Ferroptosis, a new non-necrotizing programmed cell death (PCD), is driven by iron-dependent phospholipid peroxidation. Ferroptosis plays a key role in secondary traumatic brain injury and secondary ...spinal cord injury and is closely related to inflammation, immunity, and chronic injuries. The inhibitors against ferroptosis effectively improve iron homeostasis, lipid metabolism, redox stabilization, neuronal remodeling, and functional recovery after trauma. In this review, we elaborate on the latest molecular mechanisms of ferroptosis, emphasize its role in secondary central nervous trauma, and update the medicines used to suppress ferroptosis following injuries.
Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Despite great improvements in the therapeutic regimen, relapse and leptomeningeal dissemination still pose great challenges to ...the long‐term survival of MB patients. Developing more effective strategies has become extremely urgent. In recent years, a number of malignancies, including MB, have been found to contain a subpopulation of cancer cells known as cancer stem cells (CSCs), or tumor initiating/propagating cells. The CSCs are thought to be largely responsible for tumor initiation, maintenance, dissemination, and relapse; therefore, their pivotal roles have revealed them to be promising targets in MB therapy. Our growing understanding of the major medulloblastoma molecular subgroups and the derivation of some of these groups from specific stem or progenitor cells adds additional layers to the CSC knowledge base. Herein we review the current knowledge of MB stem cells, highlight the molecular mechanisms relating to MB relapse and leptomeningeal dissemination, and incorporate these with the need to develop more effective and accurate therapies for MB patients.
In this paper,we review the current knowledge of MB stem cells (MBSCs), highlight the molecular mechanisms in relation to MB relapse and LMD, and relate these to the need to develop more effective therapies for MB patients.
Abstract
A theoretical explanation for the working mechanism of polarization conversion metasurfaces (PCMs) is provided based on characteristic mode analysis (CMA). When a PCM is illuminated by ...electromagnetic waves, certain characteristic modal currents will be excited. When the modal currents satisfy the polarization conversion condition, the PCM will generate the cross polarization as reflection. The proposed theory is verified by the characteristic mode investigation of typical PCMs by numerical simulation.
•The elastic modulus and Poisson's ratio of the designed metamaterial were investigated.•The relationship between the formation of band gaps and lattice configuration was demonstrated.•The SMP-based ...metamaterial can be switched between different deformation states to adjust the band gap.•The band gap could be adjusting real-time by changing the ambient temperature.
Artificial designed metamaterials have attracted widespread attention because of its unique lattice structure and special physical properties. In this work, a chiral auxetic metamaterial with adjustable band gap function is designed based on the shape memory polymer (SMP) with special thermomechanical property. Theory and finite element methods are used to investigate the relationship between the elastic modulus, Poisson's ratio and lattice parameters of the chiral metamaterial. Moreover, the dispersion curves of the metamaterial under different strain states and temperature field are studied by finite element method. The evolution processes of the band gap with the variation of configuration and environmental temperature are systematically revealed. The results show that the elastic modulus can be tailored by adjusting the geometric parameters of the lattice, and the Poisson's ratio is -1. The band gap could be real-time adjusted by external stimuli (mechanical loadings, temperature field). Based on the relationship between the geometric parameters and the band gap, the required properties of metamaterial can be customized. Moreover, the vibration control ability of the metamaterial can be further optimized by adjusting the strain of metamaterial and the temperature. The method of designing metamaterials with tunable and programmable mechanical properties and acoustic functions provides a meaningful reference for the development of metamaterials with potential applications.
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Purpose
To develop a portable MR perfusion phantom for quality‐controlled assessment and reproducibility of arterial spin labeled (ASL) perfusion measurement.
Methods
A 3D‐printed perfusion phantom ...was developed that mimics the branching of arterial vessels, capillaries, and a chamber containing cellulose sponge representing tissue characteristics. A peristaltic pump circulated distilled water through the phantom, and was first evaluated at 300, 400, and 500 mL/min. Longitudinal reproducibility of perfusion was performed using 2D pseudo‐continuous ASL at 20 post‐label delays (PLDs, ranging between 0.2 and 7.8 s at 0.4‐s intervals) over a period of 16 weeks, with three repetitions each week. Multi‐PLD data were fitted into a general kinetic model for perfusion quantification (f) and arterial transit time (ATT). Intraclass correlation coefficient was used to assess intersession reproducibility.
