• 제목/요약/키워드: Initial growth

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5083-H115 알루미늄 합금의 혼합 모우드 피로 균열성장 특성 (Mixed-mode fatigue crack growth behaviors in 5083-H115 aluminum alloy)

  • 옹장우;진근찬;이성근;김종배
    • 대한기계학회논문집
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    • 제13권3호
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    • pp.461-471
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    • 1989
  • 본 연구에서는 혼합 모우드 균열문제의 연구를 위하여 .KAPPA.$_{II}$ /.KAPPA.S1I\ulcorner조절이 간편하고, 균열진전경로가 하중방향에 따른 균일전면의 자유표면의 영향을 균일하게 한 시험편(이하 RCM 또는 round compact mixed-mode 시험편이라 한다)을 고안하여 균열길이 및 하중작용 방향에 따른 .KAPPA.$_{I}$ 및 .KAPPA.S1II를 수치해석한 다음 일반화 하였다. 또 고강도와 용접성이 요구되는 항공기부품, 압력용기, 지상운송차량 등에 사용되고 있는 5083-H115 알루미늄 합금에 대해 혼합 모우드 균열진전 방향 및 피로균열 진전특성을 분석하고자 한다.다.

참전복(Haliotis discus hannai)의 성장에 대한 감마선 영향 (Effect of Gamma Ray on Growth of Juvenile Abalone, Haliotis discus hannai)

  • 김경주;최미경;여인규
    • 환경생물
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    • 제25권2호
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    • pp.107-114
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    • 2007
  • 특정 선량에서 감마선은 조직의 성장을 자극하거나 호르메틱 효과를 나타낸다. 참전복에 다른 양의 감마선을 조사한 후 성장과 생존율에 미치는 효과를 2004년 2월부터 2005년 1월까지 관찰하였다. 각장의 성장은 평균 $3.45{\sim}0.4cm$ 참전복에게 $0{\sim}20Gy$방사선을 조사한 후 48주 동안 관찰하였다 가장 높은 성장은 4 Gy 조사군에서 관찰되었고, 20 Gy 조사군에서 가장 낮은 성장이 관찰되었다. 방사선 조사에 따른 전복내의 생화학적 기전의 변화에 대한 연구가 추가적으로 시행되어야 할 것이다. 방사선을 이용한 전복의 성장과 물질대사의 지속적인 연구는 양식 산업에 이익 창출에 이바지 할 수 있을 것으로 사료된다.

Visible light-cured glycol chitosan hydrogel dressing containing endothelial growth factor and basic fibroblast growth factor accelerates wound healing in vivo

  • Yoo, Youngbum;Hyun, Hoon;Yoon, Sun-Jung;Kim, So Yeon;Lee, Deok-Won;Um, Sewook;Hong, Sung Ok;Yang, Dae Hyeok
    • Journal of Industrial and Engineering Chemistry
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    • 제67권
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    • pp.365-372
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    • 2018
  • Wounds that heal with excessive scar formation result in poor functional and aesthetic outcomes. To address this, in our study, visible light cured glycol chitosan (GCH) hydrogels containing endothelial growth factor (EGF) and basic fibroblast growth factor (bFGF) were prepared (GCH-EGF, GCH-FGF and GCH-EGF/FGF) and evaluated their efficacies on the improvement of wound healing in vivo. In vitro release test showed that the growth factors were released in a sustained manner along with initial burst for 24 h. In vitro cell proliferation assay of L-929 mouse fibroblast cell line resulted in the superior ability of GCH-EGF/FGF on the rate. In vivo results demonstrated that the growth factor loaded GCHs further enhanced wound healing compared with GCH. In particular, GCH-EGF/EFG showed the most remarkable wound healing effect among the samples.

