27 research outputs found

    Large-area scanning probe nanolithography facilitated by automated alignment of probe arrays

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    A method for the automated alignment of scanning probe polymer pen arrays is reported. This system enables nanolithography over large (cm2) areas with high uniformity, with any misalignment being ≤0.0003°.</p

    Higher D or Li: Probes of Physics beyond the Standard Model

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    Standard Big Bang Nucleosynthesis at the baryon density determined by the microwave anisotropy spectrum predicts an excess of \li7 compared to observations by a factor of 4-5. In contrast, BBN predictions for D/H are somewhat below (but within ~2 \sigma) of the weighted mean of observationally determined values from quasar absorption systems. Solutions to the \li7 problem which alter the nuclear processes during or subsequent to BBN, often lead to a significant increase in the deuterium abundance consistent with the highest values of D/H seen in absorption systems. Furthermore, the observed D/H abundances show considerable dispersion. Here, we argue that those systems with D/H \simeq 4 \times 10^{-5} may be more representative of the primordial abundance and as a consequence, those systems with lower D/H would necessarily have been subject to local processes of deuterium destruction. This can be accounted for by models of cosmic chemical evolution able to destroy in situ Deuterium due to the fragility of this isotope.Comment: 22 pages, 8 figure

    A High-Throughput Assay for Arylamine Halogenation Based on a Peroxidase Mediated Quinone-Amine Coupling with Applications in the Screening of Enzymatic Halogenations.

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    Arylhalides are important building blocks in many fine chemicals, pharmaceuticals and agrochemicals, and there has been increasing interest in the development of more “green” halogenation methods based on enzyme catalysis. However, the screening and development of new enzymes for biohalogenation has been hampered by a lack of high-throughput screening methods. Described herein is the development of a colorimetric assay for detecting both chemical and enzymatic arylamine halogenation reactions in an aqueous environment. The assay is based on the unique UV/Vis spectrum created by the formation of an ortho-benzoquinone-amine adduct, which is produced by the peroxidase-catalysed benzoquinone generation, followed by Michael addition of either a halogenated or non-halogenated arylamine. This assay is sensitive, rapid and amenable to high-throughput screening platforms. We have also shown this assay to be easily coupled to a flavin-dependent halogenase, which currently lacks any convenient colorimetric assay, in a “one-pot” workflow

    Parallelized Biocatalytic Scanning Probe Lithography for the Additive Fabrication of Conjugated Polymer Structures

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    Multiplexed scanning probes functionalized with a peroxidase enables large area constructive lithography of polyanilines.</p

    CCR3 Blockade Attenuates Eosinophilic Ileitis and Associated Remodeling

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    Intestinal remodeling and stricture formation is a complication of inflammatory bowel disease (IBD) that often requires surgical intervention. Although eosinophils are associated with mucosal remodeling in other organs and are increased in IBD tissues, their role in IBD-associated remodeling is unclear. Histological and molecular features of ileitis and remodeling were assessed using immunohistochemical, histomorphometric, flow cytometric, and molecular analysis (real-time RT-PCR) techniques in a murine model of chronic eosinophilic ileitis. Collagen protein was assessed by Sircol assay. Using a spontaneous eosinophilic Crohn’s-like mouse model SAMP1/SkuSlc, we demonstrate an association between ileitis progression and remodeling over the course of 40 weeks. Mucosal and submucosal eosinophilia increased over the time course and correlated with increased histological inflammatory indices. Ileitis and remodeling increased over the 40 weeks, as did expression of fibronectin. CCR3-specific antibody-mediated reduction of eosinophils resulted in significant decrease in goblet cell hyperplasia, muscularis propria hypertrophy, villus blunting, and expression of inflammatory and remodeling genes, including fibronectin. Cellularity of local mesenteric lymph nodes, including T- and B-lymphocytes, was also significantly reduced. Thus, eosinophils participate in intestinal remodeling, supporting eosinophils as a novel therapeutic target
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