Development of a large volume line scanning, high spectral range and resolution 3D hyperspectral photoluminescence imaging microscope for diamond and other high refractive index materials.

Hyperspectral photoluminescence (PL) imaging is a powerful technique that can be used to understand the spatial distribution of emitting species in many materials. Volumetric hyperspectral imaging of weakly emitting color centers often necessitates considerable data collection times when using commercial systems. We report the development of a line-scanning hyperspectral imaging microscope capable of measuring the luminescence emission spectra for diamond volumes up to 2.20 × 30.00 × 6.30 mm with a high lateral spatial resolution of 1-3 µm. In an single X-λ measurement, spectra covering a 711 nm range, in a band from 400-1100 nm, with a spectral resolution up to 0.25 nm can be acquired. Data sets can be acquired with 723 (X) × 643 (Y) × 1172 (λ) pixels at a rate of 6 minutes/planar image slice, allowing for volumetric hyperspectral imaging with high sampling. This instrument demonstrates the ability to detect emission from several different color centers in diamond both at the surface and internally, providing a non-destructive method to probe their 3D spatial distribution, and is currently not achievable with any other commonly used system or technique.

The prognostic significance of histologic variant on survival outcomes in patients with metastatic urothelial carcinoma receiving immune checkpoint inhibitor therapy.

BACKGROUND: While the treatment guidelines have been established for pure urothelial carcinoma (pUC), patients with variant type urothelial carcinoma (vUC) face limited effective treatment options. The effectiveness of immune checkpoint inhibitors (ICI) in patients with vUC remains uncertain and necessitates additional research. METHOD: We conducted a retrospective, multicenter study to explore the effectiveness of ICI in patients with pUC or vUC in Taiwan. We evaluated the overall response rate (ORR) through univariate logistic regression analysis and examined the overall survival (OS) and progression-free survival (PFS) using Kaplan-Meier analysis. Additionally, we employed univariate and multivariate Cox proportional hazards models to analyze the data. RESULT: A total of 142 patients (116 pUC, 26 vUC) were included in our final analysis. The ORR was marginally higher in patients with pUC compared to those with vUC (34.5% vs. 23.1%, p = 0.26). Among all patients, 12.9% with pUC achieved a complete response (CR) after ICI treatment, while no vUC cases achieved CR (p = 0.05). There were no significant differences in PFS (median 3.6 months vs. 4.1 months, p = 0.34) or OS (median 16.3 months vs. 11.0 months, p = 0.24) when comparing patients with pUC or vUC. In the subgroup analysis, patients with pUC who underwent first-line ICI treatment exhibited significantly improved OS compared to those with vUC (24.6 months vs. 9.1 months, p = 0.004). CONCLUSION: The use of ICI as monotherapy is a feasible and effective treatment approach for patients with metastatic vUC.

Imaging-assisted Raman and photoluminescence spectroscopy for diamond jewelry identification and evaluation.

Jewelry identification and evaluation are limited owing to interference from the surrounding metal mount and adjacent gemstones. To maintain transparency in the jewelry market, this study proposes imaging-assisted Raman and photoluminescence spectroscopy for jewelry measurement. The system can automatically measure multiple gemstones on a jewelry piece sequentially, using the image as a reference for alignment. The experimental prototype demonstrates the capability of noninvasive measurement for separating natural diamonds from their laboratory-grown counterparts and diamond simulants. Furthermore, the image can be used for gemstone color evaluation and weight estimation.

Joint Masked Face Recognition and Temperature Measurement System Using Convolutional Neural Networks.

