Reversible fluorescent adhesives based on covalent adaptable networks with dynamic AIE crosslinking: in situ visualization of adhesion capability.

A new family of reversible fluorescent adhesives based on Diels-Alder covalent adaptable networks with dynamic AIE crosslinks was developed. The accurate intrinsic correlation between the emission behavior, cross-linking state, and adhesion capability can be established, enabling the in situ visualization of adhesion capacity.

Using call detail records to determine mobility patterns of different socio-demographic groups in the western area of Sierra Leone during early COVID-19 crisis.

Human mobility patterns created from mobile phone call detail records (CDRs) can provide an essential resource in data-poor environments to monitor the effects of health outbreaks. Analysis of this data can be instrumental for understanding the movement pattern of populations allowing governments to set and refine policies to respond to community health risks. Building on CDR mobility analysis techniques, this research set out to test whether combining CDR mobility indicators with socio-economic information can illustrate differences between different socio-economic groups' exposure risks to COVID-19. The work focuses on the Western Area of Sierra Leone which houses the capital Freetown because it lacks existing mobility data and therefore can be a great example of how CDR can be transformed for this use. To determine mobility patterns, we applied the radius of gyration, regularity of movement, and motif types analytics commonly used in CDR research. We then applied a clustering algorithm to these results to understand user trends. Then we compared the results of the three methods with socio-economic status determined from census data in the same geography. The results show the daily movement of cell phone users of lower socio-economic status covered greater distances in the Western Area before and after lockdown, thereby showing a greater risk to COVID-19. The research also shows that groups of higher social status decreased mobility significantly after lockdown and did not return to pre-COVID-19 levels, unlike lower-social status groups.

A Versatile Strategy for Multi-Stimuli-Responsive Fluorescent Material Based on Cross-Linking-Induced Emission: Applications in Encryption.

A versatile strategy for smart fluorescent materials is lacking due to their diverse responding mechanisms and incompatibility of responsive behaviors. Herein an adaptable strategy is presented toward a multi-stimuli-responsive fluorescent material with stage-by-stage responsive behavior by blending linear polymers modified with different stimulus-responsive moieties and AIE cross-linker. Under stimuli, the linear polymer can cross-link with the cross-linker to form networks, which intrinsically restrict the intramolecular rotation of the AIE molecule to induce strong emission. A unified stimuli-responsive mechanism is involved in that various stimuli are transferred through the organized "stimulus-crosslink-emission" process. This strategy ensures the compatibility of different stimuli-responses and the adjustability of stimulus-response behavioral logic. These multi-stimuli-responsive fluorescent materials exhibited strong accessibility and adaptability for information encryption.