502 research outputs found

    OASIS: Online Application for the Survival Analysis of Lifespan Assays Performed in Aging Research

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    Aging is a fundamental biological process. Characterization of genetic and environmental factors that influence lifespan is a crucial step toward understanding the mechanisms of aging at the organism level. To capture the different effects of genetic and environmental factors on lifespan, appropriate statistical analyses are needed.We developed an online application for survival analysis (OASIS) that helps conduct various novel statistical tasks involved in analyzing survival data in a user-friendly manner. OASIS provides standard survival analysis results including Kaplan-Meier estimates and mean/median survival time by taking censored survival data. OASIS also provides various statistical tests including comparison of mean survival time, overall survival curve, and survival rate at specific time point. To visualize survival data, OASIS generates survival and log cumulative hazard plots that enable researchers to easily interpret their experimental results. Furthermore, we provide statistical methods that can analyze variances among survival datasets. In addition, users can analyze proportional effects of risk factors on survival.OASIS provides a platform that is essential to facilitate efficient statistical analyses of survival data in the field of aging research. Web application and a detailed description of algorithms are accessible from http://sbi.postech.ac.kr/oasis

    REGNET: Mining context-specific human transcription networks using composite genomic information

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    Background: Genome-wide expression profiles reflect the transcriptional networks specific to the given cell context. However, most statistical models try to estimate the average connectivity of the networks from a collection of gene expression data, and are unable to characterize the context-specific transcriptional regulations. We propose an approach for mining context-specific transcription networks from a large collection of gene expression fold-change profiles and composite gene-set information.Results: Using a composite gene-set analysis method, we combine the information of transcription factor binding sites, Gene Ontology or pathway gene sets and gene expression fold-change profiles for a variety of cell conditions. We then collected all the significant patterns and constructed a database of context-specific transcription networks for human (REGNET). As a result, context-specific roles of transcription factors as well as their functional targets are readily explored. To validate the approach, nine predicted targets of E2F1 in HeLa cells were tested using chromatin immunoprecipitation assay. Among them, five (Gadd45b, Dusp6, Mll5, Bmp2 and E2f3) were successfully bound by E2F1. c-JUN and the EMT transcription networks were also validated from literature.Conclusions: REGNET is a useful tool for exploring the ternary relationships among the transcription factors, their functional targets and the corresponding cell conditions. It is able to provide useful clues for novel cell-specific transcriptional regulations. The REGNET database is available at http://mgrc.kribb.re.kr/regnet.open0

    Highly efficient and robust noble-metal free bifunctional water electrolysis catalyst achieved via complementary charge transfer

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    The operating principle of conventional water electrolysis using heterogenous catalysts has been primarily focused on the unidirectional charge transfer within the heterostructure. Herein, multidirectional charge transfer concept has been adopted within heterostructured catalysts to develop an efficient and robust bifunctional water electrolysis catalyst, which comprises perovskite oxides (La0.5Sr0.5CoO3-delta, LSC) and potassium ion-bonded MoSe2 (K-MoSe2). The complementary charge transfer from LSC and K to MoSe2 endows MoSe2 with the electron-rich surface and increased electrical conductivity, which improves the hydrogen evolution reaction (HER) kinetics. Excellent oxygen evolution reaction (OER) kinetics of LSC/K-MoSe2 is also achieved, surpassing that of the noble metal (IrO2), attributed to the enhanced adsorption capability of surface-based oxygen intermediates of the heterostructure. Consequently, the water electrolysis efficiency of LSC/K-MoSe2 exceeds the performance of the state-of-the-art Pt/C||IrO2 couple. Furthermore, LSC/K-MoSe2 exhibits remarkable chronopotentiometric stability over 2,500h under a high current density of 100mAcm(-2). While water electrolysis offers a renewable means to obtain H-2, it is necessary to understand the roles adopted by catalytic components. Here, authors explore a heterostructured MoSe2/perovskite oxide catalyst that shows multidirectional charge transfer to boost electrocatalytic water splitting

    Efficient Photoelectrochemical Water Oxidation by Metal-Doped Bismuth Vanadate Photoanode with Iron Oxyhydroxide Electrocatalyst

