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.
A pair of diastereoisomers was synthesized from enantiopure epichlorohydrin and isosorbide, with their helical twisting power primarily governed by the isosorbide moiety. These compounds were employed as chiral dopants to prepare thermochromic cholesteric liquid crystal (CLC) mixtures. Patterned CLC polymer network (CLCN) films were then produced through regionally controlled photopolymerization temperatures. By utilizing the angle-dependent structural colors, distinct patterns were realized in a composite film constructed from two such patterned CLCN layers. Furthermore, colorful CLCN patterns were also fabricated via inkjet printing. These CLCN patterns demonstrate significant potential for use in decoration and anti-counterfeiting applications.
Thin sensor films for an optical gas detector were fabricated by chemical deposition of polyaniline onto transparent glass plates coated with a layer of tin oxide. It was found that gas-stimulated changes in their optical absorption spectra under the action of ammonia occur much faster than for films obtained by electrochemical deposition, and within 1 min account for 50%-70% of all changes. Ways to improve the process of restoring the properties of a polymer gas-sensitive layer by heating the control zone using a photoconductive semiconductor layer under its local illumination are proposed.
Polymerizable alkyl chain-derived naphthalene-substituted at the terminal of unsymmetric bent-shaped organic molecules were synthesized and characterized for their mesomeric property. The chemical structures and mesomeric properties were confirmed by spectroscopic techniques, including FTIR, NMR, and microelemental analysis, POM, and DSC. Of the three compounds, two compounds exhibited smectic mesomarphism and the remaining one did not. The mesophase type is confirmed by X-ray diffraction studies of the liquid-crystal state.
The development of high-performance polymer electrolytes remains one of the most critical strategies for improving dye-sensitized solar cell (DSSC) efficiency and stability. This study reports the synthesis, characterization, and application of manganese hydroxide chloride (Mn-2(OH)(3)Cl) as a novel inorganic filler in poly(vinylidene fluoride) (PVDF)-based electrolyte films for DSSCs. Incorporation of Mn-2(OH)(3)Cl into PVDF matrices was shown to significantly improve ionic conductivity by decreasing of crystallinity, and the overall photovoltaic conversion efficiency of DSSCs. The optimal composition (15 wt% Mn-2(OH)(3)Cl) led to a remarkable power conversion efficiency of 6.93%, surpassing most previously reported polymer-based DSSC electrolytes.
A broad-focal-range liquid crystal (LC) lens array enabled by partitioned electric field modulation is proposed, featuring a simple design and low operating voltage. By combining zonal electrodes and a central electrode, the structure improves electric-field regulation in both the edge and central regions, enabling a smooth refractive-index distribution, effective focusing, and a wide focal tuning range. Simulation results show that, at 2 Vrms on the central electrode and 7.9 Vrms on the pixel electrodes, the lens achieves a near-ideal gradient refractive-index profile at a 500 mu m aperture, with a minimum focal length of 1.601 mm. In addition, the phase distribution closely matches the ideal parabolic profile, and the centre-to-edge phase difference reaches approximately 71 pi, indicating strong phase-modulation capability, low spherical aberration, and good imaging potential. Therefore, the proposed structure shows potential for applications in 2D/3D switchable displays.
Intermolecular interactions in TiO2 (anatase) nanopowder and benzophenone (BP) composite were investigated using temperature-dependent FTIR spectroscopy. BP molecules form hydrogen bonds with the TiO2 surface active centers (Ti-O-H and Ti-O-Ti) via phenyl ring pi-electron systems and C-H groups, pi & mldr;H-O-Ti and C-H & mldr;O(-H/-Ti). These interactions induce blue shifts, half-width changes and intensity redistribution of the phenyl stretching nu(C-C(=O)) and bending gamma(C-C-C), gamma(C-C-H) modes, while C = O vibrations remain unaffected. Significant cooling reduces the fraction of surface-bound BP molecules, shifting the balance toward bulk crystalline phase formation.
Chromonic liquid crystals exhibit rich twisted configurations under cylindrical confinement, a challenging scenario for the classical Oseen-Frank theory due to its inherent energy unboundedness paradox in high-curvature settings. To overcome this limitation, we incorporate the quartic twist theory (proposed by Paparini and Virga) into the modelling of a nematic system confined between coaxial cylinders, constructing a more self-consistent continuum model. Under cylindrical symmetry, the equilibrium equation and boundary conditions of the director are derived and solved numerically. The quartic theory effectively resolves the classical energy paradox, demonstrating that axial and azimuthal anchoring conditions drive the twist angle towards 0 degrees and 90 degrees, respectively. This work establishes a reliable theoretical framework for analysing such confined systems and offers crucial insights for future experimental characterisation of anchoring strength and elastic properties.
