The hydrolysis of brilliant green and some derivatives. I. A kinetic and equilibrium study of the hydrolysis of brilliant green

The hydrolysis of Brilliant Green has been studied over the pH range 6–11. In neutral aqueous solution and in the absence of light, the system reaches equilibrium. In alkaline solution, complete conversion into the dye base occurs. Rate constants and activation parameters have been obtained for the hydrolysis and a reaction scheme is proposed.     

Effects of assertion training on acceptance of disability by physically disabled university students.

This pilot study focused on the effects of assertion training on 14 physically disabled undergraduates' acceptance of disability. A pretest–posttest control group design was utilized. Ss were randomly assigned to either a treatment group or a no-treatment control group. The hypotheses analyzed were that Ss given assertion training would show increases in Acceptance of Disability Scale scores, self-concept/esteem scores (Rathus Assertiveness Scale), and social interaction skills scores (Behavioral Observation Scale) when compared with individuals who did not experience assertion training. Significant results were obtained for all hypotheses indicating that the groups differed in acceptance of disability, self-concept, and social interaction. The study suggests that assertion training may be effective for increasing acceptance of disability in physically disabled students. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autonomic functioning in process and reactive schizophrenia.

Compared the autonomic functioning of male process schizophrenics, reactive schizophrenics, and normal ss (n = 30) under rest and arousal conditions. Ss were exposed to 6 arousal conditions: (a) white noise, (b) electric shock, (c) paired associate learning, (d) word activity test, (e) finger dexterity task, and (f) pursuit rotor task. Rest periods preceded each arousal condition. Heart rate, skin resistance, respiration rate, diastolic and systolic blood pressures were recorded under all 6 conditions. Results show that under stress the levels of physiological functioning for normal ss and reactive schizophrenics were similar on skin resistance and blood pressure, with process schizophrenics showing a higher level of arousal on skin resistance and a lower level on blood pressure. Reactive schizophrenics had the fastest heart rate, with process schizophrenics next, and normals the lowest. Respiration did not reliably differentiate among the groups. Reactive schizophrenics and normals generally showed greater increments to the arousal conditions (compared with prestress base lines) than the process schizophrenics in all measures except heart rate and skin resistance. In those 2 measures, reactive and process schizophrenics were similar in their reactions to the stress conditons, and both groups showed less reactivity in general than normals. (french summary) (31 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The status of Black males in America: A data base search.

Discusses database searching strategies for topics in psychology, using, as an example, the present authors' (1988) bibliography of research on Black males in the US, compiled from the PsycINFO database. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infants' intermodal knowledge about gender.

The aim of this study was to seek evidence of intermodal knowledge about gender in infants that would provide direct evidence of the existence of gender categories during the 1st yr of life. In Exp 1, 20 9- and 24 12-mo-olds were presented with pairs of male and female pictures with a female or male voice presented simultaneously. Ss spent significantly more time looking at the pictures matching the voices than at the same pictures paired with mismatching voices, but only in the case of female stimuli. Comparison to chance level performance suggested that the matching effect was more consistent in older Ss. In Exp 2, 20 9-mo-olds were tested with a set of highly stereotypical faces and distinctive male and female voices. Ss showed a preference for the faces matching the voices, but this effect was again restricted to female stimuli. Results of both studies suggest that intermodal knowledge about gender develops during the 2nd half of the 1st yr. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of the strength of adhesion between a thermoresponsive polymer coating and nitinol wire

As polymer coatings become more widely used in the biomedical device industry, both to improve biocompatibility and as coatings for localised drug delivery, quantitative methods to measure the adhesive strength between coatings and substrates become a very important consideration. The aim of this study was to take a method for estimating the interfacial fracture toughness of a film to a flat substrate and apply it to Nitinol wires used in the production of medical devices. An investigation into the affect of surface roughness on the fracture toughness was also conducted. For the present study, a thermoresponsive based Poly (N-isopropylacrylamide) polymer was coated onto nitinol wire substrates and the adhesion strength between the polymer and wire was measured using a nanoindentation technique. Different surface treated nitinol wires, with different surface topography and roughness were used, and the affect of these surface properties on adhesion strength was investigated. Results showed that it was possible to apply the delamination technique to wire samples and obtain fracture toughness values. Results also showed that the surface roughness is an important parameter that can affect the adhesion between a coating and the substrate. It was found that, as the average surface roughness increased so also did the adhesive strength between the coating and wire sample.     

