Deep Learning-Based Universal Expert-Level Recognizing Pathological Images of Hepatocellular Carcinoma and Beyond.

Background and Aims: We aim to develop a diagnostic tool for pathological-image classification using transfer learning that can be applied to diverse tumor types. Methods: Microscopic images of liver tissue with and without hepatocellular carcinoma (HCC) were used to train and validate the classification framework based on a convolutional neural network. To evaluate the universal classification performance of the artificial intelligence (AI) framework, histological images from colorectal tissue and the breast were collected. Images for the training and validation sets were obtained from the Xiamen Hospital of Traditional Chinese Medicine, and those for the test set were collected from Zhongshan Hospital Xiamen University. The accuracy, sensitivity, and specificity values for the proposed framework were reported and compared with those of human image interpretation. Results: In the human-machine comparisons, the sensitivity, and specificity for the AI algorithm were 98.0, and 99.0%, whereas for the human experts, the sensitivity ranged between 86.0 and 97.0%, while the specificity ranged between 91.0 and 100%. Based on transfer learning, the accuracies of the AI framework in classifying colorectal carcinoma and breast invasive ductal carcinoma were 96.8 and 96.0%, respectively. Conclusion: The performance of the proposed AI framework in classifying histological images with HCC was comparable to the classification performance achieved by human experts, indicating that extending the proposed AI's application to diagnoses and treatment recommendations is a promising area for future investigation.

Obliquely Deposited Titanium Nitride Nanorod Arrays as Surface-Enhanced Raman Scattering Substrates.

In this work, titanium nitride (TiN) nanorod arrays were prepared as surface-enhanced Raman scattering (SERS) substrates using glancing angle deposition (GLAD) in a magnetron sputtering system. The nitrogen flow rate was varied from RN2 = 1 to 3 sccm, yielding five TiN uniform thin films and five TiN nanorod arrays. The figure of merit (FOM) of each TiN uniform film was measured and compared with the SERS signal of each TiN nanorod array. Rhodamine 6G (R6G) was used as the analyte in SERS measurement. For an R6G concentration of 10-6 M, the analytical enhancement factor (AEF) of the TiN nanorod array that was prepared at RN2 = 1.5 sccm was 104. The time-durable SERS performance of TiN nanorod arrays was also investigated.

Capping metallic nanohelixes with SiO2 nanohelixes to enhance broadband and wide-angle light extinction.

In this work, an SiO2 nanohelix array is obliquely deposited upon a metal nanohelix array as an index matching layer to enhance light extinction. Firstly, an SiO2-Ag nanohelix array is fabricated with stronger light extinction than the Ag nanohelix array over wavelengths from 300 nm to 1000 nm at normal incidence. Next, the SiO2-Al-Ag nanohelix array is fabricated; it exhibits broadband and wide-angle light extinction that is stronger that reported for the Al-Ag nanohelix array. The unpolarized extinctance exceeds 90% over wavelengths from 400 nm to 2000 nm and angles of incidence from 0° to 70°.

An interference coating of metamaterial as an ultrathin light absorber in the violet-to-infrared regime.

A metamaterial with brief and ultrathin structure performs high efficiency in light absorption. An upright aluminum nanorod array (Al NRA) is obliquely deposited, measured, and analyzed its optical property. The Al NRA performs high efficiency of light absorption and low reflectance simultaneously. Based on the measured refractive index and impedances, the wave propagation through the Al NRA is traced to demonstrate the destructive interference that leads to antireflection. According to the analysis of wave tracing, an Al semicontinuous film with thickness of 15nm is introduced under an Al NRA with thickness of only 245nm as a brief and thin two-layered structure. The broadband and polarization-independent light absorption is measured over the violet-to-infrared regime.

Metal/dielectric/metal sandwich film for broadband reflection reduction.

A film comprising randomly distributed metal/dielectric/metal sandwich nanopillars with a distribution of cross-sectional diameters, displayed extremely low reflectance over the blue-to-red regime, when coated on glass and illuminated normally. When it is illuminated by normally incident light, this sandwich film (SWF) has a low extinction coefficient, its phase thickness is close to a negative wavelength in the blue-to-red spectral regime, and it provides weakly dispersive forward and backward impedances, so that reflected waves from the two faces of the SWF interfere destructively. Broadband reflection-reduction, over a wide range of incidence angles and regardless of the polarization state of the incident light, was observed when the SWF was deposited on polished silicon.

Extended broadband achromatic reflective-type waveplate.

This work demonstrates the feasibility of applying a symmetrical film stack on a silver mirror, resulting in broadband phase retardation. While functioning as a reflective-type achromatic waveplate, the symmetrical film stack comprises at least one anisotropic thin film. Additionally, selecting the birefringence and thickness of the thin film allows for the design of uniform phase retardation in both the passband and stopband. A symmetrical film stack that is composed of an anisotropic Ta(2)O(5) thin film and isotropic Ta(2)O(5) thin film is investigated for its achromatic performance in phase retardation.

Biologically inspired achromatic waveplates for visible light.

Waveplates are planar devices used in optics and optoelectronics to change the polarization state of light. Made of anisotropic dielectric materials such as crystals and thin films, waveplates are not known to exhibit achromatic performance over the visible regime. Inspired by the microvillar structure of R8 cells functioning as polarization converters in the eyes of stomatopod crustaceans, we conceived, designed, fabricated and tested periodically multilayered structures comprising two different types of arrays of nanorods. Morphologically analogous to the ocular cells, here we show that the periodically multilayered structures can function as achromatic waveplates over the visible regime.