• Title/Summary/Keyword: host factor

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Novel host and electron blocking materials for efficient and long lifetime phosphorescent OLEDs

  • Vestweber, Horst;Gerhard, Anja;Kaiser, Joachim;Heil, Holger;Kroeber, Jonas;Pflumm, Christof;Stoessel, Philipp;Joosten, Dominik;Buesing, Arne;Fortte, Rocco;Parham, Amir;Boehm, Edgar
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.925-927
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    • 2008
  • In order to improve the performance in green phosphorescent OLED devices, Merck has developed novel host and electron blocking materials. The newly developed host materials improve the device lifetime by a factor of 3. The newly developed electron blocking materials having not only electron but also exciton barrier properties increase the efficiency of the device by a factor of 1.4. Comparable results were achieved in phosphorescent red systems with further host materials.

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The Effects of Financial Development on Foreign Direct Investment (금융 발전이 외국인직접투자에 미치는 영향에 대한 분석)

  • Jung-Whan Cho;Tae-Hwang Kim
    • Korea Trade Review
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    • v.45 no.4
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    • pp.195-205
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    • 2020
  • This study investigates the effects of financial development on the foreign direct investment (FDI) flow in host countries. Using bilateral FDI data from 34 OECD source countries to 146 host countries, we performed panel data analysis based on a gravity FDI equation. We hypothesized that the financial development would increase the volume of FDI flows. The results suggest that the well-functioning finance market of source countries as well as a better accessable financial market of host countries contribute to the increase in FDI of OECD in their partner countries. We found also that the financial development effects of source countries are larger than those of host countries. This result shows that the financial development can play a crucial role to impact the FDI inflows as push factor in source country than as a pull factor in host countries.

Structure and Function of the Influenza A Virus Non-Structural Protein 1

  • Han, Chang Woo;Jeong, Mi Suk;Jang, Se Bok
    • Journal of Microbiology and Biotechnology
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    • v.29 no.8
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    • pp.1184-1192
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    • 2019
  • The influenza A virus is a highly infectious respiratory pathogen that sickens many people with respiratory disease annually. To prevent outbreaks of this viral infection, an understanding of the characteristics of virus-host interaction and development of an anti-viral agent is urgently needed. The influenza A virus can infect mammalian species including humans, pigs, horses and seals. Furthermore, this virus can switch hosts and form a novel lineage. This so-called zoonotic infection provides an opportunity for virus adaptation to the new host and leads to pandemics. Most influenza A viruses express proteins that antagonize the antiviral defense of the host cell. The non-structural protein 1 (NS1) of the influenza A virus is the most important viral regulatory factor controlling cellular processes to modulate host cell gene expression and double-stranded RNA (dsRNA)-mediated antiviral response. This review focuses on the influenza A virus NS1 protein and outlines current issues including the life cycle of the influenza A virus, structural characterization of the influenza A virus NS1, interaction between NS1 and host immune response factor, and design of inhibitors resistant to the influenza A virus.

A study on the difference in the safety culture cognition of host company and subcontractor (주관기업과 협력기업의 안전문화 인식 차이에 관한 연구)

  • Choi, Byung-Gil;Yoon, Seok-Joon;Choi, Seo-Yeon;Moon, Kyoung-Whan
    • Journal of the Korea Safety Management & Science
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    • v.17 no.3
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    • pp.173-183
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    • 2015
  • The study conducted questionnaire analysis on 607 host company employee and 404 subcontractor employee in order to examine the difference in the safety culture cognition of host company and subcontractor. As a result, host company had higher recognition in all safety culture factors compare to that of subcontractor, and there were bigger gap of cognition in the 'cognition in safety status and culture', 'accident and near-miss', 'immediate superior's concentration degree in safety and health' than that of other cognition factors. Furthermore, team leaders showed the highest cognition in both host company and subcontractor, and employees with above 20 year career had the highest cognition in both host company and subcontractor. There is high relationship between host company and subcontractor in the correlations in safety culture cognition factors. Through this study, we identified the difference in the safety culture cognition factor of host company and subcontractor.

