatment time and curing method were peformed. As results, the void ratio tends to decrease with increasing rice straw ash content. But, the compressive and flexural strength tends to increase with Increasing rice straw ash content. When the neutralization was treated at the curing age 6 days, the greatest strength was showed. The pH of porous concrete without neutralization treatment in dry and water curing are shown in 10.32 ${\~}$ 10.55 and 9.41${\~}$9.59, respectively. The pH of porous concrete by neutralization treatment in dry and water curing were shown in 9.74${\~}$10.10 and 8.13${\~}$9.32, respectively. The porous concrete block size was 23 ${\times}$ 23 ${\times}$ 4 cm, and species of planting were Tall fescue, Lespedeza cyrtobotrya and Lespedeza cuneata. At the 6 months after seeding, germination ratio and grown-up length of Tall fescue, Lespedeza cyrtobotrya and Lespedeza cuneata were shown in 90, 60, $50\%$, and 40${\~}$50, 90${\~}$110, 65${\~}$75 cm, respectively. These porous concrete block containing rice straw ash could be used for planting.

• Journal of Aquaculture
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• v.22 no.1
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• pp.112-117
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• 2009

This study were conducted to investigate the effects of several additives in experimental diets on the growth, feed utilization and body composition of juvenile and grower rockfish. Three replicates of juveniles (3.6 g/fish) and two replicates growers (166 g/fish) were fed the experimental diets containing herb medicines mixture, Artemisia asiatica and Epimedium koreanum for 8 weeks. Dietary supplementation with herb medicines mixture had no beneficial effects on growth and feed utilization of juvenile fish. Weight gain, daily feed intake, condition factor and hepatosomatic index of grower fish fed the diet were not affected by dietary additive (P>0.05). Peed efficiency and protein efficiency ratio of grower fish fed the diet containing herb medicines mixture were significantly higher than those of fish fed the control diet (P<0.05), but not significantly different from fish fed the diet containing A. asiatica and E. koreanum (P>0.05). Proximate analysis of whole body, muscle, viscera and liver in the juvenile and grower were not affected by dietary additives (P>0.05). The results of this study suggest that feed efficiency and protein efficiency ratio of grower rockfish may improved by herb medicines mixture supplementation in the diet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.542-549
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• 2021

The purpose of this study was to provide an economical and easy preparation method for recombinant human epidermal growth factor (rhEGF) without the need for an expensive enzyme to cleave the fusion part. However, the N-terminal fusion part is still useful for affinity chromatography. The hEGF is an important hormone in cell growth and proliferation in humans, and many studies on the expression and purification of this protein have been reported. In the present study, the hEGF gene was designed to be optimized with the E. coli codon usage preference and to contain Asn-Gly at the N-terminus of the protein. The gene was inserted into pRSET_A, an E. coli expression vector, and transformed into E. coli BL21 (DE3). The recombinant fusion protein was successfully co-expressed with pG-Tf2, a chaperone vector, in E. coli and purified by Ni-NTA column chromatography. The rhEGF was then released by hydroxylamine treatment and confirmed by SDS-PAGE. ELISA analysis showed that the activity of the free rhEGF was more than 92% similar to that of commercial EGF. The biological activity of the rhEGF was confirmed by a cell proliferation test with human skin fibroblasts.

• Journal of the Korean Vacuum Society
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• v.12 no.1
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• pp.70-77
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• 2003

It is well Down that the growth of carbon nanotubes (CNTs) by chemical vapor deposition (CVD) using a transition metal catalyst is greatly enhanced in a nitrogen environment. We show here that the enhanced growth is closely related to the activated nitrogen and it's incorporation into the CNT wall and cap during growth. This behavior is consistent with theoretical calculations of CNx thin films, showing that nitrogen incorporation to the graphitic basal plane reduces the elastic strain energy for curving the graphitic layer. Enhanced CNT growth by nitrogen incorporation is thus due to a decrease in the activation energies required for nucleation and growth of the tubular graphitic layer.

