The Amyloid-β Peptide in Amyloid Formation Processes: Interactions with Blood Proteins and Naturally Occurring Metal Ions

This review describes interactions between the amyloid-β peptide (Aβ) involved in Alzheimer's disease (AD) and endogenous metal ions and proteins, with an emphasis on future potential drug therapies and targets. AD is characterised by loss of neurons, memory, and cognitive functions, and by formation of cerebral senile plaque deposits. These plaques consist mainly of aggregated Aβ peptides. AD pathology includes a) on the molecular level imbalanced concentrations of Aβ peptides and metal ions, and formation of amyloid structures, and b) on the physiological level a combination of inflammatory responses and oxidative stress effects causing neuronal death. Interestingly, certain blood proteins and metal ions can affect the Aβ amyloid aggregation process. These interactions are the topics of the present review. A deeper understanding of these interactions could facilitate new therapeutic strategies against AD. Previous therapeutic approaches and trials are also briefly described.     

Polymer/Nanocrystal Hybrid Solar Cells: Influence of Molecular Precursor Design on Film Nanomorphology,Charge Generation and Device Performance

In this work, molecular tuning of metal xanthate precursors is shown to have a marked effect on the heterojunction morphology of hybrid poly(3‐hexylthiophene‐2,5‐diyl) (P3HT)/CdS blends and, as a result, the photochemical processes and overall performance of in situ fabricated hybrid solar cells. A series of cadmium xanthate complexes is synthesized for use as in situ precursors to cadmium sulfide nanoparticles in hybrid P3HT/CdS solar cells. The formation of CdS domains is studied by simultaneous GIWAXS (grazing incidence wide‐angle X‐ray scattering) and GISAXS (grazing incidence small‐angle X‐ray scattering), revealing knowledge about crystal growth and the formation of different morphologies observed using TEM (transmission electron microscopy). These measurements show that there is a strong relationship between precursor structure and heterojunction nanomorphology. A combination of TAS (transient absorption spectroscopy) and photovoltaic device performance measurements is used to show the intricate balance required between charge photogeneration and percolated domains in order to effectively extract charges to maximize device power conversion efficiencies. This study presents a strong case for xanthate complexes as a useful route to designing optimal heterojunction morphologies for use in the emerging field of hybrid organic/inorganic solar cells, due to the fact that the nanomorphology can be tuned via careful design of these precursor materials.     

Polygon Laplacian Made Simple

The discrete Laplace-Beltrami operator for surface meshes is a fundamental building block for many (if not most) geometry processing algorithms. While Laplacians on triangle meshes have been researched intensively, yielding the cotangent discretization as the de-facto standard, the case of general polygon meshes has received much less attention. We present a discretization of the Laplace operator which is consistent with its expression as the composition of divergence and gradient operators, and is applicable to general polygon meshes, including meshes with non-convex, and even non-planar, faces. By virtually inserting a carefully placed point we implicitly refine each polygon into a triangle fan, but then hide the refinement within the matrix assembly. The resulting operator generalizes the cotangent Laplacian, inherits its advantages, and is empirically shown to be on par or even better than the recent polygon Laplacian of Alexa and Wardetzky [AW11] — while being simpler to compute.     

Knowledge,meaning and identity: Key characteristics of entrepreneurship in cultural and creative industries

This article introduces the Special Issue, “Varieties of entrepreneurship: Exploring whether, how and why cultural and creative entrepreneurship differs from other varieties”. The aim of the Special Issue is to contribute to a more nuanced understanding of how this particular variety of entrepreneurship emerges, is affected and develops over time. We present the three broad topics addressed in the Special Issue—knowledge, meaning and identity—and position them in the wider academic context of understanding value realization through entrepreneurship in the cultural and creative industries. The six articles presented in the Special Issue come from and combine different streams of literatures, yet jointly they gradually develop their own, hopefully complementary, interpretations, which provide inspiration for a promising agenda for further research.     

An automatic counter for autoradiographed cells in Petri dishes

A simple automatic counting device for cells on Petri dishes is described. The device is tested up to 1 × 10⁴ cells (0·01 m)^?2 and counts linearly without coincidence error. The counting time for each dish is c. 3– 4 min including the time required to place the dish in the apparatus.     

Synthesis of Al2O3/SiO2 nano‐nano composite ceramics under high pressure and its inverse Hall–Petch behavior

We report the synthesis of alumina/stishovite nano‐nano composite ceramics through a pressure‐induced dissociation in Al₂SiO₅ at a pressure of 15.6 GPa and temperatures of 1300°C‐1900°C. Stishovite is a high‐pressure polymorph of silica and the hardest known oxide at ambient conditions. The grain size of the composites increases with synthesis temperature from ~15 to ~750 nm. The composite is harder than alumina and the hardness increases with reducing grain size down to ~80 nm following a Hall–Petch relation. The maximum hardness with grain size of 81 nm is 23 ± 1 GPa. A softening with reducing grain size was observed below this grain size down to ~15 nm, which is known as inverse Hall–Petch behavior. The grain size dependence of the hardness might be explained by a composite model with a softer grain‐boundary phase.     

Filtration Behavior of Nanoparticulate Ceria Slurries

The influence of poly(acrylic acid) (PAA) concentration and molecular weight on the filtration behavior of CeO₂ slurries with 20 nm particle size was studied. Low-viscosity suspensions could be produced by adsorbing a monolayer of PAA that covered the nanoparticles. For all suspensions investigated, the cake permeability was lower than predicted by the Kozeny–Carman equation and decreased with increased filtration pressure because of the presence of a compressible PAA layer 3–5 nm thick on the surface of the particles. The permeability of the nanoparticulate cakes decreased with increased polymer addition because of clogging.