Optofluidic ring resonator laser with an edible liquid laser gain medium

We demonstrate a biocompatible optofluidic laser with an edible liquid laser gain medium, made of riboflavin dissolved in water. The proposed laser platform is based on a pulled-glass-capillary optofluidic ring resonator (OFRR) with a high Q-factor, resulting in a lasing threshold comparable to that of conventional organic dye lasers that are mostly harmful, despite the relatively low quantum yield of the riboflavin. The proposed biocompatible laser can be realized by not only a capillary OFRR, but also by an optical-fiber-based OFRR that offers improved mechanical stability, and is promising technology for application to in vivo bio-sensing

LaughTalk: Expressive 3D Talking Head Generation with Laughter

Laughter is a unique expression, essential to affirmative social interactions of humans. Although current 3D talking head generation methods produce convincing verbal articulations, they often fail to capture the vitality and subtleties of laughter and smiles despite their importance in social context. In this paper, we introduce a novel task to generate 3D talking heads capable of both articulate speech and authentic laughter. Our newly curated dataset comprises 2D laughing videos paired with pseudo-annotated and human-validated 3D FLAME parameters and vertices. Given our proposed dataset, we present a strong baseline with a two-stage training scheme: the model first learns to talk and then acquires the ability to express laughter. Extensive experiments demonstrate that our method performs favorably compared to existing approaches in both talking head generation and expressing laughter signals. We further explore potential applications on top of our proposed method for rigging realistic avatars.Comment: Accepted to WACV202

A hydrostatic pressure-driven passive micropump enhanced with siphon-based autofill function.

Autonomous and self-powered micropumps are in critical demand for versatile cell- and tissue-based applications as well as for low-cost point-of-care testing (POCT) in microfluidics fields. The hydrostatic pressure-driven passive micropumps are simple and widely used, but they cannot maintain steady and continuous flow for long periods of time. Here, we propose a hydrostatic pressure-driven passive micropump enhanced with siphon-based autofill function, which can realize the autonomous and continuous perfusion with well-controlled steady flow over an extended time without electric power consumption. The characterization results reveal that both the cycle number in one refilling loop and the siphon diameter will affect the refilling time. Furthermore, this micropump also enables multiplexed medium delivery under either the same or different flow conditions with high flexibility. The system was validated using an in vitro vasculogenesis model over the course of several days. Most importantly, the device can consistently provide steady medium perfusion for up to 5 days at a predefined hydrostatic pressure drop without the need for supplemental medium changes. We believe that this hydrostatic pressure-driven passive micropump will become a critical module for a broad range of sophisticated microfluidic operations and applications

Control of Interface Defects for Efficient and Stable Quasi-2D Perovskite Light-Emitting Diodes Using Nickel Oxide Hole Injection Layer.

Metal halide perovskites (MHPs) have emerged as promising materials for light-emitting diodes owing to their narrow emission spectrum and wide range of color tunability. However, the low exciton binding energy in MHPs leads to a competition between the trap-mediated nonradiative recombination and the bimolecular radiative recombination. Here, efficient and stable green emissive perovskite light-emitting diodes (PeLEDs) with an external quantum efficiency of 14.6% are demonstrated through compositional, dimensional, and interfacial modulations of MHPs. The interfacial energetics and optoelectronic properties of the perovskite layer grown on a nickel oxide (NiO x ) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate hole injection interfaces are investigated. The better interface formed between the NiO x /perovskite layers in terms of lower density of traps/defects, as well as more balanced charge carriers in the perovskite layer leading to high recombination yield of carriers are the main reasons for significantly improved device efficiency, photostability of perovskite, and operational stability of PeLEDs

The influence of outflows on the 1/f-like luminosity fluctuations

In accretion systems, outflows may have significant influence on the luminosity fluctuations. In this paper, following the Lyubarskii's general scheme, we revisit the power spectral density of luminosity fluctuations by taking into account the role of outflows. Our analysis is based on the assumption that the coupling between the local outflow and inflow is weak on the accretion rate fluctuations. We find that, for the inflow mass accretion rate $\dot M \propto r^{s}$, the power spectrum of flicker noise component will present a power-law distribution $p(f) \propto f^{-(1+4s/3)}$ for advection-dominated flows. We also obtain descriptions of $p(f)$ for both standard thin discs and neutrino-cooled discs, which show that the power-law index of a neutrino-cooled disc is generally larger than that of a photon-cooled disc. Furthermore, the obtained relationship between $p(f)$ and $s$ indicates the possibility of evaluating the strength of outflows by the power spectrum in X-ray binaries and gamma-ray bursts. In addition, we discuss the possible influence of the outflow-inflow coupling on our results.Comment: 6 pages, 1 figure, accepted for publication in MNRA