Virus-induced Silencing of the WRKY1 Transcription Factor that Interacts with the SL1 Structure of Potato virus X Leads to Higher Viral RNA Accumulation and Severe Necrotic Symptoms

  • Park, Sang-Ho;Kim, Kook-Hyung
    • The Plant Pathology Journal
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    • v.28 no.1
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    • pp.40-48
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    • 2012
  • $Potato$ $virus$ $X$ (PVX) replication is precisely regulated by regulatory viral sequences and by viral and/or host proteins. In a previous study, we identified a 54-kDa cellular tobacco protein that bound to a region within the first 46 nucleotides (nt) of the 5' non-translated region (NTR) of the viral genome. Optimal binding was dependent upon the presence of an ACCA sequence at nt 10-13. To identify host factors that bind to 5' NTR elements including AC-rich sequences as well as stemloop 1 (SL1), we used northwestern blotting and matrixassisted laser desorption/ionization time-of-flight mass spectrometry for peptide mass fingerprinting. We screened several host factors that might affect PVX replication and selected a candidate protein, $Nicotiana$ $tabacum$ WRKY transcription factor 1 (NtWRKY1). We used a $Tobacco$ $rattle$ $virus$ (TRV)-based virus-induced gene silencing (VIGS) system to investigate the role of NtWRKY1 in PVX replication. Silencing of $WRKY1$ in $Nicotiana$ $benthamiana$ caused lethal apical necrosis and allowed an increase in PVX RNA accumulation. This result could reflect the balancing of PVX accumulation in a systemic $N.$ $benthamiana$ host to maintain PVX survival and still produce a suitable appearance of mosaic and mottle symptoms. Our results suggest that PVX may recruit the WRKY transcription factor, which binds to the 5' NTR of viral genomic RNA and acts as a key regulator of viral infection.

Bcl-2 Knockdown Accelerates T Cell Receptor-Triggered Activation-Induced Cell Death in Jurkat T Cells

  • Lee, Yun-Jung;Won, Tae Joon;Hyung, Kyeong Eun;Lee, Mi Ji;Moon, Young-Hye;Lee, Ik Hee;Go, Byung Sung;Hwang, Kwang Woo
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.1
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    • pp.73-78
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    • 2014
  • Cell death and survival are tightly controlled through the highly coordinated activation/inhibition of diverse signal transduction pathways to insure normal development and physiology. Imbalance between cell death and survival often leads to autoimmune diseases and cancer. Death receptors sense extracellular signals to induce caspase-mediated apoptosis. Acting upstream of CED-3 family proteases, such as caspase-3, Bcl-2 prevents apoptosis. Using short hairpin RNAs (shRNAs), we suppressed Bcl-2 expression in Jurkat T cells, and this increased TCR-triggered AICD and enhanced TNFR gene expression. Also, knockdown of Bcl-2 in Jurkat T cells suppressed the gene expression of FLIP, TNF receptor-associated factors 3 (TRAF3) and TRAF4. Furthermore, suppressed Bcl-2 expression increased caspase-3 and diminished nuclear factor kappa B (NF-${\kappa}B$) translocation.

Cosmological Origin of Satellites around Isolated Dwarf Galaxies

  • Chun, Kyungwon;Shin, Jihye;Smith, Rory;Kim, Sungsoo S.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.39.1-39.1
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    • 2019
  • We trace the cosmological origin of satellites around isolated dwarf galaxies using a very high resolution (12 pc/h) cosmological hydrodynamic zoom simulation. To realistically describe the formation and evolution of small-mass stellar satellites, our model includes a full baryonic physics treatment. We find that the mini-halos form objects resembling dwarf galaxies. The majority of their star forming gas is accreted after reionization, thus the survival of a mini-halo's gas to reionization is not an important factor. Instead, the key factor seems to be the ability for a mini-halo to cool its recently accreted gas, which is more efficient in more massive halos. Although the host galaxy is only a dwarf galaxy itself, we find that ram pressure is an efficient means by which accreted mini-halos lose their gas content, both by interacting with hot halo gas but also in direct collisions with the gas disk of the host. The satellites are also disrupted by the tidal forces near the center of the host galaxy. Compared to the disrupted satellites, surviving satellites are relatively more massive, but tend to infall later into the host galaxy, thus reducing the time they are subjected to destructive environmental mechanisms and dynamical friction.

