Intra-articular glucocorticoid injections are effective in controlling inflammation and pain in arthritides but restricted by short duration of action and risk of joint degeneration. Controlled drug release using biocompatible hydrogels offers a unique solution, but limitations of in situ gelation restrict their application. Gellan sheared hydrogels (GSHs) retain the advantages of hydrogels, however their unique microstructures lend themselves to intra-articular application - capable of shear thinning under force but restructuring at rest to enhance residence.
View Article and Find Full Text PDFBacterial swarming is a complex phenomenon in which thousands of self-propelled rod-shaped cells move coherently on surfaces, providing an excellent example of active matter. However, bacterial swarming is different from most studied examples of active systems because single isolated cells do not move, while clusters do. The biophysical aspects underlying this behavior are unclear.
View Article and Find Full Text PDFThe primary goal of the present study was to determine the economic relationship between heroin and social reinforcement in rats: are they substitutes, independents, or complements? In Experiment 1, one group of rats was given a budget of responses that they could allocate between heroin and social reinforcement offered at various combinations of prices. A second group chose between two levers that each resulted in social reinforcement at varying prices when pressed. There was no relationship between the relative allocation of responses between heroin and social reinforcement and changes in their relative prices, indicating that these reinforcers are best viewed as independents.
View Article and Find Full Text PDFUnlabelled: Flagella are complex, trans-envelope nanomachines that localize to species- specific cellular addresses. Here we study the localization dynamics of the earliest stage of basal body formation in using a fluorescent fusion to the C-ring protein FliM. We find that basal bodies do not exhibit dynamic subunit exchange and are largely stationary at steady state, consistent with flagellar assembly through the peptidoglycan.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2024
Microbial communities such as biofilms are commonly found at interfaces. However, it is unclear how the physical environment of interfaces may contribute to the development and behavior of surface-associated microbial communities. Combining multimode imaging, single-cell tracking, and numerical simulations, here, we found that activity-induced interface bulging promotes colony biofilm formation in swarms presumably via segregation and enrichment of sessile cells in the bulging area.
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