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Neutrino losses play a crucial role in the evolution of massive stars. We study the neutrino luminosity of stars ranging from 20 to 90  |$\rm M_{\odot }$| from Zero Age Main Sequence to Fe Core Collapse (FeCC) with different rotation and metallicity in a neutrino Hertzsprung–Russell diagram. In our simulations, we consider |$\rm \omega /\omega _{crit}= 0$| and 0.7 to represent non-rotation and high rotation, respectively, and set the metallicities to 0.014, 0.001, and 0.0001. During hydrogen burning stages, neutrino luminosity primarily originates from CNO cycle, and increases with higher stellar mass while decreasing with increasing metallicity. For the high metallicity models (Z  = 0.014) during the helium burning stage, the reduction of the hydrogen envelope caused by a larger mass loss rate leads to a gradual decrease in neutrino luminosity. The rapid rotation results in extra mixing inside massive stars, which increases the neutrino luminosity during main sequence, while decreases the neutrino luminosity during helium burning phase. Simultaneously, the rapid rotation also increases CO core mass, which enhances the neutrino luminosity during C and O burning phase. We also investigate the effect of neutrino magnetic moment (NMM) on the massive stars. We find that the energy loss caused by the NMM does not have effects on the evolutionary destiny of massive stars, and it does not significant change the compactness at the time of FeCC. [ABSTRACT FROM AUTHOR]

The actinides, such as the uranium (U) element, are typically synthesized through the rapid neutron-capture process (r-process), which can occur in core-collapse supernovae or double neutron star mergers. There exist nine r-process giant stars exhibiting conspicuous U abundances, commonly referred to as U-rich giants. However, the origins of these U-rich giants remain ambiguous. We propose an alternative formation scenario for these U-rich giants whereby a red giant (RG) engulfs an Earth-like planet. To approximate the process of an RG engulfing an Earth-like planet, we employ an accretion model wherein the RG assimilates materials from said planet. Our findings demonstrate that this engulfment event can considerably enhance the presence of heavy elements originating from Earth-like planets on the surfaces of very metal-poor stars (Z  = 0.00001), while its impact on solar-metallicity stars is comparatively modest. Importantly, the structural and evolutionary properties of both very metal-poor and solar-metallicity stars remain largely unaffected. Notably, our engulfment model effectively accounts for the observed U abundances in known U-rich giants. Furthermore, the evolutionary trajectories of U abundances on the surfaces of RGs subsequent to the engulfment of Earth-like planets encompass all known U-rich giants. Therefore, it is plausible that U-rich giants are formed when an RG engulfs an Earth-like planet. [ABSTRACT FROM AUTHOR]

The function ofmicroRNA-34a(miR-34a) in transdifferentiation of glioma stem cells (GSCs) into vascular endothelial cells (VECs) was explored by focusing on Notch ligand Delta-like 1 (Dll1).MiR-34amimics was transfected into CD133 + glioma cell U251. The angiogenesis feature ofmiR-34atransfected U251 cells was investigated and the expressions of CD31, CD34, Vwf, Notch 1, and Dll1 were quantified. Length of branching vessel-like structures in themiR-34atransfected U251 cells was significantly higher than control cells. The VEC feature ofmiR-34aoverexpressed U251 cells was further confirmed by the expressions of CD31, CD34, and vWF. Transfection ofmiR-34adecreased the expression of Notch 1 and Dll1. Furthermore, themiR-34aoverexpression-enhanced tube formation of GSCs was suppressed when the decreased expression of Dll1 was restored. The current study highlighted the potential ofmiR-34aas an inducer in GSCs’ transdifferentiation into VECs by targeting Dll1. Up-regulation of miR-34a induced transdifferentiation of CD133+ U251 cells into VECs [ABSTRACT FROM PUBLISHER]