Combined modulation format identification and optical signal-to-noise ratio monitoring with high accuracy and generalizability based on a proposed fused module few-shot learning algorithm in dynamic coherent optical transmissions.

Modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring are important portions of optical performance monitoring (OPM) for future dynamic optical networks. In this paper, we proposed a fusion module few-shot learning (FMFSL) algorithm as an improvement upon the ordinary few-shot learning algorithms for image recognition with the specialty in adopting a combination of a dilated convolutional group and an asymmetric convolutional group to advance the feature extraction. FMFSL algorithm is applied in MFI and OSNR monitoring in coherent optical communication systems with its performance investigated in both back-to-back and fiber transmission scenarios using small-scale constellation diagrams. The results show that FMFSL algorithm can achieve 100% accuracy in MFI and higher OSNR monitoring accuracy compared to the few-shot learning algorithms Deep Nearest Neighbor Neural Network (DN4) and Prototypical Nets (PN) with 2.14% and 4.28% for 64QAM and 3.38% and 8.06% for 128QAM, respectively, without much increase in time consumption. Furthermore, the trained FMFSL algorithm remains excellent in MFI and OSNR monitoring without retraining while employed in back-to-back transmission scenarios with smaller OSNR intervals and fiber transmission scenarios with different amounts of Kerr nonlinearity, demonstrating its high capabilities in generalization and robustness. FMFSL algorithm provides a potential solution for OPM in future dynamic optical networks as a novel machine learning tool.

Orally administration of cerium oxide nanozyme for computed tomography imaging and anti-inflammatory/anti-fibrotic therapy of inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic nonspecific disease with unknown etiology. Currently, the anti-inflammatory therapeutic approaches have achieved a certain extent of effects in terms of inflammation alleviation. Still, the final pathological outcome of intestinal fibrosis has not been effectively improved yet. RESULTS: In this study, dextran-coated cerium oxide (D-CeO2) nanozyme with superoxide dismutase (SOD) and catalase (CAT) activities was synthesized by chemical precipitation. Our results showed that D-CeO2 could efficiently scavenge reactive oxide species (ROS) as well as downregulate the pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α, and iNOS) to protect cells from H2O2-induced oxidative damage. Moreover, D-CeO2 could suppress the expression of fibrosis-related gene levels, such as α-SMA, and Collagen 1/3, demonstrating the anti-fibrotic effect. In both TBNS- and DSS-induced colitis models, oral administration of D-CeO2 in chitosan/alginate hydrogel alleviated intestinal inflammation, reduced colonic damage by scavenging ROS, and decreased inflammatory factor levels. Notably, our findings also suggested that D-CeO2 reduced fibrosis-related cytokine levels, predicting a contribution to alleviating colonic fibrosis. Meanwhile, D-CeO2 could also be employed as a CT contrast agent for noninvasive gastrointestinal tract (GIT) imaging. CONCLUSION: We introduced cerium oxide nanozyme as a novel therapeutic approach with computed tomography (CT)-guided anti-inflammatory and anti-fibrotic therapy for the management of IBD. Collectively, without appreciable systemic toxicity, D-CeO2 held the promise of integrated applications for diagnosis and therapy, pioneering the exploration of nanozymes with ROS scavenging capacity in the anti-fibrotic treatment of IBD.

Facilitating Uniform Large-Scale MoS2, WS2 Monolayers, and Their Heterostructures through van der Waals Epitaxy.

The fabrication process for the uniform large-scale MoS2, WS2 transition-metal dichalcogenides (TMDCs) monolayers, and their heterostructures has been developed by van der Waals epitaxy (VdWE) through the reaction of MoCl5 or WCl6 precursors and the reactive gas H2S to form MoS2 or WS2 monolayers, respectively. The heterostructures of MoS2/WS2 or WS2/MoS2 can be easily achieved by changing the precursor from WCl6 to MoCl5 once the WS2 monolayer has been fabricated or switching the precursor from MoCl5 to WCl6 after the MoS2 monolayer has been deposited on the substrate. These VdWE-grown MoS2, WS2 monolayers, and their heterostructures have been successfully deposited on Si wafers with 300 nm SiO2 coating (300 nm SiO2/Si), quartz glass, fused silica, and sapphire substrates using the protocol that we have developed. We have characterized these TMDCs materials with a range of tools/techniques including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), micro-Raman analysis, photoluminescence (PL), atomic force microscopy (AFM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and selected-area electron diffraction (SAED). The band alignment and large-scale uniformity of MoS2/WS2 heterostructures have also been evaluated with PL spectroscopy. This process and resulting large-scale MoS2, WS2 monolayers, and their heterostructures have demonstrated promising solutions for the applications in next-generation nanoelectronics, nanophotonics, and quantum technology.

