First-principles study on h-BSi3 sheet as a promising high-performance anode for sodium-ion batteries.

Seeking cheap, efficient and sustainable alternatives to lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) has emerged as a realm of research, due to the abundance of Na in the earth's crust. We have investigated the relative performance of novel intrinsically metallic h-BSi3 (BS) sheet as an anode for SIBs, compared to LIBs, through Density Functional Theory studies. Our calculations show that BS has higher chemisorption interactions with Na than Li atoms while drawing substantial electron densities from both, turning them into cations. BS is able to reach a high specific capacity of 1127.62 mA h g-1 for Na, while only as half of that for Li, at ambient temperatures ranging 300-600 K. The moderate sodiation (0.77 V) and lithiation (0.79 V) voltages facilitate BS to prevent the SEI layer formation, metal plating and harmful dendrite growth and to maintain good energy density. BS retains good electronic and ionic conductivities after hosting both Na and Li adatoms, while the former diffuses with about as half the barriers as those of the latter, supporting faster charge/discharge rate and greater preservation of storage capacities in high current densities when BS is used as an anode in SIBs. Na adsorptions cause relatively lower structural deformations to BS, and refrain from forming clusters, leading to good cyclic stability. The superior electrochemical performance of Na, thus, makes BS a potential anode material for SIBs.

Enhancer variants reveal a conserved transcription factor network governed by PU.1 during osteoclast differentiation.

Genome-wide association studies (GWASs) have been instrumental in understanding complex phenotypic traits. However, they have rarely been used to understand lineage-specific pathways and functions that contribute to the trait. In this study, by integrating lineage-specific enhancers from mesenchymal and myeloid compartments with bone mineral density loci, we were able to segregate osteoblast- and osteoclast (OC)-specific functions. Specifically, in OCs, a PU.1-dependent transcription factor (TF) network was revealed. Deletion of PU.1 in OCs in mice resulted in severe osteopetrosis. Functional genomic analysis indicated PU.1 and MITF orchestrated a TF network essential for OC differentiation. Several of these TFs were regulated by cooperative binding of PU.1 with BRD4 to form superenhancers. Further, PU.1 is essential for conformational changes in the superenhancer region of Nfatc1. In summary, our study demonstrates that combining GWASs with genome-wide binding studies and model organisms could decipher lineage-specific pathways contributing to complex disease states.

Finite jellium models. I. Restricted Hartree-Fock calculations.

Restricted Hartree-Fock calculations have been performed on the Fermi configurations of n electrons confined within a cube. The self-consistent-field orbitals have been expanded in a basis of N particle-in-a-box wave functions. The difficult one- and two-electron integrals have been reduced to a small set of canonical integrals that are calculated accurately using quadrature. The total energy and exchange energy per particle converge smoothly toward their limiting values as n increases; the highest occupied molecular orbital-lowest unoccupied molecular orbital gap and Dirac coefficient converge erratically. However, the convergence in all cases is slow.