Glass ceramics were synthetized using Cr2O3 and CaF2 as additives, and their structure, crystal growth behavior, and physicochemical properties were investigated. The results showed that an excessive ...amount of Cr2O3 leads to the formation of a spinel structure in the glass matrix and an increase in the number of Q3Si units. The addition of CaF2 promoted the decomposition of Q2Si into Q1Si and Q3Si. Compared with the sample with Cr2O3 alone, the addition of CaF2 helped reduce the glass transition and crystallization temperatures, forming sharper crystallization peaks. Although CaF2 increased the activation energy of crystallization, it increased the degree of crystallinity and Avrami parameter (2.019). In terms of the microstructure, the sample added with CaF2 formed a snowflake-like structure with a spinel core. An excessive amount of spinel reduced the strength of the samples. The samples (1.5Cr2O3-3.5CaF2) exhibited a maximum flexural strength of 149.85 MPa and a good chemical resistance.
Human carcinomas frequently exhibit significant stromal reactions such as the so-called "desmoplastic stroma" or "reactive stroma", which is characterised by the existence of large numbers of stromal ...cells and extracellular matrix proteins. Carcinoma-associated fibroblasts (CAFs), which are rich in activated fibroblast populations exemplified by myofibroblasts, are among the predominant cell types present within the tumour-associated stroma. Increased numbers of stromal myofibroblasts are often associated with high-grade malignancies with poor prognoses in humans. CAF myofibroblasts possess abilities to promote primary tumour development, growth and progression by stimulating the processes of neoangiogenesis as well as tumour cell proliferation, survival, migration and invasion. Moreover, it has been demonstrated that CAFs serve as a niche supporting the metastatic colonisation of disseminated carcinoma cells in distant organs. Their contribution to primary and secondary malignancies makes these fibroblasts a potential therapeutic target and they also appear to be relevant to the development of drug resistance and tumour recurrence. This review summarises our current knowledge of tumour-promoting CAFs and discusses the therapeutic feasibility of targeting these cells as well as disrupting heterotypic interactions with other cell types in tumours that may improve the efficacy of current anti-tumour therapies.
The calcium fluoride (CaF2) nanoparticles having an ultrawide bandgap of 12.1 eV and a good dielectric constant of 10 are prepared and introduced into the polyimide (PI) matrix, yielding an excellent ...high-temperature energy storage performance.
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•Dielectric CaF2 nanoparticles with a wide bandgap were prepared.•CaF2 nanofillers are applied for the first time in polymer dielectric composites.•PI/CaF2 processes high Ue of 2.68 J cm−3 and Eb of 455.4 MV m−1 at 150 ℃.•CaF2 nanofillers induce deep traps to inhibit conduction loss at high temperatures.
In advanced electronics and electrical power systems, polymer dielectric capacitors are favored for their high power density and great reliability. However, the low energy density at high temperatures constrains their use in emerging applications. To address this vital issue, herein, a novel calcium fluoride (CaF2) nanoparticle with a wide bandgap (∼12.1 eV) and moderate permittivity (∼10.0) is prepared by a simple direct precipitation method and then introduced into the polyimide (PI) matrix. The incorporation of the CaF2 nanoparticles increases the permittivity and reduces conduction loss simultaneously. Consequently, at 150 ℃, the PI film with 3 vol% CaF2 exhibits enhanced discharged energy density and breakdown field of 2.68 J cm−3 and 455.4 MV m−1, respectively. Besides, the composite shows a higher power density of 0.36 MW cm−3 and a faster discharge speed of 2.09 μs at 150 ℃ than that 2.93 μs of biaxially oriented polypropylene (BOPP) measured at 85 ℃. Notably, CaF2 nanofiller, as a deep trap, captures injected charges and alleviates the local electric distortion, as revealed by finite element simulation and thermally stimulated discharge current (TSDC) measurement. This work proposes a novel fluoride nanofiller to rationalize the energy storage improvement of high-temperature composites with potential wide application.
