Fitzgeraldboysen2103

Organometallic sandwich complexes, composed of cyclic hydrocarbon ligands and transition-metal atoms, display unique physical and chemical properties. In this work, the electronic and spin transport properties of one-dimensional (1D) VBz2 ligand bimetallic sandwich complexes, VBz2-TM (TM = Cr, Mn, and Fe), are systematically investigated using density functional theory and nonequilibrium Green's function method. The results show that all the 1D infinite molecular wires [(VBz2)TM]∞ (TM = Cr-Fe) are found to be thermodynamically stable with high binding energies (∼1.0-3.45 eV). In particular, they are predicted to be ferromagnetic half metals. Moreover, the I-V curves exhibit negative differential resistance for one, two, and three VBz2-TM wires at TM = Cr, Mn, and Fe, respectively, which is of great significance for certain electronic applications. Our findings strongly suggest that the benzene ligand bimetallic sandwich molecular wires are good candidates for potential electronics and spintronics. Copyright © 2020 American Chemical Society.Magnetic fields generated by the nanosolenoids based on the (5, 3) and (10,7) gold nanotubes (AuNTs) 12-600 Å long with numbers of Au atoms 20-2000 are calculated. The electron energy levels of the finite length tubules were determined using the linearized augmented cylindrical waves method with Born-von Karman cyclic boundary conditions and on account of a helical symmetry of the AuNTs. Using these data, the numbers of conducting channels N F and the low-temperature ballistic electron currents in the finite AuNTs are determined, and finally, the magnetic fields B of the gold nanosolenoids are obtained. Due to the increase in the number of conduction channels with the increase in the length of the tubes, the internal magnetic field gradually increases from 1.6 T/V in a tubule with L = 12 Å up to 12 T/V in a tube with L = 600 Å, slowly approaching the magnetic field of 14 T/V of the infinite (5, 3) AuNT. At a distance of 5 Å from the ends of the tubes (near z = L/2 - 5 Å), this field decreases rapidly, halving at z = L/2 and almost zeroing near z = L/2 + 5 Å. The field from the outside of the tubes is weak but not zero as in the infinite tubule. It is minimal at z = 0 and reaches a maximum at the edge of the AuNTs, where it is about 3-4 times less than the internal field. These results pave the way for a more realistic design of the nanosolenoids. Copyright © 2020 American Chemical Society.Biosynthesized nanoparticles are gaining attention because of biologically active plant secondary metabolites that help in green synthesis and also due to their unique biological applications. This study reports a facile, ecofriendly, reliable, and cost-effective synthesis of silver nanoparticles using the aqueous leaf extract of Cucumis prophetarum (C. prophetarum) and their antibacterial and antiproliferative activity. Silver nanoparticles were biosynthesized using the aqueous leaf extract of C. prophetarum, which acted as a reducing and capping agent. The biosynthesized C. prophetarum silver nanoparticles (Cp-AgNPs) were characterized using different techniques, such as UV-visible spectroscopy, dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX). Phytochemical analysis was performed to determine the phytochemicals responsible for the reduction and capping of the biosynthesizedth good antibacterial activity and antiproliferative potential against selected cancer cell lines. The biosynthesized C. prophetarum AgNPs can be further exploited as a potential candidate for antioxidant, antibacterial, and anticancer agents. Copyright © 2020 American Chemical Society.A method for conjugating cholesterol to peptide ligands through non-disperse polyethylene glycol (ND-PEG) through a non-hydrolysable linkage is described. The iterative addition of tetraethylene glycol macrocyclic sulfate to cholesterol (Chol) renders a family of highly pure well-defined Chol-PEG compounds with different PEG lengths from 4 up to 20 ethylene oxide units, stably linked through an ether bond. Mivebresib inhibitor The conjugation of these Chol-PEG compounds to the cyclic (RGDfK) peptide though Lys5 side chains generates different lengths of Chol-PEG-RGD conjugates that retain the oligomer purity of the precursors, as analysis by HRMS and NMR has shown. Other derivatives were synthesized with similar results, such as Chol-PEG-OCH3 and Chol-PEG conjugated to glutathione and Tf1 peptides through maleimide-thiol chemoselective ligation. This method allows the systematic synthesis of highly pure uniform stable Chol-PEGs, circumventing the use of activation groups on each elongation step and thus reducing the number of synthesis steps. Copyright © 2020 American Chemical Society.For the regeneration or creation of functional tissues, biodegradable biomaterials including polylactic acid (PLA) are widely preferred. Modifications of the material surface are quite common to improve cell-material interactions and thereby support the biological outcome. Typical approaches include a wet chemical treatment with mostly hazardous substances or a functionalization with plasma. In the present study, gas-phase fluorination was applied to functionalize the PLA surfaces in a simple and one-step process. The biological response including biocompatibility, cell adhesion, cell spreading, and proliferation was analyzed in cell culture experiments with fibroblasts L929 and correlated with changes in the surface properties. Surface characterization methods including surface energy and isoelectric point measurements, X-ray photoelectron spectroscopy, and atomic force microscopy were applied to identify the effects of fluorination on PLA. Gas-phase fluorination causes the formation of C-F bonds in the PLA backbone, which induce a shift to a more hydrophilic and polar surface. The slightly negatively charged surface dramatically improves cell adhesion and spreading of cells on the PLA even with low fluorine content. The results indicate that this improved biological response is protein- but not integrin-dependent. Gas-phase fluorination is therefore an efficient technique to improve cellular response to biomaterial surfaces without losing cytocompatibility. Copyright © 2020 American Chemical Society.