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Not only is depression associated with increased inflammation but inflammation is a risk factor for the genesis of depression. Many of the environmental risk factors for depression are transduced through inflammatory signaling. Anti-inflammatory agents show promise for the management of depression in preclinical, epidemiological, and early clinical studies. This opens the door to the potential for anti-inflammatory agents to treat and prevent depression. There are no evidence-based pharmacotherapies for depression prevention.
ASPREE-D, aspirin in the prevention of depression in the elderly, is a sub study of ASPREE, which explores the potential of aspirin to prevent a range of inflammation related disorders in the elderly. With a sample size of 19,114, and a duration of 5 years, this placebo controlled study will be one of the largest randomized controlled trials in psychiatry and will provide definitive evidence on the ability of aspirin to prevent depression.
This paper presents the rationale for the study and presents a summary of the study design.
ASPREE-D may not only define novel therapy but will provide mechanistic proof of concept of the role of inflammation in depression.
Supplemented protein or specific amino acids (AA) are proposed to help animals combat infection and inflammation. The current study investigates whole-body and splanchnic tissue metabolism in response to a lipopolysaccharide (LPS) challenge with or without a supplement of six AA (cysteine, glutamine, methionine, proline, serine and threonine). Eight sheep were surgically prepared with vascular catheters across the gut and liver. On two occasions, four sheep were infused through the jugular vein for 20 h with either saline or LPS from Escherichia coli (2 ng/kg body weight per min) in a random order, plus saline infused into the mesenteric vein; the other four sheep were treated with saline or LPS plus saline or six AA infused via the jugular vein into the mesenteric vein. Whole-body AA irreversible loss rate (ILR) and tissue protein metabolism were monitored by infusion of [ring-2H2]phenylalanine. LPS increased (P<0·001) ILR (+17 %), total plasma protein synthesis (+14 %) and lymphocyte protein synthesis (+386 %) but decreased albumin synthesis (−53 %, P=0·001), with no effect of AA infusion. Absorption of dietary AA was not reduced by LPS, except for glutamine. LPS increased the hepatic removal of leucine, lysine, glutamine and proline. Absolute hepatic extraction of supplemented AA increased, but, except for glutamine, this was less than the amount infused. This increased net appearance across the splanchnic bed restored arterial concentrations of five AA to, or above, values for the saline-infused period. Infusion of key AA does not appear to alter the acute period of endotoxaemic response, but it may have benefits for the chronic or recovery phases.
The presence or absence of dwarf galaxies with Mr' > -14 in low-density volumes correlates with dark matter halos and how they affect galaxy formation. We are conducting a redshifted Hα imaging survey for dwarf galaxies with Mr' > -13 in the heart of the well-defined voids FN2 and FN8 using the KPNO 4m Mayall telescope and Mosaic Imager. These data have furnished over 600 strong candidates in a four square degree area. Follow-up spectra finding none of these candidates to be within the void volumes will constrain the dwarf population there to be 2 to 8% of the cosmic mean. Conversely, finding even one Hα dwarf in the void heart will challenge several otherwise successful theories of large-scale structure formation.
The increased occurrence of obstetric complications (OCs) in patients with schizophrenia suggests that alterations in neurodevelopment may be of importance to the aetiology of the illness. Abnormal cortical folding may reflect subtle deviation from normal neurodevelopment during the foetal or neonatal period. In the present study, we hypothesized that OCs would be related to cortical folding abnormalities in schizophrenia patients corresponding to areas where patients with schizophrenia display altered cortical folding when compared with healthy controls.
In total, 54 schizophrenia patients and 54 healthy control subjects underwent clinical examination and magnetic resonance image scanning on a 1.5 T scanner. Information on OCs was collected from original birth records. An automated algorithm was used to calculate a three-dimensional local gyrification index (lGI) at numerous points across the cortical mantle.
In both schizophrenia patients and healthy controls, an increasing number of OCs was significantly related to lower lGI in the left pars triangularis (p<0.0005) in Broca's area. For five other anatomical cortical parcellations in the left hemisphere, a similar trend was demonstrated. No significant relationships between OCs and lGI were found in the right hemisphere and there were no significant case–control differences in lGI.
The reduced cortical folding in the left pars triangularis, associated with OCs in both patients and control subjects suggests that the cortical effect of OCs is caused by factors shared by schizophrenia patients and healthy controls rather than factors related to schizophrenia alone.
We have applied angle-resolved laser scatterometry to characterize the morphology of metals deposited under various conditions. Scatterometry is a rapid, noncontact and nondestructive diagnostic which yields surface statistics including rms roughness and power spectral density of the microstructure.
