Cisplatin resistance is a major challenge for advanced head and neck cancer (HNC). Understanding the underlying mechanisms and developing effective strategies against cisplatin resistance are highly ...desired in the clinic. However, how tumor stroma modulates HNC growth and chemoresistance is unclear.
We show that cancer-associated fibroblasts (CAFs) are intrinsically resistant to cisplatin and have an active role in regulating HNC cell survival and proliferation by delivering functional miR-196a from CAFs to tumor cells via exosomes. Exosomal miR-196a then binds novel targets, CDKN1B and ING5, to endow HNC cells with cisplatin resistance. Exosome or exosomal miR-196a depletion from CAFs functionally restored HNC cisplatin sensitivity. Importantly, we found that miR-196a packaging into CAF-derived exosomes might be mediated by heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). Moreover, we also found that high levels of plasma exosomal miR-196a are clinically correlated with poor overall survival and chemoresistance.
The present study finds that CAF-derived exosomal miR-196a confers cisplatin resistance in HNC by targeting CDKN1B and ING5, indicating miR-196a may serve as a promising predictor of and potential therapeutic target for cisplatin resistance in HNC.
Nitrogen-doped porous hollow carbon spheres were fabricated via hydrothermal pre-carbonization and pyrolysis carbonization using yeast cell templates. After that, the MnO2 nanowires were deposited by ...the in-situ hydrothermal reaction. By controlling the reaction concentration, various MnO2 nanostructures with different morphologies and electrochemical properties were obtained. The as-prepared sample exhibited an ultrahigh specific capacitance of 255 F g-1 at a current density 1 A g-1 in 1 M Na2SO4 electrolyte. The MnO2/HCS-30 material was used as the positive electrode, and the HCS was used as the negative electrode to assemble the asymmetric supercapacitor. The maximum energy density operating at the 2.0 V voltage window is 41.4 Wh kg−1 at a power density of 500 W kg−1 and still maintains 23.0 Wh kg−1 at a power density of 7901 W kg−1. Moreover, it displayed excellent cycle stability, retained approximately 93.9% of the capacitance after 5000 cycles. This work innovatively combines biomass and energy, provides an environmentally benign strategy and new insights for the preparation of electrode materials.
An asymmetric supercapacitors based on MnO2@Biological cell template synthesized nitrogen-doped porous hollow carbon spherical composites exhibited high energy and power density and an excellent cycle stability. Display omitted
•N-doped porous hollow carbon spheres were synthesized based on yeast templates.•The MnO2 nanowires were anchored by one-step hydrothermal deposition.•The prepared composite material exhibited a unique hollow structure.•As-prepared asymmetric supercapacitors exhibited excellent capacitive behavior.
The distribution of earthquakes at intermediate depths corresponding to pressures <2 GPa in several hot subduction zones (such as Cascadia and southwestern Japan) coincides with the breakdown of ...antigorite to forsterite and talc; thus, this reaction may have triggered these earthquakes. However, previous studies have overlooked the potential significance of this reaction. Here, we performed a series of time-dependent dehydration experiments on antigorite at a pressure of 200 MPa and a temperature range of 500-650°C. The results show that dehydration is controlled by a heterogeneous nucleation and growth mechanism and has an activation energy of 354 ± 24 kJ/mol. The formation of fine-grained forsterite and large talc crystals is consistent with kinetic results indicating Avrami exponents n = ∼1.4-1.1 and ∼2.7, respectively. Fluid production rates at 600 and 650°C are 2.54 × 10-6 and 4.69 × 10-5 mfluid3mrock-3s-1, respectively, which are much faster than those of mantle deformation, causing high fluid pressure in hot subducting mantle but not necessarily embrittlement. We emphasize the role of kinetic mechanisms in controlling the grain sizes of reaction products, which likely determine the mechanical behavior of serpentinized fault zones. Superplasticity or velocity weakening of fine-grained forsterite and velocity weakening of antigorite by water and/or talc may be responsible for earthquake nucleation and propagation in a heterogeneous system, which can be either dehydration products within a serpentinized fault zone or the mixture of antigorite fault and surrounding peridotite in hot subduction zones (<2 GPa).
Abstract
The discord between the insufficient abundance and the excellent electrocatalytic activity of Pt urgently requires its atomic-level engineering for minimal Pt dosage yet maximized ...electrocatalytic performance. Here we report the design of ultrasmall triphenylphosphine-stabilized Pt
6
nanoclusters for electrocatalytic hydrogen oxidation reaction in alkaline solution. Benefiting from the self-optimized ligand effect and atomic-precision structure, the nanocluster electrocatalyst demonstrates a high mass activity, a high stability, and outperforms both Pt single atoms and Pt nanoparticle analogues, uncovering an unexpected size optimization principle for designing Pt electrocatalysts. Moreover, the nanocluster electrocatalyst delivers a high CO-tolerant ability that conventional Pt/C catalyst lacks. Theoretical calculations confirm that the enhanced electrocatalytic performance is attributable to the bifold effects of the triphenylphosphine ligand, which can not only tune the formation of atomically precise platinum nanoclusters, but also shift the
d
-band center of Pt atoms for favorable adsorption kinetics of *H, *OH, and CO.
