Browse Articles

GTPBP2 inactivates Hippo signaling to promote triple-negative breast cancer cell malignancy

Light-induced damage in semiconductor device manufacturing: Present and future challenges

Advances in semiconductor manufacturing over the past few decades, driven by the need for smaller, faster, and more efficient devices, have pushed enormous progress in light sources for lithography and metrology. However, the smaller feature sizes and more costly wafer real estate necessitate smaller spot sizes, smaller test/alignment markers, and higher light intensities. This combination has made light-induced damage an obstacle to fast, reliable wafer-lithography, -metrology, -leveling, and -alignment. In this perspective, we address the challenges of light-induced damage for semiconductor manufacturing, highlighting the light sources, materials, device stacks, and damage mechanisms at play. Furthermore, we provide a perspective into the future of the industry and of new materials, which provide new functionality, but may be more sensitive to light-induced damage. Finally, we discuss how light-induced damage can be used constructively, for instance, in direct laser writing or material processing.

Anatomical and physiological traits to identify low-vigor Persian walnut accessions as candidate dwarfing rootstocks

Exceptional point driven by asymmetry in meta-resonators in a non-Hermitian complementary terahertz metasurface

In this paper, we investigate a non-Hermitian open terahertz metasurface comprising complementary structures capable of exhibiting parity-time symmetry. The metasurface consists of two asymmetric resonators of different sizes, representing effective gain and loss elements, placed orthogonally in a strongly coupled near-field configuration. When one resonator is displaced diagonally with respect to the other, the exceptional point appears where the system undergoes a phase transition from a PT-symmetric to a PT-asymmetric state. We fabricate the samples in a clean room ambience to experimentally validate the exceptional points. Terahertz time-domain spectroscopy is performed on the fabricated samples to experimentally corroborate the transmission properties observed in numerical simulations. We further employ coupled mode theory to analyze and distinguish between the PT-symmetric state, exceptional point, and PT-asymmetric state. Theoretical framework enables the calculation of eigenvalues, phase spectra, and eigenmodes associated with the metamaterial design, thereby again corroborating the simulation results. Furthermore, we construct the Poincaré sphere to visualize the orientation of the polarization states of the eigenmodes, which again suggest the presence of an exceptional point. The study holds potential to develop highly sensitive terahertz devices, addressing limitations of conventional PT-symmetric systems that rely on traditional gain and loss media.

Switching single and dual wavelength emission in a quasi-three-level Nd: YLF laser by adjusting pump beam waist position

Fast steady-state simulation of electrospray thruster plumes using tracer particles

This paper presents a new method for steady-state simulation of an electrospray thruster exhaust plume. The method, iterative tracer particle (ITP), leverages the similarity between an electrospray thruster exhaust plume and a heavy ion beam to employ tracer particles in order to determine the charge density distribution in the steady-state plume. The solutions from ITP are validated against the commonly used particle-in-cell method for an axisymmetric simulation domain, demonstrating solution consistency (<1% error) with a factor of 30 reduction in processing time and a factor of 25 reduction in memory usage depending on the test case. This reduction in computational time and memory enables faster and efficient studies of electrospray plume dynamics and potentially enables the ability to solve the inverse problem of relating downstream experimental plume measurements to the unobservable properties of the plume at emission. A basic implementation of the ITP approach is included in the supplementary material.

A geometric morphometrics approach to sex estimation of infants from 0 to 6 years using the auricular surface

Abstract Estimating biological sex is an essential tool for studying past population dynamics and cultural behaviour. Typically, it is not performed in non-adults before the onset of puberty, limiting the knowledge that can be gained from immature skeletal remains. This study used three-dimensional (3D) geometric morphometrics (GM) to examine sexual dimorphism and assess its effectiveness in estimating biological sex in infants aged 0–6 years using the auricular surface of the ilium. This approach was tested with 46 individuals (20 females and 26 males) from the Lisbon Identified Skeletal Collection. All specimens were digitised, and standard GM analysis was conducted. Apparent sex-related morphological differences in the auricular surface were observed in infants under one year, although these did not reach statistical significance at α = 0.05. Such differences were not identified in older individuals. These findings suggest that the auricular surface may potentially serve as a sex indicator in infants under one year, whereas sexual dimorphism appears to decrease in older individuals. This study demonstrates the potential of employing 3D GM for sex estimation in non-adult skeletal remains. Further research should explore additional iliac features for infant sex estimation, incorporate larger and more diverse samples, and potentially include Artificial Intelligence techniques.

