P roteins adopt an amazing array of sequence-dependent structures that enable them to perform the many chemical functions critical to life. Over the past decade, however, it has become clear that many different protein sequences can also form misfolded, insoluble aggregates known as amyloid fibrils, with common structural elements. Amyloid fibrils appear to be involved in a number of diseases, ...

We have investigated doped and undoped layers of microcrystalline silicon prepared by hot wire chemical vapour deposition optically, electrically and by means of transmission electron microscopy. Beside needlelike crystals grown perpendicular to the substrate’s surface all of the layers contained a noncrystalline phase with a volume fraction between 4% and 25%. A high oxygen content of several ...

We link the thermodynamics of colloidal suspensions to the statistics of regular and random packings. Random close packing has defied a rigorous definition yet, in three dimensions, there is near universal agreement on the volume fraction at which it occurs. We conjecture that the common value of phi{rcp} approximately 0.64 arises from a divergence in the rate at which accessible states disappe...

In this paper, we show that a noncrystalline but ordered smectic-like phase exists above the bulk-melting temperature (T(m)) at poly(n-alkyl acrylates)-air interface. The surface ordered phase is one monolayer thick and undergoes a sharp transition from order to disorder 10 degrees C above T(m) for n=22. The presence of a surface phase that does not exist in the bulk has important implications ...

Combined experimental and computational studies show that, upon reducing the diameter of Pt nanoparticles down to 1 nm, a collapse in the crystalline structure occurs spontaneously and the thus-induced quantum size effect causes a decline in the catalytic activity toward H2 electrooxidation. Platinum has been playing a vital role in heterogeneous catalysis, especially for low-temperature fuel c...