1,093 research outputs found

    Contemporary views on inflammatory pain mechanisms: TRPing over innate and microglial pathways.

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    Tissue injury, whether by trauma, surgical intervention, metabolic dysfunction, ischemia, or infection, evokes a complex cellular response (inflammation) that is associated with painful hyperalgesic states. Although in the acute stages it is necessary for protective reflexes and wound healing, inflammation may persist well beyond the need for tissue repair or survival. Prolonged inflammation may well represent the greatest challenge mammalian organisms face, as it can lead to chronic painful conditions, organ dysfunction, morbidity, and death. The complexity of the inflammatory response reflects not only the inciting event (infection, trauma, surgery, cancer, or autoimmune) but also the involvement of heterogeneous cell types including neuronal (primary afferents, sensory ganglion, and spinal cord), non-neuronal (endothelial, keratinocytes, epithelial, and fibroblasts), and immune cells. In this commentary, we will examine 1.) the expression and regulation of two members of the transient receptor potential family in primary afferent nociceptors and their activation/regulation by products of inflammation, 2.) the role of innate immune pathways that drive inflammation, and 3.) the central nervous system's response to injury with a focus on the activation of spinal microglia driving painful hyperalgesic states

    Obstacle-Aware Wireless Video Sensor Network Deployment For 3D Indoor Space Monitoring

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    In recent years wireless video sensors networks (WVSNs) have emerged as a leading technology for monitoring 3D indoor space in campus, industrial and medical areas as well as other types of environments. In contrast to traditional sensors such as heat or light sensors often considered with omnidirectional sensing range, the sensing range of a video sensor is directional and can be deemed as a pyramid-shape in 3D. Moreover, in an indoor environment, there are often obstacles such as lamp stands or furniture, which introduce additional challenges and further render the deployment solutions for traditional sensors and 2D sensing field inapplicable or incapable of solving the WVSN deployment problem for 3D indoor space monitoring. In this thesis, we take the first attempt to address this by modeling the general problem in a continuous space and strive to minimize the number of required video sensors to cover the given 3D regions. We then convert it into a discrete version by incorporating 3D grids for our discrete model, which can achieve arbitrary approximation precision by adjusting the grid granularity. We also create two strategies for dealing with stationary obstacles existed in the 3D indoor space, namely, Divide and Conquer Detection strategy and Accurate Detection strategy. We propose a greedy heuristic and an enhanced Depth First Search (DFS) algorithm to solve the discrete version problem where the latter, if given enough time can return the optimal solution. We evaluate our solutions with a customized simulator that can emulate the actual WVSN deployment and 3D indoor space coverage. The evaluation results demonstrate that our greedy heuristic can reduce the required video sensors by up to 47% over a baseline algorithm, and our enhanced DFS can achieve an additional reduction of video sensors by up to 25%

    Analysis of Liquid-Phase Chemical Detection Using Guided Shear Horizontal-Surface Acoustic Wave Sensors

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    Direct chemical sensing in liquid environments using polymer-guided shear horizontal surface acoustic wave sensor platforms on 36° rotated Y-cut LiTaO3 is investigated. Design considerations for optimizing these devices for liquid-phase detection are systematically explored. Two different sensor geometries are experimentally and theoretically analyzed. Dual delay line devices are used with a reference line coated with poly (methyl methacrylate) (PMMA) and a sensing line coated with a chemically sensitive polymer, which acts as both a guiding layer and a sensing layer or with a PMMA waveguide and a chemically sensitive polymer. Results show the three-layer model provides higher sensitivity than the four-layer model. Contributions from mass loading and coating viscoelasticity changes to the sensor response are evaluated, taking into account the added mass, swelling, and plasticization. Chemically sensitive polymers are investigated in the detection of low concentrations (1-60 ppm) of toluene, ethylbenzene, and xylenes in water. A low-ppb level detection limit is estimated from the present experimental measurements. Sensor properties are investigated by varying the sensor geometries, coating thickness combinations, coating properties, and curing temperature for operation in liquid environments. Partition coefficients for polymer-aqueous analyte pairs are used to explain the observed trend in sensitivity for the polymers PMMA, poly(isobutylene), poly(epichlorohydrin), and poly(ethyl acrylate) used in this work

