• 제목/요약/키워드: Exogenous factor

검색결과 207건 처리시간 0.02초

Inhibitory Effects of Antisense RNA on Expression of Cholesteryl Ester Transfer Protein in Vaccinia Virus Expression System

  • Lee, Myung-Hoon;Jang, Moon-Kyoo;Park, Yong-Bok
    • BMB Reports
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    • 제28권3호
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    • pp.243-248
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    • 1995
  • Cholesteryl ester transfer protein (CETP), a hydrophobic glycoprotein promoting transfer of cholesteryl esters (CE) from high-density lipoproteins (HDL) to lower-density lipoproteins in the plasma, has been recognized a potent atherogenic factor during the development of coronary artery diseases. This study demonstrated a possible utilization of antisense RNA to inhibit expression of the CETP gene using vaccinia virus as an expression system. The CETP cDNA was inserted into a transfer vector (pSC11) in sense and antisense orientations and used to generate recombinant viruses. Recombinants containing sense or antisense orientations of the CETP cDNA were isolated by $TK^-$ selection and X-gal test. The inserted CETP cDNAs in the recombinants were identified by Southern blot analysis and allowed to transcribe in host cells (CV-1). Expressions of the exogenous CETP mRNA, extracted from the CV-1 cells coinfected with viruses containing sense and antisense DNAs, were monitored by Northern blot analysis using the CETP cDNA probe, by Western blot analysis using monoclonal antibody against the C-terminal active region of the CETP and by the CETP assay. Decreased expressions of the exogenous CETP cDNA were clearly evident in the Northern and Western blot analyses as the dose of antisense expression increased. In the CETP assay, the CETP activities decreased compared to the activity obtained from the cell extracts infected with sense construct only.

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인스타그램 이용자 성격이 브랜드 만족도와 충성도에 끼치는 영향 (Effects of Instagram User Personality on Brand Satisfaction and Loyalty)

  • 김혜빈
    • 한국콘텐츠학회논문지
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    • 제16권6호
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    • pp.450-461
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    • 2016
  • 본 연구는 SNS의 이용에 관한 영향요인을 탐색하기 위하여 이용자의 성격이 SNS 브랜드 만족도와 충성도에 끼치는 영향을 분석한다. 여러 가지 SNS 중 상대적으로 높은 이용률 증가를 보이는 인스타그램에 주목하고, 인스타그램 이용자 성격 요인 중 외향성, 호기심, 자존감 3개 요인을 외생변수로 정의하였다. 브랜드 만족도와 브랜드 충성도를 내생변수로 상정하고 성격 요인이 브랜드 충성도에 영향을 미치는 데 있어 브랜드 만족도를 매개변수로 상정하였다. 인스타그램 이용 경험이 있는 사용자를 대상으로 설문조사를 진행하였으며 총 396부의 설문조사 결과를 최종 분석 자료로 사용하였다. 연구 결과, 3개의 성격 요인 모두 브랜드 만족도에 정(+)의 영향을 끼쳤으며 브랜드 충성도에는 외향성과 호기심만이 정(+)의 영향을 끼쳤다. 브랜드 만족도는 매개변수로 검증되었으며 브랜드 만족도와 충성도에 가장 큰 영향을 끼치는 성격 요인은 호기심인 것으로 밝혀졌다.

도시공원녹지에 대한 실외위락기능과 만족도의 계량적 평가에 관한 연구 (A Study on the Quantitative Evaluation of Outdoor-Recreational Function and User Satisfaction with Urban Park and Open Space)

