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Supercritical CO2-assisted impregnation (SCI) offers a sustainable route for embedding functional small molecules into polymer substrates, but its capacity to direct additive localization, interfacial organization, and solid-state structure, key determinants of optical, barrier, and controlled-release performance in multifunctional polymer composites and coatings, remains insufficiently understood. Herein, we elucidate how SCI processing governs the sorption, interfacial interactions, spatial localization, and release kinetics of vanillin, a model solid-phase bioactive compound, within semicrystalline cellulose. SCI enabled vanillin loadings ranging from 0.15 to 0.60 g g–1, with addition of polar cosolvents enhancing uptake by nearly 10-fold relative to neat CO2. By adjusting cosolvent environment and batch time, SCI directs the formation of distinct additive domains: surface-confined crystalline deposits at short times, bulk-dispersed amorphous regions at intermediate times, and recrystallized nanostructured domains once local additive concentrations exceed the dispersive capacity of cellulose. FTIR spectroscopic, X-ray photoelectron spectroscopic, X-ray diffraction, calorimetric, and electron microscopic characterization reveal that these SCI-driven interfacial interactions and phase states govern cellulose composite hydration, moisture-sorption hysteresis, and UV-shielding performance, where UVB transmittance ranges from 4–6% (surface crystalline) to 13–15% (matrix-embedded crystalline). Release experiments conducted in FDA/EU food simulants show that amorphous vanillin exhibits rapid, diffusion-controlled dissolution, reaching equilibrium (∼33 μg mL–1) within 180 min, whereas crystalline vanillin dispersed throughout the matrix exhibits delayed, anomalous release, showing a 30 min lag and ∼90 μg mL–1 equilibrium concentration after ∼10,000 min. Collectively, these results establish SCI as a versatile materials engineering platform that couples supercritical-fluid processing with control over interfacial chemistry and solid-state organization, enabling the design of sustainable cellulose-based composites with programmable optical, hygroscopic, and transport properties. 

Abstract The inner-shell ionization of selenophene at 120 eV produces a rich array of fragmentation dynamics, including many originating from Auger-Meitner processes. In this report, three-dimensional velocity-map imaging and covariance analysis were used to identify and characterize over 50 distinct selenophene fragmentation channels. The majority resulted in two or three ‘heavy’ products containing selenium or carbon, many of which had identical mass-to-charge ratios but different chemical compositions due to the degree of hydrogenation and the selenium isotope involved. Covariance analysis was used to isolate these reaction channels and to provide estimates of their relative yields. In combination with prior similar studies on thiophene and furan, the current results indicate that the nature of the heteroatom significantly influences the charge redistribution and bond cleavage dynamics induced by the Auger-Meitner process, and demonstrate the sensitivity of inner-shell ionization dynamics to the molecular and electronic structures of heterocyclic systems. 

Balance between excitatory and inhibitory activity is essential for nervous system function. Neuroactive substances like nicotine can disrupt this balance and hyperactivate dopaminergic circuits, with combined effects on behavior and neural activity. We use Drosophila larvae to examine nicotine-induced, linked behavioral changes over multiple time scales by integrating high-resolution locomotor analysis with genetic and pharmacological manipulations. Acute nicotine exposure produces concentration-dependent hyperactivity. Manipulations of the dopaminergic system establish dopamine as the main mediator for motor responses, and further exploration establishes the γ lobe of the mushroom body as a key site for nicotine integration. Experiments with long-term and repetitive nicotine exposure suggest sustained circuit excitability. Finally, nicotine exposure history induces nicotine preference, highlighting experience-dependent plasticity contributing to addiction-like behaviors. These results help establish Drosophila larvae as a model organism to elucidate how neuroactive substances reconfigure neural circuits and behavior. 

We use the Pound–Drever–Hall (PDH) technique to characterize the frequency stability of a microwave-frequency surface acoustic wave resonator-based sensor. The multi-mode acoustic resonator is integrated in a notch geometry with a transmission line, all fabricated on Y-cut lithium niobate. We measure the amplitude and phase of the resonator's transfer function and the PDH signal across the resonator's full spectral range. We use these measurements to emphasize the differences between the PDH measurement and a standard Phase-Locked Loop (PLL) technique. As compared to a PLL, we demonstrate that PDH is insensitive to phase error and exhibits a reduced Allan deviation of the center frequency measurement, in each case by up to an order of magnitude. The method rejects spurious effects and background frequency drift, demonstrating the enhancements possible with PDH-based measurements, which can be realized in a wide range of microwave-frequency resonator-based sensors and devices.