Browse Articles

Inelastic-stress-induced threshold instability and mobility degradation in AlN/GaN MIS-HEMTs on Si

This work investigates the impact of stress-induced effects on the stability of AlN/GaN MIS-HEMTs on Si employing PECVD-SiN as a passivation layer. DC and temperature-dependent C–V/I–V measurements together with technology computer-aided design simulations are used to correlate stress state, defect behavior, and channel transport. As-deposited PECVD-SiN introduces strong inelastic stress that compresses the 2DEG near the GaN surface and drives an anomalous reverse shift of the threshold voltage of ∼−0.3 V between 300 and 475 K, with room-temperature mobility limited to ∼700 cm2 V−1 s−1 by remote scattering. Arrhenius analysis of the drain current yields an activation energy Ea = 0.059 eV, attributed to thermally activated charging and restructuring of bulk and interface defects coupled to the stress field. Post-passivation annealing at 450 °C largely relaxes the inelastic component, broadens the potential well, and reduces Ea to 0.019 eV. The mobility increases to ∼1260 cm2 V−1 s−1 and exhibits a polar optical phonon-like temperature dependence, while the VTH–T behavior changes to a weak positive coefficient. These results offer insights on the temperature stability of stress-induced GaN MIS-HEMTs from a material perspective.

Structure and air permeability of polyamide and polyester parachute fabrics

Photochemical N‐dealkylation of Tertiary Amines Coupled With Photocharging of Poly(Heptazine Imides)

ABSTRACT Photocharging in carbon nitride materials is emerging as a promising route for light‐driven energy storage, yet the nature of the storage sites and their mechanisms remain elusive. Here, we investigate photocharging in poly(heptazine imide) (PHI), focusing on its protonated (H‐PHI) and sodium (Na‐PHI) forms. Using the photochemical dealkylation of triethylamine, we quantify the density of electron–proton (e − /H + ) pairs stored in these materials and define a descriptor, N e : N hept , to track photocharging at the molecular level. H‐PHI demonstrates superior electron storage and reactivity, attributed to its microporous 2D structure and favorable energetics. Theoretical modeling, combined with spectroscopic analysis, reveals the nature of the active heptazine sites and their transformation during charging. The material retains its structural and functional integrity across multiple cycles, underscoring its stability and recyclability. These insights open new avenues for the rational design of carbon nitride‐based semiconductors for light‐induced redox applications.

Habitual coffee consumption poorly correlates with sleep quality and daytime sleepiness: A cross-sectional study

Coffee is the most common drink in the world, second only to water. This makes caffeine, the ingredient of coffee known for its wakefulness-promoting effects, one of the most used psychoactive substances. The psychoactive property of caffeine is well-characterized, and entails its interaction with the adenosine receptors, involved in sleep regulation. While studies have shown a deleterious immediate effect of caffeine on sleep, less is known about the effects of chronic caffeine exposure. In the present cross-sectional study, we investigated this relationship across a large cohort of 30,154 individuals participating in the Swedish Cardiopulmonary Bioimage Study (SCAPIS), which allowed us to compare habitual coffee intake with sleep habits, subjective estimate of daytime sleepiness, and underlying genetic variants. According to our analyses, different degrees of coffee consumption, confirmed by statistical association with previously reported genetic variants, showed very low association with estimated patterns of sleep habits or perceived daytime sleepiness. These results indicate that coffee may be less impactful on sleep habits than previously thought, or that other mechanisms, such as the adaptive capabilities of the adenosine system in adult coffee users, may dampen its psychoactive potency.

