Fan-in/fan-out for heterogeneous 19-core fibers based on metasurfaces with nonuniform phase plates.

In space-division-multiplexed transmission systems, it is essential to realize fan-in/fan-out devices that connect the cores between multicore fibers and single-mode fibers. In this Letter, we propose a metasurface-based fan-in/fan-out device with nonuniform phase plates for heterogeneous 19-core fibers across the full C band. Our results show that an average insertion loss of 0.85 dB and a maximum crosstalk of -25.5 dB can be achieved at 1550 nm. Across the C band, the insertion loss and crosstalk are better than 2.78 dB and -19.96 dB, respectively. The proposed concept can flexibly handle various fiber configurations without additional complexity.

Advancements in the study of inward rectifying potassium channels on vascular cells.

Inward rectifier potassium channels (Kir channels) exist in a variety of cells and are involved in maintaining resting membrane potential and signal transduction in most cells, as well as connecting metabolism and membrane excitability of body cells. It is closely related to normal physiological functions of body and the occurrence and development of some diseases. Although the functional expression of Kir channels and their role in disease have been studied, they have not been fully elucidated. In this paper, the functional expression of Kir channels in vascular endothelial cells and smooth muscle cells and their changes in disease states were reviewed, especially the recent research progress of Kir channels in stem cells was introduced, in order to have a deeper understanding of Kir channels in vascular tissues and provide new ideas and directions for the treatment of related ion channel diseases.

ATP purinergic receptor signalling promotes Sca-1+ cell proliferation and migration for vascular remodelling.

AIMS: Vascular resident stem cells expressing stem cell antigen-1 (Sca-1+ cells) promote vascular regeneration and remodelling following injury through migration, proliferation and differentiation. The aim of this study was to examine the contributions of ATP signalling through purinergic receptor type 2 (P2R) isoforms in promoting Sca-1+ cell migration and proliferation after vascular injury and to elucidate the main downstream signalling pathways. METHODS AND RESULTS: ATP-evoked changes in isolated Sca-1+ cell migration were examined by transwell assays, proliferation by viable cell counting assays and intracellular Ca2+ signalling by fluorometry, while receptor subtype contributions and downstream signals were examined by pharmacological or genetic inhibition, immunofluorescence, Western blotting and quantitative RT-PCR. These mechanisms were further examined in mice harbouring TdTomato-labelled Sca-1+ cells with and without Sca-1+-targeted P2R knockout following femoral artery guidewire injury. Stimulation with ATP promoted cultured Sca-1+ cell migration, induced intracellular free calcium elevations primarily via P2Y2R stimulation and accelerated proliferation mainly via P2Y6R stimulation. Enhanced migration was inhibited by the ERK blocker PD98059 or P2Y2R-shRNA, while enhanced proliferation was inhibited by the P38 inhibitor SB203580. Femoral artery guidewire injury of the neointima increased the number of TdTomato-labelled Sca-1+ cells, neointimal area and the ratio of neointimal area to media area at 3 weeks post-injury, and all of these responses were reduced by P2Y2R knockdown. CONCLUSIONS: ATP induces Sca-1+ cell migration through the P2Y2R-Ca2+-ERK signalling pathway, and enhances proliferation through the P2Y6R-P38-MAPK signalling pathway. Both pathways are essential for vascular remodelling following injury. Video Abstract.

Bidirectional wide-angle waveguide grating antennas with flat-top far-field patterns for optical phased arrays.

To build advanced all solid-state LiDAR, optical phased arrays (OPAs) with a large field of view are highly desirable. As a critical building block, a wide-angle waveguide grating antenna is proposed here. Instead of aiming at the elimination of downward radiation of waveguide grating antennas (WGAs) to improve efficiencies, we in turn utilize the downward radiation and double the range of beam steering. In addition to widened field of views, the steered beams in two directions come from a common set of power splitters, phase shifters and antennas, which greatly reduces chip complexity and power consumption, especially for large-scale OPAs. Beam interference and power fluctuation in the far field due to downward emission can be decreased by specially designed SiO2/Si3N4 antireflection coating. The WGA exhibits balanced emissions in both the upward and downward directions, in which the field of view in each direction is more than 90°. The normalized intensity remains almost the same with a small variation of 10% from -39° to 39° for the upward emission and from -42° to 42° for the downward emission. This WGA is featured by a flat-top radiation pattern in far field, high emission efficiency and good tolerance to device fabrication errors. It holds good potential to achieve wide-angle optical phased arrays.

