• 제목/요약/키워드: differentiation-resistance

검색결과 131건 처리시간 0.026초

암반에 근입된 강관말뚝의 수평방향 지지거동 연구 (Analysis of Lateral Behavior of Steel Pile embedded in Basalt)

  • 김기웅;박정준;김진우
    • 한국지반신소재학회논문집
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    • 제15권1호
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    • pp.1-10
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    • 2016
  • 최근 해상풍력발전 단지 조성은 많은 양의 에너지를 창출할 수 있어 그 기대는 점차적으로 증가하고 있다. 특히 제주도는 풍황이 우수하여 해상풍력발전 시스템 운영을 위한 최적의 대상지이기는 하나, 화산활동에 의해 형성된 지형으로 육지부와 달리 현무암층 사이에 연약층인 화산쇄설물 및 공동이 불규칙하게 발달된 층상구조로 이루어져 있다. 이에 본 연구에서는 제주현무암의 p-y 곡선을 얻기 위한 수평재하시험을 실시하였다. 말뚝 수평재하시험중에 측정한 변형률 데이터로부터 p-y 곡선을 유도하기 위하여 수평변위(y)는 high order polynomial curve fitting 기법을 적용하고, 지반반력(p)은 piecewise cubic polynomial curve fitting 기법을 추천한다. 이는 지반반력을 계산하기 위하여 미분하는 과정에서 발생하는 에러를 최소화 할 수 있으므로 역해석을 통한 말뚝두부에서 하중-변위를 예측할 때 에러가 가장 작게 발생한다.

P-32를 이용한 벼멸구(Nilaparvata lugens Stal) 저항성 검정법에 관한 연구 (Feasibility in Differentiation of Resistance of Rice Varieties to Brown Planthopper (Nilaparvata lugens Stal) using Radisoisotope (P-32) Tracer-Technique)

  • 정규회;권신한;최승윤
    • 한국응용곤충학회지
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    • 제20권4호
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    • pp.207-211
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    • 1981
  • 수도 주요해충 벼멸구의 내충성품종선별방법을 개발하기 위하여 방사성동위원소 P-32를 이용한 섭식량과 식이선호성과의 관계를 조사중 다음과 같은 결과를 얻었다. 1. 식이선호에 의한 벼멸구의 선호도와 P-32 섭식량간에는 밀접한 관계가 있었다. 2. $ 2\~3$엽기 수도유묘를 표식할 때는 P-32의 비방사능이 $0.1{\mu}Ci/cc$가 되게 하고 처리방법은 근부를 24시간 이상 침적시킨 후 공시충은 48시간 흡즙시키는 것이 품종간차이를 비교하기 용역하였다. 3. 내충성 검정시 공시충은 성충을 이용하고 웅충보다 자충을 이용하는 것이 흡즙량의 차이가 커서 비교하기가 편리하였다.

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생장조절제 처리에 따른 과수화상벙 저항성 사과대목의 기내 식물체 유도 (Induction on in vitro Plant Regeneration the Apple Rootstocks of Fire Blight Resistance by Plant Growth Regulators)

  • 권영희;최원일;김희규;김경옥;김주형;송용섭
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2021년도 춘계학술대회
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    • pp.23-23
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    • 2021
  • Apple (Malus×domestica Borkh.; Rosaceae) is an important fruit crop grown mainly in temperate regions of the world. Tissue culture in vitro is a biotechnological technique that has been used to genetically improve cultivars (scions) and rootstocks. This could be important in the production of genetically uniform scions and rootstocks for commercial apple production. In nurseries, apple plants are produced by grafting scions onto rootstocks. The Cornell-Geneva (Geneva® series) breeding program has bred several dwarf rootstocks that are resistant to diseases and pests and are also cold hardy. This study was conducted to determine the optimal medium strength to improve sprouting shoot rate of apical meristem of the apple rootstocks of fire blight resistance. The apple rootstocks apical meristem at size (0.2 mm to 0.3 mm) with axillary buds were cultured on the MS(Murashige & Skoog) medium supplemented with plant growth regulators. The sprouting ratio and growth characteristics was evaluated after eight weeks in vitro culture. The highest rate of bud differentiation and shoot formation were 23.8% and 55.6%, respectively. After 6 weeks, shoots were regenerated from apical meristem, and their growth characteristics was significantly varied on the respective basal medium with different plant growth regulators. Our studies showed that the apple rootstocks the apple rootstocks of fire blight resistance plantlets could be successfully produced from apical meristem differentiated out of young twigs via organogenic regeneration.

