• 제목/요약/키워드: Key factor

검색결과 3,476건 처리시간 0.037초

Monte Carlo simulation of spatial resolution of lens-coupled LYSO scintillator for intense pulsed gamma-ray imaging system with large field of view

  • Guoguang Li;Liang Sheng;Baojun Duan;Yang Li;Dongwei Hei;Qingzi Xing
    • Nuclear Engineering and Technology
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    • 제56권7호
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    • pp.2650-2658
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    • 2024
  • In this paper, we use a Monte Carlo (MC) simulation based on Geant4 to investigate the influence of four parameters on the spatial resolution of the lens-coupled lutetium yttrium orthosilicate (LYSO) scintillator, including the thickness of the LYSO scintillator, the F-number and minification factor of the lens, and the incident position of the gamma-rays. Simulation results show that when the gamma-rays are incident along the lens axis, the smaller the thickness, the larger the F-number, the larger the minification factor, the higher the spatial resolution, with an isotropic point spread function (PSF). As the incident position of the gamma-rays deviates from the lens axis, the spatial resolution decreases, and the PSF becomes anisotropic. In addition, by analyzing the whole physical process of the lens-coupled LYSO scintillator from gamma-rays to secondary electrons to fluorescence photons, we aim to provide a detailed analysis of the influence of each parameter on the spatial resolution. The results show that the PSF of the secondary electrons energy deposition is almost constant in the simulation, which determines the upper limit of the spatial resolution. Meanwhile, the dispersion process of the fluorescence photons can explain the reason why each parameter affects the spatial resolution.

Isolation, Expression Pattern, Polymorphism and Association Analysis of Porcine TIAF1 Gene

  • Wang, Y.;Xiong, Y.Z.;Ren, Z.Q.;Zuo, B.;Lei, M.G.;Deng, C.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권3호
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    • pp.313-318
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    • 2009
  • TIAF1 is a TGF-${\beta}$1-induced anti-apoptotic factor that plays a critical role in blocking TNF (tumor necrosis factor) cytotoxicity in mouse fibroblasts and participates in TGF-${\beta}$-mediated growth regulation. In this study, we obtained the full-length cDNA sequence of the porcine TIAF1 gene. Real-time PCR further revealed that the TIAF1 gene was expressed at the highest level in liver and kidney with prominent expressions detected in uterus, and lower levels detected in heart, spleen, lung, stomach, small intestine, skeletal muscle and fat of Large White pigs. Sequence analysis indicated that a 6 base-pair deletion mutation existed in the exon of the TIAF1 gene between Meishan and Large White pigs. This mutation induced deletion of Gln and Val amino acids. PCR-RFLP was used to detect the polymorphism in 394 pigs of a "Large White${\times}$Meishan" $F_{2}$ resource population and four purebred pig populations. The frequencies of the A allele (with a 6 bp deletion) were dominant in Chinese Meishan and Bamei pigs, and the frequencies of the B allele (no 6 bp deletion) were dominant in Large White and Landrace pigs. Association analyses revealed that the deletion mutation had highly significant associations (p<0.01) with meat marbling score of the thorax-waist longissimus dorsi (LD) muscle (MM1) and intramuscular fat percentage (IMF), and significant associations (p<0.05) with carcass length (CL). The results presented here supply evidence that the 6 bp deletion mutation in the TIAF1 gene affects porcine meat quality and provides useful information for further porcine breeding.

한국 농수산물 수출업체의 무역보험상품 이용에 관한 실증분석 (An Empirical Study on the Use of Trade Insurance by Korea Agricultural and Marine Products Trading Companies)

