Inhibition of 2-oxoglutarate dependent oxygenases

2-Oxoglutarate (2OG) dependent oxygenases are ubiquitous iron enzymes that couple substrate oxidation to the conversion of 2OG to succinate and carbon dioxide. In humans their roles include collagen biosynthesis, fatty acid metabolism, DNA repair, RNA and chromatin modifications, and hypoxic sensing. Commercial applications of 2OG oxygenase inhibitors began with plant growth retardants, and now extend to a clinically used pharmaceutical compound for cardioprotection. Several 2OG oxygenases are now being targeted for therapeutic intervention for diseases including anaemia, inflammation and cancer. In this critical review, we describe studies on the inhibition of 2OG oxygenases, focusing on small molecules, and discuss the potential of 2OG oxygenases as therapeutic targets (295 references).     

Three-dimensional hierarchical structures for fog harvesting

Conventional fog-harvesting mechanisms are effectively pseudo-2D surface phenomena in terms of water droplet-plant interactions. In the case of the Cotula fallax plant, a unique hierarchical 3D arrangement formed by its leaves and the fine hairs covering them has been found to underpin the collection and retention of water droplets on the foliage for extended periods of time. The mechanisms of water capture and release as a function of the surface 3D structure and chemistry have been identified. Of particular note is that water is retained throughout the entirety of the plant and held within the foliage itself (rather than in localized regions). Individual plant hairs form matlike structures capable of supporting water droplets; these hairs wrap around water droplets in a 3D fashion to secure them via a fine nanoscale groove structure that prevents them from easily falling to the ground.     

Robust Self‐Assembled Monolayers of RuII and OsII Polypyridines on Gold Surfaces: Exploring New Potentials

Functional monolayers : Ru^II and Os^II bis‐terpyridine complexes have been attached through a piperazine‐supported dithiocarbamate to a gold substrate (see picture). The robust tether, and the favourable reduction in oxidation potential induced by the electron‐rich piperazine result in self‐assembled monolayers with excellent reversible redox behaviour and exceptional stability.

     

Structural development of free or coordinated 4'-(4-pyridyl)-2,2':6',2'-terpyridine ligands through N-alkylation: new strategies for metallamacrocycle formation

A series of N-alkylated derivatives of [Ru(pytpy)(2)]2+ (pytpy=4'-(4-pyridyl)-2,2':6',2'-terpyridine) has been synthesised and characterised. These include both model and functionalised complexes that complement previously reported iron(II) analogues. Reaction of [Ru(pytpy)(2)]2+ with bis[4-(bromomethyl)phenyl]methane leads to the formation of a [2+2] ruthenamacrocycle. Related ferramacrocycles could not be accessed by this route, and instead were prepared in two steps by first reacting bis[4-(bromomethyl)phenyl]methane or 4,4'-bis(bromomethyl)biphenyl with two equivalents of pytpy, and then treating the resulting bis(N-alkylated) product with iron(II) salts.     

Valence surface electronic states on Ge(001)

The optical, electrical, and chemical properties of semiconductor surfaces are largely determined by their electronic states close to the Fermi level (E{F}). We use scanning tunneling microscopy and density functional theory to clarify the fundamental nature of the ground state Ge(001) electronic structure near E{F}, and resolve previously contradictory photoemission and tunneling spectroscopy data. The highest energy occupied surface states were found to be exclusively back bond states, in contrast to the Si(001) surface, where dangling bond states also lie at the top of the valence band.     

A rod-like polymer containing (Ru(terpy)2) units prepared by electrochemical coupling of pendant thienyl moieties

A new rod-like coordination polymer consisting of (Ru-(terpy)2) motifs bridged by bithiophene units has been prepared by electrochemical polymerisation in acidic organic medium.     

Atomically precise placement of single dopants in si

We demonstrate the controlled incorporation of P dopant atoms in Si(001), presenting a new path toward the creation of atomic-scale electronic devices. We present a detailed study of the interaction of PH3 with Si(001) and show that it is possible to thermally incorporate P atoms into Si(001) below the H-desorption temperature. Control over the precise spatial location at which P atoms are incorporated was achieved using STM H lithography. We demonstrate the positioning of single P atoms in Si with approximately 1 nm accuracy and the creation of nanometer wide lines of incorporated P atoms.     

Towards hybrid silicon-organic molecular electronics: The stability of acetone on the Si(0 0 1) surface

We present the results of a combined study using scanning tunneling microscopy (STM) and density functional theory (DFT) of the interaction of acetone [(CH₃)₂CO] with the Si(0 0 1) surface. Three distinct adsorbate features were observed using atomic-resolution STM. One of the features appears as a bright protrusion located above a Si-Si dimer, while the other two are asymmetric about the dimer row and involve a second neighboring Si-Si dimer. One of the two asymmetric features has a protrusion located between the two dimers, while the other has a protrusion which is located at the site of a single dimer and exhibits a dimer sized depression on the adjacent dimer. DFT calculations have been performed for two structures; the four-membered ring structure and dissociation structure. Our calculations show that the bright single-dimer sized feature observed in the STM images could be attributed to either of these two calculated structures. However, neither of the two calculated structures can explain the appearance of the two-dimer wide asymmetric features observed in the experiment.