Browse Articles

Prognostic factors and development of the practical prediction score for 7-day mortality of palliative patients in the emergency department

Persistent austral winter storm track weakening beyond doubling of CO2 concentrations

Future roles of solid-state quantum dot light sources

This paper highlights the critical role of solid-state quantum dot (QD) light sources in both classical and quantum applications, with an emphasis on their integration with silicon photonics to advance future optical networks and quantum technologies. Quantum dot lasers, renowned for their low threshold currents, temperature stability, low-noise optical amplification, and enhanced coherence, are highlighted as essential components for scalable quantum systems. These features contribute to improved chip architectures, reduced module sizes, and increased channel density. The paper also explores the synergy between quantum dot lasers and silicon photonics in the generation of frequency combs, optimizing efficiency and scalability in optical networks. Furthermore, it delves into the impact of quantum dot-based single-photon sources, particularly their ability to generate entangled and polarized photons, in driving advancements across quantum technologies.

Comparisons of aged samples and modern references provide algorithm for mtDNA analysis in challenging material

Dissecting the properties of circulating IgG against streptococcal pathogens through a combined systems antigenomics-serology workflow

Abstract This study showcases an integrative mass spectrometry-based strategy combining systems antigenomics and systems serology to characterize human antibodies in clinical samples. This strategy involves using antibodies circulating in plasma to affinity-enrich antigenic proteins in biochemically fractionated pools of bacterial proteins, followed by their identification and quantification using mass spectrometry. A selected subset of the identified antigens is then expressed recombinantly to isolate antigen-specific IgG, followed by characterization of the structural and functional properties of these antibodies. We focused on Group A streptococcus (GAS), a major human pathogen lacking an approved vaccine. The data shows that both healthy and GAS-infected individuals have circulating IgG against conserved streptococcal proteins, including toxins and virulence factors. The antigenic breadth of these antibodies remains relatively constant across healthy individuals but changes considerably in GAS bacteremia. Moreover, antigen-specific IgG analysis reveals individual variation in titers, subclass distributions, and Fc-signaling capacity, despite similar epitope and Fc-glycosylation patterns. Finally, we show that GAS antibodies may cross-react with Streptococcus dysgalactiae (SD), a bacterial pathogen that occupies similar niches and causes comparable infections. Collectively, our results highlight the complexity of GAS-specific antibody responses and the versatility of our methodology to characterize immune responses to bacterial pathogens.

Thermodynamic coupling in micro-nanocavity graphene/paraffin phase change energy storage materials under impact loading

Micro-nanocavity graphene/paraffin nanocomposites (MNGPNs) are emerging as promising phase change materials for passive thermal management in electronics, utilizing the superior thermal conductivity of graphene in conjunction with the excellent heat storage capacity of paraffin. However, current assessments of MNGPNs thermal management performance are primarily conducted under laboratory static conditions, which do not fully represent the complex overload environments encountered in practical applications. In this study, we conducted strain freezing experiments using a split Hopkinson pressure bar and performed recovery analysis to investigate the influence of dynamic loading on thermal behavior through postmortem microstructural characterizations. Our findings reveal significant thermodynamic coupling effects in the in-plane direction, while coupling effects in the out-of-plane direction were less apparent. Specifically, the increase in internal thermal resistance under impact loading, due to the cracking, shedding, and directional changes in the graphene structure, diminishes the heat transfer capacity of MNGPNs in the in-plane direction. Alternations in interfacial thermal resistance caused by the layer compression and shedding affect the out-of-plane heat transfer capacity. Furthermore, the thermal behavior of MNGPNs was validated through heat dissipation experiments. This work provides valuable insights for the practical thermal management applications of MNGPNs, highlighting their performance from a dynamic perspective.

Based on model randomization and adaptive defense for federated learning schemes

Atomic mechanism of lithium dendrite penetration in solid electrolytes

Impact of growth temperature on heterostructure interface steepness in ultraviolet-B AlGaN-based laser diodes

This study investigates the steepness of the heterostructure interface between the p-side optical-waveguide and electron blocking layer (EBL) in ultraviolet-B (UV-B) laser diodes (LDs), focusing on the impact of growth temperature. The results revealed that lowering the growth temperature significantly reduced the thickness of the “unintended compositionally graded layer” a diffusion layer formed at the interface through solid-phase diffusion. However, a bottleneck also existed in LDs with extremely steep interfaces, where the diode characteristics could not be obtained due to the device's high resistance. This study highlights the trade-off between the steepness of the interfaces in the AlGaN heterostructure and diode performance, indicating the need for further optimization to achieve high-performance UV-B LDs. Specifically, future efforts should focus on refining growth conditions to reduce impurity concentrations resulting from low-temperature growth and controlling the thickness of individual layers, such as the EBL, to address high resistance and achieve high-performance UV-B LDs.

