This study examines the surface-assisted photoalignment effect of dye-doped liquid-crystal films having a homogeneous alignment. Observations made using a polarizing optical microscope, a scanning electronic microscope, and an atomic force microscope confirm that the morphology of laser-induced surface-adsorbed dyes at the command surface strongly affects the orientation of liquid crystals (LC's) in a manner that depends significantly on the intensity and duration of the pumping. In weak-intensity regime, a homogeneous and fine layer of adsorbed dyes competes with a layer of ripple structure in reorienting LC's. These two effects dominantly cause LC's to reorient perpendicular and parallel to the polarization direction of the pump beam in the early and late stages, respectively. In the high-intensity regime, rough and inhomogeneous ribbonlike adsorbents produced by rapid and random aggregation and adsorption form on the top of the preformed microgrooves, reorienting LC's irregularly. This surface morphology does not enable photoalignment.

This study applies a low-cost solvothermal method to synthesize all-inorganic (lead-free cesium tin halide) perovskite quantum dots (AIPQDs) and to fabricate AIPQD-doped lasers with cholesteric liquid crystal (CLC) lasing cavities. The lasers present highly qualified lasing features of low threshold (150 nJ/pulse) and narrow line width (0.20 nm) that are attributed to the conjunction of the suppression of photoluminescence (PL) loss caused by the quantum confinement of AIPQDs and the amplification of PL caused by the band-edge effect of the CLC-distributed feedback resonator. In addition, the lasers possess highly flexible lasing-wavelength tuning features and a long-term stability under storage at room temperature and under high humidity given the protective role of CLC. These advantages are difficult to confer to typical light-emitting perovskite devices. Given these merits, the AIPQD-doped CLC laser device has considerable potential applications in optoelectronic and photonic devices, including lighting, displays, and lasers.

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Eight new chrysogenolides (A-H (1-8)) and seven known (9-15) 3,5-dimethylorsellinic acid derived meroterpenoids were isolated from the solid substrate fermentation cultures of a Huperzia serrata endophytic fungus, Penicillium chrysogenum MT-12. The structures of the new compounds were elucidated by interpretation of spectroscopic and spectrometric data (1D and 2D NMR, IR, and HRESIMS). The absolute configurations of 1-4 were determined by single-crystal X-ray crystallographic analysis, and those of 5-8 were assigned on the basis of experimental and calculated electronic circular dichroism spectra. Compounds 3, 4, 6, 11, and 12 showed inhibition of nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophage cells with IC values in the range of 4.3-78.2 μM (positive control, indomethacin, IC = 33.6 ± 1.4 μM).

This study investigates high-resolution photoinduced biphotonic holographic gratings in azo-dye-doped liquid crystal films. A biphotonic grating (BG) is formed under the illumination of one linearly polarized green light with the simultaneous irradiation of an interference pattern created by two linearly polarized red lights. This study ascribes the formation of this grating to two mechanisms. One mechanism is the green-light-inducing strong dye absorption followed by adsorption through the trans–cis isomerization; the other mechanism is the inhibition effect of adsorption induced by the red light through the cis–trans inverse isomerization. These produce a twisted nematic structure-modulated pattern, which, in turn, causes the BG. Additional experiments demonstrate that the formed BGs are electrically switchable and thermally erasable.

No abstract

Background Many circRNAs have been reported to play important roles in cancer development and have the potential to serve as a novel class of biomarkers for clinical diagnosis. However, the role of circRNAs in esophageal carcinoma (EC) remains unclear. In the current study, we investigated the potential role of circPVT1 in esophageal carcinoma. Methods Quantitative real-time PCR was performed to detect circPVT1 levels. CircPVT1-specific siRNA or plasmids were used to knock down or overexpression the target RNA. Hoechst Staining was implemented to evaluate the ratio of cell apoptosis. Transwell migration assays were carried out to study the effects of circPVT1 on esophageal squamous cell carcinoma cell invasion. RegRNA 2.0 was used for bioinformatics analysis. The expression levels of Pax-4, Pax-6, PPARα and PPAR-γ were assessed using Western blot. Results In the present study, we demonstrated a significant up-regulation of circPVT1 levels in EC tissues and cancer cell lines. The levels of circPVT1 decreased significantly when the cells were maintained to over-confluence. These results suggested a potential role for circPVT1 in cell proliferation. In addition, overexpressing circPVT1 in TE-10 cell promoted invasive ability of cancer cell. In contrast, siRNA knockdown of circPVT1 inhibited this phenomenon, leading to increased apoptosis levels of TE-10 cell. What’s more, miR-4663 had the effect of inhibiting tumor growth by downregulated Paxs and upregulated PPARs. Whereas, after the addition of circPVT1, this effect no longer worked, suggesting that circPVT1 may affect the malignancy of the tumor by affecting miRNA and regulating the levels of Paxs and PPARs. Conclusions Collectively, our study reveals a critical role for circPVT1 in esophageal carcinoma, which may provide new insights of this circRNA as a biomarker for the diagnosis and treatment target of EC.

This investigation elucidates for the first time electrically controllable random lasers below the threshold voltage in dye-doped liquid crystal (DDLC) cells with and without adding an azo-dye. Experimental results show that the lasing intensities and the energy thresholds of the random lasers can be decreased and increased, respectively, by increasing the applied voltage below the Fréedericksz transition threshold. The below-threshold-electric-controllability of the random lasers is attributable to the effective decrease of the spatial fluctuation of the orientational order and thus of the dielectric tensor of LCs by increasing the electric-field-aligned order of LCs below the threshold, thereby increasing the diffusion constant and decreasing the scattering strength of the fluorescence photons in their recurrent multiple scattering. This can result in the decrease in the lasing intensity of the random lasers and the increase in their energy thresholds. Furthermore, the addition of an azo-dye in DDLC cell can induce the range of the working voltage below the threshold for the control of the random laser to reduce.