Oral Delivery of Pterostilbene by L-Arginine-Mediated "Nano-Bomb" Carrier for the Treatment of Ulcerative Colitis.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of unknown aetiology affecting the colon and rectum. Pterostilbene (PS) has been reported as an effective antioxidant and anti-inflammatory agent in preclinical IBD models. However, the therapeutic outcomes of PS are limited by potential side effects associated with the systemic exposure and the modest bioavailability afforded by its oral administration. These issues can be improved with the use of intelligent responsive nanoparticles with the ability of lysosome escape, given their high drug delivery capacity and reducing the side effects. MATERIALS AND METHODS: Herein, the hyaluronic acid (HA)-modified L-arginine CO2 nanoparticles (HA-L-Arg-CO2@NPs) loaded with PS (HA-PS@NPs) are constructed. Under lysosomal pH conditions, HA-PS@NPs liberate CO2 and generate a pH-activated nano-bomb effect to augment the cytosolic delivery of PS. RESULTS: HA-L-Arg-CO2@NPs show great biocompatibility and the excellent ability to target the colon. Using lipopolysaccharide-induced inflammation in vitro, the prominent anti-inflammatory effect of HA-L-Arg-CO2@NPs and HA-PS@NPs is observed. Further, orally administered HA-L-Arg-CO2@NPs and HA-PS@NPs via the colon-targeted chitosan/alginate (CA) hydrogel downregulate pro-inflammatory cytokines and reduce intestinal permeability, yielding significant outcomes in alleviating the symptoms of UC. CONCLUSION: This pH-activated "nano-bomb" carrier with therapeutic effect can be exploited as efficient oral drug carriers for UC treatment.

An oral pH-activated "nano-bomb" carrier combined with berberine by regulating gene silencing and gut microbiota for site-specific treatment of ulcerative colitis.

Ulcerative colitis (UC) is a chronic, relapsing inflammatory bowel disease that features colonic epithelial barrier dysfunction and gut dysbiosis. Preclinical studies demonstrated that inhibiting the overexpression of CD98 via small interfering RNA (siRNA) could alleviate CD98-mediated epithelial barrier dysfunction, and the natural product berberine (BBR) has the ability to improve microbial dysbiosis. However, we lacked the knowledge of whether the combined treatment with CD98 siRNA (siCD98) and BBR could generate an optimal anti-UC efficacy. We hypothesized that the combined therapy may synergize gene silencing and dysbiosis modulating functions of each treatment. To enhance the bioavailability and improve the endo/lysosomal escape of siCD98, we designed hyaluronic acid (HA)-modified chitosan-guanidine-CO2 nanoparticles (HA-CG-CO2@NPs), which could target colonic epithelial and macrophage cells and liberate CO2 at endo/lysosomal pH (nano-bomb effect) for cytosolic siCD98 release. Using lipopolysaccharide-induced inflammation in vitro, we observed a better anti-inflammatory effect of HA-siCD98@NPs and BBR. Furthermore, orally administered HA-siCD98@NPs and BBR (co-loaded in a chitosan/alginate hydrogel) could target the colon, downregulate pro-inflammatory cytokines, and alleviate microbial dysbiosis in a mouse model of UC, yielding a much better efficacy than when administered alone. Collectively, this study provides a promising nanotechnology-based precision targeting strategy for UC treatment.

Enhancing and quantifying spatial homogeneity in monolayer WS2.

Controlling the radiative properties of monolayer transition metal dichalcogenides is key to the development of atomically thin optoelectronic devices applicable to a wide range of industries. A common problem for exfoliated materials is the inherent disorder causing spatially varying nonradiative losses and therefore inhomogeneity. Here we demonstrate a five-fold reduction in the spatial inhomogeneity in monolayer WS2, resulting in enhanced overall photoluminescence emission and quality of WS2 flakes, by using an ambient-compatible laser illumination process. We propose a method to quantify spatial uniformity using statistics of spectral photoluminescence mapping. Analysis of the dynamic spectral changes shows that the enhancement is due to a spatially sensitive reduction of the charged exciton spectral weighting. The methods presented here are based on widely adopted instrumentation. They can be easily automated, making them ideal candidates for quality assessment of transition metal dichalcogenide materials, both in the laboratory and industrial environments.

Voltage tunability of single-spin states in a quantum dot.

Single spins in the solid state offer a unique opportunity to store and manipulate quantum information, and to perform quantum-enhanced sensing of local fields and charges. Optical control of these systems using techniques developed in atomic physics has yet to exploit all the advantages of the solid state. Here we demonstrate voltage tunability of the spin energy-levels in a single quantum dot by modifying how spins sense magnetic field. We find that the in-plane g-factor varies discontinuously for electrons, as more holes are loaded onto the dot. In contrast, the in-plane hole g-factor varies continuously. The device can change the sign of the in-plane g-factor of a single hole, at which point an avoided crossing is observed in the two spin eigenstates. This is exactly what is required for universal control of a single spin with a single electrical gate.