Interplay of Luminophores and Photoinitiators during Synthesis of Bulk and Patterned Luminescent Photopolymer Blends.

Four-dimensional printing with embedded photoluminescence is emerging as an exciting area in additive manufacturing. Slim polymer films patterned with three-dimensional lattices of multimode cylindrical waveguides (waveguide-encoded lattices, WELs) with enhanced fields of view can be fabricated by localizing light as self-trapped beams within a photopolymerizable formulation. Luminescent WELs have potential applications as solar cell coatings and smart planar optical components. However, as luminophore-photoinitiator interactions are expected to change the photopolymerization kinetics, the design of robust luminescent photopolymer sols is nontrivial. Here, we use model photopolymer systems based on methacrylate-siloxane and epoxide homopolymers and their blends to investigate the influence of the luminophore Lumogen Violet (LV) on the photolysis kinetics of the Omnirad 784 photoinitiator through UV-vis absorbance spectroscopy. Initial rate analysis with different bulk polymers reveals differences in the pseudo-first-order rate constants in the absence and presence of LV, with a notable increase (∼40%) in the photolysis rate for the 1:1 blend. Fluorescence quenching studies, coupled with density functional theory calculations, establish that these differences arise due to electron transfer from the photoexcited LV to the ground-state photoinitiator molecules. We also demonstrate an in situ UV-vis absorbance technique that enables real-time monitoring of both waveguide formation and photoinitiator consumption during the fabrication of WELs. The in situ photolysis kinetics confirm that LV-photoinitiator interactions also influence the photopolymerization process during WEL formation. Our findings show that luminophores play a noninnocent role in photopolymerization and highlight the necessity for both careful consideration of the photopolymer formulation and a real-time monitoring approach to enable the fabrication of high-quality micropatterned luminescent polymeric films.

Cognitive Dysfunction: Feasibility of a Brief Intervention to Help Breast Cancer Survivors.

BACKGROUND: Many cancer survivors experience cancer-related cognitive dysfunction (CRCD), which is believed to be the result of multiple contributing biologic, situational, and personal factors. Efficacious, clinically implementable interventions addressing the multifactorial nature of CRCD are needed. OBJECTIVES: This study evaluated the feasibility of an intervention to help breast cancer survivors mitigate the effects of modifiable factors that contribute to CRCD and improve cognitive functioning. METHODS: A single-group pre-/post-test design was used. Treatment fidelity was tracked to evaluate implementability; attendance rates, experience surveys, and homework engagement were used to characterize acceptability. Pre- and post-test cognitive functioning, stress, fatigue, and mood were measured to evaluate preliminary efficacy. FINDINGS: The intervention was implementable and acceptable to participants. Participants made statistically significant improvements.