Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Influence of murine hepatitis induced by D-(+)-galactosamine hydrochloride and lipopolysaccharide on gene expression of polyethylenimine/plasmid DNA polyplex

We investigated the influence of murine hepatitis induced by D-(+)-galactosamine and lipopolysaccharide (DGalN/LPS) on polyethylenimine (PEI)-mediated plasmid DNA (pDNA) delivery. pDNA encoding firefly luciferase was used as the model reporter gene. PEI was used as the non-viral vector because of its high gene expression and low toxicity. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in mice indicated the highest peaks at 12 h after D-GalN/LPS injection, then the activities of serum ALT and AST rapidly decreased. We determined luciferase activity in various organs of D-GalN/LPS-treated mice and control mice after an intravenous administration of PEI/pDNA complexes. High transgene expression was observed in the liver, spleen, and lung of both mice. Compared to the control mice, a significant increase of transgene expression was observed in the liver of D-GalN/LPS-treated mice after D-GalN/LPS injection. The transgene expression in the spleen and lung decreased at 6 and 12 h after D-GalN/LPS injection. In conclusion, we found that murine hepatitis induced by D-GalN/LPS injection can influence PEI-mediated pDNA delivery and its influence was different from that induced by CCl4 injection which was reported previously. These results demonstrated the necessity of considering the timing and dose of gene therapy according to the disease and its stage