With the outbreak of COVID-19, epidemic prevention has become a way to prevent the spread of epidemics. Many public places, such as hospitals, schools, and office places, require disinfection and temperature measurement. To implement epidemic prevention systems and reduce the risk of infection, it is a recent trend to measure body temperature through non-contact sensing systems with thermal imaging cameras. Compared to fingerprints and irises, face recognition is accurate and does not require close contact, which significantly reduces the risk of infection. However, masks block most facial features, resulting in the low accuracy of face recognition systems. This work combines masked face recognition with a thermal imaging camera for use as an automated attendance system. It can record body temperature and recognize the person at the same time. Through the designed UI system, we can search the attendance information of each person. We not only provide the design method based on convolutional neural networks (CNNs), but also provide the complete embedded system as a real demonstration and achieve a 94.1% accuracy rate of masked face recognition in the real world. With the face recognition system combined with a thermal imaging camera, the purpose of screening body temperature when checking in at work can be achieved.

Reversible photochromic effect in natural gemstone sapphires.

Photochromic sapphires show an optically controllable orange coloration under ambient temperatures, which strongly affects the color appearance and market value of gemstone sapphires. An in situ absorption spectroscopy technique using a tunable excitation light source has been developed to investigate the wavelength- and time-dependence of sapphire's photochromism. Excitations of ≤370 nm and ≥410 nm introduce and remove orange coloration, respectively, whereas there is a stable absorption band at 470 nm. Both the color enhancement and diminishing rates are proportional to the excitation intensity; hence, strong illumination can significantly accelerate the photochromic effect. Finally, the origin of the color center can be explained by a combination of the differential absorption and the opposite trends between the orange coloration and Cr3+ emission, indicating that the origin of this photochromic effect is related to a magnesium-induced trapped hole and chromium. The results can be used to minimize the photochromic effect and improve the reliability of color evaluation for valuable gemstones.

Rapid screening of a photochromic Padparadscha-like sapphire using absorption spectroscopy.

The Padparadscha sapphire is attracting increasing interest due to its unique color combination of pink and orange. However, some Padparadscha sapphires exhibit an unstable orange color component; the stone turns from pink to orangey pink after longwave ultraviolet (UV) radiation, and the orange color fades out under a room light or halogen light source. This is of interest and concern since accuracy and consistency are important in colored stone identification services. This study investigates the UV visible (UV-Vis) absorption spectra of photochromic Padparadscha sapphires under illumination of different wavelengths between 250 and 600 nm. Our results show that shortwave UV induces the orange color more effectively than longwave UV, and Vis light near 450 nm reduces the orange color more effectively than a halogen light source. Based on these findings, we developed a prototype UV-Vis absorption spectroscopy device with two fiber-coupled light-emitting diodes at 265 and 455 nm. It can perform rapid screening of photochromic Padparadscha sapphires and has faster color recovery compared to current techniques.

Automatic Optical Inspection System for Wire Color Sequence Detection.

Given the huge demand for wire in today's society, the quality of the wire is especially required. To control the quality of the produced wire, the industry has a great desire for automated optical inspection technology. This technology is a high-speed and highly accurate optical image inspection system that uses mechanical sensing equipment to replace the human eye as the inspection method and simulates manual operation by means of a robotic arm. In this paper, a high-performance algorithm for the automated optical inspection of wire color sequence is proposed. This paper focuses on the design of a high-speed wire color sequence detection that can automatically adapt to different kinds of wires and recognition situations, such as a single wire with only one color, and one or two wires covered with aluminum foil. To be further able to successfully inspect even if the wire is short in the screen and the two wires are close to each other, we calculate the horizontal gradient of the wires by edge detection and morphological calculation and identify the types and color sequences of the wires in the screen by a series of discriminative mechanisms. Experimental results show that this method can achieve good accuracy while maintaining a good computation speed.

Relationships between autistic traits, insufficient sleep, and real-world executive functions in children: a mediation analysis of a national epidemiological survey.

