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Designing a scaffold with appropriate level of porosity, mechanical strength and bioactivity is essential for bone tissue engineering. In this study, a hydroxyapatite (HAp)/diopside nanocomposite scaffold was fabricated through foam replication method. The optimal sample was specified using central composition design (CCD) statistical method regarding HAp to diopside weight ratio, sintering temperature and lubricant content. A HAp/20 wt.% diopside sample containing 0.64% of lubricant sintered at 1200°C was chosen as the optimal sample and compared to a pure HAp sample. A porosity percentage of 84.48% and a compressive strength of 0.63 MPa was recorded for the optimal sample. The bioactivity evaluation in simulated body fluid (SBF) indicated that the HAp/20 wt.% diopside scaffold presented more formation of Si-OH layer and apatite nucleating site in comparison with the pure HAp scaffold. Based on the results, the HAp/20 wt.% diopside nanocomposite scaffold can be an appropriate candidate for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

The surface treatment is important for titanium and its alloys as promising candidates for dental implantation due to their bioinert surface. Titanium surface samples were modified using H2O2 solution at different times up to 72 h to boost their bioactivity. According to the results of the field emission scanning electron microscopy test, some nanostructures are formed on the surface of treated titanium samples and increased in size by increasing the time of treatment up to 24 h. After 24 h of application, the sharpness of nanostructures decreased and the micro-cracks and discontinuity in the coating surface increased. The results of the X-ray diffraction study and Raman spectroscopy revealed that anatase (TiO2) was formed on the surface of treated titanium samples. The peak intensity of Raman spectroscopy increased with an improvement in treatment time of up to 24 h and then decreased due to the discontinuity of the coating. Full wettability and ability to form apatite were reached at 6 h of treatment. It is clear that the treatment time has a significant effect on the surface treatment of titanium using the H2O2 solution. [ABSTRACT FROM AUTHOR]

This paper compiles results from three different laboratory studies and employs multivariate regression analyses to model the effect of mixture parameters and concrete hardened properties on saltscaling performance. The correlations between concrete hardened properties and mixture proportions were also studied. The modeled mixture parameters included water-cementitious materials ratio (w/cm), slag cement, and air content. Concrete performance was evaluated through abrasion resistance, sorptivity, compressive strength, and salt scaling tests. According to the results obtained in this study, concrete scaling performance is affected, in the order of importance, by w/cm, slag-cement replacement, and air content. In addition, concrete hardened properties, especially abrasion resistance, were found useful in making reliable salt-scaling predictions. Based on the results derived from the regression analyses and the discussions provided in the reviewed literature, recommendations are given for proportioning of concrete to obtain adequate performance with respect to compressive strength, abrasion resistance, sorptivity, and salt-scaling resistance. In addition, the relationship between concrete properties, ingredients, and effective mechanisms are investigated. [ABSTRACT FROM AUTHOR]