Purpose: Morphological study comparing castor oil polyurethane and autogenous bone graft to repair bone defect in zygomatic bone of rabbits. Methods: Twenty-four adult, male New Zealand rabbits were randomly distributed between two groups of twelve. Bone defects of 5mm in diameter were cut through the zygomatic bone and filled with polyurethane discs in the experimental group or autogenous bone...

Polyurethane/zeolite 13X nanocomposite films were fabricated using solution casting method. The synthesized nanocomposite films were structurally characterized using SEM, TGA and tensile analysis. SEM images showed appropriate distribution of nanocrystalline zeolite particles within polyurethane matrix. Better thermal stability of nanocomposite films in comparison to neat polyurethane was shown...

AIMS To better understand the role of PueA and PueB from Pseudomonas chlororaphis in polyurethane degradation, the present study was conducted to create insertional mutants in their respective genes. METHODS AND RESULTS Growth kinetic studies showed that the pueA knockout mutant had a greater effect than the pueB knockout mutant. The pueA mutant had an 80% decrease in cell density from that o...

This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m² and 16.39 kW/m² for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both ...

Mg(OH)2 nanoparticles were synthesized by a rapid microwave reaction. The effect of sodium dodecyl sulfonate (SDS as anionic surfactant) and cetyl tri-methyl ammonium bromide (CTAB as cationic surfactant) on the morphology of magnesium hydroxide nanostructures was investigated. Multi wall carbon nano tubes was organo-modified for better dispersion in cellulose acetate matrix. The influence of M...

A composite foam of polyurethane/chitosan with chitosan content of 20 wt% was successfully prepared as an adsorbent for the removal of malachite green from aqueous solution, the structures and properties were characterized by scanning electron microscope and Fourier transform infrared spectroscopy. The results showed open cell content of polyurethane/chitosan was more than 95% and open cell str...

BACKGROUND As surgeons working in a developing country, we decided to review our experience with polyurethane stents instead of the more expensive ones on common urological procedures and analyzing our experience with respect to their usefulness versus their problems and outcome. METHODS This stusy was carried out at Armed Forces Institute of Urology, Rawalpindi and Combined Military Hospital...

Calcification complicates the use of the polymer polyurethane in cardiovascular implants. To date only costly experimental circulatory animal models have been useful for investigating this disease process. In this paper we report that polyurethane calcification in rat subdermal implants is enhanced by overdosing with a vitamin-D analog. The calcification-prone state, known as calciphylaxis, was...

Periodic density functional theory (DFT) calculations have recently emerged as a popular tool for assigning solid-state nuclear magnetic resonance (NMR) spectra. However, in order for the calculations to yield accurate results, accurate structural models are also required. In many cases the structural model (often derived from crystallographic diffraction) must be optimised (i.e., to an energy ...

Topical hemostatic agents can be used to treat problematic bleedings in patients who undergo surgery. Widely used are the collagen- and gelatin-based hemostats. This study aimed to develop a fully synthetic, biodegradable hemostatic agent to avoid exposure to animal antigens. In this in vitro study the suitability of different newly developed polyurethane-based foams as a hemostatic agent has b...