Boron-containing bioactive glasses display a strong potential in various biomedical applications lately due to their controllable dissolution rates. In this paper, we prepared a series of BO/SiO-substituded 45S5 bioactive glasses and performed in vitro biomineralization tests with both simulated body fluid and KHPO solutions to evaluate the bioactivities of these glasses as a function of boron oxide to silica substitution. The samples were examined with scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectrometry after immersing them in the two solutions (simulated body fluid and KHPO) up to 3 weeks. It was found that introduction of boron oxide delayed the formation of hydroxyapatite, but all the glasses were shown to be bioactive. Molecular dynamics (MD) simulations were used to complement the experimental efforts to understand the structural changes due to boron oxide to silica substitution by using newly developed partial charge composition-dependent potentials. Local structures around the glass network formers, medium-range structural information, network connectivity, and self-diffusion coefficients of ions were elucidated from MD simulation. Relationships between boron content and glass properties such as structure, density, glass transition temperature, and in vitro bioactivity were discussed in light of both experimental and simulation results.

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In 2011, the Summer School at Georgetown University piloted two service-learning courses to serve the needs of a growing student population during the fall and spring, and to assess the potential for future enrollment growth in the summer term. The pretest data consisted of enrollment figures for summer service-learning courses from 2007 through 2011 and enrollment data for a single service-learning course from four academic semesters in 2010 and 2011. The data set also included a qualitative component: anonymous and confidential student interviews conducted in September and October 2011 to discover and assess the specific interests in enrolling in service learning in summer. The analyzed data clearly demonstrated that the addition of an optional service-learning component to existing classes did not deter students from enrolling; nor did it attract more students to the courses, even though the university, perhaps because of its strong Jesuit tradition, attracts a large population of students predisposed to volunteerism. However, there was one significant and unexpected finding: the qualitative data revealed that the single largest hindrance to enrollments was the absence of information about service-learning opportunities. This finding cut across all semesters, fall, spring, and summer, and was supported by data that demonstrated consistent percentages of enrollments in all three semesters for service-learning courses.