Chemical composition and spatial distribution of plasma species in inductively coupled N2–O2 plasmas: Insights from a 2D fluid model

The investigation of N2–O2 discharges is critically important for optimizing photoresist ashing efficiency and controlling plasma-induced damage in advanced semiconductor manufacturing. This study employs a two-dimensional fluid model to investigate the plasma characteristics of N2–O2 radio frequency inductively coupled discharges, with particular focus on the effects of N2 fraction, discharge power, and gas pressure on particle spatial distribution and chemical composition. Our results demonstrate that the plasma's chemical composition is determined by the N2 fraction. Specifically, N2+ and O2+ are the major ion species within the N2 fraction range of 50%–70%, whereas N2+ become predominant at 90% N2 fraction. This change in composition can be attributed to the competition between electron-impact ionization and charge exchange reactions. At elevated N2 ratios, the balance between ion transport and ionization source terms results in a spatial distribution of NO+ ions characterized by two high-density regions. Furthermore, when the nitrogen fraction is fixed at 50%, the discharge power has little effect on the relative proportion of chemical components, but it significantly increases the particle density. In contrast, the pressure not only affects the particle density but also significantly influences the relative proportion of the plasma's chemical components. Moreover, the results demonstrate that the surface loss coefficient predominantly governs the density of the corresponding species, exerting minimal influence on other species. The findings of this work enhance the understanding of the physical processes in RF inductively coupled N2–O2 discharges and provide essential insights for optimizing N2–O2 mixed-gas plasma processes in semiconductor manufacturing.

A stress-controlled reservoir formation model for ultra-deep sandstones in foreland thrust belts: case study of the cretaceous bashijiqike formation, bozi-dabei area, kuqa depression, tarim basin

Continuously tunable terahertz spatiotemporal vortex generator enabled by magneto-optical effects

Spatiotemporal optical vortices (STOVs), characterized by transverse orbital angular momentum perpendicular to the pulse propagation direction, have shown great potential in a wide range of applications. While various methods have been developed to stably generate STOVs, schemes enabling actively tunable and independently controllable spatiotemporal vortex characteristics remain scarce. This study proposes and theoretically validates a general scheme for tuning terahertz spatiotemporal optical vortices by deliberately breaking the time-reversal symmetry of the system. The scheme can be implemented either by controlling material losses or by introducing magneto-optical (MO) effects, and this work focuses on the MO route. Using a magneto-dielectric misaligned nanograting as the platform, we induce tunable intrinsic topological singularities in the frequency–momentum space. By tuning the strength and orientation of the external magnetic field to modify the symmetry breaking of the resonant mode coupling matrix, we achieve active control over the central frequency and wave vector of the topological singularities, and reconstruct and generate terahertz spatiotemporal optical vortices wave packets at different frequencies within a finite and fixed wave vector range. In addition, this approach also provides an effective strategy to compensate for singularity shifts and wave packet distortions induced by material losses, offering a new pathway toward actively tunable spatiotemporal vortex devices in the terahertz regime.

Predicting infected pancreatic necrosis in acute pancreatitis using machine learning models and feature selection

Solving forward and inverse problems for atmospheric radio frequency discharge by Physics-Informed Neural Networks

With the requirement of intelligent control of atmospheric plasmas system, more Artificial Intelligence (AI) algorithms should be introduced into the field of plasma simulation. In this study, an innovative Physics-Informed Neural Networks (PINNs) framework for solving both forward and inverse problems in atmospheric radio frequency (RF) plasma is explored. For forward problems, the PINNs architecture with multi-scale feature is established by coupling Poisson’s equation, continuity equations, and drift-diffusion approximation equations into the loss function, to successfully capture the key plasma characteristics, showing good agreement with results from fluid simulation by discretization methods. For inverse problems that usually cannot be solved by discretization methods, by incorporating additional simulated (or measured) data of electric field as constraints in loss function, PINNs can accurately infer the applied voltage with relative errors smaller than 1%. The influence of various sampling positions, number of sampling points, and noise on the inversion of discharge parameter by PINNs is also investigated. In this study, according to the computational data, this mesh-less approach of PINNs successfully solves the fluid equations without relying on discretization methods and also shows the ability to inverse the discharge parameters such as applied voltage, driving frequency, or electrode spacing, given the data of electric field or plasma density, offering novel methodologies and insights for the intelligent control of atmospheric plasma systems.

