450 research outputs found
GRB 120729A: External Shock Origin for Both the Prompt Gamma-Ray Emission and Afterglow
Gamma-ray burst (GRB) 120729A was detected by Swift/BAT and Fermi/GBM, and then rapidly observed by Swift/XRT, Swift/UVOT, and ground-based telescopes. It had a single long and smooth \gamma-ray emission pulse, which extends continuously to the X-rays. We report Lick/KAIT observations of the source, and make temporal and spectral joint fits of the multiwavelength light curves of GRB 120729A. It exhibits achromatic light-curve behavior, consistent with the predictions of the external shock model. The light curves are decomposed into four typical phases: onset bump (Phase I), normal decay (Phase II), shallow decay (Phase III), and post-jet break (Phase IV). The spectral energy distribution (SED) evolves from prompt \gamma-ray emission to the afterglow with photon index from Γγ=1.36 to Γ≈1.75. There is no obvious evolution of the SED during the afterglow. ...(Please see article full tet for complete abstract.
One-pot synthesis of Pd-Pt@Pd core-shell nanocrystals with enhanced electrocatalytic activity for formic acid oxidation
NSFC [21361005, 21073152, 21373175]; Fujian Provincial Department of Science and Technology [2008F3099]; Foundation for the Talents by the Guizhou University [X060025]; Natural Science Foundation of Guizhou Province [20072013]Well-defined Pd-Pt@Pd core-shell nanocrystals with a Pd-Pt alloy core and a conformal Pd shell of similar to 2-3 nm were directly synthesized through a one-pot, aqueous solution approach without any preformed Pd or Pt seeds. These Pd-Pt@Pd core-shell nanocrystals show an enhanced electrocatalytic activity for formic acid oxidation compared with commercial Pd black
Time-dependent Ginzburg-Landau Equation in the Nambu--Jona-Lasinio Model
We apply the closed time-path Green function formalism in the
Nambu--Jona-Lasinio model. First of all, we use this formalism to obtain the
well-known gap equation for the quark condensate in a stationary homogeneous
system. We have also used this formalism to obtain the Ginzburg-Landau (GL)
equation and the time-dependent Ginzburg-Landau (TDGL) equation for the chiral
order parameter in an inhomogeneous system. In our derived GL and TDGL
equations, there is no other parameters except for those in the original NJL
model.Comment: 20 pages, no figures. Version to appear in Nuclear Physics
Superconducting Diode Effect and Large Magnetochiral Anisotropy in T-MoTe Thin Film
In the absence of time-reversal invariance, metals without inversion symmetry
may exhibit nonreciprocal charge transport -- a magnetochiral anisotropy that
manifests as unequal electrical resistance for opposite current flow
directions. If superconductivity also sets in, the charge transmission may
become dissipationless in one direction while remaining dissipative in the
opposite, thereby realizing a superconducting diode. Through both
direct-current and alternating-current measurements, we study the nonreciprocal
effects in thin films of the noncentrosymmetric superconductor
T-MoTe\textsubscript{2} with disorders. We observe nonreciprocal
superconducting critical currents with a diode efficiency close to 20\%~, and a
large magnetochiral anisotropy coefficient up to
\SI{5.9e8}{\per\tesla\per\ampere}, under weak out-of-plane magnetic field in
the millitesla range. The great enhancement of rectification efficiency under
out-of-plane magnetic field is likely abscribed to the vortex ratchet effect,
which naturally appears in the noncentrosymmetric superconductor with
disorders. Intriguingly, unlike the finding in Rashba systems, the strongest
in-plane nonreciprocal effect does not occur when the field is perpendicular to
the current flow direction. We develop a phenomenological theory to demonstrate
that this peculiar behavior can be attributed to the asymmetric structure of
spin-orbit coupling in T-MoTe\textsubscript{2}. Our study highlights how
the crystallographic symmetry critically impacts the nonreciprocal transport,
and would further advance the research for designing the superconducting diode
with the best performance.Comment: 7 pages, 5figure
Liraglutide Ameliorates β-Amyloid Deposits and Secondary Damage in the Ipsilateral Thalamus and Sensory Deficits After Focal Cerebral Infarction in Rats
