22 research outputs found
Frequency-aware optical coherence tomography image super-resolution via conditional generative adversarial neural network
Optical coherence tomography (OCT) has stimulated a wide range of medical
image-based diagnosis and treatment in fields such as cardiology and
ophthalmology. Such applications can be further facilitated by deep
learning-based super-resolution technology, which improves the capability of
resolving morphological structures. However, existing deep learning-based
method only focuses on spatial distribution and disregard frequency fidelity in
image reconstruction, leading to a frequency bias. To overcome this limitation,
we propose a frequency-aware super-resolution framework that integrates three
critical frequency-based modules (i.e., frequency transformation, frequency
skip connection, and frequency alignment) and frequency-based loss function
into a conditional generative adversarial network (cGAN). We conducted a
large-scale quantitative study from an existing coronary OCT dataset to
demonstrate the superiority of our proposed framework over existing deep
learning frameworks. In addition, we confirmed the generalizability of our
framework by applying it to fish corneal images and rat retinal images,
demonstrating its capability to super-resolve morphological details in eye
imaging.Comment: 13 pages, 7 figures, submitted to Biomedical Optics Express special
issu
SCPAT-GAN: Structural Constrained and Pathology Aware Convolutional Transformer-GAN for Virtual Histology Staining of Human Coronary OCT images
There is a significant need for the generation of virtual histological
information from coronary optical coherence tomography (OCT) images to better
guide the treatment of coronary artery disease. However, existing methods
either require a large pixel-wisely paired training dataset or have limited
capability to map pathological regions. To address these issues, we proposed a
structural constrained, pathology aware, transformer generative adversarial
network, namely SCPAT-GAN, to generate virtual stained H&E histology from OCT
images. The proposed SCPAT-GAN advances existing methods via a novel design to
impose pathological guidance on structural layers using transformer-based
network.Comment: 9 pages, 4 figure
Thermal Annealing of Exfoliated Graphene
Monolayer graphene is obtained by mechanical exfoliation using scotch tapes. The effects of thermal annealing on the tape residues and edges of graphene are researched. Atomic force microscope images showed that almost all the residues could be removed in N2/H2 at 400°C but only agglomerated in vacuum. Raman spectra of the annealed graphene show both the 2D peak and G peak blueshift. The full width at half maximum (FWHM) of the 2D peak becomes larger and the intensity ratio of the 2D peak to G peak decreases. The edges of graphene are completely attached to the surface of the substrate after annealing
CMTM6 shapes antitumor T cell response through modulating protein expression of CD58 and PD-L1
The dysregulated expression of immune checkpoint molecules enables cancer cells to evade immune destruction. While blockade of inhibitory immune checkpoints like PD-L1 forms the basis of current cancer immunotherapies, a deficiency in costimulatory signals can render these therapies futile. CD58, a costimulatory ligand, plays a crucial role in antitumor immune responses, but the mechanisms controlling its expression remain unclear. Using two systematic approaches, we reveal that CMTM6 positively regulates CD58 expression. Notably, CMTM6 interacts with both CD58 and PD-L1, maintaining the expression of these two immune checkpoint ligands with opposing functions. Functionally, the presence of CMTM6 and CD58 on tumor cells significantly affects T cell-tumor interactions and response to PD-L1-PD-1 blockade. Collectively, these findings provide fundamental insights into CD58 regulation, uncover a shared regulator of stimulatory and inhibitory immune checkpoints, and highlight the importance of tumor-intrinsic CMTM6 and CD58 expression in antitumor immune responses
Controlling Dispersion Characteristic of Focused Vortex Beam Generation
As an important structured beam, vortex beams have a wide range of applications in many fields. However, conventional vortex beam generators require complex optical systems, and this problem is particularly serious with regards to focused vortex beam generators. The emergence of metasurfaces provides a new idea for solving this problem; however, the accompanying chromatic dispersion limits its practical application. In this paper, we show that the dispersion characteristic of focused vortex beam generators based on metasurfaces can be controlled by simultaneously manipulating the geometric and propagative phases. The simulation results show that the transmission-type focused vortex beam generators exhibit positive dispersion, zero dispersion, and negative dispersion, respectively. This work paves the way for the practical application of focused vortex beam generators
Controlling Dispersion Characteristic of Focused Vortex Beam Generation
As an important structured beam, vortex beams have a wide range of applications in many fields. However, conventional vortex beam generators require complex optical systems, and this problem is particularly serious with regards to focused vortex beam generators. The emergence of metasurfaces provides a new idea for solving this problem; however, the accompanying chromatic dispersion limits its practical application. In this paper, we show that the dispersion characteristic of focused vortex beam generators based on metasurfaces can be controlled by simultaneously manipulating the geometric and propagative phases. The simulation results show that the transmission-type focused vortex beam generators exhibit positive dispersion, zero dispersion, and negative dispersion, respectively. This work paves the way for the practical application of focused vortex beam generators
Preparation of Medium Density Fiberboard from Wood Fibers Catalytically Oxidized by Laccase-Mediator System
Laccase, an enzyme capable of degrading lignin, has become an effective agent for green processing and has great significance for the protection of the environment and the development of a low-carbon economy. In this work, wood fibers were selected as the raw material, and with activation by a laccase-mediator system, lignin was changed to a natural adhesive material, and the high temperature/high pressure method was used to prepare medium density fiberboard (MDF). The bonding mechanism was explored with measurements of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscope (ESEM), and X-ray diffraction (XRD). It was found that the self-adhesive effect was realized through esterification, hydrogen bonding, polycondensation, coupling, and a Schiff base reaction, among which coupling and polycondensation were the primary reactions. The chemical bonds between the MDF interior and surface varied because of the mobility of the lignin during the reaction
Controlled synthesis of single-crystalline graphene
This paper reports the controlled synthesis of single-crystalline graphene on the back side of copper foil using CH4 as the precursor. The influence of growth time and the pressure ratio of CH4/H2 on the structure of graphene are examined. An optimized polymer-assisted method is used to transfer the synthesized graphene onto a SiO2/Si substrate. Scanning electron microscopy and Raman spectroscopy are used to characterize the graphene