BACKGROUND: Although the literature documents low executive functions and sleep deficits in individuals with autism spectrum disorder or subclinical autistic traits, no study has simultaneously examined their relationships in the general child population. This study aimed to examine whether autistic traits impacted real-world executive functions through insufficient sleep in a nationally representative sample of children. METHODS: This was a national survey of 6832 primary and secondary school students, aged 8-14 years old, with equal sex distribution (3479 boys, 50.8%). Parents reported their child's nocturnal sleep duration and the need for sleep to maintain their daytime function and the Social Responsiveness Scale and the Behavior Rating Inventory of Executive Function (BRIEF) for their children's autistic traits and real-world executive functions, respectively. RESULTS: We found that autistic traits exerted indirect effects on real-world executive functions through sleep deficits, independent of sex, and age. Moreover, such an indirect effect was observed only from restricted and repetitive behaviors to executive functions through sleep deficits, but not in the other components of autistic traits (i.e. social communication and interaction). CONCLUSIONS: Our novel findings underscore the importance of sleep and autistic traits in executive functions and suggest potential mechanisms that may underlie the observed correlational structure among autistic behaviors, sleep deficits, and low executive function performance.

Rapid detection of color-treated pearls and separation of pearl types using fluorescence analysis.

Pearl identification plays a key role to maintain transparency in the gem industry by disclosing potential color treatments and classifying pearl species. Current techniques for pearl identification have been limited by expensive instrumentations and long measurement time, severely restricting their use outside of major gemological laboratories. There is a strong demand for simple and inexpensive identification instruments designed for non-specialized users and small-scale gemological laboratories. For this purpose, we demonstrate a portable fluorescence spectroscopy for pearl treatment detection and species classification based on pearl's nacre fluorescence detection. This device can be used to rapidly separate naturally colored pearls from treated colored pearls, detect potential treatments applied to white colored pearls, and separate pearls between certain species in seconds, based on their differences in nacre fluorescence intensity. The system enables noninvasive testing of loose pearls, pearl strands, and mounted pearl jewelry under normal office lighting conditions. The experimental prototype demonstrates high accuracy for automatic pearl color treatment screening, referring 100% of the treated colored pearls. Furthermore, similar protocols can be applied to evaluate popular pearl enhancements such as bleaching and to extend its application to separate akoya pearls and their South Sea counterparts.

Rapid gemstone screening and identification using fluorescence spectroscopy.

We demonstrate a gemstone screening device based on fluorescence spectroscopy. The device can be used to rapidly separate colorless and near-colorless (D to J color grades) natural diamonds from laboratory grown diamonds and diamond simulants, detect multi-treated pink diamonds, and identify certain colored gemstones, such as corundum, spinel, beryl, and zoisite. The device's reflection fiber probe enables testing of both loose and mounted gemstones with exposed facet faces that are larger than 0.9 mm. The experimental prototype demonstrates high accuracy for automatic diamond gemstone screening, referring 100% of the laboratory grown diamonds and simulants tested. The pink diamond screening algorithm can detect 100% of pink multi-treated diamonds and laboratory grown diamonds. Finally, the suitability of this device for the fluorescence analysis of corundum, beryl, spinel, zoisite, garnet, and topaz was evaluated.

Architecture Design and VLSI Implementation of 3D Hand Gesture Recognition System.

With advancements in technology, more and more research is being focused on enhancing daily life quality and convenience. Along with the increase in the development of gesture control systems, many controllers, such as the keyboard, mouse, and other devices, have been replaced with remote control products, which are gradually becoming more intuitive for users. However, vision-based hand gesture recognition systems still have many problems to overcome. Most hand detection methods adopt a skin filter or motion filter for pre-processing. However, in a noisy environment, it is not easy to correctly extract interesting objects. In this paper, a VLSI design with dual-cameras has been proposed to construct a depth map with a stereo matching algorithm and recognize hand gestures. The proposed system adopts an adaptive depth filter to separate interesting foreground objects from the background. We also propose dynamic gesture recognition using depth and coordinate information. The system can perform static and dynamic gesture recognition. The ASIC design is implemented in TSMC 90 nm with about 47.3 K gate counts, and 27.8 mW of power consumption. The average accuracy of each gesture recognition is 83.98%.

Interplay Between Hydroxyl Density and Relaxations in Poly(vinylbenzyltrimethylammonium)-b-poly(methylbutylene) Membranes for Electrochemical Applications.

