353 research outputs found

    Composite prepreg application device

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    A heated shoe and cooled pressure roller assembly for composite prepreg application is provided. The shoe assembly includes a heated forward contact surface having a curved pressure surface. The following cooled roller provides a continuous pressure to the thermoplastic while reducing the temperature to approximately 5.degree. C. below glass transition temperature. Electric heating coils inside the forward portion of the shoe heat a thermoplastic workpiece to approximately 100.degree. C. above the glass transition. Immediately following the heated contact surface, a cooled roller cools the work. The end sharpened shape of the heated shoe trailing edge tends to prevent slag buildup and maintain a uniform, relaxed stress fabrication

    Technology and the Demand for Skill:An Analysis of Within and Between Firm Differences

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    We estimate the effects of technology investments on the demand for skilled workers using longitudinally integrated employer-employee data from the U.S. Census Bureau's Longitudinal Employer-Household Dynamics Program infrastructure files spanning two Economic Censuses (1992 and 1997). We estimate the distribution of human capital and its observable and unobservable components within each business for each year from 1992 to 1997. We measure technology using variables from the Annual Survey of Manufactures and the Business Expenditures Survey (services, wholesale and retail trade), both administered during the 1992 Economic Census. Static and partial adjustment models are fit. There is a strong positive empirical relationship between advanced technology and skill in a cross-sectional analysis of businesses in both sectors. The more comprehensive measures of skill reveal that advanced technology interacts with each component of skill quite differently: firms that use advanced technology are more likely to use high-ability workers, but less likely to use high-experience workers. These results hold even when we control for unobservable heterogeneity by means of a selection correction and by using a partial adjustment specification.

    Non-rectangular towpreg architectures

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    A shaped towpreg ribbon having a cross-sectional geometry which promotes intimate lateral contact between adjacent composite tows was prepared. The cross-sectional geometry is non-rectangular and promotes intimate lateral contact between adjacent towpreg ribbons during normal processing

    Non-rectangular towpreg architectures

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    A shaped towpreg ribbon having a cross-sectional geometry which promotes intimate lateral contact between adjacent composite tows was prepared. The cross-sectional geometry is non-rectangular and promotes intimate lateral contact between adjacent towpreg ribbons during normal processing

    Perfluorooctanoic acid exposure triggers oxidative stress in the mouse pancreas

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    • PFOA triggers focal ductal hyperplasia following 7 day exposure. • PFOA exposure increases 8-iso-PGF2α levels in the pancreas. • Antioxidant gene expression is upregulated in the pancreas following PFOA exposure. , Perfluorooctanoic acid (PFOA) is used in the manufacture of many industrial and commercial products. PFOA does not readily decompose in the environment, and is biologically persistent. Human epidemiologic and animal studies suggest that PFOA exposure elicits adverse effects on the pancreas. While multiple animal studies have examined PFOA-mediated toxicity in the liver, little is known about the potential adverse effects of PFOA on the pancreas. To address this, we treated C57Bl/6 mice with vehicle, or PFOA at doses of 0.5, 2.5 or 5.0 mg/kg BW/day for 7 days. Significant accumulation of PFOA was found in the serum, liver and pancreas of PFOA-treated animals. Histopathologic examination of the pancreas revealed focal ductal hyperplasia in mice treated with 2.5 and 5.0 mg/kg BW/day PFOA, while inflammation was observed only in the high dose group. Elevated serum levels of amylase and lipase were observed in the 2.5 mg/kg BW/day PFOA treatment group. In addition, PFOA exposure resulted in a dose-dependent increase in the level of the lipid peroxidation product 8-iso-PGF2α and induction of the antioxidant response genes Sod1, Sod2, Gpx2 and Nqo1. Our findings provide additional evidence that the pancreas is a target organ for PFOA-mediated toxicity and suggest that oxidative stress may be a mechanism through which PFOA induces histopathological changes in the pancreas

    Identification of LIMK2 as a therapeutic target in castration resistant prostate cancer