Polyaniline has been widely used in high-performance pseudocapacitors, due to its low cost, easy synthesis, and high theoretical specific capacitance. However, the poor mechanical properties of ...polyaniline restrict its further development. Compared with polyaniline, functionalized carbon materials have excellent physical and chemical properties, such as porous structures, excellent specific surface area, good conductivity, and accessibility to active sites. However, it should not be neglected that the specific capacity of carbon materials is usually unsatisfactory. There is an effective strategy to combine carbon materials with polyaniline by a hybridization approach to achieve a positive synergistic effect. After that, the energy storage performance of carbon/polyaniline hybridization material has been significantly improved, making it a promising and important electrode material for supercapacitors. To date, significant progress has been made in the synthesis of various carbon/polyaniline binary composite electrode materials. In this review, the corresponding properties and applications of polyaniline and carbon hybrid materials in the energy storage field are briefly reviewed. According to the classification of different types of functionalized carbon materials, this article focuses on the recent progress in carbon/polyaniline hybrid materials, and further analyzes their corresponding properties to provide guidance for the design, synthesis, and component optimization for high-performance supercapacitors.
Spintronic devices based on antiferromagnetic (AFM) materials hold the promise of fast switching speeds and robustness against magnetic fields
. Different device concepts have been predicted
and ...experimentally demonstrated, such as low-temperature AFM tunnel junctions that operate as spin-valves
, or room-temperature AFM memory, for which either thermal heating in combination with magnetic fields
or Néel spin-orbit torque
is used for the information writing process. On the other hand, piezoelectric materials were employed to control magnetism by electric fields in multiferroic heterostructures
, which suppresses Joule heating caused by switching currents and may enable low-energy-consuming electronic devices. Here, we combine the two material classes to explore changes in the resistance of the high-Néel-temperature antiferromagnet MnPt induced by piezoelectric strain. We find two non-volatile resistance states at room temperature and zero electric field that are stable in magnetic fields up to 60 T. Furthermore, the strain-induced resistance switching process is insensitive to magnetic fields. Integration in a tunnel junction can further amplify the electroresistance. The tunnelling anisotropic magnetoresistance reaches ~11.2% at room temperature. Overall, we demonstrate a piezoelectric, strain-controlled AFM memory that is fully operational in strong magnetic fields and has the potential for low-energy and high-density memory applications.
Lipid metabolism that correlates tightly to the glucose metabolic regulation in malignant cells includes hepatocellular carcinoma (HCC) cells. The transcription factor Sterol Regulatory Element ...Binding Protein 1 (SREBP-1), a regulator of fatty acid synthesis, has been shown to pivotally regulate the proliferation and metastasis of HCC cells. However, the intrinsic mechanism by which SREBP-1 regulates the survival of HCC cells remains unclear. In this study, among HCC patients who had dismal responses to Sorafenib, a high SREBP-1 level was found in the tumors and correlated to poor survival. This observation suggested the negative role of SREBP-1 in clinical HCC prognosis. Our mechanistical studies reveal that the inhibition of SREBP-1 via its inhibitor Betulin suppresses cellular glucose metabolism. In addition to the reduced glycolytic activity, a thwarted metastatic potential was observed in HCC cells upon Betulin administration. Moreover, our data show that SREBP-1 inhibition facilitated the antitumor effects of Sorafenib on HCC cells and xenograft tumors.
In this work, the effects of heating on photocatalytic overall water splitting over ZnTi-LDH were investigated. The results showed that the photocatalytic H
2
production rate increased up to 8 times ...when the reaction temperature increased from 150 °C to 250 C, demonstrating the significant influence of temperature on the photocatalytic activity. The UV-vis DRS, photocurrent response, EIS and Mott-Schottky results at different temperatures revealed that the heat can improve the absorption of visible light by narrowing the bandgap, increase the concentration of carriers, and promote the effective separation of photogenerated electrons and holes, thus resulting in the enhancement of photocatalytic performance. In addition,
in situ
FTIR analysis showed that the increase of temperature can accelerate the formation of surface peroxide hydrogen species and bridge hydroxyl groups to enhance the surface photocatalytic oxygen evolution reaction (OER), improving the photocatalytic efficiency.
H
2
O
2
and bridge hydroxyl groups form because of water splitting. This process occurs intensely with the addition of heat, resulting in generation of more intermediates. Meanwhile, the separation of electrons and holes is accelerated by the heat.
Anesthesia may induce neurotoxicity and neurocognitive impairment in young mice. However, the underlying mechanism remains largely to be determined. Meanwhile, autophagy is involved in brain ...development and contributes to neurodegenerative diseases. We, therefore, set out to determine the effects of sevoflurane on autophagy in the hippocampus of young mice and on cognitive function in the mice.
Six day-old mice received 3% sevoflurane, for two hours daily, on postnatal days (P) 6, 7 and 8. We then decapitated the mice and harvested the hippocampus of the young mice at P8. The level of LC3, the ratio of LC3-II to LC3-I, and SQSTM1/p62 level associated with the autophagy in the hippocampus of the mice were assessed by using Western blotting. We used different groups of mice for behavioral testing via the Morris Water Maze from P31 to P37.
The anesthetic sevoflurane increased the level of LC3-II and ratio of LC3-II/LC3-I, decreased the p62 level in the hippocampus of the young mice, and induced cognitive impairment in the mice. 3-Methyladenine, the inhibitor of autophagy, attenuated the activation of autophagy and ameliorated the cognitive impairment induced by sevoflurane in the young mice.
These data showed that sevoflurane anesthesia might induce cognitive impairment in the young mice via activation of autophagy in the hippocampus of the young mice. These findings from the proof of concept studies have established a system and suggest the role of autophagy in anesthesia neurotoxicity and cognitive impairment in the young mice, pending further investigation.
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