Anion-exchange membranes (AEMs) consisting of poly(vinyl benzyl trimethylammonium)-b-poly(methylbutylene) of three different ion exchange capacities (IECs), 1.14, 1.64, and 2.03 mequiv g-1, are studied by High-Resolution Thermogravimetry, Modulated Differential Scanning Calorimetry, Dynamic Mechanical Analysis, and Broadband Electrical Spectroscopy in their OH- form. The thermal stability and transitions are elucidated, showing a low temperature Tg and a higher temperature transition assigned to a disorder-order transition, Tδ, which depends on the IEC of the material. The electric response is analyzed in detail, allowing the identification of three polarizations (only two of which contribute significantly to the overall conductivity, σEP and σIP,1) and two dielectric relaxation events (ß1 and ß2), one associated with the tolyl side groups (ß1) and one with the cationic side chains (ß2). The obtained results are integrated in a coherent picture and a conductivity mechanism is proposed, involving two distinct conduction pathways, σEP and σIP,1. Importantly, we observed a reordering of the ion pair dipoles which is responsible for the Tδ at temperatures higher than 20 °C, which results in a dramatic decrease of the ionic conductivity. Clustering is highly implicated in the higher IEC membrane in the hydroxyl form, which reduces the efficiency of the anionic transport.

Single-sensor multispeaker listening with acoustic metamaterials.

Designing a "cocktail party listener" that functionally mimics the selective perception of a human auditory system has been pursued over the past decades. By exploiting acoustic metamaterials and compressive sensing, we present here a single-sensor listening device that separates simultaneous overlapping sounds from different sources. The device with a compact array of resonant metamaterials is demonstrated to distinguish three overlapping and independent sources with 96.67% correct audio recognition. Segregation of the audio signals is achieved using physical layer encoding without relying on source characteristics. This hardware approach to multichannel source separation can be applied to robust speech recognition and hearing aids and may be extended to other acoustic imaging and sensing applications.

Endoscopic forward-viewing optical coherence tomography and angiography with MHz swept source.

Endoscopic optical coherence tomography (OCT) instruments are mostly side viewing and rely on at least one proximal scan, thus limiting accuracy of volumetric imaging and en face visualization. Previous forward-viewing OCT devices had limited axial scan speeds. We report a forward-viewing fiber scanning 3D-OCT probe with 900 µm field of view and 5 µm transverse resolution, imaging at 1 MHz axial scan rate in the human gastrointestinal tract. The probe is 3.3 mm diameter and 20 mm rigid length, thus enabling passage through the endoscopic channel. The scanner has 1.8 kHz resonant frequency, and each volumetric acquisition takes 0.17 s with 2 volumes/s display. 3D-OCT and angiography imaging of the colon was performed during surveillance colonoscopy.

Intellectual disability-associated dBRWD3 regulates gene expression through inhibition of HIRA/YEM-mediated chromatin deposition of histone H3.3.

Many causal mutations of intellectual disability have been found in genes involved in epigenetic regulations. Replication-independent deposition of the histone H3.3 variant by the HIRA complex is a prominent nucleosome replacement mechanism affecting gene transcription, especially in postmitotic neurons. However, how HIRA-mediated H3.3 deposition is regulated in these cells remains unclear. Here, we report that dBRWD3, the Drosophila ortholog of the intellectual disability gene BRWD3, regulates gene expression through H3.3, HIRA, and its associated chaperone Yemanuclein (YEM), the fly ortholog of mammalian Ubinuclein1. In dBRWD3 mutants, increased H3.3 levels disrupt gene expression, dendritic morphogenesis, and sensory organ differentiation. Inactivation of yem or H3.3 remarkably suppresses the global transcriptome changes and various developmental defects caused by dBRWD3 mutations. Our work thus establishes a previously unknown negative regulation of H3.3 and advances our understanding of BRWD3-dependent intellectual disability.

Dynamic Gradient Directed Molecular Transport and Concentration in Hydrogel Films.