소아 성장에 대한 한의학 치료: 국내 임상연구에 대한 문헌적 고찰 (Treatments of Korean Medicine for Pediatric Growth: A Literature Review of Clinical Studies)

  • 한지은;안뜰에봄;박장경;성현경;연지혜;성수현
    • 대한한방소아과학회지
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    • 제35권1호
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    • pp.18-29
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    • 2021
  • Objectives The purpose of this study is to provide evidence of treatment of growth disorder Methods We have reviewed clinical studies of growth disorder in children and adolescent through 6 databases until February, 2020. The searching keywords were "short stature OR dwarfism OR growth disorder" AND "acupuncture OR electric acupuncture OR electroacupuncture OR moxibustion OR herb medicine OR cupping OR Korean medicine OR oriental medicine OR chuna OR pharmacopuncture OR qigong OR traditional medicine OR traditional Korean medicine OR Korean medicine". There was no limit to time and language. Results As a result of the initial search, a total of 270 papers from six domestic databases were found. Among these papers, 156 papers were selected after excluding duplicated papers, and 109 of them were further excluded after checking the title and the abstract. Additionally, 28 papers were excluded by reviewing the full text. The author, year, number of patients, treatment, evaluation tools, and results of a total of 19 papers were included in this study and were summarized. 90.5% of the studies have shown that herbal remedies have improved childhood growth. Conclusions Random control studies and large-scale observational studies are needed in future to show high-quality evidence for the treatment of Korean medicine in pediatric growth.

애엽을 포함하는 해애탕의 에탄올 추출물이 제모된 C57BL/6 마우스의 발모에 미치는 영향 (Haeae-tang including Artemisia argyi Folium promotes hair growth in hair-removed C57BL/6 Mice)

  • 김남희;문선희;김미려;이영선;유왕근
    • 대한본초학회지
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    • 제30권2호
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    • pp.19-24
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    • 2015
  • Objectives : The experiment was performed to investigate promotive effects of haeae-tang (HET) extract, a traditional Korean medicinal recipe, on hair growth, protein and gene expression in hair-removed C57BL/6. Methods : In experiment, animals were divided into 3 groups including normal (vehicle), HET ethanol extract and 5% minoxidil-treated groups (Minoxidil, positive control). The vehicle or testing samples were daily treated with 0.2ml per on hair-shaved dorsal skin of C57BL/6mice for 15 days. Effects of testing samples on hair growth was monitored through phototrichogram analysis by folliscope on the initial, $5^{th}$, $10^{th}$, $15^{th}$ day, respectively. Also, gene and protein expressions of vascular endothelial growth factor (VEGF) and Insulin like growth factor-1 (IGF-1), relevant to hair growth, were examined. Results : Hair density and hair thickness of Minoxidil treated-group was significantly increased compared to that of vehicle application on the $15^{th}$day, respectively. Dorsal hair density of HET treated-group was significantly increased compared to that of vehicle application on the $15^{th}$day. In addition, the Minoxidil group significantly increased the expression of cutaneous IGF-1 protein and mRNA compared to that of the vehicle-applied group on the $15^{th}$ day. And HET-treated group significantly increased the expression of dorsal VEGF protein compared to that of the vehicle-applied group on the $15^{th}$ day. Conclusions : These results suggest that this Korean medicinal recipe, HET has promoting activity on hair growth in an Alopecia animal model thus it can be used as a material of agent or products for improvement or prevention of alopecia.

Effects of Pretense Inhibitors and Antioxidants on In Vitro Survival of Porcine Primordial Germ Cells

  • Lee, Chang-Kyu;Jorge A. Piedrahita
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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    • pp.47.1-47
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    • 2001
  • One of the problems associated with in vitro culture of primordial gern cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of the porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally, \ulcorner2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p<0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layer, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of \ulcorner2-macroglobulin and antioxidatns can increase the number of PGCs in vitro by suppressing apoptosis.