Focal cerebral infarction causes β-amyloid (Aβ) deposition and secondary neuronal degeneration in the ipsilateral thalamus. Thalamus is the subcortical center of sensory, the damage of thalamus could cause sensory deficits. The present study aimed to investigate the protective effects of liraglutide, a long-acting glucagon-like peptide-1 (GLP)-1 receptor agonist, on Aβ deposits and secondary damage in the ipsilateral thalamus after focal cerebral infarction. In addition, this study was conducted to investigate whether liraglutide could improve sensory function after focal cerebral infarction. Forty-two male Sprague–Dawley rats were subjected to distal middle cerebral artery occlusion (MCAO) and then randomly divided into liraglutide and vehicle groups, and 14 sham-operated rats as control. At 1 h after MCAO, rats in the liraglutide and vehicle groups were subcutaneously injected with liraglutide (100 μg/kg/d) and isopyknic vehicle, respectively, once a day for 7 days. Sensory function and secondary thalamic damage were assessed using adhesive-removal test and Nissl staining and immunostaining, respectively, at 7 days after MCAO. Terminal deoxynucleotidyl transferase 2’-deoxyuridine 5’-triphosphate nick end labeling and Western blot were used to detect neuronal apoptosis. The results showed that liraglutide improved sensory deficit compared to the controls. Liraglutide treatment significantly reduced Aβ deposition compared with the vehicle treatment. Liraglutide treatment decreased the neuronal loss, astroglial and microglial activation, and apoptosis compared with the vehicle treatment. Liraglutide significantly down-regulated the expression of Bcl-2 and up-regulated that of Bax in the ipsilateral thalamus compared with the vehicle group. These results suggest that liraglutide ameliorates the deposition of Aβ and secondary damage in the ipsilateral thalamus, potentially contributing to improve sensory deficit after focal cerebral infarction
Application of Flexible Bronchoscopy in Inhalation Lung Injury
Background: As acute inhalational injury is an uncommon presentation to most institutions, a standard approach to its assessment and management, especially using flexible bronchoscopy, has not received significant attention. Methods: The objective of this study is to evaluate the value of using flexible bronchoscopy as part of the evaluation and management of patients with inhalational lung injury. Twenty-three cases of inhalational lung injury were treated in our three hospitals after a fire in a residential building. The twenty cases that underwent bronchoscopy as part of their management are included in this analysis. After admission, the first bronchoscopy was conducted within 18-72 hours post inhalational injury. G2-level patients were reexamined 24 hours after the first bronchoscopy, while G1-level patients were reexamined 72 hours later. Subsequently, all patients were re-examined every 2-3 days until recovered or until only tunica mucosa bronchi congestion was identified by bronchoscopy. Results: Twenty patients had airway injury diagnosed by bronchoscopy including burns to the larynx and glottis or large airways. Bronchoscopic classification of the inhalation injury was performed, identifying 12 cases of grade G1 changes and 8 cases of grade G2. The airway injury in the 12 cases of grade G1 patients demonstrated recovery in 2-8 days, in the airway injury of the 8 cases of grade G2 patients had a prolonged recovery with airway injury improving in 6-21 days averaged. The difference in recovery time between the two groups was significant (P Conclusions: The use of flexible bronchoscopy has great value in the diagnosis of inhalational injury without any complications. Its use should be incorporated into clinical practice
Monoclonal antibody induced with inactived EV71-Hn2 virus protects mice against lethal EV71-Hn2 virus infection
<p>Abstract</p> <p>Background</p> <p>Enterovirus 71 (EV71) is a viral pathogen that belongs to the <it>Picornaviridae </it>family, EV71-infected children can develop severe neurological complications leading to rapid clinical deterioration and death.</p> <p>Results</p> <p>In this study, several monoclonal antibodies (MAbs) were produced by immunizing mice with the inactived EV71 Henan (Hn2) virus strain. The isolated MAbs were characterised by <it>in vitro </it>neutralizing analysis and peptide ELISA. ELISA assay showed that the neutralizing monoclonal antibody 4E8 specifically reacted with synthetic peptides which contain amino acid 240-250 and 250-260 of EV71 VP1. The <it>in vivo </it>protection assay showed that 4E8 can protect two-day-old BALB/c mice against the lethal challenge of EV71 virus.</p> <p>Conclusion</p> <p>The MAb 4E8 could be a promising candidate to be humanized and used for treatment of EV71 infection.</p
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