Identification of a non-thermal X-ray burst with the Galactic magnetar SGR J1935+2154 and a fast radio burst using

We present the X-ray timing results of the new black hole candidate (BHC) MAXI J1535-571 during its 2017 outburst from Hard X-ray Modulation Telescope (Insight -HXMT) observations taken from 2017 September 6 to 23. Following the definitions given by Belloni (2010), we find that the source exhibits state transitions from Low/Hard state (LHS) to Hard Intermediate state (HIMS) and eventually to Soft Intermediate state (SIMS). Quasi-periodic oscillations (QPOs) are found in the intermediate states, which suggest different types of QPOs. With the large effective area of Insight -HXMT at high energies, we are able to present the energy dependence of the QPO amplitude and centroid frequency up to 100 keV which is rarely explored by previous satellites. We also find that the phase lag at the type-C QPOs centroid frequency is negative (soft lags) and strongly correlated with the centroid frequency. By assuming a geometrical origin of type-C QPOs, the source is consistent with being a high inclination system.

The environment of bone marrow mesenchymal stem cells (MSCs) is hypoxic, which plays an important role in maintaining their self-renewal potential and undifferentiated state. MSCs have been proven to possess immunomodulatory properties and have been used clinically to treat autoimmune diseases. Here, we tested the effects of hypoxia on the immunomodulatory properties of MSCs and examined its possible underlying mechanisms. We found that hypoxic stimulation promoted the immunomodulatory properties of human gingiva-derived mesenchymal stem cells (hGMSCs) by enhancing the suppressive effects of hGMSCs on peripheral blood mononuclear cells (PBMCs). The proliferation of PBMCs was significantly inhibited, while the apoptosis of PBMCs was increased, which was associated with the Fas ligand (FasL) expression of hGMSCs. The in vivo study showed that systemically infused hGMSCs could enhance skin wound repair, and 24-h hypoxic stimulation significantly promoted the reparative capacity of hGMSCs. For mechanism, hGMSC treatment inhibited the local inflammation of injured skin by suppressing the inflammatory cells, reducing the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), and increasing anti-inflammatory cytokine interleukin-10 (IL-10), which was promoted by hypoxia. Hypoxia preconditioning may be a good optimizing method to promote the potential of MSCs for the future cell-based therapy.

We study the evolution of the temporal properties of MAXIJ1820+070 during the 2018 outburst in its hard state from MJD58,190 to 58,289 with Insight-HXMT in a broad energy band 1-150 keV. We find different behaviors of the hardness ratio, the fractional rms and time lag before and after MJD58,257, suggesting a transition occurred around this point. The observed time lags between the soft photons in the 1-5 keV band and the hard photons in higher energy bands, up to 150 keV, are frequency-dependent: the time lags in the low-frequency range, 2-10mHz, are both soft and hard lags with a timescale of dozens of seconds but without a clear trend along the outburst; the time lags in the high-frequency range, 1-10Hz, are only hard lags with a timescale of tens of milliseconds; they first increase until around MJD58,257 and decrease after this date. The high-frequency time lags are significantly correlated to the photon index derived from the fit to the quasi-simultaneous NICER spectrum in the 1-10 keV band. This result is qualitatively consistent with a model in which the high-frequency time lags are produced by Comptonization in a jet.Unified Astronomy Thesaurus concepts: Black holes (162); Compact objects (288); Low-mass x-ray binary stars (939)