Ferroelectric oxide films have been studied for their potential application as integrated optical materials and nonvolatile memories. Electro-optic properties of potassium niobate (KNbO3) thin films have been measured and the results correlated to the microstructures observed. The growth parameters necessary to obtain single phase perovskite lead zirconate titanate (PZT) thin films are discussed. Hysteresis and fatigue measurements of the PZT films were performed to determine their characteristics for potential memory devices.
Silicon dioxide (SiO2) films were fabricated by microwave ECR plasma processing. Two groups of films were fabricated; group A with the substrates placed in a position directly facing the plasma so that the substrates as well as the on-growing films were subjected to bombardment of energetic particles produced in the plasma, and group B with the substrates placed in a processing chamber physically separated from the plasma chamber in order to prevent or suppress the damaging effects resulting from these energetic particle bombardment. The systems used for fabricating these two different groups of samples are described. The films were deposited at various deposition temperatures. On the basis of the deposition rate as a function of deposition temperature the film growth for group A samples is due mainly to mass-limited reaction, and that for group B samples is due to surface rate limited reaction. The stoichiometric level for group A does not change with deposition temperature though the films density increases with increasing deposition temperature. However, group B samples exhibit an off-stoichiometric property but they become highly stoichiometric as the deposition temperature is increased beyond 200 °C
A comparative study of CH4 :H2 , and CH4 :H2 :Ar rf-plasma and microwave electron cyclotron resonance (ECR) plasma etching of GaAs and InP is presented. The study is in two parts;
(i) Kinetic studies of GaAs and InP etch rates as a function of the constituent gas flow rates, applied rf and microwave powers, substrate temperature and position. The results indicate that CH4 :H2 :Ar ECR etching of GaAs is 10× more efficient in the utilisation of the CH4 precursor gas than rf-plasmas. However, the absolute etch rates are lower (70 nm min−1 for rf and 25 nm min−1 for rf biassed ECR-plasmas).The effect of etching conditions on InP morphology is also examined.
(ii) The study of electrical “damage” in GaAs/AlGaAs high electron mobility transistor (HEMT) Hall bar structures, was investigated by ECR-plasma etching off the top GaAs capping layer. Results indicate that ECR-plasma etching with an rf-bias between 0V and −30V does not significantly effect the electrical characteristics of such devices at 300K, with some degredation at 1.2 K.
Aluminium nitride film has been synthesized at substrate temperatures lower than 100 °C by using ion beam enhanced reactive magnetron sputtering. The growth rate was much higher than that obtained by usual physical vapor deposition at low substrate temperatures. The stoichiometry of the film was controlled by varying the resultant current of the ion beam used and identified by X-ray diffraction analysis. The optical properties of the film were also studied.
We report optical studies of predominantly c-axis oriented high-Tc superconducting films before and after ion milling. A significant increase in midinfrared reflectivity resulted from ion milling of a few thousand Å Features associated with α-axis texture vanished after ion milling, resulting in pure c-axis films. This suggests that α-axis grains reside mostly near the surface in post-annealed high-Tc superconducting films. Therefore, even after annealing (for the purpose of raising Tc), highly oriented c-axis films can be retained by ion milling. This may be important for device applications where optically smooth surfaces and interfaces are to be routinely prepared.
Low temperature heteroepitaxial growth of Si1−xGex films with mole fractions “x” ranging from 0.07 to 0.72 on Si(100) has been achieved by Remote Plasma-enhanced Chemical Vapor Deposition (RPCVD) at substrate temperatures of 305°C and 450°C. Reflection High Energy Electron Diffraction (RHEED), Transmission Electron Microscopy (TEM), and Secondary Ion Mass Spectroscopy (SIMS) were employed to characterize the crystallinity, composition and interfacial sharpness. The Si1−xGex films with thickness below the critical layer thickness were confirmed to have excellent crystallinity with defect density below the sensitivity of TEM analysis (105 cm−2). The Ge profile, from SIMS analysis, in a Si/Si0.8Ge0.2/Si/Si0.82Ge0.18 multilayer structure was found to have a transition width of 30Å/decade, which is the resolution limit of SIMS analysis. There is no Ge segregation observed at the Si/Si1−xGex interface. A superlattice structure with 24 pairs of Si(60Å)/Si0.8Ge0.2 (60Å) layers has been successfully grown by RPCVD at 450°C. From cross-sectional TEM analysis, very low defect densities and abrupt Ge transitions were confirmed.