Sodium sulfate's crystallization kinetics is crucial for industrial processes, but its non-isothermal nucleation-growth mechanism research has limits. This study combines the moment transformation method with experiments, establishing a kinetic model. It reveals a non-linear relationship and factor impacts. The ASL model fits better, with a 10% deviation. The research aids understanding and industrial optimization.
A new mercury-based mixed-anion chalcogenide-halide Hg3S2Br2 (1) was reported. It features a three-dimensional (3D) cationic framework. Density functional theory (DFT) calculations confirm one is a direct-bandgap semiconductor, with the conduction-band minimum (CBM) and valence-band maximum both located at the Gamma point. The computed electronic bandgap is 2.82 eV, in excellent agreement with the 2.71 eV extracted from UV-Vis diffuse reflectance spectroscopy (DRS). Solid-state photoluminescence (PL) measurements show a green emission centered at 496 nm. The CIE 1931 chromaticity coordinates are (0.0608, 0.3811). Thermogravimetric analysis (TGA) indicated that it exhibits thermal stability up to 150 degrees C.
This study investigates the influence of two calamitic liquid crystals exhibiting distinct mesophase structures (nematic LC1 and chiral smectic C* LC2) as functional additives in a commercial iodide/triiodide electrolyte for dye-sensitized solar cells (DSSCs). Rather than targeting state-of-the-art efficiencies, the objective is to evaluate relative performance variations induced by mesophase-dependent electrolyte modulation under identical fabrication conditions. Concentration dependent photovoltaic measurements reveal systematic performance changes associated with LC incorporation. The results suggest a possible structure performance correlation related to liquid crystal molecular ordering within the electrolyte medium.
A series of novel sexiphenyl liquid crystals featuring terminal pentyl chains and lateral alkyl/fluoro substituents were synthesised via a palladium-catalysed route using novel 2,4-dialkylphenyl boronic esters. Compounds exhibited stable nematic mesophases, with lateral substitution reducing clearing points by 300-380 degrees C versus unsubstituted sexiphenyl - with methylated compounds showing supercooling to near-ambient temperatures. Photophysical studies revealed UV-range fluorescence with quantum yields up to 94%, modulated by substituent sterics/electronics. These materials demonstrate exceptional potential for low-temperature nematic applications requiring tunable optoelectronic properties.
In the present study, a novel series of diazo derivatives of vinyl esters (B1-B12) were synthesized and characterized to investigate their liquid crystalline properties. The synthesized compounds were analyzed using spectral techniques (FT-IR, and 1H-NMR), thermal analysis (DSC), and phase identification through optical polarizing microscopy. This study also confirmed that molecular length has a positive effect on liquid crystal behavior by comparative study with reported work. These derivatives are intriguing candidates for improved functional materials in optoelectronic and display applications due to their thermotropic liquid crystalline behavior.
This report describes the effects of the magnetic field on the formation of hydrogel in aqueous solutions of rigid-chain polymers from an S-phase, in which the polymer chains form closely packed individual globules (S-clusters), into the N-phase, in which the aggregates (N-clusters) formed by parallel segments of different chains. The application of the magnetic field results in the appearance of two types of mechanical stresses is associated with deforms S-clusters and rotation of S-cluster as a whole. The possibility of control of phase transition S-N using magnetic field could have practical applications, as hydrogels are used in the pharmaceutical industry.
A new substituted piperidinium picrate, [4-NO2Bz-4-MePid][PIC], was synthesized from 4-methylpiperidine, 4-nitrobenzyl bromide, and picric acid (PA). Single-crystal XRD showed it belongs to triclinic system (space group P-1), and structural characterization was performed via Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflection spectroscopy (UV-Vis DRS), and powder X-ray diffraction (PXRD). Molecular interactions were analyzed via the 3D Hirshfeld surface method and 2D fingerprint mapping. The low bandgap (2.45 eV) indicates that this crystal is a semiconductor material suitable for optical applications. Microbial inhibition (MIC) experiments demonstrated its potent bactericidal activity against Escherichia coli and Staphylococcus aureus.
This study focuses on the synthesis and characterization of sorbents derived from vermiculite and copolymers designed to address the problem of water purification by removing toxic metal ions from aqueous environments. New polymer-mineral composites were synthesized by adsorption of the copolymers of 5-(4-nitro)-phenylazo-8-methacryloxyquinoline: methyl methacrylate and 8-methacryloxyquinoline-5-sulfonic acid: methyl methacrylate on the surface of vermiculite. FTIR and thermogravimetric analysis demonstrated the immobilization of copolymers on the surface of vermiculite. It has been established that the modification provides an increase in the sorption capacity of composites for ions Cu(& Iukcy;& Iukcy;), Cd(& Iukcy;& Iukcy;), Pb(& Iukcy;& Iukcy;), and Fe(& Iukcy;& Iukcy;& Iukcy;), which indicates the successful functionalization of the sorbent.