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Functions of MAPK Cascade Pathways in Plant Defense Signaling

  • Cheong, Yong-Hwa;Kim, Min-Chul
    • The Plant Pathology Journal
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    • 제26권2호
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    • pp.101-109
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    • 2010
  • Protein phosphorylation is one of the major mechanisms for controlling many cellular processes in all living organisms. Mitogen-activated protein kinase (MAPK) cascades are known to transducer extracellular stimuli to several cellular processes, including cell division, differentiation as well as responses to various stresses. In plants, several studies have revealed that MAPK cascade pathways play an important role in responses against biotic and abiotic stresses, including wounding, pathogen infection, temperature, drought, salinity and plant hormones. It is also known that MAPK cascades-mediated signaling is an essential process in the resistance step to pathogens by regulating the activity of transcription factors. Here, the insights into the functions of MAPK cascade pathways in plant defense response signaling from Arabidopsis, tobacco and rice are described.

Emerging Roles of Krüppel-Like Factor 4 in Cancer and Cancer Stem Cells

  • Ding, Bo;Liu, Ping;Liu, Wen;Sun, Ping;Wang, Chun-Ling
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권9호
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    • pp.3629-3633
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    • 2015
  • Cancer stem cells (CSCs) are rare subpopulations within tumors which are recognized as culprits in cancer recurrence, drug resistance and metastasis. However, the molecular mechanisms of how CSCs are regulated remain elusive. Kr$\ddot{u}$ppel-like factors (KLFs) are evolutionarily conserved zinc finger-containing transcription factors with diverse functions in cell differentiation, proliferation, embryogenesis and pluripotency. Recent progress has highlighted the significance of KLFs, especially KLF4, in cancer and CSCs. Therefore, for better therapeutics of cancer disease, it is crucial to develop a deeper understanding of the mechanisms of how KLF4 regulate CSC functions. Herein we summarized the current understanding of the transcriptional regulation of K LF4 in CSCs, and discussed the functional implications of targeting CSCs for potential cancer therapeutics.

CONFORMATIONALLY RESTRICTED DIACYLGLYCEROL ANALOGUES AS ULTRAPOTENT PROTEIN KINASE C LIGANDS - A. State in general terms the purpose and object of the research

  • Lee, Jeewoo
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 제3회 추계심포지움
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    • pp.49-57
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    • 1995
  • Protein kinase C (PK-C) represents a central element transducing signals generated by a broad range of pathways which produce the lipid second messenger sn-1,2-diacylglycerol (DAG) directly or indirectly. Many dominant oncogenes have proven to function, at least in part, through this pathway Likewise, this pathway is involved in expression of other aspects of the transformed phenotype, such as tumor invasion or multidrug resistance. As expected from its broad role in cell signaling, PK-C Is also important in a range of other physiological and pathophysiological processes, including inflammation, differentiation, and nerve function.

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반수체 담배의 엽육 원형질체로부터 MNNG 처리에 의한 Glyphosate 저항성 클론의 선별 (Selection of Glyphosate-Resistant Clones form MNNG-treated Mesophyll Protoplasts of Haploid Tobacco Plants)

  • 성순기
    • Journal of Plant Biology
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    • 제36권1호
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    • pp.105-112
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    • 1993
  • Selection of glyphosate-resistant clones from MNNG-treated mesophyll protoplasts of haploid tobacco and their differentiation were studied. The protoplasts were treated with 0.1 to 100 $\mu\textrm{g}$/mL N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for 30 min when they expanded to oval shapes. After the treatment, the protoplasts in 4-16 cell stages were transferred to the selective medium containing 1 mM glyphosate for the selection of the glyphosate-resistant colonies. The efficiency of the cell division of the protoplasts in the selective medium decreased as the MNNG concentrations in creased. Optimal MNNG concentration for induction of the glyphosate-resistant clones was 10$\mu\textrm{g}$/mL and mutation frequency was 2.66$\times$10-6. The stability of the glypohsate-resistance of the clones was examined by prolonged subculture in the medium with 1 mM glyphosate, and the resistant clones were survived more than 10 months. Among them one clone has been proliferating and greening and the others were proliferating without greening or greening with slower proliferating.

