590 research outputs found

    Organic flexible memristor with reduced operating voltage and high stability by interfacial control of conductive filament growth

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    This work was supported in part through the BK21 Program funded by Ministry of Education of Korea.Herein, the underlying mechanisms for the growth of conductive filaments (CFs) at a metal–polymer electrolyte interface through ion migration in organic electrochemical metallization (ECM) memristor are presented. It is observed that the free volume of voids (nanopores) in the polymer electrolyte serves as the pathways of metal‐cations whereas the interfacial topography between an active electrode and a polymer electrolyte determines the nucleation sites of the CFs. The growth kinetics of the CFs and the resultant resistive memory are found to vary with the molecular weight of the polymer electrolyte and the metal protrusions at the interface. Our direct observations show that the free volume of voids of the polymer electrolyte, varied with the molecular weight, dictates the ion transport for the growth and the disruption of the CFs. Our organic ECM‐based memristor with a hetero‐electrolyte exhibits high mechanical flexibility, low switching voltages reduced by about three times compared to those of conventional devices, and stable memory retention for longer than 104 s under repeated cycles of bending.PostprintPeer reviewe

    Identification of microRNA precursors in Bruguiera spp.

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    MicroRNAs (miRNA) are approximately 22 nt single stranded functional RNAs derived from long stem-loop precursors transcribed by RNA polymerase II. They regulate gene expression through post-transcriptional gene silencing and are important for the regulation of growth, development and stress responses in plants. Mature nucleotide sequences of many miRNA families are highly conserved across the plant kingdom and can be used to identify and annotate homologs and potential miRNA targets. In this study, mature miRNA sequences retrieved from the miRNA registry (miRBase) were used to identify precursor sequences of miRNA orthologs and their potential targets among Expressed Sequence Tags (ESTs) of the mangrove species Bruguiera cylindrica (L.) Blume, B. gymnorhiza (L.) Lam. and B. sexangula (Lour.) Poir. Candidate miRNA precursors, which potentially belong to the miR156/7, miR396 and miR529 families, had high sequence identity between Bruguiera cylindrica and Bruguiera gymnorhiza, and expression of RNA was confirmed in both species. A number of candidate targets for miR396 and miR529 were also identified among EST from B. gymnorhiza

    Reconstituting ring-rafts in bud-mimicking topography of model membranes.

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    During vesicular trafficking and release of enveloped viruses, the budding and fission processes dynamically remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud topography in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the dynamic membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud topography in the sorting and migration machinery of key signalling proteins involved in membrane budding

    Abalone visceral extract inhibit tumor growth and metastasis by modulating Cox-2 levels and CD8+ T cell activity

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    <p>Abstract</p> <p>Background</p> <p>Abalone has long been used as a valuable food source in East Asian countries. Although the nutritional importance of abalone has been reported through <it>in vitro </it>and <it>in vivo </it>studies, there is little evidence about the potential anti-tumor effects of abalone visceral extract. The aim of the present study is to examine anti-tumor efficacy of abalone visceral extract and to elucidate its working mechanism.</p> <p>Methods</p> <p>In the present study, we used breast cancer model using BALB/c mouse-derived 4T1 mammary carcinoma and investigated the effect of abalone visceral extract on tumor development. Inhibitory effect against tumor metastasis was assessed by histopathology of lungs. Cox-2 productions by primary and secondary tumor were measured by real-time RT-PCR and immunoblotting (IB). Proliferation assay based on [<sup>3</sup>H]-thymidine incorporation and measurement of cytokines and effector molecules by RT-PCR were used to confirm tumor suppression efficacy of abalone visceral extract by modulating cytolytic CD8+ T cells. The cytotoxicity of CD8<sup>+ </sup>T cell was compared by JAM test.</p> <p>Results</p> <p>Oral administration of abalone visceral extract reduced tumor growth (tumor volume and weight) and showed reduced metastasis as confirmed by decreased level of splenomegaly (spleen size and weight) and histological analysis of the lung metastasis (gross analysis and histological staining). Reduced expression of Cox-2 (mRNA and protein) from primary tumor and metastasized lung was also detected. In addition, treatment of abalone visceral extract increased anti-tumor activities of CD8<sup>+ </sup>T cells by increasing the proliferation capacity and their cytolytic activity.</p> <p>Conclusions</p> <p>Our results suggest that abalone visceral extract has anti-tumor effects by suppressing tumor growth and lung metastasis through decreasing Cox-2 expression level as well as promoting proliferation and cytolytic function of CD8<sup>+ </sup>T cells.</p

    Single-step genome-wide association study for social genetic effects and direct genetic effects on growth in Landrace pigs

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    In livestock social interactions, social genetic effects (SGE) represent associations between phenotype of one individual and genotype of another. Such associations occur when the trait of interest is affected by transmissible phenotypes of social partners. The aim of this study was to estimate SGE and direct genetic effects (DGE, genetic effects of an individual on its own phenotype) on average daily gain (ADG) in Landrace pigs, and to conduct single-step genome-wide association study using SGE and DGE as dependent variables to identify quantitative trait loci (QTLs) and their positional candidate genes. A total of 1,041 Landrace pigs were genotyped using the Porcine SNP 60K BeadChip. Estimates of the two effects were obtained using an extended animal model. The SGE contributed 16% of the total heritable variation of ADG. The total heritability estimated by the extended animal model including both SGE and DGE was 0.52. The single-step genome-wide association study identified a total of 23 QTL windows for the SGE on ADG distributed across three chromosomes (i.e., SSC1, SSC2, and SSC6). Positional candidate genes within these QTL regions included PRDM13, MAP3K7, CNR1, HTR1E, IL4, IL5, IL13, KIF3A, EFHD2, SLC38A7, mTOR, CNOT1, PLCB2, GABRR1, and GABRR2, which have biological roles in neuropsychiatric processes. The results of biological pathway and gene network analyses also support the association of the neuropsychiatric processes with SGE on ADG in pigs. Additionally, a total of 11 QTL windows for DGE on ADG in SSC2, 3, 6, 9, 10, 12, 14, 16, and 17 were detected with positional candidate genes such as ARL15. We found a putative pleotropic QTL for both SGE and DGE on ADG on SSC6. Our results in this study provide important insights that can help facilitate a better understanding of the molecular basis of SGE for socially affected traits.info:eu-repo/semantics/publishedVersio
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