An integrated CSPPC and BiLSTM framework for malicious URL detection

The deubiquitylating enzyme Fat facets promotes Fat signalling and restricts tissue growth

Abstract Tissue growth is regulated by many signals, including polarity cues. The Hippo signalling pathway restricts tissue growth and receives inputs from the planar cell polarity-controlling Fat signalling pathway. The atypical cadherin Fat restricts growth via several mechanisms that ultimately control the activity of the pro-growth transcriptional co-activator Yorkie. Fat signalling activates the Yorkie inhibitory kinase Warts, and modulates the function of the FERM protein Expanded, which promotes Hippo signalling and also directly inhibits Yorkie. Although several Fat pathway activity modulators are known to be involved in ubiquitylation, the role of this post-translational modification in the pathway remains unclear. Moreover, no deubiquitylating enzymes have been described in this pathway. Here, using in vivo RNAi screening, we identify the deubiquitylating enzyme Fat facets as a positive regulator of Fat signalling with roles in tissue growth control. Fat facets interacts genetically and physically with Fat signalling components and regulates Yorkie target gene expression. Thus, we uncover a role for reversible ubiquitylation in the control of Fat signalling and tissue growth regulation.

Nonlinear response of hybrid magnons in synthetic antiferromagnets

In this study, we investigated the nonlinear response of hybrid magnons consisting of acoustic and optic magnon modes in in-plane magnetized synthetic antiferromagnets. Using the heterodyne magneto-optical Kerr effect technique, we optically measured the properties of hybrid magnons under various excitation powers. These measurements revealed that the increase in the excitation power changed the resonance spectrum and the intensity distribution of the magnon dispersion relation due to the nonlinear dynamics of propagating magnons. This study advances the understanding of the nonlinear behavior of hybrid magnons, contributing to the future development of magnonic logic circuits and quantum devices.

Identification of quantitative trait nucleotides for grain quality in bread wheat under heat stress

Enhanced AlGaN/GaN ultraviolet phototransistor: Achieving single-pixel imaging and communication

The ideal combination of high sensitivity and fast response speed is crucial for advanced photodetectors. Herein, we present a normally-off, visible-blind ultraviolet (UV) AlGaN/GaN phototransistor featuring a fluorine-ion-implanted trench gate structure. This design effectively disrupts the conductive channel of the AlGaN/GaN heterostructure, drastically reducing the dark current to the magnitude of 0.1 pA. The trench structure enhances the localized electric field in the confined gate region, significantly improving UV detection sensitivity. Additionally, the finite electric field enhancement induced from fluorine ions (F− ions) accelerates the establishment of photogenerated electron channels. Consequently, the phototransistor exhibits ultrafast response speed, with rise and decay times of 1.5 and 6.7 μs, respectively, along with an exceptional specific detectivity of 3.45 × 1016 cm·Hz1/2 W−1. The detection of weak UV light reaches as low as 76.0 nW/cm2. This remarkable detection capability allows the device to perform high-fidelity single-pixel imaging and facilitates real-time UV communication. The proposed AlGaN/GaN phototransistor, characterized by a straightforward fabrication process and excellent photoresponse performance, presents enticing prospects for multiple performance compatible optoelectronic devices.

Study on negative friction of pile foundation in homogeneous layered soil in collapsible loess area

High temperature complementary heterojunction tunnel field-effect transistors for low-power circuits

Tunnel field-effect transistor (TFET) is emerging as a promising alternative to overcome the thermionic limit of 60 mV/dec in subthreshold swing (SS) inherent to metal-oxide-semiconductor field-effect transistor through the band-to-band tunneling (BTBT) mechanism. TFET offers significant potential for applications in future industries, such as low-power sensors and wearable devices, where extreme energy efficiency is critical. Notably, due to the characteristic of the BTBT mechanism, TFET can maintain stable SS performance even at high temperature, enabling low-power operation under such condition. Although numerous theoretical predictions and simulations support this capability, experimental validation has not yet been demonstrated. As electric and autonomous vehicles advance, the demand for automotive semiconductors has increased, highlighting the importance of transistor technology that remains stable at high temperatures and consumes less power. Here, we report high temperature TFETs showing SS < 60 mV/dec through vertical heterojunction of two-dimensional semiconductors. n-TFET and p-TFET were implemented via BP-MoS2 and WSe2-ReS2 heterojunction, respectively. Both TFETs reached SSmin under 50 mV/dec at room temperature and maintained SS1dec_avg under 60 mV/dec up to 400 K. These findings pave the way for low-power circuits capable of operation in harsh environments.