Magnetic aftereffect and Barkhausen jumps in thin altermagnetic Mn5Si3 films

In ferromagnets, the anomalous Hall effect (AHE) can exhibit time-dependent relaxation, including magnetic aftereffect and Barkhausen jumps, and thus provide insights into magnetic susceptibility and domain dynamics. Recently, a finite AHE has also been reported in compensated collinear magnets—termed altermagnets—which, due to their spin and crystal symmetries, combine properties usually attributed to either ferromagnets or antiferromagnets. To date, a possible time-dependent relaxation of the AHE in altermagnets has not been explored. Here, we study the Hall effect response of micrometer-scale Hall bars patterned into thin films of Mn5Si3, an altermagnet featuring a finite spontaneous AHE. Recording transport data as a function of time, at a fixed magnetic field magnitude, we observe a relaxation of the Hall voltage qualitatively and quantitatively similar to the magnetic aftereffect in ferromagnetic films. In addition, the Hall voltage time traces feature clear unidirectional jumps, which we interpret as Barkhausen jumps, i.e., as experimental evidence for abrupt reorientations of Hall vector domains in Mn5Si3. A quantitative analysis yields a Barkhausen length of around 18 nm in the Hall bar devices with the smallest width of 100 nm.

The role of reactivations during consolidation in the structure and accessibility of episodic autobiographical memories

Electrocatalytic Nitrate Reduction to Hydroxylamine: Breaking the Activity‐Selectivity Trade‐Off by Designer Bifunctional Metal‐Organic Frameworks

ABSTRACT Electrocatalytic nitrate reduction reaction (NitRR) offers a promising route for hydroxylamine (NH 2 OH) synthesis under ambient conditions. However, the inherent activity‐selectivity trade‐off limits the overall performance. To overcome this challenge, a bimetallic NiMg‐MOF‐74 electrocatalyst is designed for NH 2 OH production via NitRR with high performance. Experimental and theoretical investigations have unraveled the synergy of dual active sites in promoting NO 3 − to NH 2 OH conversion. The electron‐sufficient Ni (2‐δ)+ site weakens the binding of *NH 2 OH intermediate and minimizes its excessive reduction to undesired NH 3 byproduct. Moreover, the electron‐deficient Mg (2+δ)+ site with higher charge density than Ni (2‐δ)+ facilitates hydration and hydrogenation steps of N─O species over proximal Ni (2‐δ)+ site, thus the overall activity for NH 2 OH formation is increased. The concurrently enhanced selectivity and activity result in a high Faradaic efficiency of 92.3% and an unprecedented NH 2 OH yield rate of 55.1 mg h −1 cm −2 in a flow reactor, which can be directly utilized for the preparation of value‐added oxime compounds. Further, the coupling of NitRR with photovoltaics in one system enables bias‐free NH 2 OH production with a high solar‐to‐NH 2 OH efficiency of 17.74%. Our work offers advanced electrocatalysts and new insights for sustainable NH 2 OH electrosynthesis.

Expression of Concern: Effect of daily physical activity on ambulatory blood pressure in pregnant women with chronic hypertension: A prospective cohort study protocol

Double drift layers to minimize on-resistance in 2.7-kV <i>β</i> -Ga2O3 (001) vertical trench Schottky barrier diodes

Improved specific on-resistance (Ron,sp) in beta-gallium oxide (β-Ga2O3) trench Schottky barrier diodes (TSBDs) is achieved without the usual trade-off of reduced breakdown voltage, enabled through the use of a double drift layer (DDL) TSBD architecture; this incorporates a Si-doped drift layer atop an unintentionally doped (UID) drift region. DDL TSBDs show a 46% reduction in Ron,sp compared to single-UID drift layer TSBDs, while maintaining a similar Vbr of 2.6–2.7 kV. As a result, the DDL TSBD design enhances Baliga's figure-of-merit from 481 MW/cm2 for conventional TSBDs to 959 MW/cm2, marking a twofold improvement. Silvaco TCAD simulations further confirm that both structures exhibit similar dominant peak electric fields at the trench corners, consistent with their comparable breakdown voltages. While reducing fin width in TSBDs enhances Vbr because of an improved reduced surface field effect, we demonstrate that this effect is significantly amplified in DDL TSBDs, enabling a substantial shift in the conventional Ron,sp–Vbr trajectory.

