Brain site-specific proteome changes in aging-related dementia

This study is aimed at gaining insights into the brain site-specific proteomic senescence signature while comparing physiologically aged brains with aging-related dementia brains (for example, Alzheimer''s disease (AD)). Our study of proteomic differences within the hippocampus (Hp), parietal cortex (pCx) and cerebellum (Cb) could provide conceptual insights into the molecular mechanisms involved in aging-related neurodegeneration. Using an isobaric tag for relative and absolute quantitation (iTRAQ)-based two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D-LC-MS/MS) brain site-specific proteomic strategy, we identified 950 proteins in the Hp, pCx and Cb of AD brains. Of these proteins, 31 were significantly altered. Most of the differentially regulated proteins are involved in molecular transport, nervous system development, synaptic plasticity and apoptosis. Particularly, proteins such as Gelsolin (GSN), Tenascin-R (TNR) and AHNAK could potentially act as novel biomarkers of aging-related neurodegeneration. Importantly, our Ingenuity Pathway Analysis (IPA)-based network analysis further revealed ubiquitin C (UBC) as a pivotal protein to interact with diverse AD-associated pathophysiological molecular factors and suggests the reduced ubiquitin proteasome degradation system (UPS) as one of the causative factors of AD.     

The FT-IR spectra of pyridine and pyridine-d5

The high-resolution (0.06 cm^?1) FT-IR spectra of pyridine and pyridine-d₅ at various path lengths (up to 10 m) have been obtained. These spectra reveal many new features that were not observed before. For example, the observation of many difference bands allows accurate determination of vibrational term values of some inactive and/or weak fundamental vibrations. The five CH stretching modes have been resolved for the first time. Frequency accuracy and internal consistency (since only high-resolution FT-IR data are used) are essential to the present analysis which provides accurate, isolated molecule term values for most of the fundamental vibrations of pyridine and pyridine-d₅. These results will be useful for more accurate force field analyses and serve as a guide for future, higher-resolution rotational studies for which the perturbations can now be predicted with more certainty.     

Grafting of nanoporous alumina membranes and films with organic acids

In this study, direct surface grafting of nanoporous alumina membranes and glass‐supported alumina films was carried out with three different fluorinated organic acids: trifluoroacetic acid, perfluoropentanoic acid and 2,3,4,5,6‐pentafluorobenzoic acid. Elemental surface composition and chemical environment of alumina were investigated using X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Alumina surfaces grafted with fluoro‐organic acids exhibited increased hydrophobic properties compared to ungrafted surfaces when measured using goniometry and atomic force microscopy (AFM). This work describes the evidence for surface chemical modification of alumina using direct reaction with organic acids. An AFM study of the adsorption of the immunoglobulin G (IgG) molecules on the fluoro‐organic‐acid‐grafted surfaces is reported. The results show that an ordered arrangement of immunoglobulin G structures with in‐filling of pores could be achieved only on the more hydrophobic fluoro‐organic‐acid‐grafted alumina membranes. Copyright © 2007 John Wiley & Sons, Ltd.     

The glass-molding process for planar-integrated micro-optical component

This paper presents a precision glass-molding process to fabricate planar-integrated micro-optical components (PIMOC) applied to a micro projection display system, optical interconnection system and optical storage system. The PIMOC was designed based on wave propagation theory, and fabricated using a glass molding process. Experimental results are discussed in this article. The experiment showed that the PIMOC fabricated in a vacuum environment meets the design value with precision glass-molding technology (PGMT) at a molding force of 2.75 kN, a molding temperature of 750 °C and a cooling rate of 49 °C/min.     

Giant magnetostriction materials

One of the significant technical developments in magnetism of the early 1970's was the discovery of a new class of rare earth intermetallic compounds, the RFe₂ Laves phases, which were found to exhibit room temperature magnetostrictive strains approaching 2 × 10⁻³, an order of magnitude larger than any previously known. Since that time both the fundamental and technical properties of these materials have been of intense interest, and they remain the subject of active research even today. The large strains available are useful in such applications as production of high amplitude, low frequency sound waves in water, certain types of strain gages, vibration compensation and compensation for temperature induced strains in large laser mirrors. Because the performance of these materials depends critically on such fundamental properties as the magnetic anisotropy, magnetization and grain orientation of the material, there has been a very strong interplay between fundamental studies and applications. In this article we briefly review the fundamental magnetic and magnetostrictive properties of the RFe₂ Laves phases, focusing especially on the complex behavior of the anisotropy and the success of crystal field theory in explaining it. We also present neutron measurements of magnetic excitation spectra and explain how they provide an understanding of the remarkable success of mean field theory for these systems.     

Conservative quantities and their algebra in the self-dual gravity

A general covariant conservation law of energy-momentum in complex general relativity is obtained by way of general displacement transformation in terms of Ashtekar's new variables. The energy is exactly the adm Hamiltonian on the constraint surface on condition that an appropriate time function is chosen. The energy-momentum is gauge covariant and commutes with all the constraints whence they are physical observables. Furthermore, the Poisson brackets of the momentum and the internalSU(2) charges form a 3-Poincaré algebra.     

A comparison of variational and discrete ordinate methods for solving radiative transfer problems

In this paper, we compare the variational and discrete ordinate methods applied to their simplest representative cases: the 2-step function variational method and the 2-stream approach. It is shown that both methods require minimal computational time. Numerical results of the source functions, intensities and fluxes for the problem of diffuse reflection by different plane-parallel isotropic atmospheres are compared between the two methods. Limitations of both approaches for different single scattering albedos and optical depths are discussed. It is also shown that the variational technique is a more efficient algorithm in handling multi-layer cloud conditions for radiative transfer problems.     

1.55-mum and infrared-band photoresponsivity of a Schottky barrier porous silicon photodetector

We have investigated the spectral responsivity of porous silicon Schottky barrier photodetectors in the wavelength range 0.4-1.7 mum . The photodetectors show strong photoresponsivity in both the visible and the infrared bands, especially at 1.55 mum . The photocurrent can reach 1.8 mA at a reverse bias of 6 V under illumination by a 1.55-mum , 10-mW laser diode. The corresponding quantum efficiency is 14.4%.     

Polypyrrole Nanospheres with Magnetic and Cell‐Targeting Capabilities

The preparation of polypyrrole/Fe₃O₄ nanospheres by a facile mini‐emulsion polymerization method is investigated using poly(ethylene glycol), poly(ethylene oxide), poly(vinyl alcohol), and hyaluronic acid as surfactants. Hyaluronic acid is deemed the most suitable surfactant since it results in well‐dispersed nanospheres of 80–100 nm, and offers the advantages of biocompatibility, cell adhesive property, and the availability of functional groups for attachment of other molecules. These polypyrrole/Fe₃O₄ nanospheres are magnetic and can be further functionalized with a cancer antibody, herceptin. Our results show that this combination of hyaluronic acid and herceptin results in high specific uptake of the nanospheres by cancer cells.