In this study we show that upon exposure to electron cyclotron resonance hydrogen plasmas, both thermally grown and sputter deposited oxides are degraded, resulting in large shifts of flat band voltage, and increases in fixed charge and interface state density.
This paper addresses the issue of chlorine adsorption on GaAs(100) with respect to the mechanisms of thermal and ion-enhanced etching. The use of halogenated precursors eg. dichloroethane is also discussed in regard to chemically assisted ion beam etching (CAIBE).
Direct ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.
A high-current, low-energy multi-ion beam deposition system has been developed for the fabrication of tailored new materials. This system consists of two ion sources, a dual-sector type mass analyzer and a deceleration system. Several ion species can be extracted successively from the two ion sources by switching the mass analyzer selection. Artificially structured materials, especially having a layered structure, can be grown by the fine control of the growth process of each layer. Ar* ion deceleration characteristics of this ion beam deposition system and preliminary results about the epitaxial growth of Ca film on Si(100) are shown.
The effect of low energy (0.5 to 5 keV) Ar+ beams on the surface structure and composition of monocrystalline ternary In0.53Ga0.47As and quaternary In0.70Ga0.30As0.64P0.36 films epitaxially grown by MO-VPE on InP (100) substrate has been investigated. Quantitative Auger electron spectroscopy has been used with the elemental standard method taking into account the electron diffraction effects. For both semiconductors, the outermost surface layer has been found to be Ga and In enriched. In the subsurface region, the Ga enrichment is even larger, at the expense of As and In. In the quaternary film, P is depleted in the surface as well in the subsurface region. Angular Resolved Auger Electron Spectroscopy is applied to the structural study of the sputter-etched surface. The nature and spatial extension of the ion-induced surface damage have been investigated at different energies, and doses of the primary ion beam. Is has been found that the resistance to the amorphization is strongly enhanced in InGaAs with respect to GaAs.
High-energy hydrogen ion (proton) implantation is used in Si for creating defects, while low-energy H is known for passivation of a variety of defects and impurities. We have carried out a study of low-energy (<0.4 keV) H passivation of defects produced by 100 keV H implantation. Both Schottky barrier transport and deep level transient spectroscopy measurements give evidence for self-passivation of defects produced by H.
Silicon bulk micromachined piezoresistive pressure sensors are sensitive to stresses caused by the application of inorganic thin films typically used for passivation purposes, and the change in stress that is caused by temperature changes in the operating environment of the sensor. Stress behavior over temperature is characterized for both thermal oxides grown on silicon at thicknesses from 0.18 μm to 0.36 μm, and PECVD silicon nitride films at thicknesses from 0.40 μm to 0.80 μn. Electrical parametric behavior is characterized for typical piezoresistive pressure sensors with these thin films deposited and patterned in several proposed passivation schemes. A finite element analysis is performed to predict how device parameters vary as a function of thin film patterning and properties. Correlations are drawn between model predictions, independent thin film behavior, and device performance.
Double layer (DL) Ba0.7Sr0.3TiO3 (BST) capacitors with Pt electrodes have been fabricated with similar growth conditions on different substrates. The substrates used in the present study were r-plane sapphire, polycrystalline alumina Al2O3 (99.6% and 96%), and glazed polycrystalline alumina. BST films were grown by metal-organic decomposition (MOD) method. By varying the annealing conditions which affects the formation of the crystalline structure, significant changes in the dielectric properties of the BST films have been observed. BST films were characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Powder X-ray Diffractometer (PXRD). These observations showed that BST films grown at lower temperatures on alumina substrates exhibited the smallest grain size. BST films of the same thickness prepared under the same thermal processing conditions showed higher capacitance when grown on all types of alumina-based substrates compared to those deposited on control SiO2/Si. The higher capacitance on alumina was always associated with larger dissipation factor, and lower or similar leakage current density. The final tuning, of the dielectric properties of BST DL capacitors on non-silicon substrates, was correlated to the initial film formation temperature and post-annealing conditions of the BST films. The leakage current density, of DL BST capacitors fabricated on glazed alumina, becomes smallest when the BST processing temperature was lowered by 100 °C compared to the control SiO2/Si. The typical achieved leakage current density for 1500×1500 μm2 DL capacitors on glazed alumina was 3.8×10-9 A/cm2 at 250 kV/cm (36.5 fF/μm2), about 3 times lower than on SiO2/Si substrates (1.1×10-8 A/cm2 at 250 kV/cm, 31 fF/μm2).