Morphological Characterization of the Human Calvarium in Relation to the Diploic and Cranial Thickness Utilizing X-Ray Computed Microtomography

When attempting to establish accurate models for the human diploe, micro-scale morphological differences in the four main areas of the calvaria could also be considered. In this study, X-ray computed microtomography (\u3bc-CT) images were analyzed in order to quantitatively characterize the micro- architecture of the human calvarium diploe. A bone specimen from each area of the skull (temporal, frontal, parietal and occipital) was extracted from a set of 5 human donors and each specimen was characterized in terms of density, specific surface area, trabecular thickness, trabecular spacing. The obtained results revealed that subject-individual structural differences could be related with the diploic as well as the total cranial thickness of the human skull bones. Some tendencies of dependency could also be made with respect to the age of the subject. A consideration of these individual variations can improve traditional models that assume equal conditions throughout the skul

Pre-plaque conformational changes in Alzheimer's disease-linked Aβ and APP

Reducing levels of the aggregation-prone Aβ peptide that accumulates in the brain with Alzheimer's disease (AD) has been a major target of experimental therapies. An alternative approach may be to stabilize the physiological conformation of Aβ. To date, the physiological state of Aβ in brain remains unclear, since the available methods used to process brain tissue for determination of Aβ aggregate conformation can in themselves alter the structure and/or composition of the aggregates. Here, using synchrotron-based Fourier transform infrared micro-spectroscopy, non-denaturing gel electrophoresis and conformational specific antibodies we show that the physiological conformations of Aβ and amyloid precursor protein (APP) in brain of transgenic mouse models of AD are altered before formation of amyloid plaques. Furthermore, focal Aβ aggregates in brain that precede amyloid plaque formation localize to synaptic terminals. These changes in the states of Aβ and APP that occur prior to plaque formation may provide novel targets for AD therapy

Preferential orientation of short chain vapor deposited polyaniline thin films on gold

Vapor deposited short chain polyaniline thin films were studied using angle-resolved photoemission spectroscopy. Films grown on two different substrates, oxidized Si surfaces and Au, show distinctly different properties. Some indication of preferential molecular orientation was observed for ultrathin films deposited on Au substrates, but not on the Si substrates with the native oxide surface. Clear indication of metallic character was observed for some of the polyaniline ultrathin films, consistent with recent theory suggesting that alignment of chains parallel with a metal substrate enhance metallicity