Helium accumulation in structural ceramics used in nuclear, fusion, and aerospace systems causes swelling, cracking, and early failure, yet controlling this damage has remained elusive. Here, we introduce defect landscape engineering, the deliberate creation of vacancy clusters prior to helium exposure, as a general strategy to suppress helium-induced degradation. Using α-SiC as a model, we combine advanced microscopy, strain mapping, helium depth profiling, positron annihilation spectroscopy, and atomistic simulations to demonstrate that tailored pre-damage transforms helium defect evolution. Instead of forming extended platelets and nanocracks, helium is trapped in stable, uniformly dispersed nanobubbles. Simulations reveal that small vacancy clusters act as dual-function sinks for irradiation-induced interstitials and preferential traps for helium, fundamentally altering the dynamics of cascade recombination. This mechanism is composition-independent and scalable, offering a new design principle for radiation-tolerant ceramics across carbides, nitrides, and oxides. By viewing defect control as a tunable parameter instead of a fixed material property, this work outlines a possible design route toward enhanced radiation tolerance in ceramics used in extreme environments.

CDK2 has emerged as a pivotal target in cancer chemotherapy. To develop a novel CDK2 inhibitor scaffold, multiple rational, structure-based design strategies were applied to known potent CDK2 inhibitors. Through retrosynthetic planning, chemical synthesis, and characterisation, compounds 2–8 were generated. Initial in vitro screening using the NCI-60 cancer cell line panel, followed by accurate cytotoxicity (GI₅₀) measurements, shortlisted compounds 5, 8b, and 8d as promising candidates. These compounds exhibited GI₅₀ values as low as 0.6 μM and demonstrated favourable safety profiles, with selectivity indices reaching up to 7.98. The top two active compounds, 5 and 8b, were further evaluated against the most sensitive cell line, MDA-MB-468 (breast cancer), at their respective GI₅₀ concentrations. Flow cytometric cell cycle analysis revealed 82% and 78% G1 phase arrest for compounds 5 and 8b, respectively, suggesting an effective CDK2/cyclin E targeting mechanism. Furthermore, annexin V-FITC apoptosis assays showed robust pro-apoptotic effects, with total apoptosis induction elevated 34.5-fold and 32.4-fold over the negative control for compounds 5 and 8b, respectively. Subsequent CDK2/cyclin E1 enzymatic inhibition assays confirmed the potency of these compounds, with IC₅₀ values of 3.92 nM for 5 and 0.77 nM for 8b, compared to 1.94 nM for the reference inhibitor roscovitine. Notably, the novel lead compound 8b exhibited approximately 2.5-fold greater potency than roscovitine. Molecular docking studies further supported the experimental findings and provided structural insights for future optimisation of this promising CDK2 inhibitor scaffold.

Topological rainbow trapping (TRT) arises from the interplay between topological states and frequency-dependent slow-wave effects. Waves first slow down, then become spatially separated by frequency and are ultimately trapped at distinct locations. TRT designs have been primarily explored in the context of photonic crystals and subsequently extended to acoustic and elastic systems. This emerging TRT concept enables robust, frequency-selective localization beyond conventional rainbow trapping, supporting compact, multi-wavelength, topologically protected platforms for extreme wave manipulation. In this Review, we elucidate the fundamental principles of TRT, emphasizing the physical mechanisms that create near-zero group velocity points with robust frequency-dependent localization. We highlight three key TRT mechanisms: graded index profiles, which gradually vary material parameters to reshape dispersion and induce slow-wave effects; higher-order topological corner modes, which exploit localized corner states for robust frequency-specific wave confinement; and synthetic dimensions, which expand the parameter space of the system to engineer stable interface states at distinct frequencies. Furthermore, we address key challenges in TRT, such as energy dissipation and tunability, while highlighting its broad range of potential applications. Finally, we discuss emerging research directions for TRT. 

Rainbow trapping is a wave localization phenomenon in which different frequencies are spatially separated and confined by engineering dispersion through structural gradients. Initially demonstrated in tapered metamaterial systems, this concept has since been extended to plasmonic, photonic, acoustic, and elastic platforms, where graded-index profiles, chirped periodicities, and tapered geometries are used to control the group velocity and localize wave components at distinct spatial positions. These implementations enable highresolution spectral manipulation and form the foundation for broadband wave control. More recently, topological rainbow trapping has emerged as a robust alternative, leveraging topologically protected states to achieve disorder-immune frequency localization. This approach offers enhanced resilience to fabrication imperfections and opens new possibilities for scalable, integrated wave-based devices. In this review, we examine the physical mechanisms, system-specific implementations, and recent advances in both conventional and topological rainbow trapping. We also highlight promising applications ranging from optical communication and wavelength multiplexing to acoustic wave manipulation and vibrational energy harvesting and discuss key challenges and future directions in this rapidly evolving field.