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    Intensive attention has been currently focused on the discovery of semiconductor and proficient cocatalysts for eventual applications to the photoelectrochemical water splitting system. A W-Mo-doped BiVO4 semiconductor was prepared by the surfactant-assisted thermal decomposition method on a fluorine-doped tin oxide conductive film. The W-Mo-doped BiVO4 films showed a porous morphology with the grain sizes of about 270 nm. Because the hole diffusion length of BiVO4 is about 100 nm, the W-Mo-doped BiVO4 film in this study is an ideal candidate for the photoelectrochemical water oxidation. Iron oxyhydroxide (FeOOH) electrocatalyst was chemically deposited on the W-Mo-doped BiVO4 to investigate the effect of the electrocatalyst on the semiconductor. The W-Mo-doped BiVO4/FeOOH composite electrode showed enhanced activity compared to the pristine W-Mo-doped BiVO4 electrode for water oxidation reaction. The chemical deposition is a promising method for the deposition of FeOOH on semiconductor

    Imaging Findings of Castleman's Disease Localized in the Axilla: A Case Report

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    Castleman's disease is a rare benign lymphoproliferative disorder of uncertain origin which most commonly involves the mediastinum but rarely affects the axilla. We report a case of localized Castleman's disease involving the axillary lymph node. Mammography revealed a well-defined, homogeneously dense ovoid mass, 3 cm in size, in the left axilla, while gray-scale ultrasonography (US) demonstrated a well-defined, uniformly hypoechoic ovoid mass with good through transmission. Peripheral hypervascularity was observed at power Dopper US, and early rapid homogeneous enhancement at contrast-enhanced dynamic CT

    Replacing conventional battery electrolyte additives with dioxolone derivatives for high-energy-density lithium-ion batteries

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    Solid electrolyte interphases generated using electrolyte additives are key for anode-electrolyte interactions and for enhancing the lithium-ion battery lifespan. Classical solid electrolyte interphase additives, such as vinylene carbonate and fluoroethylene carbonate, have limited potential for simultaneously achieving a long lifespan and fast chargeability in high-energy-density lithium-ion batteries (LIBs). Here we report a next-generation synthetic additive approach that allows to form a highly stable electrode-electrolyte interface architecture from fluorinated and silylated electrolyte additives; it endures the lithiation-induced volume expansion of Si-embedded anodes and provides ion channels for facile Li-ion transport while protecting the Ni-rich LiNi0.8Co0.1Mn0.1O2 cathodes. The retrosynthetically designed solid electrolyte interphase-forming additives, 5-methyl-4-((trifluoromethoxy)methyl)-1,3-dioxol-2-one and 5-methyl-4-((trimethylsilyloxy)methyl)-1,3-dioxol-2-one, provide spatial flexibility to the vinylene carbonate-derived solid electrolyte interphase via polymeric propagation with the vinyl group of vinylene carbonate. The interface architecture from the synthesized vinylene carbonate-type additive enables high-energy-density LIBs with 81.5% capacity retention after 400 cycles at 1???C and fast charging capability (1.9% capacity fading after 100 cycles at 3???C)

    De Novo Design and Synthesis of Ultra-Short Peptidomimetic Antibiotics Having Dual Antimicrobial and Anti-Inflammatory Activities

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    Ravichandran N. Murugan, Mija Ahn, Eunha Hwang, Ji-Hyung Seo, Chaejoon Cheong, Jeong Kyu Bang, Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, Republic of KoreaBinu Jacob, Song Yub Shin, Department of Bio-Materials, Graduate School and Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, Republic of KoreaHoik Sohn, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, United States of AmericaHyo-Nam Park, Jae-Kyung Hyun, Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon, Republic of KoreaEunjung Lee, Ki-Woong Jeong, Yangmee Kim, Department of Bioscience and Biotechnology, Institute of SMART Biotechnology, Konkuk University, Seoul, Republic of KoreaKy-Youb Nam, Bioinformatics and Molecular Design Research Center, Yonsei University Research Complex, Seoul, Republic of KoreaBackground: Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability.-- Methodology/Principal Findings: In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(π)- and N(τ)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti–methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes. -- Conclusion/Significance: The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics.This work was supported in part by the Korea Basic Science Institute's research program grants T33418 (J.K.B) and T33518 (J-k.H.), and the Korea Research Foundation, funded by the Korean Government (KRF-2011-0009039 to S.Y.S.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.ChemistryBiochemistryEmail: [email protected] (JKB)Email: [email protected] (SYS
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