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Abstract: Objective: To investigate the effect of estrogen receptor beta (ERβ) on osteoblastic differentiation function of human periodontal ligament (hPDL) cells by measuring the alkaline phosphatase (ALP) activity and the production of osteocalcin (OCN) in vitro. Design: We employed a short interfering RNA (siRNA) technique to inhibit ERβ expression in hPDL cells; the cells were cultured with a saturating concentration of 17β-estradiol (10−7 M). ALP activity was analysed by colorimetric assay using ALP kit and the amount of OCN was assessed by osteocalcin ELISA kit. Results: It was shown that estradiol significantly enhanced the ALP activity and the production of OCN in hPDL cells. However, the ALP activity and the production of OCN in hPDL-siERβ cells were not significantly changed after estradiol treatment. Conclusions: These results indicate that ERβ may play important roles in estrogen-induced effects on osteoblastic differentiation function of PDL cells and estrogen influences the bone formation capacity of PDL cells mainly via ERβ. [Copyright &y& Elsevier]

Nanoporous carbon foams (CFs), which are formed by the interconnection of graphene stripes and sp 3 hybridized carbon junctions, have attracted great attention owing to their potential applications. However, the structural diversity makes it hard to experimentally gain accurate structural information. By performing first-principles calculations, we propose nanoporous CFs, which are based on the sixfold-wing graphene nanoribbons (SWGNRs), and systematically study their stabilities, mechanical properties, and electronic properties. The results show that the new CF networks are chemically, dynamically, and mechanically stable, and the stabilities are enhanced as the pore size is increased. More importantly, the CFs well-inherit the size-dependent electronic properties of GNRs, and overcome the instabilities and edge effects of GNRs. The superior structural, mechanical, and electronic properties make the γ-CFs potential candidates for application in electronic and thermoelectric devices, hydrogen and energy storage, and molecular screening. [ABSTRACT FROM AUTHOR]

Carbon foam nanowires (CFNWs), which are mixed sp 2 / sp 3 hybridized microporous one-dimensional structures, have received much attention in the past two decades. In the present work, first-principle and molecular dynamics (MD) calculations revealed that the surface states causes the metallicity of CFNWs with small size, which demonstrates a Dirac cone-like dispersion near Γ in the Brillouin zone, while the metallicity of large size CFNWs are caused by the bulk states. However, hydrogenation of the CFNWs turns the metallicity into semiconducting with an expansion of the band gap by 0.15–1.5 eV. Interestingly, the metallicity is enhanced when hydrogenation on the top of the CFNWs. Atomic cohesive energy analysis suggests that the CFNWs are energetically favorable up to its melting point at 2200 K. When heating above the melting point, CFNWs transit into multi-walled carbon nanotubes (MWCNTs), agreeing with experimental observations. These findings indicate the feasibility of metallic-semiconductive transition, which have potential applications in nanoscale devices, hydrogen storage and the preparation of MWCNTs. [ABSTRACT FROM AUTHOR]

The molecule zinc methyl phenalenyl (ZMP), which is a neutral planar phenalenyl-based molecule, has been successfully synthesized experimentally, and large magnetic anisotropy was demonstrated when it is grown on the ferromagnetic metal surface [K. V. Raman et al. Nature, 2013, 493 , 509]. Here, by using nonequilibrium Green's functions combined with the density functional theory, we investigate the electronic transport properties in the ZMP molecule coupled to graphene nanoribbon (GNR) leads. When the ZMP molecule is linked to zigzag GNR (ZGNR) electrodes, perfect spin-filtering effect and large spin-rectifying effect are found. And when the ZMP molecule is coupled to armchair GNR (AGNR) electrodes, rectifying effect is obtained and the rectifying directions can be manipulated by substituting the hydrogen atoms at the edge of ZMP molecule with atoms oxygen or nitrogen. The above interesting properties can be used for the next generation nanoscale device. Analyses are proposed for these phenomena. [ABSTRACT FROM AUTHOR]