Correction: Genome-wide identification and evolutionary analysis of the AP2/EREBP, COX and LTP genes in Zea mays L. under drought stress

Alternately Twisted, Electron‐Rich Rylenes and Their Stable Cations

ABSTRACT Solution‐phase synthesis of long rylenes remains challenging due to their strong tendency to aggregate. Introducing backbone twist can reduce aggregation and simultaneously generate potential helical chirality. Herein, we report a series of rylene molecules–up to octarylene—bearing both odd‐ and even‐numbered naphthalene units and multiple n ‐butoxy substituents at the bay/ortho positions, synthesized via stepwise cross‐coupling followed by controlled oxidative dehydrogenation. Peri ‐attached 4‐(trifluoromethyl)phenyl groups further stabilize the extended scaffolds. The electron‐rich n ‐butoxy groups not only induce pronounced backbone twisting but also impart strong electron‐donating character. X‐ray crystallography reveals that long rylenes with two or more bay‐ tetra( n ‐butoxy) motifs adopt alternating P / M helicity rather than a homochiral helical conformation. These molecules exhibit clear length‐dependent optical and electrochemical properties, with absorption and emission spanning the visible to near‐infrared region. Their electron‐rich nature enables facile formation of stable radical cations and dications. Solid‐state structures of representative radical cations show distinct intermolecular stabilizing interactions, while 1 H NMR and ACID analyses of the dications reveal a systematic evolution from local to global aromaticity.

Correction: Methionine-Restricted C57BL/6J Mice Are Resistant to Diet-Induced Obesity and Insulin Resistance but Have Low Bone Density

Latent transition unlocks visible-to-ultraviolet upconversion for covert optical security

Upconversion luminescence (UCL) is transforming the landscape of optical anti-counterfeiting, particularly in the ultraviolet (UV) range, where invisible emissions enable highly advanced security features. Yet, scarce UV-emitting pathways have historically hindered significant progress in this area. Here, we present an intriguing finding: when LiLuGeO4 phosphors co-doped with Pr3+ and Bi3+ ions are excited with blue lasers, they unexpectedly emit UV radiation at 352 nm—a feature absent in singly doped counterparts. We attribute the previously unrecognized UV emission to a process we term “latent transition energy transfer” (LTET). In this mechanism, Pr3+ sensitizes Bi3+ without itself emitting UV light and without requiring spectral overlap, thereby bypassing conventional energy-transfer bottlenecks. Building on this insight, we have observed similar LTET-driven UCL behavior in other ion pairs (Pr3+–Tb3+ and Pr3+–Gd3+) within appropriate host materials. Demonstrated via UV imaging for security, this discovery unveils a new class of UV-emitting materials that enhance anti-counterfeiting and spectral control in luminescent systems.

Geospatial patterns and socio-environmental factors of household overcrowding in Ethiopia: Evidence from 2019 Ethiopian demographic and health survey data

Surface‐Assisted Wurtz Coupling for the Stereoselective Synthesis of Covalent Organic Frameworks

ABSTRACT Surface‐confined precision synthesis of 2D covalent organic frameworks (COFs) represents a crucial bridge connecting molecular design with macroscopic material properties. In this work, we achieve the first surface‐confined synthesis of monolayer COF via Wurtz coupling, demonstrating prominent stereoselectivity through temperature modulation. At reduced temperature (78 K), the reaction preferentially follows a trans ‐coupling pathway, enabling the successful synthesis of metastable COF that maintains structural integrity during thermal treatment due to surface confinement. Conversely, deposition at elevated temperature (298 K) promotes thermodynamically stable cis ‐coupling porous nanoribbons. Combined ultrahigh‐vacuum scanning tunneling microscopy (UHV‐STM) and density functional theory (DFT) calculations elucidate the fundamental thermodynamic‐kinetic competition mechanism governing the C‐C coupling reactions at the molecular level: while the trans ‐coupling pathway benefits from a lower activation barrier, the cis ‐coupling configuration represents the thermodynamic minimum. Notably, this synthetic approach demonstrates pronounced generality, as confirmed by its successful implementation with another triphenylbenzyl bromide precursor to yield monolayer COF. This work deepens the understanding of irreversible bond formation in on‐surface synthesis and establishes kinetic trapping as a powerful strategy for achieving precise stereoselective control in Wurtz coupling.