  • 박승범
    • 한국조경학회지
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    • 제18권4호
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    • pp.127-140
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    • 1991
  • The Primary purpose of this study is to investigate factors and variables which have significant effects on user satisfaction with recreational facilities in Taejong-Dae recreational complex, thereby establishing indices of planning and development of urban parks and open space. To test the causal models of this research, the date were gathered by self-administered questionnaires from 967 households in Pusan City which were selected by the multi-stage probability sampling methood. The analysis of the multi-stage primarily consists of two phase : The first analysis dealt exploratory factor analysis which identified major factors involved in satisfaction with recreational activities and facilities in Taejong-Dae recreational complex and the second analysis tested the fit of the causal models of this research by employing LISREL methodology. There are three advantages of using LISREL over other multivariate analysis methods : First, measurement error is allowed and calculated in LISREL, otherwise there is a risk of seriously misleading estimates of coefficients ; Second, LISREL deals with latent variables or unmeasured variables ; Third, it enables to test causal relations among variables. The factors analysis identified that five factors are involved in satisfaction with recreational facilities. The five factors of satisfaction with recreational facilities are space for repose and relaxation, active recreation facilities such as pool and zoo, physical exercise facility, convenience and maintenance facility, and linear facility, and linear facility for walking. The second phase analysis tested the fit of the causal models for satisfaction with recreational facilities to the data and identified statistically significant causal linkage among overall satisfaction with Taejong-Dae recreational complex, other endogenous factors and exogenous variables. Overall fits of both causal models were very good. Among endogenous factors, facility for repose and relaxation. linear facility for walking, active recreation facility, facility for convenience and maintenance were identified as having significant effects on overall satisfaction. Exogenous variables which have significant effects on endogenous variables wer also identified. These significant relationships indicate important factors and variables that should be considered in planning and development of the recreational complex. On the basis of these significant causal relationships, implications for planning and the delovepment of Taejong-Dae recreational complex were suggested.

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Embryo Survival on Day 25 of Generation in the Gilt is Not Affected by Exogenous Progesterone but is Correlated with Levels of Insulin-Like Growth Factor-I (IGF-I) mRNA in the Uterus

  • Yu, Z.;Gordon, J.R.;Kirkwood, R.N.;Thacker, P.A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권6호
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    • pp.862-867
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    • 1999
  • The present study was undertaken to determine the effect of administration of exogenous progesterone early in gestation on uterine levels of IGF-I mRNA and on embryo survival at day 25 of gestation in the pig. Forty-one prepubertal gilts were induced into oestrus with PG600 and artificially inseminated at their subsequent naturally occurring oestrus. Gilts were then randomly assigned to one of three groups. Gilts in the two treatment groups were injected intramuscularly with 50 mg of progesterone either from day 2 to 14 (N=14) or from day 4 to 14 (N=15) after breeding while those in the control group (N=12) were given corn oil (0.5 ml) from day 2 to 14. Between days 25 and 28 of gestation, gilts were slaughtered and reproductive tracts were recovered. Endometrial tissue (1 g) was collected and analysed for IGF-I mRNA levels using a reverse transcription-polymerase chain reaction, Progesterone treatment, starting either on day 2 or 4 after breeding, neither significantly increased embryo survival rate by day 25 of gestation nor altered IGF-I mRNA levels in uterine tissue. However, across all samples, the IGF-I mRNA level in the uterus was highly correlated with embryo survival rate (r=0.8193, p<0.01), supporting the involvement of IGF-I in the regulation of porcine embryo development.

Chronic Administration of Catechin Decreases Depression and Anxiety-Like Behaviors in a Rat Model Using Chronic Corticosterone Injections

  • Lee, Bombi;Sur, Bongjun;Kwon, Sunoh;Yeom, Mijung;Shim, Insop;Lee, Hyejung;Hahm, Dae-Hyun
    • Biomolecules & Therapeutics
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    • 제21권4호
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    • pp.313-322
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    • 2013
  • Previous studies have demonstrated that repeated administration of the exogenous stress hormone corticosterone (CORT) induces dysregulation in the hypothalamic-pituitary-adrenal (HPA) axis and results in depression and anxiety. The current study sought to verify the impact of catechin (CTN) administration on chronic CORT-induced behavioral alterations using the forced swimming test (FST) and the elevated plus maze (EPM) test. Additionally, the effects of CTN on central noradrenergic systems were examined by observing changes in neuronal tyrosine hydroxylase (TH) immunoreactivity in rat brains. Male rats received 10, 20, or 40 mg/kg CTN (i.p.) 1 h prior to a daily injection of CORT for 21 consecutive days. The activation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Daily CTN administration significantly decreased immobility in the FST, increased open-arm exploration in the EPM test, and significantly blocked increases of TH expression in the locus coeruleus (LC). It also significantly enhanced the total number of line crossing in the open-field test (OFT), while individual differences in locomotor activities between experimental groups were not observed in the OFT. Taken together, these findings indicate that the administration of CTN prior to high-dose exogenous CORT significantly improves helpless behaviors, possibly by modulating the central noradrenergic system in rats. Therefore, CTN may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression and anxiety disorders.

