Colchicine reduces the activation of NLRP3 inflammasome in COVID-19 patients.

OBJECTIVE: To evaluate whether colchicine treatment was associated with the inhibition of NLRP3 inflammasome activation in patients with COVID-19. METHODS: We present a post hoc analysis from a double-blinded placebo-controlled randomized clinical trial (RCT) on the effect of colchicine for the treatment of COVID-19. Serum levels of NOD-like receptor protein 3 (NLRP3) inflammasome products-active caspase-1 (Casp1p20), IL-1ß, and IL-18-were assessed at enrollment and after 48-72 h of treatment in patients receiving standard-of-care (SOC) plus placebo vs. those receiving SOC plus colchicine. The colchicine regimen was 0.5 mg tid for 5 days, followed by 0.5 mg bid for another 5 days. RESULTS: Thirty-six patients received SOC plus colchicine, and thirty-six received SOC plus placebo. Colchicine reduced the need for supplemental oxygen and the length of hospitalization. On Days 2-3, colchicine lowered the serum levels of Casp1p20 and IL-18, but not IL-1ß. CONCLUSION: Treatment with colchicine inhibited the activation of the NLRP3 inflammasome, an event triggering the 'cytokine storm' in COVID-19. TRIAL REGISTRATION NUMBERS: RBR-8jyhxh.

Results of a Search for Sub-GeV Dark Matter Using 2013 LUX Data.

The scattering of dark matter (DM) particles with sub-GeV masses off nuclei is difficult to detect using liquid xenon-based DM search instruments because the energy transfer during nuclear recoils is smaller than the typical detector threshold. However, the tree-level DM-nucleus scattering diagram can be accompanied by simultaneous emission of a bremsstrahlung photon or a so-called "Migdal" electron. These provide an electron recoil component to the experimental signature at higher energies than the corresponding nuclear recoil. The presence of this signature allows liquid xenon detectors to use both the scintillation and the ionization signals in the analysis where the nuclear recoil signal would not be otherwise visible. We report constraints on spin-independent DM-nucleon scattering for DM particles with masses of 0.4-5 GeV/c^{2} using 1.4×10^{4} kg day of search exposure from the 2013 data from the Large Underground Xenon (LUX) experiment for four different classes of mediators. This analysis extends the reach of liquid xenon-based DM search instruments to lower DM masses than has been achieved previously.

Limits on the spin-dependent WIMP-nucleon cross sections from the first science run of the ZEPLIN-III experiment.

We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter weakly interacting massive particles based at the Boulby mine. Analysis of approximately 450 kg x days fiducial exposure allow us to place a 90%-confidence upper limit on the pure WIMP-neutron cross section of sigma(n)=1.9x10(-2) pb at 55 GeV/c(2) WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn charge-dependent nucleon-nucleon potential were used for the odd-neutron isotopes 129Xe and 131Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction could be much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of approximately 2.