Racial differences in people living with HIV and Heart Failure: Insight from New York City health and hospitals HIV Heart Failure Cohort

Background Racial disparities, an imbalance between the treatment of racial groups, in healthcare significantly affect the prognosis and treatment outcomes for people living with HIV (PLHIV) and heart failure (HF). The complexity of racial disparities in health care is exacerbated when social determinants of health (SDoH). Utilizing the New York City Health and Hospitals HIV Heart Failure (NYC 4H) cohort, one of the largest public health providers in New York City, this study aims to describe the epidemiological characteristics, treatment, and mortality differences among various racial groups in patients living with HIV (PLHIV) and HF. Methods This study utilized data from the mixed retrospective and prospective NYC 4H cohort, comprised of adult individuals with confirmed HIV and HF from inpatient or clinic visits between July 2017 and June 2022. from eleven major New York City Health and Hospitals. Racial identification was reported by the patients. Social adversities (SA) were assessed through a psychosocial evaluation conducted by licensed clinical social workers (LCSWs) during the initial clinic or hospital encounter within the enrollment period. Each patient’s home address was mapped to the area deprivation index (ADI) to obtain ADI ranking and further characterize socioeconomic disadvantage. We assessed the relationship between social adversities and overall mortality in each racial group using hazard ratios (HRs) derived from proportional hazard regression models. Results In total, 1044 patients, including 631 Black/African American, 289 Hispanic/Latino, 57 non-Hispanic White, 17 Asian/Pacific Islander, and 50 of unknown or other racial backgrounds were analyzed in the study. An average follow-up time is 3.8 years. Significant racial difference in ischemic cardiomyopathy, with the highest occurrence found in the Black/African American group (51%) were noticed comparing to Asian/Pacific Islander (2.3%) and Other/Unknown groups (5.6%) (P &lt; 0.001). The rate of coronary artery bypass grafting (CABG) among the African American population (1.9%) is notably lower (P &lt; 0.001) compared to other racial groups. Based on state-wide ADI ranking, all patients disproportionately clustered in the most disadvantaged neighborhood areas, however patients identifying as Black/African American and Hispanic/Latino were more likely to reside in areas with higher ADI score. Asian/Pacific Islander populations have experienced fewer social adversities, with 76.5% reporting no encounters with social adversity, compared to 41% for Black/African American, 44.3% for Hispanic/Latino, 45.6% for non-Hispanic White, and 34% for Other/Unknown groups . Non-Hispanic White group exhibited a higher prevalence of LGBTQ individuals at 10.5%, a identity not commonly listed among the top challenge for other racial groups (P = 0.002). During the follow-up period, a total of 259 deaths were recorded. The mortality rate is lowest in Asian/Pacific Islanders (11.8%), while comparing to non-Hispanic Whites (33.3%) and unknown or other races (50%). Conclusions Significant differences exist in comorbidities, disease management, and social conditions among HIV and heart failure patients across five racial groups. The findings suggest that within impoverished multiethnic communities, it is crucial to conduct comprehensive screenings for social adversities across all racial groups, as social disadvantage may manifest in various ways.

Microarc oxidation layer on aluminum surface significantly suppresses partial discharge at triple junction point on insulation surface

The surface discharge at metal/insulation/gas (or vacuum) triple junctions (TJs) poses a serious threat to the insulation reliability of high-voltage equipment. An insulation layer was fabricated on the surface of aluminum metal electrodes via microarc oxidation (MAO) to suppress surface discharge at the TJ. The partial discharge inception voltage was effectively increased by up to 54.5% with the MAO layer. At 1.5 kV, the average discharge magnitude per minute at the TJ decreased by up to 66.7% after MAO treatment. The composition of the insulation layer is primarily Al2O3 and Al2SiO5. As the MAO duration and voltage increase, the thickness and surface pore area ratio of the MAO layer increased continuously. The mechanism of partial discharge suppression was investigated by analyzing the layer's composition, resistivity, surface potential decay, and phase-resolved partial discharge spectrum. The analysis indicates that the mechanism primarily involves suppressing the direct or indirect movement of electrons from the metal electrode to the gas. Consequently, this suppression reduces both the number of seed charges for electron avalanches and the probability of avalanche initiation at the microscopic level. At the macro-level, the insulation layer eliminates the traditional TJ, establishing a TJ of insulation/insulation/gas (or vacuum). This work proposes a strategy for suppressing surface discharges at TJs through metal surface modification.