Explainable and secure federated learning for privacy-enhancing skin cancer classification using a lightweight multi-scale CNN

Impact of reverse flow induced by a sawtooth anode on the performance of an argon Hall thruster

This study reports the performance comparison of the RAIJIN-66 TAL-type Hall thruster with argon propellant, using two hollow anode designs, one with a simple straight shape and another one with a sawtooth shape. Simulations of the rarefied gas in the sawtooth hollow anode region suggest a successful reversal of the direction of neutral particle flow, with an average increase in the neutral particle density by 15.5% when compared to the straight-shaped hollow anode. This contributes to the improvement in performance across a range of discharge voltages that was measured experimentally. When the thruster is operated with a discharge voltage of 150 V and a flow rate of 70 SCCM, the propellant utilization efficiency with the straight anode is 14%, while with the sawtooth anode it is 25.1%. The anode efficiency reaches in the vicinity of 15% with the sawtooth anode in high voltage conditions, exceeding the efficiencies achieved with the straight anode in the same operating conditions. The optimal magnetic field condition for argon operation and the tuning parameters of the sawtooth anode design for RAIJIN-66 are also discussed.

The effect of unilateral cortical blindness on lane position and gaze behavior in a virtual reality steering task

Abstract Adults with cortically-induced blindness (CB) affecting a quarter to a half of their visual field show greater variability in lane positioning when steering compared to those with intact vision. Because humans rely on visual information from optic flow to control steering, we hypothesized that these lane biases are caused in part by a disruption to motion processing caused by CB. To investigate, we examined the steering behavior of 21 CB drivers (11 left-sided, 10 right-sided visual deficits) and 9 visually intact controls in a closed-loop virtual reality steering task. Participants were instructed to maintain a central lane position while traveling at 19 m/s along a procedurally generated single-lane road. Turn direction (left/right) and turn radius (35m/55m/75m) varied between trials, and the quality of optic flow information was indirectly manipulated by altering the environmental texture density (low/medium/high). Right-sided CB participants maintained a similar average distance from the inner road edge as controls. Those with left-sided CB were less affected by changes in optic flow and turn direction. These differences were not explained by age, time since stroke, sparing of central vision, gaze direction, or saccade rate. Our results suggest that some left-sided CB participants place a lower weighting on optic flow information in the control of steering, possibly as a result of lateralization in the processing of motion. More broadly, our findings show that CB steering and gaze behavior are remarkably preserved despite the presence of visual deficits across large portions of the visual field.

High-stability sound transmission loss measurement method for acoustic metamaterials under grazing flow conditions

With the advancement of the practical application research of acoustic metamaterials, their performance under flow conditions becomes increasingly critical. However, the presence of flow field influences will greatly increase the complexity of predicting and evaluating acoustic metamaterial characteristics. Reliable results can be obtained through experimental methods, yet they face challenges in achieving high precision and stability under flow conditions. To overcome these challenges, this study proposes a High-stability Measurement Method (HSMM) for measuring sound transmission loss (STL) under grazing flow. The conventional scattering matrix describes the system performance of the sample and specific boundary rather than the inherent properties of the sample itself. In addition, the conventional transfer matrix is unaffected by the boundary conditions, but it has high requirements for the testing environment. Based on this, by introducing the self-spectrum and cross-spectrum signal processing methods into the transfer matrix method, we derive an adjusted transfer function Hij for STL calculation. This study examines two acoustic structures through both numerical simulation and experimental validation using the HSMM. The results demonstrate that the proposed HSMM can significantly reduce the outliers and data fluctuations compared to the conventional transfer matrix method, demonstrating superior measurement stability. The experimental results are in good agreement with the numerical simulation results; validating STL in the range of 1–1600 Hz can be accurately measured under grazing flow conditions.