Doxorubicin eluting beads—2: methods for evaluating drug elution and in-vitro:in-vivo correlation

DC Bead™ is a sulfonate-modified, PVA-based microspherical embolisation agent approved for the treatment of hypervascular tumours and arterio-venous malformations. The beads have previously been shown to actively sequester oppositely charged drugs, such as doxorubicin hydrochloride (dox) by an ion-exchange mechanism. In order to characterise the release kinetics and predict the in vivo behaviour of drug eluting beads (DEB), two elution methods were utilised. The first, an application of the USP dissolution method Type II - Apparatus, enables study of the complete elution of loaded DC Bead in less than 4 h, allowing relatively rapid comparison to be made between different products and formulations. Release data obtained using this method were fitted to first order kinetics (R ² > 0.998) and the elution constants shown to increase with the total surface area of the beads exposed to the elution medium. Diffusion coefficients were calculated adopting the Fickian diffusion model, which predicted slow elution rates under physiological conditions. The second method involved the use of a T-Apparatus where the drug experiences an element of diffusion through a static environment. This method was developed to resemble the in vivo situation in embolisation procedures more closely. Slow release of dox from DC Bead with half-lives over 1,500 h were predicted for all size ranges using a slow release model. A strong linear relationship was found between the release data from T-Apparatus and pharmacokinetic data obtained from patients treated with DC Bead loaded with dox in transarterial chemoembolisation (TACE) procedures. These data indicated a Level A in vitro–in vivo correlation (IVIVC) for the first 24 h post embolisation. Both systems developed were automated and good reproducibility was obtained for all samples, demonstrating the usefulness of these elution techniques for product development and comparative testing.     

The association of dental caries with blood lead in children when adjusted for IQ and neurobehavioral performance

Associations between childhood lead exposures and dental caries in children have been reported for over 30 years, with widely varying findings and conclusions, and using measures of lead exposure which ranged from food sources and water to tooth, hair or blood lead concentrations. OBJECTIVES: This study examined the relationship of lead exposure and dental caries in a population of normatively healthy children. METHODS: This cross-sectional study used a population of 507 children aged 8-12 who were participating in a clinical trial of dental materials to examine the relationship between lead and caries. Blood lead concentrations and dental caries were examined for association in both primary and permanent teeth. Because it is possible that neurobehavioral status could be associated with both lead exposure and dental caries prevalence, we also examined neurobehavioral status of the subjects. RESULTS: A gender-specific association (males only) between lead exposure and dental caries was found in primary teeth only. Neurobehavioral measures and IQ were not associated with caries status in this population. CONCLUSIONS: This study did not support neurobehavioral status as mediating any association between lead exposure and caries in a normatively healthy population. A gender-specific association between lead and caries not previously reported was found in primary teeth, and no biological explanation for this has been suggested. We conclude that this study provides only weak evidence, if any, for an association of low-level lead exposure with dental caries.     

An evaluation of the effects of antimony and tin stabilizer on the fusion characteristics of PVC dryblends

Although the classification of lubricants can be misleading, the classification of their actions is not only possible but very useful. By considering the basic actions which affect PVC dryblend fusion, a better understading of the characteristics and advantages of additives can be realized. The antimony and tin stabilizers used in this study have been characterized by the affects on PVC dryblend fusion. Production extrusion results confirm the laboratory classifications.