Gold nanoclusters protected by 3-mercaptopropionic acid (MPA-Au nanoclusters) were prepared by citrate-reduction of hydrogen tetrachloroaurate(III) in the presence of sodium 3-mercaptopropionate. Color of the dispersions of MPA-Au nanoclusters changed from red to purple by addition of hydrochloric acid and returned from purple to red by addition of an aqueous sodium hydroxide solution. This reversible response can be attributed to synchronized changes between dispersion and ordering of MPA-Au nanoclusters, determined by transmission electron microscopy. Gold nanoclusters protected by poly(acrylic acid) (PAA-Au nanoclusters) were prepared by UV irradiation of an aqueous solution of hydrogen tetrachloroaurate(III) in the presence of poly(sodium acrylate). The pH-dependent spectral change observed for MPA-Au was not observed for PAA-Au. UV-Vis absorption spectra of colloidal dispersions of PAA-Au nanoclusters after addition of hydrochloric acid and an aqueous sodium hydroxide solution were in good agreement with each other, suggesting the stability of PAA-Au nanoclusters to pH change.

The various lines of calcaneal fractures indicate their complex nature and make their treatment challenging. There is still much debate regarding the position and direction of these fracture lines, even for the primary fracture line. The computed tomographybased finite element model is known to provide accurate predictions of fracture loads and virtual fracture locations for the femur and distal radius. This study aimed to establish how to predict the calcaneus fracture lines using the computed tomography-based finite element model for patients with contralateral calcaneal fractures and to investigate whether the predicted lines were similar to those of the fractured calcaneus. The calcanei of five men and two women aged 44-77 years (average age, 60 years) with contralateral calcaneal fractures were analyzed. To assess the precision of the predicted fracture lines of the contralateral calcanei, they were compared with the fracture locations found by three-dimensional models of the calcanei. The fracture lines of the finite element model simulated the actual fracture lines and diagnosed joint depression types of fractures (five cases) and tongue types (two cases), but only under certain conditions for each case. This trial simulated calcaneal fractures using a patient-specific computed tomography-based nonlinear finite element model. Therefore, we suggest that it is possible to reproduce calcaneal fractures using the finite element model. It was possible to predict with precision the actual calcaneal fracture for each patient and to reproduce fracture conditions. Therefore, this method is valuable because it can provide an understanding of the pathomechanism of calcaneal fractures. ß

No abstract

No abstract