A large-scale genetic screen identifies genes essential for motility in Agrobacterium fabrum.

The genetic and molecular basis of flagellar motility has been investigated for several decades, with innovative research strategies propelling advances at a steady pace. Furthermore, as the phenomenon is examined in diverse bacteria, new taxon-specific regulatory and structural features are being elucidated. Motility is also a straightforward bacterial phenotype that can allow undergraduate researchers to explore the palette of molecular genetic tools available to microbiologists.

Responsive Fluorophore Aggregation Provides Spectral Contrast for Fluorescence Lifetime Imaging.

Fluorophores experience altered emission lifetimes when incorporated into and liberated from macromolecules or molecular aggregates; this trend suggests the potential for a fluorescent, responsive probe capable of undergoing self-assembly and aggregation and consequently altering the lifetime of its fluorescent moiety to provide contrast between the active and inactive probes. We developed a cyanobenzothioazole-fluorescein conjugate (1), and spectroscopically examined the lifetime changes caused by its reduction-induced aggregation in vitro. A decrease in lifetime was observed for compound 1 in a buffered system activated by the biological reducing agent glutathione, thus suggesting a possible approach for designing responsive self-aggregating lifetime imaging probes.

Resolving population dynamics and interactions of multiple triplet excitons one molecule at a time.

Resolving the population dynamics of multiple triplet excitons on time scales comparable to their lifetimes is a key challenge for multiexciton harvesting strategies, such as singlet fission. We show that this information can be obtained from fluorescence quenching dynamics and stochastic kinetic modeling simulations of single nanoparticles comprising self-assembled aggregated chains of poly(3-hexylthiophene) (P3HT). These multichromophoric structures exhibit the elusive J-aggregate type excitonic coupling leading to delocalized intrachain excitons that undergo facile triplet formation mediated by interchain charge transfer states.

Methodologic Considerations for Collecting Patient-reported Outcomes from Unselected Surgical Patients.

Background: The impact of surgery on health is only appreciated long after hospital discharge. Furthermore, patients' perceptions of postoperative health are not routinely ascertained. The authors instituted the Systematic Assessment and Targeted Improvement of Services Following Yearlong Surgical Outcomes Surveys (SATISFY-SOS) registry to evaluate patients' postoperative health based on patient-reported outcomes (PROs).