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    This study identified LIMK2 kinase as a disease-specific target in castration resistant prostate cancer (CRPC) pathogenesis, which is upregulated in response to androgen deprivation therapy, the current standard of treatment for prostate cancer. Surgical castration increases LIMK2 expression in mouse prostates due to increased hypoxia. Similarly, human clinical specimens showed highest LIMK2 levels in CRPC tissues compared to other stages, while minimal LIMK2 was observed in normal prostates. Most notably, inducible knockdown of LIMK2 fully reverses CRPC tumorigenesis in castrated mice, underscoring its potential as a clinical target for CRPC. We also identified TWIST1 as a direct substrate of LIMK2, which uncovered the molecular mechanism of LIMK2-induced malignancy. TWIST1 is strongly associated with CRPC initiation, progression and poor prognosis. LIMK2 increases TWIST1 mRNA levels upon hypoxia; and stabilizes TWIST1 by direct phosphorylation. TWIST1 also stabilizes LIMK2 by inhibiting its ubiquitylation. Phosphorylation-dead TWIST1 acts as dominant negative and fully prevents EMT and tumor formation in vivo, thereby highlighting the significance of LIMK2-TWIST1 signaling axis in CRPC. As LIMK2 null mice are viable, targeting LIMK2 should have minimal collateral toxicity, thereby improving the overall survival of CRPC patients

    Differential sexual dimorphism in bone diameters of subjects of European and African ancestry

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    The 1,589 low-income adult subjects of primarily African ancestry (American Negroes or “Blacks”) showed systematically less sexual dimorphism in total subperiosteal area (TA), medullary area (MA) and cortical area (CA) than did 4,379 low-income adult subjects of European derivation (“Whites”). These systematic findings have implications both to the sexing of skeletal remains from diverse populations and to an understanding of population divergences in bone remodeling.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37526/1/1330370116_ftp.pd

    Whole Slide Image Analysis Quantification using Aperio Digital Imaging in a Mouse Lung Metastasis Model

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    poster abstractDigital whole slide imaging is the technique of digitizing a microscope slide at the highest resolution to produce a “digital virtual microscope slide”. This digital image can be viewed in three or four fields, from low to high power, which can be commonly used to evaluate the tissue. Many of these systems have whole slide software image analysis capability. The goal of this study was to determine if the Aperio positive pixel algorithm (image analysis) could effectively quantitate metastatic mouse lung tumors in a lung section using a H&E stain. Lung sections from a mouse lung metastasis model of 8 mice per group were evaluated: control, 50mg/kg, and 75mg/kg carboplatin. H&E and Ki67 immunostain slides were scanned using the Aperio whole slide scanning system (Scanscope CS). A single field of view from each slide representing a whole lung lobe with multiple lung metastases was selected for image analysis. The standard positive pixel algorithm was altered to read the H&E slides. Various histology slides were used to validate the altered algorithm. The immunostain (Ki67) was generated using the standard positive pixel algorithm analysis. The Aperio automated positive pixel count for a Ki67 immunostain was consistent with the H&E image analysis. The values decreased with a dose dependent treatment (control vs. 50mg/kg and 75mg/kg carboplatin) and were (H&E) 37%, 28%, and 22%, and (Ki67) 9%, 5%, and 3%. The analysis had decreasing values for both the H&E and Ki67 analysis on a dose dependent drug treatment. The metastases decreased in both treatment groups compared to controls with both the H&E and Ki67 analyses. The Aperio Image Analysis positive pixel algorithm allows large areas of the lung tissue section to be examined and not just a single 25x or 40x field like many common image analyses systems

    Energy thresholds for discrete breathers in one-, two- and three-dimensional lattices

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    Discrete breathers are time-periodic, spatially localized solutions of equations of motion for classical degrees of freedom interacting on a lattice. They come in one-parameter families. We report on studies of energy properties of breather families in one-, two- and three-dimensional lattices. We show that breather energies have a positive lower bound if the lattice dimension of a given nonlinear lattice is greater than or equal to a certain critical value. These findings could be important for the experimental detection of discrete breathers.Comment: 10 pages, LaTeX, 4 figures (ps), Physical Review Letters, in prin
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