Previous work about CAF through a T-pipe reported that CAF stability could not be maintained after passing the intersection. The current CFD study was expected to propose a strategy to recover the ...stability of CAF in a horizontal T-pipe without interrupting the flow process. A recirculation zone was detected in the area near the junction. Additional water with a certain design of insertion and water velocity is introduced at the intersection to support the recovery of CAF by suppressing fouling. This numerical work covered both qualitative evaluation of CAF consistency along the T-pipe and quantitative evaluation to analyze the attainable energy savings of the proposed strategy. From some candidates for water insertion geometries and velocities of additional water, the ducting insertion with a water velocity of 2 m/s showed a consistent CAF structure starting at about 200 mm from the intersection point to the final downstream exits. This proposed design was estimated to reduce pressure drop more than 98% compared to transportation without lubrication and 4% higher than design without additional water injection. The power reduction factor was computed at a value greater than 1 (30.3), indicating that the proposed system was energetically more advantageous than the single-phase oil system.
Radio-photoluminescence (RPL) phenomenon was observed in CaF2 transparent and opaque ceramics by X-ray irradiation. The RPL appeared as a formation of photoluminescence (PL) emission bands located ...around 660 and 720 nm caused by F2+ and (F2+)A centers, respectively. The RPL signal can be deleted by heating, and reusability was observed over ten experimental cycles. The fading of the RPL signal was confirmed to be ~4% in 10 days. The detectable RPL response of CaF2 transparent ceramics was as low as 1 mGy, and the dynamic ranges were confirmed over 1–10000 mGy with linear response.
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•Radio-photoluminescence (RPL) phenomenon was observed in CaF2 transparent and opaque ceramics by X-ray irradiation.•The RPL signal can be deleted by heating, and reusability was observed over ten experimental cycles.•The sensitivity of CaF2 transparent ceramics as RPL dosimeters was confirmed 1 mGy.
Fibroblasts display extensive transcriptional heterogeneity, yet functional annotation and characterization of their heterocellular relationships remains incomplete. Using mass cytometry, we chart ...the stromal composition of 18 murine tissues and 5 spontaneous tumor models, with an emphasis on mesenchymal phenotypes. This analysis reveals extensive stromal heterogeneity across tissues and tumors, and identifies coordinated relationships between mesenchymal and immune cell subsets in pancreatic ductal adenocarcinoma. Expression of CD105 demarks two stable and functionally distinct pancreatic fibroblast lineages, which are also identified in murine and human healthy tissues and tumors. Whereas CD105-positive pancreatic fibroblasts are permissive for tumor growth in vivo, CD105-negative fibroblasts are highly tumor suppressive. This restrictive effect is entirely dependent on functional adaptive immunity. Collectively, these results reveal two functionally distinct pancreatic fibroblast lineages and highlight the importance of mesenchymal and immune cell interactions in restricting tumor growth.
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•Mass cytometry analysis of mesenchymal stroma in murine normal and tumor tissue•Mesenchymal heterogeneity is a feature of human and murine tissues and tumors•CD105 expression distinguishes two pancreatic fibroblast lineages•CD105neg pancreatic fibroblasts support anti-tumor immunity to control tumor growth
Hutton et al. use mass cytometry to chart stromal cells and describe mesenchymal states and lineages in pancreatic ductal adenocarcinoma. CD105 (Eng) expression distinguishes two pancreatic fibroblast lineages with distinct functions. CD105pos fibroblasts are tumor permissive, whereas CD105neg fibroblasts suppress tumor growth in a manner dependent on adaptive immunity.
Ytterbium segregation (brighter zone) at a grain boundary in the CaF
2 lattice is shown here using the HAADF mode of a STEM. Each spot on the image corresponds to a 4
nm deep column of atoms. This is ...one type of grain boundary defects in the ytterbium doped calcium fluoride transparent ceramic.
The origin of light scattering defects was studied in transparent 6
at% Yb:CaF
2 ceramics. Samples were synthesized by a soft chemistry route followed by sintering and hot pressing which leads to highly transparent ceramics with low scattering losses (0.016
cm
−1 at 1200
nm). Light scattering defects were studied using scanning transmission electron microscopy (STEM) and high angle annular dark field-STEM (HAADF-STEM) techniques. Energy dispersive X-ray spectroscopy showed a 50% increase in Yb
3+ concentration at grain boundaries. A 3–5
nm thick oxygen rich phase was detected at some grain boundaries by both HAADF-STEM and EDS. The origin of the oxygenized grain boundaries was traced to a 2–15
nm thick oxygenized shell present on the starting powders. Analysis of high resolution HAADF-STEM images revealed that Yb
3+ substitutes into the fluorite lattice as clusters rather than individual ions, but the types of clusters could not be identified by this imaging technique.