    Structure of an antigen-binding fragment bound to stem-loop DNA and crystallization of recombinant haemophilus influenzae e(P4) acid phosphatase

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    The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on April 17, 2009)Includes bibliographical references.Thesis (M.S.) University of Missouri-Columbia 2006.Dissertations, Academic -- University of Missouri--Columbia -- Biochemistry (Agriculture).DNA-1 and 11F8 are anti-ss DNA antibodies derived from autoimmune lupus-prone mice. They are very similar to each other in terms of CDR sequence and preference for binding T-rich ss DNA. G1-17 is an oligonucleotide identified by in vitro selection experiments and binds with high affinity and specificity to Fab 11F8. G5-14 is a synthetic oligonucleotide with the tennucleotide sequence identical to the stem-loop portion above the bulge of G1-17. The 1.95 A ̊resolution DNA-1/G5-14 structure shows that the two DNA strands dimerize to form a double stranded DNA dumbbell and have a large conformational change including the breaking and reformation of hydrogen bonds. The most striking feature of the Fab/DNA interactions is the use of extensive [pi-pi] stacking of the DNA bases and the protein side chains. These results provide insights into the specific recognition model of anti-DNA Abs and the potential challenges in structure based drug design to treat autoimmune diseases. The second part of this thesis describes purification and crystallization of Haemophilus influenzae class C acid phosphatise P4, and acquisition of a 1.7 Å ̊resolution native X-ray diffraction data set. The space group of the crystals is P4₂2₁2 with a = 65.6, c = 101.4 A ̊one protein molecule per asymmetric unit and 37 % solvent content. This is the first report of crystallization of a class C acid phosphatase

    Inflammatory Bowel Disease: Autoimmune or Immune-mediated Pathogenesis?

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    The pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of inflammatory bowel disease (IBD), is still unclear, but both autoimmune and immune-mediated phenomena are involved. Autoimmune phenomena include the presence of serum and mucosal autoantibodies against intestinal epithelial cells in either form of IBD, and against human tropomyosin fraction five selectively in UC. In addition, perinuclear antineutrophil cytoplasmic antibodies (pANCA) are common in UC, whereas antibodies against Saccharomyces cerevisiae (ASCA) are frequently found in CD. Immune-mediate phenomena include a variety of abnormalities of humoral and cell-mediated immunity, and a generalized enhanced reactivity against intestinal bacterial antigens in both CD and UC. It is currently believed that loss of tolerance against the indigenous enteric flora is the central event in IBD pathogenesis. Various complementary factors probably contribute to the loss of tolerance to commensal bacteria in IBD. They include defects in regulatory T-cell function, excessive stimulation of mucosal dendritic cells, infections or variants of proteins critically involved in bacterial antigen recognition, such as the products of CD-associated NOD2/CARD15 mutations

    ATR-FTIR Spectroscopic Analysis of Sorption of Aqueous Analytes into Polymer Coatings Used with Guided SH-SAW Sensors

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    Attenuated total internal reflectance Fourier transform infrared (ATR-FTIR) spectroscopy was used for the investigation of sorption of aqueous solutions of analytes into polymer coatings. A series of simple model polymers, such as poly(dimethylsiloxane), poly(epichlorhydrin), and poly(isobutylene), and films and analytes, such as aqueous solutions of ethylbenzene, xylenes, toluene, and nitrobenzene, were used to evaluate the use of ATR-FTIR spectroscopy as a screening tool for sensor development. The ratios of integrated infrared absorption bands provided a simple and efficient method for predicting trends in partition coefficients. Responses of polymer-coated guided shear horizontal surface acoustic wave (SH-SAW) sensor platforms to the series of analytes, using polymer coatings with similar viscoelastic properties, were consistent with ATR-FTIR predictions. Guided SH-SAW sensor responses were linear in all cases with respect to analyte concentration in the tested range. Comparison of ATR-FTIR data with guided SH-SAW sensor data identifies cases where mass loading is not the dominant contribution to the response of the acoustic wave sensor. ATR-FTIR spectra of nitrobenzene, coupled with computational chemistry, provided additional insight into analyte/polymer interactions
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