SUMMARY
Androgen receptor (AR) is reactivated in castration resistant prostate cancer (CRPC) through mechanisms including marked increases in AR gene expression. We identify an enhancer in the AR second intron contributing to increased AR expression at low androgen levels in CRPC. Moreover, at increased androgen levels the AR binds this site and represses AR gene expression through recruitment of lysine specific demethylase 1 (LSD1) and H3K4me1,2 demethylation. AR similarly represses expression of multiple genes mediating androgen synthesis, DNA synthesis and proliferation, while stimulating genes mediating lipid and protein biosynthesis. Androgen levels in CRPC appear adequate to stimulate AR activity on enhancer elements, but not suppressor elements, resulting in increased expression of AR and AR repressed genes that contribute to cellular proliferation.
Forming core-shell and alloy structures offers generally two ways to design efficient Pt-based catalysts for oxygen reduction reaction (ORR). Here, we combined these two strategies and invented a versatile aqueous route to synthesize octahedral Pd@Pt1.8Ni core-shell nanocrystals. The Pt/Ni atomic ratios in the resultant shells can be varied from 0.6 to 1.8, simply by changing the amounts of Pt and Ni precursors, with the other conditions unchanged. Experimental studies showed that the mass activities of as-prepared catalysts were 5 times higher than that of the commercial Pt/C. We believe that the ultrathin PtNi shells enclosed by {111} facets made it possible to reduce the Pt content while retaining the catalytic activity toward ORR. This strategy may be extended to the preparation of other multimetallic nanocrystals with shaped and ultrathin alloy shells, which is conducive to design highly active catalysts.
Recently, metal nanoframes have received increased attention due to their unique spatial and physicochemical, e.g., catalytic and plasmonic properties. So far, a variety of synthetic procedures have been developed to fabricate metal nanoframes with different shapes, sizes and compositions. Typical synthesis of metal nanoframes involves two stages: 1) formation of solid nanocrystals and 2) hollowing out the interiors and side faces. In this review, solution-phase synthetic strategies are summarized, based on galvanic replacement reactions, oxidative etching, the Kirkendall effect, electrodeposition, and template-assisted growth, as well as one-pot synthesis. Their potential applications in catalysis and optical sensing are overviewed as well.
Condensed matter systems have now become a fertile ground to discover emerging topological quasiparticles with symmetry protected modes. While many studies have focused on fermionic excitations, the same conceptual framework can also be applied to bosons yielding new types of topological states. Motivated by Zhang et al.'s recent theoretical prediction of double Weyl phonons in transition metal monosilicides [Phys. Rev. Lett. 120, 016401 (2018)PRLTAO0031-900710.1103/PhysRevLett.120.016401], we directly measure the phonon dispersion in parity-breaking FeSi using inelastic x-ray scattering. By comparing the experimental data with theoretical calculations, we make the first observation of double Weyl points in FeSi, which will be an ideal material to explore emerging bosonic excitations and its topologically nontrivial properties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.