924 research outputs found
TMRT observations of 26 pulsars at 8.6 GHz
Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio
Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities
and pulse width parameters of these pulsars are estimated. For eleven pulsars
these are the first high-frequency observations and for a further four, our
observations have a better signal-to-noise ratio than previous observations.
For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed
profiles. A comparison of 19 profiles with those at other frequencies shows
that in nine cases the separation between the outmost leading and trailing
components decreases with frequency, roughly in agreement with
radius-to-frequency mapping, whereas in the other ten the separation is nearly
constant. Different spectral indices of profile components lead to the
variation of integrated pulse profile shapes with frequency. In seven pulsars
with multi-component profiles, the spectral indices of the central components
are steeper than those of the outer components. For the 12 pulsars with
multi-component profiles in the high-frequency sample, we estimate the core
width using gaussian fitting and discuss the width-period relationship.Comment: 33 pages, 49 figures, 5 Tables; accepted by Ap
Nitroglycerine-induced nitrate tolerance compromises propofol protection of the endothelial cells against TNF-α: the role of PKC-β2 and NADPH oxidase
published_or_final_versio
Observation of non-Hermitian antichiral edge currents
Non-Hermitian topological photonics is of great interest in bridging
topological matter with gain/dissipation engineering in optics. A key problem
in this direction is the interplay between the effective gauge potential and
the non-Hermiticity. Here we tackle this problem in a synthetic non-Hermitian
Hall ladder and experimentally observe antichiral edge currents (ACECs) of
photons, by tuning the locally uniform effective magnetic flux and the on-site
gain/loss. Such ACECs provide a topological method to probe the signatures of
the non-Hermitian skin effect (NHSE) from steady-state bulk dynamics. The
universality of this method is verified by its generalization to three
dimensions. This study paves a way to investigate exotic non-Hermitian
topological physics and has potential applications in topological photonics
engineering
Orthotopic and heterotopic tracheal transplantation model in studying obliterative bronchiolitis
AbstractBackgroundSeveral animal models have been established to investigate the mechanisms of obliterative bronchiolitis after lung transplantation. In this study, we compared three prevalent murine models of obliterative bronchiolitis in terms of several basic pathologic changes in a relatively short span of time after transplantation.MethodsEach of the recipient mice simultaneously received orthotopic, intra-omental and subcutaneous tracheal transplantation in both syngeneic and allogeneic settings. No immunosuppressive treatment was administered. Tracheal grafts were harvested on Day 14, 21 and 28 after transplantation for histological and immunohistochemical analyses.ResultsSyngeneic tracheal grafts from different transplant sites retained normal histologic structures, while their corresponding allografts demonstrated more occlusion of the airway lumen as well as more infiltration of CD4+/CD8+ mononuclear cells and myofibroblasts, but less regenerative epithelium and neovascularized vessels at indicated times (P<0.05). Compared with two heterotopic allografts, orthotopic allografts had less occlusion of the tracheal lumen as well as less infiltration of CD4+/CD8+ mononuclear cells and myofibroblasts, but more regenerative epithelium and neovascularized vessels (P<0.05).ConclusionsOrthotopic tracheal transplantation in mice can be considered as a model to study early stages of obliterative bronchiolitis, and heterotopic tracheal transplantation can be a model for late stages of obliterative bronchiolitis
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