Immunomagnetic Isolation of the Vascular Wall-Resident CD34+ Stem Cells from Mice.

Resident CD34+ vascular wall-resident stem and progenitor cells (VW-SCs) are increasingly recognized for their crucial role in regulating vascular injury and repair. Establishing a stable and efficient method to culture functional murine CD34+ VW-SCs is essential for further investigating the mechanisms involved in the proliferation, migration, and differentiation of these cells under various physiological and pathological conditions. The described method combines magnetic bead screening and flow cytometry to purify primary cultured resident CD34+ VW-SCs. The purified cells are then functionally identified through immunofluorescence staining and Ca2+ imaging. Briefly, vascular cells from the adventitia of the murine aorta and mesenteric artery are obtained through tissue block attachment, followed by subculturing until reaching a cell count of at least 1 × 107. Subsequently, CD34+ VW-SCs are purified using magnetic bead sorting and flow cytometry. Identification of CD34+ VW-SCs involves cellular immunofluorescence staining, while functional multipotency is determined by exposing cells to a specific culture medium for oriented differentiation. Moreover, functional internal Ca2+ release and external Ca2+ entry is assessed using a commercially available imaging workstation in Fura-2/AM-loaded cells exposed to ATP, caffeine, or thapsigargin (TG). This method offers a stable and efficient technique for isolating, culturing, and identifying vascular wall-resident CD34+ stem cells, providing an opportunity for in vitro studies on the regulatory mechanisms of VW-SCs and the screening of targeted drugs.

Thromboxane-induced contractile response of mesenteric arterioles is diminished in the older rats and the older hypertensive rats.

Nearly all physiological processes are controlled at some level by G-protein-coupled receptor (GPCR) signaling activity. The thromboxane A2 (TXA2) receptor (TP) is a member of the GPCR family. The ultimate effect of TP receptor activation depends on the availability of specific G proteins, which in turn depend on the cell type, tissue, and disease state. However, the roles of the TXA2-TP signaling pathway executed under disease states are poorly defined. In this study, 16-week-spontaneously hypertensive rats (SHR), the 18-month-SHR (OldSHR), and the age-matched Wistar-Kyoto (WKY) rats were used to study the vasoconstriction of mesenteric resistance artery induced by TP-specific agonist, U-46619. Vasoconstriction induced by U-46619 was significantly attenuated in OldWKY and OldSHR rats, and mesenteric arteries with impaired response to U-46619 responded strongly to the adrenergic receptor agonist, phenylephrine. Similar vascular responses to U-46619 were obtained in endothelium-denuded mesenteric arteries. Accordingly, the expression of TP membrane proteins in mesenteric vessels was decreased, and the endogenous TP competitor, 8, 9-EET, in serum was increased, which was partly responsible for the decreased vascular reactivity of U-46619. Decreased TP membrane expression was associated with TP endocytosis, which involved actin cytoskeletal remodeling, including increased ratio of F-actin/G-actin in OldWKY and OldSHR rats. Hence, we studied the effects of TXA2 and its receptors on blood vessels and found that the TXA2-TP prostaglandin signaling pathway was impaired in older adults, which would facilitate the creation of "precision therapeutics" that possess selective efficacy in diseases.

An Automatic Defect Detection System for Petrochemical Pipeline Based on Cycle-GAN and YOLO v5.

