Achieving Ideal Magnetic Light Emission with Electric-Type Emitters.

Optical magnetic dipole (MD) emission predominantly relies on emitters with significant MD transitions, which, however, rarely exist in nature. Here, we propose a strategy to transform electric dipole (ED) emission to a magnetic one by elegantly coupling an ED emitter to a silicon nanoparticle exhibiting a strong MD resonance. This emission mode transformation enables an artificially ideal magnetic dipole source with an MD purity factor of up to 99%. The far-field emission patterns of such artificial MD sources were experimentally measured, which unambiguously resolved their magnetic-type emission origin. This study opens the path to achieving ideal magnetic dipole emission with nonmagnetic emitters, largely extending the availability of magnetic light emitters conventionally limited by nature. Beyond the fundamental significance in science, we anticipate that this study will also facilitate the development of magnetic optical nanosource and enable potential photonic applications relying on magnetic light emission.

Greatly Enhanced Plasmon-Exciton Coupling in Si/WS2/Au Nanocavities.

A strong light-matter interaction is highly desirable from the viewpoint of both fundamental research and practical application. Here, we propose a dielectric-metal hybrid nanocavity composed of a silicon (Si) nanoparticle and a thin gold (Au) film and investigate numerically and experimentally the coupling between the plasmons supported by the nanocavity and the excitons in an embedded tungsten disulfide (WS2) monolayer. When a Si/WS2/Au nanocavity is excited by the surface plasmon polariton generated on the surface of the Au film, greatly enhanced plasmon-exciton coupling originating from the hybridization of the surface plasmon polariton, the mirror-image-induced magnetic dipole, and the exciton modes is clearly revealed in the angle- or size-resolved scattering spectra. A Rabi splitting as large as ∼240 meV is extracted by fitting the experimental data with a coupled harmonic oscillator model containing three oscillators. Our findings open new horizons for constructing nanoscale photonic devices by exploiting dielectric-metal hybrid nanocavities.

Novel Guanidinium-Functionalized Stigmasterol for Bile Salt Binding and Serum Cholesterol Reduction: Synthesis, Interaction Mechanisms, and In Vivo Function.

A novel amphiphilic guanidyl-functionalized stigmasterol hydrochloride (GFSH) was designed and synthesized as bile salt sequestrants for cholesterol reduction. GFSH exhibited a considerable in vitro capacity for bile salt binding in gastrointestinal digestion and alleviated hypercholesterolemia in vivo. GFSH spontaneously interacted with sodium cholate via synergistic electrostatic, hydrophobic, and hydrogen-bonding interactions. The effects of GFSH on serum cholesterol reduction in mice fed a high-fat-high-cholesterol diet were explored by measuring the expression of key transcription factors related to bile acid metabolism. GFSH produced a dose-dependent reduction in weight gain, hepatic fat accumulation, and fecal and blood markers. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot analyses demonstrated GFSH-induced expression of hepatic CYP7A, LXRα, and LDL-R. GFSH exerts the cholesterol-lowering activity by inducing the bile acid metabolism.

Quantitative study of peripapillary retinal nerve fiber layer thickness and peripapillary vessel density in patients with different stages of Parkinson's disease.

