72 resultados para Covalent anchorage


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Wave impacts on an Oscillating Wave Surge Converter are examined using experimental and numerical methods. The mechanics of the impact event are identified experimentally with the use of images recorded with a high speed camera. It is shown that it is the device which impacts the wave rather than a breaking wave impacting the device. Numerical simulations using two different approaches are used to further understand the issue. Good agreement is shown between numerical simulations and experimental measurements at 25th scale.

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Photoresponsive oligonucleotides (ONs) incorporating isoxazole-linked azobenzene (AB) moieties were prepared by resin-supported nitrile oxide-alkyne cycloaddition (NOAC) chemistry. The thermal and photochromic properties of the modified ONs were significantly influenced by the extent of pi-conjugation between the isoxazole and the AB modules.

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As the potassium fractional coverage of a cobalt {1010BAR} surface is increased over the range 0.2 to 0.6 monolayer the adlayer passes through a series of phase transitions. A commensurate phase is formed at exactly 0.5 monolayer, and corresponds to adatoms bonded in high-symmetry hollow sites on the unreconstructed cobalt surface, with an effective adatom radius lying between the ionic and covalent radii of potassium. A detailed structural study shows that the structural transitions can be characterised within a one-dimensional Frenkel-Kontorova model, with small lateral displacements of adatoms away from hollow sites in the low and high coverage phases. The low coverage phases progress from a distributed vacancy structure to a low density domain-wall structure; while the high coverage phase formed above half a monolayer is a high density asymmetric domain-wall structure.

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The surface structure of the clean Co{1010BAR} surface and a c(2 x 2) potassium overlayer have been determined by quantitative low energy electron diffraction. The Co{1010BAR} sample has been shown to be laterally unreconstructed with the surface being uniquely terminated by an outermost closely packed double layer (dz12 = 0.68 angstrom). A damped oscillatory relaxation of the outermost three atomic layers occurs, with relaxations DELTA-dz12 = -6.5 +/- 2% and DELTA-dz23 = +1.0 +/- 2%.

The c(2 x 2) overlayer formed at a coverage of 0.5 ML was subjected to a full I-V analysis. A range of adsorption sites were tested including fourfold hollow, on-top, and both long and short bridge sites in combination with both "long" and "short" cobalt interlayer terminations. A clear preference was found for adsorption in the maximal coordination fourfold hollow site. No switching of surface termination occurs. The potassium adatoms reside in the [1210BAR] surface channels directly above second layer cobalt atoms with a potassium to outermost cobalt interlayer separation of 2.44 +/- 0.05 angstrom. Potassium-cobalt bond lengths of 3.40 +/- 0.05 and 3.12 +/- 0.05 angstrom between the four (one) outermost (second) layer nearest-neighbour substrate atoms suggests a potassium effective radius of 1.87 +/- 0.05 angstrom, somewhat smaller than the Pauling covalent radius and considerably larger than the ionic radius (1.38 angstrom). The alkali-surface bonding is thus predominantly "covalent"/"metallic".

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We designed a straightforward biotinylated probe using the N-terminal substrate-like region of the inhibitory site of human cystatin C as a scaffold, linked to the thiol-specific reagent diazomethylketone group as a covalent warhead (i.e. Biot-(PEG)2-Ahx-LeuValGly-DMK). The irreversible activity-based probe bound readily to cysteine cathepsins B, L, S and K. Moreover affinity labeling is sensitive since active cathepsins were detected in the nM range using an ExtrAvidin®-peroxidase conjugate for disclosure. Biot-(PEG)2-Ahx-LeuValGly-DMK allowed a slightly more pronounced labeling for cathepsin S with a compelling second-order rate constant for association (kass = 2,320,000 M−1 s−1). Labeling of the active site is dose-dependent as observed using 6-cyclohexylamine-4-piperazinyl-1,3,5-triazine-2-carbonitrile, as competitive inhibitor of cathepsins. Finally we showed that Biot-(PEG)2-Ahx-LeuValGly-DMK may be a simple and convenient tool to label secreted and intracellular active cathepsins using a myelomonocytic cell line (THP-1 cells) as model.

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Many timber structures may require strengthening due to either decay and aging or an increase of load. This paper presents an experimental study in which eleven timber beams were tested, including three unstrengthened reference beams and eight beams strengthened with NSM CFRP bars. The test parameters include the position of NSM (tensile face or the bottom of the sides), the number of CFRP bars (1 or 2), and additional anchorage of NSM CFRP bars (steel wire U anchors or CFRP U strips). The test results show that the ultimate flexural strength of the timber beams were increased by 14%∼85% with an average of 47% due to NSM CFRP bar strengthening. Their deflection corresponding to the peak load was increased by 33% in average.

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This paper presents an experimental study evaluating the effectiveness of the Near Surface Mounted (NSM) technique with innovative manually made FRP bars (MMFRP) for shear strengthening of RC beams. RC beams designed to fail in shear were tested in three-point bending. To delay the onset of MMFRP bar debonding, a new anchorage is also developed and tested. This paper reports the results of a series of tests on simply supported rectangular RC beams, strengthened in shear with MMFRP bar either with or without the proposed anchorage. The load-deflection responses of all test beams are plotted, in addition to selected strain results. Performance and the failure modes of the test beams are presented and discussed in this paper. The proposed MMFRP bars and end anchorage enhanced the shear capacity between 25 to 48% over the control specimen. Furthermore, the adoption of the proposed end anchorage of MMFRP bars significantly enhanced the ductility of the test specimens.

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The non-covalent incorporation of responsive luminescent lanthanide, Ln(iii), complexes with orthogonal outputs from Eu(iii) and Tb(iii) in a gel matrix allows for in situ logic operation with colorimetric outputs. Herein, we report an exemplar system with two inputs ([H(+)] and [F(-)]) within a p(HEMA-co-MMA) polymer organogel acting as a dual-responsive device and identify future potential for such systems.

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Aberrant activation of Wnt/β-catenin signaling, resulting in the expression of Wnt-regulated oncogenes, is recognized as a critical factor in the etiology of colorectal cancer. Occupancy of β-catenin at promoters of Wnt target genes drives transcription, but the mechanism of β-catenin action remains poorly understood. Here, we show that CARM1 (coactivator-associated arginine methyltransferase 1) interacts with β-catenin and positively modulates β-catenin-mediated gene expression. In colorectal cancer cells with constitutively high Wnt/β-catenin activity, depletion of CARM1 inhibits expression of endogenous Wnt/β-catenin target genes and suppresses clonal survival and anchorage-independent growth. We also identified a colorectal cancer cell line (RKO) with a low basal level of β-catenin, which is dramatically elevated by treatment with Wnt3a. Wnt3a also increased the expression of a subset of endogenous Wnt target genes, and CARM1 was required for the Wnt-induced expression of these target genes and the accompanying dimethylation of arginine 17 of histone H3. Depletion of β-catenin from RKO cells diminished the Wnt-induced occupancy of CARM1 on a Wnt target gene, indicating that CARM1 is recruited to Wnt target genes through its interaction with β-catenin and contributes to transcriptional activation by mediating events (including histone H3 methylation) that are downstream from the actions of β-catenin. Therefore, CARM1 is an important positive modulator of Wnt/β-catenin transcription and neoplastic transformation, and may thereby represent a novel target for therapeutic intervention in cancers involving aberrantly activated Wnt/β-catenin signaling.