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Recently, significant efforts have been devoted to guaranteeing high-quality communication services in fast-moving scenes, such as high-speed trains. The challenges lie in the Doppler effect that shifts the frequency of the transmitted signal. To this end, the recent emergence of spatiotemporal metasurfaces offers a promising solution, which can manipulate electromagnetic waves in time and space domain while being lightweight and cost-effective. Here we introduce deep learning-assisted spatiotemporal metasurfaces to automatically and adaptively neutralize Doppler effect in fast-moving situations. A tandem neural network is used to establish a rapid connection between on-site targets and time-varying series of spatiotemporal metasurfaces, endowing the capability of on-demand beamforming with Doppler effects offset. Moreover, oblique incidence problems are also studied in practice, which can be used for relieving multipath effect. In the microwave experiment, we fabricate the intelligent spatiotemporal metasurfaces and demonstrate the potential to fulfill Doppler-offset beamforming under oblique incidence.

Recently, significant efforts have been devoted to guaranteeing high-quality communication services in fast-moving scenes, such as high-speed trains. The challenges lie in the Doppler effect that shifts the frequency of the transmitted signal. To this end, the recent emergence of spatiotemporal metasurfaces offers a promising solution, which can manipulate electromagnetic waves in time and space domain while being lightweight and cost-effective. Here we introduce deep learning-assisted spatiotemporal metasurfaces to automatically and adaptively neutralize Doppler effect in fast-moving situations. A tandem neural network is used to establish a rapid connection between on-site targets and time-varying series of spatiotemporal metasurfaces, endowing the capability of on-demand beamforming with Doppler effects offset. Moreover, oblique incidence problems are also studied in practice, which can be used for relieving multipath effect. In the microwave experiment, we fabricate the intelligent spatiotemporal metasurfaces and demonstrate the potential to fulfill Doppler-offset beamforming under oblique incidence. [ABSTRACT FROM AUTHOR]

Fatigue driving is one of the primary causative factors of road accidents. It is of great significance to discern, identify and warn drivers in time for traffic safety and reduce traffic accidents. In this paper, a systematic review for the fatigue driving behavior recognition method is developed to analyze its research status and development trends. Firstly, the data information and its application scenarios related to fatigue driving is detailed. Three driving behavior recognition methods based on different types of signal data are summarized and analyzed, and this signal data can be divided into physiological signal characteristics, visual signal characteristics, vehicle sensor data characteristics and multi-data information fusion. By summarizing and comparing the recognition effect of existing fatigue driving recognition methods, combined with deep learning technology, the paper concludes the fatigue driving behavior recognition method based on single data source has some shortcomings such as low accuracy and easy to be affected by external factors, but the recognition method based on multi-feature information fusion can achieve a exhilarated recognition result. Finally, some prospects are given to analyze the development trend of fatigue driving behavior recognition in the future. [ABSTRACT FROM AUTHOR]

Background: Interleukin-33 (IL-33) is reported to be involved in Th2-skewed eosinophilic inflammation. A recent study also found that IL-33 exerted opposite effects on Th17 response in different diseases. However, the role of IL-33 in chronic rhinosinusitis with nasal polyps (NPs) was not explored.Objectives: The purpose of this study was to investigate the expression and function of IL-33 in chronic rhinosinusitis with NPs.Materials and Methods: NP tissues from 60 NP patients and normal tissues of the inferior turbinate from 20 controls were sampled in operation. Immunochemistry was performed to identify eosinophilic or non-eosinophilic NPs. The expressions of IL-33 and Th1/2/17 cytokines were compared between different subtypes of NPs. The effect of IL-33 on Th response was detected in dispersed nasal polyp cells (DNPCs), and the signaling pathways involved in the process were detected using Western blot.Results: The concentration of IL-33 was significantly elevated in both eosinophilic and non-eosinophilic NPs compared with controls. By in vitro study, we found that IL-33 can induce IL-4 and IL-5 production from eosinophilic DNPCs through the PI3K/AKT pathway, whereas IL-33 can induce IL-17 production from non-eosinophilic DNPCs through the ERK1/2 pathway.Conclusion: IL-33 is involved in Th2/Th17 response in NPs. Our study suggests that different types of NPs need a different treatment target. [ABSTRACT FROM AUTHOR]

In this paper, a novel current fed hybrid dual active bridge dc–dc converter is proposed, which is suitable for a low-voltage fuel cell power conditioning system. The high-frequency input current ripple can be reduced to minimum because the input side switches are always switched at 50% duty cycles in spite of the fuel cell voltage and the load variation. Notch filter is used in the voltage feedback path to reduce the low-frequency input current ripple when interfaced with a single-phase inverter load. All of the power devices can achieve zero voltage switching by the proposed control strategy. The mode analysis, the operation principle, zero-voltage switching (ZVS) conditions, and parameter design are given in this paper. A 1 kW prototype has been fabricated to verify the effectiveness of the proposed converter and control strategy. [ABSTRACT FROM PUBLISHER]

Background: Group 2 innate lymphoid cells (ILC2s) promote allergic inflammation by producing interleukin-4 (IL-4), IL-5, IL-9, and IL-13. IL-18 can promote T helper 2 cell (Th2) response by inducing IL-4, and IL-13 production from mast cells and basophils. However, the regulation of IL-18 on ILC2s remained unknown., Objective: To investigate the regulatory role of IL-18 in inducing the type 2 innate lymphoid cells., Methods: Twenty patients with allergic rhinitis (AR) and 20 controls were enrolled. The mRNA and protein levels of IL-18 in serum, as well as the frequencies of ILC2 in peripheral blood mononuclear cells (PBMCs) were measured by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and flow cytometry. The ILC2s were sorted and the mRNA expression of IL-18 receptor in ILC2 was analyzed by real-time PCR. The effects of IL-18 on the proliferation and type 2 cytokine production were detected by tritiated thymidine incorporation test, real-time PCR, and ELISA, respectively., Results: The levels of IL-18 mRNA and protein were significantly higher in AR patients than in the controls (P<0.05). The frequency of ILC2 in peripheral blood was elevated in the AR patients than in the controls. After stimulation by IL-18 and house dust mite (HDM), the expression of IL-18 receptor (IL-18R) by ILC2 was significantly up-regulated. The tritiated thymidine incorporation results showed that IL-18 promoted the proliferation of ILC2 in a dose-dependent manner. IL-18 also induced the expression of IL-5 and IL-13 proteins by ILC2., Conclusion: Our results confirmed -for the first time- the effect of IL-18 in innate immunity, which was demonstrated by direct effect on the differentiation and function of ILC2.