Converting Vertical Vibration of Anisotropic Ratchet Conveyors into Horizontal Droplet Motion

An anisotropic ratchet conveyor is an asymmetric, periodic, micropatterned surface that propels droplets when vibrated with a sinusoidal signal at certain frequencies and amplitudes. For each input frequency, there is a threshold amplitude beyond which the droplet starts to move. In this paper, we study the parameters that initiate droplet motion and the relationship between the input frequency and threshold amplitude among droplets with different volume, density, viscosity, and surface tension. Through this investigation we demonstrate how nondimensionalization reveals consistent behavior for droplets of different volumes. Finally, we propose a compact model that captures the essential features of the system to describe how a pure vertical vibration results in horizontal droplet motion. This model provides an intuitive understanding of the underlying physics and explains how the surface asymmetry is the key for lateral droplet motion

Converting Vertical Vibration of Anisotropic Ratchet Conveyors into Horizontal Droplet Motion

An anisotropic ratchet conveyor is an asymmetric, periodic, micropatterned surface that propels droplets when vibrated with a sinusoidal signal at certain frequencies and amplitudes. For each input frequency, there is a threshold amplitude beyond which the droplet starts to move. In this paper, we study the parameters that initiate droplet motion and the relationship between the input frequency and threshold amplitude among droplets with different volume, density, viscosity, and surface tension. Through this investigation we demonstrate how nondimensionalization reveals consistent behavior for droplets of different volumes. Finally, we propose a compact model that captures the essential features of the system to describe how a pure vertical vibration results in horizontal droplet motion. This model provides an intuitive understanding of the underlying physics and explains how the surface asymmetry is the key for lateral droplet motion

Anomalous Temperature-Dependent Upconversion Luminescence of Small-Sized NaYF₄:Yb³⁺, Er³⁺ Nanoparticles

Size-dependent quantum confinement has important effects on the energy transfer and radiative and nonradiative transitions in nanophosphors. For lanthanide-doped nanoparticles, the confinement effect is induced mostly via electron–phonon interaction, and analysis of temperature-dependent spectroscopic properties provides an effective method for disclosing its underlying mechanism. Herein, an intriguing and unprecedented enhancement of the upconversion luminescence (UCL) at higher temperatures in hexagonal-phase NaYF₄:Yb³⁺, Er³⁺ upconversion nanoparticles (UCNPs) is reported. Moreover, this anomalous UCL enhancement shows a strong dependence on the particle size and becomes more significant for UCNPs with a smaller size. This anomalous thermal behavior is interpreted on the basis of phonon-assisted energy transfer and phonon confinement effect. The findings are relevant to the engineering of the nanostructures of UCNPs and to the further understanding of the UCL mechanism

A Wireless, Regeneratable Cocaine Sensing Scheme Enabled by Allosteric Regulation of pH Sensitive Aptamers

A key challenge for achieving continuous biosensing with existing technologies is the poor reusability of the biorecognition interface due to the difficulty in the dissociation of analytes from the bioreceptors upon surface saturation. In this work, we introduce a regeneratable biosensing scheme enabled by allosteric regulation of a re-engineered pH sensitive anti-cocaine aptamer. The aptamer can regain its affinity with target analytes due to proton-promoted duplex-to-triplex transition in DNA configuration followed by the release of adsorbed analytes. A Pd/PdHx electrode placed next to the sensor can enable the pH regulation of the local chemical environment via electrochemical reactions. Demonstration of a “flower-shaped”, stretchable, and inductively coupled electronic system with sensing and energy harvesting capabilities provides a promising route to designing wireless devices in biointegrated forms. These advances have the potential for future development of electronic sensing platforms with on-chip regeneration capability for continuous, quantitative, and real-time monitoring of chemical and biological markers

A Wireless, Regeneratable Cocaine Sensing Scheme Enabled by Allosteric Regulation of pH Sensitive Aptamers

A key challenge for achieving continuous biosensing with existing technologies is the poor reusability of the biorecognition interface due to the difficulty in the dissociation of analytes from the bioreceptors upon surface saturation. In this work, we introduce a regeneratable biosensing scheme enabled by allosteric regulation of a re-engineered pH sensitive anti-cocaine aptamer. The aptamer can regain its affinity with target analytes due to proton-promoted duplex-to-triplex transition in DNA configuration followed by the release of adsorbed analytes. A Pd/PdHx electrode placed next to the sensor can enable the pH regulation of the local chemical environment via electrochemical reactions. Demonstration of a “flower-shaped”, stretchable, and inductively coupled electronic system with sensing and energy harvesting capabilities provides a promising route to designing wireless devices in biointegrated forms. These advances have the potential for future development of electronic sensing platforms with on-chip regeneration capability for continuous, quantitative, and real-time monitoring of chemical and biological markers

[Bmim]PF₆‑Promoted Ligandless Suzuki–Miyaura Coupling Reaction of Potassium Aryltrifluoroborates in Water

The Suzuki–Miyaura coupling reactions of potassium aryltrifluoroborates with aryl bromides in water are promoted by the addition of [bmim]­PF₆ using Pd­(OAc)₂ as a catalyst and Na₂CO₃ as a base under air. The quantity of [bmim]­PF₆ used is crucial to the efficiency of the catalytic system. A wide range of biaryls and polyaryls can be easily prepared in good to excellent yields

Supplementary document for Printable and Low-cost Perfect Terahertz Absorber Realized by Laser-induced Graphene Metasurface - 6579509.pdf

Comparisons between this work and relevant researc

Representative amperometric foot current transients (A) and summary of foot duration, foot quantal size and mean catecholamine flux (B).

<p>Flux was computed as foot area divided by duration. Error bars represent mean ± SEM (control, 93 events; PACAP, 146 events and L-DOPA, 52 events). *** p<0.001 and ** p<0.01 vs. control, respectively (ANOVA test).</p

Representative TEM images of (A) control and (B) PACAP-treated cells.

<p>Large dense core vesicles are distributed near and far from the plasma membranes. A portion of the nucleus can be seen in the cells. Scale bars = 200 nm. (C) Mean vesicle sizes of control and PACAP-treated cells (n = 17 cells from control group, n = 24 cells for PACAP-treated group; **<i>p</i><0.01 vs. control cells, <i>t-</i>test).</p

Distribution of the decay time in (A) PACAP and (B) L-DOPA treated PC12 cells.

<p>Histograms indicate the existence of two populations of spikes that can be well fitted with two Gaussian functions. PACAP reduces the proportion of rapid spikes of the decay time. Moreover, PACAP shortens the decay time of both fast and slow spikes. In contrast, distributions of decay time of both fast and slow spikes are shifted to the right by the treatment of L-DOPA.</p