AIM: To observe the changes in the thickness of peripapillary retinal nerve fiber layer (pRNFL) and peripapillary vessel density (pVD) in patients with different stages of Parkinson's disease (PD). METHODS: Totally 47 patients (47 eyes) with primary PD were divided into the mild group and the moderate-to-severe group according to Hoehn & Yahr (H&Y) stage. Among them, there were 27 cases (27 eyes) in mild group and 20 cases (20 eyes) in moderate-to-severe group. And 20 cases (20 eyes) who were included in the control group were healthy people who came to our hospital for health screening at the same time. All participants underwent optical coherence tomography angiography (OCTA) examinations. The pRNFL thickness, total vessel density (tVD) and capillary vessel density (cVD) of the optic disc in average, superior half, inferior half, superior nasal (SN), nasal superior (NS), nasal inferior (NI), inferior nasal (IN), inferior temporal (IT), temporal inferior (TI), temporal superior (TS), and superior temporal (ST) were measured. One-way ANOVA was used to compare the differences of optic disc parameters among the three groups, and Pearson and Spearman correlations were used to analyze the correlation between pRNFL, pVD and the disease duration, H&Y stage and UPDRS-III score in patients with PD, respectively. RESULTS: There were significant differences in pRNFL thickness in average, superior half, inferior half, SN, NS, IN, IT and ST quadrants among the three groups (P<0.05). In PD group, the pRNFL thickness in average, superior half, inferior half, NS and IT quadrants were negatively correlated with H&Y stage and UPDRS-III score, respectively (P<0.05). There were statistically significant differences in the cVD of whole image, inferior half, NI and TS quadrants, the tVD of the whole image, inferior half, and peripapillary among the three groups (P<0.05). In PD group, the tVD of whole image and the cVD of NI and TS quadrants were negatively correlated with the H&Y stage, respectively (P<0.05); the cVD of TS quadrant was negatively correlated with UPDRS-III score (P<0.05). CONCLUSION: The thickness of pRNFL in PD patients is significantly decreased, and it is negatively correlated with H&Y stage and UPDRS-III score. With the increase of the severity of the disease, the pVD parameters in PD patients increase at first in the mild group, and then decrease in the moderate-to-severe group, and negatively correlate with H&Y stage and UPDRS-III score.

Ultralow Threshold Lasing from a Continuous-Wave-Pumped SiNx/CsPbBr3/Ag Thin Film Mediated by the Whispering Gallery Modes of a SiO2 Microsphere.

Thin-film pervoskite lasers driven by a continuous wave (CW) laser with ultralow thresholds, which is crucial for the development of on-chip electrically driven lasers, have not yet been realized owing to the low excitation power density of the CW laser. Here, we reported the CW-laser-pumped lasing from a thin film of CsPbBr3 quantum dots (QDs) sandwiched by a SiNx and a Ag thin film and mediated by the whispering gallery modes of a SiO2 microsphere. The stable photoluminescence from CsPbBr3 QDs with a quantum efficiency of ∼45% is realized by encapsulating with a thin SiNx film. Upon CW-laser pumping, lasing from the whispering gallery modes with a threshold of ∼11.6 W/cm2 is successfully demonstrated at room temperature. The strong localization of electric field achieved in the particle-on-film system, which is revealed in the numerical simulations and lifetime measurements, plays a crucial role in the realization of the ultralow threshold lasing. Our findings open a new avenue for designing photostable CW-laser-pumped pervoskite lasers.

Optical Introduction and Manipulation of Plasmon-Exciton-Trion Coupling in a Si/WS2/Au Nanocavity.

Strong plasmon-exciton coupling, which has potential applications in nanophotonics, plasmonics, and quantum electrodynamics, has been successfully demonstrated by using metallic nanocavities and two-dimensional materials. Dynamical control of plasmon-exciton coupling strength, especially by using optical methods, remains a big challenge although it is highly desirable. Here, we report the optical introduction and manipulation of plasmon-exciton-trion coupling realized in a dielectric-metal hybrid nanocavity, which is composed of a silicon (Si) nanoparticle and a thin gold (Au) film, with an embedded tungsten disulfide (WS2) monolayer. We employ scattering and photoluminescence spectra to characterize the coupling strength between plasmons and excitons in Si/WS2/Au nanocavities constructed by using Si nanoparticles with different diameters. We enhance the plasmon-exciton and plasmon-trion coupling strength by injecting excitons and trions into the WS2 monolayer with a 488 nm laser beam. It is revealed that the emission intensities of excitons and trions with respect to the reference WS2 monolayer can be modified through the change in the coupling strength induced by the laser light. Interestingly, the coupling strength between the plasmons and the excitons/trions can be manipulated from weak to strong coupling regime by simply increasing the laser power, which is clearly resolved in the scattering spectra of Si/WS2/Au nanocavities. More importantly, the plasmon-exciton-trion coupling induced by the laser light is confirmed by the energy exchange between excitons and trions. Our findings indicate the possibility for optically manipulating plasmon-exciton interaction and suggest the practical applications of dielectric-metal hybrid nanocavities in nanoscale plasmonic devices.

Circular RNA circ_0000228 promotes the malignancy of cervical cancer via microRNA-195-5p/ lysyl oxidase-like protein 2 axis.