The intention of Chinese college students to use sports smart wearable devices based on the technology acceptance model and technology readiness index

Microsecond carrier lifetime measurement using extended time-resolved THz spectroscopy

This study presents a terahertz (THz) spectroscopy platform for the comprehensive characterization of charge carrier dynamics in photovoltaic (PV) materials. The system integrates steady-state conductivity measurements with electronically synchronized diode pump–THz probe measurements, enabling both equilibrium and non-equilibrium analyses of carrier behavior in silicon (Si) and germanium (Ge). In steady-state mode, frequency-dependent conductivity is extracted via Drude model analysis to obtain carrier scattering time and mobility. From the equilibrium carrier distribution, we determine an effective carrier lifetime that reflects the balance between the generation, diffusion, and recombination processes. The time-resolved component extends the measurements to the microsecond regime using pulsed diode laser excitation synchronized with the THz probe. This enables direct observation of carrier decay dynamics and reveals significantly longer lifetimes than those obtained from steady-state measurements, indicating fundamentally different physical processes governing each approach. Numerical simulations reconcile this discrepancy by capturing how spatial carrier distributions differ under steady-state and transient conditions. Under steady-state conditions, the effective lifetime is reduced due to constant carrier generation near the surface and continuous surface recombination. After pulsed-laser excitation, carrier diffusion toward the bulk reduces surface recombination and yields a longer transient lifetime. This shift in the spatial carrier distribution leads to differences in the observed lifetime and highlights the value of combined steady-state and time-resolved THz approaches for semiconductor characterization. The platform provides detailed insights into both microscopic transport properties and macroscopic carrier dynamics, supporting the optimized design of PV devices.

Micronucleus quantification from whole-slide haematology images using AI serves as a translatable pharmacodynamic biomarker for DNA damage response inhibitors

Abstract Micronuclei are widely recognised biomarkers of genomic instability and DNA damage, making their accurate quantification essential for understanding the pharmacodynamic properties of chemotherapeutic agents and inhibitors of the DNA damage response (DDR). Here, we report the development and validation of a novel assay for the automated detection and quantification of micronuclei within circulating red blood cells (RBC) from peripheral blood smears. We integrate recent advances in whole-slide imaging (WSI) technologies and supervised deep-learning algorithms to quantify micronuclei in over 100,000 RBCs from a single image. We demonstrate that this approach achieves strong analytical concordance with flow cytometry (Pearson’s r = 0.926, P < 0.0001) while offering distinct advantages. Additionally, using May-Grünwald Giemsa dyes we show that deep-learning algorithms can stratify red blood cells into both mature erythrocytes and immature reticulocytes from WSIs. Critically, we establish that micronuclei-positive red blood cell (MN + -RBC) frequency correlates with anti-tumor efficacy in BRCA1 -deficient xenograft models following exposure to PARP inhibitors and demonstrates dose-dependent pharmacodynamic (PD) responses. Furthermore, we show that whole-slide imaging offers several advantages over widely used flow cytometry approaches, including the identification of cells with multiple micronuclei and the ability to quantify morphological features associated with detrimental pre-analytical conditions. These findings position automated WSI-based micronucleus quantification as a scalable, minimally invasive PD biomarker requiring only 5 μl of blood that enables longitudinal monitoring of DDR inhibitor therapies.

Phase transformation via optimal impregnation to enhance dielectric performance of polypropylene

The development of smart grids and new power systems has imposed higher requirements on the dielectric performance of polypropylene (PP) in oil-impregnated capacitors. Herein, the dielectric properties of PP films are successfully improved by adjusting their crystalline characteristics. The results demonstrate that under the optimal impregnation process, the capillary effect enhances impregnation efficiency, thereby inducing superior compatibility between the PP films and oil. This facilitates the phase transformation of β-crystals into α-crystals with a more perfect crystal structure during high-temperature impregnation. The resultant increase in the α-crystal content is accompanied by a corresponding enhancement in overall crystallinity. It consequently increases the dielectric constant of PP, while retaining an extremely low dielectric loss. Notably, the phase transformation also hinders the mobility of PP molecular chains, thereby weakening the charge energy accumulation process. These synergistic effects lead to a breakdown strength of up to 537 kV/mm, representing an 11.0% increase compared with the unimpregnated PP films. This study proposes a promising strategy for enhancing the dielectric performance of PP via phase regulation, which paves the way for its application in high-performance capacitors.