Cordycepin induces human lung cancer cell apoptosis by inhibiting nitric oxide mediated ERK/Slug signaling pathway

Nitric oxide (NO) is an important signaling molecule and a component of the inflammatory cascade. Besides, it is also involved in tumorigenesis. Aberrant upregulation and activation of the ERK cascade by NO often leads to tumor cell development. However, the role of ERK inactivation induced by the negative regulation of NO during apoptosis is not completely understood. In this study, treatment of A549 and PC9 human lung adenocarcinoma cell lines with cordycepin led to a reduction in their viability. Analysis of the effect of cordycepin treatment on ERK/Slug signaling activity in the A549 cell line revealed that LPS-induced inflammatory microenvironments could stimulate the expression of TNF-α, CCL5, IL-1β, IL-6, IL-8 and upregulate NO, phospho-ERK (p-ERK), and Slug expression. In addition, constitutive expression of NO was observed. Cordycepin inhibited LPS-induced stimulation of iNOS, NO, p-ERK, and Slug expression. L-NAME, an inhibitor of NOS, inhibited p-ERK and Slug expression. It was also found that cordycepin-mediated inhibition of ERK downregulated Slug, whereas overexpression of ERK led to an upregulation of Slug levels in the cordycepin-treated A549 cells. Inhibition of Slug by siRNA induced Bax and caspase-3, leading to cordycepin-induced apoptosis. Cordycepin-mediated inhibition of ERK led to a reduction in phospho-GSK3β (p-GSK3β) and Slug levels, whereas LiCl, an inhibitor of GSK3β, upregulated p-GSK3β and Slug. Overall, the results obtained indicate that cordycepin inhibits the ERK/Slug signaling pathway through the activation of GSK3β which, in turn, upregulates Bax, leading to apoptosis of the lung cancer cells

Human induced pluripotent stem cell-derived endothelial cells in thrombosis-on-a-chip devices

A microfluidic thrombosis-on-a-chip platform was developed to compare the pro-thrombotic response of healthy and inflamed monolayers of human umbilical vein endothelial cells (HUVECs) and human induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs). Inflammation was induced by exposing the endothelial cells (ECs) to an inflammatory cytokine Tumor Necrosis Factor-α (TNF-α). After human whole blood perfusion at an arterial shear rate, the platelet coverage and average clot size were determined. Healthy endothelium showed a lower platelet coverage than inflamed endothelium. A minor difference was measured for both platelet coverage and average clot sizes on inflamed HUVECs versus hiPSC-ECs

High-Performance Perovskite Light-emitting Diodes via Morphological Control of Perovskite Film

Solution-processable perovskite materials have garnered tremendous attention because of their excellent charge carrier mobility, possibility of a tunable optical bandgap, and high photoluminescence quantum efficiency (PLQE). In particular, the uniform morphology of a perovskite film is the most important factor in realizing perovskite light-emitting diodes (PeLEDs) with high efficiency and full-coverage electroluminescence (EL). In this study, we demonstrate highly efficient PeLEDs that contain a perovskite film with a uniform morphology by introducing HBr into the perovskite precursor. The introduction of HBr into the perovskite precursor results in a perovskite film with a uniform, continuous morphology because the HBr increases the solubility of the inorganic component in the perovskite precursor and reduces the crystallization rate of the perovskite film upon spin-coating. Moreover, PeLEDs fabricated using perovskite films with a uniform, continuous morphology, which were deposited using 6 vol% HBr in a dimethylformamide (DMF)/hydrobromic acid (HBr) cosolvent, exhibited full coverage of the green EL emission. Finally, the optimized PeLEDs fabricated with perovskite films deposited using the DMF/HBr cosolvent exhibited a maximum luminance of 3490 cd m(-2) (at 4.3 V) and a luminous efficiency of 0.43 cd A(-1) (at 4.3 V).ope