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We report a case of lethal varicella developed in an immunocompromised man in his seventies. A study by immunohistochemistry and in situ hybridization was conducted revealing the presence of the glycoprotein gpI specific for VZV and its corresponding nucleic acids found in multiple foci of most tissues and organs, except in the brain and paravertebral sympathetic ganglia.

Inorganic-organic hybrid polymer (ORMOCER(R)) coatings with a fast photochromic response and high photochromic activity were: prepared by incorporation of the photochromophore Variacrolo Blue D into hydrolysates of organofunctional alkoxysilanes, with subsequent thermal curing. Besides the traditional way of doping the sol-gel materials by physically dissolving the dye, a graftable derivative was prepared and covalently attached to two matrices of different rigidity. The resulting thin films showed good photochromic activity, no blooming, mechanical properties at least comparable to the pure host material, and can be applied to different glass and plastic substrates. Photochemical degradation was studied by means of artificial weathering and factors influencing the fatigue behaviour of the coatings assessed. The graftable dye showed improved photochemical fatigue resistance. The more rigid matrix was preferable, too, in terms of photodegradation.

Deriving physical parameters from gamma-ray burst afterglow observations remains a challenge, even now, 20 years after the discovery of afterglows. The main reason for the lack of progress is that the peak of the synchrotron emission is in the sub-mm range, thus requiring radio observations in conjunction with X-ray/optical/near-infrared data in order to measure the corresponding spectral slopes and consequently remove the ambiguity wrt. slow vs. fast cooling and the ordering of the characteristic frequencies. We observed GRB 151027B, the 1000th Swift-detected GRB, with GROND in the optical-NIR, ALMA in the sub-millimeter, ATCA in the radio band, and combine this with public Swift-XRT X-ray data. While some observations at crucial times only return upper limits or surprising features, the fireball model is narrowly constrained by our data set, and allows us to draw a consistent picture with a fully-determined parameter set. Surprisingly, we find rapid, large-amplitude flux density variations in the radio band which are extreme not only for GRBs, but generally for any radio source. We interpret these as scintillation effects, though the extreme nature requires either the scattering screen to be at much smaller distance than usually assumed, multiple screens, or a combination of the two., Comment: 10 pages, 8 figures, accepted for publ. in A&A

We present multi-wavelength observations of the unassociated gamma-ray source 3FGL J2039.6-5618 detected by the Fermi Large Area Telescope. The source gamma-ray properties suggest that it is a pulsar, most likely a millisecond pulsar, for which neither radio nor $\gamma$-ray pulsations have been detected yet. We observed 3FGL J2039.6-5618 with XMM-Newton and discovered several candidate X-ray counterparts within/close to the gamma-ray error box. The brightest of these X-ray sources is variable with a period of 0.2245$\pm$0.0081 d. Its X-ray spectrum can be described by a power law with photon index $\Gamma_X =1.36\pm0.09$, and hydrogen column density $N_{\rm H} < 4 \times 10^{20}$ cm$^{-2}$, which gives an unabsorbed 0.3--10 keV X-ray flux of $1.02 \times 10^{-13}$ erg cm$^{-2}$ s$^{-1}$. Observations with the Gamma-Ray Burst Optical/Near-Infrared Detector (GROND) discovered an optical counterpart to this X-ray source, with a time-average magnitude $g'\sim 19.5$. The counterpart features a flux modulation with a period of 0.22748$\pm$0.00043 d that coincides, within the errors, with that of the X-ray source, confirming the association based on the positional coincidence. We interpret the observed X-ray/optical periodicity as the orbital period of a close binary system where one of the two members is a neutron star. The light curve profile of the companion star, with two asymmetric peaks, suggests that the optical emission comes from two regions at different temperatures on its tidally-distorted surface. Based upon its X-ray and optical properties, we consider this source as the most likely X-ray counterpart to 3FGL J2039.6-5618, which we propose to be a new redback system., Comment: 35 pages, 8 figures, accepted for publication on Astrophysical Journal