Stability of vocabulary performance by schizophrenics.

After 13 additional years of institutionalization, 31 schizophrenic men and 36 schizophrenic women were retested with the Wechsler Bellevue vocabulary test, Form I. No Significant decline was found in vocabulary performance. The findings did not support the hypothesis that prolonged institutionalization induces intellectual deterioration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evaluation of linear model analysis techniques for processing images of microcirculation activity

Clinicians in several countries have expressed concerns about possible adverse effects of shortening obstetric length of stay. A population-based survey of 1366 mothers who gave birth in Victoria, Australia, in 1993 was used to investigate social and obstetric characteristics of mothers discharged home 'early', and to assess whether shorter stays were associated with adverse health outcomes, or a lesser degree of satisfaction, or both. Women's views and experiences of length of hospital stay were gathered via a statewide postal survey of women who gave birth in a 2-week period; 62.5% (n = 1336) responded. Assessment of the relationship between length of stay (1-2 days vs. > or = 5 days, and 3-4 days vs. > or = 5 days) and four main outcome measures (infant feeding at 6 weeks, period prevalence of feeding problems, maternal confidence and depression) showed no association between these variables and length of stay after adjusting for other obstetric and social factors in separate regression analyses. For stays of 3-4 days, the adjusted odds ratio (OR) for formula feeding at 6 weeks was 1.35 [95% confidence interval (CI) 0.9-1.9]; for feeding problems OR = 0.87 [0.7-1.2]; for lacking confidence OR = 0.81 [0.6-1.2]; and for depression OR = 0.96 [0.7-1.4]. Large randomised trials of early obstetric discharge are required to resolve continuing uncertainties about the safety, and possible benefits of shorter hospital stays.     

Effect of frequency on ambient temperature fatigue crack growth in a silicon carbide reinforced silicon nitride composite

A detailed study on a silicon nitride reinforced with silicon carbide whiskers has been undertaken on room temperature fatigue during static and dynamic loading at constant ΔK. It is shown that sub-critical crack growth rates are lower when the material experiences sustained far field loading than during cyclic far field loading. The increased crack growth rate during cyclic loading is attributed to a wedging effect within the crack wake causing an increase in the tensile stress and resultant increased micro-cracking ahead of the crack tip. This additional micro-structural damage leads to enhanced sub-critical crack growth rates during cyclic loading. The asperities that are responsible for the wedging effect are attributed to the isolation of small portions of material due to branching of small cracks and by degradation of the bridging SiC whiskers and Si₃N₄ grains within the crack wake.     

Protein deposition on contact lenses: The past, the present, and the future

Proteins are a key component in body fluids and adhere to most biomaterials within seconds of their exposure. The tear film consists of more than 400 different proteins, ranging in size from 10 to 2360 kDa, with a net charge of pH 1-11. Protein deposition rates on poly-2-hydroxyethyl methacrylate (pHEMA) and silicone hydrogel soft contact lenses have been determined using a number of ex vivo and in vitro experiments. Ionic, high water pHEMA-based lenses attract the highest amount of tear film protein (1300 μg/lens), due to an electrostatic attraction between the material and positively charged lysozyme. All other types of pHEMA-based lenses deposit typically less than 100 μg/lens. Silicone hydrogel lenses attract less protein than pHEMA-based materials, with <10 μg/lens for non-ionic and up to 34 μg/lens for ionic materials. Despite the low protein rates on silicone hydrogel lenses, the percentage of denatured protein is typically higher than that seen on pHEMA-based lenses. Newer approaches incorporating phosphorylcholine, polyethers or hyaluronic acid into potential contact lens materials result in reduced protein deposition rates compared to current lens materials.