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Eutectic high‐entropy alloys (EHEAs), with good castability, compositional homogeneity, and outstanding properties, are becoming hotpots in materials field. It is worth noting that most reported EHEAs are based on expensive and high density of metal elements, such as Hf, Zr, Ta, Nb, W, and Pd, which increase the overall cost and quality. Herein, by selecting the cost‐effective and low‐density of Ti and Si as eutectic forming elements, a novel CoCrFeNi2(TiSi)0.7 EHEA with face‐centered‐cubic (FCC) + M16Ti6Si7‐type silicide is designed and prepared. The evolution of microstructure and mechanical properties is investigated under different annealing conditions. The CoCrFeNi2(TiSi)0.7 EHEA shows excellent high‐temperature mechanical properties. At 800 °C, the as‐cast and annealed samples do not fracture under a compressive strain exceeding 50%. In particular, a long period of high‐temperature annealing dramatically increases the high‐temperature yield strength from 510 to 703 MPa, which exceeds that of most reported EHEAs and some refractory high‐entropy alloys. [ABSTRACT FROM AUTHOR]

Adopting the idea of thermal modification of conventional Si-containing eutectic alloys, this study performed heating of the brittle CoFeNi2(Ti3Si5)0.16 eutectic high-entropy alloy under various annealing conditions to attempt the fragmentation and spheroidization of eutectic microstructure and improve fracture plasticity. Results reveal that the as-cast alloy exhibited fine eutectic microstructures with lamellar + network morphologies, consisting of face-centered cubic (FCC) and M16Ti6Si7-type silicide. After annealing at 1100°C × 120 h, the lamellar + network eutectic morphologies were effectively fragmented and spheroidized into granular + irregular morphologies. The resulting alloy featured excellent mechanical properties with an ultimate compressive strength (UCS) of 1980 ± 50 MPa, fracture plasticity of ∼16.6% ± 1%, and hardness of ∼448 ±15 HV. Compared with the as-cast specimen, the fracture plasticity of the specimen annealed for 120 h increased by 12.7 times, with no UCS reduction. With a further increase in the annealing time, the hard M16Ti6Si7-type silicide was seriously coarsened, deteriorating the alloy's room-temperature mechanical properties but improving its high-temperature ones. [ABSTRACT FROM AUTHOR]

The presence of blood–brain barrier (BBB) that limits effective penetration of therapeutics is the main reason for poor outcomes of glioblastoma (GBM) treatment. Ultrasound (US) combined with microbubbles (MBs) can precisely disrupt the tight junctions of brain endothelial cells, thus creating "acoustic pores" and non‐invasive opening the BBB. Here, chitosan oligosaccharide (COS) is conjugated with a sonosensitizer protoporphyrin IX (PpIX) and an immune‐enhancing adjuvant Poly(I:C) via electrostatic adsorption, and cross‐linked with a tumor‐targeting molecule hyaluronic acid (HA) affording nanosonosensitizers HA‐Poly(I:C)/COS‐PpIX (abbreviated as "HP/CP" NSs). HP/CP NSs can target and penetrate GBMs, and trigger reactive oxygen species production upon US, simultaneously causing mitochondrial dysfunction and DNA damage. Tumor‐associated antigens released by sonodynamic therapy‐induced immunogenic cell death and loaded Poly(I:C) form an in situ vaccine together to potentiate antitumor immune responses. In orthotopic GBM mice models, the HP/CP+US treatments prolong mice survival, enhance cytotoxic T‐lymphocytes infiltration, and activate peripheral immune circulation. Besides, HP/CP NSs possess favorable biosafety profiles. Collectively, this study sheds light on the application of HP/CP NSs for synergistic sono‐immunotherapy of GBMs after non‐invasive opening of the BBB. [ABSTRACT FROM AUTHOR]