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Optimizing Garbage Collection Overhead of Host-level Flash Translation Layer for Journaling Filesystems

  • Son, Sehee;Ahn, Sungyong
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.27-35
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    • 2021
  • NAND flash memory-based SSD needs an internal software, Flash Translation Layer(FTL) to provide traditional block device interface to the host because of its physical constraints, such as erase-before-write and large erase block. However, because useful host-side information cannot be delivered to FTL through the narrow block device interface, SSDs suffer from a variety of problems such as increasing garbage collection overhead, large tail-latency, and unpredictable I/O latency. Otherwise, the new type of SSD, open-channel SSD exposes the internal structure of SSD to the host so that underlying NAND flash memory can be managed directly by the host-level FTL. Especially, I/O data classification by using host-side information can achieve the reduction of garbage collection overhead. In this paper, we propose a new scheme to reduce garbage collection overhead of open-channel SSD by separating the journal from other file data for the journaling filesystem. Because journal has different lifespan with other file data, the Write Amplification Factor (WAF) caused by garbage collection can be reduced. The proposed scheme is implemented by modifying the host-level FTL of Linux and evaluated with both Fio and Filebench. According to the experiment results, the proposed scheme improves I/O performance by 46%~50% while reducing the WAF of open-channel SSDs by more than 33% compared to the previous one.

The Importance of Host Factors for the Replication of Plant RNA Viruses (식물 바이러스 증식에 관여하는 기주 요인의 중요성)

  • Park Mi-Ri;Kim Kook-Hyung
    • Research in Plant Disease
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    • v.11 no.2
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    • pp.98-105
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    • 2005
  • All viruses have few genes relative to their hosts. Viruses, thus, utilize many host factors for efficient viral replication in host cell. Virus-host interactions are crucial determinations of host range, replication, and pathology. Host factors participate in most steps of positive-strand RNA virus infection, including entry, viral gene expression, virion assembly, and release. Recent data show that host factors play important roles in assembling the viral RNA replication complex, selecting and recruiting viral RNA replication templates, activating the viral complex for RNA synthesis, and the other steps. These virus-host interactions may contribute to the host specificity and/or pathology. Positive-strand RNA viruses encompass over two-thirds of all virus genera and include numerous pathogens. This review focuses on the importance of host factors involved in positive strand plant RNA virus genome replication.

Host Cell Nuclear Localization of Shigella flexneri Effector OspF Is Facilitated by SUMOylation

  • Jo, Kyungmin;Kim, Eun Jin;Yu, Hyun Jin;Yun, Cheol-Heui;Kim, Dong Wook
    • Journal of Microbiology and Biotechnology
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    • v.27 no.3
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    • pp.610-615
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    • 2017
  • When Shigella infect host cells, various effecter molecules are delivered into the cytoplasm of the host cell through the type III secretion system (TTSS) to facilitate their invasion process and control the host immune responses. Among these effectors, the S. flexneri effector OspF dephosphorylates mitogen-activated protein kinases and translocates itself to the nucleus, thus preventing histone H3 modification to regulate expression of proinflammatory cytokines. Despite the critical role of OspF, the mechanism by which it localizes in the nucleus has remained to be elucidated. In the present study, we identified a potential small ubiquitin-related modifier (SUMO) modification site within OspF and we demonstrated that Shigella TTSS effector OspF is conjugated with SUMO in the host cell and this modification mediates the nuclear translocation of OspF. Our results show a bacterial virulence factor can exploit host post-translational machinery to execute its intracellular trafficking.