Lung tumor segmentation in thoracic CT scans is vital for radiomics analysis and treatment assessment, but is hindered by heterogeneous tumor morphology, ambiguous boundaries, and inaccuracy and labor-intensiveness of manual segmentation. Existing methods, including traditional machine learning and deep learning methods, often suffer from over-/under-segmentation or poor robustness. In this study, we propose an improved Segment Anything Model (called Tumor-SAM) for semi-automatic lung tumor segmentation, integrating U-Net for multi-scale feature extraction and a novel ellipse prompt. Tumor-SAM first detects lung ROI to reduce interference from the surrounding tissue. Then, we design an ellipse prompt defined by center, axes, and rotation that captures tumor shape/location better than points, boxes, or circles. The architecture of Tumor-SAM includes a U-Net-based image encoder (replacing ViT), prompt encoder with positional encoding, multi-head attention fusion, and mask decoder. Our method achieved an average Dice index of 0.84±0.13 and an average Hausdorff distance of 7.25±6.24 mm on 164 testing scans, demonstrating good lung tumor segmentation accuracy.
Here, we demonstrate a highly efficient mode conversion structure based on a bilayer inverse taper at 1064 nm on a thin-film lithium niobate substrate. Simulations considering both lensed fiber and UHNA fiber coupling to the inverse taper were conducted and analyzed, showing a loss of less than 0.5 dB per facet with optimized taper parameters. The simulated device validates the potential of bilayer inverse tapers as a scalable and efficient coupling solution for high-performance photonic devices at 1064 nm.
Blue phase liquid crystals (BPLCs), featuring double-helix cholesteric structures, are considered for next-generation displays and optical components. However, conventional BPLCs are limited to a narrow 0.5-3 degrees C temperature range, hindering their wide application and requiring polymer networks for stabilization. This article investigates the effects of various cross-linker concentrations, polymerization conditions, nanofibre diameters, and thicknesses on the temperature domain and electro-optical properties of polymer-stabilized BPLCs (PS-BPLCs). Doping with nanofibre film significantly improved these properties, as well as durability and stability. This approach presents a promising prospect for BPLC-based devices with wide temperature range and fast response, useful in various applications.
Thermodynamic analysis of phase formation processes in amorphous alloys of the Fe-B system has been carried out. A new expression is proposed to describe the concentration dependence of the relative Gibbs free energy for the initial amorphous phase, which takes into account the dependence of entropy on the volume change during alloy formation. The constructed concentration dependences of the relative integrated Gibbs free energy for the original amorphous phase do not have a specific S-shaped form, which indicates the impossibility of phase separation within the amorphous state for these binary alloys.
A new series of 1,3,4-oxadiazole derivatives featuring a hockey-stick-shaped molecular architecture, composed of five interconnected phenyl rings linked via imine and ester functionalities, was successfully synthesised. The target compounds, designated as 4-(((4-(5-(4-methoxyphenyl)-1,3,4-oxadiazol-2-yl)phenyl)imino)methyl)phenyl-4-((4-alkoxyben-zylidene)amino)benzoate [Dn], were thoroughly characterised by Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (H-1 NMR), mass spectrometric analysis (GC-MS), and elemental analysis. The liquid crystalline properties of the series were investigated using polarised optical microscopy (POM) and differential scanning calorimetry (DSC). The homologues [D6-D11] exhibited a liquid crystalline behaviour, displaying both smectic A (SmA) and smectic C (SmC) mesophases across a broad temperature range, beginning at approximately 140 degrees C. A comparative analysis indicated that the insertion of the (-N=CH-Ph) moiety into the molecular core influences the mesomorphic behaviour of the synthesised derivatives relative to previously reported compounds.
