Thermal Diffusivity in Supercritical Fluids Measured by Thermal Lensing

Thermal diffusivities of supercritical CO₂ and C₂H₆ were determined over a wide density range with a photothermal technique. The thermal lens, formed by the degradation of the absorbed light energy as heat by the sample, allows the employment of a nonequilibrium method in the critical region. Controlling the refractive-index gradient, i.e., a density gradient, perturbations can be maintained at levels where convection is negligible. An easy-to-operate setup allowed us to measure thermal diffusivities in the density ranges 5 to 20 mol·dm^–3 for CO₂ at 308 and 313 K and 2 to 12 mol·dm^–3 for C₂H₆ at 308 K with a standard precision of 15%.     

The molecular biology of bladder carcinoma

OBJECTIVE: The clinical course of transitional cell carcinoma of the bladder can be difficult to predict due to its potential to invade the muscle layer and/or develop to a high grade lesion. Bladder carcinoma can arise from genetic changes that may activate the oncogenes (-c-erbB2, c-erbB1, c-myc, ras, etc.) and/or inactivate the suppressor genes (p53, Rb). The aim of the present study is to continue a study protocol on the molecular biology of bladder tumors. METHODS/RESULTS: From January, 1993 to January, 1995, 85 patients were studied. These patients were divided into two groups: the first group comprised 14 controls of urothelial tissue and the second comprised 65 cases of transitional cell carcinoma of the bladder. p53 expression was determined by an immunohistochemical method (NCL-p53-DO7 monoclonal antibody). Quantification of the p8 oncoprotein in cytosol and EGFR (epidermal growth factor receptor) in membrane was performed by ELISA (Oncogene Science) and RIA (Vienna Lab), respectively. A statistically significant relationship between the expression of p53 and EGFR with tumor stage and grade was found. Quantification of p185 and EGFR showed higher values in the tumor tissue than in the control samples, but a worse survival could not be determined. CONCLUSIONS: The present study shows that p53 expression can be considered to be a prognostic factor. It provides useful information on the aggressive behaviour of the tumor and has a direct relation with the survival rates.     

Application of Romero García method to the degradation process of DGEBA/ETDA filled with ultra fine metallic copper

Summary The thermal properties of an epoxy resin (diglycidyl ether Bisphenol A, DGEBA) cured with a primary amine (ethylenediamine, ETDA) and filled with 10, 20 and 30 wt. % of ultra fine copper particles were analyzed. The thermal results were evaluated by means of the Romero-Garcia method, which allowed to obtain the resin degradation kinetic parameters, as well as the possible decomposition mechanism. From the obtained results is possible to infer that higger copper content strongly affects the degradation process of the epoxy resin, which causes a drop off on the composites thermal stability. This behavior could be attributed to water presence, being this effect less pronounced for the resin with 10 wt. % copper and unfilled resin. Regarding to decomposition mechanism, three way transport showed the best correlation for all samples.     

A Study of Ozone Generation by Negative Corona Discharge Through Different Plasma Chemistry Models

The Steady radial distribution of chemical species in a wire‐to‐cylinder ozone generator filled with pure oxygen has been computed by applying four different plasma chemistry models of increasing complexity. The most complete model considers ten species (e, O₂ ⁺, O₂ ^?, O₃ ^?, O^?, O₂, O₂(¹Δ_g), O₂(¹∑_g ⁺), O and O₃) and 79 reactions, including ionization by electron impact, electron attachment and detachment, electron-ion recombination, charge transfer, etc. The chemical model is coupled with the electrical model through Poisson's equation. The spatially averaged ozone density has been computed as a function of the current intensity and compared with the experimental values obtained by UV spectroscopy.     

A comparative study of the durability and behaviour of fat lime and feebly-hydraulic lime mortars

Lime mortars are often used for repairs to historic buildings. This paper investigates two forms of lime binder: fat and feebly-hydraulic, in order to predict their long-term behaviours and hence ascertain which of the two possesses greater durability, so that they may be used more efficiently in restoration. Mortars were tested for properties governing moisture movement and also subject to durability cycles. The resistance to damage under freezing conditions was evaluated with the saturation coefficient. Thermal cycles had no effect on the mortars and gave no indication of the relative durabilities of the binders. Salt crystallization cycles, though effective in distinguishing the more durable of the two, were too aggressive to gauge a clear profile of salt weathering and succeeded in rapidly decomposing the samples. Tests on the properties governing moisture movement produced good indications of the degree to which the mortars permit flow through their fabrics. According to the results obtained, fat lime mortars are more durable than those made with feebly-hydraulic lime. The results also suggest that the feebly-hydraulic lime mortars are at a higher risk of decomposition by granular disintegration whereas fat lime mortars are better suited to damp, slightly exposed conditions. These results disagree with the general opinion that hydraulic limes are more durable than fat limes due to the additional strength and water insolubility arising from their hydraulicity.     

Assessment of Bonelike® graft with a resorbable matrix using an animal model

Synthetic bone grafts have been developed to provide an alternative to autografts and allografts. Bonelike® is a patented synthetic osteoconductive bone graft that mimics the mineral composition of natural bone. In the present preliminary animal studies a user-friendly version of synthetic bone graft Bonelike® have been developed by using a resorbable matrix, Floseal®, as a vehicle and raloxifene hydrochloride as a therapeutic molecule, that is known to decrease osteoclast activity and therefore enhanced bone formation. From histological and scanning electron microscopy evaluations, the use of Bonelike® associated with Floseal® and raloxifene hydrochloride showed that new bone was rapidly apposed on implanted granules and also that the presence of the matrix and therapeutic molecule does not alter the proven highly osteoconductivity properties of Bonelike®. Therefore, this association may be one step-forward for the clinical applications of Bonelike® scaffolds since it is much more easy-to-handle when compared to granular materials.     

Syllables as processing units in handwriting production.

This research focused on the syllable as a processing unit in handwriting. Participants wrote, in uppercase letters, words that had been visually presented. The interletter intervals provide information on the timing of motor production. In Experiment 1, French participants wrote words that shared the initial letters but had different syllable boundaries. In Experiment 2, French- and Spanish-speaking participants wrote cognates and pseudowords with a letter sequence that was always intrasyllabic in French and intersyllabic in Spanish. In Experiment 3, French-Spanish bilinguals wrote the cognates and pseudowords with the same type of sequences. In the 3 experiments, the critical interletter intervals were longer between syllables than within syllables, indicating that word syllable structure constrains motor production both in French and Spanish. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Report on the therapeutic use of rimantadine and amantadine]

A discussion is carried out about the experiences with the application of rimantadine and amantadine to patients with influenza. The basic general results consisted in the fact that 2 of the 74 patients treated had a high cure percent (> 68.0%) within the first 72 hours after using the drug. No new diseased were found among the 40 contacts to whom chemoprophylaxis was applied. There were only 3.9% adverse reactions among the total number of people treated with amantadine.