Materials which selectively transport molecules along defined paths offer new opportunities for concentrating, processing and sensing chemical and biological agents. Here, we present the use of traveling ionic waves to drive molecular transport and concentration of hydrophilic molecules entrained within a hydrogel. The traveling ionic wave is triggered by the spatially localized introduction of ions, which through a dissipative ion exchange process, converts quaternary ammonium groups in the hydrogel from hydrophilic to hydrophobic. Through a reaction-diffusion process, the hydrophobic region expands with a sharp transition at the leading edge; it is this sharp gradient in hydrophilicity that drives the transport of hydrophilic molecules dispersed within the film. The traveling wave moved up to 450 µm within 30 min, while the gradient length remained 20 µm over this time. As an example of the potential of molecular concentration using this approach, a 70-fold concentration of a hydrophilic dye was demonstrated.

Spatial light modulator based color polarization imaging.

We describe a compressive snapshot color polarization imager that encodes spatial, spectral, and polarization information using a liquid crystal modulator. We experimentally show that polarization imaging is compressible by multiplexing polarization states and present the reconstruction results. This compressive camera captures the spatial distribution of four polarizations and three color channels. It achieves <0.027° spatial resolution, 10(3) average extinction ratio, and >30 PSNR.

Spectral-temporal compressive imaging.

This Letter presents a compressive camera that integrates mechanical translation and spectral dispersion to compress a multi-spectral, high-speed scene onto a monochrome, video-rate detector. Experimental reconstructions of 17 spectral channels and 11 temporal channels from a single measurement are reported for a megapixel-scale monochrome camera.

Interplay between solid state transitions, conductivity mechanisms, and electrical relaxations in a [PVBTMA] [Br]-b-PMB diblock copolymer membrane for electrochemical applications.

Understanding the structure-property relationships and the phenomena responsible for ion conduction is one of the keys in the design of novel ionomers with improved properties. In this report, the morphology and the mechanism of ion exchange in a model anion exchange membrane (AEM), poly(vinyl benzyl trimethyl ammonium bromide)-block-poly(methylbutylene) ([PVBTMA][Br]-b-PMB), is investigated with small angle X-ray scattering, high-resolution thermogravimetry, modulated differential scanning calorimetry, dynamic mechanical analysis, and broadband electrical spectroscopy. The hyper-morphology of the material consists of hydrophilic domains characterized by stacked sides of [PVBTMA][Br] which are sandwiched between "spaghetti-like" hydrophobic cylindrical parallel domains of the PMB block. The most important interactions in the hydrophilic domains occur between the dipoles of ammonium bromide ion pairs in the side chains of adjacent chains. A reordering of the ion pair dipoles is responsible for a disorder-order transition (Tδ) at high temperature, observed here for the first time in AEMs, which results in a dramatic decrease of the ionic conductivity. The overall mechanism of long range charge transfer, deduced from a congruent picture of all of the results, involves two distinct ion conduction pathways. In these pathways, hydration and the motion of the ionic side groups are crucial to the conductivity of the AEM. Unlike the typical perfluorinated sulfonated proton-conducting polymer, the segmental motion of the backbone is negligible.

Water uptake profile in a model ion-exchange membrane: conditions for water-rich channels.

Ionic conductivity in a polymeric fuel cell requires water uptake. Previous theoretical studies of water uptake used idealized parameters. We report a parameter-free prediction of the water-swelling behavior of a model fuel cell membrane. The model polymers, poly(methyl-butylene)-block-poly(vinylbenzyl-trimethylamine), form lamellar domains that absorb water in humid air. We use the Scheutjens-Fleer methodology to predict the resulting change in lamellar structure and compare with x-ray scattering. The results suggest locally uniform water distributions. However, under conditions where a PVBTMA and water mixture phase-separate, the two phases arrange into stripes with a dilute stripe sandwiched between two concentrated stripes. A small amount of water enhances conductivity most when it is partitioned into such channels, improving fuel-cell performance.