The ability to regulate small molecule chemistry in vivo will enable new avenues of exploration in imaging and pharmacology. However, realization of these goals will require reactions with high specificity and precise control. Here we demonstrate photocontrol over the highly specific Staudinger–Bertozzi ligation in vitro and in vivo. Our simple approach, photocaging the key phosphine atom, allows for the facile production of reagents with photochemistry that can be engineered for specific applications. The resulting compounds, which are both stable and efficiently activated, enable the spatial labeling of metabolically introduced azides in vitro and on live zebrafish.

A lack of preparedness for college-level coursework has been shown to negatively impact student success rates in STEM. Remedial instruction has been the most widespread approach to helping at-risk students attain college-level competencies; however, studies have shown that remediation has had null or negative impacts on degree completion for students placed into these courses. This study examines two decades worth of data from one institution to evaluate the efficacy of course pathway diversification as an alternative model to traditional remediation on general chemistry students' firstand second-semester outcomes. In this approach, students with low mathematics placement exam scores take a separate lecture offering of general chemistry I with a corequisite support course (GCI-S) that is offered in parallel with the mainstream course (GCI-M). The course content across these offerings is the same, and successful students in either course are rejoined in a common general chemistry II course (GCII) in the subsequent semester. Our results indicate that first-semester outcomes for at-risk students have improved markedly since the inception of GCI-S relative to non-at-risk students. However, these improvements are not as apparent in GCII. Additionally, while the achievement gap in first-semester general chemistry outcomes between GCI-S and GCI-M students has improved, corresponding achievement gaps in GCII have worsened. We discuss the implications of our findings in ways that might guide the efforts of others in better supporting our most vulnerable students in chemistry.

Several studies have highlighted the positive effects that active learning may have on student engagement and performance. However, the influence of active learning strategies is mediated by several factors, including the nature of the learning environment and the cognitive level of in-class tasks. These factors can affect different dimensions of student engagement such as the nature of social processing in student groups, how knowledge is used and elaborated upon by students during in-class tasks, and the amount of student participation in group activities. In this study involving four universities in the US, we explored the association between these different dimensions of student engagement and the cognitive level of assigned tasks in five distinct general chemistry learning environments where students were engaged in group activities in diverse ways. Our analysis revealed a significant association between task level and student engagement. Retrieval tasks often led to a significantly higher number of instances of no interaction between students and individualistic work, and a lower number of knowledge construction and collaborative episodes with full student participation. Analysis tasks, on the other hand, were significantly linked to more instances of knowledge construction and collaboration with full group participation. Tasks at the comprehension level were distinctive in their association with more instances of knowledge application and multiple types of social processing. The results of our study suggest that other factors such as the nature of the curriculum, task timing, and class setting may also affect student engagement during group work.

A diverse and highly qualified chemistry teaching workforce is critical for preparing equally diverse, qualified STEM professionals. Here, we analyze National Center for Education Statistics (NCES) Schools and Staffing Survey (SASS) data to provide a demographic comparison of the U.S. secondary chemistry teaching population in high-needs and non-high-needs public schools as well as private schools during the 2011–2012 academic year. Our analysis reveals that the chemistry teaching workforce is predominantly white and significantly lacks in-field degrees or certification across school types, though high-needs and private schools are most affected by this lack of teacher qualification. Given these results, we attempt to retrosynthetically identify the pathway yielding a qualified chemistry teaching workforce to draw attention to the various steps in this scheme where reform efforts on the part of individual faculty, academic institutions, and organizations can be concentrated.