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석탄회 고형물의 파괴특성에 관한 실험적 연구 (Experiment Study for Fracture Characterist of the Ash solid)

  • 조병완;박종빈;김효원
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.335-340
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    • 2002
  • By the recently, Environmental pollution is serious by the highly economic growth and expansion of lively country basic industry. Especially, in case of industrial waste and life waste leaped into a pollution source. Also, research for processing of waste and recycling countermeasure is a pressing question on national dimension because it is prohibited an ocean disposal and reclamation. In this study, it looked for fracture characteristic value of recycling a coal ash to decrease environmental pollution by picky and exhaustion of natural resources and to reduce self-weight to prepare for a tall building and earthquake. So a coal ash examined to be possible to do as construction material. It achieved compressive strength test and three points bending test with initial notch depth rate and age for variables to show a basic research data. From the basis of the three points bending test, the fracture parameters - notch sensitivity, fracture energy, initial compliance were experimentally proposed. From the results of the compressive strength test, the elastic modulus was experimentally proposed. Also on the basis of the three points bending test, the fracture parameters - notch sensitivity, fracture energy, initial compliance were experimentally proposed. The results that the strength and fracture energy value are lower than concrete or mortar is described in this paper. Also, it shows that the deflection at fracture decreases as the age increases and the notch sensitivity decrease. However, it is judged to be available to construction material if research is continuously gone forward.

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유동층 반응기에서 Candida tropicalis 균에 의한 페놀함유 폐수처리에 관한 연구 (The Phenol Wastewater Treatment by Candida tropicalis in Fluidized Bed Biofilm Reactor)

  • 김우식;염경호;김응식
    • 한국미생물·생명공학회지
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    • 제13권1호
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    • pp.33-39
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    • 1985
  • The effects of initial concentration, flow rate, and recycle ratio on the removal efficiency of phenol were studied in a tapered fluidized bed reactor packed with activated carbon which was attached with Candida tropicalis. The optimum conditions of Candida tropicalis were showed that pH was 7.0 and temperature was $30^{\circ}C$, and the specific growth rate of Candida tropicalis was satisfied with the Monod equation up to 500 mg/L of phenol, and beyond it the inhibition of substrate was found. According to the increases of initial concentration and flow rate, the removal efficiency was decreased, as the recycle ratio was increased, the removal efficiency was increased. In the case of flow rate of 10mL/sec and the recycle ratio of 2, the removal efficiency was 90% above for the all of initial concentration. The removal rate of phenol was the first order reaction in this system, and the rate equation of reaction was as follows.

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Fatigue life prediction of multiple site damage based on probabilistic equivalent initial flaw model

  • Kim, JungHoon;Zi, Goangseup;Van, Son-Nguyen;Jeong, MinChul;Kong, JungSik;Kim, Minsung
    • Structural Engineering and Mechanics
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    • 제38권4호
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    • pp.443-457
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    • 2011
  • The loss of strength in a structure as a result of cyclic loads over a period of life time is an important phenomenon for the life-cycle analysis. Service loads are accentuated at the areas of stress concentration, mainly at the connection of components. Structural components unavoidably are affected by defects such as surface scratches, surface roughness and weld defects of random sizes, which usually occur during the manufacturing and handling process. These defects are shown to have an important effect on the fatigue life of the structural components by promoting crack initiation sites. The value of equivalent initial flaw size (EIFS) is calculated by using the back extrapolation technique and the Paris law of fatigue crack growth from results of fatigue tests. We try to analyze the effect of EIFS distribution in a multiple site damage (MSD) specimen by using the extended finite element method (XFEM). For the analysis, fatigue tests were conducted on the centrally-cracked specimens and MSD specimens.

Erlotinib에 대한 내성 발생 후 Gefitinib에 반응한 진행성 폐선암 1예 (Successful Rechallenge with Gefitinib for an Initial Erlotinib-Responder with Advanced Lung Adenocarcinoma)

  • 홍성철;심윤수;이진화;류연주;장중현
    • Tuberculosis and Respiratory Diseases
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    • 제71권4호
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    • pp.286-290
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    • 2011
  • Although failure of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKI) is generally believed to be associated with cross-resistance to other EGFR TKI, the benefit of administering erlotinib as a second EGFR TKI after resistance of gefitinib as the first TKI has been well known. However, good response to gefitinib after an initial response to erlotinib has been rare. We report that a 45-year-old woman (never smoked), with lung adenocarcinoma and EGFR mutation, showed an initial response to erlotinib, and then responded to gefitinib again.