Cancer-associated fibroblasts (CAFs), a stromal cell population with cell-of-origin, phenotypic and functional heterogeneity, are the most essential components of the tumor microenvironment (TME). ...Through multiple pathways, activated CAFs can promote tumor growth, angiogenesis, invasion and metastasis, along with extracellular matrix (ECM) remodeling and even chemoresistance. Numerous previous studies have confirmed the critical role of the interaction between CAFs and tumor cells in tumorigenesis and development. However, recently, the mutual effects of CAFs and the tumor immune microenvironment (TIME) have been identified as another key factor in promoting tumor progression. The TIME mainly consists of distinct immune cell populations in tumor islets and is highly associated with the antitumor immunological state in the TME. CAFs interact with tumor-infiltrating immune cells as well as other immune components within the TIME via the secretion of various cytokines, growth factors, chemokines, exosomes and other effector molecules, consequently shaping an immunosuppressive TME that enables cancer cells to evade surveillance of the immune system. In-depth studies of CAFs and immune microenvironment interactions, particularly the complicated mechanisms connecting CAFs with immune cells, might provide novel strategies for subsequent targeted immunotherapies. Herein, we shed light on recent advances regarding the direct and indirect crosstalk between CAFs and infiltrating immune cells and further summarize the possible immunoinhibitory mechanisms induced by CAFs in the TME. In addition, we present current related CAF-targeting immunotherapies and briefly describe some future perspectives on CAF research in the end.
The microenvironment encompasses all components of a tumor other than the cancer cells themselves. It is highly heterogenous, comprising a cellular component that includes immune cells, fibroblasts, ...adipocytes, and endothelial cells, and a non-cellular component, which is a meshwork of polymeric proteins and accessory molecules, termed the extracellular matrix (ECM). The ECM provides both a biochemical and biomechanical context within which cancer cells exist. Cancer progression is dependent on the ability of cancer cells to traverse the ECM barrier, access the circulation and establish distal metastases. Communication between cancer cells and the microenvironment is therefore an important aspect of tumor progression. Significant progress has been made in identifying the molecular mechanisms that enable cancer cells to subvert the immune component of the microenvironment to facilitate tumor growth and spread. While much less is known about how the tumor cells adapt to changes in the ECM nor indeed how they influence ECM structure and composition, the importance of the ECM to cancer progression is now well established. Plasticity refers to the ability of cancer cells to modify their physiological characteristics, permitting them to survive hostile microenvironments and resist therapy. Examples include the acquisition of stemness characteristics and the epithelial-mesenchymal and mesenchymal-epithelial transitions. There is emerging evidence that the biochemical and biomechanical properties of the ECM influence cancer cell plasticity and vice versa. Outstanding challenges for the field remain the identification of the cellular mechanisms by which cancer cells establish tumor-promoting ECM characteristics and delineating the key molecular mechanisms underlying ECM-induced cancer cell plasticity. Here we summarize the current state of understanding about the relationships between cancer cells and the main stromal cell types of the microenvironment that determine ECM characteristics, and the key molecular pathways that govern this three-way interaction to regulate cancer cell plasticity. We postulate that a comprehensive understanding of this dynamic system will be required to fully exploit opportunities for targeting the ECM regulators of cancer cell plasticity.
The effect and mechanism of ultrasound and CaF2 on vanadium leaching from vanadium-bearing shale were investigated systematically. In consideration of the enhancement for vanadium recovery, the ...combination of ultrasound and CaF2 (66.28%) exerts more evident effects than ultrasound (26.97%) and CaF2 (60.35%) alone, demonstrating the synergetic effect of ultrasound and CaF2. Kinetic analysis manifests that the product layer diffusion controls vanadium leaching in ultrasound system without CaF2, however product layer diffusion and interfacial reaction is the rate-controlling step for vanadium leaching in other three leaching systems. The combination of ultrasound and CaF2 notably decreases the activation energy (Ea) from 62.03 to 27.61 kJ/mol, nevertheless individual CaF2 only reduces the Ea to 50.70 kJ/mol. X-ray diffraction and fourier transform infrared spectrometer analyses show that the decomposition degree of the vanadium-bearing mica structure is the most significant in ultrasound and CaF2 system, proving the highest release degree of vanadium. Specific surface area and pore distribution combined with scanning electron microscope analyses reveal that the action of ultrasound and CaF2 would provide higher specific surface area, more abundant pores structure and cracks for the particles, which further prompts the rapid diffusion of H+, F− and HF, and achieves the conspicuous improvement of vanadium leaching recovery.
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