빅데이터 기술수용의 초기 특성 연구 - 기술이용자 및 기술활용자 측면의 조절효과를 중심으로 (A Study on Initial Characterization of Big Data Technology Acceptance - Moderating Role of Technology User & Technology Utilizer)

  • 김정선;송태민
    • 한국콘텐츠학회논문지
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    • 제14권9호
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    • pp.538-555
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    • 2014
  • 빅데이터와 관련 기술에 대하여 학계, 산업계, 공공의 관심이 크지만 아직까지 빅데이터 기술수용에 대하여 체계적으로 연구된 사례는 매우 드물다. 본 연구는 국내 초기 시장인 빅데이터 기술수용 연구를 위해 기술수용모델(TAM)을 중심 틀로 혁신확산이론(Innovation Diffusion Theory) 및 과업기술적합성(Task Technology Fit)이론을 통합적으로 활용하여 연구모형을 설정하였으며 빅데이터 기술 수용의 목적성을 기술수용모델의 조절변인으로 확장하였다. 연구결과 '주관적 규범'과 '과업기술적합성'이 TAM의 외생변인으로 가장 크게 영향을 가졌으며 기술기반의 새로운 서비스나 상품을 기획하고 개발하고자 하는 목적의 '기술활용자' 집단에게 '조직의 혁신성향'은 기술의 수용의도에 영향을 미치는 유의한 외생변인이나 단순히 기술을 이용하고자 하는 '기술이용자' 집단에게는 오히려 '주관적 규범'이 영향력을 가진 것으로 나타났다. 마지막으로 매개효과 검증에서도 유의한 차이점이 검증되었다.

The Arabidopsis Phytocystatin AtCYS5 Enhances Seed Germination and Seedling Growth under Heat Stress Conditions

  • Song, Chieun;Kim, Taeyoon;Chung, Woo Sik;Lim, Chae Oh
    • Molecules and Cells
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    • 제40권8호
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    • pp.577-586
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    • 2017
  • Phytocystatins (PhyCYSs) are plant-specific proteinaceous inhibitors that are implicated in protein turnover and stress responses. Here, we characterized a PhyCYS from Arabidopsis thaliana, which was designated AtCYS5. RT-qPCR analysis showed that the expression of AtCYS5 in germinating seeds was induced by heat stress (HS) and exogenous abscisic acid (ABA) treatment. Analysis of the expression of the ${\beta}-glucuronidase$ reporter gene under the control of the AtCYS5 promoter showed that AtCYS5 expression during seed germination was induced by HS and ABA. Constitutive overexpression of AtCYS5 driven by the cauliflower mosaic virus 35S promoter led to enhanced HS tolerance in transgenic Arabidopsis, which was characterized by higher fresh weight and root length compared to wild-type (WT) and knockout (cys5) plants grown under HS conditions. The HS tolerance of AtCYS5-overexpressing transgenic plants was associated with increased insensitivity to exogenous ABA during both seed germination and post-germination compared to WT and cys5. Although no HS elements were identified in the 5'-flanking region of AtCYS5, canonical ABA-responsive elements (ABREs) were detected. AtCYS5 was upregulated in ABAtreated protoplasts transiently co-expressing this gene and genes encoding bZIP ABRE-binding factors (ABFs and AREB3). In the absence of ABA, ABF1 and ABF3 directly bound to the ABREs in the AtCYS5 promoter, which activated the transcription of this gene in the presence of ABA. These results suggest that an ABA-dependent pathway plays a positive role in the HS-responsive expression of AtCYS5 during seed germination and post-germination growth.