  • 박명섭;박영현
    • 무역상무연구
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    • 제66권
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    • pp.285-312
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    • 2015
  • Export and import of food, agriculture, forestry, fishery products are suffering from low growth rate due to the European financial crisis, global recession, and Japan's 2012 export expansion following the aftermath of 2011 earthquake. Upon the signing and enactment of Free Trade Agreement with the U.S. and the EU, agriculture and fishery product have become the center of attention. Agriculture and fishery was reported to be 80million dollars, 1.46% of total national export, in 2012. Starting from2000, South Korea's government began its effort to expand agriculture and fishery export and as a result, export has steadily increased despite decreased consumption led by global recession. K-Sure has started an insurance program with the purpose of promoting SME business's export. It protects SME business against risk arising from credit, emergency, bad debt, and domestic price increase. This study aims to evaluate the service quality of K-Sure's insurance program via surveying SME businesses in the agriculture and fishery industry. Also this study will identify key service factors for SME businesses and explore ways to expand SME exports of agriculture and fishery by analyzing consumer satisfaction index. Results indicated service product quality factor, service communication quality factor, and social quality factor was key to improving consumer satisfaction for SME businesses in agriculture and fishery industry. Service product quality factor had a negative effect on consumer satisfaction in term of variety and results indicated that service communication quality factor's responsiveness element had minimal impact on consumer satisfaction. Conversely, all elements for social quality factor had positive effects on consumer satisfaction. Thus, leading to the conclusion that improvements in service product quality factor and service communication quality factor will indeed increase consumer satisfaction.

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Comparison of Piano Key and Rectangular Labyrinth Weir Discharge Efficiency

  • Anh Tuan Le
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.39-39
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    • 2023
  • Nonlinear weirs, such as labyrinth and piano key weirs, are suitable methods to handle increased flood flows that may be expected due to climate change. Although specific physical models are considered to be an effective way of investigating fluid flows, simply conducting physical model tests is insufficient to fully comprehend the hydraulic and discharge characteristics of non-linear weirs. In this study, computational fluid dynamics algorithms have been used extensively to investigate complex flow physics instead of relying on reduced scale models. The discharge capacity of the piano key weir and the rectangular labyrinth weir is compared using a three-dimensional numerical model, which is validated by the available experimental data. The results confirm that piano key weir is more efficient than the rectangular labyrinth weir for a wide range of head water ratios. By analyzing the contribution of discharge over inlet, outlet and sidewall crests, the factor that make the piano key weir superior to the rectangular weir is the sidewall discharge.

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PKHD1 Gene Silencing May Cause Cell Abnormal Proliferation through Modulation of Intracellular Calcium in Autosomal Recessive Polycystic Kidney Disease

  • Yang, Ji-Yun;Zhang, Sizhong;Zhou, Qin;Guo, Hong;Zhang, Ke;Zheng, Rong;Xiao, Cuiying
    • BMB Reports
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    • 제40권4호
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    • pp.467-474
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    • 2007
  • Autosomal recessive polycystic kidney disease (ARPKD) is one of the important genetic disorders in pediatric practice. Mutation of the polycystic kidney and hepatic disease gene 1 (PKHD1) was identified as the cause of ARPKD. The gene encodes a 67-exon transcript for a large protein of 4074 amino acids termed fibrocystin, but its function remains unknown. The neoplastic-like in cystic epithelial proliferation and the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis overactivity are known as the most important characteristics of ARPKD. Since the misregulation of $Ca^{2+}$ signaling may lead to aberrant structure and function of the collecting ducts in kidney of rat with ARPKD, present study aimed to investigate the further mechanisms of abnormal proliferation of cystic cells by inhibition of PKHD1 expression. For this, a stable PKHD1-silenced HEK-293T cell line was established. Then cell proliferation rates, intracellular $Ca^{2+}$ concentration and extracellular signal-regulated kinase 1/2 (ERK1/2) activity were assessed after treatment with EGF, a calcium channel blocker and agonist, verapamil and Bay K8644. It was found that PKHD1-silenced HEK-293T cell lines were hyperproliferative to EGF stimulation. Also PKHD1-silencing lowered the intracellular $Ca^{2+}$ and caused EGF-induced ERK1/2 overactivation in the cells. An increase of intracellular $Ca^{2+}$ in PKHD1-silenced cells repressed the EGF-dependent ERK1/2 activation and the hyperproliferative response to EGF stimulation. Thus, inhibition of PKHD1 can cause EGF-induced excessive proliferation through decreasing intracellular $Ca^{2+}$ resulting in EGF-induced ERK1/2 activation. Our results suggest that the loss of fibrocystin may lead to abnormal proliferation in kidney epithelial cells and cyst formation in ARPKD by modulation of intracellular $Ca^{2+}$.

