Numerical Investigation for the Resin Filling Behavior during Ultraviolet Nanoimprint Lithography of Subwavelength Moth-Eye Nanostructure

Accurate analysis of the resin filling process into the mold cavity is necessary for the high-precision fabrication of moth-eye nanostructure using the ultraviolet nanoimprint lithography (UV-NIL) technique. In this research, a computational fluid dynamics (CFD) simulation model was proposed to reveal resin filling behavior, in which the effect of boundary slip was considered. By comparison with the experimental results, a good consistency was found, indicating that the simulation model could be used to analyze the resin filling behavior. Based on the proposed model, the effects of process parameters on resin filling behavior were analyzed, including resin viscosity, inlet velocity and resin thickness. It was found that the inlet velocity showed a more significant effect on filling height than the resin viscosity and thickness. Besides, the effects of boundary conditions on resin filling behavior were investigated, and it was found the boundary slip had a significant influence on resin filling behavior, and excellent filling results were obtained with a larger slip velocity on the mold side. This research could provide guidance for a more comprehensive understanding of the resin filling behavior during UV-NIL of subwavelength moth-eye nanostructure

Curcumin encapsulation and protection based on lysozyme nanoparticles

Curcumin possesses antioxidant, anti‐inflammatory, and other properties. However, this compound exhibits low bioavailability because of its poor solubility and stability. In this paper, lysozyme nanoparticles were fabricated through solvent evaporation, and then, the solubilization and protection capability of curcumin were investigated. Lysozyme nanoparticles were characterized by dynamic light scattering technique, atomic force microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The load capacity and stability in thermal environment were further explored. Results showed that the lysozyme nanoparticle displayed a spherical structure (127.9 ± 2.12 nm) with favorable distribution. The solubility of curcumin can increase to 22 μg/mL. After encapsulation by lysozyme nanoparticles, the retentive curcumin can reach up to 67.9% and 30.25% at 25°C and 50°C, respectively, significantly higher than that of free curcumin. Meanwhile, experiments on DPPH free radicals indicated the curcumin loaded by lysozyme nanoparticle possessed higher free radical scavenging activity than that of free curcumin with same treatments. The results confirmed that lysozyme nanoparticles exhibit potential applications in solubilizing and protecting the environment‐sensitive hydrophobic functional components

A peripheral subepithelial network for chemotactile processing in the predatory sea slug Pleurobranchaea californica.

Many soft-bodied animals have extensive peripheral nervous systems (PNS) with significant sensory roles. One such, the sea slug Pleurobranchaea californica, uses PNS computations in its chemotactile oral veil (OV) in prey tracking, averaging olfactory stimuli across the OV to target likely source direction, or "stimulus place". This suggests a peripheral subepithelial network (SeN) interconnecting sensory sites to compute the directional average. We pursued anatomy and connectivity of previously described ciliated putative sensory cells on OV papillae. Scanning electron microscopy (SEM) confirmed paddle-shaped cilia in clusters. Anti-tubulin and phalloidin staining showed connections to branching nervelets and muscle fibers for contraction and expansion of papillae. Ciliary cell processes could not be traced into nerves, consistent with sensory transmission to CNS via secondary afferents. Anti-tyrosine hydroxylase-stained ciliated cells in clusters and revealed an at least partially dopaminergic subepithelial network interconnecting clusters near and distant, connections consistent with PNS averaging of multiple stimulated loci. Other, unidentified, SeN neurotransmitters are likely. Confirming chemotactile functions, perfusible suction electrodes recorded ciliary spiking excited by both mechanical and appetitive chemical stimuli. Stimuli induced sensory nerve spiking like that encoding stimulus place. Sensory nerve spikes and cilia cluster spikes were not identifiable as generated by the same neurons. Ciliary clusters likely drive the sensory nerve spikes via SeN, mediating appetitive and stimulus place codes to CNS. These observations may facilitate future analyses of the PNS in odor discrimination and memory, and also suggest such SeNs as potential evolutionary precursors of CNS place-coding circuitry in the segmented, skeletonized protostomes and deuterostomes