Hydrogen sulfide ameliorates abdominal aorta coarctation-induced myocardial fibrosis by inhibiting pyroptosis through regulating eukaryotic translation initiation factor 2α phosphorylation and activating PI3K/AKT1 pathway

  • Yaling Li;Zhixiong Wu;Jiangping Hu;Gongli Liu;Hongming Hu;Fan Ouyang;Jun Yang
    • The Korean Journal of Physiology and Pharmacology
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    • 제27권4호
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    • pp.345-356
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    • 2023
  • This study aimed to assess the effects of exogenous hydrogen sulfide (H2S) on abdominal aorta coarctation (AAC) induced myocardial fibrosis (MF) and autophagy in rats. Forty-four Sprague-Dawley rats were randomly divided into control group, AAC group, AAC + H2S group, and H2S control group. After a model of rats with AAC was built surgically, AAC + H2S group and H2S group were injected intraperitoneally with H2S (100 µmol/kg) daily. The rats in the control group and the AAC group were injected with the same amount of PBS. We observed that H2S can improve left ventricular function and the deposition of myocardial collagen fibers, inhibit pyroptosis, down-regulate the expression of P-eif2α in myocardial tissue, and inhibit cell autophagy by activating the phosphatidylinositol 3-kinase (PI3K)/AKT1 signaling pathway (p < 0.05). In addition, angiotensin II (1 µM) H9c2 cardiomyocytes were injured in vitro experiments, and it was also observed that pyroptosis was inhibited after H2S (400 µmol/kg) intervention, the expression of P-eif2α in cardiomyocytes was significantly down-regulated, and the PI3K/AKT1 signaling pathway was activated at the same time. Therefore, increasing the expression of P-eif2α reverses the activation of the PI3K/AKT1 signaling pathway by H2S. In conclusion, these findings suggest that exogenous H2S can ameliorate MF in rats with AAC by inhibiting pyroptosis, and the mechanism may be associated with inhibiting the phosphorylation of eif2α and activating the PI3K/AKT1 signaling pathway to inhibit excessive cell autophagy.

도시공원 이용만족도에 기초한 도시공원의 개발방향에 관한 연구 - 부산시 대신자연공원을 사례로- (A Study on the Developmental Direction with Reference to User's Satisfaction of Urban Park -Cases study of Daeshin Natural Park in Pusan City-)

  • 임승범
    • 한국조경학회지
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    • 제19권3호
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    • pp.87-97
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    • 1991
  • The primary purpose of this study is to investigate factors and variables which have significant effects on user's satisfaction with recreational activities in Daeshin Natural Park, thereby establishing directions of development of urban parks. To test the causal models of this research, the data were gathered by self-administered questionnaires form 627 households in Pusan City which were selected by the multi-stage probability sampling method. The analysis of the data primarily consists of two-phase: The first analysis dealt exploratory factor analysis which identified major factors involved in satisfaction with recreational activities in Daeshin Natural Park and the second analysis tested the fit of the causal models of this research by employing LISREL methodology. The factor analysis identified that three factors are involved in satisfaction with recreational actitives. The three factors of satisfaction with recreational activities are facilities for health and phisical exercise, group recreational activity, maintenance activity. The second phase analysis tested the fit of the causal models for satisfaction with recreational activity to the data and identified statistically significant causal linkage among overall satisfaction with Daeshin Natural Park, other endogenous factors and exogenous variables.

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Imprinted gene Zinc finger protein 127 is a novel regulator of master pluripotency transcription factor, Oct4

  • Kwon, Yoo-Wook;Ahn, Hyo-Suk;Park, Joo-Young;Yang, Han-Mo;Cho, Hyun-Jai;Kim, Hyo-Soo
    • BMB Reports
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    • 제51권5호
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    • pp.242-248
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    • 2018
  • Induced pluripotent stem cells (iPSCs) show great promise for replacing current stem cell therapies in the field of regenerative medicine. However, the original method for cellular reprogramming, involving four exogenous transcription factors, is characterized by low efficiency. Here, we focused on using epigenetic modifications to enhance the reprogramming efficiency. We hypothesized that there would be a new reprogramming factor involved in DNA demethylation, acting on the promoters of pluripotency-related genes. We screened proteins that bind to the methylated promoter of Oct4 and identified Zinc finger protein 127 (Zfp127), the functions of which have not yet been identified. We found that Zfp127 binds to the Oct4 promoter. Overexpression of Zfp127 in fibroblasts induced demethylation of the Oct4 promoter, thus enhancing Oct4 promoter activity and gene expression. These results demonstrate that Zfp127 is a novel regulator of Oct4, and may become a potent target to improve cellular reprogramming.