4,708 research outputs found

    New targets for resolution of airway remodeling in obstructive lung diseases.

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    Airway remodeling (AR) is a progressive pathological feature of the obstructive lung diseases, including asthma and chronic obstructive pulmonary disease (COPD). The pathology manifests itself in the form of significant, progressive, and (to date) seemingly irreversible changes to distinct respiratory structural compartments. Consequently, AR correlates with disease severity and the gradual decline in pulmonary function associated with asthma and COPD. Although current asthma/COPD drugs manage airway contraction and inflammation, none of these effectively prevent or reverse features of AR. In this review, we provide a brief overview of the features and putative mechanisms affecting AR. We further discuss recently proposed strategies with promise for deterring or treating AR

    Dielectric characterization and molecular interaction behaviour in binary mixtures of methyl acetate with 1-butanol and 1-pentanol

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    900-910The dielectric constant (ɛs) and relaxation time () of binary mixtures of methyl acetate with alcohols (1-butanol and 1-pentanol) have been investigated at fifteen molar concentrations over the entire mixing range at 288 K, 298 K, 308 K and 318 K using time domain reflectometery technique over the frequency range from 10 MHz to 10 GHz. The relaxation in these mixtures can be described by a single relaxation time using the Debye model. The concentration dependent plots of excess dielectric constant (ɛE), excess inverse relaxation time (1/)E, Kirkwood correlation factor (geff), thermodynamic parameters such as enthalpy of activation (H) and Gibbs free energy (G) of activation and Bruggman factor (fB) have been used to explore the complexes formed between unlike molecules, dipolar ordering, hydrogen bond molecular connectivity’s and their strength in the binary mixtures. Results confirm that there are strong hydrogen-bond interactions between unlike molecules of ester-alcohol mixtures

    Proton Decay and Related Processes in Unified Models with Gauged Baryon Number:

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    In unification models based on SU(15) or SU(16), baryon number is part of the gauge symmetry, broken spontaneously. In such models, we discuss various scenarios of important baryon number violating processes like proton decay and neutron-antineutron oscillation. Our analysis depends on the effective operator method, and covers many variations of symmetry breaking, including different intermediate groups and different Higgs boson content. We discuss processes mediated by gauge bosons and Higgs bosons parallely. We show how accidental global or discrete symmetries present in the full gauge invariant Lagrangian restrict baryon number violating processes in these models. In all cases, we find that baryon number violating interactions are sufficiently suppressed to allow grand unification at energies much lower than the usual 101610^{16} GeV.Comment: (32 pages LATEX) [DOE-ER\,40757-022, CPP-93-22] {Small changes made and two references added. This version will appear in Phys. Rev. D

    Microprocessor Controller in Closed Loop Angular Position Servo System P.

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    Integrated command, control and copmunication systems are based on the use of computers for digital data processing. The weapon system platforms like missile launchers are given input command for accurate and quick positioning in azimuth and elevation. The technologies of sensors, signal conditioning and associated solid state electronics have moved from analog to digital. Therefore, a position controller has to be designed around a microprocessor in embedded form for usage in such servo control systems. This paper highlights the basic approach for such design and problems which need to be tackled during actual implementation

    Bow Shocks from Neutron Stars: Scaling Laws and HST Observations of the Guitar Nebula

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    The interaction of high-velocity neutron stars with the interstellar medium produces bow shock nebulae, where the relativistic neutron star wind is confined by ram pressure. We present multi-wavelength observations of the Guitar Nebula, including narrow-band H-alpha imaging with HST/WFPC2, which resolves the head of the bow shock. The HST observations are used to fit for the inclination of the pulsar velocity vector to the line of sight, and to determine the combination of spindown energy loss, velocity, and ambient density that sets the scale of the bow shock. We find that the velocity vector is most likely in the plane of the sky. We use the Guitar Nebula and other observed neutron star bow shocks to test scaling laws for their size and H-alpha emission, discuss their prevalence, and present criteria for their detectability in targeted searches. The set of H-alpha bow shocks shows remarkable consistency, in spite of the expected variation in ambient densities and orientations. Together, they support the assumption that a pulsar's spindown energy losses are carried away by a relativistic wind that is indistinguishable from being isotropic. Comparison of H-alpha bow shocks with X-ray and nonthermal, radio-synchrotron bow shocks produced by neutron stars indicates that the overall shape and scaling is consistent with the same physics. It also appears that nonthermal radio emission and H-alpha emission are mutually exclusive in the known objects and perhaps in all objects.Comment: 12 pages, 7 figures (3 degraded), submitted to ApJ; minor revisions and updates in response to referee report. (AASTeX, includes emulateapj5 and onecolfloat5.

    Autophagy and airway fibrosis: Is there a link?

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    © 2017 Kota A et al. In the past decade, an emerging process named "autophagy" has generated intense interest in many chronic lung diseases. Tissue remodeling and fibrosis is a common feature of many airway diseases, and current therapies do not prevent or reverse these structural changes. Autophagy has evolved as a conserved process for bulk degradation and recycling of cytoplasmic components to maintain basal cellular homeostasis and healthy organelle populations in the cell. Furthermore, autophagy serves as a cell survival mechanism and can also be induced by chemical and physical stress to the cell. Accumulating evidence demonstrates that autophagy plays an essential role in vital cellular processes, including tissue remodeling. This review will discuss some of the recent advancements made in understanding the role of this fundamental process in airway fibrosis with emphasis on airway remodeling, and how autophagy can be exploited as a target for airway remodeling in asthma and chronic obstructive pulmonary disease
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