Long-duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars. Previous early optical observations of even the most exceptional GRBs (990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment. Here we report observations of the extraordinarily bright prompt optical and gamma-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks. We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet.
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http://dx.doi.org/10.1038/nature07270 | DOI Listing |
J Neuroeng Rehabil
December 2024
Laboratory for Neuro- & Psychophysiology, Department of Neurosciences, KU Leuven, Leuven, Belgium.
Background: The loss of finger control in individuals with neuromuscular disorders significantly impacts their quality of life. Electroencephalography (EEG)-based brain-computer interfaces that actuate neuroprostheses directly via decoded motor intentions can help restore lost finger mobility. However, the extent to which finger movements exhibit distinct and decodable EEG correlates remains unresolved.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
New Cornerstone Science Laboratory, Department of Physics, University of Hong Kong, Hong Kong, China.
The ability to generate Landau levels using a pseudomagnetic field (PMF), also called an artificial gauge field, opens up new pathways for exploring fundamental physics and developing novel applications based on topological protection. In this Letter, we simultaneously realize a PMF and a pseudoelectric field (PEF) on a photonic crystal platform and observe a rainbow effect of the Landau zeroth modes. While a PMF induces a series of discretized Landau levels of photons in a similar way as the quantum Hall effect for electrons, a PEF breaks the degeneracy of the flat band of Landau levels over a broad range.
View Article and Find Full Text PDFACS Photonics
December 2024
Advanced Research Center for Nanolithography, Science Park 106, 1098 XG, Amsterdam, The Netherlands.
Moderate efficiencies of nonlinear optical processes can be one of the challenges limiting even more widespread applications. Here we demonstrate a broadband and giant enhancement of nonlinear processes in ZnO through ultrafast permittivity engineering. A remarkable enhancement of the second and third harmonic generation of up to 2 orders of magnitude can be observed over a broadband range of driving wavelengths.
View Article and Find Full Text PDFOtolaryngol Head Neck Surg
December 2024
Department of Otorhinolaryngology, Gazi University Faculty of Medicine, Ankara, Turkey.
Objective: This study aimed to attenuate cochlear inflammation following noise-induced hearing loss by targeting IL-1. We evaluated the effectiveness of IL-1 inhibition through auditory and histological assessments in an animal model.
Study Design: Experimental animal study.
Soft Matter
December 2024
South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
Understanding the interplay among the mechanical behavior, ionic conductivity and chain dynamics of ionogels is essential for designing flexible conductors that exhibit both high conductivity and excellent mechanical properties. In this study, ionogels were synthesized the radical polymerization of ,'-dimethylacrylamide (DMAA) and methacrylic acid (MAAc) monomers in the presence of ionic liquid 1-ethyl-3-methylimidazolium trifluoromethane sulfonate ([EMIM][OTf]). By varying the mass content of ionic liquid within ionogels, we investigated the mechanical behavior and ionic conductivity at the macroscopic scale using tensile, rheological testing and electrochemical impedance spectroscopy, as well as the dynamic behavior of chain segments and ions within the network at the microscopic scale using broadband dielectric relaxation spectroscopy (BDS) over a broad temperature range.
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