차세대 컨버전스서비스 핵심불확실성요인 도출에 관한 분석 (Deduction for Key Uncertainty Factors for the Next-generation Convergence Service)

  • 송영화;박선영;이중만
    • 기술혁신학회지
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    • 제12권1호
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    • pp.212-236
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    • 2009
  • 본 연구는 차세대 컨버전스서비스를 대상으로 고객, 기술, 사업자, 규제의 4대 이슈별로 환경 불확실성요인을 규명하고, 이들 환경 불확실성요인 중 특히 핵심이 되는 불확실성 요인을 도출하였다. 이어 도출된 핵심불확실성요인(KUF: Key Uncertainty Factor)을 중심으로 환경의 잔여불확실성 수준에 대한 평가를 시나리오 플래닝에 의해 실시하고, 이를 기반으로 차세대 컨버전스서비스의 진입전략 수립을 위한 방향을 제시하였다. 본 연구의 차세대 컨버전스서비스 사업의 불확실성 평가 및 진입 시나리오 구성에 대한 연구결과를 종합하면 다음과 같다. 2가지 잔여 불확실성 수준(선택 가능한 미래 수준, 예측 범위의 미래 수준)의 6개 시나리오를 대상으로 각각의 전략적 속성을 평가한 결과 시장 진입의 성공 요소로 2가지 핵심성공요인(KSF: Key Success Factor)을 도출하였다. 즉, 고객수요추세, 광고규제 완화를 핵심성공요인(KSF: Key Success Factor)으로 도출하였으며, 이를 토대로 4가지 전략적 시나리오 유형 및 각 시나리오 별 요구되는 사업자 대응역량에 대한 방향성을 제시하였다. 본 연구의 결과는 컨버전스 시장의 활성화는 물론 관련 사업자의 자원의 효율적 배분, 진입형태, 진입 적정시기 등 진입전략 수립에 많은 시사점을 제공할 것이다.

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Isolation and identification of goose skeletal muscle satellite cells and preliminary study on the function of C1q and tumor necrosis factor-related protein 3 gene

  • Wang, Han;He, Ke;Zeng, Xuehua;Zhou, Xiaolong;Yan, Feifei;Yang, Songbai;Zhao, Ayong
    • Animal Bioscience
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    • 제34권6호
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    • pp.1078-1087
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    • 2021
  • Objective: Skeletal muscle satellite cells (SMSCs) are significant for the growth, regeneration, and maintenance of skeletal muscle after birth. However, currently, few studies have been performed on the isolation, culture and inducing differentiation of goose muscle satellite cells. Previous studies have shown that C1q and tumor necrosis factor-related protein 3 (CTRP3) participated in the process of muscle growth and development, but its role in the goose skeletal muscle development is not yet clear. This study aimed to isolate, culture, and identify the goose SMSCs in vitro. Additionally, to explore the function of CTRP3 in goose SMSCs. Methods: Goose SMSCs were isolated using 0.25% trypsin from leg muscle (LM) of 15 to 20 day fertilized goose eggs. Cell differentiation was induced by transferring the cells to differentiation medium with 2% horse serum and 1% penicillin streptomycin. Immunofluorescence staining of Desmin and Pax7 was used to identify goose SMSCs. Quantitative realtime polymerase chain reaction and western blot were applied to explore developmental expression profile of CTRP3 in LM and the regulation of CTRP3 on myosin heavy chains (MyHC), myogenin (MyoG) expression and Notch signaling pathway related genes expression. Results: The goose SMSCs were successfully isolated and cultured. The expression of Pax7 and Desmin were observed in the isolated cells. The expression of CTRP3 decreased significantly during leg muscle development. Overexpression of CTRP3 could enhance the expression of two myogenic differentiation marker genes, MyHC and MyoG. But knockdown of CTRP3 suppressed their expression. Furthermore, CTRP3 could repress the mRNA level of Notch signaling pathway-related genes, notch receptor 1, notch receptor 2 and hairy/enhancer-of-split related with YRPW motif 1, which previously showed a negative regulation in myoblast differentiation. Conclusion: These findings provide a useful cell model for the future research on goose muscle development and suggest that CTRP3 may play an essential role in skeletal muscle growth of goose.