An exploration of plastic deformation dependence of cell viability and adhesion in metallic implant materials

The relationship between cell viability and adhesion behavior, and micro-deformation mechanisms was investigated on austenitic 316L stainless steel samples, which were subjected to different amounts of plastic strains (5%, 15%, 25%, 35% and 60%) to promote a variety in the slip and twin activities in the microstructure. Confocal laser scanning microscopy (CLSM) and field emission scanning electron microscopy (FESEM) revealed that cells most favored the samples with the largest plastic deformation, such that they spread more and formed significant filopodial extensions. Specifically, brain tumor cells seeded on the 35% deformed samples exhibited the best adhesion performance, where a significant slip activity was prevalent, accompanied by considerable slip-twin interactions. Furthermore, maximum viability was exhibited by the cells seeded on the 60% deformed samples, which were particularly designed in a specific geometry that could endure greater strain values. Overall, the current findings open a new venue for the production of metallic implants with enhanced biocompatibility, such that the adhesion and viability of the cells surrounding an implant can be optimized by tailoring the surface relief of the material, which is dictated by the micro-deformation mechanism activities facilitated by plastic deformation imposed by machining.

Family background and individual measures as predictors of Turkish primary school children's academic achievement

The primary purpose of this study was to predict academic grade point averages (GPAs) of Turki primary school children, using family background and individual measures (sociometric standing, self-reported loneliness, and social efficacy) as predictors. We hypothesized that these two measures would explain the wide variation in GPA for samples differing with respect to sex and paternal education. Regression analyses with male and female subsamples revealed that the background measures explained twice as much variance in GPA, popularity, and loneliness for girls as for boys. Another finding was that the background measures explained a greater proportion of the variance in GPA for children with less- versus more-educated fathers, whereas individual measures explained a greater proportion of the variance for children with more as opposed to less educated fathers.