Circular RNAs (circRNAs) are a class of novel non-coding RNAs that are vital in modulating gene expression and biological processes. Nevertheless, in cervical cancer (CC), the role of circRNA is much less investigated. In this work, circ_0000228 expression in CC is measured and circ_0000228's function and related mechanism are investigated. Quantitative real-time quantitative polymerase chain reaction (qRT-PCR) was utilized to examine the expression levels of circ_0000228, microRNA-195-5p (miR-195-5p) and lysyl oxidase-like protein 2 (LOXL2). Western blotting was employed to examine LOXL2 protein expression in CC cell lines. CC cell lines with circ_0000228 knockdown were constructed, and the CCK-8 experiment and Transwell experiment were executed to investigate the effect of circ_0000228 on the malignant characteristics of CC cells. Furthermore, a dual-luciferase reporter gene experiment was applied to validate the targeting relationship between circ_0000228 and miR-195-5p, miR-195-5p and LOXL2. In this study, we demonstrated that circ_0000228 showed a remarkable up-modulation in CC tissues and cell lines. Circ_0000228 knockdown repressed the growth and metastatic potential of CC cells. Mechanistically, circ_0000228 facilitated CC progression through sponging miR-195-5p and up-modulating LOXL2 expression. We conclude that circ_0000228 is an oncogenic circRNA, which participates in promoting CC progression via regulating the miR-195-5p/LOXL2 axis.

Circular RNA HIPK3 plays a carcinogenic role in cervical cancer progression via regulating miR-485-3p/FGF2 axis.

Circular RNA (circRNA) is an endogenous RNA molecule with a stable closed-loop structure. The circular RNA HIPK3 (circHIPK3) is highly expressed in hepatocellular carcinoma and facilitates tumor growth. However, its role in cervical cancer (CC) and its regulatory mechanisms are not well-studied. This study aimed for investigating the function of circHIPK3 on proliferation and metastasis of CC cells. In this study, quantitative real-time PCR assay was adopted to delve into the circHIPK3 expression in CC cell lines. Cell counting kit-8 and colony formation assays were used to evaluate the influence of overexpression and knockdown of circHIPK3 on CC cell proliferation. Dual-luciferase reporter assay was employed to probe into the binding of miR-485-3p to circHIPK3 and miR-485-3p to the 3' untranslated region (UTR) of fibroblast growth factor 2 (FGF2), respectively. FGF2 protein expression was detected by western blot analysis. This study confirmed that circHIPK3 was highly expressed in CC tissues. Overexpressed circHIPK3 could remarkably expedite the proliferation, migration and invasion of SiHa cells, and knocking down circHIPK3 could significantly impede the proliferation, migration and invasion of HeLa cells. MiR-485-3p can directly bind to circHIPK3 and the 3'UTR of FGF2. Overexpression of circHIPK3 triggered the upregulation of FGF2 expression while knockdown of circHIPK3 reduced FGF2 expression in CC cells, and the transfection of miR-485-3p mimics reversed the upregulation of FGF2 expression and enhanced malignant phenotypes in CC cells with overexpressed circHIPK3.

[Effect of Naoxintong capsules on calcitonin gene-related peptide of vascular dementia in rats].

OBJECTIVE: To explore the effect of Naoxintong capsules on learning and dysmnesia and calcitonin gene-related peptide (CGRP) about vascular dementia (VD) in rats. METHODS: The model of vascular dementia rats were built by middle cerebral artery occlusion (MCAO), and then the rats were randomly divided into a Naoxintong group (that was traditional Chinese medicine group,TCM group), a Western medicine group, a model group, a sham operation group, and a normal group. After corresponding treatment, the rat so behaviors were detected by Morris water maze experiment to obtain their performance record of learning and memory. The changes of cell morphology were detected by Nissl stain. The expression of CGRP in the hippocampus was measured with immunohistochemical staining. RESULTS: The masculine cells about CGRP of the TCM group were more than those of the model one (P<0.05). Naoxintong capsules improved the ability of learning and memory in vascular dementia rats, prevented the pyramidal cells on CA1 field in hippocampus from decreasing, increased the number of masculine cells about CGRP, and deceased the gray scale value. CONCLUSION: Naoxintong capsules can raise the number of masculine nerve cells of CGRP, protect the pyramidal cells of VD rats, and lessen their learning and dysmnesia, which may be part of the mechanism of improving learning and memory capacity of VD model in rats.