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Genomic polymorphism in clinical mycobacterial strains analyzed by pulsed-field gel electrophoresis

  • Kim, Jeong-Ran;Kim, Cheorl-Ho
    • Journal of Microbiology
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    • 제35권3호
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    • pp.172-176
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    • 1997
  • The Mycobacterium tuberculosis clinical isolates in Korea, showing different drug resistances, were analyzed by comparing large restriction fragment (LRF) patterns produced y digestion of genomic DNA with infrequent-cutting endonucleases of SpeI, AsnI and pulsed-field gel electrophoresis (PFGE). SpeI and AsnI allowed with AsnI and SpeI, strains yielded an absolutely identical pattern for Korean type's mycobacteria even though they showed different drug resisstance. However, when three M. tuberculosis strains, showing drug resistance, were digested with XbaI, patterns were different from those of the other M. tuberculosis strians which are susceptible to drugs. This stuyd reveals that the comparison of chromosomal restriction patterns is very useful as an additional aid for the differentiation and identification of M. tuberculosis strains showing drug resistances.

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MC3T3-E1 세포주에서 황기.계지.황백 처방(BHH10)의 골형성 촉진 효능 연구 (Effects of Astragalus Membranaceus, Innamomum Cassia, Phellodendron Amurensis(BHH10) on MC3T3-E1 Cells Proliferation, Differntiation and Bone Mineralized Formation)

  • 이미림;허정은;남동우;선종인;강중원;김성훈;최도영;이재동
    • Journal of Acupuncture Research
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    • 제29권6호
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    • pp.11-21
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    • 2012
  • Objectives : BHH10 is traditional medicine herb used for enhancing body resistance against various diseases. The aim of this study was to identify BHH10 extract induces osteogenic activity in human osteoblast-like MC3T3-E1 cells. Methods : MC3T3-E1, pre-osteoblast cell line, were treated with BHH10 of various concentrations($0.1{\mu}g/mL$, $1{\mu}g/mL$, $10{\mu}g/mL$). And then, the effect of BHH10 on osteoblast differentiation was examined by alkaline phosphatase(ALP) activity, von Kossa staining and RT-PCR for osteoblast differentiation markers such as osteocalcin(OCN), osteopontin(OPN). Results : BHH10 had dose-dependent effect on the viability of osteoblastic cells, and dose-dependently increased alkaline phosphatase(ALP) activity. BHH10 markedly increased mRNA expression for OCN, OPN in MC3T3-E1 cells. Also, BHH10 significantly induced mineralization in the culture of MC3T3-E1 cells. Conclusions : In conclusion, these results propose that BHH10 can play an important role in osteoblastic bone formation, osteogenesis, and may possibly lead to the development of bone-forming drugs.

Development of a Human Mammary Epithelial Cell Culture Model for Evaluation of Drug Transfer into Milk

  • Kimura Soichiro;Morimoto Keiko;Okamoto Hiroshi;Ueda Hideo;Kobayashi Daisuke;Kobayashi Jun;Morimoto Yasunori
    • Archives of Pharmacal Research
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    • 제29권5호
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    • pp.424-429
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    • 2006
  • In the present study, a human mammary epithelial cell (HMEC) culture model was developed to evaluate the potential involvement of carrier-mediated transport systems in drug transfer into milk. Trypsin-resistant HMECs were seeded on $Matrigel^{circledR}-coated$ filters to develop monolayers of functionally differentiated HMEC. Expression of the specific function of HMEC monolayers was dependent of the number of trypsin treatments. Among the monolayers with different numbers of treatment (treated 1 to 3 times), the monolayer treated 3 times (3-t-HMEC monolayer) showed the highest maximal transepithelial resistance and expression of $\beta-casein$ mRNA as an index of differentiation. Transport of tetraethylammonium (TEA) across the 3-t-HMEC monolayer in the basolateral-to-apical direction was significantly higher than that in the apical-to-basolateral direction (p<0.05), whereas such directionality was not observed for p-aminohippurate, suggesting the existence of organic cation transporters, but not organic anion transporters. In fact, expression of mRNAs of human organic cation transporter (OCT) 1 and 3 were detected in the 3-t-HMEC monolayer. These results indicate that the 3-t-HMEC monolayer is potentially useful for the evaluation of carrier-mediated secretion of drugs including organic cations into human milk.