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The strength–ductility trade-off has been a long-standing dilemma in materials science. This has limited the potential of many structural materials, steels in particular. Here we report a way of enhancing the strength of twinning-induced plasticity steel at no ductility trade-off. After applying torsion to cylindrical twinning-induced plasticity steel samples to generate a gradient nanotwinned structure along the radial direction, we find that the yielding strength of the material can be doubled at no reduction in ductility. It is shown that this evasion of strength–ductility trade-off is due to the formation of a gradient hierarchical nanotwinned structure during pre-torsion and subsequent tensile deformation. A series of finite element simulations based on crystal plasticity are performed to understand why the gradient twin structure can cause strengthening and ductility retention, and how sequential torsion and tension lead to the observed hierarchical nanotwinned structure through activation of different twinning systems.

Biofilm infections can induce chronic inflammation and stall the normal orchestrated course of wound-healing cascades. Herein, pH-switchable antimicrobial hydrogel with nanofiber networks for biofilm eradication and rescuing stalled healing in chronic wounds is reported on the basis of the self-assembly of a designed octapeptide (IKFQFHFD) at neutral pH. This hydrogel is biocompatible and exhibits an acidic pH (pathological environment of infected chronic wounds)-switchable broad-spectrum antimicrobial effect via a mechanism involving cell wall and membrane disruption. The antimicrobial activity of hydrogel is derived from its acidic pH-dependent nanofiber network destabilization and activated release of IKFQFHFD, which is antimicrobial only at acidic pH due to the antimicrobial peptide-like molecular structure. In addition, supramolecular nanofiber networks loaded with drugs of cypate (photothermal agent) and proline (procollagen component) are further developed. In vitro experiments show that loaded drugs exhibit acidic pH (pH ∼ 5.5)-responsive release profiles, and synergistic biofilm eradication and subsequent healing cascade activation of cells proliferation are achieved on the basis of the supramolecular nanofiber networks. Remarkably, the nanofiber networks of hydrogel enable in vivo complete healing of MRSA biofilm infected wound in diabetic mice within 20 days, showing great potential as promising chronic wound dressings. The proposed synergistic strategy for eradicating biofilm and activating subsequent healing cascades may offer a powerful modality for the management of clinical chronic wounds.

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Antimicrobial hydrogels are prepared based on the co‐assembly of commercial Fmoc‐phenylalanine and Fmoc‐leucine, which act as the hydrogelator and antimicrobial building block, respectively. This co‐assembled antimicrobial hydrogel is demonstrated to exhibit selective bactericidal activity for gram‐positive bacteria while being biocompatible with normal mammalian cells, showing great potential as an antimicrobial coating for clinical anti‐infective applications.

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Ferroptosis, a novel form of programmed cell death, is characterized by iron-dependent lipid peroxidation and has been shown to be involved in multiple diseases, including cancer. Stimulating ferroptosis in cancer cells may be a potential strategy for cancer therapy. Therefore, ferroptosis-inducing drugs are attracting more attention for cancer treatment. Here, we showed that erianin, a natural product isolated from Dendrobium chrysotoxum Lindl, exerted its anticancer activity by inducing cell death and inhibiting cell migration in lung cancer cells. Subsequently, we demonstrated for the first time that erianin induced ferroptotic cell death in lung cancer cells, which was accompanied by ROS accumulation, lipid peroxidation, and GSH depletion. The ferroptosis inhibitors Fer-1 and Lip-1 but not Z-VAD-FMK, CQ, or necrostatin-1 rescued erianin-induced cell death, indicating that ferroptosis contributed to erianin-induced cell death. Furthermore, we demonstrated that Ca2+/CaM signaling was a critical mediator of erianin-induced ferroptosis and that blockade of this signaling significantly rescued cell death induced by erianin treatment by suppressing ferroptosis. Taken together, our data suggest that the natural product erianin exerts its anticancer effects by inducing Ca2+/CaM-dependent ferroptosis and inhibiting cell migration, and erianin will hopefully serve as a prospective compound for lung cancer treatment.

Carbon‐based quantum dots (CQDs), including spherical carbon dots and graphene quantum dots, are an emerging class of photoluminescent (PL) materials with unique properties. Great progress has been made in the design and fabrication of high‐performance CQDs, however, the challenge of developing solid‐state PL CQDs have aroused great interest among researchers. A clear PL mechanism is the basis for the development of high‐performance solid‐state CQDs for light emission and is also a prerequisite for the realization of multiple practical applications. However, the extremely complex structure of a CQD greatly limits the understanding of the solid‐state PL mechanism of CQDs. So far, a variety of models have been proposed to explain the PL of solid‐state CQDs, but they have not been unified. This review summarizes the current understanding of the solid‐state PL of solid‐state CQDs from the perspective of energy band theory and electronic transitions. In addition, the common strategies for realizing solid‐state PL in CQDs are also summarized. Furthermore, the applications of CQDs in the fields of light‐emitting devices, anti‐counterfeiting, fingerprint detection, etc., are proposed. Finally, a brief outlook is given, highlighting current problems, and directions for development of solid‐state PL of CQDs.