47 research outputs found

    A Novel Grafting of Polymers onto the Surface of Graphene Oxide

    Get PDF
    A simple grafting of polymers onto graphene oxide (GO) was achieved by polymer radical trapping, ligand-exchange reaction, and surface initiated cationic and anionic graft polymerization. Grafting of poly(ethylene glycol) (PEG) onto GO was successfully achieved by trapping of PEG radicals formed by thermal decomposition of PEG macroazo initiator to give PEG-grafted GO. The grafting of copolymers containing vinyl ferrocene moieties onto GO surfaces was also successfully achieved by the ligand-exchange reaction between ferrocene moieties of these copolymers and GO. Carboxyl groups on GO have an ability to initiate the cationic polymerizations of vinyl monomers, such as N-vinylcarbazole and isobutyl vinyl ether. The corresponding vinyl polymers were grafted onto GO, during the cationic polymerization, based on the termination of growing polymer cation by counter anion (carboxylate) groups on GO. It was found that the anionic ring-opening alternating copolymerization of epoxides with cyclic acid anhydrides was successfully initiated by potassium carboxylate groups on GO, introduced by neutralization of carboxyl groups with KOH, to give the corresponding polyester-grafted GO. The dispersibility of GO in organic solvents was remarkably improved by the grafting of the above polymers onto GO. In addition, easy preparation of reduced GO-based conducting polyaniline composite organogel will be discussed

    Lens and Retina Formation Require Expression of Pitx3 in Xenopus Pre-lens Ectoderm

    Get PDF
    Pitx3 is expressed in tissues fated to contribute to eye development, namely, neurula stage ectoderm and prechordal mesoderm, then presumptive lens ectoderm, placode, and finally lens. Pitx3 overexpression alters lens, optic cup, optic nerve, and diencephalon development. Many of the induced anomalies are attributable to midline deficits; however, as assessed by molecular markers, ectopic Pitx3 appears to temporarily enlarge the lens field. These changes are usually insufficient to generate either ectopic lenses to enlarge the eye that eventually differentiates. Conversely, use of a repressor chimera or of antisense morpholinos alters early expression of marker genes, and later inhibits lens development, thereby abrogating retinal induction. Reciprocal grafting experiments using wild-type and morpholino-treated tissues demonstrate that Pitx3 expression in the presumptive lens ectoderm is required for lens formation. Contradictory to recent assertions that retina can form in the absence of a lens, the expression of Pitx3 in the presumptive lens ectoderm. is critical for retina development

    CK-2 of rainbow trout (Oncorhynchus mykiss) has two differentially regulated alleles that encode a functional chemokine

    Get PDF
    The final publication is available at Elsevier via https://doi.org/10.1016/j.vetimm.2018.02.003. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Rainbow trout chemokine 2 (CK-2) is currently the only known CC chemokine to have a mucin stalk. Further analysis of the mucin stalk region revealed a second, related CC chemokine sequence, denoted here as CK-2.1. This second sequence was determined to be an allele of CK-2 following genomic PCR analysis on several outbred individuals. Furthermore, in both in vivo and in vitro trials, CK-2 and CK-2.1 were both present, but appeared to have differential tissue expression in both control and PHA stimulated samples. Upon the development of a polyclonal antibody to rCK-2, CK-2 was only observed in the brain, liver and head kidney of PHA stimulated rainbow trout tissues. In comparison, when using the rainbow trout monocyte/macrophage-like cell line, RTS-11, CK-2 protein was observed in both control and PHA stimulated conditions. When studying the function of CK-2, a chemotaxis assay revealed that both peripheral blood leukocytes and RTS-11 cells migrated towards rCK-2 significantly at all concentrations studied when compared to truncated β2m. Interestingly, this migration was lowest at both the highest concentration and the lowest concentrations of CK-2. Thus, teleostean chemokine receptors may become desensitized when overstimulated as has been observed in mammalian models. The observed chemotactic function was indeed due to rCK-2 as cell migration was inhibited through pre-treatment of both the cells and the polyclonal antibody with rCK-2. As has been observed thus far with all other chemokines, CK-2 does appear to function through binding to a G-coupled protein receptor as chemotaxis could be inhibited through pre-treatment with pertussis toxin. Overall, the results of this study indicate that CK-2 is a functional chemokine that is encoded by two differentially expressed alleles in rainbow trout, CK-2 and CK-2.1.Natural Sciences and Engineering Research Council || 21752

    Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

    Get PDF
    We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

    Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

    Get PDF
    We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

    Mating Behavior Increases Workload of the Heart in Thoroughbred Stallions

    No full text

    Molecular cloning and characterisation of a carp (Cyprinus carpio) cytokine-like cDNA that shares sequence similarity with IL-6 subfamily cytokines CNTF, OSM and LIF

    No full text
    In the course of suppression subtractive hybridisation between sodium alginate-induced peritoneal cells (SA-PC) and normal head kidney cDNAs in common carp (Cyprinus carpio), a cytokine-like cDNA clone was found. The clone, named M17, contains a 1600 bp nucleotide sequence that encodes a 215 amino acid putative protein that would have a pI of 9.01 and would include a 33 amino acid signal peptide. The 3' untranslated region has seven ATTTA mRNA destabilising motifs that are common in cytokines and oncogenes. In a BLASTP search, M17 was most similar to chicken ciliary neurotrophic factor (CNTF) with 25% amino acid identity, followed by mammalian CNTF, cardiotrophin-1 and leukemia inhibitory factor (LIF) all of which belong to the IL-6 subfamily. However, M17 has some differences with CNTF in that CNTF has no signal sequence, the gene organisation of M17 is three exons and two introns, whereas that of CNTF is two exons and one intron, M17 has seven cysteines while CNTF has one cysteine, and M17 mRNA is detected in peripheral blood leukocytes as well as brain, whereas CNTF is expressed only in the nervous system. Compared to other members in the IL-6 subfamily cytokines, M17's cysteine positions and gene organisation are similar to those of oncostatin M and LIF, although amino acid identities are only 15-17%. Southern hybridisation suggested that M17 is a single copy gene. SA-PC showed significantly higher M17 mRNA levels than normal head kidney cells, which are considered to be a source of the SA-PC, indicating that M17 is inducible by inflammatory stimulation
    corecore