Defect detection of petrochemical pipelines is an important task for industrial production safety. At present, pipeline defect detection mainly relies on closed circuit television method (CCTV) to take video of the pipeline inner wall and then detect the defective area manually, so the detection is very time-consuming and has a high rate of false and missed detections. To solve the above issues, we proposed an automatic defect detection system for petrochemical pipeline based on Cycle-GAN and improved YOLO v5. Firstly, in order to create the pipeline defect dataset, the original pipeline videos need pre-processing, which includes frame extraction, unfolding, illumination balancing, and image stitching to create coherent and tiled pipeline inner wall images. Secondly, aiming at the problems of small amount of samples and the imbalance of defect and non-defect classes, a sample enhancement strategy based on Cycle-GAN is proposed to generate defect images and expand the data set. Finally, in order to detect defective areas on the pipeline and improve the detection accuracy, a robust defect detection model based on improved YOLO v5 and Transformer attention mechanism is proposed, with the average precision and recall as 93.10% and 90.96%, and the F1-score as 0.920 on the test set. The proposed system can provide reference for operators in pipeline health inspection, improving the efficiency and accuracy of detection.

Cascade and Fusion: A Deep Learning Approach for Camouflaged Object Sensing.

The demand for the sensor-based detection of camouflage objects widely exists in biological research, remote sensing, and military applications. However, the performance of traditional object detection algorithms is limited, as they are incapable of extracting informative parts from low signal-to-noise ratio features. To address this problem, we propose Camouflaged Object Detection with Cascade and Feedback Fusion (CODCEF), a deep learning framework based on an RGB optical sensor that leverages a cascaded structure with Feedback Partial Decoders (FPD) instead of a traditional encoder-decoder structure. Through a selective fusion strategy and feedback loop, FPD reduces the loss of information and the interference of noises in the process of feature interweaving. Furthermore, we introduce Pixel Perception Fusion (PPF) loss, which aims to pay more attention to local pixels that might become the edges of an object. Experimental results on an edge device show that CODCEF achieved competitive results compared with 10 state-of-the-art methods.

Proteomic analysis of coregulators bound to ERα on DNA and nucleosomes reveals coregulator dynamics.

Chromatin immunoprecipitation studies have mapped protein occupancies at many genomic loci. However, a detailed picture of the complexity of coregulators (CoRs) bound to a defined enhancer along with a transcription factor is missing. To address this, we used biotin-DNA pull-down assays coupled with mass spectrometry-immunoblotting to identify at least 17 CoRs from nuclear extracts bound to 17ß-estradiol (E2)-liganded estrogen receptor-α on estrogen response elements (EREs). Unexpectedly, these complexes initially are biochemically stable and contain certain atypical corepressors. Addition of ATP dynamically converts these complexes to an "activated" state by phosphorylation events, primarily mediated by DNA-dependent protein kinase. Importantly, a "natural" ERE-containing enhancer and nucleosomal EREs recruit similar complexes. We further discovered the mechanism whereby H3K4me3 stimulates ERα-mediated transcription as compared with unmodified nucleosomes. H3K4me3 templates promote specific CoR dynamics in the presence of ATP and AcCoA, as manifested by CBP/p300 and SRC-3 dismissal and SAGA and TFIID stabilization/recruitment.

Analysis of the human endogenous coregulator complexome.

Elucidation of endogenous cellular protein-protein interactions and their networks is most desirable for biological studies. Here we report our study of endogenous human coregulator protein complex networks obtained from integrative mass spectrometry-based analysis of 3290 affinity purifications. By preserving weak protein interactions during complex isolation and utilizing high levels of reciprocity in the large dataset, we identified many unreported protein associations, such as a transcriptional network formed by ZMYND8, ZNF687, and ZNF592. Furthermore, our work revealed a tiered interplay within networks that share common proteins, providing a conceptual organization of a cellular proteome composed of minimal endogenous modules (MEMOs), complex isoforms (uniCOREs), and regulatory complex-complex interaction networks (CCIs). This resource will effectively fill a void in linking correlative genomic studies with an understanding of transcriptional regulatory protein functions within the proteome for formulation and testing of future hypotheses.