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Acting Neurodevelopmental and Neuropsychiatric Conditions with Astrocytes Based on Human-Induced Pluripotent Stem Tissues.
Two-dimensional materials (2Dm) offer a unique insight into the world of quantum mechanics including van der Waals (vdWs) interactions, exciton dynamics and various other nanoscale phenomena. 2Dm are a growing family consisting of graphene, hexagonal-Boron Nitride (h-BN), transition metal dichalcogenides (TMDs), monochalcogenides (MNs), black phosphorus (BP), MXenes and 2D organic crystals such as small molecules (e.g., pentacene, C8 BTBT, perylene derivatives, etc.) and polymers (e.g., COF and MOF, etc.). They exhibit unique mechanical, electrical, optical and optoelectronic properties that are highly enhanced as the surface to volume ratio increases, resulting from the transition of bulk to the few- to mono- layer limit. Such unique attributes include the manifestation of highly tuneable bandgap semiconductors, reduced dielectric screening, highly enhanced many body interactions, the ability to withstand high strains, ferromagnetism, piezoelectric and flexoelectric effects. see more Using 2Dm for mechanical resonators has become a promising field in nanoelectromechanical systems (NEMS) for applications involving sensors and condensed matter physics investigations. 2Dm NEMS resonators react with their environment, exhibit highly nonlinear behaviour from tension induced stiffening effects and couple different physics domains. The small size and high stiffness of these devices possess the potential of highly enhanced force sensitivities for measuring a wide variety of un-investigated physical forces. This review highlights current research in 2Dm NEMS resonators from fundamental physics and an applications standpoint, as well as presenting future possibilities using these devices.A protocol for the accurate computation of electron transfer (ET) potentials from ab initio and density functional theory (DFT) calculations is described. The method relies on experimental pKa values, which can be measured accurately, to compute a computational setup dependent effective absolute potential. The effective absolute potentials calculated using this protocol display strong variations between the different computational setups and deviate in several cases significantly from the "generally accepted" value of 4.28 V. The most accurate estimate, obtained from CCSD(T)/aug-ccpvqz, indicates an absolute potential of 4.14 V for the normal hydrogen electrode (nhe) in water. Using the effective absolute potential in combination with CCSD(T) and a moderately sized basis, we are able to predict ET potentials accurately for a test set of small organic molecules (σ = 0.13 V). Similarly we find the effective absolute potential method to perform equally good or better for all considered DFT functionals compared to using one of the literature values for the absolute potential. For, M06-2X, which comprises the most accurate DFT method, standard deviation of 0.18 V is obtained. This improved performance is a result of using the most appropriate effective absolute potential for a given method.Graphdiyne (GDY) is a newly discovered 2D carbon allotrope, widely used as a support for heterogeneous transition metal catalysts. We investigated the binding, electronic structure, diffusion mechanisms and aggregation possibilities of mono-dispersed Ir atoms on GDY by extensive first-principles based calculations. The binding of Ir atoms on GDY can be up to -4.84 eV when the Ir atom is trapped in the C18 ring interacting with 2 adjacent diyne moieties connected to the same benzene ring. The diffusion of Ir atoms along the diyne moiety is quite facile with barriers less than 0.89 eV; the highest barrier for Ir diffusion into the C18 ring is 0.10 eV, whereas inter/intra-C18 ring diffusion is limited by a barrier of 1.64 eV, thereby leading to a dominant population of Ir atoms trapped in the C18 rings. The electronic structure of small Ir clusters was also investigated. Though the formation of Ir-Ir bonds is exothermic and thermodynamically favorable, which may, in some circumstances, even overwhelm the formation of interfacial Ir-C bonds, aggregation of Ir atoms into clusters is limited by the high energy barrier of inter/intra C18 ring diffusion. We propose that aggregation of Ir atoms into clusters may be initiated by shifting the diffusion thermodynamics deliberately and expect the finding may help to understand the stability and evolution of GDY based single atom catalysts.Correction for 'Salt parameterization can drastically affect the results from classical atomistic simulations of water desalination by MoS2 nanopores' by João P. K. Abal et al., Phys. Chem. Chem. Phys., 2020, 22, 11053-11061, DOI 10.1039/d0cp00484g.π-Orbital bonding plays an important role not only in traditional molecular science and solid-state chemistry but also in modern quantum physics and materials, such as the relativistic Dirac states formed by bonding and antibonding π-bands in graphene. Here, we disclose an interesting manifestation of π-orbitals in forming the Yin-Yang Kagome bands, which host potentially a range of exotic quantum phenomena. Based on first-principles calculations and tight-binding orbital analyses, we show that the frontier π2- and π3-orbitals in anilato-based metal-organic frameworks form concurrently a conduction and valence set of Kagome bands, respectively, but with opposite signs of lattice hopping to constitute a pair of enantiomorphic Yin and Yang Kagome bands, as recently proposed in a diatomic Kagome lattice. The twisted configuration of neighboring benzene-derived organic ligands bridged by an octahedrally O-coordinated metal ion is found to play a critical role in creating the opposite sign of lattice hopping for the π2- versus π3-orbitals. Our finding affords a new material platform to study π-orbital originated quantum chemistry and physics.An efficient iron-catalyzed carbonylative cyclization of γ,δ-unsaturated aromatic oxime esters with amines has been developed. A range of functionalized β-homoproline amide derivatives were prepared via an iminyl radical-mediated intramolecular 1,5-cyclization followed by carbon radical-triggered intermolecular carbonylation. Examples on further transforming the obtained product were successfully discussed as well.
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