498 research outputs found

    Congenital tracheoesophageal fistulas presenting in adults: Presentation of two cases and a synopsis of the literature

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    A Recombinant PvpA Protein-Based Diagnostic Prototype for Rapid Screening of Chicken Mycoplasma gallisepticum infections

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    Cataloged from PDF version of article.Mycoplasma gallisepticum is the primary agent of chronic respiratory disease causing important economic losses in the poultry industry. Serological monitoring is essential to maintain mycoplasma-free breeder flocks and often complicated by the cross-reactions between different mycoplasma species. To overcome serological cross-reactions, a large fragment of the M. gallisepticum PvpA cytadhesin, species-specific surface-exposed protein, was produced in E. coli as a recombinant protein (rPvpA336) and used as a potential diagnostic antigen. The rPvpA336 protein possesses 336 mycoplasma-specific amino acids with relative molecular weight of 44 kDa. A deletion region of 37 amino acids was identified when compared to the wild-type PvpA protein. Immunoreactivity of the rPvpA336 protein has been demonstrated by Western blot analysis with M. gallisepticum-positive and -negative chicken sera. Furthermore, an enzymatic rapid immunofiltration assay (ERIFA) prototype based on the rPvpA336 protein has been developed and its species-specific detection capability has been demonstrated by using M. gallisepticum and/or M. synoviae-positive and -negative chicken sera. In addition to its species-specificity, the ERIFA prototype presents certain advantages such as rapidity, field-applicability and cost-effectiveness. Therefore, these advantages would make the prototype a species-specific rapid diagnostic tool of choice in the field and limited laboratory conditions for screening M. gallisepticum infections. © 2007 Elsevier B.V. All rights reserved

    A supramolecular peptide nanofiber templated Pd nanocatalyst for efficient Suzuki coupling reactions under aqueous conditions

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    Cataloged from PDF version of article.A bioinspired peptide amphiphile nanofiber template for formation of one-dimensional Pd nanostructures is demonstrated. The Pd and peptide nanocatalyst system enabled efficient catalytic activity in Suzuki coupling reactions in water at room temperature. The nanocatalyst system can be easily separated and reused in successive reactions without significant loss in activity and structural integrity. This journal is © 2012 The Royal Society of Chemistry

    HandVR: a hand-gesture-based interface to a video retrieval system

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    Cataloged from PDF version of article.Using one's hands in human-computer interaction increases both the effectiveness of computer usage and the speed of interaction. One way of accomplishing this goal is to utilize computer vision techniques to develop hand-gesture-based interfaces. A video database system is one application where a hand-gesture-based interface is useful, because it provides a way to specify certain queries more easily. We present a hand-gesture-based interface for a video database system to specify motion and spatiotemporal object queries. We use a regular, low-cost camera to monitor the movements and configurations of the user's hands and translate them to video queries. We conducted a user study to compare our gesture-based interface with a mouse-based interface on various types of video queries. The users evaluated the two interfaces in terms of different usability parameters, including the ease of learning, ease of use, ease of remembering (memory), naturalness, comfortable use, satisfaction, and enjoyment. The user study showed that querying video databases is a promising application area for hand-gesture-based interfaces, especially for queries involving motion and spatiotemporal relations. © 2014 Springer-Verlag London

    Applying Deep Learning in Augmented Reality Tracking

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    An existing deep learning architecture has been adapted to solve the detection problem in camera-based tracking for augmented reality (AR). A known target, in this case a planar object, is rendered under various viewing conditions including varying orientation, scale, illumination and sensor noise. The resulting corpus is used to train a convolutional neural network to match given patches in an incoming image. The results show comparable or better performance compared to state of art methods. Timing performance of the detector needs improvement but when considered in conjunction with the robust pose estimation process promising results are shown. © 2016 IEEE

    Self-Assembled Peptide Nanofiber Templated One-Dimensional Gold Nanostructures Exhibiting Resistive Switching

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    Cataloged from PDF version of article.An amyloid-like peptide molecule self-assembling into one-dimensional nanofiber structure in ethanol was designed and synthesized with functional groups that can bind to gold ions. The peptide nanofibers were used as templates for nucleation and growth of one-dimensional gold nanostructures in the presence of ascorbic acid as reducing agent. We performed multistep seed-mediated synthesis of gold nanoparticles by changing peptide/gold precursor and peptide/reducing agent ratios. Gold nanostructures with a wide range of morphologies such as smooth nanowires, noodle-like one-dimensional nanostructures, and uniform aggregates of spherical nanoparticles were synthesized by use of an environmentally friendly synthesis method. Nanoscale electrical properties of gold-peptide nanofibers were investigated using atomic force microscopy. Bias dependent current (IV) measurements on thin films of gold-peptide nanofiber hybrid revealed tunneling dominated transport and resistive switching. Gold-peptide nanofiber composite nanostructures can provide insight into electrical conduction in biomolecular/inorganic composites, highlighting their potential applications in electronics and optics. © 2012 American Chemical Society

    Inadequate Loading Stimulus on ISS Results in Bone and Muscle Loss

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    INTRODUCTION Exercise has been the primary countermeasure to combat musculoskeletal changes during International Space Station (ISS) missions. However, these countermeasures have not been successful in preventing loss of bone mineral density (BMD) or muscle volume in crew members. METHODS We examined lower extremity loading during typical days on-orbit and on Earth for four ISS crew members. In-shoe forces were monitored using force-measuring insoles placed inside the shoes. BMD (by DXA), muscle volumes (by MRI), and strength were measured before and after long-duration spaceflight (181 +/- 15 days). RESULTS The peak forces measured during ISS activity were significantly less than those measured in 1g for the same activities. Typical single-leg loads on-orbit during walking and running were 0.89 +/- 0.17 body weights (BW) and 1.28 +/- 0.18 BW compared to 1.18 +/- 0.11 BW and 2.36 +/- .22 BW in 1g, respectively [2]. Crew members were only loaded for an average of 43.17 +/- 14.96 min a day while performing exercise on-orbit even though 146.8 min were assigned for exercise each day. Areal BMD decreased in the femoral neck and total hip by 0.71 +/- 0.34% and 0.81 +/- 0.21% per month, respectively. Changes in muscle volume were observed in the lower extremity (-10 to -16% calf; -4 to -7% thigh) but there were no changes in the upper extremity (+0.4 to -0.8%). Decrements in isometric and isokinetic strength at the knee (range: -10.4 to -24.1%), ankle (range: -4 to -22.3%), and elbow (range: -7.5 to - 16.7%) were also observed. Knee extension endurance tests showed an overall decline in total work (-14%) but an increased resistance to fatigue post-flight. DISCUSSION AND CONCLUSIONS Our findings support the conclusion that the measured exercise durations and/or loading stimuli were insufficient to protect bone and muscle health

    Foot Reaction Forces during Long Duration Space Flight

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    Musculoskeletal changes, particularly in the lower extremities, are an established consequence of long-duration space flight despite exercise countermeasures. It is widely believed that disuse and reduction in load bearing are key to these physiological changes, but no quantitative data characterizing the on-orbit movement environments currently exist. Here we present data from the Foot Experiment (E318) regarding astronaut activity on the ground and on-orbit during typical days from 4 International Space Station (ISS) crew members who flew during increments 6, 8, 11, and 12
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