• Journal of the Korean Vacuum Society
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• v.4 no.S1
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• pp.196-201
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• 1995

새로운 증착방법인 UHV-ECRCVD를 이용하여 기판온도 $440^{\circ}C$의 저온에서 격자이온이 일어나지 않고 완벽한 정합상태를 유지하고 있는 무전위 SiGe 에피박막을 성장시켰다. 박막의 두께는 기계적 평형이론(mechanical equilibrium theory)인 Mattews-Blakeslee 임계두께를 초과하였으며, 따라서 본 연구에서 사용하는 낮은 기판온도에 의해 격자이완이 억제되고 있음을 알았다. 한편 성장시에 가해주는 GeH4의 유량이 증가함에 따라 박막내에 GeH4으로부터 생성된 무거운 ion의 기판입사량이 증가하여 격자손상(lattice damage)에 의한 결함이 증가하므로 높은 Ge 함량을 갖는 무전위 SiGe 에피박막을 얻을 수 없었다. 그러나 전체압력을 증가시켜서 에피층을 성장시키면 격자손상에 의한 결함은 생성되지 않았으며, 따라서 전체압력을 증가시키면 높은 Gegkafid을 갖는 무전위 SiGe 에피박막을 성장시킬 수 있을 것이라고 생각된다. 이것은 전체압력 증가로 인해 ECR 플라즈마 안의 전자온도가 감소하여 성장을 주도하는 활성종(reactive species)이 ion에서 radical 로 바뀌기 때문이라고 추정하였다. 본 연구에서는 박막의 Ge 함량이 증가함에 따라 에피층의 성장속도가 증가하는 현상을 관찰하였다. 따라서 ECR 플라즈마를 사용하는 본 연구에서도 표면에서의 수소탈착이 성장속도결정단계임을 알 수 있었다. 한편 인입률(incorporation ratio)은 1에 근접하였으며, 이것은 플라즈마에 의한 원료기체의 분해과정이 thermal CVD와는 달리 무차별적으므로 SiH4과 GeH4의 분해효율이 크게 다르지 않기 때문이라고 추정하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.4
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• pp.141-148
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• 2006

Skull melting method can be a good candidate for growing oxide single crystals with high quality and for mass production because of its low production costs and high yield through recycling of crust. In this study, rutile single crystals were frown by the skull melting method and ingot characteristics with the variation of different growth conditions has been investigated. Conditions for high quality rutile ingot growth were used for producing cold-crucible size of ${\Phi}12cm{\times}H14cm$, capacity of 3000 pF tank condenser, work frequency of 2.84 MHz, melt-dwelling time of 9hrs and growing speed of 2 mm/h.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.21-21
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• 2003

목적： 악성뇌종양 주변부위의 역동자기공명영상에서의 시간신호강도곡선 양상으로 종양의 성장 양상이나 예후를 판단할 수 있는지를 알고자 한다. 대상 및 방법： Anaplastic oligodendroglioma 3예, Anaplastic astrocytoma 1예, Glioblastoma multiforme 1예, Malignant ependymoma 2예, Medulloblastorna 1예로서, 총 8예의 종양절제전, 혹은 후의 잔류 종양을 대상으로 하였다. Routine MRI에 추가하여 종양부위에서 Turbo spin echo T1 강조 역동자기공명영상을 하였으며, Gd-DTPA 0.1 mmol/kg를 급속 주사 한 후, TR/TE, 350/15, slice thickness 6 mm, slice number 3, NEX 2회, scan time은 15 초로 하여 5 분 동안 20회 영상을 얻었다. 가시적으로 조영증강이 없는 종양의 주변부위나 수술경계부위에 관심영역을 그려서 시간신호강도곡선을 얻었으며, 첫 회 조영제 통과시의 peak 이후에 신호가 감소하는 경우를 Normal pattern으로, peak 이후에 신호가 계속 유지되거나 증가하는 경우를 Tumor pattern으로 하였으며, Normal pattern과 Tumor pattern을 보인 예들을 구분하여 종양의 재성장 상태와 환자의 생존 기간을 비교 관찰하였다.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.269-271
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• 2005

본 연구는 수선화 구근의 각 조직으로부터 기내배양시 캘러스형성과 신초재분화를 위한 성장조절제의 효과를 측정하기 써하여 시행되었다. 신초형성과 callus의 형성은 기저부를 포함하는 floral axis에서 $50\%$의 신초발아율을 관찰하였고 scale 에서는 신초형성이 거의 관찰되지 않았다. 그리고 floral axis만을 치상한 경우는 아주 저조한 신초형성율이 관찰되었다. 지저부를 포함한 floral axis의 신초형성은 callus의 형성과 같은 NAA 0.5 mg/L과 BA 1.0 mg/L을 포함하는 MS 배지에서 만족할만한 결과를 얻었다. 신초형성으로부터 모든 신초가 형성되기까지는 약 140일이 소요되었다. 신초가 형성된 구근조직을 NAA 5.0 mg/L과 TDZ 0.02 mg/L을 포함하는 뿌리유도 MS배지에서 뿌리가 유도되는 결과를 얻었다. 본 실험에서는 수선화의 재 분화에 있어서 구근의 조직에 따라 신초형성이 다르게 나타남을 발견 할 수 있었다.