Pulsed laser deposition of relaxor ferroelectric films

Heterostructures of perovskite relaxor ferroelectric (RFE) thin films onto La0.5Sr0.5CoO3, bottom electrode layers were grown by pulsed laser deposition on MgO(100) crystal substrates. The films were highly oriented, with (h00) planes parallel to the substrate surface, and demonstrated good dielectric and ferroelectric quality at room temperature. The studies of the dielectric properties of the films over the frequency range of 20 Hz .... 100 kHz and over the temperature range of 0...350°C revealed relaxor type behavior in the films. A diffuse ferroelectric phase transition and a shift of the maximum dielectric permittivity towards higher temperatures with increasing frequency were observed. Interferometric measurements of piezoelectric response of the heterostructures at room temperature yielded piezoelectric coefficients in the range of 25 ... 60 pm/V at 1 kHz, increasing up to 200 ... 250 pm/V at 60 Hz. The obtained results look promising for micromechanical applications of RFE thin films

Influence of layer interface parameters on dielectric characteristics of BSTO ferroelectric film planar capacitors

Ferroelectric BaxSr1-xTiO3 (BSTO) films were prepared on sapphire (r-cut) and MgO substrates using two preparation processes- RF sputtering aid the sol-gel rnethod. The structure of the films and interfaces were investigated by middle energy ion back scattering combined with ion channelling. Planar capacitors patterned on the film allowed the temperature dependence of capacitance and voltage-capacitance characteristics (VCC) to be measured at a frequency of 1 MHz. The influence of some interface parameters (e.g. the presence of intermediate layers, structural ordering of the BSTO surface layer, the type of film electrode) on dielectric characteristics, VCC hysteresis and tunability of the planar capacitors are discussed

Frequency of anxiety after stroke: a systematic review and meta-analysis of observational studies.

BACKGROUND AND PURPOSE: Negative psychological outcomes occur frequently after stroke; however, there is uncertainty regarding the occurrence of anxiety disorders and anxiety symptoms after stroke. A systematic review of observational studies was conducted that assessed the frequency of anxiety in stroke patients using a diagnostic or screening tool. SUMMARY OF REVIEW: Databases were searched up to March 2011. A random effects model was used to summarize the pooled estimate. Statistical heterogeneity was assessed using the I(2) statistic. Forty-four published studies comprising 5760 stroke patients were included. The overall pooled estimate of anxiety disorders assessed by clinical interview was 18% (95%confidence interval 8-29%, I(2)  = 97%) and was 25% (95% confidence interval 21-28%, I(2)  = 90%) for anxiety assessed by rating scale. The Hospital Anxiety and Depression Scale-Anxiety subscale 'probable' and 'possible' cutoff scores were the most widely used assessment criteria. The combined rate of anxiety by time after stroke was: 20% (95% confidence interval 13-27%, I(2)  = 96%) within one-month of stroke; 23% (95% confidence interval 19-27%, I(2)  = 84%) one to five-months after stroke; and 24% (95% confidence interval 19-29%, I(2)  = 89%) six-months or more after stroke. CONCLUSION: Anxiety after stroke occurs frequently although methodological limitations in the primary studies may limit generalizability. Given the association between prevalence rates and the Hospital Anxiety and Depression Scale-Anxiety cutoff used in studies, reported rates could in fact underrepresent the extent of the problem. Additionally, risk factors for anxiety, its impact on patient outcomes, and effects in tangent with depression remain unclear

A novel allelic variant of the human TSG-6 gene encoding an amino acid difference in the CUB module. Chromosomal localization, frequency analysis, modeling, and expression.

Tumor necrosis factor-stimulated gene-6 (TSG-6) encodes a 35-kDa protein, which is comprised of contiguous Link and CUB modules. TSG-6 protein has been detected in the articular joints of osteoarthritis (OA) patients, with little or no constitutive expression in normal adult tissues. It interacts with components of cartilage matrix (e.g. hyaluronan and aggrecan) and thus may be involved in extracellular remodeling during joint disease. In addition, TSG-6 has been found to have anti-inflammatory properties in models of acute and chronic inflammation. Here we have mapped the human TSG-6 gene to 2q23.3, a region of chromosome 2 linked with OA. A single nucleotide polymorphism was identified that involves a non-synonymous G --> A transition at nucleotide 431 of the TSG-6 coding sequence, resulting in an Arg to Gln alteration in the CUB module (at residue 144 in the preprotein). Molecular modeling of the CUB domain indicated that this amino acid change might lead to functional differences. Typing of 400 OA cases and 400 controls revealed that the A(431) variant identified here is the major TSG-6 allele in Caucasians (with over 75% being A(431) homozygotes) but that this polymorphism is not a marker for OA susceptibility in the patients we have studied. Expression of the Arg(144) and Gln(144) allotypes in Drosophila Schneider 2 cells, and functional characterization, showed that there were no significant differences in the ability of these full-length proteins to bind hyaluronan or form a stable complex with inter-alpha-inhibitor