An atomic scale comparison of the reaction of Bioglass® in two types of simulated body fluid

A class of melt quenched silicate glasses, containing calcium, phosphorus and alkali metals, and having the ability to promote bone regeneration and to fuse to living bone, is produced commercially as Bioglass. The changes in structure associated with reacting the bioglass with a body fluid simulant (a buffered Tris(hydroxymethyl)aminomethane growth medium solution or a blood plasma-like salt simulated body fluid) at 37°C have been studied using both high energy and grazing incidence x-ray diffraction. This has corroborated the generic conclusions of earlier studies based on the use of calcia–silica sol-gel glasses whilst highlighting the important differences associated with glass composition; the results also reveal the more subtle effects on reaction rates of the choice of body fluid simulant. The results also indicate the presence of tricalcium phosphate crystallites deposited onto the surface of the glass as a precursor to the growth of hydroxyapatite, and indicates that there is some preferred orientation to their growth

Characterisation of phosphate coacervates for potential biomedical applications

In this study, amorphous (Na2O)x(CaO)0.50−x(P2O5)0.50·yH2O (where x = ∼0.15 and y = ∼3) samples were prepared by a coacervate method. Thermal analysis showed that two types of water molecules were present in the coacervate structures: one type loosely bound and the other part of the phosphate structure. Structural studies using Fourier transform infrared spectroscopy (FTIR) and X-ray total diffraction revealed the samples to have very similar structures to melt-quenched glasses of comparable composition. Furthermore, no significant structural differences were observed between samples prepared using calcium nitrate as the calcium source or those prepared from calcium chloride. A sample containing ∼1 mol% Ag2O was prepared to test the hypothesis that calcium phosphate coacervate materials could be used as delivery agents for antibacterial ions. This sample exhibited significant antibacterial activity against the bacterium Psuedomonas aeruginosa. FTIR data revealed the silver-doped sample to be structurally akin to the analogous silver-free sample

An X-Ray Absorption Spectroscopy Study of Ball-Milled Lithium Tantalate and Lithium Titanate Nanocrystals

Previous work has shown that nanocrystalline samples of lithium tantalate and titanate prepared by high-energy milling show unusually high lithium ion conductivity. Here, we report an X-ray absorption spectroscopy (XAS) study at the Ti K-edge and the Ta L3 edge of samples that have been milled for various lengths of time. For both systems the results show that milling creates amorphous material whose quantity increases with the milling time. The more extensive data for the tantalate shows that milling for only 30 minutes generates ~25% amorphous content in the sample. The content rises to ~60% after 16 hours. It is suggested that it is the motion of the lithium ions through the amorphous content that provides the mechanism for the high ionic conductivity

Structure of a-C:N:H prepared from ammonia

A range of nitrogen-doped amorphous hydrogenated carbon samples (a-C:N-x:H, where x = 3 at.% and x = 7 at.%) have been studied using neutron diffraction, inelastic neutron scattering (INS) and Fourier transform infra-red (FTIR) spectroscopy to obtain detailed information about their atomic-scale structure, particularly the bonding environment of the hydrogen. The results show that the overall atomic scale network structure of the two samples is very similar; however, the hydrogen-bonding sites alter subtly as the nitrogen content of the samples is increased

Involving community pharmacists in pharmacy practice research: experiences of peer interviewing

Background Translation of interest in research into active engagement of community pharmacists as research partners/co-researchers remains a challenge. Involving pharmacists in specific research techniques such as peer interviewing, however, may enhance validity of the results. Objective To enhance community pharmacists’ involvement in pharmacy practice research through peer interview training. Method A subgroup of participants in a multi-phase pharmacy practice research project trained to do peer interviews. These pharmacist interviewers attended a workshop and were mentored. Comments from their feedback forms and ongoing engagement with the Research Associate were thematically analysed. Results Positive themes from five interviewers included the importance of the topic and their wish to learn skills beyond their everyday role. The small group format of the training day helped to build confidence. Interviewers felt their shared professional background helped them to capture relevant comments and probe effectively. There were challenges, however, for interviewers to balance research activities with their daily work. Interviewers experienced difficulty in securing uninterrupted time with interviewees which sometimes affected data quality by ‘rushing’. Conclusion Community pharmacists can be engaged as peer interviewers to the benefit of the volunteers and research team, but must be well resourced and supported