Bilateral Filter Regularized L2 Sparse Nonnegative Matrix Factorization for Hyperspectral Unmixing

Hyperspectral unmixing (HU) is one of the most active hyperspectral image (HSI) processing research fields, which aims to identify the materials and their corresponding proportions in each HSI pixel. The extensions of the nonnegative matrix factorization (NMF) have been proved effective for HU, which usually uses the sparsity of abundances and the correlation between the pixels to alleviate the non-convex problem. However, the commonly used L 1 / 2 sparse constraint will introduce an additional local minima because of the non-convexity, and the correlation between the pixels is not fully utilized because of the separation of the spatial and structural information. To overcome these limitations, a novel bilateral filter regularized L 2 sparse NMF is proposed for HU. Firstly, the L 2 -norm is utilized in order to improve the sparsity of the abundance matrix. Secondly, a bilateral filter regularizer is adopted so as to explore both the spatial information and the manifold structure of the abundance maps. In addition, NeNMF is used to solve the object function in order to improve the convergence rate. The results of the simulated and real data experiments have demonstrated the advantage of the proposed method

Performance Study of Origami Crash Tubes Based on Energy Dissipation History

Thin-walled tubes are widely used as energy-absorbing components in traffic vehicles, which can absorb part of the energy in time by using the plastic deformation of the components during collision so as to reduce the damage of the vehicle body and improve the overall safety and reliability of traffic vehicles. The prefolded design of thin-walled tube components can guide it to achieve the ideal energy dissipation performance according to the preset damage path, so the related research based on origami tubes has attracted a lot of attention. Since the geometry of the origami tubes is controlled by many parameters and stress and deformation is a complex nonlinear damage process, most of the previous studies adopted the method of case analysis to carry out numerical simulation and experimental verification of the relevant influence parameters. This paper makes a new exploration of this kind of problem and focuses on solving the related technical problems in three aspects: 1. The automatic model modeling and 3D display based on parameters are proposed; 2. System integration using Python programming to automatically generate the data files of ABAQUS for finite element simulation was realized, and we sorted the finite element analysis results into an artificial intelligence analysis data set; 3. Clustering analysis of the energy consumption history of the data set is carried out using a machine learning algorithm, and the key design parameters that affect the energy consumption history are studied in depth. The sensitivity of the energy absorption performance of the origami tubes with multi-morphology patterns to the crease spacing is studied, and it is shown that the concave–convex crease spacing distribution with a distance larger than 18 mm could be used to activate specific crushing modes. In the optimal case, its initial peak force is reduced by 66.6% compared to uniformly spaced creases, while the average crushing force is essentially the same. Furthermore, this paper finds a new path to optimizing the design of parameters for origami tubes including a multi-morphology origami pattern from the perspective of energy dissipation

The generation of glioma organoids and the comparison of two culture methods

Abstract Background The intra‐ and inter‐tumoral heterogeneity of gliomas and the complex tumor microenvironment make accurate treatment of gliomas challenging. At present, research on gliomas mainly relies on cell lines, stem cell tumor spheres, and xenotransplantation models. The similarity between traditional tumor models and patients with glioma is very low. Aims In this study, we aimed to address the limitations of traditional tumor models by generating patient‐derived glioma organoids using two methods that summarized the cell diversity, histological features, gene expression, and mutant profiles of their respective parent tumors and assess the feasibility of organoids for personalized treatment. Materials and Methods We compared the organoids generated using two methods through growth analysis, immunohistological analysis, genetic testing, and the establishment of xenograft models. Results Both types of organoids exhibited rapid infiltration when transplanted into the brains of adult immunodeficient mice. However, organoids formed using the microtumor method demonstrated more similar cellular characteristics and tissue structures to the parent tumors. Furthermore, the microtumor method allowed for faster culture times and more convenient operational procedures compared to the Matrigel method. Discussion Patient‐derived glioma organoids, especially those generated through the microtumor method, present a promising avenue for personalized treatment strategies. Their capacity to faithfully mimic the cellular and molecular characteristics of gliomas provides a valuable platform for elucidating tumor biology and evaluating therapeutic modalities. Conclusion The success rates of the Matrigel and microtumor methods were 45.5% and 60.5%, respectively. The microtumor method had a higher success rate, shorter establishment time, more convenient passage and cryopreservation methods, better simulation of the cellular and histological characteristics of the parent tumor, and a high genetic guarantee

Circular RNA MAPK4 (circ-MAPK4) inhibits cell apoptosis via MAPK signaling pathway by sponging miR-125a-3p in gliomas

BackgroundRecent evidences have shown that circular RNAs (circRNAs) are frequently dysregulated and play paramount roles in various cancers. circRNAs are abundant in central nervous system (CNS); however, few studies describe the clinical significance and role of circRNAs in gliomas, which is the most common and aggressive primary malignant tumor in the CNS.MethodsA bioinformatics analysis was performed to profile and screen the dyregulated circRNAs during early neural development. Quantitative real-time PCR was used to detect the expression of circ-MAPK4 and target miRNAs. Glioma cells were transfected with circ-MAPK4 siRNAs, then cell proliferation, apoptosis, transwell assays, as well as tumorigenesis and TUNEL assays, were performed to examine effect of circ-MAPK4 in vitro and vivo. Biotinylated-circ-MAPK4 probe based pull-down assay was conducted to confirm the relationship between circ-MAPK4 and miR-125-3p.ResultsIn this study, we identified a circRNA, circ-MAPK4 (has_circ_0047688), which was downregulated during early neural differentiation. In gliomas, circ-MAPK4 acted as an oncogene, was inversely upregulated and linked to clinical pathological stage of gliomas (P < 0.05). Next, we verified that circ-MAPK4 promoted the survival and inhibited the apoptosis of glioma cells in vitro and in vivo. Furthermore, we proved that circ-MAPK4 was involved in regulating p38/MAPK pathway, which affected glioma proliferation and apoptosis. Finally, miR-125a-3p, a miRNA exhibited tumor-suppressive function through impairing p38/MAPK pathway, which was increased by inhibiting circ-MAPK4 and could be pulled down by circ-MAPK4. Inhibition of miR-125a-3p could partly rescue the increased phosphorylation levels of p38/MAPK and the elevated amount of apoptosis inducing by knockdown of circ-MAPK4.ConclusionsOur findings suggest that circ-MAPK4 is a critical player in glioma cell survival and apoptosis via p38/MAPK signaling pathway through modulation of miR-125a-3p, which can serve as a new therapeutic target for treatment of gliomas