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

A next-generation liquid xenon observatory for dark matter and neutrino physics

The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for weakly interacting massive particles, while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector

Porous monoliths synthesized via polymerization of styrene and divinyl benzene in nonaqueous deep-eutectic solvent-based HIPEs

CONACYT [181678]; Catedras CONACYT programs; CONACYT through Estancias postdoctorales en el extranjero; [MAT2012-34811

The value of Tc-99m tetrofosmin in the imaging of pituitary adenomas

Aim: Magnetic resonance imaging (MRI) and computerized tomography (CT) are used in the diagnosis and follow-up of pituitary adenoma cases. Sometimes, these methods cannot display the post-operative residual tissue. It has been shown that some radionuclides were taken up by the pituitary adenomas. The aim of this study was to evaluate the uptake of the technetium-99m (Tc-99m) tetrofosmin (TF) in the pituitary adenoma and normal pituitary tissue and assess the ability of Tc-99m TF to predict tumor malignancy in pituitary gland. Methods: The patients with pituitary adenoma (7 invasive and 8 non-invasive) were compared with control group (no. 13). Single-photon emission computed tomography (SPECT) imaging of pituitary gland was performed in both groups. Tc-99m uptake indices were evaluated statistically with the use of Mann-Whitney U test. Results: The average tetrofosmin uptake index of pituitary adenoma is 2.44 +/- 1.54 for the patients and 1.69 +/- 0.71 for the control group. Any significant difference was not observed between the groups (p 0.3). The average index was calculated as 3.04 +/- 2.15 for invasive adenomas and 1.92 +/- 0.33 for the non-invasive group, and there was no significant difference between the two groups regarding uptake of the agent (p 0.53). Furthermore, it was determined that the invasive and non-invasive adenomas displayed an uptake of Tc-99m TF similar to normal pituitary tissue. Conclusions: Since the pituitary adenoma and normal pituitary tissue gave similar results regarding Tc-99m TF uptake, it was concluded that this agent would not be useful in the diagnosis of pituitary adenoma