Results
MR perfusion signals acquired in the 3D‐printed perfusion phantom agreed well with the experimental conditions, with progressively increasing signal intensities and decreasing ATT for pump flow rates from 300 to 500 mL/min. The perfusion signal at 400 mL/min and the general kinetic model–derived f and ATT maps were similar across all PLDs for both intrasession and intersession reproducibility. Across all 48 experimental time points, the average f was 75.55 ± 3.83 × 10−3 mL/mL/s, the corresponding ATT was 2.10 ± 0.20 s, and the T1 was 1.84 ± 0.102 s. Intraclass correlation coefficient was 0.92 (95% confidence interval 0.83–0.97) for f, 0.96 (0.91–0.99) for ATT, and 0.94 (0.88–0.98) for T1, demonstrating excellent reproducibility.
Conclusion
A simple, portable 3D‐printed perfusion phantom with excellent reproducibility of 2D pseudo‐continuous ASL measurements was demonstrated that can serve for quality‐controlled and reliable measurements of ASL perfusion.
Abstract
In order to solve the problem that it is difficult to judge whether the air targets detected by infrared detectors at different locations are the same target, an infrared air target fusion ...algorithm is proposed. The algorithm constructs a cylindrical coordinate system, introduces two infrared sensors into the cylindrical coordinate system. Then introduces the aerial target information which including azimuth elevation into the cylindrical coordinate system, thus establishing the association between the targets. Finally, the correctness of the algorithm is verified by three rounds of experiments. The simulation results show that the error of the algorithm is within the reservation threshold and has certain engineering application value.
(–)-Epigallocatechin-3-O-gallate (EGCG), the most abundant component of catechins in tea (Camellia sinensis (L.) O. Kuntze), plays a role against viruses through inhibiting virus invasiveness, ...restraining gene expression and replication. In this paper, the antiviral effects of EGCG on various viruses, including DNA virus, RNA virus, coronavirus, enterovirus and arbovirus, were reviewed. Meanwhile, the antiviral effects of the EGCG epi-isomer counterpart (+)-gallocatechin-3-O-gallate (GCG) were also discussed.
Tumor-associated macrophages (TAMs) constitute a large population of glioblastoma and facilitate tumor growth and invasion of tumor cells, but the underlying mechanism remains undefined. In this ...study, we demonstrate that chemokine (C-C motif) ligand 8 (CCL8) is highly expressed by TAMs and contributes to pseudopodia formation by GBM cells. The presence of CCL8 in the glioma microenvironment promotes progression of tumor cells. Moreover, CCL8 induces invasion and stem-like traits of GBM cells, and CCR1 and CCR5 are the main receptors that mediate CCL8-induced biological behavior. Finally, CCL8 dramatically activates ERK1/2 phosphorylation in GBM cells, and blocking TAM-secreted CCL8 by neutralized antibody significantly decreases invasion of glioma cells. Taken together, our data reveal that CCL8 is a TAM-associated factor to mediate invasion and stemness of GBM, and targeting CCL8 may provide an insight strategy for GBM treatment.
With excellent electrical conductivity as well as low thermal conductivity, Zintl phases have been well investigated for possible thermoelectric applications, from which some materials configured ...with special structures and compositions were found especially interesting owing to their distinguished efficiency in energy conversion. Although the advantages of Zintl phases as thermoelectric materials are obvious due to their complex crystal structures, currently decent thermoelectric performance is primarily limited to some long-known systems. In this short review, recent progress on the Zintl-phase-based thermoelectric materials, including some newly developed series, were summarized and discussed. The ideas on the configuration and optimization of such materials were presented. With attempts to better understand the correlation between structures and properties, it is very hopeful that more Zintl thermoelectric systems can be discovered with high performance.
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•Some recent progresses on thermoelectric Zintl phases were summarized.•Materials featuring various novel structure motifs were compared.•Optimization strategies on related thermoelectric properties were discussed.
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