Large-scale distribution of cestode infections in wild gentoo penguins and their impact on the host microbiome

Abstract Intestinal helminths often cause chronic infections, which can impact health and productivity, particularly when combined with other stressors including the environmental challenges faced by polar species. Here we employed a faecal DNA amplicon-sequencing-based approach to study on the epidemiology of tapeworms (Cestoda) in gentoo penguins sampled from colonies within the Scotia Arc. Overall, 325 faecal samples were collected from gentoo penguins at 25 locations and screened for cestode sequences within a pan-eukaryote 18S DNA profile. Four different core groups of sequences were identified as frequently occurring in the dataset, which likely represent different species or groups of cestodes. The proportion of cestode DNA reads was highly variable, displaying an over-dispersed distribution. The proportion of cestode DNA correlated with differences in microbiome composition, suggesting that these infections may influence gut microbiota or vice versa, with broader consequences for penguin health and resilience. This study highlights the need for a comprehensive understanding of both direct and indirect effects of helminths on individual and population health.

Steering Ethylene Electrosynthesis by Controlling Interfacial Water Orientation

ABSTRACT Controlling reaction pathway via solvent polarization dynamics remains a grand challenge in catalysis due to elusive interfacial kinetic regulation mechanisms. Here, we resolve this dilemma by establishing interfacial water orientation that directly couples H 2 O polarization with reaction pathway bifurcation. Using electrocatalytic CO 2 reduction as a typical platform, we demonstrate that precisely engineered H‐down water alignment, achieved via adaptive subsurface tuning (AST) strategy of Ga‐doped Cu catalysts, dynamically regulates proton transfer directionality and intermediate stabilization. The optimized Ga/Cu catalyst achieved a Faradaic efficiency (FE) of 68.8% for ethylene at 800 mA cm −2 , surpassing ethanol production by 8.2‐fold, and the current density was among the highest reported for catalysts with high ethylene FE. Detailed experimental studies and theoretical calculations corroborate that H‐down alignment enhanced *H availability, directing protons to selectively cleave the C─O bond of *CHCOH intermediates over hydrogenation pathways, yielding high ethylene FE and current density. These findings establish interfacial water orientation as a pivotal descriptor for steering C─C coupling selectivity in electrocatalysis, offering a rational design principle for efficient electroreduction systems.

Patient-derived organoids predict chemotherapy response of locally advanced gastric cancer

The efficacy of standard adjuvant chemotherapy for locally advanced gastric cancer (GC) remains suboptimal, particularly in patients with signet-ring cell carcinoma (SRCC). Urgent demand exists for reliable preclinical models to predict therapeutic responses, and in vitro drug sensitivity testing using patient-derived organoids (PDOs) has emerged as a promising platform. In this study, PDOs were established from patients with locally advanced GC and analyzed via next-generation sequencing (NGS) and pharmacotyping. Seventeen GC PDOs were successfully generated, achieving a success rate of 63%. These PDOs closely recapitulated the histopathological and genetic features of their parental tumors. Drug sensitivity tests revealed subtype-specific response patterns: PDOs derived from SRCC were sensitive to epirubicin and paclitaxel but resistant to 5-fluorouracil (5-FU) and oxaliplatin. In contrast, non-SRCC PDOs demonstrated robust sensitivity to paclitaxel, epirubicin, and oxaliplatin. Among all tested drugs, paclitaxel showed the highest tumor-inhibitory efficacy in both subtypes. Furthermore, non-SRCC PDOs were significantly more sensitive to 5-FU and oxaliplatin than SRCC PDOs. Ex vivo pharmacotyping of PDOs accurately predicted clinical therapeutic responses in GC patients, with a sensitivity of 85.7%, specificity of 100%, and accuracy of 90.9%. Notably, patients whose PDOs were drug-sensitive in vitro had significantly longer disease-free survival than those whose PDOs were drug-resistant ( P  = 0.044). These findings highlight the potential of GC PDOs as reliable preclinical models that faithfully recapitulate tumor biology and therapeutic responses, thereby providing a valuable tool for predicting individualized treatment outcomes and advancing precision oncology for GC.