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Extreme light confinement observed in periodic photonic structures, such as the vortex singularities in momentum (k) space, has been associated with their topological nature. Consequently, by exploiting and tuning their topological properties, optical metasurfaces have been demonstrated as an attractive platform for active photonics. However, given the fact that most active media under external excitations can only provide limited refractive index change, the potential advancements offered by the topological character of active metasurfaces have remained mostly unexplored. Zinc oxide (ZnO), which has recently exhibited optically-induced extraordinarily large permittivity modulations at visible and near-infrared frequencies, is an excellent active material for dynamic metasurfaces exhibiting strong tuning. This work demonstrates that a hybrid metasurface consisting of an array of ZnO nanodisks on a silver backplane displays broadly tunable topological properties. In particular, by performing k-space scattering simulations using measured pump-fluence-dependent material properties of ZnO, we study in detail the light reflection from the hybrid metasurface. Our results validate that the large k-space topology tuning of the metasurface can result in enormously strong polarization manipulation of near-infrared light in the vicinity of the topological features. The observed polarization switching effect is highly sensitive to the polarization and wavelength of an incident wave, owing to the symmetry and dispersion characteristics of the proposed system. Our study indicates that leveraging a combination of the extraordinary material properties and the k-space topology, hybrid metasurfaces based on ZnO may open new avenues for creating all-optical switchable metadevices.

Spoof plasmonics, which can enable strong terahertz (THz) radiation–matter interactions, hold great promise for the advancement of THz science and technology. However, THz spoof plasmonic devices based on micro-structured metals are in general limited by lithography-based fabrication processes as well as metals' mechanical, chemical, and thermal stability, which hinders their applications in, for instance, flexible and wearable THz imaging and communications, molecular sensing, etc. Possessing high electrical conductivity and outstanding mechanical robustness, graphene-assembled films (GAFs) promise many benefits for electronics as an alternative to metals. Here, by studying the resonance-enhanced transmission properties of subwavelength GAF hole arrays, we demonstrate a GAF metasurface as a transformative platform for flexible THz spoof plasmonics. Based on a laser direct writing (LDW) patterning technique, the proposed micro-engineered GAF is expected to pave the way toward large-area, durable, and inexpensive THz metadevices with superior flexibility. [ABSTRACT FROM AUTHOR]

This article discusses the use of radiomics, a method that involves extracting imaging features from radiologic images, to predict lymph node metastasis (LNM) in colorectal cancer (CRC) patients. The study found that radiomics analysis using 2-[18F]FDG PET-based imaging was more effective in predicting LNM compared to traditional CT and PET reports. The study also highlighted the need for standardization in radiomics workflow and the development of automated segmentation tools. While promising, further research and validation in larger clinical trials are needed before radiomics can be integrated into routine clinical practice. [Extracted from the article]

The highly strained, phenylene‐derived organic cages are typically regarded as very rigid entities, yet their deformation potential and supramolecular properties remain underexplored. Herein, we report a pliable conjugated phenylene nanocage by synergistically merging rigid and flexible building blocks. The anisotropic cage molecule contains branched phenylene chains capped by a calix[6]arene moiety, the delicate conformational changes of which endow the cage with a remarkably deformable cavity. When complexing with fullerene guests, the cage showcases excellent guest‐adaptivity, with its cavity volume capable of swelling by as much as 85 %. [ABSTRACT FROM AUTHOR]

The crystalline Fe–C alloy had been the focal point of research in the traditional metallurgical steel industry. However, its corresponding amorphous alloy system had received little attention, with a lack of consensus on the microstructural evolution. Three types of Fe–C unbalanced composite films with different carbon content were fabricated using the magnetron sputtering method. The results indicated that as the carbon content increased, carbon existed in the form of supersaturated solid solution atoms in crystalline Fe, an amorphous Fe–C structure and Fe3C, respectively. The resistivity of the films in these three carbon types gradually increased from 1.37 × 10−4 ohm/cm to 4.53 × 10−2 ohm/cm and then to 5.43 × 10−2 ohm/cm. Simultaneously, the transmittance gradually increased from 0% to 28% and then to 51%. Upon annealing at 400°C, with the crystallisation of Fe in the low-carbon film, unbalanced carbon atoms were pushed out of the lattice and precipitated as Fe3C. After annealing at 650°C, the Fe3C in the high-carbon film decomposed into Fe and C. The as-prepared medium-carbon film displayed commendable corrosion resistance. These findings provided valuable insights for the design and performance development of new materials. [ABSTRACT FROM AUTHOR]