How adaptive social robots influence cognitive, emotional, and self-regulated learning

Abstract As educational environments become more diverse, adaptive technologies like social robots hold promise for providing individual support to learners. This study investigated the role of adaptive teaching of a robot on students’ learning outcomes, emotions, and self-regulated learning (SRL). A total of 120 participants (aged 18–60 years, M age = 30.25, SD age = 10.06, 64.3% female) engaged in an interactive vocabulary learning task with varying guidance levels by the robot. Control conditions included fixed guidance, offering either simple guidance with no hints (condition 1) or enhanced guidance, constantly adding hints (condition 2). In the adaptive conditions, the robot adjusted the number of hints based on learners’ recent performance and enjoyment (condition 3) or additionally personalized hints to specific mistakes (condition 4). The results showed no direct or indirect effects of adaptive guidance on task performance or cognitive learning compared to fixed guidance. Instead, adaptive guidance significantly reduced on-task enjoyment compared to enhanced guidance, suggesting that unexpected variability in robot behavior may negatively affect emotional learning experience. However, personalized adaptive guidance increased certain SRL behaviors, indirectly benefiting learning outcomes. These findings highlight the need for further refinement of adaptive social robots to better meet individual learner needs and optimize outcomes.

Piezo-strain induced nonvolatile control of magnetic skyrmion nonlinear dynamics for artificial synapse device applications

High-performance artificial synaptic devices that emulate the functions of biological synapses are crucial for advancing energy-efficient brain-inspired computing systems. Current studies predominantly focus on memristive devices, which achieve synaptic functions through nonvolatile electric current-assisted carrier modulation. However, these methods often suffer from excessive energy consumption. Here, a type of low-energy-consumption artificial synapse based on strain-mediated electric-field control of magnetic skyrmion's radius is demonstrated, where the energy consumption is 10 fJ per state and the non-volatility is achieved by local ferroelectric domain switching under bipolar electric fields. The proposed skyrmion-based synaptic device can replicate essential synaptic behaviors, including long-term potentiation (LTP), long-term depression (LTD), paired-pulse facilitation, paired-pulse depression, and spiking-time-dependent plasticity, aligning it closely with the biological synaptic system. The synaptic weight change and non-linearity of the artificial synapse are emulated by modulating the magnetic skyrmion's radius through precisely engineering the applied electric-field pulses. Simulation using the Modified National Institute of Standards and Technology database reveals that the pattern recognition rate decreases exponentially with increasing LTP/LTD non-linearity, quantifying the effect of the LTP/LTD non-linearity on the pattern recognition rate. This work underscores the potential of strain-mediated electric-field control of single skyrmion's radius as a groundbreaking approach for developing high density and low-energy consumption artificial synaptic devices.

Stigma toward people living with HIV among healthcare providers in midwifery hospitals in Shenzhen, China from 2020 to 2023

On the dependence of internal stress on dislocation inclination pattern in HVPE-GaN substrates

Internal stress in gallium nitride (GaN) induced during epitaxy growth can degrade the performance of GaN devices. This work studied the internal stress distribution and dislocation configuration around an inclusion of ∼300 μm in GaN substrates grown by hydride vapor phase epitaxy, by means of combined Raman spectroscopy, x-ray topography, and two-photon excitation photoluminescence. The inclusion-induced internal stress decreased exponentially along the radial direction. However, the internal stress, though reduced to a small magnitude, was unexpectedly maintained and propagated over long distances. A stress localization phenomenon, which was out of the prediction of classic elasticity theory, was also observed. The inclination of threading dislocations was found to be substantially influenced by the unreported distribution of internal stress. Four characteristic dislocation inclination patterns were identified: the two-short-tooth pattern, two-long-tooth pattern, gear pattern, and sun-like pattern. The dependence of internal stress on the dislocation inclination pattern was revealed. Based on this dependence, a method to predict the stress field in crystal based on dislocation pattern without corrosion was proposed.