Curcumin encapsulation and protection based on lysozyme nanoparticles

Curcumin possesses antioxidant, anti‐inflammatory, and other properties. However, this compound exhibits low bioavailability because of its poor solubility and stability. In this paper, lysozyme nanoparticles were fabricated through solvent evaporation, and then, the solubilization and protection capability of curcumin were investigated. Lysozyme nanoparticles were characterized by dynamic light scattering technique, atomic force microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The load capacity and stability in thermal environment were further explored. Results showed that the lysozyme nanoparticle displayed a spherical structure (127.9 ± 2.12 nm) with favorable distribution. The solubility of curcumin can increase to 22 μg/mL. After encapsulation by lysozyme nanoparticles, the retentive curcumin can reach up to 67.9% and 30.25% at 25°C and 50°C, respectively, significantly higher than that of free curcumin. Meanwhile, experiments on DPPH free radicals indicated the curcumin loaded by lysozyme nanoparticle possessed higher free radical scavenging activity than that of free curcumin with same treatments. The results confirmed that lysozyme nanoparticles exhibit potential applications in solubilizing and protecting the environment‐sensitive hydrophobic functional components

Spontaneous spiking activity in a focally recorded cilia cluster and the lack thereof in adjacent skin.

Spontaneous spiking activity in a focally recorded cilia cluster and the lack thereof in adjacent skin.</p

SEM images of papillae surfaces.

A: Three clusters of cilia on a lobe. B: Each cluster is surrounded by numerous tubercles, some of which in this image are ruptured (dashed ellipse). C: There are about 100 cilia in each cluster, with all showing the dilated heads of paddle cilia. D: Paddle cilia-like structures (arrows) are observed within the several broken tubercles of B, above. Scale bars: A, 25 μm; B, 10 μm; C, 3 μm; and D, 2 μm.</p

Mechanoceptive responses of papillae at perfusion onset.

A: “On” responses from papillae at onset of ASW flow. The records are from 24 recordings of different papillae in three different animals. Immediately upon the step change in pressure in the suction electrode with ASW perfusion, brief bursts of spikes occurred. Responses quickly adapted while flow was maintained. Recordings from skin adjacent to papillae showed little spontaneous and no induced mechanosensitive activity (not shown). Perfusion offset (downward arrowhead) was 5 seconds after onset (upward arrowhead) for most (19 out of 24) recordings, and for 5 recordings it was 2 seconds after onset. B: Papillar spike frequencies for 1 second time-windows before and after onset of perfusion, and before perfusion offset (box plots show distributions of the firing frequencies, including mean, interquartile distribution, and outliers). Averaged pre-perfusion baseline firing frequency was 1.625 ± 0.31 Hz (median: 1.0 Hz, standard error: 0.311), increasing to 11.30 ± 0.90 Hz (median: 12.0 Hz, standard error: 0.897) at perfusion onset. Spike activity rapidly adapted to lower firing frequency (4.92 ± 0.75 Hz; median: 3.5 Hz, standard error: 0.752) measured at 1 second before perfusion offset. These effects were significant (Wilcoxon Signed-Rank tests p < 0.00002 for perfusion onset response vs. pre-perfusion (*) and for perfusion onset vs. adaptation (**), and slightly less significant p < 0.0003 for pre-perfusion vs. adaptation).</p

Efferent spikes in papillae from LOVN stimulation.

Shown are 7 of 30 records where two papillae were recorded simultaneously during single LOVN stimuli. Following the stimulus artifacts in mid-traces, single spikes (arrows) appeared in papillae at variable latencies. The spikes in the papillar pair had nearly identical latencies. Spikes sometimes failed in both pairs (record 7), or more often, either failed to appear in the papilla of the upper trace pairs (e.g., record 5) or failed to fully invade (record 6).</p

High-Property Refractive Index and Bio-Sensing Dual-Purpose Sensor Based on SPPs

A high-property plasma resonance-sensor structure consisting of two metal-insulator-metal (MIM) waveguides coupled with a transverse ladder-shaped nano-cavity (TLSNC) is designed based on surface plasmon polaritons. Its transmission characteristics are analyzed using multimode interference coupling mode theory (MICMT), and are simulated using finite element analysis (FEA). Meanwhile, the influence of different structural arguments on the performance of the structure is investigated. This study shows that the system presents four high-quality formants in the transmission spectrum. The highest sensitivity is 3000 nm/RIU with a high FOM* of 9.7 &times; 105. In addition, the proposed structure could act as a biosensor to detect the concentrations of sodium ions (Na+), potassium ions (K+), and the glucose solution with maximum sensitivities of 0.45, 0.625 and 5.5 nm/mgdL&minus;1, respectively. Compared with other structures, the designed system has the advantages of a simple construction, a wide working band range, high reliability and easy nano-scale integration, providing a high-performance cavity choice for refractive index sensing and biosensing devices based on surface plasmons